職業性胆管がんリスク関連有機溶剤成分の発がん性に関する研究

抄録

　Recently, an outbreak of occupational bile duct cancer in young employees was reported in printing factories where 1,2-dichloropropane (1,2-DCP)-enriched cleaning solvents had been used for a long time in daily operation. Nevertheless, little is known about the relating carcinogenesis mechanisms. For the better understanding of cancer-causing risk of this industrial chemical, its carcinogenic property should be further addressed. However, contrary to tumor-initiating activity, there is little information about in vitro trials exploring whether 1,2-dichloropropane has tumor-promoting activity or not.

　In the present study, to examine the tumor-promoting activity of 1,2-DCP, we conducted in vitro cell transformation assay, one of the major alternatives to animal bioassays for the detection of carcinogenic potential. According to an authorized protocol by OECD with minor modifications, we employed Bhas 42 cells, a mouse cell line that has been considered to be a model of initiated cells, for promotion test. Our results show that 1,2-DCP could act as tumor-promoting agent, at least, in the culture system that mimics some key stages of in vivo multistep carcinogenesis. Together with our previous studies that focused on the potential mechanisms relating to the 1,2-DCP-associated occupational bile duct cancer in terms of metabolism and disposition (1, 2), our findings might provide a new route to better understanding of chemical hazard of 1,2-DCP.

(1) Toyoda et al., Sci Rep. 6:24586, 2016.

(2) Toyoda et al., Oxid. Med. Cell. Longev. 2017:9736836, 2017.