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Objective To investigate the proliferation,apoptosis and cell cycle and possible mechanisms of different breast cell lines by difluoromethylorithine (DMFO).Methods The growth of breast cancer MDA-435 (ODC GG) cell lines and SK-br3 (ODC AA) cell lines treated with DFMO were observed.The apoptosis and cell cycle were detected by flow cytometry.PCR was applied to detect the changes of A and G alleles of ODC G316A in MCF-7 cells treated with DFMO.Results The growth inhibition rates of MDA-435 and SK-br3 cells treated with 10 mmol/L and 20 mmol/L DFMO after 48 h were 24.1％ and 33.6 ％,46.3 ％ and 53.5 ％,respectively,and there was statistical significance (t =2.134,P =0.021,t =2.213,P =0.019).The growth inhibition rates of MDA-435 and SK-br3 treated with 10 mmol/L and 20 mmol/L DFMO after 72 h were 28.9 ％ and 35.7 ％,54.3 ％ and 65.4 ％,respectively,and there was statistical significance (t =2.434,P =0.015,t =2.489,P =0.013).The apoptosis rates of MDA-435 (ODC GG) and SK-br3 (ODC AA) cells both dealt with 20 mmol/L of DFMO after 24 h,48 h and 72 h were (7.58± 2.06) ％ and (13.88±3.45) ％ (t =2.047,P =0.041),(43.28±14.28) ％ and (59.96±16.42) ％ (t =3.680,P =0.000),(77.87±30.25) ％ and (93.08±32.15) ％ (t =3.293,P =0.000 1),respectively.The proportions of S stage cells MDA-435 (ODC GG) and SK-br3 (ODC AA) cells under the same condition after 24 h,48 h and 72 h were (13.25±2.38) ％ and (12.89±2.21) ％ (P ＞ 0.05),(21.43±3.12) ％ and (12.24±3.55) ％ (t =2.638,P =0.012),(16.32±3.23) ％ and (15.24±3.01) ％ (P ＞ 0.05),respectively.After the treatment by DFMO,the expression of ODC G316A allele A in breast cancer cell line MCF-7 (ODC AG) was reduced (t =3.708,P =0.000),and the expression of G had no significant changes.Conclusion The proliferation inhibition and apoptosis in breast cancer cells treated by DFMO is different in breast cancer cells with different genetic type of ODC G316A.DFMO can inhibit the activity of ODC,and the mechanism may be that DFMO could selectively bind to ODC G316A allele A.
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Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells at different stages of maturation.MDSCs mediate the suppression of the anti-tumor immunity,and play a crucial role in cancer tolerance through suppressing the activity of T cells and natural killer cells,inducing T-regs and involving the angiogenesis,and then contribute to the tumor development and metastasis.Promoting the differentiation of MDSCs,reducing its quantity and inhibiting its function by using various methods may contribute to the recovery of patients normal immune status,the tumor progression control,and improvement of the efficacy of other anti-neoplastic therapies.Therefore,possible novel therapeutic approaches targeted at MDSCs could be considered and developed rapidly now.
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0.05). Conclusion:There is bigger difference process of tumor apoptosis between different cell types in the same topography site. Survivin may play adjuvant roles and Bcl-2 may play main roles in the inhibition of cell apoptosis in SCLC while the case is just reversed in NSCLC,it suggests that there were different apoptosis inducing factor and different apoptosis pathway due to different cell type in NSCLC and SCLC.
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Objective To promote the differentiation of Flk1+CD31-CD34-cells isolated from adult adipose tissues into pancreatic islet endocrine cells in vitro.Methods Flk1+CD31-CD34-cells were first cultured and plated in medium supplemented with B27,epidermal growth factor(EGF),and basic fibroblast growth factor(bFGF).Next,the culture medium was changed.The glucose concentration in the serum-free medium was increased.At the same time,betacellulin and nicotinamide were added.Reverse transcription polymerase chain reaction(RT-PCR) was used to detect the expression of nestin,ngn3,insulin promoter factor-1(IPF-1),insulin,and glucagon before and after differentiation induction;immunofluorescent staining for nestin,insulin and glucagon and radioimmunoassay(RIA) for insulin.Results Initially,a nestin positive precursor cell population was found,then small round cells increased in number after 6 days.Later on,they were differentiated into islet-like clusters.The induced cells resulted in the formation of clusters which exhibited higher insulin secretion and other pancreatic endocrine hormones.RT-PCR detected an enhanced expression of pancreatic genes in the differentiated cells.Immunofluorescence revealed a high percentage of insulin-expressing cells in the clusters.Furthermore,the intra-cellular insulin content was detected by RIA after the induction culture.Conclusion These cells represent a previously unidentified adult intrinsic pancreatic precursor population and are a promising candidate for cell-based therapeutic strategies.