Inlfuence of FSH Treatment on Expression of CDC25A,TSSK3 and P53in Vitro Cultured Sertoli Cells of Calf

CDC25A, TSSK3 and P53 expressionsin vitro in cultured sertoli cells after FSH treatment were studied in order to provide some data for further researches of spermatogenesis. Different concentrations of...     

Effect of tetrandrine on radiosensitivity of nasopharyngeal carcinoma cells

AIM: To investigate the mechanism of the radiosensitizing effect of maximum non-cytotoxic doses of tetrandrine (Tet) on nasopharyngeal carcinoma cell lines CNE1 and CNE2.METHODS: The cells were treated with ma-ximum non-cytotoxic doses of Tet (for CNE1 cells at 1.5 μmol/L and for CNE2 cells at 1.8 μmol/L), irradiation at 4 Gy, or combination of irradiation and maximum non-cytotoxic doses of Tet. The cell cycle distribution was analyzed by flow cytometry. The protein levels of γ-H2AX, cleaved caspase-3, p-CDC25C, CDK1, p-CDK1, cyclin B1, ERK and p-ERK were determined by Western blot.RESULTS: The expression of γ-H2AX was increased in CNE1 cells and CNE2 cells after combined treatment with irradiation and maximum non-cytotoxic doses of Tet. The percentages of CNE1 cells and CNE2 cells at G₂/M phase in irradiation group were (18.09±0.42)% and (18.48±1.32)%, respectively, which were decreased to (15.88±1.04)% and (13.80±0.82)% in combined treatment group, respectively (P<0.05). Combined treatment enhanced the increase in the protein level of cleaved caspase-3 caused by irradiation. The protein levels of p-CDC25C and p-CDK1 were increased in a dose-dependent manner by Tet treatment (P<0.05), while the expression of CDK1 showed no difference among different doses of Tet treatments. The protein levels of p-CDC25C, p-CDK1 and CDK1 showed no difference after the treatment with maximum non-cytotoxic doses of Tet. The combined treatment with irradiation and the maximum non-cytotoxic doses of Tet decreased the protein levels of p-CDC25C and p-CDK1 (P<0.05), increased the expression of cyclin B1, and had no influence on the expression of CDK1 (P<0.05). The combined treatment resulted in an increase in the protein level of p-ERK1 (P<0.05).CONCLUSION: The maximum non-cytotoxic doses of Tet enhance the DNA damage and apoptosis in CNE1 cells and CNE2 cells caused by irradiation, and the mechanism might be associated with ending of G₂/M arrest via activation of ERK/CDC25C/CDK1/cyclin B1 pathways.     

Effects of RNA interference targeting CDC25agene on proliferation of human liver cancer HepG2 cells

AIM: To investigate the effect of silencing cell division cycle 25a (CDC25a) gene on the proliferation of human hepatoma HepG2 cells. METHODS: CDC25agene in human hepatoma HepG2 cells was silenced by RNA interference. Real-time PCR was applied to detect the expression of CDC25a, cyclin E and CDK2 at mRNA levels in the HepG2 cells. Western blotting was applied to detect the expression of CDC25a at protein level. In addition, MTT assay, Giemsa staining and flow cytometry were used to measure the proliferation of human hepatoma HepG2 cells. RESULTS: The expression of CDC25a at mRNA and protein levels in RNA silence group was lower than those in negative control group and normal control group (P＜0.05). The mRNA expression of cyclin E and CDK2 in silence group was lower than that in negative control group and normal control group (P＜0.05). The cell proliferation in silence group was lower than that in negative control group and normal control group (P＜0.05). The results of flow cytometry revealed that the cells in silence group were blocked in G1 phase. CONCLUSION: Infection of LV-CDC25a-RNAi recombinant to the HepG2 cells effectively inhibits the CDC25agene expression and the proliferation of human hepatoma cells, and arrests the cells in G1 phase, suggesting that CDC25agene may be a key target for the treatment of liver cancer.     

Calculation and Analysis on Critical Moment of Thin-walled Beams under Unequal End Moment

In this paper, comparing the bending-twisting model with the tension-bending one, the critical moment of the thin-walled beams under unequal end moment is derived easily by the improved CDC (column deflection curve) method based on the increment interaction equations of beam-columns.A simplified formula is presented and the calculated results show a good agreement with the numerical ones.     

CDC25B Involved in Proliferation of Sertoli Cells of New Born Calves Through FSH and Possibly Being Key Regulating Factor

The effects of FSH on the proliferation of sertoli cells of new born calves were studied in order to provide some data for theoretical research and practical use of spermatogenesis in vitro. Different concentrations of FSH(0, 0.01, 0.02, 0.04, and 0.08 IU · mL~(-1)) were taken to treat bovine sertoli cells in vitro culture, the number of sertoli cells and the expression of seven genes were determined at 6, 12 and 24 h after FSH treatments. FSH could significantly promote the proliferation of in vitro cultured sertoli cells. FSH had no significant effects on the expression of CDC25A and could significantly improve the expression of CDC25B. 0.04 IU · mL~(-1) and 0.08 IU · mL~(-1) FSH treatments decreased the expression of CDC25C at 12 h. 0.08 IU · mL~(-1) FSH treatment decreased the expression of CDC25C at 24 h. 0.04 IU · mL~(-1) FSH could significantly decrease the expression of GSK-3β and improve the expression of β-catenin at 6, 12 and 24 h. 0.02, 0.04 and 0.08 IU · mL~(-1) FSH treatments enhanced the expressions of CYCLIND1 and C-MYC. In conclusion, FSH promoted the proliferation of sertoli cells and 0.04 IU · mL~(-1) FSH concentration could significantly promote the proliferation of in vitro cultured sertoli cells. FSH promoted the proliferation of sertoli cells by CDC25B and WNT/β-catenin and CDC25B might be the key regulator to the proliferating rate of sertoli cells of bovine calf.     

鸡CDC25B-mRNA探针制备及其在鸡十二指肠黏膜的原位杂交反应

应用RT-PCR方法从鸡胚中扩增CDC25B基因片段，将其连接于pGM-Teasy。分别利用pGM-Teasy中T7和SP6启动子及其RNA聚合酶，以线性化的CDC25B/pGM-Teasy为模板转录合成正、反义DIG标记RNA探针。以合成的地高辛（DIG）标记的CDC25B-mRNA为探针，进一步应用原位杂交组织化学方法（in situhybridiza-tion histochemistry，ISHH）探查CDC25B-mRNA在鸡十二指肠黏膜的分布。结果表明，成年鸡十二指肠肠腺上皮细胞中有丰富的CDC25B-mRNA的转录，其中CDC25B-mRNA探针杂交阳性细胞在肠腺基底部和小肠绒毛中部分别占上皮细胞总数的81.60%&#177;9.63%和36.21%&#177;8.81%。原位杂交阳性产物大部分分布于十二指肠肠腺上皮“干细胞部”和“增生部”细胞的胞质和胞核，肠腺基底部杂交信号由下至上逐渐减弱，至小肠绒毛下部消失，转为阴性。在黏膜肌层以及肌肉层杂交反应呈阴性。本研究从基因水平证明了鸡十二指肠黏膜肠腺上皮“干细胞部”和“增生部”细胞中有CDC25B-mRNA的存在，表明该区域有活跃的增殖过程，以补充绒毛上端死亡脱落的细胞。     

Primary analysis on interaction between hCDC14A and BRAP2

AIM: To search for new candidate partners of human cell division cycle gene 14A (hCDC14A) and explore their functional relationships.METHODS: Yeast two-hybrid screening was employed to find hCDC14A new partners. Physical interaction between two proteins was verified using Pulldown and co-immunoprecipitation assays. Subcellular localizations were revealed by immunofluorescence. In vivo ubiquitination test implied their potential functional relationship.RESULTS: BRAP2 (BRCA1 associated protein 2) was found to be a new candidate partner of hCDC14A. hCDC14A was modified by ubiquitination, and BRAP2 increased this modification in vivo. As expected, hCDC14A and BRAP2 co-localized on mitotic spindles in HeLa cells.CONCLUSION: BRAP2 may be an ubiquitin E3 ligase of hCDC14A.     

Control of reproductive processes by growth hormone: extra- and intracellular mechanisms

Recent data on the association between growth hormone (GH) and male and female reproductive processes, as well as the effects of GH on these processes and on some reproductive and non-reproductive disorders, and possible extra- and intracellular mediators of its action are reviewed. The available data suggest that GH is an important endocrine and autocrine/paracrine regulator of reproduction. It controls proliferation, apoptosis, growth and differentiation and the secretory and generative activities of different reproductive organs. It also regulates their response to gonadotrophin-releasing hormone (GnRH) and gonadotropins. Despite the effects of GH on the IGF/IGFBP (insulin-like growth factor binding protein) system, oxytocin, steroids, activin, gonadotropin and gonadotropin receptors, the majority of GH's actions on the reproductive processes are probably mediated not by these substances but by specific GH receptors acting through cAMP/protein kinase A, protein kinase G, tyrosine kinase-, MAP kinase and CDC2 kinase-dependent intracellular mechanisms. Although GH treatments can increase the risk of some reproductive and non-reproductive disorders, they may be useful in improving gonadal function, inducing superovulation and in embryo production.     

大白猪MC4R、CDC16基因多态性及其与生长性状的关联分析

本研究旨在利用高分辨率熔解曲线(high resolution melt,HRM)分型方法检测大白猪黑素皮质素受体(melanocortin-4 receptor,MC4R)和细胞分裂周期蛋白16(cell division cycle 16,CDC16)基因的多态性,并对其与大白猪的生长性状进行关联性分析。试验共采集246头大白猪的耳组织样提取基因组DNA,对小群体样本进行PCR扩增后,通过测序方法寻找两个基因在该群体中的多态性位点,针对已发现的多态性位点设计HRM专用引物,利用HRM方法对大群体进行多态性检测,将所得结果与大白猪生长性状进行关联性分析。结果表明,在MC4R基因序列中检测到1个突变位点2207A>G,2个等位基因:A和G,3个基因型:AA、AG和GG;在CDC16基因第18外显子上检测到了1个突变位点837T>C,2个等位基因:T和C,2种基因型:TT和CT。χ~2适合性检验结果显示,2个基因的基因型频率和等位基因频率在2个种群中分布差异不显著,符合Hardy-Weinberg平衡定律(P>0.05)。多态信息含量(PIC)分析显示,MC4R基因在2个群体中均处于中度多态(0.25CDC16基因在2个群体中均处于低度多态(PIC<0.25)。关联分析结果发现,MC4R基因对大白猪体重及日增重具有显著影响(P<0.05),CDC16基因对大白猪体高、体长和体重等均具有显著影响(P<0.05)。综上所述,MC4R与CDC16基因对大白猪的生长发育具有一定的影响,为后续大白猪肉质性状与生长性状的现代分子选育提供参考。