Objective To investigate the effects of microRNA497 (miR-497) on the metastasis of gastric cancer and its possible molecular mechanism. Methods SGC-7901 gastric cancer parent cells were cultured in an ultra-low adhesion environment, and the anoikis resistance model of SGC-7901 cells was created after re-adhesion. Clone formation assay, flow cytometry, Transwell^TM test and scratch healing test were used to detect the differences of biological behavior compared with their parent cells. Fluorescence quantitative PCR was performed to detect the expression of miR-497. Western blot analysis was used to detect the changes of key proteins of Wnt/β-catenin signaling pathway and epithelial mesenchymal transformation (EMT) related proteins such as vimentin and E-cadherin. Parent cells and anoikis resistant SGC-7901 cells were transfected with miR-497 inhibitor or miR-497 mimic, and CCK-8 assay was used to detect the proliferation activity. Transwell^TM invasion assay was performed to detect the invasion ability of cells. Transwell^TM migration test and scratch healing assay was used to determine the migration ability. Western blot analysis was used to detect the expressions of Wnt1, β-catenin, vimentin and E-cadherin. By transfecting miR-497 mimic into the anoikis resistance SGC-7901 cells and inoculating them subcutaneously in nude mice, the changes in the volume and mass of tumor tissues were measured and recorded. Western blot analysis was used to determine the expressions of Wnt1, β-catenin, vimentin and E-cadherin of tumor tissues. Results Compared with the parent cells, the anoikis resistance SGC-7901 gastric cancer cells had faster proliferation rate, stronger colony formation, lower apoptosis rate, stronger invasion and migration ability. The expression of miR-497 was significantly decreased. After down-regulation of miR-497, the proliferation ability, invasion and migration ability were significantly enhanced. The expressions of Wnt1, β-catenin and vimentin increased significantly, while E-cadherin decreased notably. The results of up-regulation miR-497 were the opposite. The tumor growth rate, tumor volume and mass of miR-497 overexpression group were significantly lower than those of control group. The expressions of Wnt1, β-catenin and vimentin decreased significantly, while the expression of E-cadherin increased significantly. Conclusion The expression of miR-497 is low in the anoikis resistance SGC-7901 cells. miR-497 can inhibit the growth and metastasis of gastric cancer cells by blocking Wnt/β-catenin signaling pathway and EMT.
Animals ; Mice ; Humans ; beta Catenin/metabolism* ; MicroRNAs/metabolism* ; Vimentin/metabolism* ; Stomach Neoplasms/pathology* ; Anoikis/genetics* ; Wnt Signaling Pathway/genetics* ; Mice, Nude ; Cell Proliferation/genetics* ; Cadherins/genetics* ; Cell Line, Tumor ; Epithelial-Mesenchymal Transition/genetics* ; Cell Movement/genetics*

As an important part of tumor microenvironment, neutrophils are poorly understood due to their spatiotemporal heterogeneity in tumorigenesis. Here we defined, at single-cell resolution, CD44-CXCR2- neutrophils as tumor-specific neutrophils (tsNeus) in both mouse and human gastric cancer (GC). We uncovered a Hippo regulon in neutrophils with unique YAP signature genes (e.g., ICAM1, CD14, EGR1) distinct from those identified in epithelial and/or cancer cells. Importantly, knockout of YAP/TAZ in neutrophils impaired their differentiation into CD54+ tsNeus and reduced their antitumor activity, leading to accelerated GC progression. Moreover, the relative amounts of CD54+ tsNeus were found to be negatively associated with GC progression and positively associated with patient survival. Interestingly, GC patients receiving neoadjuvant chemotherapy had increased numbers of CD54+ tsNeus. Furthermore, pharmacologically enhancing YAP activity selectively activated neutrophils to suppress refractory GC, with no significant inflammation-related side effects. Thus, our work characterized tumor-specific neutrophils in GC and revealed an essential role of YAP/TAZ-CD54 axis in tsNeus, opening a new possibility to develop neutrophil-based antitumor therapeutics.
Humans ; Animals ; Mice ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Stomach Neoplasms/pathology* ; Neutrophils/pathology* ; Signal Transduction/genetics* ; YAP-Signaling Proteins ; Tumor Microenvironment ; Hyaluronan Receptors/genetics*

OBJECTIVE: To investigate the expression of microRNA miR-431-5p in gastric cancer (GC) tissues and its effects on apoptosis and mitochondrial function in GC cells. METHODS: The expression level of miR-431-5p in 50 clinical samples of GC tissues and paired adjacent tissues was detected using real-time fluorescence quantitative PCR, and its correlation with the clinicopathological features of the patients was analyzed. A cultured human GC cell line (MKN-45 cells) were transfected with a miR-431-5p mimic or a negative control sequence, and the cell proliferation, apoptosis, mitochondrial number, mitochondrial potential, mitochondrial permeability transition pore (mPTP), reactive oxygen species (ROS) production and adenosine triphosphate (ATP) content were detected using CCK-8 assay, flow cytometry, fluorescent probe label, or ATP detection kit. The changes in the expression levels of the apoptotic proteins in the cells were detected with Western blotting. RESULTS: The expression level of miR-431-5p was significantly lower in GC tissues than in the adjacent tissues (P < 0.001) and was significantly correlated with tumor differentiation (P=0.0227), T stage (P=0.0184), N stage (P=0.0005), TNM stage (P=0.0414) and vascular invasion (P=0.0107). In MKN-45 cells, overexpression of miR-431-5p obviously inhibited cell proliferation and induced cell apoptosis, causing also mitochondrial function impairment as shown by reduced mitochondrial number, lowered mitochondrial potential, increased mPTP opening, increased ROS production and reduced ATP content. Overexpression of miR-431-5p significantly downregulated the expression of Bcl-2 and increased the expressions of pro-apoptotic proteins p53, Bcl-2 and cleaved caspase-3 protein. CONCLUSION The expression of miR-431-5p is down-regulated in GC, which results in mitochondrial function impairment and promotes cell apoptosis by activating the Bax/Bcl-2/caspase3 signaling pathway, suggesting the potential role of miR-431-5p in targeted therapy for GC.
Humans ; Apoptosis/genetics* ; bcl-2-Associated X Protein ; Caspase 3 ; Cell Line, Tumor ; Cell Proliferation/genetics* ; MicroRNAs/metabolism* ; Mitochondria/metabolism* ; Mitochondrial Permeability Transition Pore ; Reactive Oxygen Species ; Stomach Neoplasms/pathology*

OBJECTIVES: Gastric cancer is a common cancer of the digestive system. Long non-coding RNA (lncRNA) plays an important role in the formation and development of gastric cancer. This study aims to investigate the effect of long non-coding lncRNA 114227 on biologic behaviors in gastric cancer cells. METHODS: The experiment was divided into 4 groups: a negative control (NC) group, a lncRNA 114227 small interference (si-lncRNA 114227) group, an empty vector (Vector) group, and an overexpression vector (OE-lncRNA 114227) group. The expressions of lncRNA 114227 in gastric mucosa and gastric cancer tissues, gastric mucosal epithelial cells and different gastric cancer strains were determined by real-time reverse transcription PCR (real-time RT-PCR).The proliferation were detected by CCK-8 assay in gastric cancer cells. The epithelial-mesenchymal transformation (EMT) was utilized by Transwell assay, scratch healing assay, and Western blotting in gastric cancer cells. The effect of lncRNA 114227 on proliferation of gastric cancer cells was detected by tumor bearing experiment in nude mice in vivo. RESULTS: The expression level of lncRNA 114227 in the gastric cancer tissues was significantly lower than that in the gastric mucosa tissues, and in 4 kinds of gastric cancer strains was all significantly lower than that in gastric mucosal epithelial cells (all P<0.01). In vitro, the proliferation and migration abilities of gastric cells were significantly reduced after overexpressing lncRNA 114227, and cell proliferation and migration were enhanced after silencing lncRNA 114227 (all P<0.05). The results of in vivo subcutaneous tumorigenesis in nude mice showed that the tumorigenic volume of the tumor-bearing mice in the OE-lncRNA 114227 group was significantly smaller than that of the Vector group, and the tumorigenic quality was lower than that of the Vector group (P<0.05), indicating that lncRNA 114227 inhibited tumorigenesis. CONCLUSIONS The expression of lncRNA 114227 is downregulated in gastric cancer gastric cancer tissues and cell lines. LncRNA 114227 may inhibit the proliferation and migration of gastric cancer cells through EMT process.
Animals ; Mice ; RNA, Long Noncoding/metabolism* ; Stomach Neoplasms/pathology* ; Mice, Nude ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Carcinogenesis/genetics* ; Cell Movement/genetics* ; Epithelial-Mesenchymal Transition/genetics* ; Gene Expression Regulation, Neoplastic ; Apoptosis/genetics*

Objective: To investigate the molecular mechanism of how lactate induces high mobility group box 1 (HMGB1) release. Methods: Gastric cancer HGC-27 cells were divided into the control group and the lactate group (The cells were treated with lactate for 6 h). The level of HMGB1 in the cell culture medium was detected by enzyme-linked immunosorbent assay (ELISA), the localization of HMGB1 was detected using laser confocal microscopy, and the nuclear translocation of HMGB1 was detected using the nucleoplasmic separation assay. The phosphorylation and acetylation levels of HMGB1 were determined by co-immunoprecipitation, and Western blot was used to measure the phosphorylation of Akt and protein kinase C (PKC). HGC-27 cells were first treated with lactate and LY294002, the inhibitor of Akt, and then the phosphorylation of HMGB1 and Akt was analyzed by co-immunoprecipitation and Western blot, respectively. The localization of HMGB1 in cells was detected by laser confocal microscopy. EdU and Transwell assays were used to detect the proliferation and migration abilities of HGC-27 cells, respectively. HGC-27 cells were then injected into the BALB/C null mice for subcutaneous tumor implantation. Mice in the lactate group were intraperitoneally injected with lactate (0.2 g/kg/2 d), while those in the control group were intraperitoneally injected with an equal amount of PBS for 20 consecutive days. ELISA was used to detect the HMGB1 levels in the blood samples taken from the medial canthus vein of the mice, while co-immunoprecipitation and Western blot were used to detect the phosphorylation of HMGB1 and Akt in tumor tissue proteins, respectively. Results: The release levels of HMGB1 in the lactate group were (2 995.00±660.91) pg/ml and (696.33±22.03) pg/ml, after lactate treatment for 6 h and 12 h, respectively, both higher than those in the control group (485.00±105.83) pg/ml (P<0.001 and P=0.028, respectively). After lactate treatment for 6 h, the relative expression of HMGB1 protein in the cytoplasm of HGC-27 cells was 1.13±0.09, higher than that of the control group (0.83±0.07, P=0.001), while the relative expression of HMGB1 in the nucleus was 0.79±0.06, lower than that of the control group (1.07±0.06, P=0.007). The phosphorylation level of HMGB1 reached 1.41±0.09, which was higher than that of the control group (0.97±0.10, P=0.031). The phosphorylation level of Akt was 11.16±0.06, higher than that of the control group (0.91±0.022, P=0.002). The phosphorylation level and nuclear translocation of HMGB1 induced by lactate decreased obviously after Akt inhibition; the proliferation and migration abilities induced by lactate were also obviously inhibited after Akt inhibition. In vivo, the HMGB1 level in the peripheral blood was (1 280.70±389.66) pg/ml in the lactate group, which was obviously higher than that in the control group (595.11±44.75) pg/ml (P=0.008), and the phosphorylation levels of HMGB1 and Akt in tumor tissues in the lactate group were obviously enhanced compared with the control group. Conclusion: Lactate induces HMGB1 release through enhancing HMGB1 phosphorylation via the Akt signaling pathway.
Mice ; Animals ; Stomach Neoplasms/pathology* ; Proto-Oncogene Proteins c-akt/metabolism* ; HMGB1 Protein/metabolism* ; Phosphorylation ; Lactic Acid ; Mice, Inbred BALB C ; Signal Transduction

Objective: To investigate the molecular mechanism of how lactate induces high mobility group box 1 (HMGB1) release. Methods: Gastric cancer HGC-27 cells were divided into the control group and the lactate group (The cells were treated with lactate for 6 h). The level of HMGB1 in the cell culture medium was detected by enzyme-linked immunosorbent assay (ELISA), the localization of HMGB1 was detected using laser confocal microscopy, and the nuclear translocation of HMGB1 was detected using the nucleoplasmic separation assay. The phosphorylation and acetylation levels of HMGB1 were determined by co-immunoprecipitation, and Western blot was used to measure the phosphorylation of Akt and protein kinase C (PKC). HGC-27 cells were first treated with lactate and LY294002, the inhibitor of Akt, and then the phosphorylation of HMGB1 and Akt was analyzed by co-immunoprecipitation and Western blot, respectively. The localization of HMGB1 in cells was detected by laser confocal microscopy. EdU and Transwell assays were used to detect the proliferation and migration abilities of HGC-27 cells, respectively. HGC-27 cells were then injected into the BALB/C null mice for subcutaneous tumor implantation. Mice in the lactate group were intraperitoneally injected with lactate (0.2 g/kg/2 d), while those in the control group were intraperitoneally injected with an equal amount of PBS for 20 consecutive days. ELISA was used to detect the HMGB1 levels in the blood samples taken from the medial canthus vein of the mice, while co-immunoprecipitation and Western blot were used to detect the phosphorylation of HMGB1 and Akt in tumor tissue proteins, respectively. Results: The release levels of HMGB1 in the lactate group were (2 995.00±660.91) pg/ml and (696.33±22.03) pg/ml, after lactate treatment for 6 h and 12 h, respectively, both higher than those in the control group (485.00±105.83) pg/ml (P<0.001 and P=0.028, respectively). After lactate treatment for 6 h, the relative expression of HMGB1 protein in the cytoplasm of HGC-27 cells was 1.13±0.09, higher than that of the control group (0.83±0.07, P=0.001), while the relative expression of HMGB1 in the nucleus was 0.79±0.06, lower than that of the control group (1.07±0.06, P=0.007). The phosphorylation level of HMGB1 reached 1.41±0.09, which was higher than that of the control group (0.97±0.10, P=0.031). The phosphorylation level of Akt was 11.16±0.06, higher than that of the control group (0.91±0.022, P=0.002). The phosphorylation level and nuclear translocation of HMGB1 induced by lactate decreased obviously after Akt inhibition; the proliferation and migration abilities induced by lactate were also obviously inhibited after Akt inhibition. In vivo, the HMGB1 level in the peripheral blood was (1 280.70±389.66) pg/ml in the lactate group, which was obviously higher than that in the control group (595.11±44.75) pg/ml (P=0.008), and the phosphorylation levels of HMGB1 and Akt in tumor tissues in the lactate group were obviously enhanced compared with the control group. Conclusion: Lactate induces HMGB1 release through enhancing HMGB1 phosphorylation via the Akt signaling pathway.
Mice ; Animals ; Stomach Neoplasms/pathology* ; Proto-Oncogene Proteins c-akt/metabolism* ; HMGB1 Protein/metabolism* ; Phosphorylation ; Lactic Acid ; Mice, Inbred BALB C ; Signal Transduction

Objective: To investigate the levels of Th9 cells and interleukin-9 (IL-9), and to assess the regulatory activity of Th9/IL-9 to anti-tumor immune response in patients with gastric cancer. Methods: Thirty-four patients with gastric cancer who received operation in the First Affiliated Hospital of Xinxiang Medical University between October 2018 and August 2019 were included. Twenty individuals who received physical examination in the same period were also enrolled. Peripheral blood was collected, and then plasma and peripheral blood mononuclear cells (PBMCs) were isolated. Tumor-infiltrating lymphocytes (TILs) and autologous gastric cancer cells were isolated from resected gastric cancer tissues. CD4(+) T cells, CD8(+) T cells, and CD4(+) CCR4(-)CCR6(-)CXCR3(-) cells were purified from PBMCs and TILs. Plasma IL-9 level was measured by enzyme linked immunosorbent assay (ELISA). The percentage of CD3(+) CD4(+) IL-9(+) Th9 cells in PBMCs and TILSs was assessed by flow cytometry. The mRNA levels of IL-9 and transcriptional factors purine-rich nucleic acid binding protein 1 (PU.1) were semi-quantified by real-time quantitative polymerase chain reaction (RT-qPCR). PBMCs and TILs from gastric cancer patients were stimulated with recombinant human IL-9. Cellular proliferation was measured by cell counting kit-8. The phosphorylation levels of signal transducer and activator of transcription 3 (STAT3) and STAT6 were investigated by western blot. Cytokine production was measured by ELISA. Purified CD8(+) T cells from TILs of gastric cancer patients were stimulated with recombinant human IL-9. CD8(+) T cells and autologous gastric cancer cells were cocultured in direct contact and indirect contact manner. The percentage of target cell death was calculated by measuring the lactate dehydrogenase (LDH) level. These cretion of γ-Interferon (γ-IFN) and tumor necrosis factor-α (TNF-α) was measured by ELISA. CD4(+) CCR4(-)CCR6(-)CXCR3(-)cells, CD8(+) T cells, and autologous gastric cancer cells were directly cocultured, and anti-IL-9 neutralizing antibody was added. The target cell death was measured. Results: The percentages of CD3(+) CD4(+) IL-9(+) Th9 cells in PBMCs of control group and PBMCs of gastric cancer group were (1.21±0.25)% and (1.14±0.19)%, respectively. The difference was not statistically significant (P=0.280). The percentage of CD3(+) CD4(+) IL-9(+) Th9 cells in TILs of gastric cancer group was (2.30±0.55)%, which was higher than those in PBMCs of control group and PBMCs of gastric cancer group (P<0.001). The plasma IL-9 level in control group and gastric cancer group were (5.04±1.51) and (4.93±1.25) ng/ml. The difference was not statistically significant (P=0.787). The relative levels of IL-9 mRNA in PBMCs of control group and PBMCs of gastric cancer group were 1.33±0.39 and 1.36±0.27. The difference was not statistically significant (P=0.691). The relative level of IL-9 mRNA in TILs of gastric cancer group was 2.90±0.75, which was higher than those in PBMCs of control group (P<0.001) and PBMCs of gastric cancer group (P<0.001). The relative levels of PU.1 mRNA in PBMCs of control group and PBMCs of gastric cancer group were 1.21±0.12 and 1.20±0.11. The difference was not statistically significant (t=0.21, P=0.833). PU.1 mRNA relative level in TILs of gastric cancer group was 2.81±0.65, which was higher than those in PBMCs of control group (P<0.001) and PBMCs of gastric cancer group (P<0.001). Recombinant human IL-9 stimulation did not affect the proliferation of PBMCs and TILs of gastric cancer patients (P>0.05), but elevated the phosphorylation level of STAT6 and induced the secretions of γ-IFN, IL-17, and IL-22 by TILs (P<0.05). In direct contact culture system, IL-9 stimulation promoted tumor-infiltrating CD8(+) T cells-induced autologous gastric cancer cell death [(20.62±2.27)% vs. (16.08±2.61)%, P<0.01)]. In indirect contact culture system, IL-9 stimulation did not increase CD8(+) T cell-induced autologous gastric cancer cell death [(5.21±0.70)% vs. (5.31±1.22)%, P=0.998)]. However, the secretion levels of γ-IFN were elevated in response to IL-9 stimulation in both culture systems [direct contact culture system: (100.40±12.05) pg/ml vs. (76.45±8.56) pg/ml; indirect contact culture system: (78.00±9.98) pg/ml vs. (42.09±10.71) pg/ml; P<0.01]. The TNF-α secretion level did not significantly changed (P>0.05). In direct contact culture system, the percentage of target cells was (22.01±3.05) % and γ-IFN secretion level was (104.5±12.84) pg/ml in CD4(+) CCR4(-)CCR6(-)CXCR3(-) cells+ CD8(+) T cells+ gastric cancer cells group, which was higher than (16.08±2.61)% and (76.45±8.56) pg/ml in CD8(+) T cells+ gastric cancer cells group (P<0.01). However, the percentage of target cells was (14.47±3.14)% and γ-IFN secretion level was (70.45±19.43) pg/ml in CD4(+) CCR4(-)CCR6(-)CXCR3(-) cells+ CD8(+) T cells+ gastric cancer cells+ anti-IL-9 neutralizing antibody group, which were lower than those in CD4(+) CCR4(-)CCR6(-)CXCR3(-) cells+ CD8(+) T cells+ gastric cancer cells group (P<0.01). Conclusion: Tumor-infiltrating Th9 cells and the secreting IL-9 promote the activity of CD8(+) T cells in gastric cancer patients, and enhance anti-tumor immune response.
Humans ; CD8-Positive T-Lymphocytes ; Stomach Neoplasms/pathology* ; Tumor Necrosis Factor-alpha/metabolism* ; Lymphocytes, Tumor-Infiltrating/pathology* ; Interferon-gamma/metabolism* ; RNA, Messenger/metabolism* ; Antibodies, Neutralizing/metabolism*

Adenocarcinoma/pathology* ; Humans ; Stomach Neoplasms/pathology* ; Tumor Suppressor Protein p53/metabolism*

Objective: To analyze density of stromal tumor-infiltrating lymphocytes (sTIL) and expression of lymphocyte-activation gene-3 (LAG-3) protein in advanced gastric adenocarcinomas, and to investigate the correlation of sTIL and LAG-3 with the prognosis in patients with advanced gastric adenocarcinoma. Methods: The clinicopathological characteristics and follow-up data of 260 patients with advanced gastric adenocarcinoma were collected at Fujian Cancer Hospital, from January 2011 to December 2014. The percentage of sTILs was reported semi-quantitatively using histological section evaluation, the LAG-3 protein was detected using immunohistochemistry, and the expression was correlated with the clinicopathological features and patient outcomes. Results: Among the 260 cases, high density of sTIL was detected in 173 cases (66.5%) while LAG-3 high expression was observed in 160 cases (61.5%). These cases were divided into four groups. Group Ⅰ: 48 cases (18.5%) were sTIL low/LAG-3 low; group Ⅱ: 52 cases (20.0%) were sTIL high/LAG-3 low; group Ⅲ: 39 cases (15.0%) were sTIL low/LAG-3 high; group Ⅳ: 121 cases (46.5%) were sTIL high/LAG-3 high. Kaplan-Meier survival analyses showed that patient prognoses were related to age, tumor size, tumor location, Lauren classification, perineural invasion, vascular invasion, TNM staging, postoperative adjuvant chemotherapy and molecular classification (P<0.05). Meanwhile, higher densities of sTIL and higher expression of LAG-3 were associated with better prognosis. Multivariate survival analysis showed age, tumor size, Lauren classification and postoperative adjuvant chemotherapy were independent prognostic factors for patient survival. The results showed a poor prognosis in low-sTIL/low-LAG-3 patients. Conclusions: Compared with low density of sTIL and low expression of LAG-3, high density of sTIL and high expression of LAG-3 are associated with better outcomes in patients with advanced gastric adenocarcinoma, respectively. Combined detecton of sTIL and LAG-3 may be more useful in gastric cancer than using either alone. Age, tumor size, Lauren classification and postoperative adjuvant chemotherapy are independent prognostic factors for patients with advanced gastric adenocarcinoma.
Adenocarcinoma/pathology* ; Humans ; Immunohistochemistry ; Lymphocytes, Tumor-Infiltrating/metabolism* ; Neoplasm Staging ; Prognosis ; Retrospective Studies ; Stomach Neoplasms/pathology*

OBJECTIVE: To investigate the expression of circPCSK5 in gastric cancer (GC) and its role in regulation of the proliferation, invasion and epithelial-mesenchymal transition (EMT) of GC cells. METHODS: High-throughput sequencing was performed in 3 pairs of GC and adjacent gastric mucosa tissues to obtain the differential expression profile of circRNA. The expression of circPCSK5 was detected in 62 patients undergoing radical surgery for GC using RT-qPCR, and the correlation between circPCSK5 expression level and clinicopathological data of the patients was analyzed. The overall survival and disease-free survival of the patients were assessed with Kaplan-Meier survival analysis, and the independent risk factors affecting the patients' prognosis were analyzed using Cox proportional hazards regression model. The stability and subcellular localization of circPCSK5 were assessed using RNase R and actinomycin D assays, fluorescence in situ hybridization and nucleocytoplasmic separation assay. CCK-8 assay, EdU assay and Transwell assay were employed to examine the changes in proliferation, migration and invasion of GC cells with circPCSK5 knockdown or overexpression; Western blotting and RT-qPCR assays were used to detect the expression levels of EMT markers in the transfected cells. RESULTS: The expression of circPCSK5 was significantly upregulated in GC tissues and cells (P < 0.001, P < 0.01). The expression level of circPCSK5 was positively correlated with tumor size, vascular invasion, lymph node metastasis and AJCC stage of GC (P < 0.05). The overall survival and disease-free survival were significantly lower in GC patients with high circPCSK5 expression than in those with low circPCSK5 expression (P < 0.001). High circPCSK5 expression was an independent risk factor for a poor prognosis of GC patients (P < 0.05). Knockdown of circPCSK5 significantly inhibited the proliferation, migration and invasion of HGC27 cells (P < 0.01), increased the expressions of E-cadherin, and decreased the expression of N-cadherin and vimentin (P < 0.01). CircPCSK5 overexpression promoted the proliferation, migration and invasion of MKN45 cells (P < 0.01), reduced E-cadherin expression and increased N-cadherin and vimentin expressions (P < 0.01). CONCLUSION CircPCSK5 is highly expressed in GC and promotes the proliferation, invasion and EMT of GC cells, suggesting its potential as a prognostic biomarker and therapeutic target for GC.
Humans ; Epithelial-Mesenchymal Transition/genetics* ; Stomach Neoplasms/pathology* ; Vimentin/metabolism* ; Neoplasm Invasiveness/genetics* ; In Situ Hybridization, Fluorescence ; Cell Movement/genetics* ; Gene Expression Regulation, Neoplastic ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Cadherins/metabolism*