[Study of ceramide monohexoside in ovarian cell line COC1/DDP resistant to cisplantin].

Objective: To investigate the effect of ceramide monohexoside (CMH) on resistance to cisplatin and apoptosis in ovarian cell line COC1/DDP, and to provide new ideals and clues to seek new effective methods for studying the mechanism and reversing the resistance in ovarian cell line as well.

Methods: COC1 cells and COC1/DDP cells (before and after the treatment of mifepristone) were collected and neutral glycosphingolipids (N-GSLs) of the cells was isolated and purified, changes of CMH content were analyzed by high performance thin layer chromatography (HPTLC). The COC1/DDP cells were divided into three groups, one treated by cisplatin, one treated by mifepristone, the other treated by cisplatin and mifepristone.

Comparing the base usage frequency between bacteria DNA double strand.

During the Evolution, effected by select pressure or nature mutation, the compositions of bacteria genomes is various. And many experiences prove that the genes between leading strand and lagging strand is distinctly in copy, transcription and repair. Some scholars presume that the bases distribution is difference between the two strand, to verify the guess, we using the technology of bioinformatics, compare the base usage between the DNA double strand in 17 species bacteria.

[Enhanced sensitivity of ovarian cell line to cisplatin induced by mifepristone and its mechanism].

Objective: To observe the effect of mifepristone in enhancing chemosensitivity of drug-resistant ovarian cancer cell line to cisplatin and investigate its mechanism.

Methods: Human ovarian cancer cell lines COC1 (DDP-sensitive) and COC1/DDP (DDP-resistant) were incubated with or without mifepristone. The proliferation rate of the cells was determined by methyl thiazolyl tetrazolium (MTT) assay and positive expression of apoptosis-associated proteins Bcl-2 and Bax were observed by means of flow cytometry.