Alteration of the Cyclin D1／p16-pRB Pathway, Cellular Proliferation and Apoptosis in Glioma

Objective:To study the alteration of cyclin D1,p16 and pRB in glioma,analyze proliferation and apoptosis of tumor cells,and discuss the pathogenesis of glioma. Methods:Thirty-seven glioma specimens were classified as astrocytoma(25 cases,including 7 fibrillary cases;6 protoplasmic cases;12 anaplastic cases),and glioblastoma(12 cases,including 4 GBM cases).Ten normal brain tissues were taken as controls.The expression of cyclin D1,p16 and pRB were detected by immunohistochemical method.Cellular proliferation was assessed by Ki-67 label index(Ki-67 LI).Cellular apoptosis was detected by TUNEL and apoptotic indices(AI)was calculated. Results:The alterations of three proteins were cyclin D1 overexpression(28/37,75.7%),p16 and pRB deletion(20/37,54.1 % and 12/37,32.4%),which were closely related to tumor types,particularly in malignant glioma.Ki-67 LI and AI were higher when pRB pathway was abnormal.Apoptosis was minor in astrocytic tumors(astrocytomas,0.010±0.002;glioblastomas,0.057±0.016). Conclusion:The abnormalities of cyclin D1/p16-pRB pathway correlated closely with pathogenesis of glioma.

Expression of positive and negative regulators of cell cycle during wound healing

OBJECTIVE: To detect the expression of cell cycle positive regulators cyclin D(1), cyclin E, CDK(2), CDK(4) and negative regulators p21(cip1), p27(kip1), p16(ink4a) and p15(ink4b) during wound healing in rats. METHODS: Open wounds of full-thickness skin, diameter 1.8 cm, on rat backs were used as the wound model. Wound tissues were harvested on postwounding days 3, 5, 7, 9, 11, 14, 21 and 30. Ki67 expression in granulation tissue was detected by immunohistochemical assay. The patterns of the expression of cyclin D(1), cyclin E, CDK(2), CDK(4) and p21(cip1), p27(kip1), p16(ink4a), p15(ink4b) were detected by Western blot. RESULTS: Cell proliferation in granulation tissue took place predominantly within the first week after injury, with the proliferation peak occurring at postwounding day 5. There were no dramatic variations in the expression of cyclin D(1), CDK(2) and CDK(4) during wound healing. Up-regulated cyclin E was maintained from day 3 to 11 after injury, and then was down-regulated. No expression of p16(ink4a) and p15(ink4b) was found. p21(cip1) was expressed only from day 7 to 14, with peak expression observed on day 9. Constitutive p27(kip1) was expressed throughout wound healing with low levels in the proliferating period of day 3 to 5 and with increased levels in the post-mitotic and remodeling stage. The expression of p21(cip1) and p27(kip1) showed an inverse gradient to that of Ki67. CONCLUSION: p21(cip1) and p27(kip1) play a supervising role in preventing the hyperproliferative tendency in tissue repair.

Effect of Yanggan Jiedu Sanjie formula on human hepatocellular carcinoma Bel-7402 cells

OBJECTIVE: To observe the effect of Yanggan Jiedu Sanjie(YGJDSJ) formula on human hepatocellular carcinoma Bel-7402 cells.METHODS: Bel-7402 cells were treated with YGJDSJ. Cell proliferation was detected by cell counting kit-8 assay. Cell apoptosis was identified by Hoechst 33258 staining and flow cytometric analysis. Cell cycle distribution was quantified by flow cytometric analysis. Caspase activities were measured by commercial kit. Cell senescence was detected by senescence-associated β-galactosidase(SA-β-gal)staining. Protein expression and phosphorylation were identified by Western blot. Protein expression was knocked-down by siRNA.RESULTS: YGJDSJ inhibited proliferation of Bel-7402 cells in a dose-and time-dependent manner.YGJDSJ induced apoptosis and activated caspase-3, 8, and 9 in Bel-7402 cells. YGJDSJ-induced apoptosis was completely abrogated by a pan caspase inhibitor, Z-VAD-FMK. YGJDSJ also induced cell senescence, up-regulated cyclin-dependent kinase inhibitor 1 a(CDKN1 a) and CDKN2 a expression and down-regulated retinoblastoma protein(RB) phosphorylation in Bel-7402 cells. Specific knockdown of CDKN1 a and CDKN2 a significantly reduced YGJDSJ-induce cell senescence in Bel-7402 cells.CONCLUSION: YGJDSJ inhibited cell proliferation,induced caspase-dependent apoptosis and CDKN1 a/CDKN2 a-RB signalling mediated cell senescence in Bel-7402 cells. Our findings suggest that YGJDSJ might be potential for hepatocellular carcinoma treatment.

艾炷灸对D-半乳糖衰老小鼠大脑皮层细胞周期蛋白依赖性激酶抑制因子、视网膜母细胞瘤抑制蛋白及c-fos的影响

目的:探讨艾炷灸治疗D-半乳糖衰老小鼠的可能机制。方法:雄性昆明小鼠60只随机分为生理盐水组、造模组、艾灸1组、艾灸2组、尼莫地平组,每组12只。皮下注射D-半乳糖造成小鼠衰老模型。艾灸1、2组分别选取小鼠"足三里""悬钟""关元""百会"行艾柱灸治疗,尼莫地平组给予尼莫地平灌胃。采用免疫组化法观察各组小鼠细胞周期蛋白依赖性激酶抑制因子(P16)、视网膜母细胞瘤抑制蛋白(pRb)及c-fos的表达。结果:造模组小鼠大脑皮质P16蛋白表达的神经元密度较生理盐水组增高(P<0.01),艾灸1、2组及尼莫地平组较造模组降低(P<0.01)。造模组小鼠pRb、c-fos蛋白表达的神经元密度较生理盐水组、艾炷灸、尼莫地平组降低(P<0.01,P<0.05)。其余组各指标比较差异无统计学意义(P>0.05)。结论:艾炷灸"足三里""悬钟""关元""百会"可调控D-半乳糖衰老小鼠脑组织P16、pRb、c-fos蛋白的表达。