ALKBH5-mediated CHAC1 depletion promotes malignant progression and decreases cisplatin-induced oxidative stress in gastric cancer.

The m6a demethyltransferase ALKBH5 dynamically modulates gene expression and intracellular metabolic molecules by modifying RNA m6a in cancer cells. However, ALKBH5's function in gastric cancer (GC) has remained controversial. This study demonstrates that ALKBH5 is highly expressed in GC. Silencing ALKBH5 hampers proliferation, and metastatic potential, and induces cell death in GC cells. Through a comprehensive analysis of the transcriptome and m6A sequencing, alterations in certain ALKBH5 target genes, including CHAC1, were identified. ALKBH5's demethylation effect regulates CHAC1 RNA stability, leading to reduced CHAC1 expression. Moreover, CHAC1 modulates intracellular ROS levels, influencing the chemotherapy sensitivity of gastric cancer. In summary, our study unveils the pivotal role of the ALKBH5-CHAC1-ROS axis and highlights the significance of m6A methylation in gastric cancer.

Single-cell RNA-seq dissecting heterogeneity of tumor cells and comprehensive dynamics in tumor microenvironment during lymph nodes metastasis in gastric cancer.

Lymph node metastasis is the common metastasis route of gastric cancer. However, until now, heterogeneities of tumor cells and tumor microenvironment in primary tumors (PT) and metastatic lymph nodes (MLN) of gastric cancer (GC) remains uncharacterized. In our study, single cell RNA sequencing was performed on tissues from PT and MLN of gastric cancer. Trajectory analysis and function enrichment analyses were conducted to decode the underlying mechanisms contributing to LN metastasis of gastric cancer. Heterogeneous composition of immune cells and distinct intercellular interactions in PT and MLN were analyzed. Based on the generated single cell transcriptome profiles, dynamics of gene expressions in cancer cells between PT and MLN were characterized. Moreover, we reconstructed the developmental trajectory of GC cells' metastasis to LN and identified two subtypes of GC cells with distinct potentials of having malignant biological behaviors. We characterized the repression of neutrophil polarization associated genes, like LCN2, which would contribute to LN metastasis, and histochemistry experiments validated our findings. Additionally, heterogeneity in neutrophils, rather than macrophages, was characterized. Immune checkpoint associated interaction of SPP1 was found active in MLN. In conclusion, we decode the dynamics of tumor cells during LN metastasis in GC and to identify a subtype of GC cells with potentials of LN metastasis. Our data indicated that the disordering the neutrophils polarization and maturation and the activation of immune checkpoint SPP1 might contribute to LN metastasis in GC, providing a novel insight on the mechanism and potential therapeutic targets of LN metastasis in GC.

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.

XRCC1 R399Q polymorphism and colorectal cancer risk in the Chinese Han population: a meta-analysis.

X-ray repair cross-complementing group 1 (XRCC1) plays a key role in DNA repair, genetic instability, and tumorigenesis. The XRCC1 R399Q polymorphism has been reported in some studies to influence the risk of colorectal cancer (CRC), though this remains controversial. We performed a meta-analysis to determine the association of XRCC1 R399Q polymorphisms with CRC risk in the Chinese Han population. A literature search was conducted using PubMed, EMBASE, and the China National Knowledge Infrastructure to identify eligible studies published before June 2014. The pooled odds ratio (OR) and corresponding 95% confidence interval (CI) were used to estimate the effect of XRCC1 R399Q polymorphisms on CRC risk. Eleven case-control studies with a total of 3194 CRC cases and 4472 controls were identified. No significant association between the XRCC1 R399Q polymorphism and CRC risk was observed in the Chinese Han population (Gln/Gln vs. Arg/Arg, OR = 1.26, 95% CI = 0.85-1.87, P OR = 0.242; Arg/Gln vs. Arg/Arg, OR = 0.95, 95% CI = 0.70-1.18, P OR = 0.651; dominant model, OR = 1.09, 95% CI = 0.86-1.38, P OR = 0.480; and recessive model, OR = 1.24, 95% CI = 0.91-1.70, P OR = 0.177). After excluding two studies that deviated from the Hardy-Weinberg equilibrium, there remained no significant association between XRCC1 R399Q and CRC risk. No publication bias was found using the funnel plot and Egger's test. Our meta-analysis results suggest that the XRCC1 R399Q polymorphism is not associated with increased risk of CRC in the Chinese Han population.

Expression of ZNF281 in colorectal cancer correlates with response to radiotherapy and survival.

BACKGROUND: The treatment of Colorectal cancer (CRC) is extremely complex and survival rates vary depending on the stage of the disease at the time of diagnosis. Neoadjuvant chemoradiotherapy (NACRT), is the conventional treatment for locally advanced rectal cancer (LARC); however, the resistance to chemoradiotherapy in LARC is difficult to predict. MATERIALS AND METHODS: In this study, clinical data of 126 LARC patients were collected and analyzed, and relevant validation was performed using GEO database and in vitro and in vivo experiments, including Western blotting and Real-time quantitative PCR, immunohistochemistry, immunofluorescence, clonogenic cell survival assays, and nude-mouse xenograft models. RESULTS: In patients with LARC who were treated with neoadjuvant radiotherapy (NART), higher ZNF281 expression in malignant tissue was associated with a poorer prognosis and lesser degree of tumor regression. Cell and mouse experiments have shown that ZNF281 reduces the damage caused by X-rays to CRC cells and tumors grown in mice. CONCLUSION: We found that the expression of ZNF281 predicted the radiation response of CRC cells and suggested the prognosis of patients with LARC who received neoadjuvant radiation therapy.

Spindle function and Wnt pathway inhibition by PBX1 to suppress tumor progression via downregulating DCDC2 in colorectal cancer.

PBX1 is a transcription factor that regulates a variety of genes, involved in intracellular lipid metabolism, cell proliferation, and other pathways. The promoting and inhibiting function of PBX1 in various cancer types was extensively discussed, however, there have been no studies on PBX1 proteins in colorectal cancer (CRC). This study aimed to reveal the anti-tumor function of PBX1 in CRC and the underlying molecular mechanism. Bioinformatics analysis revealed that PBX1 is downregulated in CRC, indicating that is a potential antioncogene in CRC. Overexpression of PBX1 suppresses tumor growth and metastasis in vitro and in vivo. Mechanistically, we found that PBX1 acted as a transcription factor that suppressed DCDC2 expression and inhibited spindle function. Moreover, the PBX1-DCDC2 axis controlled the Wnt pathway in CRC cells. Overexpression of DCDC2 restored CRC proliferation, metastasis abilities and Wnt pathway. In conclusion, this study suggests that PBX1 acts as a transcription factor to suppress DCDC2 expression and inhibit cell proliferation and metastasis by disrupting spindle function and the Wnt pathway in CRC.

Genotyping guided ripretinib directly after the progression of first-line imatinib therapy in advanced gastrointestinal stromal tumor: a case report.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Surgery and tyrosine kinase inhibitor (TKI) therapy are the main choices of treatment. However, the long-term use of TKIs is prone to drug resistance. Herein, we report the case of a 47-year-old female with primary gastric GIST with liver metastases since June 2015. The patient achieved disease control under imatinib therapy and underwent primary lesion resection. She took postoperative imatinib maintenance therapy, but discontinued imatinib for 10 months about 2 years after surgery. The patient suffered from disease progression in May 2019, with recurrence of liver metastases and new abdominal metastases. From then on, imatinib was resumed and partial response (PR) persisted for another 2 years. The patient subsequently experienced tumor progression due to secondary KIT exon 17 mutation confirmed by tissue biopsy and circulating tumor DNA (ctDNA) detection. After multidisciplinary team discussion, the patient received ripretinib as a second-line therapy, and ctDNA monitoring demonstrated that the KIT mutations turned negative. After disease control from ripretinib for 2+ months, she underwent cytoreductive surgery (R0/1) and received ripretinib maintenance treatment postoperatively. We believe that this case provides a reference value for individualized ripretinib precise therapy according to mutational analysis after the progression of first-line GIST treatment, and ctDNA can predict effectiveness to guide treatment.

m6 A-mediated regulation of PBX1-GCH1 axis promotes gastric cancer proliferation and metastasis by elevating tetrahydrobiopterin levels.

BACKGROUND: Methyltransferase 3 (METTL3)-mediated N6-methyladenosine (m6 A) RNA modification has been demonstrated to be a potential factor in promoting gastric cancer (GC). METTL3 regulates a series of signaling pathways by modifying various mRNAs. This study aimed to identify novel METTL3-mediated signaling pathways and explored possible targets for use in the clinical setting of gastric cancer. METHODS: To investigate the proliferation and metastatic capacity of GC cell lines with METTL3 knockdown, a xenograft, lung metastasis, and popliteal lymph node metastasis model was used. The m6 A-modified RNA immunoprecipitation (Me-RIP) sequence was utilized to explore the target mRNAs of METTL3. Cell counting kit 8 and transwell assays were performed to investigate the promoting function of pre-B cell leukemia homeobox 1 (PBX1) and GTP cyclohydrolase 1 (GCH1). Western blotting and chromatin immunoprecipitation were employed to confirm the involvement of the METTL3-PBX1-GCH1 axis. ELISA and liquid chromatography-mass spectrometry were used to explore the biological function of tetrahydrobiopterin (BH4 ). RESULTS: Knockdown of METTL3 suppressed xenograft tumor growth and lung/lymph node metastasis in vivo. Mechanistically, we found that METTL3 combined with and stabilized PBX1 mRNAs. Chromatin immunoprecipitation (ChIP) and further experiments suggested that PBX1 acted as a transcription factor inducing GCH1 expression. Moreover, the METTL3-PBX1-GCH1 axis increased BH4 levels in GC cells, thereby promoting tumor progression. CONCLUSIONS: This study suggested that METTL3 enzymes promote tumor growth and lung/lymph node metastasis via METTL3-PBX1-GCH1 axis increasing BH4 levels in GC.

PARP inhibitor olaparib enhances the efficacy of radiotherapy on XRCC2-deficient colorectal cancer cells.

The use of PARP inhibitors in combination with radiotherapy is a promising strategy to locally enhance DNA damage in tumors. Loss of XRCC2 compromises DNA damage repairs, and induced DNA damage burdens may increase the reliance on PARP-dependent DNA repairs of cancer cells to render cell susceptibility to PARP inhibitor therapy. Here we tested the hypothesis that XRCC2 loss sensitizes colorectal cancer (CRC) to PARP inhibitor in combination with radiotherapy (RT). We show that high levels of XRCC2 or PARP1 in LARC patients were significantly associated with poor overall survival (OS). Co-expression analyses found that low levels of PARP1 and XRCC2 were associated with better OS. Our in vitro experiments indicated that olaparib+IR led to reduced clonogenic survival, more DNA damage, and longer durations of cell cycle arrest and senescence in XRCC2-deficient cells relative to wild-type cells. Furthermore, our mouse xenograft experiments indicated that RT + olaparib had greater anti-tumor effects and led to long-term remission in mice with XRCC2-deficient tumors. These findings suggest that XRCC2-deficient CRC acquires high sensitivity to PARP inhibition after IR treatment and supports the clinical development for the use of olaparib as a radiosensitizer for treatment of XRCC2-deficient CRC.

A SERPINE1-Based Immune Gene Signature Predicts Prognosis and Immunotherapy Response in Gastric Cancer.

Immune checkpoint inhibitors (ICIs) therapy has been successfully utilized in the treatment of multiple tumors, but only a fraction of patients with gastric cancer (GC) could greatly benefit from it. A recent study has shown that the tumor microenvironment (TME) can greatly affect the effect of immunotherapy in GC. In this study, we established a novel immune risk signature (IRS) for prognosis and predicting response to ICIs in GC based on the TCGA-STAD dataset. Characterization of the TME was explored and further validated to reveal the underlying survival mechanisms and the potential therapeutic targets of GC. The GC patients were stratified into high- and low-risk groups based on the IRS. Patients in the high-risk group, associated with poorer outcomes, were characterized by significantly higher immune function. Further analysis showed higher T cell immune dysfunction and probability of potential immune escape. In vivo, we detected the expressions of SERPINE1 by the quantitative real-time polymerase chain reaction (qPCR)in tumor tissues and adjacent normal tissues. In vitro, knockdown of SERPINE1 significantly attenuated malignant biological behaviors of tumor cells in GC. Our signature can effectively predict the prognosis and response to immunotherapy in patients with GC.

Extensive Dissection at No. 12 Station During D2 Lymphadenectomy Improves Survival for Advanced Lower-Third Gastric Cancer: A Retrospective Study From a Single Center in Southern China.

BACKGROUND: D2 lymphadenectomy including No. 12a dissection has been accepted as a standard surgical management of advanced lower-third gastric cancer (GC). The necessity of extensive No. 12 nodes (No. 12a, 12b, and 12p) dissection remains controversial. This study aims to explore its impact on long-term survival for resectable GC. METHODS: From 2009 to 2016, 353 advanced lower-third GC patients undergoing at least D2 lymphadenectomy during a radical surgery were included, with 179 patients receiving No. 12a, 12b, and 12p dissection as study group. A total of 174 patients with No. 12a dissection were employed as control group. Surgical and long-term outcomes including 90-day complications incidence, therapeutic value index (TVI), 3-year progression-free survival (PFS), and 5-year overall survival (OS) were compared between both groups. RESULTS: No. 12 lymph node metastasis was observed in 20 (5.7%) patients, with 10 cases in each group (5.6% vs. 5.7%, p = 0.948). The metastatic rates at No. 12a, 12b, and 12p were 5.7%, 2.2%, and 1.7%, respectively. The incidence of 90-day complications was identical between both groups. Extensive No. 12 dissection was associated with increased TVI at No. 12 station (3.9 vs. 0.6), prolonged 3-year PFS rate (67.0% vs. 55.9%, p = 0.045) and 5-year OS rate (66.2% vs. 54.0%, p = 0.027). The further Cox-regression analysis showed that the 12abp dissection was an independent prognostic factor of improved survival (p = 0.026). CONCLUSION: Adding No. 12b and 12p lymph nodes to D2 lymphadenectomy might be effective in surgical treatment of advanced lower-third GC and improve oncological outcomes compared with No. 12a-based D2 lymphadenectomy.

Comprehensive Analysis and Identification of Prognostic Biomarkers and Therapeutic Targets Among FAM83 Family Members for Gastric Cancer.

Background: Gastric cancer (GC) is one of the most common and poor prognosis malignancy in the world. The Family with sequence similarity 83 (FAM83) comprises of eight members of A-H. Accumulating evidence confirmed important roles for FAM83 family in tumorigenesis and progression. However, the prognostic values of FAM83 family in GC still have not been clarified. Methods: ONCOMINE, UALCAN, GEPIA, THE HUMAN PROTEIN ATLAS, Kaplan-Meier Plotter, cBioPortal, DAVID, STRING and TIMER databases and R software were adopted in this study. Results: In this study, we demonstrated that the mRNA levels of FAM83 B/C/D/H were significantly up-regulated in stomach adenocarcinoma (STAD), but the protein level of FAM83G/H were remarkable lowly in STAD. Next, FAM83C/D/G/H were significantly associated with tumor stages in STAD patients. Then, the mutation rate of FAM83 family members in STAD patients was 46%, and the highest mutation rate was FAM83H (23%). Furthermore, the functions of FAM83 family and their 259 co-expression genes were primarily related to Shigellosis, RNA degradation and Ribosome biogenesis in eukaryotes pathway. Besides, we have established the prognostic model of FAM83 family in STAD, including the prognostic model of STAD patients (FAM83C/D/G), STAD with lymph node metastasis (FAM83C/D/G/H) and STAD with ERBB2 high expression (FAM83G/H). FAM83C/D high expression with a poor prognosis, while FAM83G/H high expression with a favorable prognosis of STAD. Additionally, we found that the expression of FAM83C/D/G/H were significantly correlated with the infiltration of six types of immune cells [B cells, CD8+T cells, CD4+T cells, macrophages and Myeloid dendritic cells (DC)], whereas CD4+T cells and Macrophage cells have higher risk scores (HR > 1) when FAM83C lowly expression and FAM83D highly expression. The risk score of NK cells was significantly reduced when FAM83G lowly expression and FAM83H highly expression (HR < 1). Conclusion: These findings suggested that FAM83C/D/G/H might play key roles in STAD tumorigenesis and progression, and FAM83C/D might be risk factors but FAM83G/H might be favorable prognostic factors for STAD patients. In addition, CD4+T cells and Macrophage cells may be the promoters of FAM83D in progression of STAD, while NK cells may promote the protective effect of FAM83H on STAD patients.

A Substage Increase in The AJCC Classification System Improves Prognostic Prediction in Stage III Gastric Cancer With Insufficient Lymph Nodes Removed.

BACKGROUND: The impact of lymph nodes (LNs) removed on the survivals of patients with stage III gastric cancer, especially on that of those who undergo the adjuvant chemotherapy as a compensation for a possibly insufficient lymphadenectomy, is still unclear. METHODS: Consecutive patients (n = 488) with stage III gastric cancer under R0 curative resection followed by adjuvant chemotherapy were analyzed. The overall survival (OS) was compared between patients with insufficient LNs removed (ILNr, <16 LNs) and sufficient LNs removed (SLNr, ≥16 LNs). Performance of the prediction systems was evaluated using the Likelihood ratio χ2 test, Akaike information criterion (AIC), Harrell's concordance index (C-index), and area under the receiver operating characteristic curves (AUC). RESULTS: The OS of patients were significantly longer in those with SLNr relative to those with ILNr (for stage IIIA, 68.2 vs. 43.2 months, P = 0.042; for stage IIIB, 43.7 vs. 24.9 months, P < 0.001; for stage IIIC, 23.9 vs. 8.3 months, P < 0.001; and for total stage III, 37.7 vs. 21.7 months, P < 0.001). However, the OS were similar between stage IIIA patients with ILNr and stage IIIB patients with SLNr (P = 0.928), between IIIB patients with ILNr and IIIC patients with SLNr (P = 0.962), and IIIC patients with ILNr and stage IV (P = 0.668), respectively. A substage increase in the AJCC classification system, from IIIA to IIIB, from IIIB to IIIC, and from IIIC to IV in patients with ILNr, enhanced the accuracy of prognostic prediction in patients with stage III gastric cancer compared to the current TNM system (Likelihood ratio χ2, 188.6 vs. 184.8; AIC, 4336.4 vs. 4340.6; C-index, 0.695 vs. 0.679, P = 0.002). The ROC curves revealed that the performance of prognostic prediction was better in the new prediction system (AUC = 0.699) compared with the current TNM system (AUC = 0.676). CONCLUSIONS: ILNr (LNs <16) impairs the long-term outcomes of stage III gastric cancer underwent adjuvant chemotherapy. The status of LNs removal adds values to the current TNM system in prognostic prediction of stage III gastric cancer.

FGF14 Functions as a Tumor Suppressor through Inhibiting PI3K/AKT/mTOR Pathway in Colorectal Cancer.

We identified that Fibroblast Growth Factor 14 (FGF14) was preferentially methylated in colorectal cancer (CRC). In this study, we aimed to investigate the epigenetic regulation, biological function and molecular mechanism of FGF14 in CRC. The expression of FGF14 in CRC cell lines, normal human colon epithelial cell line, CRC tissues and paired adjacent normal tissues was detected by PCR and Western blot. The biological function of FGF14 in CRC was interrogated by cell viability assay, colony formation, flow cytometry, cell invasion and migration assay, as well as in vivo study. We found FGF14 was downregulated or silenced in all (10/10) CRC cell lines, while it was expressed in normal colonic tissues and normal human colon epithelial cell line. The expression of FGF14 was lower in primary CRCs as compared to their adjacent normal tissues. Significant higher methylation of FGF14 was observed in CRCs than that in normal tissues based on the data from TCGA database. The loss of FGF14 gene expression was restored by treatment with DNA methyltransferase inhibitor 5-Aza. Re-expression of FGF14 in CRC cell lines inhibited cell viability and colony formation, and induced cell apoptosis. FGF14 induced mitochondrial apoptosis and inhibited PI3K/AKT/mTOR pathway. In xenograft mouse model, overexpression of FGF14 significantly reduced tumor growth (P<0.001). In conclusion, FGF14 is a novel tumor suppressor, which suppresses cell proliferation and induces cell apoptosis via mediating PI3K/AKT/mTOR pathway.

Apolipoprotein C1 (APOC1) promotes tumor progression via MAPK signaling pathways in colorectal cancer.

Aim: Identifying high-efficiency prognostic markers for colorectal cancer (CRC) is necessary for clinical practice. Increasing evidence demonstrates that apolipoprotein C1 (APOC1) promotes carcinogenesis in some human cancers. However, the expression status and biological function of APOC1 in CRC remain unclear. Materials and methods: We detected the association between APOC1 expression and clinicopathological features in 140 CRC patients by immunohistochemistry. Small interfering RNA (siRNA) technology was used to downregulate APOC1 expression in CRC cells. Cell proliferation was estimated by CCK8 and clonogenic assays. The cell cycle and apoptosis were analyzed by flow cytometry. Cell migration and invasion were examined by a transwell assay. Gene set enrichment analysis (GSEA) and protein expression of signaling pathways were used to suggest the possible APOC1-associated pathways in CRC. Results: APOC1 was highly expressed in CRC tissues. High immunohistochemistry (IHC) expression of APOC1 was correlated with the N stage, M stage and TNM stage. High IHC APOC1 expression in CRC tissues was associated with poor prognosis. Univariate and multivariate Cox regression analyses showed that APOC1 was an independent risk factor for OS. Cell proliferation of CRC cell lines was inhibited by the downregulation of APOC1. Moreover, si-APOC1 transfection induced cell cycle arrest but low apoptosis increases by regulating the expression of related proteins. Cell migration and invasion were also inhibited by the downregulation of APOC1. The Cancer Genome Atlas Colorectal Adenocarcinoma (TCGA COAD-READ) dataset analyzed by GSEA showed that APOC1 might be involved in the mitogen-activated protein kinase (MAPK) signaling pathway, which was further preliminarily confirmed by Western blotting. Conclusion: APOC1 was overexpressed in CRC tissues, and a high level of APOC1 contributed to a poor prognosis. APOC1 expression influenced the cell proliferation ability and motility capacity of CRC via the MAPK pathway. APOC1 could act as a novel prognostic biomarker in 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.

Sorting nexin-1 is a candidate tumor suppressor and potential prognostic marker in gastric cancer.

Sorting nexin-1 (SNX1) is an important functional protein in cell endocytosis, efflux, protein sorting, cell signal transduction, etc; however, the expression, the role and clinical relevance of SNX1 have not been investigated in gastric cancer (GC). In this study, we first performed a bioinformatics investigation using the data obtained from The Cancer Genome Atlas (TCGA) database. The result showed that SNX1 mRNA levels were significantly lower in GC tissues than in paracancerous tissues. In a study of 150 cases of GC, including 60 cases with paired paracancerous and cancer tissues and 90 cases with detailed follow-up information, SNX1 expression was analyzed by immunohistochemistry. Our study on paired paracancerous and cancer tissues showed that SNX1 protein expression remarkably decreased in GC tissues (50/60, 83.33%). A study on 90 patients with detailed follow-up information showed that tumors with higher SNX1 protein level were correlated with better clinicopathologic stages (p = 0.0285), nodal status (p = 0.0286), smaller tumor sizes (p = 0.0294) and a better survival rate in patients with GC (p = 0.0245). Univariate analysis of the 90 patients with GC showed that low-level SNX1 was significantly correlated with decreased overall survival of GC patients (p = 0.008), and associated with a relatively higher cumulative hazard of death. Exogenous expression of SNX1 inhibited the growth, migration, invasion and promoted the apoptosis and enhanced the sensitivity of GC cells to the chemotherapeutic drug 5-Fluorouracil (5-Fu) in vitro, while knockdown of SNX1 by short hairpin RNA (shRNA) significantly promoted the growth, migration, invasion and reduced the apoptosis and the sensitivity of GC cells to 5-Fu. SNX1 also showed to influence the levels of epithelial-mesenchymal transition markers including Vimentin, Snail, and E-cadherin in GC cells in vitro. Taken together, we propose here that SNX1 serves as a tumor suppressor and prognostic marker that reduces tumor cell malignancy for 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.

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

BACKGROUND: Heat 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). METHODS: The 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. RESULTS: The 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. CONCLUSIONS: Taken 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.

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

BACKGROUND: Stress-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). METHODS: In 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. RESULTS: In 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/ß-catenin signaling pathway, including c-Myc and Cyclin D1, and accompanied with nuclear translocation of ß-catenin. CONCLUSIONS: Our findings indicate that elevated expression of STIP1 exhibited a metastasis-promoting effect in GC cells through activation of Wnt/ß-catenin signaling pathway. STIP1 may be served as a potential therapeutic target for preventing GC metastasis.