Population-based cohort study of diabetes mellitus and mortality in gastric adenocarcinoma

Berberine retarded the growth of gastric cancer xenograft tumors by targeting hepatocyte nuclear factor 4α

BACKGROUND

Gastric cancer is the third deadliest cancer in the world and ranks second in incidence and mortality of cancers in China. Despite advances in prevention, diagnosis, and therapy, the absolute number of cases is increasing every year due to aging and the growth of high-risk populations, and gastric cancer is still a leading cause of cancer-related death. Gastric cancer is a consequence of the complex interaction of microbial agents, with environmental and host factors, resulting in the dysregulation of multiple oncogenic and tumor-suppressing signaling pathways. Global efforts have been made to investigate in detail the genomic and epigenomic heterogeneity of this disease, resulting in the identification of new specific and sensitive predictive and prognostic biomarkers. Trastuzumab, a monoclonal antibody against the HER2 receptor, is approved in the first-line treatment of patients with HER2+ tumors, which accounts for 13%-23% of the gastric cancer population. Ramucirumab, a monoclonal antibody against VEGFR2, is currently recommended in patients progressing after first-line treatment. Several clinical trials have also tested novel agents for advanced gastric cancer but mostly with disappointing results, such as anti-EGFR and anti-MET monoclonal antibodies. Therefore, it is still of great significance to screen specific molecular targets for gastric cancer and drugs directed against the molecular targets.

AIM

To investigate the effect and mechanism of berberine against tumor growth in gastric cancer xenograft models and to explore the role of hepatocyte nuclear factor 4α (HNF4α)-WNT5a/β-catenin pathways played in the antitumor effects of berberine.

METHODS

MGC803 and SGC7901 subcutaneous xenograft models were established. The control group was intragastrically administrated with normal saline, and the berberine group was administrated intragastrically with 100 mg/kg/d berberine. The body weight of nude mice during the experiment was measured to assess whether berberine has any adverse reaction. The volume of subcutaneous tumors during this experiment was recorded to evaluate the inhibitory effect of berberine on the growth of MGC803 and SGC7901 subcutaneous transplantation tumors. Polymerase chain reaction assays were conducted to evaluate the alteration of transcriptional expression of HNF4α, WNT5a and β-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models. Western blotting and IHC were performed to assess the protein expression of HNF4α, WNT5a and β-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models.

RESULTS

In the both MGC803 and SGC7901 xenograft tumor models, berberine significantly reduced tumor volume and weight and thus retarded the growth rate of tumors. In the SGC7901 and MGC803 subcutaneously transplanted tumor models, berberine down-regulated the expression of HNF4α, WNT5a and β-catenin in tumor tissues from both transcription and protein levels. Besides, berberine also suppressed the protein expression of HNF4α, WNT5a and β-catenin in liver tissues.

CONCLUSION

Berberine retarded the growth of MGC803 and SGC7901 xenograft model tumors, and the mechanism behind these anti-growth effects might be the downregulation of the expression of HNF4α-WNT5a/β-catenin signaling pathways both in tumor tissues and liver tissues of the xenograft models.

Hyperglycemia induces miR-26-5p down-regulation to overexpress PFKFB3 and accelerate epithelial–mesenchymal transition in gastric cancer

Gastric cancer (GC) is one of the most deadly malignancies with high morbidity worldwide. Cancer cells exhibited higher level of glucose catabolism than normal cells to meet the needs for rapid growth. Emerging evidences indicated that hyperglycemia has positive effects on the progression of tumor. As a vital regulator of glycolysis, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) was confirmed to have a higher expression level in tumor tissue and correlated with the prognosis of GC patients. However, the role of PFKFB3 in GC patients with hyperglycemia remains unclear. The data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) were utilized to analyze the expression level of PFKFB3 and conducted survival analysis of GC patients. Western blot assay was used to detect gene expression at the protein level. Small interfering RNA (siRNA) transfection assay was conducted to down-regulate the expression of PFKFB3. Cell functional assays were carried out to reflect the ability of cell proliferation and migration. The results indicated that PFKFB3 was significantly upregulated and its overexpression was associated with poor prognosis of GC patients. Besides, hyperglycemia stimulated the higher expression of PFKFB3 along with the enhanced proliferation, migration and epithelial–mesenchymal transition (EMT) in GC cells. Knocking down of PFKFB3 effectively reversed the effects of high glucose concentration on GC malignant phenotype and the opposite results were gained when miR-26-5p was inhibited. Therefore, PFKFB3 down-regulated by miR-26-5p inhibited the malignant phenotype of GC with hyperglycemia.

Improved prognosis in gastric adenocarcinoma among metformin users in a population-based study

BACKGROUND

Metformin may improve the prognosis in gastric adenocarcinoma, but the existing literature is limited and contradictory.

METHODS

This was a Swedish population-based cohort study of diabetes patients who were diagnosed with gastric adenocarcinoma in 2005-2018 and followed up until December 2019. The data were retrieved from four national health data registries: Prescribed Drug Registry, Cancer Registry, Patient Registry and Cause of Death Registry. Associations between metformin use before the gastric adenocarcinoma diagnosis and the risk of disease-specific and all-cause mortality were assessed using multivariable Cox proportional hazard regression. The hazard ratios (HRs) and 95% confidence intervals (CIs) were adjusted for sex, age, calendar year, comorbidity, use of non-steroidal anti-inflammatory drugs or aspirin, and use of statins.

RESULTS

Compared with non-users, metformin users had a decreased risk of disease-specific mortality (HR 0.79, 95% CI 0.67-0.93) and all-cause mortality (HR 0.78, 95% CI 0.68-0.90). The associations were seemingly stronger among patients of female sex (HR 0.66, 95% CI 0.49-0.89), patients with tumour stage III or IV (HR 0.71, 95% CI 0.58-0.88), and those with the least comorbidity (HR 0.71, 95% CI 0.57-0.89).

CONCLUSIONS

Metformin use may improve survival in gastric adenocarcinoma among diabetes patients.

Predictors of Remission and Relapse of Diabetes after Conventional Gastrectomy for Gastric Cancer: Nationwide Population-Based Cohort Study

BACKGROUND

We investigated whether preoperative clinical parameters predict diabetes remission and relapse after conventional gastrectomy for cancer and whether postoperative weight changes influence diabetes remission and relapse.

STUDY DESIGN

This study included 5,150 patients with diabetes who underwent gastrectomy for cancer from 2004 to 2014. Diabetes remission was defined in 3 ways, according to postoperative antidiabetic medication and fasting plasma glucose (FPG) levels. Diabetes relapse was defined as reinitiating antidiabetic medication among patients in diabetes remission.

RESULTS

Six predictors (higher body mass index [BMI], total gastrectomy, younger age, FPG levels, number of oral hypoglycemic agents [OHAs], and no insulin use) of diabetes remission increased the likelihood of remission by >13-fold (odds ratio [OR], 13.67; 95% confidence interval [CI], 8.65‒19.11). Three factors (younger age, lower FPG levels, and use of only 1 OHA) predicted a 58% decreased likelihood of diabetes relapse (hazard ratio, 0.42; 95% CI 0.35‒0.48). The lowest interval of postoperative BMI decrease (<-20%) showed a >3-fold increased likelihood of diabetes remission than the highest interval (≥-5%; OR 3.14; 95% CI 2.08‒4.75), independent of baseline BMI.

CONCLUSIONS

Six variables (BMI, type of gastrectomy, age, FPG levels, number of OHAs used, and insulin use/non-use), and 3 variables (age, FPG levels, number of OHAs used) significantly predict diabetes remission and relapse after gastrectomy for cancer, respectively. Greater postoperative weight decrease may increase the likelihood of diabetes remission, independent of baseline weight. Our results may serve as a basis for the establishment of diabetes and weight management strategies after conventional gastrectomy for cancer.

Hyperglycemia promotes Snail-induced epithelial-mesenchymal transition of gastric cancer via activating ENO1 expression

Background

Gastric cancer (GC) is one of the most common gastrointestinal malignancies worldwide. Emerging evidence indicates that hyperglycemia promotes tumor progression, especially the processes of migration, invasion and epithelial-mesenchymal transition (EMT). However, the underlying mechanisms of GC remain unclear.

Method

Data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were used to detect the expression of glycolysis-related enzymes and EMT-related transcription factors. Small interfering RNA (siRNA) transfection was performed to decrease ENO1 expression. Immunohistochemistry (IHC), Western blot and qRT-PCR analyses were used to measure gene expression at the protein or mRNA level. CCK-8, wound-healing and Transwell assays were used to assess cell proliferation, migration and invasion.

Results

Among the glycolysis-related genes, ENO1 was the most significantly upregulated in GC, and its overexpression was correlated with poor prognosis. Hyperglycemia enhanced GC cell proliferation, migration and invasion. ENO1 expression was also upregulated with increasing glucose concentrations. Moreover, decreased ENO1 expression partially reversed the effect of high glucose on the GC malignant phenotype. Snail-induced EMT was promoted by hyperglycemia, and suppressed by ENO1 silencing. Moreover, ENO1 knockdown inhibited the activation of transforming growth factor β (TGF-β) signaling pathway in GC.

Conclusions

Our results indicated that hyperglycemia induced ENO1 expression to trigger Snail-induced EMT via the TGF-β/Smad signaling pathway in GC.