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Papers by Yi-ching Wang

Research paper thumbnail of Rab37 mediates trafficking and membrane presentation of PD-1 to sustain T cell exhaustion in lung cancer

Journal of biomedical science, Feb 7, 2024

Background Programmed cell death protein 1 (PD-1) is an immune checkpoint receptor expressed on t... more Background Programmed cell death protein 1 (PD-1) is an immune checkpoint receptor expressed on the surface of T cells. High expression of PD-1 leads to T-cell dysfunction in the tumor microenvironment (TME). However, the mechanism of intracellular trafficking and plasma membrane presentation of PD-1 remains unclear. Methods Multiple databases of lung cancer patients were integratively analyzed to screen Rab proteins and potential immune-related signaling pathways. Imaging and various biochemical assays were performed in Jurkat T cells, splenocytes, and human peripheral blood mononuclear cells (PBMCs). Rab37 knockout mice and specimens of lung cancer patients were used to validate the concept. Results Here, we identify novel mechanisms of intracellular trafficking and plasma membrane presentation of PD-1 mediated by Rab37 small GTPase to sustain T cell exhaustion, thereby leading to poor patient outcome. PD-1 colocalized with Rab37-specific vesicles of T cells in a GTP-dependent manner whereby Rab37 mediated dynamic trafficking and membrane presentation of PD-1. However, glycosylation mutant PD-1 delayed cargo recruitment to the Rab37 vesicles, thus stalling membrane presentation. Notably, T cell proliferation and activity were upregulated in tumorinfiltrating T cells from the tumor-bearing Rab37 knockout mice compared to those from wild type. Clinically, the multiplex immunofluorescence-immunohistochemical assay indicated that patients with high Rab37 + /PD-1 + /TIM3 + / CD8 + tumor infiltrating T cell profile correlated with advanced tumor stages and poor overall survival. Moreover, human PBMCs from patients demonstrated high expression of Rab37, which positively correlated with elevated levels of PD-1 + and TIM3 + in CD8 + T cells exhibiting reduced tumoricidal activity. Conclusions Our results provide the first evidence that Rab37 small GTPase mediates trafficking and membrane presentation of PD-1 to sustain T cell exhaustion, and the tumor promoting function of Rab37/PD-1 axis in T cells of TME in lung cancer. The expression profile of Rab37 high /PD-1 high /TIM3 high in tumor-infiltrating CD8 + T cells is a biomarker for poor prognosis in lung cancer patients.

Research paper thumbnail of Estradiol-mediated inhibition of Sp1 decreases miR-3194-5p expression to enhance CD44 expression during lung cancer progression

Journal of Biomedical Science, Jan 17, 2022

Research paper thumbnail of High-CLDN4 ESCC cells harbor stem-like properties and indicate for poor concurrent chemoradiation therapy response in esophageal squamous cell carcinoma

Therapeutic Advances in Medical Oncology, 2019

Background: Esophageal squamous cell carcinoma (ESCC) is the major type of esophageal cancer in A... more Background: Esophageal squamous cell carcinoma (ESCC) is the major type of esophageal cancer in Asia and demonstrates poor survival rates following a therapeutic regimen. Methods: Cancer stem cells (CSCs) are responsible for tumor initiation, progression, and treatment failure in cancers. Therefore, identification and characterization of CSCs may help to improve clinical outcomes for ESCC patients. Tumor sphere formation assay are performed to isolate cancer stem-like ESCC cells. QRT-PCR, tumor initiation, metastasis, CCRT treatment are used to evaluate ESCC cells’ stemness properties in vitro and in vivo. Results: The authors’ data demonstrates that cancer stem-like ESCC cells harbored stemness characteristics including self-renewal, differentiation, and transdifferentiation, and possess tumor initiation, metastasis, and treatment inefficiency properties. For the identification of useful biomarkers of cancer stem-like ESCC cells, the authors further identified that CLDN4 was upregu...

Research paper thumbnail of IL-33/NF-κB/ST2L/Rab37 positive-feedback loop promotes M2 macrophage to limit chemotherapeutic efficacy in lung cancer

Cell death and disease, May 22, 2024

Research paper thumbnail of Dysregulation of SOX17/NRF2 axis confers chemoradiotherapy resistance and emerges as a novel therapeutic target in esophageal squamous cell carcinoma

Journal of Biomedical Science

Background Esophageal squamous cell carcinoma (ESCC) is the sixth leading cause of cancer-associa... more Background Esophageal squamous cell carcinoma (ESCC) is the sixth leading cause of cancer-associated death worldwide with a dismal overall 5-year survival rate of less than 20%. The standard first-line therapy for advanced ESCC is concomitant chemo-radiation therapy (CCRT); however, patients usually develop resistance, resulting in unfavorable outcomes. Therefore, it is urgent to identify the mechanisms underlying CCRT resistance and develop effective treatment strategies. Methods Patients’ endoscopic biopsy tumor tissues obtained before CCRT treatment were used to perform RNA-seq and GSEA analysis. Immunohistochemical (IHC) staining, chromatin immunoprecipitation (ChIP), and promoter reporter analyses were conducted to investigate the relationship between SOX17 and NRF2. Xenograft mouse models were used to study the role of SOX17/NRF2 axis in tumor growth and the efficacy of carboxymethyl cellulose-coated zero-valent-iron (ZVI@CMC). Results In this study, a notable gene expression ...

Research paper thumbnail of YAP1 acts as a negative regulator of pro-tumor TAZ expression in esophageal squamous cell carcinoma

Cellular Oncology

Purpose Although YAP1 and TAZ are believed to be equivalent downstream effectors of the Hippo pat... more Purpose Although YAP1 and TAZ are believed to be equivalent downstream effectors of the Hippo pathway, differential expression of YAP1 or TAZ suggests distinct functions during cancer progression. The exact role of YAP1 and TAZ in esophageal cancer, the 6th leading cancer-related mortality in the world, remains elusive. Methods Following single or double manipulation of YAP1 or TAZ expression, we subjected these manipulated cells to proliferation, migration, invasion, and xenograft tumorigenesis assays. We used RT-qPCR and Western blotting to examine their expression in the manipulated cells with or without inhibition of transcription or translation. We also examined the impact of YAP1 or TAZ deregulation on clinical outcome of esophageal cancer patients from the TCGA database. Results We found that YAP1 functions as a tumor suppressor whereas TAZ exerts pro-tumor functions in esophageal cancer cells. We also found a significant increase in TAZ mRNA expression upon YAP1 depletion, b...

Research paper thumbnail of Epigenetic silencing of AATK in acinar to ductal metaplasia in murine model of pancreatic cancer

Clinical Epigenetics, 2020

Background Cancer subtype switching, which involves unclear cancer cell origin, cell fate decisio... more Background Cancer subtype switching, which involves unclear cancer cell origin, cell fate decision, and transdifferentiation of cells within a confined tumor microenvironment, remains a major problem in pancreatic cancer (PDA). Results By analyzing PDA subtypes in The Cancer Genome Atlas, we identified that epigenetic silencing of apoptosis-associated tyrosine kinase (AATK) inversely was correlated with mRNA expression and was enriched in the quasi-mesenchymal cancer subtype. By comparing early mouse pancreatic lesions, the non-invasive regions showed AATK co-expression in cells with acinar-to-ductal metaplasia, nuclear VAV1 localization, and cell cycle suppression; but the invasive lesions conversely revealed diminished AATK expression in those with poorly differentiated histology, cytosolic VAV1 localization, and co-expression of p63 and HNF1α. Transiently activated AATK initiates acinar differentiation into a ductal cell fate to establish apical-basal polarization in acinar-to-du...

Research paper thumbnail of Annexin A2 Silencing Induces G2 Arrest of Non-small Cell Lung Cancer Cells through p53-dependent and -independent Mechanisms

Journal of Biological Chemistry, 2012

Background: Aberrant expression of annexin A2 has been found in several cancers; however, its rol... more Background: Aberrant expression of annexin A2 has been found in several cancers; however, its role in tumorigenesis is unknown. Results: Silencing annexin A2 partly caused p53-regulated cell cycle arrest at the G 2 phase by inactivating JNK/c-Jun signaling. Conclusion: Annexin A2 promotes the cell cycle and cell proliferation in lung cancer in part by inhibiting p53. Significance: This study provides new insight into the tumorigenic role of annexin A2. Annexin A2 (ANXA2) overexpression is required for cancer cell proliferation; however, the molecular mechanisms underlying ANXA2-mediated regulation of the cell cycle are still unknown. ANXA2 is highly expressed in non-small cell lung cancer (NSCLC) and is positively correlated with a poor prognosis. NSCLC A549 cells lacking ANXA2 exhibited defects in tumor growth in vivo and in cell proliferation in vitro without cytotoxicity. ANXA2 knockdown induced cell cycle arrest at G 2 phase. Unexpectedly, ANXA2 silencing increased the expression of p53 and its downstream genes, which resulted in p53-dependent and-independent G 2 arrest. Aberrant JNK inactivation, which was observed in ANXA2-deficient cells, inhibited cell proliferation following G 2 arrest. A lack of ANXA2 caused a loss of JNK-regulated c-Jun expression, resulting in an increase in p53 transcription. These results demonstrate a novel role for ANXA2 in NSCLC cell proliferation by facilitating the cell cycle partly through the regulation of p53 via JNK/c-Jun.

Research paper thumbnail of Secretory autophagy promotes Rab37-mediated exocytosis of tissue inhibitor of metalloproteinase 1

Journal of Biomedical Science

Background Rab37-mediated exocytosis of tissue inhibitor of metalloproteinase 1 (TIMP1), an infla... more Background Rab37-mediated exocytosis of tissue inhibitor of metalloproteinase 1 (TIMP1), an inflammatory cytokine, under serum-depleted conditions which leads to suppression of lung cancer cell metastasis has been reported. Starvation is also a stimulus of autophagic activity. Herein, we reveal that starvation activates Rab37 and induces autophagy. Methods We used an overexpression/knockdown system to determine the relationship between autophagy and Rab37 in vitro and in vivo. The autophagy activity was detected by immunoblotting, transmission electron microscope, autophagosome purification, and immunofluorescence under the confocal microscope. Lung-to-lung metastasis mouse model was used to clarify the role of autophagy and Rab37 in lung cancer. Clinical lung cancer patient specimens and an online big database were analyzed. Results Initially, we demonstrated that active-form Rab37 increased LC3-II protein level (the marker of autophagosome) and TIMP1 secretion. Accordingly, silenc...

Research paper thumbnail of Application of Array-Based Epigenomic Technology for the Identification of Hypermethylated CpG Site in Lung Cancer Patients

Cancer is caused by the accumulation of both genetic and epigenetic changes. Promoter hypermethyl... more Cancer is caused by the accumulation of both genetic and epigenetic changes. Promoter hypermethylation is one of the major epigenetic changes that cause gene inactivation. Aberrant promoter hypermethylation of CpG islands associated with tumor suppressor genes (TSGs) can lead to transcriptional silencing and result in tumorigenesis. The genomic regions with hypermethylation status may possess novel candidate TSGs. We used a microarray-based epigenome-wide methylation analysis called differential methylation hybridization (DMH) to identify the regions of hypermethylation and a chromatin immunoprecipitation (ChIP)-on-chip analysis to identify the regions of condensed or open chromatin in 20 non-small cell lung cancer (NSCLC) patients and several lung cell lines, and have successfully detected several cancer subtype- and stage-specific hypermethylated genes. They may serve as biomarkers for the early detection or prognosis prediction of lung cancer. Using DMH, we identified promoter hy...

Research paper thumbnail of AKT-mediated phosphorylation enhances protein stability and transcription activity of ZNF322A to promote lung cancer progression

Oncogene, 2019

ZNF322A is an oncogenic zinc-finger transcription factor. Our published results show that ZNF322A... more ZNF322A is an oncogenic zinc-finger transcription factor. Our published results show that ZNF322A positively regulates transcription of alpha-adducin (ADD1) and cyclin D1 (CCND1) to promote tumorgenicity of lung cancer. However, the upstream regulatory mechanisms of ZNF322A protein function remain elusive. Here, we demonstrate that AKT could phosphorylate ZNF322A by in vitro kinase assay and cell-based mass spectrometry analysis. Overexpression of AKT promoted ZNF322A protein stability and transcriptional activity, whereas these effects were inhibited by knockdown of AKT or treating with AKT inhibitor. We studied AKT-mediated phosphorylation sites, viz. Thr-150, Ser-224, Thr-234, and Thr-262. ZNF322A phosphorylation at Thr-262 by AKT promoted ZNF322A protein stability thus increased ADD1 promoter activity. Interestingly, phosphorylation at Thr-150, Ser-224, and Thr-234 enhanced transcription activity without affecting protein stability of ZNF322A. Chromatin immunoprecipitation and DNA affinity precipitation assays showed that ZNF322A phosphorylation defective mutants Thr-150A, Ser-224A, and Thr-234A attenuated chromatin binding and DNA binding affinity to ADD1 and CCND1 promoters compared with wild-type ZNF322A. Furthermore, AKT-mediated Thr-150, Ser-224, Thr-234, and Thr-262 phosphorylation promoted lung cancer cell growth and metastasis in vitro and in vivo. Clinically, expression of phosphorylated ZNF322A (p-ZNF) correlated with actively phosphorylated AKT (p-AKT) in tumor specimens from 150 lung cancer patients. Multivariate Cox regression analysis indicated that combined p-AKT and p-ZNF expression profile was an independent factor to predict the clinical outcome in lung cancer patients. Our results reveal a new mechanism of AKT signaling in promoting ZNF322A protein stability and transcriptional activity in lung cancer cell, xenograft, and clinical models.

Research paper thumbnail of CK1δ/GSK3β/FBXW7α axis promotes degradation of the ZNF322A oncoprotein to suppress lung cancer progression

Oncogene, Oct 5, 2017

Overexpression of Cys2His2 zinc-finger 322A (ZNF322A) oncogenic transcription factor is associate... more Overexpression of Cys2His2 zinc-finger 322A (ZNF322A) oncogenic transcription factor is associated with lung tumorigenesis. However, the mechanism of ZNF322A overexpression remains poorly understood. Here, we discover that protein stability of ZNF322A is regulated by coordinated phosphorylation and ubiquitination through the CK1δ/GSK3β/FBXW7α axis. CK1δ and GSK3β kinases sequentially phosphorylate ZNF322A at serine-396 and then serine-391. Moreover, the doubly phosphorylated ZNF322A protein creates a destruction motif for the ubiquitin ligase FBXW7α leading to ZNF322A protein destruction. Overexpression of FBXW7α induces ZNF322A protein degradation, thereby blocks ZNF322A transcription activity and suppresses ZNF322A-induced tumor growth and metastasis in vitro and in vivo. Clinically, overexpression of ZNF322A correlates with low FBXW7α or defective CK1δ/GSK3β-mediated phosphorylation in lung cancer patients. Multivariate Cox regression analysis indicates that patients with ZNF322A...

Research paper thumbnail of A 3D-QSAR Study of Celebrex-Based Pdk1 Inhibitors Using Comfa Method

Journal of the Chinese Chemical Society, 2009

A 3D-QSAR study of celebrex-based compounds of PDK1 inhibitors using comparative molecular field ... more A 3D-QSAR study of celebrex-based compounds of PDK1 inhibitors using comparative molecular field analysis (CoMFA) was carried out. The structures of the compounds were obtained using quantum chemistry calculation. CoMFA calculations for a number of grouped subsets of ...

Research paper thumbnail of Pin1 positively affects tumorigenesis of esophageal squamous cell carcinoma and correlates with poor survival of patients

Journal of Biomedical Science, 2014

Background: Pin1 promotes oncogenesis by regulating multiple oncogenic signaling. In this study, ... more Background: Pin1 promotes oncogenesis by regulating multiple oncogenic signaling. In this study, we investigated the involvement of Pin1 in tumor progression and in the prognosis of human esophageal squamous cell carcinoma (ESCC). Results: We observed that proliferation, clonogenicity and tumorigenesis of CE81T cells were inhibited by Pin1 knockdown. We next analyzed Pin1 expression in clinical ESCC specimens. When compared to the corresponding non-tumor part, Pin1 protein and mRNA levels in tumor part were higher in 84% and 62% patients, respectively. By immunohistochemistry, we identified that high Pin1 expression was associated with higher primary tumor stage (p = 0.035), higher overall cancer stage (p = 0.047) and poor overall survival (p < 0.001). Furthermore, the association between expression of Pin1 and levels of β-catenin and cyclin D in cell line and clinical specimens was evaluated. β-catenin and cyclin D1 were decreased in CE81T cells with Pin1 knockdown. Cyclin D1 level correlated with Pin1 expression in clinical ESCC specimens. Conclusions: Pin1 upregulation was associated with advanced stage and poor prognosis of ESCC. Pin1 knockdown inhibited aggressiveness of ESCC cells. β-catenin and cyclin D1 were positively regulated by Pin1. These results indicated that targeting Pin1 pathway could represent a potential modality for treating ESCC.

Research paper thumbnail of Molecular Diagnostic Markers for Lung Cancer in Sputum and Plasma

Annals of the New York Academy of Sciences, 2006

Lung cancer is the leading cause of cancer deaths worldwide. This study was designed to select mu... more Lung cancer is the leading cause of cancer deaths worldwide. This study was designed to select multiple DNA markers, which have high sensitivity and specificity to serve as biomarkers for diagnosis of lung cancer. We examined the promoter hypermethylation of three tumor suppressor genes by methylation-specific PCR (MSP), and the instability of eight microsatellite markers by loss of heterozygosity (LOH) and microsatellite instability (MSI) analyses in lung tumor tissues and matched sputum specimens from 79 lung cancer patients. On the basis of the results of sensitivity, specificity, and concordance from each marker analyzed, we selected seven biomarkers, which are LOH of D9S286, D9S942, GATA49D12, and D13S170, MSI of D9S942, and methylation of p16 INK4a and RAR␤, from the sputum analyses. These selected etiologically associated biomarkers can potentially be used as supplemental diagnostic biomarkers for early lung cancer detection.

Research paper thumbnail of Global Oct4 target gene analysis reveals novel downstream PTEN and TNC genes required for drug-resistance and metastasis in lung cancer

Nucleic acids research, Jan 18, 2015

Overexpression of Oct4, a stemness gene encoding a transcription factor, has been reported in sev... more Overexpression of Oct4, a stemness gene encoding a transcription factor, has been reported in several cancers. However, the mechanism by which Oct4 directs transcriptional program that leads to somatic cancer progression remains unclear. In this study, we provide mechanistic insight into Oct4-driven transcriptional network promoting drug-resistance and metastasis in lung cancer cell, animal and clinical studies. Through an integrative approach combining our Oct4 chromatin-immunoprecipitation sequencing and ENCODE datasets, we identified the genome-wide binding regions of Oct4 in lung cancer at promoter and enhancer of numerous genes involved in critical pathways which promote tumorigenesis. Notably, PTEN and TNC were previously undefined targets of Oct4. In addition, novel Oct4-binding motifs were found to overlap with DNA elements for Sp1 transcription factor. We provided evidence that Oct4 suppressed PTEN in an Sp1-dependent manner by recruitment of HDAC1/2, leading to activation ...

Research paper thumbnail of Recent advances in conventional and unconventional vesicular secretion pathways in the tumor microenvironment

Journal of Biomedical Science

All cells in the changing tumor microenvironment (TME) need a class of checkpoints to regulate th... more All cells in the changing tumor microenvironment (TME) need a class of checkpoints to regulate the balance among exocytosis, endocytosis, recycling and degradation. The vesicular trafficking and secretion pathways regulated by the small Rab GTPases and their effectors convey cell growth and migration signals and function as meditators of intercellular communication and molecular transfer. Recent advances suggest that Rab proteins govern conventional and unconventional vesicular secretion pathways by trafficking widely diverse cargoes and substrates in remodeling TME. The mechanisms underlying the regulation of conventional and unconventional vesicular secretion pathways, their action modes and impacts on the cancer and stromal cells have been the focus of much attention for the past two decades. In this review, we discuss the current understanding of vesicular secretion pathways in TME. We begin with an overview of the structure, regulation, substrate recognition and subcellular loc...

Research paper thumbnail of Functional EGFR Germline Polymorphisms May Confer Risk for EGFR Somatic Mutations in Non–Small Cell Lung Cancer, with a Predominant Effect on Exon 19 Microdeletions

Cancer Research, 2011

Somatic mutations in the EGFR tyrosine kinase domain play a critical role in the development and ... more Somatic mutations in the EGFR tyrosine kinase domain play a critical role in the development and treatment of non–small cell lung cancer (NSCLC). Strong genetic influence on susceptibility to these mutations has been suggested. To identify the genetic factors conferring risk for the EGFR tyrosine kinase mutations in NSCLC, a case–control study was conducted in 141 Taiwanese NSCLC patients by focusing on three functional polymorphisms in the EGFR gene [−216G/T, intron 1 (CA)n, and R497K]. Allelic imbalance of the EGFR −216G/T polymorphism was also tested in the heterozygous patients and in the NCI-60 cancer cell lines to further verify its function. We found that the frequencies of the alleles −216T and CA-19 are significantly higher in the patients with any mutation (P = 0.032 and 0.01, respectively), in particular in those with exon 19 microdeletions (P = 0.006 and 0.033, respectively), but not in the patients with L858R mutation. The −216T allele is favored to be amplified in both...

Research paper thumbnail of Targeting protumor factor chitinase-3-like-1 secreted by Rab37 vesicles for cancer immunotherapy

Theranostics, 2022

Background: Chitinase 3-like-1 (CHI3L1) is a secretion glycoprotein associated with the immunosup... more Background: Chitinase 3-like-1 (CHI3L1) is a secretion glycoprotein associated with the immunosuppressive tumor microenvironment (TME). The secretory mode of CHI3L1 makes it a promising target for cancer treatment. We have previously reported that Rab37 small GTPase mediates secretion of IL-6 in macrophages to promote cancer progression, whereas the roles of Rab37 in the intracellular trafficking and exocytosis of CHI3L1 are unclear. Methods: We examined the concentration of CHI3L1 in the culture medium of splenocytes and bone marrow derived macrophages (BMDMs) from wild-type or Rab37 knockout mice, and macrophage or T cell lines expressing wild type, active GTP-bound or inactive GDP-bound Rab37. Vesicle isolation, total internal reflection fluorescence microscopy, and real-time confocal microscopy were conducted. We developed polyclonal neutralizing-CHI3L1 antibodies (nCHI3L1 Abs) to validate the therapeutic efficacy in orthotopic lung, pancreas and colon cancer allograft models. Multiplex fluorescence immunohistochemistry was performed to detect the protein level of Rab37 and CHI3L1, and localization of the tumor-infiltrating immune cells in allografts from mice or tumor specimens from cancer patients. Results: We demonstrate a novel secretion mode of CHI3L1 mediated by the small GTPase Rab37 in T cells and macrophages. Rab37 mediated CHI3L1 intracellular vesicle trafficking and exocytosis in a GTP-dependent manner, which is abolished in the splenocytes and BMDMs from Rab37 knockout mice and attenuated in macrophage or T cell lines expressing the inactive Rab37. The secreted CHI3L1 activated AKT, ß-catenin and NF-κB signal pathways in cancer cells and macrophages to foster a protumor TME characterized by activating M2 macrophages and increasing the population of regulatory T cells. Our developed nCHI3L1 Abs showed the dual properties of reducing tumor growth/metastases and eliciting an immunostimulatory TME in syngeneic orthotopic lung, pancreas and colon tumor models. Clinically, high plasma level or intratumoral expression of CHI3L1 correlated with poor survival in 161 lung cancer, 155 pancreatic cancer and 180 colon cancer patients. Conclusions: These results provide the first evidence that Rab37 mediates CHI3L1 secretion in immune cells and highlight nCHI3L1 Abs that can simultaneously target both cancer cells and tumor microenvironment.

Research paper thumbnail of Characterization of a multiple epigenetic marker panel for lung cancer detection and risk assessment in plasma

Cancer, 2007

BACKGROUND. Methylation patterns may be useful biomarkers of cancer detection and risk assessment... more BACKGROUND. Methylation patterns may be useful biomarkers of cancer detection and risk assessment. METHODS. The methylation status of 6 genes, including a candidate tumor suppressor gene (BLU), the cadherin 13 gene (CDH13), the fragile histidine triad gene (FHIT), the cell cycle control gene p16, the retinoic acid receptor b gene (RARb), and the Ras association domain family 1 gene (RASSF1A), was examined in plasma samples, corresponding tumor tissues, and normal lung tissues from a group of 63 patients with lung cancer and in plasma samples from 36 cancer-free individuals. The detection rate of the p16 gene was validated in a test group of 20 patients with lung cancer. RESULTS. The concordance of methylation in tumor tissues and plasma samples was 86%, 87%, 80%, 75%, 76%, and 84% for the BLU, CDH13, FHIT, p16, RARb, and RASSF1A genes, respectively. The test group showed a similar concordance for p16 methylation detection. Multiple logistic regression analysis showed that the odds ratio for having lung cancer was 10.204 for individuals with p16 methylation (P 5 .013) and 9.952 for individuals with RASSFIA methylation (P 5 .019). After several trial tests, the authors established that methylation for 2 of the 6 markers met the criterion for an elevated risk of cancer. Comparisons yielded a sensitivity of 73%, a specificity of 82%, and a concordance of 75% between the methylation patterns in tumor tissues and in corresponding plasma samples. The detection rate was relatively high in cigarette smokers with advanced squamous cell lung cancer. CONCLUSIONS. The current results indicated that multiple epigenetic markers in the plasma, especially the p16 and RASSF1A genes, can be used for lung cancer detection. This methylation marker panel should improve the detection of cancer or the risk assessment for lung cancer in combination with conventional diagnostic tools.

Research paper thumbnail of Rab37 mediates trafficking and membrane presentation of PD-1 to sustain T cell exhaustion in lung cancer

Journal of biomedical science, Feb 7, 2024

Background Programmed cell death protein 1 (PD-1) is an immune checkpoint receptor expressed on t... more Background Programmed cell death protein 1 (PD-1) is an immune checkpoint receptor expressed on the surface of T cells. High expression of PD-1 leads to T-cell dysfunction in the tumor microenvironment (TME). However, the mechanism of intracellular trafficking and plasma membrane presentation of PD-1 remains unclear. Methods Multiple databases of lung cancer patients were integratively analyzed to screen Rab proteins and potential immune-related signaling pathways. Imaging and various biochemical assays were performed in Jurkat T cells, splenocytes, and human peripheral blood mononuclear cells (PBMCs). Rab37 knockout mice and specimens of lung cancer patients were used to validate the concept. Results Here, we identify novel mechanisms of intracellular trafficking and plasma membrane presentation of PD-1 mediated by Rab37 small GTPase to sustain T cell exhaustion, thereby leading to poor patient outcome. PD-1 colocalized with Rab37-specific vesicles of T cells in a GTP-dependent manner whereby Rab37 mediated dynamic trafficking and membrane presentation of PD-1. However, glycosylation mutant PD-1 delayed cargo recruitment to the Rab37 vesicles, thus stalling membrane presentation. Notably, T cell proliferation and activity were upregulated in tumorinfiltrating T cells from the tumor-bearing Rab37 knockout mice compared to those from wild type. Clinically, the multiplex immunofluorescence-immunohistochemical assay indicated that patients with high Rab37 + /PD-1 + /TIM3 + / CD8 + tumor infiltrating T cell profile correlated with advanced tumor stages and poor overall survival. Moreover, human PBMCs from patients demonstrated high expression of Rab37, which positively correlated with elevated levels of PD-1 + and TIM3 + in CD8 + T cells exhibiting reduced tumoricidal activity. Conclusions Our results provide the first evidence that Rab37 small GTPase mediates trafficking and membrane presentation of PD-1 to sustain T cell exhaustion, and the tumor promoting function of Rab37/PD-1 axis in T cells of TME in lung cancer. The expression profile of Rab37 high /PD-1 high /TIM3 high in tumor-infiltrating CD8 + T cells is a biomarker for poor prognosis in lung cancer patients.

Research paper thumbnail of Estradiol-mediated inhibition of Sp1 decreases miR-3194-5p expression to enhance CD44 expression during lung cancer progression

Journal of Biomedical Science, Jan 17, 2022

Research paper thumbnail of High-CLDN4 ESCC cells harbor stem-like properties and indicate for poor concurrent chemoradiation therapy response in esophageal squamous cell carcinoma

Therapeutic Advances in Medical Oncology, 2019

Background: Esophageal squamous cell carcinoma (ESCC) is the major type of esophageal cancer in A... more Background: Esophageal squamous cell carcinoma (ESCC) is the major type of esophageal cancer in Asia and demonstrates poor survival rates following a therapeutic regimen. Methods: Cancer stem cells (CSCs) are responsible for tumor initiation, progression, and treatment failure in cancers. Therefore, identification and characterization of CSCs may help to improve clinical outcomes for ESCC patients. Tumor sphere formation assay are performed to isolate cancer stem-like ESCC cells. QRT-PCR, tumor initiation, metastasis, CCRT treatment are used to evaluate ESCC cells’ stemness properties in vitro and in vivo. Results: The authors’ data demonstrates that cancer stem-like ESCC cells harbored stemness characteristics including self-renewal, differentiation, and transdifferentiation, and possess tumor initiation, metastasis, and treatment inefficiency properties. For the identification of useful biomarkers of cancer stem-like ESCC cells, the authors further identified that CLDN4 was upregu...

Research paper thumbnail of IL-33/NF-κB/ST2L/Rab37 positive-feedback loop promotes M2 macrophage to limit chemotherapeutic efficacy in lung cancer

Cell death and disease, May 22, 2024

Research paper thumbnail of Dysregulation of SOX17/NRF2 axis confers chemoradiotherapy resistance and emerges as a novel therapeutic target in esophageal squamous cell carcinoma

Journal of Biomedical Science

Background Esophageal squamous cell carcinoma (ESCC) is the sixth leading cause of cancer-associa... more Background Esophageal squamous cell carcinoma (ESCC) is the sixth leading cause of cancer-associated death worldwide with a dismal overall 5-year survival rate of less than 20%. The standard first-line therapy for advanced ESCC is concomitant chemo-radiation therapy (CCRT); however, patients usually develop resistance, resulting in unfavorable outcomes. Therefore, it is urgent to identify the mechanisms underlying CCRT resistance and develop effective treatment strategies. Methods Patients’ endoscopic biopsy tumor tissues obtained before CCRT treatment were used to perform RNA-seq and GSEA analysis. Immunohistochemical (IHC) staining, chromatin immunoprecipitation (ChIP), and promoter reporter analyses were conducted to investigate the relationship between SOX17 and NRF2. Xenograft mouse models were used to study the role of SOX17/NRF2 axis in tumor growth and the efficacy of carboxymethyl cellulose-coated zero-valent-iron (ZVI@CMC). Results In this study, a notable gene expression ...

Research paper thumbnail of YAP1 acts as a negative regulator of pro-tumor TAZ expression in esophageal squamous cell carcinoma

Cellular Oncology

Purpose Although YAP1 and TAZ are believed to be equivalent downstream effectors of the Hippo pat... more Purpose Although YAP1 and TAZ are believed to be equivalent downstream effectors of the Hippo pathway, differential expression of YAP1 or TAZ suggests distinct functions during cancer progression. The exact role of YAP1 and TAZ in esophageal cancer, the 6th leading cancer-related mortality in the world, remains elusive. Methods Following single or double manipulation of YAP1 or TAZ expression, we subjected these manipulated cells to proliferation, migration, invasion, and xenograft tumorigenesis assays. We used RT-qPCR and Western blotting to examine their expression in the manipulated cells with or without inhibition of transcription or translation. We also examined the impact of YAP1 or TAZ deregulation on clinical outcome of esophageal cancer patients from the TCGA database. Results We found that YAP1 functions as a tumor suppressor whereas TAZ exerts pro-tumor functions in esophageal cancer cells. We also found a significant increase in TAZ mRNA expression upon YAP1 depletion, b...

Research paper thumbnail of Epigenetic silencing of AATK in acinar to ductal metaplasia in murine model of pancreatic cancer

Clinical Epigenetics, 2020

Background Cancer subtype switching, which involves unclear cancer cell origin, cell fate decisio... more Background Cancer subtype switching, which involves unclear cancer cell origin, cell fate decision, and transdifferentiation of cells within a confined tumor microenvironment, remains a major problem in pancreatic cancer (PDA). Results By analyzing PDA subtypes in The Cancer Genome Atlas, we identified that epigenetic silencing of apoptosis-associated tyrosine kinase (AATK) inversely was correlated with mRNA expression and was enriched in the quasi-mesenchymal cancer subtype. By comparing early mouse pancreatic lesions, the non-invasive regions showed AATK co-expression in cells with acinar-to-ductal metaplasia, nuclear VAV1 localization, and cell cycle suppression; but the invasive lesions conversely revealed diminished AATK expression in those with poorly differentiated histology, cytosolic VAV1 localization, and co-expression of p63 and HNF1α. Transiently activated AATK initiates acinar differentiation into a ductal cell fate to establish apical-basal polarization in acinar-to-du...

Research paper thumbnail of Annexin A2 Silencing Induces G2 Arrest of Non-small Cell Lung Cancer Cells through p53-dependent and -independent Mechanisms

Journal of Biological Chemistry, 2012

Background: Aberrant expression of annexin A2 has been found in several cancers; however, its rol... more Background: Aberrant expression of annexin A2 has been found in several cancers; however, its role in tumorigenesis is unknown. Results: Silencing annexin A2 partly caused p53-regulated cell cycle arrest at the G 2 phase by inactivating JNK/c-Jun signaling. Conclusion: Annexin A2 promotes the cell cycle and cell proliferation in lung cancer in part by inhibiting p53. Significance: This study provides new insight into the tumorigenic role of annexin A2. Annexin A2 (ANXA2) overexpression is required for cancer cell proliferation; however, the molecular mechanisms underlying ANXA2-mediated regulation of the cell cycle are still unknown. ANXA2 is highly expressed in non-small cell lung cancer (NSCLC) and is positively correlated with a poor prognosis. NSCLC A549 cells lacking ANXA2 exhibited defects in tumor growth in vivo and in cell proliferation in vitro without cytotoxicity. ANXA2 knockdown induced cell cycle arrest at G 2 phase. Unexpectedly, ANXA2 silencing increased the expression of p53 and its downstream genes, which resulted in p53-dependent and-independent G 2 arrest. Aberrant JNK inactivation, which was observed in ANXA2-deficient cells, inhibited cell proliferation following G 2 arrest. A lack of ANXA2 caused a loss of JNK-regulated c-Jun expression, resulting in an increase in p53 transcription. These results demonstrate a novel role for ANXA2 in NSCLC cell proliferation by facilitating the cell cycle partly through the regulation of p53 via JNK/c-Jun.

Research paper thumbnail of Secretory autophagy promotes Rab37-mediated exocytosis of tissue inhibitor of metalloproteinase 1

Journal of Biomedical Science

Background Rab37-mediated exocytosis of tissue inhibitor of metalloproteinase 1 (TIMP1), an infla... more Background Rab37-mediated exocytosis of tissue inhibitor of metalloproteinase 1 (TIMP1), an inflammatory cytokine, under serum-depleted conditions which leads to suppression of lung cancer cell metastasis has been reported. Starvation is also a stimulus of autophagic activity. Herein, we reveal that starvation activates Rab37 and induces autophagy. Methods We used an overexpression/knockdown system to determine the relationship between autophagy and Rab37 in vitro and in vivo. The autophagy activity was detected by immunoblotting, transmission electron microscope, autophagosome purification, and immunofluorescence under the confocal microscope. Lung-to-lung metastasis mouse model was used to clarify the role of autophagy and Rab37 in lung cancer. Clinical lung cancer patient specimens and an online big database were analyzed. Results Initially, we demonstrated that active-form Rab37 increased LC3-II protein level (the marker of autophagosome) and TIMP1 secretion. Accordingly, silenc...

Research paper thumbnail of Application of Array-Based Epigenomic Technology for the Identification of Hypermethylated CpG Site in Lung Cancer Patients

Cancer is caused by the accumulation of both genetic and epigenetic changes. Promoter hypermethyl... more Cancer is caused by the accumulation of both genetic and epigenetic changes. Promoter hypermethylation is one of the major epigenetic changes that cause gene inactivation. Aberrant promoter hypermethylation of CpG islands associated with tumor suppressor genes (TSGs) can lead to transcriptional silencing and result in tumorigenesis. The genomic regions with hypermethylation status may possess novel candidate TSGs. We used a microarray-based epigenome-wide methylation analysis called differential methylation hybridization (DMH) to identify the regions of hypermethylation and a chromatin immunoprecipitation (ChIP)-on-chip analysis to identify the regions of condensed or open chromatin in 20 non-small cell lung cancer (NSCLC) patients and several lung cell lines, and have successfully detected several cancer subtype- and stage-specific hypermethylated genes. They may serve as biomarkers for the early detection or prognosis prediction of lung cancer. Using DMH, we identified promoter hy...

Research paper thumbnail of AKT-mediated phosphorylation enhances protein stability and transcription activity of ZNF322A to promote lung cancer progression

Oncogene, 2019

ZNF322A is an oncogenic zinc-finger transcription factor. Our published results show that ZNF322A... more ZNF322A is an oncogenic zinc-finger transcription factor. Our published results show that ZNF322A positively regulates transcription of alpha-adducin (ADD1) and cyclin D1 (CCND1) to promote tumorgenicity of lung cancer. However, the upstream regulatory mechanisms of ZNF322A protein function remain elusive. Here, we demonstrate that AKT could phosphorylate ZNF322A by in vitro kinase assay and cell-based mass spectrometry analysis. Overexpression of AKT promoted ZNF322A protein stability and transcriptional activity, whereas these effects were inhibited by knockdown of AKT or treating with AKT inhibitor. We studied AKT-mediated phosphorylation sites, viz. Thr-150, Ser-224, Thr-234, and Thr-262. ZNF322A phosphorylation at Thr-262 by AKT promoted ZNF322A protein stability thus increased ADD1 promoter activity. Interestingly, phosphorylation at Thr-150, Ser-224, and Thr-234 enhanced transcription activity without affecting protein stability of ZNF322A. Chromatin immunoprecipitation and DNA affinity precipitation assays showed that ZNF322A phosphorylation defective mutants Thr-150A, Ser-224A, and Thr-234A attenuated chromatin binding and DNA binding affinity to ADD1 and CCND1 promoters compared with wild-type ZNF322A. Furthermore, AKT-mediated Thr-150, Ser-224, Thr-234, and Thr-262 phosphorylation promoted lung cancer cell growth and metastasis in vitro and in vivo. Clinically, expression of phosphorylated ZNF322A (p-ZNF) correlated with actively phosphorylated AKT (p-AKT) in tumor specimens from 150 lung cancer patients. Multivariate Cox regression analysis indicated that combined p-AKT and p-ZNF expression profile was an independent factor to predict the clinical outcome in lung cancer patients. Our results reveal a new mechanism of AKT signaling in promoting ZNF322A protein stability and transcriptional activity in lung cancer cell, xenograft, and clinical models.

Research paper thumbnail of CK1δ/GSK3β/FBXW7α axis promotes degradation of the ZNF322A oncoprotein to suppress lung cancer progression

Oncogene, Oct 5, 2017

Overexpression of Cys2His2 zinc-finger 322A (ZNF322A) oncogenic transcription factor is associate... more Overexpression of Cys2His2 zinc-finger 322A (ZNF322A) oncogenic transcription factor is associated with lung tumorigenesis. However, the mechanism of ZNF322A overexpression remains poorly understood. Here, we discover that protein stability of ZNF322A is regulated by coordinated phosphorylation and ubiquitination through the CK1δ/GSK3β/FBXW7α axis. CK1δ and GSK3β kinases sequentially phosphorylate ZNF322A at serine-396 and then serine-391. Moreover, the doubly phosphorylated ZNF322A protein creates a destruction motif for the ubiquitin ligase FBXW7α leading to ZNF322A protein destruction. Overexpression of FBXW7α induces ZNF322A protein degradation, thereby blocks ZNF322A transcription activity and suppresses ZNF322A-induced tumor growth and metastasis in vitro and in vivo. Clinically, overexpression of ZNF322A correlates with low FBXW7α or defective CK1δ/GSK3β-mediated phosphorylation in lung cancer patients. Multivariate Cox regression analysis indicates that patients with ZNF322A...

Research paper thumbnail of A 3D-QSAR Study of Celebrex-Based Pdk1 Inhibitors Using Comfa Method

Journal of the Chinese Chemical Society, 2009

A 3D-QSAR study of celebrex-based compounds of PDK1 inhibitors using comparative molecular field ... more A 3D-QSAR study of celebrex-based compounds of PDK1 inhibitors using comparative molecular field analysis (CoMFA) was carried out. The structures of the compounds were obtained using quantum chemistry calculation. CoMFA calculations for a number of grouped subsets of ...

Research paper thumbnail of Pin1 positively affects tumorigenesis of esophageal squamous cell carcinoma and correlates with poor survival of patients

Journal of Biomedical Science, 2014

Background: Pin1 promotes oncogenesis by regulating multiple oncogenic signaling. In this study, ... more Background: Pin1 promotes oncogenesis by regulating multiple oncogenic signaling. In this study, we investigated the involvement of Pin1 in tumor progression and in the prognosis of human esophageal squamous cell carcinoma (ESCC). Results: We observed that proliferation, clonogenicity and tumorigenesis of CE81T cells were inhibited by Pin1 knockdown. We next analyzed Pin1 expression in clinical ESCC specimens. When compared to the corresponding non-tumor part, Pin1 protein and mRNA levels in tumor part were higher in 84% and 62% patients, respectively. By immunohistochemistry, we identified that high Pin1 expression was associated with higher primary tumor stage (p = 0.035), higher overall cancer stage (p = 0.047) and poor overall survival (p < 0.001). Furthermore, the association between expression of Pin1 and levels of β-catenin and cyclin D in cell line and clinical specimens was evaluated. β-catenin and cyclin D1 were decreased in CE81T cells with Pin1 knockdown. Cyclin D1 level correlated with Pin1 expression in clinical ESCC specimens. Conclusions: Pin1 upregulation was associated with advanced stage and poor prognosis of ESCC. Pin1 knockdown inhibited aggressiveness of ESCC cells. β-catenin and cyclin D1 were positively regulated by Pin1. These results indicated that targeting Pin1 pathway could represent a potential modality for treating ESCC.

Research paper thumbnail of Molecular Diagnostic Markers for Lung Cancer in Sputum and Plasma

Annals of the New York Academy of Sciences, 2006

Lung cancer is the leading cause of cancer deaths worldwide. This study was designed to select mu... more Lung cancer is the leading cause of cancer deaths worldwide. This study was designed to select multiple DNA markers, which have high sensitivity and specificity to serve as biomarkers for diagnosis of lung cancer. We examined the promoter hypermethylation of three tumor suppressor genes by methylation-specific PCR (MSP), and the instability of eight microsatellite markers by loss of heterozygosity (LOH) and microsatellite instability (MSI) analyses in lung tumor tissues and matched sputum specimens from 79 lung cancer patients. On the basis of the results of sensitivity, specificity, and concordance from each marker analyzed, we selected seven biomarkers, which are LOH of D9S286, D9S942, GATA49D12, and D13S170, MSI of D9S942, and methylation of p16 INK4a and RAR␤, from the sputum analyses. These selected etiologically associated biomarkers can potentially be used as supplemental diagnostic biomarkers for early lung cancer detection.

Research paper thumbnail of Global Oct4 target gene analysis reveals novel downstream PTEN and TNC genes required for drug-resistance and metastasis in lung cancer

Nucleic acids research, Jan 18, 2015

Overexpression of Oct4, a stemness gene encoding a transcription factor, has been reported in sev... more Overexpression of Oct4, a stemness gene encoding a transcription factor, has been reported in several cancers. However, the mechanism by which Oct4 directs transcriptional program that leads to somatic cancer progression remains unclear. In this study, we provide mechanistic insight into Oct4-driven transcriptional network promoting drug-resistance and metastasis in lung cancer cell, animal and clinical studies. Through an integrative approach combining our Oct4 chromatin-immunoprecipitation sequencing and ENCODE datasets, we identified the genome-wide binding regions of Oct4 in lung cancer at promoter and enhancer of numerous genes involved in critical pathways which promote tumorigenesis. Notably, PTEN and TNC were previously undefined targets of Oct4. In addition, novel Oct4-binding motifs were found to overlap with DNA elements for Sp1 transcription factor. We provided evidence that Oct4 suppressed PTEN in an Sp1-dependent manner by recruitment of HDAC1/2, leading to activation ...

Research paper thumbnail of Recent advances in conventional and unconventional vesicular secretion pathways in the tumor microenvironment

Journal of Biomedical Science

All cells in the changing tumor microenvironment (TME) need a class of checkpoints to regulate th... more All cells in the changing tumor microenvironment (TME) need a class of checkpoints to regulate the balance among exocytosis, endocytosis, recycling and degradation. The vesicular trafficking and secretion pathways regulated by the small Rab GTPases and their effectors convey cell growth and migration signals and function as meditators of intercellular communication and molecular transfer. Recent advances suggest that Rab proteins govern conventional and unconventional vesicular secretion pathways by trafficking widely diverse cargoes and substrates in remodeling TME. The mechanisms underlying the regulation of conventional and unconventional vesicular secretion pathways, their action modes and impacts on the cancer and stromal cells have been the focus of much attention for the past two decades. In this review, we discuss the current understanding of vesicular secretion pathways in TME. We begin with an overview of the structure, regulation, substrate recognition and subcellular loc...

Research paper thumbnail of Functional EGFR Germline Polymorphisms May Confer Risk for EGFR Somatic Mutations in Non–Small Cell Lung Cancer, with a Predominant Effect on Exon 19 Microdeletions

Cancer Research, 2011

Somatic mutations in the EGFR tyrosine kinase domain play a critical role in the development and ... more Somatic mutations in the EGFR tyrosine kinase domain play a critical role in the development and treatment of non–small cell lung cancer (NSCLC). Strong genetic influence on susceptibility to these mutations has been suggested. To identify the genetic factors conferring risk for the EGFR tyrosine kinase mutations in NSCLC, a case–control study was conducted in 141 Taiwanese NSCLC patients by focusing on three functional polymorphisms in the EGFR gene [−216G/T, intron 1 (CA)n, and R497K]. Allelic imbalance of the EGFR −216G/T polymorphism was also tested in the heterozygous patients and in the NCI-60 cancer cell lines to further verify its function. We found that the frequencies of the alleles −216T and CA-19 are significantly higher in the patients with any mutation (P = 0.032 and 0.01, respectively), in particular in those with exon 19 microdeletions (P = 0.006 and 0.033, respectively), but not in the patients with L858R mutation. The −216T allele is favored to be amplified in both...

Research paper thumbnail of Targeting protumor factor chitinase-3-like-1 secreted by Rab37 vesicles for cancer immunotherapy

Theranostics, 2022

Background: Chitinase 3-like-1 (CHI3L1) is a secretion glycoprotein associated with the immunosup... more Background: Chitinase 3-like-1 (CHI3L1) is a secretion glycoprotein associated with the immunosuppressive tumor microenvironment (TME). The secretory mode of CHI3L1 makes it a promising target for cancer treatment. We have previously reported that Rab37 small GTPase mediates secretion of IL-6 in macrophages to promote cancer progression, whereas the roles of Rab37 in the intracellular trafficking and exocytosis of CHI3L1 are unclear. Methods: We examined the concentration of CHI3L1 in the culture medium of splenocytes and bone marrow derived macrophages (BMDMs) from wild-type or Rab37 knockout mice, and macrophage or T cell lines expressing wild type, active GTP-bound or inactive GDP-bound Rab37. Vesicle isolation, total internal reflection fluorescence microscopy, and real-time confocal microscopy were conducted. We developed polyclonal neutralizing-CHI3L1 antibodies (nCHI3L1 Abs) to validate the therapeutic efficacy in orthotopic lung, pancreas and colon cancer allograft models. Multiplex fluorescence immunohistochemistry was performed to detect the protein level of Rab37 and CHI3L1, and localization of the tumor-infiltrating immune cells in allografts from mice or tumor specimens from cancer patients. Results: We demonstrate a novel secretion mode of CHI3L1 mediated by the small GTPase Rab37 in T cells and macrophages. Rab37 mediated CHI3L1 intracellular vesicle trafficking and exocytosis in a GTP-dependent manner, which is abolished in the splenocytes and BMDMs from Rab37 knockout mice and attenuated in macrophage or T cell lines expressing the inactive Rab37. The secreted CHI3L1 activated AKT, ß-catenin and NF-κB signal pathways in cancer cells and macrophages to foster a protumor TME characterized by activating M2 macrophages and increasing the population of regulatory T cells. Our developed nCHI3L1 Abs showed the dual properties of reducing tumor growth/metastases and eliciting an immunostimulatory TME in syngeneic orthotopic lung, pancreas and colon tumor models. Clinically, high plasma level or intratumoral expression of CHI3L1 correlated with poor survival in 161 lung cancer, 155 pancreatic cancer and 180 colon cancer patients. Conclusions: These results provide the first evidence that Rab37 mediates CHI3L1 secretion in immune cells and highlight nCHI3L1 Abs that can simultaneously target both cancer cells and tumor microenvironment.

Research paper thumbnail of Characterization of a multiple epigenetic marker panel for lung cancer detection and risk assessment in plasma

Cancer, 2007

BACKGROUND. Methylation patterns may be useful biomarkers of cancer detection and risk assessment... more BACKGROUND. Methylation patterns may be useful biomarkers of cancer detection and risk assessment. METHODS. The methylation status of 6 genes, including a candidate tumor suppressor gene (BLU), the cadherin 13 gene (CDH13), the fragile histidine triad gene (FHIT), the cell cycle control gene p16, the retinoic acid receptor b gene (RARb), and the Ras association domain family 1 gene (RASSF1A), was examined in plasma samples, corresponding tumor tissues, and normal lung tissues from a group of 63 patients with lung cancer and in plasma samples from 36 cancer-free individuals. The detection rate of the p16 gene was validated in a test group of 20 patients with lung cancer. RESULTS. The concordance of methylation in tumor tissues and plasma samples was 86%, 87%, 80%, 75%, 76%, and 84% for the BLU, CDH13, FHIT, p16, RARb, and RASSF1A genes, respectively. The test group showed a similar concordance for p16 methylation detection. Multiple logistic regression analysis showed that the odds ratio for having lung cancer was 10.204 for individuals with p16 methylation (P 5 .013) and 9.952 for individuals with RASSFIA methylation (P 5 .019). After several trial tests, the authors established that methylation for 2 of the 6 markers met the criterion for an elevated risk of cancer. Comparisons yielded a sensitivity of 73%, a specificity of 82%, and a concordance of 75% between the methylation patterns in tumor tissues and in corresponding plasma samples. The detection rate was relatively high in cigarette smokers with advanced squamous cell lung cancer. CONCLUSIONS. The current results indicated that multiple epigenetic markers in the plasma, especially the p16 and RASSF1A genes, can be used for lung cancer detection. This methylation marker panel should improve the detection of cancer or the risk assessment for lung cancer in combination with conventional diagnostic tools.