ABSTRACT
Objective To investigate the regeneration and differentiation of HOCs in the 2-AAF/PHx rat models. To explore the expression of Cyr61and its mechanism in differentiation of HOCs in vitro. Methods In 2-AAF/PHx rats model,induction and expansion of HOCs were detected by immunochemistry and HE staining. West-ern blot was used for observing the expression of Cyr61. Furthermore,the expression of Cyr61 andβ-catenin were detected by Western blot in differentiation of WB-F344 cells in vitro. Results Cyr61 protein level increased as a re-sult of HOCs in rats livers after 2-AAF/PHx. In addition,the expression of Cyr61 and β-catenin significantly in-creased during WB-F344 cells differentiation in vitro. Conclusions Cyr61 might play an important role as a signal-ing mediator in HOCs response and closely correlate with Cyr61 andβ-catenin in proliferation and differentiation of HOCs.
ABSTRACT
AIM To study the cancer promoting effects of N nitrosodiethylamine (DEN) and 2 Acetylaminofluorene (2 AAF). METHODS Medium Term Rat Liver Bioassay (MTRLB). Male SD rats were initially given a single dose (200 mg?kg -1 ) of DEN ip and starting 2 weeks later, were treated with 10, 33 and 100 ppm DEN in drinking water, or with 2 2, 6 6 and 22 mg?kg -1 2 AAF by gavage for 6 weeks. All rats were subjected to two thirds partial hepatectomy at week 3 and killed at the end of week 8. Carcinogenic potential was scored by comparing the numbers and areas in induced glutathione S transferase placental form (GST P) positive foci in the liver with those of corresponding control group given DEN alone. RESULTS Both DEN and 2 AAF caused the increases of the numbers and areas of GST P positive foci in the liver, and showed dose response relationship. CONCLUSION Both DEN and 2 AAF shows cancer promoting effects, and MTRLB was a convenient, economical and effective tool to study the cancer promoting effects of test chemicals.