| The incidence of lung cancer has increasing year by year, the high mortality rateis a serious facing problem for each respiratory physician. All-trans retinoic acid(All-trans retinoic acid, ATRA) is A natural vitamin A metabolites and plays animportant regulatory role in both normal cells and tumor cell proliferation, growthand differentiation. Since ATRA have been used in the treatment of early acutemyelocytic leukemia,encouraging clinical results have been achieved. All-transretinoic acid inhibit the progress of tumor cell cycle on a wide variety of tumor cellcycle factors and the adjustment of the relevant proteins, as a result accelerate thedifferentiation of tumor cells, inhibit the proliferation of tumor cells,lead to theapoptosis of tumor cells[1]. The recent studies have confirmed that ATRA in a widevariety of tumor such as bladder cancer, prostate cancer, breast cancer, glioma,neuroblastoma and skin cancer treatment has achived great potential. Recentstudies have shown that all-trans retinoic acid can promote the proliferation of theU87glioma stem cells,increase the ratio of GFAP positive cells in the daughtercells,and obviously inhibit the cell proliferation[2]. Joint of platinum kinds of drugsand the third generation chemotherapy drugs, such as taxol, gemcitabine, stand forkang chemotherapy is the standard solution of non-small cell lung cancer.Theresearch reflects platinum drugs and other drug combination chemotherapy can significantly control symptoms, prolong the median survival and improve theirquality of life. There are many kinds of tumor therapy method,inducing tumor cellapoptosis is one of the important ways.The bcl-2family is one of the key genes whichare controlling the networking of apoptosis,and the bcl-2and bax belong to the familyof the bcl-2.The bcl-2gene in most cells restrain cell apoptosis,the function of bax ison the contrary,in contrast,promote cell apoptosis[3].Recent researches show thatATRA and cisplatin affect A549cells, ATRA can mainly impact G1phase and Sphase of cells,G1phase produce rRNA、mRNA、tRNA and ribosome,S phase is cellDNA synthesis stage,and G1phase and S phase proportion reduce,cause the A549cell cycle block,DNA synthesis obstacles, and inhibit the growth and metabolism andproliferation and result in cell apoptosis[4].But effects of all-trans retinoic acid andcisplation on nude mice transplantation tumor of lung cancer A549cells can rarelyreport,and all-trans retinoic acid and cisplation are how to affect bax and bcl-2genesof the lung cancer cell apoptosis genes,these are worth to explore and research.In thisexperiment ATRA and cisplatin affect nude mice transplantation tumor of lungcancer A549cells,explore its effects on lung cancer cell proliferation and apoptosis,while test the bcl-2and bax gene expression after different chemotherapy drugintervention for A549cell transplantation tumor, and thus provide the theory basisfor the lung cancer treatment of all-trans retinoic acid.Pupose：The objective of this research is to explore effects of all-trans retinoic acid andcisplation on nude mice transplantation tumor of lung cancer A549cells and itsregulatory mechanism by animal esoteric test.Metods：1．The cell culture: cultured lung cancer A549cells.2．This experiment established a human lung cancer A549cells transplantationtumor animal models, observe nude mice mental state, skin gloss, activity, diet,drinking water, and weighed. 3．Animals were grouped and dosed and this experiment let A549cells toinoculate to nude mice, nude mice for transplantation tumor were randomly dividedinto four groups, each group of six, which were randomly divided into control group,ATRA group, cisplatin group, the ATRA+cisplatin group, were fed medicines fortotal6times. The general situations were observed for nude mice.4．This experiment adopted the Hematoxylin-eosin Hematoxylin-eosin (HE)staining to observe nude mouse transplantation tumor tissue pathology changecharacteristics after chemical drug treatment.5． This experiment adopted immunohistochemical method to detect theexpressions of the Bcl-2protein and the expression of Bax protein after chemicaldrug treatment for nude mouse transplantation tumors.The ends of DNA nucleotidestransferase Mediated Nick End Labeling (TdT-Mediated dUTP-Biotin Nick EndLabeling, TUNEL) staining cbserved transplanted tumor cells apoptosis situations,cell nucleus ware dyed to tan, were observed with optical microscope.this experimentchosed10at high magnification vision,and had each view contain100cells,apoptosis index were obtained. Apoptosis index to count was apoptotic cells counts inthe percentage of1000tumor cells.Results：1．This experiment noticed solid tumor for irregular shape after inoculation for6to7days. Transplantation tumor tumor rate: nude mice were inoculated for16dayslater, a total of28nude mice were given subcutaneous injection for dorsal parts,there were24nude mice inoculated into tumor at a rate of85.7%.With the passage oftime, the control group in nude mice eating and activities decreased significantly,appeared rapid tumor growth; ATRA+cisplatin group appeared basic normal eatingand activity, tumor growth was slow; States of ATRA and cisplatin group nude miceand the tumor growth situation were between control group and combination group.2．Compared with control group, the volumes of transplanted tumors and theweights among ATRA group, cisplatin group and ATRA+cisplatin group decreasedobviously, among them the biggest drop was in ATRA+cisplatin group. Variance analysis and comparison showed that ATRA group, cisplatin group and combinationgroup of tumor growth was significantly slower than control group (P <0.05); Andthe anti-tumor rate of combination group was higher than ATRA group, cisplatingroup significantly (P <0.05)3．The transplanted tumor cell necrosises and apoptosises increased amongATRA group, cisplatin group and ATRA+cisplatin group. Cell necrosises andapoptosises ATRA+cisplatin group was obviously more than ATRA and cisplatingroup.4．Immunohistochemical detected nude mice transplanted tumor tissues whichwere affected with all-trans retinoic acid and cisplatin,prmoted bax gene expression,inhibited bcl-2gene expression. For the conclusion of correlation analysis of paireddata, the expressions between bcl-2gene and bax gene had the linkage, and werenegative correlation; The ends of DNA nucleotides transferase Mediated Nick EndLabeling staining observed transplanted tumor cells apoptosis situations, throughdirect correlation analysis, Bax index and apoptosis was positively related(thecorrelation coefficient was r=0.578, p=0.000); bcl-2was negatively correlated withthe apoptosis index(the correlation coefficient r=-0.772, p=0.000), bcl-2geneinhibited cell apoptosis, bax gene promoted cell apoptosis.Conclusion：1． all-trans retinoic acid and cisplatin inhibit the growth of nude micetransplantation tumor of lung cancer A549cells, promote the apoptosis of transplant-tation tumor cells, the combined effects are more obvious brtween them.2．all-trans retinoic acid and cisplatin for nude mice can inhibit tumor growth,may promote the expression of bax and inhibit the expression of bcl-2gene, bcl-2gene inhibits cell apoptosis, bax gene promots cell apoptosis. |
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