Abstract
Obesity is a risk factor for cancer and cancer-related mortality, however, its role in lung cancer progression remains controversial. This study aimed to assess whether high-fat diet (HFD)-induced obesity promotes lung cancer progression and whether the promotion can be decreased by Kanglaite injection (KLTI). In vivo, HFD-induced overweight or obesity increases the lung carcinoma incidence and multiplicity in a urethane-induced lung carcinogenic model and cancer-related mortality in a LLC allograft model by increasing oxidative stress and cellular signaling molecules including JAK, STAT3, Akt, mTOR, NF-κB and cyclin D1. These changes resulted in increases in vascular disruption and the lung water content, thereby promoting lung epithelial proliferation and the epithelial-mesenchymal transition (EMT) during carcinogenesis. Chronic KLTI treatment substantially prevented the weight gain resulting from HFD consumption, thereby reversing the metabolic dysfunction-related physiological changes and reducing susceptibility to lung carcinogenesis. In vitro, KLTI significantly suppressed the proliferation and induced apoptosis and differentiation in 3T3-L1 preadipocyte cells and attenuated endothelial cell permeability in HUVECs. Our study indicates that there is a potential relationship between obesity and lung cancer. This is the first study to show that obesity can directly accelerate carcinogen-induced lung cancer progression and that KLTI can decrease the lung cancer-promoting effect of HFD-induced obesity.