| Choriocarcinoma is a gestational trophoblastic tumor secondary tonormal or abnormal pregnancy. Choriocarcinoma is divided into gestationalchoriocarcinoma and non-gestational choriocarcinoma.It has a higherincidence rate in China and southeast Asian countries, of which50%occur inhydatidiform mole,25%in the abortion,22.5%in full-term pregnancy and2.5%in ectopic pregnancy. Choriocarcinoma mostly occurs in reproductiveperiod age, and there are a few occur in postmenopausal. Beforechemotherapy drugs produced, with high degree of malignancy the mortalityof this disease was90%or more. The treatments now are mainly orchemotherapy combined with operation therapy. Normal trophoblast hasstrong ability of proliferation. Tumor deriving from the trophoblast has astrong ability of proliferation and division. In recent years, parts of patients inthe course of chemotherapy have resistance, and the resistance of refractorychoriocarcinoma prognosis is poor.MicroRNAs with the length of～22nucleotide are a growing family ofsmall non-proten-coding RNAs whose function are just as post-transcriptionalregulators of target genes and are processed from longer precursors that formstem-loop hairpin structures via Dicer in animals or Dicer-like in plants. Theycan regulate the gene transcription expression through with the target mRNAspecific base pairing causing target mRNA degradation or inhibition of thetranslation. MiRNAs play an important role in the growth of the organism, cellproliferation, differentiation and apoptosis and many other life events. MiR-24is widely present in mammalian tissue and mostly regulates cell growth andapoptosis. In recent years, research related to miRNA and tumor has become ahot research topic. MiR-24is widely present in mammalian tissues withsequence of5'-UGGCUCAGUUCAGCAGGAACAG-3', first founded byLagos-Quintanazai[1]in the spine and vertebrates in2001. Researches have shown that human miR-24expresses as miR-24-1and miR-24-2, whichrespectively positioned at number ninth and nineteenth chromosome. In thehuman genome, miR-24-1,miR-23b and miR-27b form a gene cluster.miR-24-2,miR-27a and miR-23a shape another gene cluster. While miR-24-1and miR-24-2in the mouse genome are respectively positioned at the eighthand thirteenth chromosome[2]. The function of miRNA is mainly to regulatethe growth and apoptosis of the cell. Researches also show that MiR-24incervical cancer Hela cells has the function to inhibit cell growth and promoteapoptosis[3].Transforming growth factor beta is a cytokine super family withextensive biological activity which is newly discovered. At least four subtypeswhich are TGF beta1, TGF beta2, TGF beta3and TGF beta1beta2, can befound in Mammals.TGF beta1plays a role mainly in the human body. Thesignal is mediated by the family of Smads.TGF beta signaling is transmittedfrom cellular surface to nucleus by Smad proteins, of which there are threefunctional classes. The receptor-regulated Smads are composited ofSmads1,5and8mediate BMP signaling pathways,Smads2and3,transducesignals from TGF-βs and Activins.Common mediator smad led by Smad4complexes with receptor-regulated Smads to transcribe target genes inresponse to either TGF-β/Activin or BMPs signals.The inhibitory Smads arenegative regulators of TGF-β signaling.It is found by Sun[2]that TGF betainhibit miR-24transcription via Smad binding site.This paper aims to explore the miR-24on JEG-3of choriocarcinoma cellapoptosis mechanism.Objective: Detection of miR-24expression in choriocarcinoma JEG-3cell lines and exploration miR-24proliferation or apoptosis on JEG-3cells ofchorioepithelioma through the TGF beta1inhibit expression of miR-24.Methods: At37centi-degree,5%(volume fraction) CO2,JEG-3chorioc-arcinoma cell culture is put in fetal bovine serum on1640culture mediumcontaining15%(volume fraction).Logarithmic growth phase cells weredivided into two groups,one to join TGF beta1processing, the final concentra -tion of100ng/ml, a group of disregard, each with different time points24h,48h was divided into two subgroups. A collection of cells, according to Redzolone-step method fortotal RNA extraction kit for extracting total RNA, Thenreverse cDNA synthesis, real-time quantitative PCR determination of twogroups of cells in the miR-24content. The experiment was repeated3times.Using MTT colorimetric method to determine JEG-3choriocarcinoma cellproliferation activity. The test set4parallel complex holes. Flow cytometricdetection of JEG-3cell apoptosis, this experiment was also repeated3times.Results: At37centi-degree,5%(volume fraction) CO2,JEG-3choriocarcinoma cell culture in the fetal bovine serum on1640culturemediumb containing15%(volume fraction). The growth is in good condition.Cell membrane integrity is kept. Cell boundaries is clear, oval or round.Chromatin is uniform.TGF beta1100ng/ml for JEG-3choriocarcinoma cellsin logarithmic growth phase,RNA extraction after respectively24h,48h, usingquantitative PCR method for the determination of miRNA-24expression inexperimental group compared with the controlled group, it is significantlyreduced (P <0.05); TGF beta1100ng/ml for JEG-3choriocarcinoma cellsin logarithmic growth phase, after respectively24h,48h,Using MTT assay todetermine the cell proliferation rate, it is significantly elevated (P <0.05);TGF beta1100ng/ml for JEG-3choriocarcinoma cells in logarithmic growthphase, after respectively24h,48h,using flow cytometry to detect the apoptosisrate,it has no significant change (P>0.05).Conclusions:1.MiRNA-24express in JEG-3choriocarcinoma cells.2.TGF beta1can inhibit JEG-3choriocarcinoma cells miRNA-24expression.3.Down regulation of miRNA-24can promote JEG-3cell proliferation ofchoriocarcinoma.4.Down regulation of miRNA-24and JEG-3had nocorrelation with choriocarcinoma cell apoptosis. |
PDF Full Text Request