Inhibition of STRA6 suppresses NSCLC growth via blocking STAT3/SREBP-1c axis-mediated lipogenesis.

Dysregulation in lipid metabolism is among the most prominent metabolic alterations in cancer. Stimulated by retinoic acid 6 (STRA6), a vitamin A transporter has shown to be involved in the pathogenesis of cancers. Nevertheless, the function of STRA6 in non-small cell lung cancer (NSCLC) progression remains undefined. We obtained cancer and adjacent tissues from NSCLC patients and conducted functional experiments on STRA6 on NSCLC cell lines and mice. High STRA6 expression is correlated with poor prognosis in patients with NSCLC. Results from in vitro and in vivo animal studies showed that STRA6 knockdown suppressed the proliferation, migration, and invasion of NSCLC cells in vitro and tumor growth in vivo through regulation of lipid synthesis. Mechanistically, STRA6 activated a Janus kinase 2/signal transducer and activator of transcription 3 (JAK2-STAT3) signaling cascade which inducing the expression of STAT3 target gene. By inducing the expression of the target gene of STAT3, sterol regulatory element binding protein 1 (SREBP-1), STRA6 promotes SREBP-1-mediated adipogenesis and provides energy for NSCLC cell growth. Our study uncovers a novel STRA6/STAT3/SREBP-1 regulatory axis that enhances NSCLC metastasis by reprogramming of lipid metabolism. These results demonstrate the potential use of STRA6 as a biomarker for diagnosing NSCLC, which may therefore potentially serve as a therapeutic target for NSCLC.

Measures of insulin resistance and beta cell function before and after treatment of HCV infection.

The association between chronic HCV infection and type 2 diabetes mellitus (T2DM) has been established; however, there is limited research on ß-cell function particularly in the pre-diabetic population. Here, we evaluated indices of ß-cell function and insulin sensitivity across the spectrum from normal glucose tolerance to T2DM in individuals with and without chronic hepatitis C (CHC), and the effects of antiviral treatments on these variables. A total of 153 non-cirrhotic, non-fibrotic CHC patients with a BMI <25 were enrolled in the study. Among them, 119 were successfully treated with either direct acting antiviral (DAA) drugs or pegylated interferon/ribavirin (IFN/RBV) anti-HCV therapy. Fasting state- and oral glucose tolerance test (OGTT)-derived indexes were used to evaluate ß-cell function and insulin sensitivity. Among all subjects, 19 (13%) had T2DM and 21% exhibited pre-diabetes including 8% isolated impaired fasting glucose (IFG) and 13% combined IFG and impaired glucose tolerance (IGT). Early and total insulin secretion adjusted for the degree of insulin resistance were decreased in pre-diabetic CHC patients compared to HCV-uninfected individuals. Viral eradication through DAA or IFN/RBV therapy demonstrated positive impacts on insulin sensitivity and ß-cell function in CHC patients who achieved sustained virologic response (SVR), regardless of fasting or OGTT state. These findings emphasize the role of HCV in the development of ß-cell dysfunction, while also suggesting that viral eradication can improve insulin secretion, reverse insulin resistance, and ameliorate glycemic control. These results have important implications for managing pre-diabetic CHC patients and could prevent diabetes-related clinical manifestations and complications.