Guanylate binding protein 5 accelerates gastric cancer progression via the JAK1-STAT1/GBP5/CXCL8 positive feedback loop.

Guanylate binding protein 5 (GBP5) is a member of the interferon (IFN)-inducible large guanosine triphosphate hydrolases (GTPase) family that regulates cell-autonomous immunity and malignant tumor transformation. However, its specific roles and underlying mechanisms GBP5 in gastric cancer (GC) remain unknown. In this study, we aimed to determine the role GBP5 and underlying mechanism of GBP5 in GC cell progression. Potential oncogenic roles of GBP5 in GC as well as its relationship with the tumor immune microenvironment (TIME) were comprehensively evaluated using bioinformatics analysis. Protein expression levels of GBP5 and their correlation with clinicopathological features of patients were assessed using immunohistochemistry. In addition, diverse in vitro functional experiments were performed to identify the functions of GBP5 in GC. Downstream targets of GBP5 were identified using RNA-sequencing analysis and verified using western blotting or quantitative polymerase chain reaction analysis in different cell lines. GBP5 expression is commonly upregulated and promotes the proliferation and migration of GC cells. Mechanistically, GBP5 was regulated by the IFNγ-Janus kinase (JAK1)-signal transducer and activator of transcription 1 (STAT1) axis and induced CXCL8 expression. Interestingly, GBP5-induced CXCL8 regulated the JAK1-STAT1 signaling pathway to form a positive feedback loop. Moreover, GBP5 is closely related to the TIME and may be used as a biomarker for predicting the efficacy of immunotherapy. Our findings revealed a new JAK1-STAT1/GBP5/CXCL8 pathway and highlighted the value of GBP5 as a predictive biomarker and novel target for GC intervention.

Protective effect of laparoscopic functional total mesorectal excision on urinary and sexual functions in male patients with mid-low rectal cancer.

BACKGROUND: Urinary and sexual dysfunctions are among the most common complications in rectal cancer surgery. This study aimed to investigate the protective effect of laparoscopic functional total mesorectum excision (TME) on urinary and sexual functions in male patients. METHODS: A total of 248 male patients with mid-low rectal cancer were recruited in this study between February 2017 and July 2020. To overcome selection bias, we performed a 1:1 match using six variables, including age, BMI, ASA score, tumor distance, clinical T stage, and tumor size. The urinary function was assessed by the International Prostate Symptom Score (IPSS), sexual function was assessed by a 5-item version of the International Index of Erectile Function (IIEF-5) and ejaculation grading at postoperative 3 and 12 months. RESULTS: 79 patients received functional TME surgery (FTME group), and 169 patients received routine TME surgery (RTME group). After the propensity score, 79 pairs were balanced and analyzed. Patients in the FTME group showed a lower IPSS score and higher IIEF-5 score than patients in the RTME group at postoperative 3 and 12 months. The incidence of ejaculation dysfunction for patients in the FTME group was lower than patients in the RTME group at postoperative 3 and 12 months. CONCLUSION: Laparoscopic functional total mesorectal excision was beneficial to faster recovery of urinary and sexual function for patients with rectal cancer, and it could be used as a superior surgical technique for pelvic autonomic nerve preservation in mid-low rectal cancer.

Significance of Nerve Plane for Inferior Mesenteric Plexus Preservation in Laparoscopic Rectal Cancer Surgery.

Background: Station 253 node dissection with high ligation of the inferior mesenteric artery (IMA) is difficult to perform without damage to the surrounding autonomic nerve plexuses. This study aimed to investigate the significance of the nerve plane for inferior mesenteric plexus (IMP) preservation in laparoscopic rectal cancer surgery. Methods: A total of 56 consecutive rectal patients underwent laparoscopic en bloc station 253 node dissection with high ligation of the IMA. Station 253 nodes were divided into the extra- and intra-nerve plane station 253 nodes for further H&E staining and immunohistochemical analysis. Based on IMP nerve plane-based evidence and histopathological results, a novel nerve-sparing technique, IMP nerve plane orientation, was proposed and performed on 68 rectal cancer patients. Urinary and sexual functions in all patients were evaluated at 6 months postoperatively. Results: Lymph node metastasis was not found, but abundant nerve bundles containing gangliocytes were observed in extra-nerve plane station 253 nodes. The nerve plane was identified intraoperatively and then confirmed by both postoperative gross specimen evaluation and histopathological analysis. The novel nerve-sparing technique (IMP nerve plane orientation) was successfully performed with no postoperative complications, and the operated patients had improved postoperative urinary and sexual functions. Conclusion: The nerve plane is helpful for IMP preservation and station 253 node dissection. This novel nerve-sparing technique of nerve plane orientation is technically feasible and safe, which could result in faster recovery of urinary and sexual functions.

+HOXA10-AS Promotes Malignant Phenotypes of Gastric Cancer via Upregulating HOXA10.

OBJECTIVE: To study the role of long noncoding RNA HOXA10-AS in gastric cancer (GC) and its underlying mechanism which is one of the most common and fetal malignancies. Long noncoding RNA HOXA10-AS is highly expressed and acts in an oncogenic role in cancers. However, its roles in GC are still unknown. METHODS: The expression of HOXA10-AS and HOXA10 in GC tissues from the TCGA database was analyzed. Western blot and qRT-PCR assays were applied to examine the expression of HOXA10-AS and HOXA10. Cell proliferation was evaluated with CCK-8 and EdU incorporation assays. Cell apoptosis was analyzed by flow cytometry. Migratory and invasive capacities were evaluated with wound healing and transwell assays. RESULTS: HOXA10-AS and HOXA10 were upregulated in GC, and their expressions were positively correlated. Knockdown of HOXA10-AS inhibited HOXA10 expression in GC cells. Furthermore, knockdown of HOXA10-AS restrained GC cell proliferation, migration, and invasion but promoted apoptosis. In addition, overexpression of HOXA10-AS promoted malignant phenotypes of GC cells, but all these effects could be reversed by knockdown of HOXA10. CONCLUSION: HOXA10-AS promoted GC cell proliferation, migration and invasion and enhanced apoptosis via upregulating HOXA10. Our study implies a novel regulatory mechanism of malignant phenotypes and provides potential therapeutic targets for GC.

Nerve plane: An optimal surgical plane for laparoscopic rectal cancer surgery?

Radical resection for rectal cancer with total mesorectal excision has been widely recognized in mid-low rectal cancer. Although such surgery reduced the tumor recurrence rate and improved the survival rate of patients, the rate of urinary and sexual dysfunction was high after rectal cancer surgery, which might be attributed to pelvic autonomic nerve injury. The present study found that the pelvic autonomic nerves never exist alone. These are always surrounded by tiny capillaries and adipose tissue and covered by a thin layer of membranous tissue, leading to a continuous plane that should be preserved pelvic autonomic nerve from thermal damage, ischemic injury, nerve stretching, and chemical factors produced by local inflammatory effects. However, the completeness of the continuous plane is easily damaged intraoperatively in routine total mesorectal excision in rectal cancer. Postoperative urinary and sexual dysfunction might be closely associated with the injury of continuous plane. Therefore, the continuous plane should be protected and considered as the optimal surgical plane for rectal cancer surgery.

Risk factors for sexual dysfunction after rectal cancer surgery in 948 consecutive patients: A prospective cohort study.

BACKGROUND: Sexual dysfunctions seriously affect the quality of life of patients. The aim of this study was to identify the risk factors for sexual dysfunction after rectal cancer surgery. METHODS: A total of 948 consecutive patients undergoing rectal cancer radical resection were included between January 2012 and August 2019. The sexual functions were evaluated by the 5-item version of the International Index of Erectile Function (IIEF-5) in men and Index of Female Sexual Function (IFSF) in women at 12 months postoperatively. RESULTS: Postoperative sexual dysfunction was observed in 228 patients with rectal cancer (24.05%), which included 150 cases in male patients (25.0%) and 78 cases in female patients (22.5%). A multivariate logistic regression analysis results showed that age ≥45 years old (OR = 1.72, p = 0.001), tumor below the peritoneal reflection (OR = 1.64, p = 0.005), receiving preoperative radiotherapy (OR = 4.12, p < 0.001) and undergoing abdominoperineal resection (APR), intersphincteric resection (ISR) and Hartmann surgery (OR = 2.43, p < 0.001) were the independent risk factors of sexual dysfunction for patients with rectal cancer. CONCLUSION: Age ≥45 years old, tumors below the peritoneal reflection, receiving preoperative radiotherapy, and undergoing APR, ISR and Hartmann surgery were the independent risk factors of sexual dysfunction. Patients should be informed about the sexual dysfunctions in the pre-operative consultations. More attention should be paid to intraoperative pelvic autonomic nerve preservation on rectal cancer patients with these risk factors for clinic surgeons.

A Nomogram Based on Clinicopathologic Features and Preoperative Hematology Parameters to Predict Occult Peritoneal Metastasis of Gastric Cancer: A Single-Center Retrospective Study.

BACKGROUND: In patients with gastric cancer (GC), peritoneal metastasis is an indication of the end stage and often indicates a poor outcome. The diagnosis of peritoneal metastasis, especially occult peritoneal metastasis (OPM), remains a challenge for surgeons. This study was designed to explore the relationship between OPM and clinicopathological characteristics and preoperative hematological parameters in patients with GC and to develop a nomogram to predict the probability of OPM before surgery. METHODS: A total of 672 patients with GC from our center were included, including 583 OPM-negative and 89 OPM-positive patients. These patients were divided into training and validation groups based on when they received treatment. OPM was diagnosed during surgery in patients without any signs of metastasis through imaging examination. Predictive factors were screened by least absolute shrinkage and selection operator logistic regression of all 18 characteristics. The nomogram of OPM was constructed based on these filtered variables. The discriminative and calibration performance of the model were simultaneously evaluated. RESULTS: A total of six variables, including tumor size, degree of differentiation, depth of invasion, Glasgow prognosis score, and plasma levels of CA125 and fibrinogen, were selected for integration into the final predictive nomogram. The area under curve (AUC) of the nomogram with six factors was 0.906 (95% confidence interval (CI): 0.872-0.941) and 0.889 (95% CI: 0.795-0.984) in the training and validation groups, respectively. Calibration plots of the nomogram in the two sets revealed a good consistency between predicted and actual probabilities. Decision curve analysis showed that the nomogram had a positive net benefit among all threshold probabilities between 0% and 82%. This nomogram was superior to models incorporating only clinicopathologic or hematologic features. CONCLUSION: Both clinicopathological and preoperative hematological parameters are significantly associated with OPM. The nomogram constructed with six factors could be used to calculate the probability of OPM and identify the high-risk population in GC. This may be helpful for early detection of OPM in patients with GC.

miR-635 targets KIFC1 to inhibit the progression of gastric cancer.

Accumulating studies have shown that the dysregulation of microRNAs is related to the carcinogenesis and development of gastric cancer (GC), and the role of miR-635 in GC remains largely unknown. miR-635 and Kinesin Family Member C1 (KIFC1) mRNA expression in GC tissues and paracancerous tissues and cells were detected by quantitative real-time PCR. KIFC1 protein expression in GC tissues and paracancerous normal tissues and cells was detected by immunohistochemistry and western blot. Cell proliferation was monitored by Cell Counting Kit-8 assay and 5-bromo-2'-deoxyuridine assay. Transwell assay was employed to detect the migration and invasion of GC cells. The dual-luciferase reporter gene assay was adopted to detect the targeting relationship between miR-635 and KIFC1. Compared with paracancerous tissues, miR-635 expression was remarkably decreased in GC tissues; conversely, KIFC1 expression was significantly increased. Compared with human normal gastric epithelial cell GSE-1, miR-635 expression was markedly decreased in GC cell lines. Meanwhile, KIFC1 expression was significantly increased, and the Kaplan-Meier Plotter database showed that its high expression was remarkably associated with poor prognosis. Additionally, miR-635 can negatively regulate KIFC1. miR-635 can target KIFC1 to inhibit proliferation, migration and invasion of GC cells. Collectively, miR-635 is lowly expressed in GC, and it inhibits proliferation, migration and invasion of GC cells via regulating KIFC1.

Superoxide Dismutase Mimic, MnTE-2-PyP Enhances Rectal Anastomotic Strength in Rats after Preoperative Chemoradiotherapy.

BACKGROUND: Rectal cancer is one of the malignant diseases with high morbidity and mortality in the world. Currently, surgical resection is the main treatment method, and preoperative chemoradiotherapy (CRT) is widely used in clinical application to increase resectability and decrease the local recurrence rate. However, CRT increases the risk of colon anastomotic leak, and currently, there are no FDA approved treatments against this side effect. It is essential to develop new drugs to reduce postoperative anastomotic leak after preoperative CRT. METHODS: 90 rats underwent standard resection and intestine anastomosis treatment and were divided into six groups for different treatments. During the relaparotomy, bursting pressure of anastomosis was measured and intestinal segments were taken for histopathologic examination and biochemical analyses. RT-PCR and ELISA were applied to measure matrix metalloproteinase (MMP) mRNA and protein levels. Blood vessels were observed by immunohistochemistry, and collagen deposition was observed by Picrosirius Red staining. RESULTS: Preoperative CRT reduced the postoperative anastomotic strength. MnTE-2-PyP increased the bursting pressure and hydroxyproline levels of intestine anastomosis after CRT treatment. Mechanically, MnTE-2-PyP decreased the MMP levels and increased microvessel density (MVD) and collagen deposition. The MMP inhibitor doxycycline had a positive effect on anastomosis healing, but was inferior to MnTE-2-PyP. CONCLUSIONS: MnTE-2-PyP enhanced intestine anastomotic strength in rats with preoperative CRT. Specifically, MnTE-2-PyP decreased MMP levels and increased MVD in anastomosis. Therefore, MnTE-2-PyP may be helpful in the prevention of anastomotic leak after preoperative CRT.

HTRA1 promotes transdifferentiation of normal fibroblasts to cancer-associated fibroblasts through activation of the NF-κB/bFGF signaling pathway in gastric cancer.

Cancer-associated fibroblasts comprise the major stromal cell populations in gastric cancer, which is a significant contributor to cancer-related death worldwide. As a member of the serine protease family, HTRA1 is reportedly involved in malignant transformation of various tumor types. In the present study, we observed that HTRA1 is positively correlated with α-SMA expression in gastric cancer tissues, which was also confirmed by correlation analysis and Gene Set Enrichment Analysis (GSEA) using the GEO database. Upregulation of HTRA1 in gastric cancer cell lines induces expression of α-SMA in normal fibroblasts. To explore how HTRA1 activates normal fibroblasts, an ELISA assay was performed. Secretion of bFGF/FGF2 from gastric cancer cells was significantly increased in response to HTRA1 overexpression. However, upreguation of α-SMA in normal fibroblasts induced by HTRA1 was restored by inhibiting the expression of bFGF. Furthermore, HTRA1 promotes bFGF/FGF2 expression through activation of NF-κB signaling in gastric cancer cells. Inhibition of the NF-κB signaling pathway partially restored baseline expression levels of α-SMA induced by HTRA1. In conclusion, HTRA1 promotes transdifferentiation of normal fibroblasts to cancer-associated fibroblasts by increasing bFGF/FGF2 expression, which is dependent upon activation of NF-κB signaling in gastric cancer.

MnTE-2-PyP Attenuates TGF-ß-Induced Epithelial-Mesenchymal Transition of Colorectal Cancer Cells by Inhibiting the Smad2/3 Signaling Pathway.

BACKGROUND: As a key step in enhancing cancer cell invasion and metastasis, epithelial-mesenchymal transition (EMT) plays an important role in colorectal cancer progression. EMT is triggered by a variety of signaling pathways, among which the transforming growth factor ß (TGF-ß) signaling pathway has been implicated as a primary inducer. Accumulating evidence demonstrates that MnTE-2-PyP (chemical name: manganese(III) meso-tetrakis-(N-ethylpyridinium-2-yl), a superoxide dismutase (SOD) mimetic, inhibits TGF-ß signaling; however, its ability to inhibit TGF-ß-induced EMT in colorectal cancer has not yet been explored. METHODS: To verify our hypothesis that MnTE-2-PyP attenuates TGF-ß-induced EMT, human colorectal cancer cells were treated with TGF-ß in the presence or absence of MnTE-2-PyP. Cells were analyzed by several techniques including western blotting, real-time quantitative PCR, transwell assay, and wound healing assay. RESULTS: MnTE-2-PyP reverses cell phenotypes induced by TGF-ß in colon cancer cells. MnTE-2-PyP treatment significantly reduced the expression of mesenchymal markers but maintained epithelial marker expression. Mechanistically, MnTE-2-PyP suppressed the phosphorylated Smad2/3 protein levels induced by TGF-ß in SW480 cells, but MnTE-2-PyP failed to suppress TGF-ß-induced Slug and Snail expression in colorectal cells. Furthermore, MnTE-2-PyP effectively suppressed TGF-ß-mediated cell migration and invasion and the expression of matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) in colorectal cells. CONCLUSION: Taken together, we provide an in-depth mechanism by which MnTE-2-PyP inhibits colorectal cancer progression, supporting an important role for MnTE-2-PyP as an effective and innovative antitumor agent to enhance treatment outcomes in colorectal cancer.

The Antioxidant Alpha-Lipoic Acid Inhibits Proliferation and Invasion of Human Gastric Cancer Cells via Suppression of STAT3-Mediated MUC4 Gene Expression.

BACKGROUND: Metastasis and invasion are the main causes of mortality in gastric cancer. To improve the treatment of gastric cancer, the development of effective and innovative antitumor agents toward invasion and proliferation is needed. Alpha-lipoic acid (ALA), a naturally occurring thiol antioxidant, showed antiproliferative and cytotoxic effects on several cancers. So it is feasible to explore whether ALA can be used to inhibit proliferation and invasion in human gastric cancer. METHODS: The expression of MUC4 in human gastric cancer tissues was assayed by immunohistochemistry. Then, we performed in vitro cell proliferation and invasion analysis to explore the antitumor effect of ALA using AGS, BGC-823, and MKN-28 cells. To further explore the mechanism of ALA-mediated downregulation of MUC4, we cotransfected human gastric cancer cells with STAT3 siRNA and STAT3 overexpression construct. ChIP assays were carried out to find the relationship between MUC4 and STAT3. RESULTS: We found that the MUC4 gene was strongly expressed in human gastric cancer tissues. Meanwhile, ALA reduced proliferation and invasion of human gastric cancer cells by suppressing MUC4 expression. We also found that STAT3 was involved in the inhibition of MUC4 by ALA. Mechanistically, ALA suppressed MUC4 expression by inhibiting STAT3 binding to the MUC4 promoter region. CONCLUSION: ALA inhibits both proliferation and invasion of gastric cancer cells by suppression of STAT3-mediated MUC4 gene expression.

Genetic variation of long non-coding RNA TINCR contribute to the susceptibility and progression of colorectal cancer.

Colorectal cancer (CRC) accounts for the leading causes of cancer-related morbidity and mortality. However, a large part of heritable factors are warranted to be explored. Long non-coding RNAs (lncRNAs) serve critical roles in cancer development and progression. Herein, we explored effect of genetic variants of Tissue differentiation-inducing non-protein coding RNA (TINCR), a key lncRNA required for somatic tissue differentiation and tumor progression, on risk and progression of CRC. Three tagSNPs, including rs2288947, rs8105637, and rs12610531, were evaluated in in a two-stage, case-control study. Two SNPs, rs2288947 and rs8105637, were significantly associated with susceptibility of CRC in both stages. When pooled together, the allele G was significantly associated with 23% decreased risk of CRC (OR=0.77; 95% CI=0.67-0.88; P value = 1.2×10-4)for SNP rs2288947. While for SNP rs8105637, the allele A was significantly associated with 22% increased risk of CRC (OR=1.22; 95% CI=1.09-1.37; P value = 6.2×10-4). The two SNPs were also statistically associated with occurrence of lymph node metastasis of CRC. The carriers of allele G are less likely to get lymph node metastasis (OR=0.77; 95% CI=0.63-0.94; P value = 0.011) for rs2288947, and the carriers of allele A are more likely to get lymph node metastasis (OR=1.22; 95% CI=1.03-1.43; P value = 0.019) for rs8105637. These results suggest that lncRNA TINCR polymorphisms may be implicated in the development and progression of CRC.

LncRNA GAS5 contributes to lymphatic metastasis in colorectal cancer.

Colorectal cancer (CRC) ranks the third most common type of cancer worldwide. However, the detailed molecular mechanisms underlying these processes are poorly understood. Recent studies have shown that lncRNAs play important roles in carcinogenesis and progression of CRC. The lncRNA growth arrest special 5 (GAS5), was previously identified to be down-regulated and functions as a tumor suppressor gene in many kinds of cancers. In current two-stage, case-control study, we systematically evaluated the potential role of lncRNA GAS5 and its genetic variation rs145204276 in the development and metastasis process of CRC in a Chinese population. We found the allele del of rs145204276 was significantly associated with 21% decreased risk of CRC (OR=0.79; 95% CI=0.70-0.89; P value = 5.21×10-5). Compared with the genotype ins/ins, both the genotype ins/del (OR=0.78; 95% CI=0.68-0.91) and del/del (OR=0.64; 95% CI=0.49-0.84) showed decreased susceptibility. For both in colon and rectum cancers, the associations kept statistically significant (OR=O.78 and 0.80, while P value = 4.56×10-4, and 3.80×10-3, respectively). The results also showed that the carriers of allele del are less likely to get lymph node metastasis (OR=0.80; 95% CI=0.68-0.95; P value = 0.010). Taken together, our findings provided strong evidence for the hypothesis that GAS5 rs145204276 were significantly associated with the susceptibility and progression of CRC.

MicroRNA-103 promotes tumor growth and metastasis in colorectal cancer by directly targeting LATS2.

Colorectal cancer (CRC) has become the third most common cancer worldwide and leads to a high mortality rate. Although colorectal cancer has been studied widely, the underlying molecular mechanism remains unclear. Increasing evidence shows that the abnormal expression of microRNAs (miRNAs) is involved in tumorigenesis. Previous studies have reported that miRNA-103 (miR-103) is dysregulated in CRC; however, the expression, function and mechanism of miR-103 in CRC are not well known. The present study showed that miR-103 was overexpressed in the primary tumor tissues of patients with CRC and was significantly associated with a more aggressive phenotype of CRC in patients. Survival rate analysis demonstrated that CRC patients with high miR-103 expression had a poorer overall survival compared with CRC patients with low miR-103 expression. In CRC cell lines, miR-103 inhibition significantly decreased the proliferation, invasion and migration of the cells in vitro. Furthermore, miR-103 repressed large tumor suppressor kinase 2 (LATS2) expression by directly binding to the LATS2-3'-untranslated region, and an inverse correlation was identified between the expression of miR-103 and LATS2 messenger RNA in primary CRC tissues. In addition, the restoration of LATS2 led to suppressed proliferation, invasion and migration of CRC cells. In vivo, miR-103 promotes tumor growth in nude mice. In summary, miR-103 performs a critical role in the promotion of the invasive and metastatic capacities of CRC, possibly by directly targeting LATS2. This miRNA may be involved in the development and progression of CRC.

Expression of delta-like 4 (Drosophila) and vascular endothelial growth factor A in colon cancer and association with tumour angiogenesis.

OBJECTIVE: Angiogenesis depends on interaction between a variety of promoting and inhibiting factors, and is known to involve vascular endothelial growth factor (VEGF) A and the Notch signaling pathway. The present study investigated the expression of Notch ligand delta-like (DLL) 4 (Drosophila), and VEGFA in colon cancer and colorectal adenoma tissue, and the association with tumour angiogenesis. METHODS: Protein level DLL4, VEGFA and CD34 molecule (CD34) expression was detected immunohistochemically in tissue sections from patients with colon cancer and colorectal adenoma. RESULTS: Out of 80 cases (35 with colon cancer, 45 with colorectal adenoma) DLL4 and VEGFA expression was closely related to tumour diameter, clinical stage, histological grade and lymph node metastasis. DLL4 expression was significantly higher in colon cancer tissue than colorectal adenoma tissue. CONCLUSION: High levels of DLL4 expression were closely related to metastasis and prognosis in patients with colon cancer. The results of the present study support the conclusion that prognosis of colon cancer is significantly correlated with angiogenesis.

Association between STAT3 polymorphisms and cancer risk: a meta-analysis.

Five polymorphisms, rs2293152, rs4796793, rs12949918, rs6503695, rs744166, in the STAT3 gene have been implicated in susceptibility to cancer, but the results were inconclusive. The aim of this meta-analysis is to investigate the association between the five polymorphisms and cancer risk. All eligible case-control studies published up to March 2015 were identified by searching PubMed, Web of Science, Wanfang, VIP, and CNKI. Effect sizes of odds ratio (OR) and 95 % confidence interval (95 % CI) were calculated by using a fixed- or random-effect model. A total of 15 articles were included. Overall, a significantly decreased risk was found for rs12949918 polymorphism (dominant model: OR = 0.83, 95 % CI: 0.75-0.91, recessive model: OR = 0.77, 95 % CI: 0.68-0.87, TC vs. TT: OR = 0.87, 95 % CI: 0.79-0.96, CC vs. TT: OR = 0.71, 95 % CI: 0.62-0.81), and for rs744166 polymorphism (recessive model: OR = 0.75, 95 % CI: 0.58-0.98; GG vs. AA: OR = 0.68, 95 % CI: 0.51-0.90), while there was no significant association for other three polymorphisms under all genetic models. In subgroup analysis by ethnicity, for rs12949918 polymorphism, similar results were detected among Caucasians, similarly, a significant decreased risk was observed in Asians under dominant and CC vs. TT model; for rs2293152 polymorphism, significant association was detected among Asians under recessive model. This meta-analysis suggests that the STAT3 rs12949918 and rs744166 polymorphisms, but not other three polymorphisms, may be an important protective factor for cancer.

Paeoniflorin inhibits human gastric carcinoma cell proliferation through up-regulation of microRNA-124 and suppression of PI3K/Akt and STAT3 signaling.

AIM: To examine the potential anti-tumor activity of paeoniflorin in the human gastric carcinoma cell line MGC-803. METHODS: Cell viability and cytotoxic effects in MGC-803 cells were analyzed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assay, respectively. Cell apoptosis of MGC-803 cells was measured using flow cytometry, DAPI staining assay and caspase-3 activity assay. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the expression of microRNA-124 (miR-124) in response to paeoniflorin. The expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), phospho-Akt (p-Akt) and phospho-signal transducer and activator of transcription 3 (p-STAT3) were also measured by quantitative RT-PCR and Western blot analysis in normal, miR-124 and anti-miR-124 over-expressing MGC-803 cells, treated with paeoniflorin. RESULTS: Paeoniflorin was found to inhibit MGC-803 cell viability in a dose-dependent manner. Paeoniflorin treatment was associated with the induction of apoptosis and caspase-3 activity in MGC-803 cells. Paeoniflorin treatment significantly increased miR-124 levels and inhibited the expression of PI3K, Akt, p-Akt and p-STAT3 in MGC-803 cells. Interestingly, the over-expression of miR-124 inhibits PI3K/Akt and phospho-STAT3 expressions in MGC-803 cells. PI3K agonist (IGF-1, 1 µg/10 µL) or over-expression of STAT3 reversed the effect of paeoniflorin on the proliferation of MGC-803 cells. Over-expression of anti-miR-124 in MGC-803 cells reversed paeoniflorin-induced up-regulation. CONCLUSION: In summary, the in vitro data suggest that paeoniflorin is a potential novel therapeutic agent against gastric carcinoma, which inhibits cell viability and induces apoptosis through the up-regulation of miR-124 and suppression of PI3K/Akt and STAT3 signaling.

Nucleostemin regulates proliferation and migration of gastric cancer and correlates with its malignancy.

OBJECTIVE: The aim of this study was to investigate the effects of nucleostemin (NS) knocking down in SGC- 7901 gastric cancer cell line and investigates its correlation with the metastasis and TNM stage ingastric cancer (GC) patients. METHODS: NS expression was assessed using immunohistochemistry in 421 patients with GC. The correlation between NS expression, clinicopathological features and prognosis was analyzed. NS gene silencing was performed using a specific small interfering RNA (NS-siRNA). The gene expression level of NS was evaluated by PCR. The viability and growth rate of SGC-7901 cells were determined by trypan blue exclusion test. Cell cycle distribution of the cells was analyzed by flow cytometry. RESULTS: High NS expression was correlated with node metastasis, distant metastasis and TNM stage. Kaplan-Meier survival analysis revealed that patients with low NS expression had significantly longer survival than those with high NS expression. Moreover, our results showed that NS knocking down inhibited proliferation and viability of SGC-7901 cells in a time-dependent manner. Cell cycle studies revealed that NS depletion resulted in G1 cell cycle arrest at short times of transfection (24 h) followed with apoptosis at longer times (48 and 72 h), suggest that post-G1 arrest apoptosis is occurred in SGC-7901 cells. CONCLUSION: Overall, these results point to essential role of NS in SGC-7901 cells, thus, this gene might be considered as a promising target for treatment of GC.

HTRA1 gene expression in gastric epithelial cells.

OBJECTIVES: To explore HtrA1 gene expression and its regulation in human gastric cancers. METHODS: The HtrA1 mRNA levels were examined by QPCR analysis and confirmed its expression with Northern blot analysis. The HtrA1 protein levels in all six gastric epithelial cell lines were investigated by Western blot analysis. Gene copy number was accessed and then sequenced the coding region from each mRNA in all six cell lines. The HtrA1 promoter region DNA methylation status was detected by using bisulfite sequencing analysis. Effect of decitabine and TSA on HTRA1 expression in gastric cancer cell line was determined by RTPCR. RESULTS: HIC analysis indicated that HtrA1 was highly expressed in normal epithelium, but dramatically down-regulated in gastric carcinoma tissues and variably expressed in tumor-adjacent tissues. HtrA1 gene expression was dramatically decreased in gastric carcinoma cells compared to non-tumorigenic counterparts. The HtrA1 gene loss in any of the 4 breast cancer cell lines was not detected. Total 14 CpGs in this region were all methylated in gastric cancer cells, whereas two normal cells, GES-1 and HFI-145, were having several unmethylated cytosines in this region. HtrA1 showed as ~Mr 44,000, Expression of HtrA1 protein was not observed in any of the four gastric cancer cell lines, BGC-823, MKN-45, SGC-7901and MKN-28. HtrA1 expression was observed in the HFI-145and GES-1 cell lines. CONCLUSIONS: The epigenetic silencing for HtrA1 gene expression could provide a possible strategy for re-activating HtrA1 gene expression in gastric cancer cells, thus facilitating further investigation of HtrA1's role in chemotherapy.