Targeting SIRT3 signaling alleviates lung carcinoma progression by reducing hyperinsulinemia in postmenopausal obese mice: Protective intervention of betaxanthin

Abstract

Metabolic disturbances associated with obesity increase the risk and advancement of various tumor forms, including postmenopausal lung cancer, in humans. Betaxanthin, a type of yellow-orange pigment found in certain plants, particularly in some flowers, fruits, and vegetables, can be utilized to inhibit the growth of tumors and lessen the metabolic dysfunctions brought on by obesity. However, the functional role of betaxanthin (BET) in suppressing lung cancer progression and its potential mechanisms are still not fully understood. In this study, we examined the regulation of BET in obese mice with postmenopausal lung cancer receiving a high-fat diet (HFD). Initially, we found that BET could significantly mitigate the metabolic dysfunction that a high-fat diet causes in mice. Improved histological changes in the mammary fat pad, lower hepatic lipid deposition, and improved glucose tolerance and insulin resistance demonstrated this. Following that, BET treatment inhibited the formation of lung neoplasms in in-situ cancer animal models that were stimulated by HFD. Furthermore, in a postmenopausal mouse model fed HFD, BET significantly reduced the growth of pre-existing lung tumors, as well as attenuating metabolic abnormalities. Notably, in vitro research revealed that BET co-culture significantly reduced the proliferation and migration of mouse lung cancer cells, whereas insulin exposure increased these processes. Research on animals verified that lung cancer progressed due to hyperinsulinemia; however, BET treatment might inhibit this condition in postmenopausal mice on a high-fat diet. BET could up-regulate sirtuin 3 (SIRT3) expression levels in tumor, liver, and mammary fat pad tissues in postmenopausal mice with HFD-induced obesity, according to a bioinformatic and molecular biology study. Crucially, eradicating SIRT3 expression completely eliminated BET’s inhibitory effects on insulin-stimulated cancer cell proliferation and migration. This suggests that increasing SIRT3 expression may be required for BET to perform its anti-tumor function against lung cancer in conditions of hyperinsulinemia. Our findings showed that by modifying SIRT3 signaling, BET consumption is probably effective in the prevention and treatment of obesity-related lung cancer.

Keywords

• Betaxanthin
• Lung cancer
• Obesity
• Hyperinsulinemia
• SIRT3