Glucose 6 phosphatase dehydrogenase (G6PD): a novel diagnosis marker related to gastrointestinal cancers.

BACKGROUND: Glucose 6 phosphatase dehydrogenase (G6PD) is a key regulator of the pentose phosphate pathway (PPP). However, the exact role of G6PD in gastrointestinal cancers remains unclear. The purpose of this study is to explore the correlation of G6PD with clinical features, pathological stages, diagnosis and prognosis of gastrointestinal cancers, as well as uncover possible mechanisms of G6PD on mutations, immunity and signaling pathways. METHODS: G6PD mRNA expression data were downloaded from TCGA and GEO databases. Protein expression was examined by the HPA database. The correlation of G6PD expression with clinical and pathological characteristics was explored. The pROC package in R language was used to evaluate the diagnostic value of G6PD expression in gastrointestinal cancers. We accessed the correlation of disease-free survival (DFS) with G6PD online by Kaplan-Meier plotter. Univariate Cox regression and stepwise multiple Cox regression analysis were performed to determine the association between G6PD and patient's overall survival. In addition, genomic alterations, mutation profiles, immune infiltration, drug sensitivity and enrichment analysis related with G6PD were visualized. RESULTS: After a pan-cancerous genomic analysis, we found that G6PD expression was the highest in African American esophageal carcinoma (ESCA) patients (P<0.05). G6PD was correlated with age, weight, disease stage, lymph node metastasis and pathological grade. Notably, G6PD showed an excellent predictive diagnosis ability for liver hepatocellular carcinoma (LIHC) (AUC=0.949, 95% CI=0.925-0.973, P<0.001). G6PD can improve the DFS of esophageal adenocarcinoma (EAC) and pancreatic adenocarcinoma (PAAD) patients (P<0.05). Both Univariate Cox regression and stepwise multiple Cox regression analysis in R language determined that G6PD expression was closely related with LIHC (P<0.001). G6PD was found to have a high mutation rate in colon adenocarcinoma and ESCA and gene amplification in ESCA, Cholangiocarcinoma, PAAD and LIHC. Copy number of G6PD was missing in LIHC. G6PD was also related to mutation of TP53 (P<0.05). Particularly, it was positively correlated with CD276 in all gastrointestinal cancers and negatively with HERV-H LTR-associating 2 in ESCA and stomach adenocarcinoma. The abnormal expression of G6PD was related to the increase of CD4+ Th2 subsets and the decrease of CD4+ (non-regulatory) of T cells. G6PD was sensitive to FK866, Phenformin, AICAR etc., while resistant to RO-3306, CGP-082996, TGX221 etc. G6PD was found to closely interact with TALDO1, GAPDH and TP53. G6PD related biological processes included aging, nutritional response and daunorubicin metabolism, and related pathways included PPP, cytochrome P450 metabolism of exogenous substances and glutathione metabolism. CONCLUSION: G6PD is highly expressed in gastrointestinal cancers. It is a carcinogenic indicator related to prognosis and can be used as a potential diagnostic marker of gastrointestinal cancers, so as to provide new strategy for cancer treatment.

[Effects of oxymatrine and vincristine on drug resistance in HCT-8/VCR cells and its mechanism].

OBJECTIVE: To study the effects of oxymatrine and vincristine on resistance in HCT-8/VCR cells and its mechanism. METHODS: HCT-8 / VCR cells were cultured in vitro and were divided into blank control group, oxymatrine group, vincristine group, oxymatrine and vincristine combined group, each group had 6 complexes. The drug resistance of HCT-8/VCR cells was investigated by CCK-8 when treated with vincristine alone or in combination with oxymatrine. The autophagy was determined by monodansylcadaverine (MDC) staining. The level of IL-6 was detected by ELISA. The expressions of autophagy-related gene P62, LC3-Ⅱ / LC3-Ⅰ, Beclin-1 protein and TLR4 were detected by Western blot assay. RESULTS: Oxymatrine combined with vincristine could reduce the drug resistance of HCT-8 / VCR cells by the reversal multiple of 3.23. Compared with the blank control group, the content of autophagosome and the content of IL-6 in the oxymatrine group and the combination group were also decreased significantly (P＜0.01). The content of autophagosome in the vincristine group was increased and the content of IL-6 was also significantly increased (P＜0.01). Compared with the oxymatrine group, the combination group had higher autophagosome content, while IL-6 content was decreased (P＜0.01); Western blot experiments showed that compared with the blank control group, the expression of P62 in the oxymatrine group was decreased (P＜0.05), while the expressions of LC3-Ⅱ / LC3-Ⅰ, Beclin-1 and TLR4 were all increased (P＜0.05). The expression of P62 in the vincristine group and the combined group was increased (P＜0.05), and the expressions of LC3-Ⅱ / LC3-Ⅰ, Beclin-1, and TLR4 were all decreased (P＜0.05). Compared with the vincristine group, the expression of P62 was increased in the combination group (P＜0.05), and the expressions of LC3-Ⅱ / LC3-Ⅰ, Beclin-1, and TLR4 were all decreased (P＜0.05). CONCLUSION: Oxymatrine combined with vincristine can reduce the drug resistance of HCT-8/VCR cells, which may be related to the regulation of autophagy activity and TLR4 signal activation.

Inhibitory effects of emodin, baicalin, schizandrin and berberine on hefA gene: treatment of Helicobacter pylori-induced multidrug resistance.

AIM: To investigate the inhibitory effects of emodin, baicalin, etc. on the hefA gene of multidrug resistance (MDR) in Helicobacter pylori (H. pylori). METHODS: The double dilution method was used to screen MDR H. pylori strains and determine the minimum inhibitory concentrations (MICs) of emodin, baicalin, schizandrin, berberine, clarithromycin, metronidazole, tetracycline, amoxicillin and levofloxacin against H. pylori strains. After the screened MDR stains were treated with emodin, baicalin, schizandrin or berberine at a 1/2 MIC concentration for 48 h, changes in MICs of amoxicillin, tetracycline, levofloxacin, metronidazole and clarithromycin were determined. MDR strains with reduced MICs of amoxicillin were selected to detect the hefA mRNA expression by real-time quantitative PCR. RESULTS: A total of four MDR H. pylori strains were screened. Treatment with emodin, baicalin, schizandrin and berberine significantly decreased the MICs of amoxicillin and tetracycline against some strains, decreased by 1 to 2 times, but did not significantly change the MICs of clarithromycin, levofloxacin, and metronidazole against MDR strains. In the majority of strains with reduced MICs of amoxicillin, hefA mRNA expression was decreased; one-way ANOVA (SPSS 12.0) used for comparative analysis, P < 0.05. CONCLUSION: Emodin, baicalin, schizandrin and berberine significantly decreased the MICs of amoxicillin and tetracycline against some H. pylori strains, possibly by mechanisms associated with decreasing hefA mRNA expression.

[Effects of matrine on proliferation and telomerase activity of colon cancer SW1116 cells].

OBJECTIVE: To investigate the effects of matrine on proliferation and telomerase activity of colon cancer SW1116 cells. METHODS: The proliferation inhibitory rate was evaluated by MTT assay. The telomerase activity was analyzed by TRAP-ELISA, and the expression of hTERT mRNA was determined by semi-quantitative RT-PCR. RESULTS: Matrine displayed strong proliferation inhibitory effect in a dose-and-time-dependent manner against SW1116 cells. Compared with control group, the telomerase activity and the expression of hTERT mRNA decreased significantly (P < 0.05 or P < 0.01) in matrine group. CONCLUSION: Matrine can inhibit the telomerase activity by depressing the expression of hTERT in SW1116 cells and inhibiting cell proliferation.