RESUMO
Visceral obesity is characterized by increased risk of cardiovascular disease as well as higher incidence of malignancies, including colorectal cancer (CRC), although the mechanisms linking excess adiposity with cancer are only partly characterized. Visceral obesity is currently acknowledged as a chronic inflammatory disorder and a growing body of evidence demonstrates the interconnections between obesity-related secretion pattern of adipo/cytokines and CRC. Specific molecules derived from the visceral adipose tissue (VAT), including adiponectin, leptin and resistin, are able to establish a positive feedback loop, thus increasing the proinflammatory and insulin resistant state and promoting tumorigenesis. Interestingly, these molecules have emerged as novel prognostic factors and therapeutic targets. This review will focus on current molecular and clinical evidence linking VAT-related inflammation to CRC initiation and progression, and summarize the role of dietary factors and lifestyle interventions aimed at promoting weight control and physical activity on CRC prevention and prognosis.
Assuntos
Neoplasias Colorretais/etiologia , Inflamação/etiologia , Obesidade/complicações , Adipocinas/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/mortalidade , Citocinas/metabolismo , Humanos , Inflamação/metabolismo , Resistência à Insulina , Gordura Intra-Abdominal/metabolismo , Doenças Vasculares/etiologia , Doenças Vasculares/metabolismoRESUMO
Breast cancer is more frequent in human nulliparae, whereas its incidence is reduced by early fullterm pregnancy. Rodent studies suggest that chorionic gonadotropin secretion during pregnancy affords protection by inducing breast structure differentiation. Opposite effects, however, have been observed in cancer prone transgenic mice overexpressing the ß subunit of chorionic gonadotropin or pituitary luteinic hormone (LH). Here we assessed the effect of administration of human chorionic gonadotropin (hCG) for 21 days (corresponding to the duration of a mouse pregnancy) in virgin female mice transgenic for the activated rat (r-) ERBB-2 oncogene (BALB-neuT). In these mice, the onset of atypical mammary duct hyperplasia and its progression towards multiple mammary carcinomas is accelerated by hCG. hCG enhances the in vitro proliferation and in vivo metastatization of tumor cells from a BALB-neuT mammary tumor expressing the hCG/LH as well as the ERBB-2 receptors. These findings suggest that hCG favours the growth and progression of hCG/LH and ERBB-2 receptor-positive breast tumors.