Background: The potassium voltage-gated channel subfamily Q member 1 (KCNQ1) gene has recently received much attention as a candidate susceptibility gene for type 2 diabetes mellitus, especially in Asian populations. We previously reported that Kcnq1 mutant mice exhibit reduced insulin secretion and hyperglycemia due to a decrease in pancreatic β-cell mass. Through in vivo and in vitro analyses, we ascertained that this mechanism is the result of the downregulation of the non-coding RNA ‘Kcnq1ot1,’ which is expressed in the paternal allele of the Kcnq1 gene region, causing an increase in the expression of the cell cycle inhibitor cyclin dependent kinase inhibitor 1C (Cdkn1c). It was found that decreased Kcnq1ot1 expression resulted in pancreatic β-cell failure; however, the degree of pancreatic β-cell volume reduction was not severe. Methods: We induced obesity in Kcnq1ot1 truncation mice by feeding them a high-fat diet and evaluated pancreatic β-cell mass. Results: In the present study, we reveal that CCAAT/enhancer binding protein beta (C/EBPβ), which is expressed at higher levels in pancreatic β-cells in obese individuals, further increases the expression of Cdkn1c, which is upregulated by the Kcnq1 gene mutation. We found that simultaneous Cdkn1c hypomethylation and C/EBPβ overexpression in pancreatic β-cells causes a synergistic decrease in pancreatic β-cell mass. Conclusion This finding suggests that the synergistic effect of genetic factors such as Kcnq1 gene mutations and environmental factors such as obesity and overeating, which lead to increased expression of C/EBPβ, contribute to the regulation of pancreatic β-cell mass. This study is the first to show that the Kcnq1 gene is related to pancreatic β-cell mass through genetic-environment interactions.

OBJECTIVE: Rikkunshito, an herbal medicine, is widely prescribed in Japan for the treatment of anorexia and functional dyspepsia, and has been reported to recover reductions in food intake caused by cisplatin. We investigated whether rikkunshito could improve chemotherapy-induced nausea and vomiting (CINV) and anorexia in patients treated with cisplatin. METHODS: Patients with uterine cervical or corpus cancer who were to receive cisplatin (50 mg/m² day 1) and paclitaxel (135 mg/m² day 0) as first-line chemotherapy were randomly assigned to the rikkunshito group receiving oral administration on days 0–13 with standard antiemetics, or the control group receiving antiemetics only. The primary endpoint was the rate of complete control (CC: no emesis, no rescue medication, and no significant nausea) in the overall phase (0–120 hours). Two-tailed p<0.20 was considered significant in the planned analysis. RESULTS: The CC rate in the overall phase was significantly higher in the rikkunshito group than in the control group (57.9% vs. 35.3%, p=0.175), as were the secondary endpoints: the CC rate in the delayed phase (24–120 hours), and the complete response (CR) rates (no emesis and no rescue medication) in the overall and delayed phases (63.2% vs. 35.3%, p=0.095; 84.2% vs. 52.9%, p=0.042; 84.2% vs. 52.9%, p=0.042, respectively), and time to treatment failure (p=0.059). Appetite assessed by visual analogue scale (VAS) appeared to be superior in the rikkunshito group from day 2 through day 6. CONCLUSION: Rikkunshito provided additive effect for the prevention of CINV and anorexia.
Administration, Oral ; Anorexia* ; Antiemetics ; Appetite ; Cisplatin* ; Drug Therapy ; Dyspepsia ; Eating ; Herbal Medicine* ; Humans ; Japan ; Nausea* ; Paclitaxel* ; Time-to-Treatment ; Vomiting*