Dae-hee Lee - Academia.edu (original) (raw)

Papers by Dae-hee Lee

Cells, 2021

Swift and continuous phagocytosis of apoptotic cells can be achieved by modulation of calcium flu... more Swift and continuous phagocytosis of apoptotic cells can be achieved by modulation of calcium flux in phagocytes. However, the molecular mechanism by which apoptotic cells modulate calcium flux in phagocytes is incompletely understood. Here, using biophysical, biochemical, pharmaceutical, and genetic approaches, we show that apoptotic cells induced the Orai1-STIM1 interaction, leading to store-operated calcium entry (SOCE) in phagocytes through the Mertk-phospholipase C (PLC) γ1-inositol 1,4,5-triphosphate receptor (IP3R) axis. Apoptotic cells induced calcium release from the endoplasmic reticulum, which led to the Orai1-STIM1 association and, consequently, SOCE in phagocytes. This association was attenuated by masking phosphatidylserine. In addition, the depletion of Mertk, which indirectly senses phosphatidylserine on apoptotic cells, reduced the phosphorylation levels of PLCγ1 and IP3R, resulting in attenuation of the Orai1-STIM1 interaction and inefficient SOCE upon apoptotic ce...

Journal of Neurosurgery, 2012

Object Tumor-initiating cells are uniquely resilient to current treatment modalities and play an ... more Object Tumor-initiating cells are uniquely resilient to current treatment modalities and play an important role in tumor resistance and recurrence. The lack of specific tumor-initiating cell markers to identify and target these cells presents a major obstacle to effective directed therapy. Methods To identify tumor-initiating cell markers in primary brain tumors, the authors compared the proteomes of glioma tumor-initiating cells to their differentiated progeny using a novel, nongel/shotgun-based, multidimensional liquid-chromatography protein separation technique. An in vivo xenograft model was used to demonstrate the tumorigenic and stem cell properties of these cells. Western blot and immunofluorescence analyses were used to confirm findings of upregulated ciliary neurotrophic factor receptor subunit–α (CNTFRα) in undifferentiated tumor-initiating cells and gliomas of increasing tumor grade. Sequencing of the CNTFRα coding regions was performed for mutation analysis. Finally, ant...

Oncology Reports, 2018

Imatinib is a powerful tyrosine kinase inhibitor that specifically targets BCR-ABL, c-KIT, and PD... more Imatinib is a powerful tyrosine kinase inhibitor that specifically targets BCR-ABL, c-KIT, and PDGFR kinases, and is used in the treatment of chronic myelogenous leukemia, gastrointestinal stromal tumors, and other types of cancers. However, the possible anticancer effects of imatinib in gastric cancer have not yet been explored. The present study evaluated the in vitro effects of imatinib on gastric cancer cells and determined the molecular mechanism underlying these effects. We determined that imatinib induced mitochondria-mediated apoptosis of gastric cancer cells by involving endoplasmic reticulum (ER) stress-associated activation of c-Jun NH 2-terminal kinase (JNK). We also found that imatinib suppressed cell proliferation in a time-and dose-dependent manner. Cell cycle analysis revealed that imatinib-treated AGS cells were arrested in the G2/M phase of the cell cycle. Moreover, imatinib-treated cells exhibited increased levels of phosphorylated JNK, and of the transcription factor C/EBP homologous protein, an ER stress-associated apoptotic molecule. Results of cell viability assays revealed that treatment with a combination of imatinib and chemotherapy agents irinotecan or 5-Fu synergistically inhibited cell growth, compared with treatment with any of these drugs alone. These data indicated that imatinib exerted cytotoxic effects on gastric cancer cells by inducing apoptosis mediated by reactive oxygen species generation and ER stress-associated JNK activation. Furthermore, we revealed that imatinib induced the apoptosis of gastric cancer cells by inhibiting platelet-derived growth factor receptor signaling. Collectively, our results strongly support the use of imatinib in the treatment of treating gastric cancer.

PloS one, 2018

Metformin, a first-line drug used to treat type 2 diabetes, has also been shown to have anticance... more Metformin, a first-line drug used to treat type 2 diabetes, has also been shown to have anticancer effects against a variety of malignancies, including colorectal cancer. Although inhibition of the mTOR pathway is known to be the most important mechanism for the antitumor effects of metformin, other mechanisms remain unclear. The purpose of this study was to identify the antitumor mechanism of metformin in colorectal cancer using high-throughput data, and then test the mechanism experimentally. We identified the gene signature of metformin-treated colon cancer cells. This signature was processed for prediction using colon adenocarcinoma patient data from the Cancer Genome Atlas to classify the patients showing a gene expression pattern similar to that in metformin-treated cells. This patient group showed better overall and disease-free survival. Furthermore, pathway analysis revealed that the metformin-predicted group was characterized by decreased interleukin (IL)-6 pathway signali...

Cell Death & Differentiation, 2018

An essential step during clearance of apoptotic cells is the recognition of phosphatidylserine (P... more An essential step during clearance of apoptotic cells is the recognition of phosphatidylserine (PS) exposed on apoptotic cells by its receptors on phagocytes. Tim-4 directly binding to PS and functioning as a tethering receptor for phagocytosis of apoptotic cells has been extensively studied over the past decade. However, the molecular mechanisms by which Tim-4 collaborates with other engulfment receptors during efferocytosis remain elusive. By comparing efferocytosis induced by Tim-4 with that by Anxa5-GPI, an artificial tethering receptor, we found that Tim-4 possesses auxiliary machinery to induce a higher level of efferocytosis than Anxa5-GPI. To search for that, we performed a yeast two-hybrid screen and identified Fibronectin (Fn1) as a novel Tim-4-associating protein. Tim-4 directly associated with Fn1 and formed a complex with integrins via the association of Fn1. Through Tim-4 −/− mice and cell-based assays, we found that modulation of the Fn1 level affected efferocytosis induced by Tim-4 and disruption of the interaction between Tim-4 and Fn1 abrogated Tim-4mediated efferocytosis. In addition, Tim-4 depletion attenuated integrin signaling activation and perturbation of integrin signaling suppressed Tim-4-promoted efferocytosis. Taken together, the data suggest that Fn1 locates Tim-4 and integrins in close proximity by acting as a scaffold, resulting in synergistic cooperation of Tim-4 with integrins for efficient efferocytosis.

Oncotarget, Jan 29, 2017

Ferroptosis is a type of programmed cell death that depends on iron and is characterized by the a... more Ferroptosis is a type of programmed cell death that depends on iron and is characterized by the accumulation of lipid peroxides. In the present study, we investigated the nature of the interplay between ferroptosis and other forms of cell death such as apoptosis. Human pancreatic cancer PANC-1 and BxPC-3 and human colorectal cancer HCT116 cells were treated with ferroptotic agents such as erastin and artesunate (ART) in combination with the apoptotic agent tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). We observed synergistic interaction of erastin or ART with TRAIL as determined by cell death assay, caspase activation, poly [ADP-ribose] polymerase 1 (PARP-1) cleavage, flow cytometry analysis, and lipid peroxidation assay. Moreover, erastin and ART induced endoplasmic reticulum (ER) stress and promoted p53 upregulated modulator of apoptosis (PUMA) expression via C/EBP-homologous protein (CHOP). Synergy of erastin/ART and TRAIL was abolished in PUMA-deficient HCT116...

Molecular cancer research : MCR, Jan 28, 2018

Since its discovery in 2012, ferroptosis has been well characterized by the accumulation of lipid... more Since its discovery in 2012, ferroptosis has been well characterized by the accumulation of lipid peroxides due to the failure of glutathione-dependent antioxidant defenses. It is known as an iron-dependent form of programmed cell death, which is distinct from other forms of cell death such as apoptosis and necrosis. Nonetheless, little is known about the ferroptotic agent-induced endoplasmic reticulum (ER) stress response and its role in cell death. Recent studies reveal that the ferroptotic agent-induced ER stress response plays an important role in the cross-talk between ferroptosis and other types of cell death. Ferroptotic agents induce the unfolded protein response and subsequently ER stress-mediated activation of the PERK-eIF2α-ATF4-CHOP pathway. CHOP (C/EBP homologous protein) signaling pathway-mediated p53-independent PUMA (p53 upregulated modulator of apoptosis) expression is involved in the synergistic interaction between ferroptosis and apoptosis. This review highlights ...

Molecular cancer research : MCR, Jan 18, 2018

Emerging evidence demonstrates that autophagy and apoptosis are interconnected and their interpla... more Emerging evidence demonstrates that autophagy and apoptosis are interconnected and their interplay greatly affects cell death. However, the key regulators in this crosstalk remain elusive. Therefore, the role of N-terminal arginylated BiP (R-BiP)/Beclin-1/p62 complex was examined in the crosstalk between apoptosis and autophagy during combination chemotherapy with mitomycin C and bortezomib using immunoblot, immunoprecipitation, and cellular imaging assays in wild-type (WT) and genetically engineered colorectal cancer cells. In addition, the tumoricidal efficacy of the combinatorial treatment in a nude mouse tumor xenograft model of colorectal cancer was assessed. Bortezomib combined with mitomycin C synergistically induced cytotoxicity and apoptosis rather than autophagy. Mechanistically, this combination inactivated Akt and subsequently induced Beclin-1 () dephosphorylation at Ser 234/295. Dephosphorylation of Beclin-1 resulted in increased cleavage of Beclin-1 and disruption of t...

Oncotarget, Jan 24, 2017

Genipin, a major component ofEllis fruit, has been shown to inhibit the growth of gastric, prosta... more Genipin, a major component ofEllis fruit, has been shown to inhibit the growth of gastric, prostate, and breast cancers. However, the anti-proliferative activity of genipin in colorectal cancer (CRC) has not been characterized. Herein, we demonstrated that genipin inhibits the proliferation of CRC cells and that genipin suppressed the Hedgehog pathway. Further investigation showed that p53 and NOXA protein levels were increased during inhibition of Hedgehog pathway-mediated apoptosis in CRC cells. We also showed that p53 modulated the expression of NOXA during genipin-induced apoptosis, and suppression via SMO also played a role in this process. Subsequently, GLI1 was ubiquitinated by the E3 ligase PCAF. In a xenograft tumor model, genipin suppressed tumor growth, which was also associated with Hedgehog inactivation. Taken together, these results suggest that genipin induces apoptosis through the Hedgehog signaling pathway by suppressing p53. These findings reveal a novel regulatory...

Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine, 2017

The sonic hedgehog signaling pathway is critical for cell proliferation, cell differentiation, an... more The sonic hedgehog signaling pathway is critical for cell proliferation, cell differentiation, and organ development during embryogenesis. Aberrant activation of the sonic hedgehog pathway has been associated with a variety of human cancers. Currently, there is no target molecular drug that clinically affects sonic hedgehog activation in patients with gastric cancer. In this review, we will focus on the current clinical treatment options for advanced gastric cancer and discuss the sonic hedgehog signaling pathway. We also review our understanding of the role of sonic hedgehog signaling in advanced gastric cancer progression. Finally, we will describe current known molecular pathways that crosstalk with the sonic hedgehog pathway in cancer stem cells.

Oncotarget, 2017

Tissue hypoxia contributes to solid tumor pathogenesis by activating a series of adaptive program... more Tissue hypoxia contributes to solid tumor pathogenesis by activating a series of adaptive programs. We previously showed that hypoxia promotes the preferential expansion and maintenance of CD133 positive human glioma stem cells (GSC) in a hypoxia inducible factor 1 alpha (HIF-1α)-dependent mechanism. Here, we examined the activity of digitoxin (DT), a cardiac glycoside and a putative inhibitor of HIF-1α, on human GSC in vitro and in vivo. During hypoxic conditions (1% O 2), we observed the effect of DT on the intracellular level of HIF-1α and the extracellular level of vascular endothelial growth factor (VEGF) in human GSC. We found that DT at clinically achievable concentrations, suppressed HIF-1α accumulation during hypoxic conditions in human GSC and established glioma cell lines. DT treatment also significantly attenuated hypoxia-induced expression of VEGF, a downstream target of HIF-1α. Exposure to DT also reduced hypoxia-induced activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. Furthermore, DT potently inhibited neurosphere formation, and decreased CD133 expression even at concentrations that were not overtly cytotoxic. Lastly, treatment with DT reduced GSC engraftment in an in vivo xenograft model of glioblastoma. Intraperitoneal injections of DT significantly inhibited the growth of established glioblastoma xenografts, and suppressed expression of HIF-1α and carbonic anhydrase (CA9), a surrogate marker of hypoxia. Taken together, these results suggest that DT at clinically achievable concentration functions as an inhibitor of HIF-1α, worthy of further investigations in the therapy of glioblastoma.

EMBO reports, 2017

Although proteasome inhibitors (PIs) are used as anticancer drugs to treat various cancers, their... more Although proteasome inhibitors (PIs) are used as anticancer drugs to treat various cancers, their relative therapeutic efficacy on stem cells vs. bulk cancers remains unknown. Here, we show that stem cells derived from gliomas, GSCs, are up to 1,000-fold more sensitive to PIs (IC50, 27-70 nM) compared with their differentiated controls (IC50, 47 to »100 μM). The stemness of GSCs correlates to increased ubiquitination, whose misregulation readily triggers apoptosis. PI-induced apoptosis of GSCs is independent of NF-κB but involves the phosphorylation of c-Jun N-terminal kinase as well as the transcriptional activation of endoplasmic reticulum (ER) stress-associated proapoptotic mediators. In contrast to the general notion that ER stress-associated apoptosis is signaled by prolonged unfolded protein response (UPR), GSC-selective apoptosis is instead counteracted by the UPR ATF3 is a key mediator in GSC-selective apoptosis. Pharmaceutical uncoupling of the UPR from its downstream apopt...

Oncology Reports, 2016

Recent studies have determined that inactivation of runt-related transcription factor 3 (RUNX3) e... more Recent studies have determined that inactivation of runt-related transcription factor 3 (RUNX3) expression is highly associated with lymph node metastasis and poor prognosis in various types of cancer. However, the mechanism of RUNX3-mediated suppression of tumor metastasis remains unclear. Herein, we aimed to clarify the effect of RUNX3 on metastasis and angiogenesis in colorectal cancer (CRC). Firstly, we found that the reduction in expression of RUNX3 in CRC tissues when compared with tumor adjacent normal colon tissues, as indicated by reduced RUNX3 staining, was significantly correlated with tumor-node-metastasis (TNM) stage. Secondly, we demonstrated that RUNX3 overexpression inhibited CRC cell migration and invasion resulting from the upregulation of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression. In contrast, the knockdown of RUNX3 reduced the inhibition of migration and invasion of CRC cells. Finally, we found that restoration of RUNX3 decreased vascular endothelial growth factor (VEGF) secretion and suppressed endothelial cell growth and tube formation in CRC cells. All in all, our findings may provide insight into the development of RUNX3 for CRC metastasis diagnostics and therapeutics.

Molecular Medicine Reports, 2016

Triple-negative breast cancer (TNBC) is a breast cancer subtype that has an aggressive phenotype,... more Triple-negative breast cancer (TNBC) is a breast cancer subtype that has an aggressive phenotype, is highly metastatic, has limited treatment options and is associated with a poor prognosis. In addition, metastatic TNBC has no preferred standard chemotherapy due to resistance to anthracyclines and taxanes. The present study demonstrated that a herbal extract, SH003, reduced cell viability and induced apoptosis in TNBC without cell cytotoxicity. Cell viability was examined using trypan blue exclusion and colony formation assays, which revealed a decrease in the cell viability. Additionally, apoptosis was determined using flow cytometry and a sub-G1 assay, which revealed an increase in the proportion of cells in the sub-G1 phase. The present study investigated the anticancer effect of SH003 in the Hs578T, MDA-MB-231 and ZR-751 TNBC cell lines, and in the MCF7 and T47D non-TNBC cell lines. Western blot analysis revealed that the expression levels of poly-ADP-ribose polymerase (PARP) cleavage protein in cells treated with SH003 were increased dose-dependent manner, indicating that SH003 induced apoptosis via a caspase-dependent pathway. Pre-treatment with the caspase inhibitor Z-VAD reduced SH003-induced apoptosis was examined using trypan blue exclusion. Moreover, SH003 treatment enhanced the p73 levels in MDA-MB-231 cells but not in MCF7 cells. Transfection of p73 small interfering RNA (siRNA) in MDA-MB0231 cells revealed that the apoptotic cell death induced by SH003 was significantly impaired in comparison with scramble siRNA transfected MDA-MB-231 cells. This was examined using trypan blue exclusion and flow cytometry analysis (sub-G1). In addition, SH003 and paclitaxel exhibited synergistic anticancer effects on TNBC cells. The results indicate that SH003 exerts its anticancer effect via p73 protein induction and exhibits synergistic anticancer effects when combined with paclitaxel.

Oncotarget, Jan 9, 2016

Metformin is an anti-diabetic drug with a promising anti-cancer potential. In this study, we show... more Metformin is an anti-diabetic drug with a promising anti-cancer potential. In this study, we show that subtoxic doses of metformin effectively sensitize human colorectal cancer (CRC) cells to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), which induces apoptosis. Metformin alone did not induce apoptosis, but significantly potentiated TRAIL-induced apoptosis in CRC cells. CRC cells treated with metformin and TRAIL showed activation of the intrinsic and extrinsic pathways of caspase activation. We attempted to elucidate the underlying mechanism, and found that metformin significantly reduced the protein levels of myeloid cell leukemia 1 (Mcl-1) in CRC cells and, the overexpression of Mcl-1 inhibited cell death induced by metformin and/or TRAIL. Further experiments revealed that metformin did not affect mRNA levels, but increased proteasomal degradation and protein stability of Mcl-1. Knockdown of Mule triggered a significant decrease of Mcl-1 polyubiquitination...

Cancer research and treatment : official journal of Korean Cancer Association, Jan 18, 2016

Reactive oxygen species modulator 1 (Romo1) is a key mediator of intracellular reactive oxygen sp... more Reactive oxygen species modulator 1 (Romo1) is a key mediator of intracellular reactive oxygen species production. However, examination of the clinical usefulness of Romo1 in cancers has been limited. We evaluated the association of Romo1 expression with clinical outcomes in advanced non-small cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy. Romo1 expression in tumor tissue was examined by immunohistochemistry and evaluated by histological score. Survival analyses were performed according to Romo1 expression and the association between Romo1 expression and clinical parameters was evaluated. A total of 88 tumor specimens were analyzed. Significantly shorter median progression-free survival (PFS) was observed in the high Romo1 group compared with the low Romo1 group (4.5 vs 9.8 months, p < 0.001), and the median overall survival (OS) of the high Romo1 group was also significantly shorter than that of the low Romo1 group (8.4 vs 15.5 months, p < 0.001)....

Molecular cancer therapeutics, Jan 8, 2015

The MET receptor tyrosine kinase, the receptor for hepatocyte growth factor (HGF), has been impli... more The MET receptor tyrosine kinase, the receptor for hepatocyte growth factor (HGF), has been implicated in cancer growth, invasion, migration, angiogenesis, and metastasis in a broad variety of human cancers, including human hepatocellular carcinoma (HCC). Recently, MET was suggested to be a potential target for the personalized treatment of HCC with an active HGF/MET signaling pathway. However, the mechanisms of resistance to MET inhibitors need to be elucidated in order to provide effective treatment. Here, we show that HCC cells exhibit different sensitivities to the MET inhibitor PHA665752, depending on the phosphorylation status of fibroblast growth factor receptor (FGFR). Treatment of cells expressing both phospho-FGFR and phospho-MET, with the inhibitor PHA665752, did not cause growth inhibition and cell death, whereas treatment with AZD4547, a pan-FGFR inhibitor, resulted in decreased colony formation and cleavage of caspase-3. Moreover, silencing of endogenous FGFR1 and FGFR...

Molecules and Cells, 2015

Rapid and efficient engulfment of apoptotic cells is an essential property of phagocytes for remo... more Rapid and efficient engulfment of apoptotic cells is an essential property of phagocytes for removal of the large number of apoptotic cells generated in multicellular organisms. To achieve this, phagocytes need to be able to continuously uptake apoptotic cells. It was recently reported that uncoupling protein 2 (Ucp2) promotes engulfment of apoptotic cells by increasing the phagocytic capacity, thereby allowing cells to continuously ingest apoptotic cells. However, the functions of Ucp2, beyond its possible role in dissipating the mitochondrial membrane potential, that contribute to elevation of the phagocytic capacity have not been determined. Here, we report that the anion transfer or nucleotide binding activity of Ucp2, as well as its dissipation of the mitochondrial membrane potential, is necessary for Ucp2-mediated engulfment of apoptotic cells. To study these properties, we generated Ucp2 mutations that affected three different functions of Ucp2, namely, dissipation of the mitochondrial membrane potential, transfer of anions, and binding of purine nucleotides. Mutations of Ucp2 that affected the proton leak did not enhance the engulfment of apoptotic cells. Although anion transfer and nucleotide binding mutations did not affect the mitochondrial membrane potential, they exerted a dominant-negative effect on Ucp2-mediated engulfment. Furthermore, none of our Ucp2 mutations increased the phagocytic capacity. We conclude that dissipation of the proton gradient by Ucp2 is not the only determinant of the phagocytic capacity and that anion transfer or nucleotide binding by Ucp2 is also essential for Ucp2-mediated engulfment of apoptotic cells. 1