Ursodeoxycholic acid (UDCA) can prevent chemical and colitis-associated colon carcinogenesis by unknown mechanism(s). One of the processes underlying the chemopreventive action could be the inhibition of proliferation by UDCA. To clarify the antiproliferative mechanism of UDCA, we used p53 wt colon carcinoma cell lines HCT8 and HCT116.
View Article and Find Full Text PDFThe role of mismatch repair (MMR) in the response of colon carcinoma cells to 5-fluorouracil (5FU) is not well understood. In most of the in vitro studies only short-term response was investigated. We focussed here on the influence of MMR status on the mechanism of the short- and long-term response to clinically relevant 5FU concentrations by using isogenic or semiisogenic cell line pairs expressing/nonexpressing the hMLH1 protein, an important component of the MMR system.
View Article and Find Full Text PDFUrsodeoxycholic acid (UDCA) attenuates colon carcinogenesis in humans and in animal models by an unknown mechanism. We investigated UDCA effects on normal intestinal epithelium in vivo and in vitro to identify the potential chemopreventive mechanism. Feeding of mice with 0.
View Article and Find Full Text PDFAcute kidney injury (AKI) is associated with significant morbidity and mortality. Its prevalence is increasing. Risk factors are older age, diabetes, atherosclerosis, medications, heart failure, male sex, and even mild chronic renal failure.
View Article and Find Full Text PDFThe role of the mismatch repair (MMR) system in correcting base-base mismatches is well established; its involvement in the response to DNA double strand breaks, however, is less clear. We investigated the influence of the essential component of MMR, the hMLH1 protein, on the cellular response to DNA-double strand breaks induced by treatment with SN-38, the active metabolite of topoisomerase I inhibitor irinotecan, in a strictly isogenic cell system (p53(wt), hMLH1(+)/p53(wt), hMLH1(-)). By using hMLH1 expressing clones or cells transduced with the hMLH1-expressing adenovirus as well as siRNA technology, we show that in response to SN-38-induced DNA damage the MMR proficient (MMR(+)) cells make: (i) a stronger G2/M arrest, (ii) a subsequent longer tetraploid G1 arrest, (iii) a stronger activation of Chk1 and Chk2 kinases than the MMR deficient (MMR(-)) counterparts.
View Article and Find Full Text PDF