Ertao Zhai

Autocrine VEGF signaling promotes cell proliferation through a PLC-dependent pathway and modulates Apatinib treatment efficacy in gastric cancer.

Background Tumor cells produce vascular endothelial growth factor (VEGF) which interact with the membrane or cytoplasmic VEGF receptors (VEGFRs) to promote cell growth in an angiogenesis-independent fashion. Apatinib, a highly selective VEGFR2 inhibitor, is the only effective drug for patients with terminal gastric cancer (GC) who have no other chemotherapeutic options. However, its treatment efficacy is still controversy and the mechanism behind remains undetermined. In this study, we aimed to investigate the role of autocrine VEGF signaling in the growth of gastric cancer cells and the efficacy of Apatinib treatment. Methods The expression of phosphor VEGFR2 in gastric cancer cell lines was determined by real-time PCR, immunofluorescence, and Western blot. The gastric cancer cells were administrated with or without recombination human VEGF (rhVEGF), VEGFR2 neutralizing antibody, U73122, SU1498, and Apatinib. The nude mice were used for xenograft tumor model. Results we found that autocrine VEGF induced high VEGFR2-expression, promoted phosphorylation of VEGFR2, and further enhanced internalization of pVEGFR2 in gastric cancer cells. The autocrine VEGF was self-sustained through increasing VEGF mRNA and protein expression. It exerted pro-proliferative effect through a PLC-ERK1/2 dependent pathway. Furthermore, we demonstrated that in VEGFR2 overexpressing gastric cancer cells, Apatinib inhibited cell proliferation in vitro and delayed xenograft tumor growth in vivo. However, these effects were not observed in VEGFR2 low expressing gastric cancer cells. Conclusion These results suggested that autocrine VEGF signaling promotes gastric cancer cell proliferation and enhances Apatinib treatment outcome in VEGFR2 overexpression gastric cancer cells both in vitro and in vivo. This study would enable better stratification of gastric cancer patients for clinical treatment decision.

Up-regulation of long non-coding RNA XLOC_010235 regulates epithelial-to-mesenchymal transition to promote metastasis by associating with Snail1 in gastric cancer

We previously performed long non-coding RNA (lncRNA) expression microarray analyses to identify novel indicators for gastric cancer (GC) metastasis and prognosis in which we identified lncRNA XLOC_010235 (XLOC) as a candidate RNA. However, XLOC_010235 molecular mechanism of action remains unclear. Gain and loss of function approaches were used to investigate the biological role of XLOC in vitro. The effects of XLOC on cell viability were assessed by CCK-8 proliferation assays. Real-time PCR, western-blot and immunofluorescence were used to evaluate the mRNA and protein expression of Snail and multiple EMT related molecules. The positive XLOC/Snail1 interaction was identified and verified by immunohistochemistry assay and bivariate correlation analysis. Ectopic expression of XLOC facilitate cell viability, migration and invasion, leading to the acceleration of metastasis, while depletion of XLOC expression hindered cell migration and invasion. Moreover, over-expression of XLOC was found to play a important role in epithelial-to-mesenchymal transition (EMT) through the regulation of E-cadherin, N-cadherin and Vimentin expression, in which transcriptional factor Snail1 was involved. These results advance our understanding of the role of lncRNA XLOC_010235 as a active regulator of EMT by associating with Snail1, which may help in the development of new therapeutics.

VEGF promotes gastric cancer development by upregulating CRMP4

This study aimed to investigate the precise role of CRMP4 in gastric tumor growth and patient survival. The mRNA and protein expression levels of CRMP4, VEGF and VEGFR2 were validated by qRT-PCR and immunohistochemistry. We investigated the effects on tumor growth of overexpression and knockdown of CRMP4 both in vitro and in vivo by constructing stable gastric cell lines using lentiviral-mediated transduction and shRNA interference-mediated knockdown of CRMP4 expression. We further validated the role of the ERK/AKT signaling pathways in VEGF and CRMP4 expression using ERK and PI3K inhibitors. Increased expression of VEGF and CRMP4 were observed in gastric cancer tissues compared with tumor-adjacent tissue. We found that higher CRPM4 expression was associated with lymph node metastasis, TNM stage, tumor differentiation and poorer prognosis in gastric cancer patients. In HGC27 and SGC7901 gastric cancer cells, VEGF upregulated CRMP4 in time and dose-dependent manners. Overexpression of CRMP4 increased cell proliferation, migration and invasion, whereas knockdown of CRMP4 expression had opposite effects. VEGF activated CRMP4 expression in gastric cancer cells, and this effect was significantly inhibited by MAPK and PI3K inhibitors (PD98059 and LY294002). In mice, CRMP4 overexpression also resulted in increased tumor growth. These results suggest that increased CRMP4 expression mediated by the activation of VEGF signaling facilitates gastric tumor growth and metastasis, which may have clinical implications associated with a reduced survival rate in gastric cancer patients.

Stress-inducible Protein-1 promotes metastasis of gastric cancer via Wnt/β-catenin signaling pathway

BackgroundStress-Inducible Protein-1 (STIP1) is a co-chaperone that associates directly with heat shock proteins, and regulates motility of various types of cancer. In the present study, we investigated the role of STIP1 on metastasis of gastric cancer (GC).MethodsIn vivo metastatic experimental model was employed to investigate the effect of STIP1 on metastasis of GC cells. Loss-of-function and gain-of-function experiments were performed to examine the role of STIP1 on metastasis of GC cells. Western blot, immunofluorescence staining, migration and invasion assays, microarray and KEGG pathway analysis were applied to explore the underlying mechanism.ResultsIn current study, we demonstrated that STIP1 promoted lung metastasis of GC cells in vivo. Furthermore, STIP1 significantly enhanced migration and invasion abilities of GC cells. In contrast, knock-down of STIP1 yielded the opposite effects on these phenotypes in vitro. STIP1 promoted tumor metastasis through inducing epithelial-to-mesenchymal transition in GC cells. Mechanistically, STIP1 promoted GC metastasis via up-regulation of targeted genes in Wnt/β-catenin signaling pathway, including c-Myc and Cyclin D1, and accompanied with nuclear translocation of β-catenin.ConclusionsOur findings indicate that elevated expression of STIP1 exhibited a metastasis-promoting effect in GC cells through activation of Wnt/β-catenin signaling pathway. STIP1 may be served as a potential therapeutic target for preventing GC metastasis.

Systemic immune-inflammation index for predicting prognosis of colorectal cancer

AIM To investigate the clinical significance of preoperative systemic immune-inflammation index (SII) in patients with colorectal cancer (CRC). METHODS A retrospective analysis of 1383 cases with CRC was performed following radical surgery. SII was calculated with the formula SII = (P × N)/L, where P, N, and L refer to peripheral platelet, neutrophil, and lymphocyte counts, respectively. The clinicopathological features and follow-up data were evaluated to compare SII with other systemic inflammation-based prognostic indices such as the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) in patients with CRC. RESULTS The optimal cut-off point for SII was defined as 340. The overall survival (OS) and disease-free survival (DFS) were better in patients with low NLR, PLR, and SII (P < 0.05). The SII was an independent predictor of OS and DFS in multivariate analysis. The area under the receiver-operating characteristics (ROC) curve for SII (0.707) was larger than those for NLR (0.602) and PLR (0.566). In contrast to NLR and PLR, SII could effectively discriminate between the TNM subgroups. CONCLUSION SII is a more powerful tool for predicting survival outcome in patients with CRC. It might assist the identification of high-risk patients among patients with the same TNM stage.

HSP70/HSP90-Organizing Protein Contributes to Gastric Cancer Progression in an Autocrine Fashion and Predicts Poor Survival in Gastric Cancer

Background/Aims: HSP70/HSP90-organizing protein (HOP) is an adaptor protein that mediates heat shock protein 70 (HSP70) and HSP90 folding. HOP can be secreted by cancer cells and promote malignant cell growth in an autocrine manner. Here, we studied its role in gastric cancer (GC). Methods: HOP mRNA and protein levels were detected by quantitative real-time PCR and western blotting, respectively, and enzyme-linked immunosorbent assay was used to determine the serum levels. Immunohistochemistry was performed to analyze HOP expression in 117 GC tissues and 32 adjacent normal tissues. The Cell Counting Kit-8 cell viability assay, flow cytometry, and western blotting were used to analyze the effects of HOP on cell proliferation and apoptosis, and the potential underlying mechanisms. Results: HOP mRNA and protein levels were significantly higher in GC tissues than in normal tissues in our medical center (P< 0.001) and in The Cancer Genome Atlas database (P< 0.001). GC patients had higher serum levels of HOP than age-matched healthy controls (P< 0.001); however, once tumors were removed, serum levels significantly decreased (P< 0.01). In human GC tissues, increased HOP expression was associated with tumor progression and poor survival. Notably, autocrine HOP promoted cell proliferation through the phospholipase Cγ1-extracellular signal-regulated kinase 1/2-dependent pathway, and inhibited cell apoptosis by regulating the activities of caspase 9, caspase 3, and B-cell lymphoma 2. Blocking extracellular HOP with neutralizing antibody reduced proliferation and enhanced fluorouracil-induced apoptosis of GC cells. Conclusions: Our findings demonstrate that HOP is an important molecular marker and prognostic factor for GC, and functionally contributes to tumor cell growth and survival. These results provide a rationale for considering HOP as a potential therapeutic target and chemosensitizer in GC.

Aberrant expression of stress-induced phosphoprotein 1 in colorectal cancer and its clinicopathologic significance

Stress-induced phosphoprotein 1 (STIP1) is an adaptor protein that bridges HSP70 and HSP90 folding and a secretory protein that regulates malignant tumor progression. The aim of the present study was to demonstrate the clinicopathological significance and prognostic role of STIP1 in colorectal cancer (CRC). We used data from The Cancer Genome Atlas (TCGA) to analyze STIP1 expression in CRC and utilized 8 pairs of fresh-frozen tissue samples to investigate STIP1 expression in CRC tissues and adjacent normal tissues using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assays. We also used immunohistochemical staining to detect STIP1 expression in 144 formalin-fixed, paraffin-embedded (FFPE) CRC tissue samples and determine the clinical significance of STIP1 expression in CRC. The results of bioinformatics analysis, qRT-PCR, and Western blot showed that STIP1 expression was higher in CRC tissues than in adjacent normal tissues. High STIP1 expression was significantly correlated with advanced T stage (P = .01), N stage (P = .001), M stage (P < .001), and TNM stage (P < .001). Moreover, Kaplan-Meier analyses indicated that higher STIP1 expression predicted a worse prognosis in patients with CRC, and Cox regression analysis revealed that STIP1 was an independent prognostic factor for overall survival and disease-free survival in patients with CRC. In conclusion, our results suggest that STIP1 acts as an oncogene in CRC and can therefore serve as a biomarker for the prognosis of patients with CRC.

High expression of SLC17A9 correlates with poor prognosis in colorectal cancer

Solute carrier family 17 member 9 (SLC17A9) is a member of the family of transmembrane proteins that are involved in the transport of small molecules. The role of SLC17A9 in colorectal cancer (CRC) remains poorly understood. The present study aimed to demonstrate the clinicopathological significance and prognostic role of SLC17A9 in CRC. Here, we firstly analyzed the data from The Cancer Genome Atlas on SLC17A9 expression in CRC data sets and detected SLC17A9 expression level in 8 pairs of fresh CRC tissues and adjacent nontumorous tissues by quantitative real-time reverse-transcription polymerase chain reaction and Western blotting assays. Immunohistochemical staining was used to detect SLC17A9 protein expression in 144 CRC patients in our center. The bioinformatic analysis, Western blotting, and immunohistochemical analyses revealed that SLC17A9 was significantly up-regulated in CRC specimens compared with adjacent nontumorous tissues. SLC17A9 overexpression was significantly correlated with several clinicopathological features, such as advanced T stage (P < .001), N stage (P < .001), M stage (P < .001), TNM stage (P < .001), and tumor location (P = .01). A Kaplan-Meier survival curve suggested that higher SLC17A9 expression was statistically correlated with poor overall survival and disease-free survival in patients with CRC. Univariate and multivariate Cox regression analyses demonstrated that SLC17A9 was an independent prognostic predictor for survival of CRC patients. Therefore, our data suggested that SLC17A9 may play an important role in the progression of CRC and may potentially be used as an independent biomarker for prognostic evaluation of CRC.

Increased expression of heat shock factor 1 (HSF1) is associated with poor survival in gastric cancer patients

BackgroundHeat shock factor 1 (HSF1) was initially identified as a transcription factor encoding heat shock proteins, which assist in refolding or degrading damaged proteins. Recent studies have reported that HSF1 can act as an oncogene that regulates tumour progression. The present study aimed to elucidate the clinicopathological significance and prognostic value of HSF1 expression in gastric cancer (GC).MethodsThe data from The Cancer Genome Atlas (TCGA) were used to analyse HSF1 expression in GC and normal tissues, while 8 pairs of freshly frozen tissue samples were used to investigate HSF1 expression at the mRNA and protein levels in GC tissues and adjacent normal tissues using quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting assays. The correlations between HSF1 expression and clinicopathological parameters, including the survival rate, were investigated in 117 GC tissue samples by immunohistochemical analysis.ResultsThe results of bioinformatics analysis, qRT-PCR, and western blot showed that HSF1 expression was higher in GC tissues than in normal tissues. High HSF1 expression was found in 54.7% (64/117) patients. Patients with high HSF1 expression had larger tumour size (P = 0.001), advanced Bornmann classification (P = 0.002), advanced depth of invasion (P = 0.015), lymph node metastasis (P<0.001), distant metastasis (P = 0.011) and tumour-node-metastasis (P<0.001). Moreover, the Kaplan-Meier and Cox proportional hazards analyses indicated that high HSF1 expression was significantly associated with poor overall survival and recurrence-free survival in GC patients and that high HSF1 expression was an independent prognostic factor for the long-term survival in GC patients.ConclusionsTaken together, our results show that high HSF1 expression is significantly correlated with advanced tumour progression and poor prognosis. In addition, HSF1 expression can serve as a biomarker for the prognosis of patients with GC.