[Research progress of mouse model of hepatitis B virus infection]

Hepatitis B virus (HBV) infection is a global health problem. Animal models are important for the study of the HBV infection mechanism. In the study related to the mouse model of HBV infection, the researchers have established a variety of mouse models, including transgenic, plasmid hydrodynamic injection, virus vector transfection, cccDNA cycle simulation, human and mouse liver chimerism, and liver/immune dual humanization, according to the characteristics of HBV infection. Herein, the research progress of these models is summarized. Notably, the application of these models can further clarify the mechanism of HBV infection under the conditions of a specific immune response in vivo and lay the foundation for the development of new antiviral drugs and immunotherapy for HBV infection.

The induction of multidrug resistance in human cervical carcinoma cell lines by estrogenic hormones

The role of estrogenic hormones on the induction of drug resistance was studied in cervical cancer cell lines, SiHa and Caski. After the cells were inoculated with estradiol (E2) or diethylstilbestrol (DES) in various dosages, the cell survival rates with adriamycin treatment were examined by MTT (3-[4,5-dimethyl-thiazole-2-yl]-2,5-diphenyl-tetrazolium-bromide) test and the intracellular accumulation of adriamycin was evaluated by flow cytometry. In the same condition, the expression of multidrug resistance gene-1 (mdr-1 gene) was detected either by Northern blot hybridization for mdr-1 mRNA or by immunoblot for P-glycoprotein 170. The data in this study indicated that estrogenic hormones had the capacity to induce drug resistance in cervical carcinoma cell lines. When cells were treated with estrogenic hormones and adriamycin simultaneously, the intracellular accumulation of adriamycin declined and corresponded with the drug resistance. Since the expression of the mdr-1 gene induced by E2 or DES results in drug resistance, it is suggested that the mdr-1 gene in SiHa cells may contain the estrogenic responsive element (ERE) in its regulatory region. However, the mechanism of drug resistance induced by estrogenic hormones in Caski cells is different from SiHa cells due to the absence of mdr-1 gene expression. Despite that, this experiment may provide a model to investigate the relationships between estrogenic hormones and drug resistance in other female genital cancers.