目的:探讨低频超声终止妊娠的可能性并观察低频聚焦超声辐照兔胚胎后胎盘组织细胞c-fos m R N A的表达改变。方法:低频聚焦超声7种声强各60s体内直接照射妊娠第10天兔胚胎,妊娠20d时观察各组胚胎死亡率;选用完全抗孕剂量(45W/cm2×60s)照射胚胎,照后24、48、72、96h留取胎盘,原位杂交技术检测各组c-fosm R N A表达情况。结果:假照组胚胎死亡率为13.33%(8/60),照射组中声强30W/cm2、35W/cm2及≥40W/cm2组的胚胎死亡率分别为25.00%(12/48)、72.88%(43/59)和100%(64/64、43/43、40/40、35/35)。低频聚焦超声辐照胚胎后24h胎盘组织细胞c-fos m R N A表达增加,72h增加最明显,96h表达下降。结论:低频超声抗早孕具有潜在的可行性,辐照胚胎可诱导胎盘组织细胞c-fos m R N A表达增加。
Objective： To evaluate the expression of p16INK4A gene in ovarian cancer and analyze the relation between this alteration and the promoter methylation of p16INK4A DNA. Methods： Seven ovarian cancer cell lines and eighteen ovarian cancer specimens were selected for the study. Genomic DNA and RNA were extracted from fresh tissues and cell lines, DNA was treated with sodium bisulfite and then analyzed with methylation-specific PCR （MSP） to detect p16INK4A methylation. The expression of p16INK4A mRNA was detected by reverse transcription-polymerase chain reaction （RT-PCR）. In addition, the proliferation of methylated cell lines before and after treatment of demethylating agent 5-Aza-2＇-deoxycytidine （5-ADC） was examined with 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT） assay in vivo. Results： Compared with the control, the expression of p16INK4A mRNA decreased significantly or absolutely defaulted in 10 of 18 （55.56%） ovarian cancer specimens and 71.4% （5/7） ovarian cancer cell lines （P〈0.05）, and the expression of p16INK4A protein also decreased （P〈0.05）. The decrease of p16INK4A was due, in part, to p16INK4A methylation, which was found in the first exon of three cell lines and six ovarian cancer specimens and the rate was 42.86% and 33.33% in ovarian cancer cell lines and specimens respectively. All the methylated cells and tissues showed expression defect of p16INK4A, but the treatment of 5-ADC reactivated the expression of p16INK4A in methylated cells and decreased the proliferation of tumor cells in vitro and in vivo. Conclusion： The expression defect of p16INK4A gene possibly has an important role in the development of ovarian cancer, and this alteration is due, in part, to the methylation of the first exon in p16INK4A.
