Cancer is currently one of the major causes of death in patients with type 2 diabetes mellitus. We previously reported the beneficial effects of the glucagon-like peptide-1 receptor agonist exendin-4 against prostate and breast cancer. In the present study, we examined the anti-cancer effect of the sodium-glucose cotransporter 2 (SGLT2) inhibitor ipragliflozin using a breast cancer model. In human breast cancer MCF-7 cells, SGLT2 expression was detected using both RT-PCR and immunohistochemistry. Ipragliflozin at 1-50 μM significantly and dose-dependently suppressed the growth of MCF-7 cells. BrdU assay also revealed that ipragliflozin attenuated the proliferation of MCF-7 cells in a dose-dependent manner. Because the effect of ipragliflozin against breast cancer cells was completely canceled by knocking down SGLT2, ipragliflozin could act via inhibiting SGLT2. We next measured membrane potential and whole-cell current using the patch clamp technique. When we treated MCF-7 cells with ipragliflozin or glucose-free medium, membrane hyperpolarization was observed. In addition, glucose-free medium and knockdown of SGLT2 by siRNA suppressed the glucose-induced whole-cell current of MCF-7 cells, suggesting that ipragliflozin inhibits sodium and glucose cotransport through SGLT2. Furthermore, JC-1 green fluorescence was significantly increased by ipragliflozin, suggesting the change of mitochondrial membrane potential. These findings suggest that the SGLT2 inhibitor ipragliflozin attenuates breast cancer cell proliferation via membrane hyperpolarization and mitochondrial membrane instability.

BackgroundAlthough incretin therapy is clinically available in patients with type 2 diabetes undergoing hemodialysis, no study has yet examined whether incretin therapy is capable of maintaining glycemic control in this group of patients when switched from insulin therapy. In this study, we examined the efficacy of incretin therapy in patients with insulin-treated type 2 diabetes undergoing hemodialysis.MethodsTen type 2 diabetic patients undergoing hemodialysis received daily 0.3 mg liraglutide, 50 mg vildagliptin, and 6.25 mg alogliptin switched from insulin therapy on both the day of hemodialysis and the non-hemodialysis day. Blood glucose level was monitored by continuous glucose monitoring. After blood glucose control by insulin, patients were treated with three types of incretin therapy in a randomized crossover manner, with continuous glucose monitoring performed for each treatment.ResultsDuring treatment with incretin therapies, severe hyperglycemia and ketosis were not observed in any patients. Maximum blood glucose and mean blood glucose on the day of hemodialysis were significantly lower after treatment with liraglutide compared with treatment with alogliptin (p < 0.05), but not with vildagliptin. The standard deviation value, a marker of glucose fluctuation, on the non-hemodialysis day was significantly lower after treatment with liraglutide compared with treatment with insulin and alogliptin (p < 0.05), but not with vildagliptin. Furthermore, the duration of hyperglycemia was significantly shorter after treatment with liraglutide on both the hemodialysis and non-hemodialysis days compared with treatment with alogliptin (p < 0.05), but not with vildagliptin.ConclusionsThe data presented here suggest that patients with type 2 diabetes undergoing hemodialysis and insulin therapy could be treated with incretin therapy in some cases.

Low endogenous testosterone and sex hormone-binding globulin (SHBG) concentrations have been reported to be associated with metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD). However, little is known about the relationships between testosterone or SHBG and liver fibrosis in NAFLD. Thus, we aimed to clarify the relationships between serum testosterone or SHBG concentration and fibrosis-4 (FIB-4) index, a marker of liver fibrosis. Serum testosterone was assayed in various forms (total testosterone [TT], calculated free testosterone [cFT], calculated bioavailable testosterone [cbT], and SHBG) and metabolic markers were also measured in 363 Japanese men (mean age 51.1 ± 8.7 years) at routine health examinations. We then attempted to identify the factors contributing to liver fibrosis by investigating the associations between the metabolic markers, including testosterone, and FIB-4 index. People with a relatively high FIB-4 index (≥1.3) demonstrated lower cFT, cbT, homeostasis model assessment (HOMA)-β, low-density lipoprotein-cholesterol, and blood urea nitrogen, but higher SHBG, than those with a lower FIB-4 index (<1.3). There were no significant differences in HbA1c, fasting glucose concentration, HOMA-R, or metabolic syndrome prevalence between the two groups. Binary regression analysis revealed that SHBG ≥52 nmol/L and cFT <8.0 ng/dL were statistically significant risk factors for FIB-4 index ≥1.3. Receiver operating characteristic analysis revealed that cFT <7.62 ng/dL (area under the curve [AUC] = 0.639) and SHBG ≥49.8 nmol/L (AUC = 0.649) were the strongest risk factors for FIB-4 index ≥1.3. In contrast to previous findings showing low SHBG concentrations in NAFLD, we provide evidence that high SHBG and low bioactive testosterone are associated with liver fibrosis.

Aims/Introduction Incretin therapy is a common treatment for type 2 diabetes mellitus. We have previously reported an anti‐prostate cancer effect of glucagon‐like peptide‐1 receptor (GLP‐1R) agonist exendin‐4. The attenuation of cell proliferation in the prostate cancer cell line was dependent on GLP‐1R expression. Here, we examined the relationship between human prostate cancer severity and GLP‐1R expression, as well as the effect of forced expression of GLP‐1R using a lentiviral vector. Materials and Methods Prostate cancer tissues were extracted by prostatectomy and biopsy. GLP‐1R was overexpressed in ALVA‐41 cells using a lentiviral vector (ALVA‐41‐GLP‐1R cells). GLP‐1R expression was detected by immunohistochemistry and quantitative polymerase chain reaction. Cell proliferation was examined by growth curves and bromodeoxyuridine incorporation assays. Cell cycle distribution and regulators were examined by flow cytometry and western blotting. In vivo experiments were carried out using a xenografted model. Results GLP‐1R expression levels were significantly inversely associated with the Gleason score of human prostate cancer tissues. Abundant GLP‐1R expression and functions were confirmed in ALVA‐41‐GLP‐1R cells. Exendin‐4 significantly decreased ALVA‐41‐GLP‐1R cell proliferation in a dose‐dependent manner. DNA synthesis and G1‐to‐S phase transition were inhibited in ALVA‐41‐GLP‐1R cells. SKP2 expression was decreased and p27Kip1 protein was subsequently increased in ALVA‐41‐GLP‐1R cells treated with exendin‐4. In vivo experiments carried out by implanting ALVA‐41‐GLP‐1R cells showed that exendin‐4 decreased prostate cancer growth by activation of GLP‐1R overexpressed in ALVA41‐GLP‐1R cells. Conclusions Forced expression of GLP‐1R attenuates prostate cancer cell proliferation by inhibiting cell cycle progression in vitro and in vivo. Therefore, GLP‐1R activation might be a potential therapy for prostate cancer.

DECREASED ANDROGEN LEVELS associated with aging cause various symptoms, termed late-onset hypogonadism (LOH) [1][2][3]. LOH is characterized by (i) somatovegetative symptoms and conditions, including weakness, fatigue, sleep disturbance, visceral obesity, sarcopenia and osteopenia (or osteoporosis), (ii) psychological symptoms, including disturbed sense of well-being, depressed mood, irritability and anxiety and (iii) sexual symptoms, including decreased libido and erectile dysfunction.Visceral obesity has been proposed to be caused by vice circulation. Specifically, decreased androgen lev-A higher score on the Aging Males' Symptoms scale is associated with insulin resistance in middle-aged men Abstract. An age-associated androgen decrease and its pathological conditions are defined as late-onset hypogonadism (LOH). Among the various symptoms associated with LOH, a visceral fat increase is strongly associated with relatively low levels of testosterone. However, few studies have investigated the relationship between the Aging Males' Symptoms (AMS) scores and metabolic abnormalities. Thus, we aimed to clarify this relationship by investigating the relationship between AMS scores and various markers in blood. During routine health examinations in 241 middle-aged males (52.7±7.5 years of age, mean±SD), 150 males (62.2%) displayed higher AMS values than normal. No statistical association was observed between total AMS scores and any testosterone value. All mental, physical and sexual AMS subscales were significantly positively correlated with insulin levels and HOMA-IR. Only sexual subscale scores were significantly inversely associated with free or bioavailable testosterone level. Males with insulin resistance (HOMA-IR≥2.5) demonstrated significantly higher AMS scores than those with normal insulin sensitivity (HOMA-IR<2.5). AMS values were positively correlated with fasting blood glucose, insulin and HOMA-IR values. Interestingly, univariate and multivariate analyses revealed that HOMA-IR≥2.5 was a significant predictor for detection of moderately severe AMS values (AMS≥37), whereas AMS≥37 was not a predictor of metabolic syndrome by International Diabetes Federation (IDF) criterion. In conclusion, almost 60% of healthy male subjects displayed abnormal AMS scores. AMS values were not associated with testosterone values but rather were related to insulin resistance, particularly in subjects with moderately severe AMS values. Insulin resistance-related general unwellness might be reflected by AMS values.Key words: Testosterone, Late-onset hypogonadism, Insulin resistance, Metabolic syndrome els result in visceral obesity, which then leads to the suppression of gonadotropin and subsequent testosterone deficiency [4]. We have reported that male ARKO mice develop visceral obesity because of decreased energy expenditure [5]. Metabolic syndrome (MetS) is characterized by multiple cardiovascular risk complications, including visceral obesity, hypertension, glucose tolerance and dyslipidemia. MetS incidence is rapidly incre...