Hsa_circ_0014784-induced YAP1 promoted the progression of pancreatic cancer by sponging miR-214-3p.

BACKGROUND: Pancreatic cancer (PC) is one of the most common gastrointestinal tumors globally. Former investigations discovered that circular RNAs (circRNAs) play an important role in PC development. circRNAs belong to a new class of endogenous noncoding RNAs, which have been found to mediate the progression of diverse types of tumors. Nevertheless, the roles of circRNAs and the underlying regulatory mechanisms in PC remain unknown. METHODS: In this study, our team employed next-generation sequencing (NGS) to examine the abnormal circRNA expression in PC tissues. The circRNA expression in PC cell lines and tissues was detected. Then, regulatory mechanism and targets were examined with bioinformatics analysis, luciferase reporting analysis, Transwell migration, 5-ethynyl-2'-deoxyuridine, and CCK-8 analysis. An in vivo experiment was employed to elucidate hsa_circ_0014784 roles in PC tumor growth and metastasis. RESULTS: The results showcased abnormal circRNA expression in PC tissues. Our lab also found that hsa_circ_0014784 expression incremented in PC tissues and cell lines, implying that hsa_circ_0014784 functioned in PC progression. hsa_circ_0014784 downregulation inhibited PC proliferation and invasion in vivo and in vitro. The bioinformatics and luciferase report data validated that both miR-214-3p and YAP1 were hsa_circ_0014784 binding partners. The overexpression of YAP1 reversed the migration, proliferation, and epithelial - mesenchymal transition (EMT) of PC cells and the angiogenic differentiation of HUVECs after miR-214-3p overexpression. CONCLUSION: Taken together, our study found that hsa_circ_0014784 downregulation decremented invasion, proliferation, EMT, and angiogenesis of PC by regulating miR-214-3p/YAP1 signaling.

GPX2 stabilized by PCBP2 induces autophagy to protect Het-1A esophageal cells from apoptosis and inflammation.

The implantation of esophageal stent loaded with iodine-125 (125I) is one of the critical approaches for the treatment of advanced esophageal cancer, but one common complication after stent implantation is benign hyperplasia associated restenosis. The aim of the current study is to understand the role of glutathione peroxidase 2 (GPX2), a key member of the GPX family of antioxidant enzymes. Initially, we detected the increased levels of GPX2 and GPX1 in esophageal benign hyperplasia tissues. Further, we evaluated the effects of GPX2 in response to H2O2 induced apoptosis and LPS induced inflammation. We observed that GPX2 expression was also significantly increased in Het-1A. Silencing of GPX2 significantly increased H2O2-induced apoptosis and LPS-induced inflammation, but GPX2 overexpression did the opposite, suggesting a protective effect by GPX2. In addition, we identified that the protective effect of GPX2 is through the activation of autophagy, and PCBP2, a poly (rC) binding protein, binds to and stabilizes GPX2 mRNA. These findings reveal a role of GPX2 in esophageal hyperplasia, allowing for a better understanding of the underlying molecular mechanism, which could lead to identification of potential treatment for clinical benign restenosis following stent implantation with 125I.

GPx8 regulates apoptosis and autophagy in esophageal squamous cell carcinoma through the IRE1/JNK pathway.

Glutathione peroxidase 8 (GPx8) belongs to a family of enzymes that have a critical role in controlling levels of reactive oxygen species (ROS). GPX family members have been associated with several cancers. Here, we examined the role of GPx8 in esophageal squamous cell carcinoma (ESCC). Immunohistochemical staining and western blot analysis were used to study the clinical significance of GPx8 in ESCC tissue. GPx8 was further evaluated in cells by MTT assay and colony formation. RT-PCR, western blot, immunofluorescence staining, TUNEL assay, TEM, and flow cytometry were used to assess the molecular mechanism underlying endoplasmic reticulum (ER) stress associated with GPx8 in ESCC cells. Xenografted tumor growth was used to assess the in vivo role of GPx8. We found that GPx8 was overexpressed in both ESCC cell lines and tumor tissue. GPx8 knockdown significantly suppressed ESCC proliferation and induced autophagy and apoptosis in ESCC cell lines, whereas GPx8 overexpression led to increased proliferation and inhibition of apoptosis. GPx8-mediated inhibition of apoptosis was associated with the ER stress pathway through inositol-requiring enzyme 1 (IRE1) and Jun N-terminal kinase (JNK). Knockdown of GPx8 in xenograft models of ESCC resulted in a significant reduction in tumor weight and volume, which was further reduced with IRE1 or JNK inhibitors. Our study suggests that GPx8 regulates apoptosis and autophagy in ESCC through the IRE1/JNK pathway in response to ER stress. Targeting this pathway might be a potential therapeutic strategy for ESCC.

HP1BP3 promotes tumor growth and metastasis by upregulating miR-23a to target TRAF5 in esophageal squamous cell carcinoma.

HP1BP3, an ubiquitously expressed nuclear protein belonging to the H1 histone family of proteins, plays an important role in cell growth and viability. Recently, it was reported that HP1BP3 exclusively regulates miRNA biogenesis by enhancing transcriptional miRNA processing. Although HP1BP3 has previously been implicated in common cancer types, the mechanistic functions and effects of HP1BP3 and its role in the prognosis of esophageal squamous cell carcinoma (ESCC) remain unclear. Here, we report that ESCC tissues and cell lines show increased endogenous expression of HP1BP3. Knockdown of HP1BP3 in TE-1 cells significantly inhibited tumor growth and metastasis in vivo emphasizing its role in cell proliferation and invasion. In contrast, overexpression of HP1BP3 significantly enhanced tumor growth and metastasis in Eca-109 cells. Further, we found that HP1BP3 regulates these functions by upregulating miR-23a, which directly binds to the 3'UTR region of TRAF5 downstream to alter cell survival and proliferation. Our findings describe a role for HP1BP3 in promoting tumor growth and metastasis by upregulating miR-23a to target TRAF5 in esophageal cancer. This study provides novel insights into the potential of targeting miRNAs for therapy and as clinical markers for cancer progression.

TRIM11 suppresses ferritinophagy and gemcitabine sensitivity through UBE2N/TAX1BP1 signaling in pancreatic ductal adenocarcinoma.

Gemcitabine is first-line chemotherapy for pancreatic cancer, however, the development of resistance limits its effectiveness. The tripartite motif-containing 11 (TRIM11) protein plays crucial roles in tumor development and undergoes auto-polyubiquitination to promote interactions in selective autophagy. Therefore, Understanding whether TRIM11 is involved in ferritinophagy and gemcitabine resistance in pancreatic cancer is critical in developing pancreatic cancer therapeutics. TRIM11 expression was validated by Western blot analysis, real-time polymease chain reaction, and immunohistochemical staining. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Colony formation assays were performed to investigate pancreatic ductal adenocarcinomas (PDAC) cell viability. Mouse xenograft model of PDAC cells was established to verify the role of TRIM11 in vivo. Coimmunoprecipitation was used to identify the reciprocal regulation between TRIM11 and UBE2N. In this study, we found that TRIM11 expression were higher in PDAC cells and tissues. TRIM11 overexpression promotes PDAC cell proliferation in vitro and tumor growth in vivo. Decreased expression of TRIM11 in PDAC patients is associated with decreased UBE2N and increased TAX1BP1 expression. Coimmunoprecipitation established that TRIM11 interacts and colocalizes with UBE2N. Mechanistically, TRIM11 promoted gemcitabine resistance and suppressed ferritinophagy through UBE2N-TAX1BP1 signaling. Our findings identify TRIM11 as a key regulator of TAX1BP1 signaling with a crucial role in ferritinophagy and gemcitabine resistance in PDAC.

PTBP3 promotes malignancy and hypoxia-induced chemoresistance in pancreatic cancer cells by ATG12 up-regulation.

Pancreatic ductal adenocarcinoma (PDAC) tumours exhibit a high level of heterogeneity which is associated with hypoxia and strong resistance to chemotherapy. The RNA splicing protein polypyrimidine tract-binding protein 3 (PTBP3) regulates hypoxic gene expression by selectively binding to hypoxia-regulated transcripts. We have investigated the role of PTBP3 in tumour development and chemotherapeutic resistance in human PDAC tissues and pancreatic cancer cells. In addition, we determined the sensitivity of cancer cells to gemcitabine with differential levels of PTBP3 and whether autophagy and hypoxia affect gemcitabine resistance in vitro. PTBP3 expression was higher in human pancreatic cancer than in paired adjacent tissues. PTBP3 overexpression promoted PDAC proliferation in vitro and tumour growth in vivo, whereas PTBP3 depletion had opposing effects. Hypoxia significantly increased the expression of PTBP3 in pancreatic cancer cells in vitro. Under hypoxic conditions, cells were more resistance to gemcitabine. Knockdown of PTBP3 results in decreased resistance to gemcitabine, which was attributed to attenuated autophagy. We propose that PTBP3 binds to multiple sites in the 3'-UTR of ATG12 resulting in overexpression. PTBP3 increases cancer cell proliferation and autophagic flux in response to hypoxic stress, which contributes to gemcitabine resistance.

Identification of Critical Genes and Proteins for Stent Restenosis Induced by Esophageal Benign Hyperplasia in Esophageal Cancer.

This study was conducted to explore the potential genes and proteins associated with esophagus benign hyperplasia induced by esophageal stents. Five patients with esophageal cancer subjected to esophageal stent placement were enrolled in this study. Long non-coding RNA (lncRNA) sequencing and tandem mass tag quantitative proteomics analysis were performed by using the collected hyperplastic samples and adjacent non-hyperplastic tissues. Differentially expressed (DE) RNAs and proteins were analyzed, followed by functional enrichment analysis, protein-protein interaction (PPI) network analysis, and competitive endogenous RNA (ceRNA) network construction. Venn analysis was performed to extract the overlaps between DE mRNAs and DE proteins and the expression correlations between DE mRNA and proteins were analyzed. Results showed that total 642 DE RNAs (457 mRNA and 185 lncRNAs) and 256 DE proteins were detected. DE mRNAs (such as MAOB, SDR16C5, and FOSL1) were enriched in oxidation-reduction process-associated functions. PPI network was comprised of 175 nodes and 425 edges. VEGFA was a significant node with the highest degree. LncRNA-mRNA network with three subnetworks (C1, C2, C3) was constructed for lncRNAs with more than 15 gene targets. RP11-58O9.2 was a significant lncRNA with the most target genes and RP11-667F14.1 regulated more than 20 targets. FOSL1 was a common target of the two lncRNAs. Function analysis showed that DE lncRNAs were involved in the HTLV-I infection (RP11-58O9.2 and RP11-667F14.1) and IL-17 signaling pathways (RP11-5O24.1 and RP11-58O9.2). Total 11 DE mRNAs were overlapped with DE proteins, among which MAOB and SDR16C5 showed positive correlations between mRNA and protein expression. Function analysis showed that MAOB was enriched in oxidation-reduction process and its protein was closely related with response to lipopolysaccharide. VEGFA, FOSL1, MAOB, SDR16C5, RP11-58O9.2, RP11-667F14.1, and RP11-288A5.2 may be served as genetic targets for preventing stent restenosis in esophageal cancer.

lncRNA GAS5 Reverses EMT and Tumor Stem Cell-Mediated Gemcitabine Resistance and Metastasis by Targeting miR-221/SOCS3 in Pancreatic Cancer.

Dysregulated long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) mediating chemotherapeutic drug effects and metastasis in pancreatic cancer (PC) are key reasons for the poor prognosis of this disease. lncRNA growth arrest-specific 5 (GAS5) is reported to be a tumor suppressor in multiple cancers. However, the functions of GAS5 and its related miRNAs in PC are poorly understood. This study explored the potential functions and mechanisms of GAS5 in PC gemcitabine resistance and metastasis. The results show that overexpression of GAS5 suppressed the proliferation, migration, gemcitabine resistance, stem cell-like properties, and epithelial-mesenchymal transition (EMT) of PC cells by directly binding to and suppressing miR-221 expression and enhancing suppressor of cytokine signaling 3 (SOCS3) expression. The effects of miR-221 overexpression on proliferation, migration, gemcitabine resistance, stem cell-like properties, and EMT inhibition were reversed by SOCS3 overexpression in PC cells. Additionally, GAS5 promoted gemcitabine-induced tumor growth and metastasis inhibition, as determined by Ki-67 staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), bioluminescence imaging, and the detection of cell-like properties and EMT in vivo. Thus, lncRNA GAS5 functioned as a competing endogenous RNA for miR-221, and it suppressed cell growth, metastasis, and gemcitabine resistance in PC by regulating the miR-221/SOCS3 pathway mediating EMT and tumor stem cell self-renewal.

Plumbagin, a natural naphthoquinone, inhibits the growth of esophageal squamous cell carcinoma cells through inactivation of STAT3.

Although plumbagin, a natural naphthoquinone, has exhibited antiproliferative activity in numerous types of cancer, its anticancer potential in esophageal squamous cell carcinoma (ESCC) remains unclear. In the present study, the effect of plumbagin on the growth of ESCC cells was investigated in vitro and in vivo. ESCC cells were treated with plumbagin and tested for cell cycle distribution and apoptosis. The involvement of STAT3 signaling in the effect of plumbagin was examined. The results demonstrated that plumbagin treatment suppressed ESCC cell viability and proliferation, yet normal esophageal epithelial cell viability was not affected. Plumbagin treatment increased the proportion of cells in the G0/G1 phase of the cell cycle and decreased the proportion of cells in the S phase. Furthermore, plumbagin­treated ESCC cells displayed a significantly greater % of apoptotic cells. Western blot analysis confirmed that plumbagin upregulated tumor protein p53 and cyclin­dependent kinase inhibitor 1A (also known as p21), while it downregulated cyclin D1, cyclin­dependent kinase 4, and induced myeloid leukemia cell differentiation protein Mcl­1. Mechanistically, plumbagin inhibited STAT3 activation, and overexpression of constitutively active STAT3 reversed the plumbagin­mediated growth suppression in ESCC cells. In vivo studies demonstrated that plumbagin delayed the growth of ESCC xenograft tumors and reduced STAT3 phosphorylation. Overall, plumbagin was demonstrated to target STAT3 signaling and to inhibit the growth of ESCC cells both in vitro and in vivo, suggesting that it may represent a potential anticancer agent for ESCC.

MiR-124 induces autophagy-related cell death in cholangiocarcinoma cells through direct targeting of the EZH2-STAT3 signaling axis.

Cholangiocarcinoma (CCA) is a lethal cancer associated with chronic inflammation that has increased in prevalence in recent decades. The dysregulated expression of microRNAs (miRNAs) has been detected in various types of malignancies, and depending on the target genes this can result in miRNAs functioning as tumor suppressors or oncogenes. In this study, we investigated the role of miR-124 in cholangiocarcinoma (CCA) and found that its expression was significantly downregulated in the tumor tissue of patients and in CCA cell lines. Our results provided evidence that miR-124 induces apoptotic cell death and triggers the autophagic flux in CCA cells. EZH2 and STAT3 were identified as direct targets of miR-124. The effect of miR-124 on EZH2 expression in CCA cells was evaluated using cell transfection, xenotransplantation into nude mice and a luciferase reporter assay. Silencing of EZH2 restored the effects of miR-124, whereas overexpression of EZH2 abrogated the effects of miR-124. Silencing of Beclin1 or ATG5 abrogated the effects of miR-124 or siEZH2. In vivo, overexpression of miR-124 dramatically induced autophagy-related cell death and suppressed tumorigenicity. Taken together, our findings indicated that downregulation of miR-124 expression was associated with disease progression in human CCA and we revealed that miR-124 exerts a tumor suppressive function in CCA by inducing autophagy-related cell death via direct targeting of the EZH2-STAT3 signaling axis.

MiR-4262 promotes cell apoptosis and inhibits proliferation of colon cancer cells: involvement of GALNT4.

A role of microRNA-4262 (miR-4262) in the carcinogenesis of colon cancer remains undetermined. In this study, we studied the effects and mechanisms of miR-4262 to the colon cancer cell proliferation and apoptosis. We found that the levels of miR-4262 significantly down-regulated in colon cancer tissue, compared to the paired adjacent non-tumor colon tissue. The miR-4262 levels in colon cancer cell lines were significantly lower than those in control normal colon tissues. Transfection with the miR-4262 mimic decreased the cell proliferation and increased cell apoptosis in colon cancer cells, while transfection with the antisense of miR-4262 (as-miR-4262) increased cell proliferation and suppressed cell apoptosis in colon cancer cells. Bioinformatics analyses showed that GALNT4 was a potential target gene of miR-4262. The luciferase activities assay and Western blot verified that miR-4262 targeted GALNT4 mRNA to modulate its protein levels. When we treated cells with miR-4262 and GALN4 siRNA, the cell viability was significantly decreased. Together, our study suggests that aberrantly expressed miR-4262 may affect cell apoptosis and proliferation of human colon cancer cells via GALNT4, which appears to be a promising therapeutic target for colon cancer.

Tumor-associated macrophage-derived CCL20 enhances the growth and metastasis of pancreatic cancer.

Pancreatic cancer is an aggressive malignancy with a high metastatic potential that results in a high mortality rate worldwide. Although macrophages have the potential to kill tumor cells and elicit immune responses against tumors, there is evidence that tumor-associated macrophages (TAMs) promote tumor progression and suppress T-cell responses. CC-chemokine ligand 20 (CCL20) and its unique receptor CC-chemokine receptor 6 (CCR6) are exploited by cancer cells for migration and metastasis and play important roles in the development and progression of cancer. Recent studies have shown that the expression of CCL20 is upregulated in pancreatic cancer; however, the mechanism of action of CCL20 remains to be fully elucidated. In this study, the aberrant expression of CCL20 in TAMs of pancreatic cancer tissue, including metastatic pancreatic cancer tissue, was detected. CCL20 expression was considerably higher in macrophages than in pancreatic cancer cell lines, particularly in interleukin-4-treated (M2) macrophages. Using Boyden chamber assays of pancreatic cancer cells, we found that CCL20 secreted by M2 macrophages promoted the migration, epithelial-mesenchymal transition, and invasion of pancreatic cancer cells. RNA interference results showed that CCR6 is a receptor for CCL20 in pancreatic cancer cells, mediating the increased invasive properties of these cells promoted by CCL20. Using a mouse model, we confirmed the roles of CCR6/CCL20 in promoting pancreatic cancer growth and liver metastasis in vivo Our findings provide insight into the important role of macrophage-secreted CCL20 in pancreatic cancer and implicate CCR6/CCL20 as potential therapeutic targets.

TLR2 promotes human intrahepatic cholangiocarcinoma cell migration and invasion by modulating NF-κB pathway-mediated inflammatory responses.

Intrahepatic cholangiocarcinoma (ICC) is a rare and aggressive malignancy that is often diagnosed at advanced stages, which limits treatment options. Despite its increasing incidence and mortality worldwide, the pathogenesis of ICC is not well understood. Here, we examined the effect of the dysregulation of innate immune responses on carcinogenesis by investigating the role of toll-like receptor (TLR)2 in the pathogenesis and invasiveness of ICC and explored the underlying mechanisms. Immunohistochemical analysis, real-time PCR, and western blotting showed higher TLR2 levels in ICC tissues and cell lines. Silencing and overexpression experiments indicated that TLR2 promotes ICC migration and invasion, induces the expression of epithelial-to-mesenchymal transition (EMT) markers, and upregulates the proinflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1ß concomitant with the activation of NF-κB signaling. Inhibition of NF-κB activity abolished the effect of TLR2 on EMT, invasion and migration, and the TLR2-induced upregulation of proinflammatory cytokines, and suppressed the effect of exogenous TNF-α and IL-6 on restoring EMT, migration and invasion in the presence of TLR2. Taken together, our results indicate that TLR2 has protumorigenic and prometastatic effects in ICC through the upregulation of inflammatory cytokines induced by the activation of NF-κB signaling, suggesting potential novel therapeutic targets for the treatment of ICC.

Overexpression of Phosphoserine Aminotransferase 1 (PSAT1) Predicts Poor Prognosis and Associates with Tumor Progression in Human Esophageal Squamous Cell Carcinoma.

BACKGROUND/AIMS: Phosphoserine aminotransferase 1 (PSAT1) is over-expressed in many carcinoma tissues, however little is known regarding its expression and function in esophageal carcinogenesis. This study investigated the expression of PSAT1 in human esophageal squamous cell carcinoma (ESCC) tissues to determine the relationship between PSAT1 expression and clinicopathological factors. METHODS: The expression of PSAT1 in 64 surgical resections from esophageal carcinogenesis patients was examined by quantitative RT-PCR and immunohistochemistry and the results were compared with clinicopathological factors. In vitro experiments were performed in ESCC cells overexpressing PSAT1 to measure cell viability and invasion. Tumor formation in vivowas examined by injection of tumor cells into immunocompromised mice subcutaneously. RESULTS: PSAT1 expression was elevated in ESCC tissues compared to normal esophageal tissues. Increased PSAT1 expression was significantly associated with stage of disease, lymph node metastasis, distant metastasis and poor prognosis. In vitro, PSAT1 overexpression promoted ESCC cell proliferation and matrigel invasion. In vivo, injection of mice with ECSS cells overexpressing PSAT1 enhanced tumor formation. Western blot analysis revealed that PSAT1 upregulated the expression and/or activity of GSK3ß/Snail. CONCLUSION: PSAT1 plays a crucial role in the development of ESCC and predicts poor survival. Therefore, PSAT1 may be a promising novel anticancer therapeutic target.

MicroRNA-340 Inhibits Esophageal Cancer Cell Growth and Invasion by Targeting Phosphoserine Aminotransferase 1.

BACKGROUND/AIMS: Emerging evidence indicates that microRNA (miR)-340 is downregulated in various human cancers, suggesting that it acts as a tumor suppressor. The aim of the present study was to evaluate the expression and role of miR-340 in human esophageal squamous cell carcinoma (ESCC). METHODS: The expression of miR-340 was examined in 64 paired ESCC and adjacent non-tumor tissues by quantitative real time PCR. The effects of miR-340 on ESCC cell proliferation and metastasis were examined by MTT and Matrigel invasion assays. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice. Targets of miR-340 were identified by bioinformatics and verified by luciferase reporter assays, quantitative real-time PCR, and western blotting. RESULTS: MiR-340 was significantly downregulated in ESCC tumor tissues compared to adjacent non-tumor tissues and in ESCC cell lines compared to esophageal endothelial cells. Overexpression of miR-340 inhibited ESCC cell growth, colony formation, and invasion, and tumor growth in a xenograft mouse model. PSAT1 was identified as a direct target of miR-340 and its ectopic expression partially reversed the miR-340 mediated inhibition of viability, invasion and EMT in ESCC cells. The expression of miR-340 was negatively correlated with that of PSAT1 in human ESCC samples. CONCLUSION: MiR-340 functions as a tumor suppressor by modulating the expression of PSAT1 and may contribute to the progression and invasiveness of ESCC.

Percutaneous needle decompression in treatment of malignant small bowel obstruction.

AIM: To investigate the efficacy and safety of percutaneous needle decompression in the treatment of malignant small bowel obstruction (MSBO). METHODS: A prospective analysis of the clinical data of 52 MSBO patients undergoing percutaneous needle decompression was performed. RESULTS: Percutaneous needle decompression was successful in all 52 patients. Statistically significant differences were observed in symptoms such as vomiting, abdominal distension and abdominal pain before and after treatment (81.6% vs 26.5%, 100% vs 8.2%, and 85.7% vs 46.9%, respectively; all P < 0.05). The overall significantly improved rate was 19.2% (11/52) and the response rate was 94.2% (49/52) using decompression combined with nasal tube placement, local arterial infusion of chemotherapy and nutritional support. During the one-month follow-up period, puncture-related complications were acceptable. CONCLUSION: Percutaneous needle intestinal decompression is a safe and effective palliative treatment for MSBO.