Shi-Long Lu | University of Colorado Denver (original) (raw)

Papers by Shi-Long Lu

Journal of Cell Communication and Signaling, 2020

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with poor pr... more Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with poor prognosis. Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor and emerging evidence shows it is associated with tumor initiation and promotion. However, the relationship between AHR and ESCC is not clear and it is meaningful to explore whether AHR could be a therapeutic target. In the present study, immunohistochemistry was performed to determine AHR expression levels in ESCC tissues. Knockdown of AHR expression in ESCC cell lines genetically and modulation of AHR by 3, 3′-diindolylmethane (DIM) pharmacologically both in vitro and in vivo were utilized to examine the corresponding alterations in cell growth, migration and invasion. Our study indicated that AHR expression levels were elevated in ESCC and associated with poor prognosis. Both knockdown and modulation of AHR inhibited tumor progression through down-regulating expression levels of PCNA, Bcl-2, Cyclin D1, MMP1, MMP2, MMP9 and up-regulating expression levels of Bax, Cleaved-Caspase 3. Our findings also indicated that repressing COX2/PGE 2 /STAT3 axis exerted inhibitory effects on ESCC both in vitro and in vivo assays. Taken together, AHR plays the key role in ESCC progression and targeting AHR as a therapeutic strategy with DIM is deserved for further exploration.

Otolaryngology - Head and Neck Surgery, 2007

tively. The difference between nonviable cells of CSE-treated (.1% and .01%) and NI-control at 1 ... more tively. The difference between nonviable cells of CSE-treated (.1% and .01%) and NI-control at 1 month was 36.36% and 14.18% and at 6 months, .68% and .25%, respectively. The net MMP decrease after valinomycin treatment of CSE-treated .1%, .01%, SI-control compared to baseline was 61.21%, 55.01%, 73.44% at 1 month and 6.74%, 16.21%, 15.93 at 6 months. Valinomycin treatment of CSE-treated (.1% and .01%) cells at 1 month and 6 months showed a reduced apoptotic response over time; after 6 months the percentage of viable cells increased to 89.64% and 46.93% (NI-control 83.79%). Staurosporine treatment of chronically CSE treated cells also confirmed loss of apoptotic response in comparison to normal, untreated cells. CONCLUSION: Chronic CSE exposure in OKF6 cells induces mitochondrial dysfunction and ongoing chronic depolarization accompanied by resistance to depolarization-induced apoptosis and other apoptotic agents. Cells cultured in the presence of aerosolized-CSE undergo changes similar to directly exposed cells. SIGNIFICANCE: An in vitro model can be used to study primary and secondhand chronic cigarette smoke exposure and resulting functional apoptotic alterations induced by these exposures. SUPPORT: Support provided in part by: FAMRI-Flight Attendant Medical Research Institute 2005 Clinical Innovator Award to Joseph A. Califano grant #M060569 and Otolaryngology Resident NIH training grant #T32DC00027.

Frontiers in Cellular and Infection Microbiology

Otitis media (OM), defined as infection or inflammation of the middle ear (ME), remains a major p... more Otitis media (OM), defined as infection or inflammation of the middle ear (ME), remains a major public health problem worldwide. Cholesteatoma is a non-cancerous, cyst-like lesion in the ME that may be acquired due to chronic OM and cause disabling complications. Surgery is required for treatment, with high rates of recurrence. Current antibiotic treatments have been largely targeted to previous culturable bacteria, which may lead to antibiotic resistance or treatment failures. For this study, our goal was to determine the microbiota of cholesteatoma tissue in comparison with other ME tissues in patients with long-standing chronic OM. ME samples including cholesteatoma, granulation tissue, ME mucosa and discharge were collected from patients undergoing tympanomastoidectomy surgery for chronic OM. Bacteria were profiled by 16S rRNA gene sequencing in 103 ME samples from 53 patients. Respiratory viruses were also screened in 115 specimens from 45 patients. Differences in bacterial pro...

Oncogene, 2022

Recent studies have reported dysbiotic oral microbiota and tumor-resident bacteria in human head ... more Recent studies have reported dysbiotic oral microbiota and tumor-resident bacteria in human head and neck squamous cell carcinoma (HNSCC). We aimed to identify and validate oral microbial signatures in treatment-naïve HNSCC patients compared with healthy control subjects. We confirm earlier reports that the relative abundances of Lactobacillus spp. and Neisseria spp. are elevated and diminished, respectively, in human HNSCC. In parallel, we examined the diseasemodifying effects of microbiota in HNSCC, through both antibiotic depletion of microbiota in an induced HNSCC mouse model (4-Nitroquinoline 1-oxide, 4NQO) and reconstitution of tumor-associated microbiota in a germ-free orthotopic mouse model. We demonstrate that depletion of microbiota delays oral tumorigenesis, while microbiota transfer from mice with oral cancer accelerates tumorigenesis. Enrichment of Lactobacillus spp. was also observed in murine Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the

Cell, 2007

Inhibition of protein phosphatase 2A (PP2A) activity has been identified as a prerequisite for th... more Inhibition of protein phosphatase 2A (PP2A) activity has been identified as a prerequisite for the transformation of human cells. However, the molecular mechanisms by which PP2A activity is inhibited in human cancers are currently unclear. In this study, we describe a cellular inhibitor of PP2A with oncogenic activity. The protein, designated Cancerous Inhibitor of PP2A (CIP2A), interacts directly with the oncogenic transcription factor c-Myc, inhibits PP2A activity toward c-Myc serine 62 (S62), and thereby prevents c-Myc proteolytic degradation. In addition to its function in c-Myc stabilization, CIP2A promotes anchorageindependent cell growth and in vivo tumor formation. The oncogenic activity of CIP2A is demonstrated by transformation of human cells by overexpression of CIP2A. Importantly, CIP2A is overexpressed in two common human malignancies, head and neck squamous cell carcinoma (HNSCC) and colon cancer. Thus, our data show that CIP2A is a human oncoprotein that inhibits PP2A and stabilizes c-Myc in human malignancies.

ABSTRACTThere is an urgent need of having a rapid, high throughput, yet accurate SARS-COV-2 PCR t... more ABSTRACTThere is an urgent need of having a rapid, high throughput, yet accurate SARS-COV-2 PCR testing to control the COVID19 pandemic. However, the RNA extraction step in conventional PCR creates a major bottle neck in the diagnostic process. In this paper we modified the CDC COVID-19 assay and developed an RNA-extraction free RT-qPCR assay for SARS-CoV-2, i.e. COVIDFast™. Depending on sample types, the assay is further divided into SwabFAST™, which uses anterior nares nasal swab, and SalivaFAST™, which uses saliva. By utilizing the proprietary buffer for either swab or saliva samples, the performance of SwabFAST or SalivaFAST is equivalent to RNA-extraction SARS-CoV-2 RT-qPCR in both contrived and clinical samples. The limit of detection of either assay is 4 copies/μL. We further developed a semi-automatic system, which is easy to adapt by clinical lab for implementation of a high-throughput SARS-CoV-2 test. Working together with the COVIDCheck Colorado, we have tested over 400,0...

Table S1. Relative methylation levels of mgmiRs in human HNSCC cell lines and normal head and nec... more Table S1. Relative methylation levels of mgmiRs in human HNSCC cell lines and normal head and neck cell lines. Table S2. Relative methylation level in tissues from 189 HNSCC patients and 92 normal controls. Table S3. Univariate and multivariable logistic regression with continuous variables in tissues. Table S4. Relative methylation level in saliva from 86 HNSCC patients and 108 normal controls. Table S5. Univariate and multivariable logistic regression with continuous variables in saliva. (DOCX 42Â kb)

Open Forum Infectious Diseases

Background SARS-CoV-2 variants of concern (VOC) have challenged real-time reverse transcriptase p... more Background SARS-CoV-2 variants of concern (VOC) have challenged real-time reverse transcriptase polymerase chain reaction (RT-PCR) methods for the diagnosis of COVID-19. Methods The CDC 2019-Novel Coronavirus real-time RT-PCR panel was modified to create a single-plex extraction-free proxy RT-PCR assay, VOCFast™. This assay uses the nucleocapsid N1 as well as novel primer/probe pairs to target VOC mutations in the Orf1a and spike (S) genes. For analytical validation of VOCFast, synthetic controls for the Wuhan, alpha/B.1.1.7, beta/B.1.351, and gamma/P.1 strains were tested at various concentrations. Clinical validation was performed using patient anterior nares swab and saliva specimens collected in the Denver, CO area between Nov 2020 and Feb 2021 or in March 2021. Orthogonal next-generation sequencing (NGS) was also performed. Results Similar N1 quantification cycle (Cq) values corresponding to viral load were observed for all strains, suggesting that VOC mutations do not affect p...

Journal of Investigative Medicine

Purpose of Study Transforming growth factor β (TGF-β) has roles in both tumor suppression and pro... more Purpose of Study Transforming growth factor β (TGF-β) has roles in both tumor suppression and promotion. Although Smad2 and Smad3 are TGF-β signaling mediators, their functions in mediating TGF-β signaling during cancer development remain to be determined. We have examined expression patterns of Smad2 and Smad3 in human skin SCCs and found that over 95% of tumor samples retain Smad3, whereas 70% of SCCs have lost the Smad2 protein. Previously, we have shown that Smad3 knockout mice are resistant to skin carcinogenesis due to abrogation of TGF-β-mediated tumor promotion effect. Methods Used In the current study, we assessed the role of Smad2 in skin carcinogenesis by generating mice with keratinocyte-specific Smad2 deletion. Summary of Results Although conditional Smad2 knockout mice did not develop spontaneous skin tumors, when exposed to a two-stage chemical carcinogenesis protocol, they exhibited accelerated tumor formation and malignant progression compared with wild-type mice. Smad2−/− tumors were more poorly differentiated in comparison with tumors from wild-type mice. At the papilloma stage, Smad2−/− tumors exhibited molecular alterations usually associated with late-stage SCC progression and epithelial-mesenchymal transition (EMT), eg, a significant elevation of keratin K8, snail, twist, tenascin C and vimentin. Additionally, Smad2−/− tumors displayed HGF-dependent vessel growth culminating in approximately three times the angiogenesis seen in Smad2+/+ tumors. Since these molecules are documented or potential TGF-β target genes, we examined TGF-β1 levels in Smad2−/− tumors. We found that neither the TGF-β1 level nor Smad3 activation was elevated in Smad2−/− tumors. Conclusions Reached Thus, our study suggests that Smad2 loss results in the elevation of tumor invasion-associated and angiogenesis genes via a TGF-β-independent mechanism.

Cancer Research, 2013

Head and neck squamous cell carcinoma (HNSCC) patients have a poor prognosis and invasion and met... more Head and neck squamous cell carcinoma (HNSCC) patients have a poor prognosis and invasion and metastasis are the major causes of mortality. However, the molecular mechanisms of HNSCC invasion and metastasis remain obscure. The phosphatidylinositol 3-kinase (PI3K) pathway regulates a wide range of cellular processes crucial for tumorigenesis. Amplification and mutation of PIK3CA, the gene coding for the catalytic subunit of PI3K, are among the most common genetic alterations in human HNSCC. To delineate the in vivo roles of PIK3CA during head and neck tumorigenesis, we developed a PIK3CA genetically engineered mouse model (GEMM), in which PIK3CA overexpression is specifically induced in the head and neck epithelia. While overexpression of PIK3CA alone resulted in epithelial hyperplasia, and carcinoma in situ, it was not sufficient to induce visible tumor formation. In contrast, when we applied 4NQO, a DNA adduct-forming agent widely used as a tobacco surrogate together with PIK3CA overexpression, the PIK3CA-GEMM developed ∼50% poorly differentiated HNSCC compared to ∼10% of those in the control mice. PIK3CA tumors also had increased numbers of infiltrated leukocytes and angiogenesis. In addition, either regional lymph node metastases or lung metastases was observed in ∼40% of the PIK3CA-GEMM compared to no metastases in control mice. Characterizations of PIK3CA tumors revealed that PIK3CA tumors underwent epithelial and mesenchymal transition, and formed poorly differentiated metastatic tongue SCC in an orthotopical mouse model. Molecular analysis of the PIK3CA tumors suggests that rather than AKT, PDK1 facilitates progression of PI3K-driven HNSCC, and enhanced TGFbeta signaling with increased TGFbeta1 ligand and Smad3 may further contribute to this process. Lastly, overexpression of PIK3CA is associated with HNSCC progression and metastasis, and positively correlated with PDK1 expression but negatively with AKT activation, further verified the clinical relevance of our GEMM study. In summary, our results suggest that PIK3CA oncogene drives invasion and metastasis of HNSCC through PDK1 and TGFbeta signaling, and combined targeting of these pathways will reduce tumor progression in advanced HNSCC patients with PIK3CA alterations, which comprise about ∼40% of all HNSCC patients. Citation Format: Li Du, Xi Chen, Jingping Shen, Fang Zhang, Shi-Long Lu. PIK3CA overexpression induces epithelial-mesenchymal transition and progression of head and neck squamous cell carcinonoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 334. doi:10.1158/1538-7445.AM2013-334

Oncogene

Head and neck squamous cell carcinoma (HNSCC) patients have a poor prognosis, with invasion and m... more Head and neck squamous cell carcinoma (HNSCC) patients have a poor prognosis, with invasion and metastasis as major causes of mortality. The phosphatidylinositol 3-kinase (PI3K) pathway regulates a wide range of cellular processes crucial for tumorigenesis, and PIK3CA amplification and mutation are among the most common genetic alterations in human HNSCC. Compared to the well-documented roles of the PI3K pathway in cell growth and survival, the roles of the PI3K pathway in tumor invasion and metastasis have not been well delineated. We generated a PIK3CAgenetically engineered mouse model (PIK3CA-GEMM) in which wildtype PIK3CA is overexpressed in head and neck epithelium. Although PIK3CA overexpression alone was not sufficient to initiate HNSCC formation, it significantly increased tumor susceptibility in an oralcarcinogenesis mouse model. PIK3CA overexpression in mouse oral epithelium increased tumor invasiveness and metastasis by increasing epithelial-mesenchymal transition and by enriching a cancer stem cell phenotype in tumor epithelial cells. In addition to these epithelial alterations, we also observed marked inflammation in tumor stroma. AKT is a central signaling mediator of the PI3K pathway. However, molecular analysis suggested that progression of PIK3CA-driven Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

It has been shown that Smad3 exerts both tumor-suppressive and -promoting roles. To evaluate the ... more It has been shown that Smad3 exerts both tumor-suppressive and -promoting roles. To evaluate the role of Smad3 in skin carcinogenesis in vivo, we applied a chemical skin carcinogenesis protocol to Smad3 knockout mice (Smad3 / and Smad3 / ) and wild-type littermates (Smad3 / ). Smad3 / mice exhibited reduced papilloma formation in comparison with Smad3 / mice and did not develop any squamous cell carcinomas. Further analysis revealed that Smad3 knockout mice were resistant to 12-O-tetradecanoylphorbol-13-acetate (TPA)–induced epidermal hyperproliferation. Concurrently, increased apoptosis was observed in TPAtreated Smad3 / skin and papillomas when compared with those of wild-type mice. Expression levels of activator protein-1 family members (c-jun, junB, junD, and c-fos) and transforming growth factor (TGF)were significantly lower in TPA-treated Smad3 / skin, cultured keratinocytes, and papillomas, as compared with Smad3 / controls. Smad3 / papillomas also exhibited reduced leukocyte...

Molecular carcinogenesis, 2006

The functions of transforming growth factor beta-1(TGFbeta1) are cell-context specific. We have f... more The functions of transforming growth factor beta-1(TGFbeta1) are cell-context specific. We have found that TGFbeta1 expression in human skin squamous cell carcinoma (SCC) samples has two distinct distribution patterns: (1) either predominantly in suprabasal layers or (2) throughout tumor epithelia including basal proliferative cells. To understand whether the spatial TGFbeta1 expression patterns affect its functions, we have generated several keratinocyte-specific transgenic mouse models in which TGFbeta1 overexpression can be induced either predominantly in the suprabasal epidermis or in the basal layer of the epidermis and hair follicles. Suprabasal TGFbeta1 overexpression inhibits keratinocyte proliferation, suppresses skin carcinogenesis at early stages, but promotes tumor invasion at later stages. In contrast, TGFbeta1 overexpression in the basal layer of the epidermis and hair follicles causes a severe inflammatory skin disorder and epidermal hyperproliferation. Given the impo...

Molecular Oncology, 2021

Epidermal growth factor receptor (EGFR) is often overexpressed in head and neck squamous cell car... more Epidermal growth factor receptor (EGFR) is often overexpressed in head and neck squamous cell carcinoma (HNSCC) and represents a top candidate for targeted HNSCC therapy. However, the clinical effectiveness of current Food and Drug Administration (FDA)‐approved drugs targeting EGFR is moderate, and the overall survival rate for HNSCC patients remains low. Therefore, more effective treatments are urgently needed. In this study, we generated a novel diphtheria toxin‐based bivalent human epidermal growth factor fusion toxin (bi‐EGF‐IT) to treat EGFR‐expressing HNSCC. Bi‐EGF‐IT was tested for in vitro binding affinity, cytotoxicity, and specificity using 14 human EGFR‐expressing HNSCC cell lines and three human EGFR‐negative cancer cell lines. Bi‐EGF‐IT had increased binding affinity for EGFR‐expressing HNSCC compared with the monovalent version (mono‐EGF‐IT), and both versions specifically depleted EGFR‐positive HNSCC, but not EGFR‐negative cell lines, in vitro. Bi‐EGF‐IT exhibited a c...

Otolaryngology - Head and Neck Surgery, 2006

Otolaryngology -- Head and Neck Surgery, 2013

Objectives: Early detection of head and neck squamous cell carcinoma (HNSCC) improves long-term s... more Objectives: Early detection of head and neck squamous cell carcinoma (HNSCC) improves long-term survival. More than half of patients with HNSCC present with locoregional or metastatic disease at the time of diagnosis. MicroRNAs are promising markers for early detection, as they are stable, tissue-specific, and known to be involved in processes critical for tumor development and progression. Methylated miRNA sequences have already been studied in early detection of lung and gastrointestinal (GI) cancers. Methods: Genomic DNA was extracted from 30 SCC samples, 24 samples of grossly normal adjacent mucosa from those tumor patients, and 8 samples from normal controls (no cancer). The gDNA was treated with bisulfate to identify methylation patterns, and quantitative polymerase chain reaction was run for 6 miRNA markers (9-1, 9-3, 124-1, 124-2, 124-3, 137) to determine the level of expression in each sample. Results: Overall expression of each marker was significantly higher in the tumor ...

International Journal of Radiation Oncology*Biology*Physics, 2012

GFP-positive cells, tightly adhered with pericytes, and well perfused with Hoechst 33342 dyes. Th... more GFP-positive cells, tightly adhered with pericytes, and well perfused with Hoechst 33342 dyes. These changes suggested remaining vessels are in a more mature structure and vasculogenesis is involved in their survival during F-RT. Although the combination of the EGFR inhibitor gefitinib with F-RT affected vascular structure by dissociating pericytes from vascular wall, it had no enhancement effect on tumor growth delay. This combination in fact protected tumor vessels from irradiation damage, in accord with the elevation of MVD and good vascular perfusion leading to less tumor necrosis and hypoxia. In contrast, combination of CXCR4 inhibitor AMD3100 with F-RT had a significant enhancement effect on tumor growth delay. As compared with those treated by F-RT alone, tumors treated by this combination had less infiltration of GFP-positive BM cells, lower MVD, poorer perfusion function in tumor vessels and more hypoxia; these tumor vessels were not covered by pericytes. Conclusions: Our results suggest that vasculogenesis is involved in surviving tumor vessels during fractionated radiation therapy. There are complex interactions between combination of vessel-targeting therapy with RT and enhancement effect do not always exist. However, blockage of the influx of BMDCs by CXCR4 inhibitor intervenes the vascular maturation via vasculogenesis and has an enhancement effect on RT.

Otolaryngology-Head and Neck …, 2004

Abstract Problem: In many cancer types, TGF-B signaling receptors and mediators (Smad2, Smad4) fu... more Abstract Problem: In many cancer types, TGF-B signaling receptors and mediators (Smad2, Smad4) function as tumor suppressors, whereas their antagonist (Smad7) may be elevated. Although such alterations in the individual components of the TGF-B pathway have been described in human head and neck squamous cell carcinoma (HNSCC), no studies have been conducted that analyze whether multiple synchronous alterations of this signal transduction pathway exist in HNSCC. The purpose of this study was to analyze TGF-B signaling pathway protein and mRNA expression in human HNSCC. Methods: Thirty-five tumor and matched normal mucosa pairs were analyzed with ELISA to quantify expression of the TGF-B ligand. Immunohistological staining (IHC) was used on 31 tumor/mucosa pairs to determine expression of Smad2, Smad4, and TGF-B type II receptor (BRII). Twenty-seven tumor/mucosa pairs were analyzed using quantitative reverse transcription PCR to quantitate the mRNA expression levels of Smad4 and Smad7. Results: Protein expression of Smad2 and BRII were reduced in 48.4% and 58.1% of tumors, respectively, in comparison with normal mucosa controls. TGFB-1 ligand expression was increased 1.5- to 3.78-fold in 54% of HSNCC tumors compared to controls. Smad 4 protein and mRNA expression was reduced in 74.2% and 77.8% of tumors, respectively. Smad7 expression was increased by 1.5- to 6-fold in 64% of tumors. Overall, 90.3% of the tumors exhibited at least 1 alteration in a TGF-B signaling component and synchronous alterations in multiple components were seen in 62%. Conclusion: Alterations of TGF-B signaling components are common events in HNSCC. These alterations can occur at transcriptional levels or at the protein level. Significance: Alterations of TGF-B signaling components may play a role in HNSCC progression. Since these alterations are common in HNSCC, manipulation of this signal transduction pathway may be a potential prognostic biomarker or therapeutic target in the future. Support: None reported.