Feki-Tounsi Molka, Hamza-Chaffai Amel
Unit of Marine and Environmental Toxicology, IPEIS, Sfax University, PB 805, 3018, Sfax, Tunisia,
Environ Sci Pollut Res Int. 2014 Sep;21(18):10561-73. doi: 10.1007/s11356-014-2970-0. Epub 2014 Jun 4.
Bladder cancer is a significant disease, the rates of which have increased over the few last years. However, its etiology remains as yet undefined. Cadmium, a widespread environmental carcinogen that has received considerable interest, presents evidence as a possible cause of bladder cancer. A literature review was conducted from the years 1984-2013 to study the accumulated evidence for cadmium as a possible cause of bladder cancer, including routes of cadmium exposure, accumulation, toxicity, carcinogenicity, and evidence from epidemiological and experimental studies. Special reference is devoted to cadmium nephrotoxicity, which illustrates how cadmium exerts its effects on the transitional epithelium of the urinary tract. Mechanisms of carcinogenesis are discussed. The effects of cadmium on gene expression in urothelial cells exposed to cadmium are also addressed. Despite different methodologies, several epidemiologic and nephrotoxicity studies of cadmium indicate that occupational exposure to cadmium is associated with increased risk of bladder cancer and provide additional evidence that cadmium is a potential toxic element in urothelial cells. In vitro studies provide further evidence that cadmium is involved in urothelial carcinogenesis. Animal studies encounter several problems such as morphology differences between species. Among the complex mechanisms of cadmium carcinogenesis, gene expression deregulation is the subject of recent studies on bladder cadmium-induced carcinogenesis. Further research, however, will be required to promise a better understanding of the mechanisms underlying cadmium carcinogenesis and to establish the precise role of cadmium in this important malignancy.
膀胱癌是一种严重的疾病，其发病率在过去几年中有所上升。然而，其病因至今仍不明确。镉是一种广泛存在的环境致癌物，已受到广泛关注，有证据表明它可能是膀胱癌的病因。本文对1984年至2013年间的文献进行了综述，以研究镉作为膀胱癌可能病因的累积证据，包括镉的接触途径、蓄积、毒性、致癌性以及流行病学和实验研究的证据。特别提及了镉的肾毒性，它说明了镉如何对尿路的移行上皮发挥作用。文中讨论了致癌机制。还探讨了镉对暴露于镉的尿路上皮细胞基因表达的影响。尽管研究方法不同，但多项镉的流行病学和肾毒性研究表明，职业性接触镉与膀胱癌风险增加有关，并提供了额外证据证明镉是尿路上皮细胞中的一种潜在有毒元素。体外研究进一步证明镉参与了尿路上皮癌的发生。动物研究存在一些问题，如物种间的形态差异。在镉致癌的复杂机制中，基因表达失调是近期关于镉诱导膀胱癌发生的研究主题。然而，还需要进一步的研究来更好地理解镉致癌的潜在机制，并确定镉在这种重要恶性肿瘤中的精确作用。
