老年女性乳癌组织中Bcl-2蛋白表达及临床意义

目的探讨B细胞淋巴瘤-2(Bcl-2)在老年女性乳癌组织中的表达及其与病人临床病理特征和预后的关系。方法采用免疫组织化学方法检测92例老年女性乳癌组织中Bcl-2蛋白的表达,分析Bcl-2蛋白在老年女性乳癌组织中表达与病人临床病理特征及预后的关系。结果Bcl-2蛋白在老年女性乳癌组织中的阳性表达率为80.4%。Bcl-2的表达与肿瘤大小、淋巴结转移、TNM分期、组织学分级和脉管瘤栓相关(χ^(2)=4.459~11.607,P<0.05)。分子特征分析结果显示,Bcl-2表达与病人的雌激素受体、人表皮生长因子受体-2表达和分子分型相关(χ^(2)=14.572~19.390,P<0.05)。生存分析显示,Bcl-2的表达与病人无进展生存率及总生存率无关(P>0.05)。结论检测Bcl-2蛋白的表达对于判断老年女性乳癌预后和指导治疗具有临床参考价值。

基于caspase-3/Bcl-2/Bax信号通路探究SMAC基因对肺腺癌细胞紫杉醇敏感度及细胞活性的影响

目的基于caspase-3/Bcl2/Bax信号通路探究SMAC基因对肺腺癌细胞紫杉醇敏感度及细胞活性的影响。方法建立肺腺癌紫杉醇耐药细胞株A549/Taxol,将细胞分为pcDNANC组(转染pcDNA-NC空白载体)、pcDNA-SMAC组(转染pcDNA-SMAC载体)、siRNA-NC组(转染siRNANC空病毒载体)和siRNA-SMAC组(转染siRNA-SMAC慢病毒载体)。qRT-PCR法检测细胞中SMAC mRNA表达;MTT法检测细胞敏感度;克隆实验法检测细胞增殖能力;Transwell法检测细胞侵袭能力;流式细胞术检测细胞凋亡能力;Western blot法检测细胞中caspase-3、Bcl-2和Bax蛋白表达。结果肺腺癌A549细胞较BEAS-2B正常细胞中SMAC mRNA表达明显降低(P<0.05)。pcDNA-SMAC组较pcDNA-NC组细胞中SMAC mRNA表达显著升高(P<0.05)。和siRNA-NC组相比,siRNA-SMAC组细胞中SMAC mRNA表达显著降低(P<0.05)。和pcDNA-NC组相比,pcDNA-SMAC组细胞IC_(50)、细胞克隆数、细胞侵袭能力及Bcl-2蛋白和Bcl-2/Bax比值均显著降低,细胞耐药指数逆转倍数为2.51倍,细胞凋亡能力及caspase-3和Bax蛋白表达明显高于pcDNA-NC组(P<0.05)。和siRNA-NC组相比,siRNA-SMAC组细胞IC_(50)、细胞克隆数、细胞侵袭能力及Bcl-2蛋白和Bcl-2/Bax比值均显著升高,细胞凋亡能力及caspase-3和Bax蛋白表达明显降低(P<0.05)。结论高表达SMAC可增加肺腺癌细胞的紫杉醇敏感度、抑制细胞增长和侵袭、促进细胞凋亡,且对caspase-3/Bcl-2/Bax信号通路有一定调控作用。

Transduction of Fas gene or Bcl-2 antisense RNA sensitizes cultured drug resistant gastric cancer cells to chemotherapeutic drugs

AIM To compare the expression level of Fas gene and Bcl-2 gene in gastric cancer cells SGC7901 and gastric cancer MDR (multidrug resistant) cells SGC7901/VCR, to transduce Fas cDNA and Bcl-2 antisense nucleic acid into SGC7901/VCR cells respectively, and to observe the expression of two genes in transfectants and non-transfectants as well as their drug sensitivity.METHODS Eukaryotic expression vector pBK-Fas cDNA and pDOR-anti Bcl-2 were constructed and transfected into SGC7901/VCR cells by lipofectamine, respectively. Northern blot and Western blot were used to detect the expression of mRNA and protein in SGC7901/VCR and SGC7901 cells and transfectants, and drug sensitivity of transfectants for VCR, CDDP and 5-FU was analyzed with MTT assay.RESULTS After gene transfection, 80 for Fas and 120 for antisense Bcl-2 drug-resistant clones were selected from 2×105 cells, transfection rate being 0.04% and 0.06%. Two clones of SGC7901 Fas/VCR cells and SGC7901 anti Bcl-2/VCR cells were randomly selected for further incubation. Hybridization results showed that the expression level of Fas mRNA and protein in SGC7901/VCR cells was much lower, but that of Bcl-2 mRNA and protein was higher than that in SGC7901 cells. The expression of Fas mRNA and protein in SGC7901 Fas/VCR cells was higher, and of Bcl-2 mRNA and protein was lower in SGC7901 anti Bcl-2/VCR cells than that in non-transfectants. MTT assay showed that transfectants were more sensitive to VCR, CDDP, 5-FU than non-transfectants.CONCLUSION Bcl-2 gene displayed high expression while Fas gene had low expression in drug resistant gastric cancer cells. Expression of Bcl-2 protein was effectively blocked in SGC7901 anti Bcl-2/VCR cells by gene transfection. In contrast, the expression of Fas mRNA and protein in SGC7901 Fas/VCR cells increased. Fas gene and Bcl-2 antisense nucleic acid transfection sensitized drug resistant gastric cancer cells to chemotherapeutic drugs. These results suggest cell apoptosis plays an important role in the mechanism of MDR, and enhancing apoptosis might reverse MDR.

Altered Oncogene Activity Contributes to Compensation for Antisense Suppression of Bcl-2 and Tumor Resistance

Antisense oligonucleotides (oligos) have targeted growth regulatory proteins in prostate cancer models. To identify compensatory alterations in the expression of non-targeted genes we evaluate mono- and bispecific oligos targeting and equally suppressing the expression of the apoptosis inhibitory protein bcl-2. Bcl-2 is chosen because oligos directed towards it have entered clinical trials to restore apoptosis in cancer patients. Treated LNCaP cells compensate for the diminished bcl-2 by suppressing caspase-3 (an apoptosis promoter) while enhancing expression of AKT-1 (another apoptosis inhibitor), androgen receptor (AR) and its (p300 and IL-6) coactivators. Additional proteins are enhanced including PD-1, its ligand PD-L1 (immune checkpoint blockade markers) and fas-ligand, which activate apoptosis through the signal transduction, along with suppressor protein p53, polymerase transcription mediator MED-12 and signal transducer STAT-3. These alterations in expression may contribute to a greatly enhanced expression of the proliferation marker KI-67. This suggests that therapeutic approaches to restore apoptosis through suppression of bcl-2 lead to an altered expression in non-targeted genes involving apoptosis, androgen sensitivity, transcriptional activity and immune responsiveness, leads to an increase in proliferation (and a more androgen driven aggressive phenotype). In this study we evaluate the expression of two oncogenes (v-myc and K-ras) and find a large and significant enhancement of v-myc activity, which is produced by oligos targeting bcl-2 at the 5’ position. For K-ras, although significant suppression is produced by the bispecific targeting bcl-2 at the 3’ position, the percent change is relatively small compared with other compensatory alterations we have measured, and much less than in v-myc. Therefore, for the two oncogenes being evaluated, only increased v-myc activity is probably large enough to contribute to increased tumor aggressiveness in compensation for bcl-2 suppression.

Detection of apoptotic cells and immunohistochemical study of bcl-2 and p53 gene protein in primary gastric mucosa-associated lymphoid tissue (MALT) lymphoma

To identify the apoptotic cells in gastric MALT lymphoma and its relationship between bcl-2 and p53 gene expression. Methods: TdT-mediated dUTP biotin Nick End labeling (TUNEL) and immuno-histochemistry ABC method were used to display apoptotic cells and the gene protein expression of bcl-2 and p53 independently. Results: Apoptotic indices (AI) in high-grade MALT lymphomas were significantly higher than in mixed-grade group and low-grade group (P<0.05). Bcl-2 was expressed in 83% of low-grade tumors, 61.6% of the median-grade tumors and 43.7% of high-grade tumors. An inverse correlation was observed between the expression of bcl-2 and apoptotic indices. Only 27 cases were p53 positive. The frequency of p53 positivity was significantly increased as the histologic grade advanced (P<0.05). There was also an inverse correlation between the expression of bcl-2 and p53. Conclusion: Apoptosis may be important in tumors development and transmission. p53 and bcl-2 were important regulatory genes of apoptosis and may be associated with transformation from low- grade to high-grade lymphomas.

Isolation and identification of proteins binding to the major breakpoint region(mbr) of bcl2 gene

Objective： We have previously found that mbr is a regulatory element of the bcl2 gene. The objective of this study is to isolate and identify the proteins binding to the 37 mbr in the 3 ＇ -end of the mbr. Methods： Streptavidin magnetic particles were ligated to concatameric oligonucleotides of 37 mbr and incubated with the nuclear extracts of Jurkat cells. The DNA-binding proteins were eluted and then resolved by SDS-PAGE. After silver staining, the protein bands were excised and subjected to MALDI-TOF MS. Results： Several protein bands were detected after the isolation with magnetic particles, and Splicing factor, proline- and glutamine-rich（SFPQ）, Poly（ADP-ribose） polymerase I（PARP）, and promyelocytic leukemia protein（PML） were identified by MALDI-TOF MS. Conclusion： Several proteins were isolated and identified from the 37 mbr-protein complex. Results of this study establish a foundation for further study of the mechanisms by which mbr executes its regulatory function.

Effects of Bcl-2 Gene Interference on the Apoptosis,Proliferation and Progesterone Secretion of Goose Follicular Granulosa Cells

Based on published sequences for chicken Bcl-2,three siRNAs（small interfering RNA）were designed,and expression vectors were constructed and transfected into goose granulosa cells cultured in vitro.Bcl-2 protein,apoptosis and proliferation of granulosa cells,48 h after the transf ection,were analyzed by flow cytometry,and progesterone（P）secreted into the culture medium was measured by radioimmunoassay.In addition,apoptosis and Bcl-2 protein level were assessed in untreated granulosa cells from the four largest preovulatory follicles（F1F4）,the smallest preovulatory follicles（SPF）,small yellow follicles（SYF）and atretic follicles.The highest level of Bcl-2 protein was observed in granulosa cells from SPF,and levels in cells from healthy follicles were significantly higher than those of atretic follicles（P【0.05）.Bcl-2 protein levels in cells subjected to RNAi were significantly lower than those of controls（P【0.05）,while apoptosis indices（AI）,proliferation indices（PI）and P secretion in the RNAi treatments were higher than those of controls（P【0.05）.

Study on the Regulation of Bcl-2 Gene on Rat Spermatogenic Cells Apoptosis in Transcription Level

Objective To detect the change of Bcl 2 gene expression in the apopototic process of spermatogenic cells in rat with vasoligation and vasostomy, and to find out the relationship between the transcription of Bcl 2 and the apoptosis of spermatognic cells Materials & Methods Sixty adult male Sprague Dawley rats in 3 groups were operated with vasoligation and vasostomy. Then hybridization in situ with hypersensitive Bcl 2 RNA probe was used to detect the change of Bcl 2 mRNA. Results The transcription of Bcl 2 gene in spermatogenic cells was obviously inhibited in the vasoligation group compared with that in the control group (P<0.05), and the transcription in the vasostomy group showed no difference from that of the control group. Conclusion Bcl 2 gene has an anti apoptotic effect in rats with vasostomy, and there was a transcriptional regulation of Bcl 2 gene in rat spermatogenic cell during the period of pre vasoligation to post vasoligation and to post vasosotomy.

Bcl-2 GENE REARRANGEMENT DETERMINED BY PCR AS AMEAN TO DETECT MINIMAL RESIDUAL DISEASE INMALIGNANT LYMPHOMAS

Objective: To develop a sensitive method to detect minimal residual disease and to elucidate the significance of bcl-2 gene rearrangement in diagnosis and treatment of malignant lymphoma. Methods: Using polymerase chain reaction (PCR) to detect bcl-2 gene rearrangement and using serial dilution method to define the sensitivity of PCR. Results: In 9 different malignant lymphoma cell lines, Su-DHL-4 and Su-DHL-6 were shown bcl-2(MBR)/JH rearrangement, the sensitivity of PCR was 1:105. In 16 patients with follicular lymphoma, the peripheral blood and bone marrow were PCR positive in 4 cases both at initial diagnosis and after complete remission. Conclusion: Detection of bcl-2 gene rearrangement by PCR provides a sensitive and specific assay of minimal residual disease. It is helpful to improve staging of disease, prognosis and evaluation of the treatment results.

Silencing of Bcl-2 gene expression by siRNA transfection in- hibits the protective effect of fluvastatin against cell apoptosis in human aortic endothelial cells

Objective To study the protective effect of fluvastatin,one of the HMG-CoA reductase inhibitors (statins),against oxygen radical-induced oxidative damages in human aortic endothelial cell,and the role of Bcl-2 in this protection.Methods Human aortic endothelial cells with or without Bcl-2 siRNA transfection were subjected to 1-100 nM of fluvastatin and 100 la hydrogen peroxide for 24 hours.Bcl-2 mRNA and protein expression were measured by Taqman quantitative PCR and Western blotting.Cell apoptosis was measured by normal and fluorescent microscopy and Cell Death Detection ELISA.Results In the Bcl-2-expressed cells,fluvastatin significantly reversed hydrogen peroxide-induced microscopic apoptosis and apoptotic DNA fragmentation,which were accompanied by a markedly upregulation of Bcl-2 expression by fluvastatin.However,the endothelial protection by fluvastatin was completely lost in Bcl-2 siRNA transfected cells.Conclusion Fluvastatin protects human endothelial cells against oxygen radical-induced cell apoptosis in vitro,and this protection seemed to be mediated in a Bcl-2 dependent pathway.(J Geriatr Cardil 12008;5:33-38)

DETECTION OF BCL-2 GENE MAJOR BREAKPOINT REGION REARRANGEMENT IN HUMAN B-CELL LYMPHOMAS

Objective To investigate the frequency of t(14; 18) in different subtypes of B-cell lymphomas and the ability or the polymerase chain reaction(PCR) to detect this rearrangement in frozen samples. Methods 1o7 cases of B-cell lymphomas were studied uslng DNA extracted from rresh-frozen tissues. The DNA samples were amplified by PCR for bcl-2 MBR/JH. The products of bcl-2/JH rearrangement were hybridized with an internal olignucleotide probe or bcl-2 MBR. Results The rearranged bcl-2MBR/JH gene was detected in 13 of the 25(52. o% ) follicular center lymphomas, according to REAL classification: 8 of 11 (72. 7%) grade 1, 2 of 5(40. 0%) grade I, and 3 of 90 (33. 3%) grade, 17 of 82(2o. 8%) cases or difruse large B-cell lymphomas were found to have detectable bel-2 MBR/J. rearrangement- Conclusion The rrequency or bcl-2 MBR/JH rearrangement in diffuse large B-cell lymphomas is significantly lower than those in follicular center lympkomas(X2= 9. 28, P <o. oo5), suggesting that bcl2/JH rearrangements occur mainly in follicular center lymphomas. in addition, the result of reconstruction experiments suggest that amplification or bcl-2 MBR/JH rearrangements by PCR is both sensitive and specific for detection of t (14; 18 ) translocation.

盐酸右美托咪定预处理对缺血-再灌注损伤大鼠心肌Bax和Bcl-2表达的影响

目的研究盐酸右美托咪定对大鼠心肌缺血-再灌注损伤时心肌凋亡相关基因Bax和Bcl-2表达的影响。方法将21只健康SD大鼠随机分为3组:假手术组(sham组,n=7)、缺血-再灌注组(I/R组,n=7)、缺血-再灌注+盐酸右美托咪定组(DEX组,n=7)。采用结扎左冠状动脉前降支的方法制备在体大鼠心肌缺血-再灌注损伤模型。采用RT-PCR、免疫组化方法检测Bcl-2和Bax mRNA、蛋白的表达,TUNEL法检测凋亡细胞TTC染色测定心肌梗死面积。结果与sham组比较,I/R组Bcl-2和Bax mRNA和蛋白表达增加(P<0.05);与I/R组比较,DEX组Bcl-2mRNA和蛋白表达升高(P<0.05),Bax mRNA和蛋白表达下降(P<0.05),凋亡细胞明显减少(P<0.01),心肌梗死面积减小(P<0.05)。结论盐酸右美托咪定预处理可上调心肌缺血-再灌注损伤大鼠心肌Bcl-2mRNA和蛋白表达,下调Bax mRNA和蛋白表达,表明盐酸右美托咪定在心肌缺血-再灌注损伤中有抗凋亡的作用。

大鼠颈部淋巴引流阻断后海马bcl-2、bax表达和细胞凋亡的动态变化

为了研究淋巴滞留性脑病中海马bcl-2、bax基因表达和细胞凋亡的动态变化,本实验用阻断大鼠颈部淋巴引流的方法制备淋巴滞留性脑病模型,术后1、2、3、5、7和14d处死动物,H&E染色观察海马组织结构变化,TUNEL荧光标记检测原位细胞凋亡,RT-PCR检测海马bcl-2和bax的mRNA表达。结果显示脑组织有水肿的结构变化,第5天最明显。海马TUNEL阳性细胞数从术后2d开始增多,5d达最高值。bax表达于术后1d开始增高,第2天即达最高值。bcl-2表达于术后1d开始降低,5d达最低值。第14天上述指标均恢复到对照组水平。研究表明,阻断颈部淋巴引流所导致的淋巴滞留性脑病中海马bcl-2和bax的表达发生变化,而且海马神经细胞的死亡以凋亡为主。

川芎嗪对缺血/再灌注损伤大鼠肾脏细胞凋亡及Bcl-2和Bax表达的影响

目的:观察川芎嗪对急性缺血/再灌注(I/R)损伤大鼠肾脏细胞凋亡及凋亡相关蛋白的影响,探讨川芎嗪对急性肾I/R损伤保护作用的可能机制.方法:将40只Wistar大鼠夹闭双侧肾动脉45min再灌注24h,制备成急性肾I/R损伤动物模型,随机分为假手术对照组、I/R组、川芎嗪治疗组和川芎嗪预防组,采用原位末端标记法检测细胞凋亡指数,免疫组化法测定Bcl-2,Bax表达,电镜观察肾组织细胞超微结构.结果:I/R组较假手术对照组肾小管细胞凋亡指数明显增多(28.8±4.6vs1.9±0.5,P<0.01),Bax表达显著增强(162.6±17.1vs182.7±12.8,P<0.01),Bcl-2/Bax显著降低(1.1±0.1vs1.0±0.1,P<0.01);川芎嗪预防组较I/R组肾小管凋亡细胞数明显减少(13.6±2.9vs28.8±4.6,P<0.05),Bax表达明显减弱(179.1±12.7vs162.6±17.1,P<0.05),Bcl-2表达明显增强(166.6±15.1vs178.7±13.0,P<0.05),Bcl-2/Bax显著增高(0.9±0.1vs1.1±0.1,P<0.05).结论:川芎嗪对急性肾I/R损伤具有保护作用,其作用机制可能是通过调节凋亡相关基因Bcl-2和Bax介导的I/R损伤肾脏细胞凋亡而实现.

大鼠实验性肾缺血/再灌注引起肾小管上皮细胞凋亡及其与Bcl-2,Fas/FasL表达变化的关系

目的 :探讨大鼠实验性肾缺血再灌注引起肾脏损伤、肾小管上皮细胞凋亡情况及其与Bcl 2 ,Fas/FasL表达变化的关系 .方法 :建立大鼠肾缺血再灌注损伤模型 ,在不同时间点处死动物取肾组织石蜡包埋切片 ,HE染色分析肾组织病理损伤程度 ,用TUNEL法标记检测肾小管上皮细胞凋亡的变化 ,SABC免疫组化方法检测Bcl 2 ,Fas与FasL蛋白表达的变化 .结果 :缺血再灌注后肾组织的病理损伤主要发生在肾小管 ,肾小管上皮细胞凋亡指数增加 ,且随缺血再灌注时间延长而进一步上升 ,4 8h达高峰 (P <0 0 5 ) .Bcl 2蛋白在对照组呈弱阳性表达 ,缺血 3 0min ,60min后再灌注 0h有少量表达 ,再灌注 2 4 ,4 8及 72h呈阳性表达 ,4 8h达高峰 (P <0 0 5 ) ,并以远曲小管为主 .Fas,FasL蛋白在对照组呈阴性表达 ,缺血 3 0 ,60min后再灌注 0h有少量表达 ,再灌注 2 4 ,4 8及 72h呈阳性表达 ,以 72h时达高峰 (P <0 0 5 ) ,多表达在远曲小管 .HE染色可见肾缺血再灌注后各组均有不同程度的肾小管上皮组织片状坏死灶 ,以近曲小管为主 ,坏死灶周围有炎性细胞浸润 .结论 :肾缺血再灌注可诱导肾小管上皮细胞凋亡 ,Bcl 2 。

米非司酮对人早孕期蜕膜细胞凋亡及其调控基因bcl-2/bax的影响

目的 :探讨米非司酮对早孕期蜕膜组织细胞bcl 2 /bax的影响及与妊娠终止的关系。方法 :用琼脂糖凝胶电泳、TUNEL法检测凋亡的发生及凋亡细胞的定位 ,用免疫组化法检测bcl 2 /bax蛋白的表达和相互关系。结果 :(1)正常早孕 4 0 + 天蜕膜组织细胞大量凋亡 ,bcl 2蛋白表达量较低 ,bax蛋白有较强表达 ;(2 )正常早孕 5 0 + 天 ,凋亡细胞明显减少 ,bcl 2的表达显著增强 ,bax蛋白表达减弱 ;(3)早孕 5 0 + 天应用米非司酮 ,蜕膜组织出现大量凋亡细胞及明显凋亡带 ,bcl 2蛋白表达明显降低 ,bax蛋白表达较前明显增强。结论 :早孕期米非司酮流产的机制可能与蜕膜组织细胞凋亡异常相关 ,bcl 2 /bax途径可能是其诱导早孕期蜕膜细胞凋亡的重要因素。

NF-κB、bcl-2、bax在胃不典型增生、胃癌中的表达及其意义

目的:探讨核因子κB(nuclear factor kappa B,NFκ-B)、bcl-2及bax在胃不典型增生及胃癌中的表达及在胃癌发生中的作用。方法:采用免疫组化Power Vision两步法检测84例胃癌和54例胃不典型增生组织中NFκ-B、bcl-2及bax的表达,TNNEL法染色检测凋亡指标的改变。结果:NFκ-B、bcl-2、bax在84例胃癌组织中的阳性表达率分别为59.52%、52.38%、16.67%,在33例胃轻度不典型增生组织中阳性表达率分别为24.24%、21.21%、33.33%,三者在胃癌与轻度不典型增生组之间差异有统计学意义(P<0.05)。NFκ-B、bcl-2表达与肿瘤的大小相关(P<0.05),NFκ-B与bcl-2之间呈正相关(P<0.05)。在轻度不典型增生、重度不典型增生与胃癌组织中AI分别为(1.29±0.50)%、(0.96±0.36)%、(0.70±0.43)%,轻度不典型增生与重度不典型增生、胃癌之间差异均有统计学意义(P<0.05)。结论:在胃癌中NFκ-B可通过上调bcl-2的表达、改变bcl-2与bax的比值而抑制肿瘤细胞凋亡,进而影响肿瘤的生长、浸润、转移。

PTEN基因诱导人脑胶质瘤SHG-44细胞凋亡及bcl-2蛋白表达下调

目的 探讨PTEN基因对人脑胶质瘤SHG 44细胞凋亡及凋亡相关基因bcl 2表达的影响 ,阐明PTEN基因抑制肿瘤细胞增殖的机理。方法 PTEN基因体外转染SHG 44细胞 ,筛选阳性细胞克隆 ,以原位杂交、免疫组化方法检测PTEN基因的表达情况采用透射电镜、流式细胞仪和核DNA琼脂糖凝胶电泳检测细胞的凋亡情况以免疫荧光法检测bcl 2基因的表达。结果 PTEN基因转染的SHG 44细胞有PTEN基因和蛋白的表达。透射电镜下可见转染PTEN基因后细胞核染色质浓缩边集、胞浆浓缩、核碎裂及凋亡小体形成等典型的凋亡表现 ;流式细胞仪示细胞周期从G1 期到S期发生抑制 ,并且在G1 期峰前出现一明显的凋亡峰 (1 2 .9% ) ;细胞核DNA琼脂糖凝胶电泳呈现凋亡细胞特有的梯状条带 ;bcl 2的表达也显著下调。转染空载体和未转染的SHG 44细胞无明显的凋亡表现。结论 PTEN基因可诱导SHG 44细胞凋亡 ,并下调bcl 2蛋白的表达 。

迷迭香精油诱导肝癌HepG2细胞凋亡后bcl-2和bax基因表达变化的研究

目的:探讨凋亡相关基因bcl-2和bax在迷迭香精油诱导肝癌HepG2细胞凋亡后表达的变化。方法:水蒸气蒸馏法提取迷迭备精油,GC-MS鉴定其成分。采用免疫组化法检测bcl-2蛋白和bax蛋白表达。结果:不同浓度的迷迭香精油处理细胞12、24、48 h后bcl-2蛋白的表达降低,bax蛋白的表达升高,与对照组比较均有显著性差异,并且均现时间和剂量依赖性。结论:迷迭香精油诱导肝癌HepG2细胞凋亡与凋亡调控基因bax表达增强,bcl-2表达减少有关。

L-精氨酸对肺缺血/再灌注损伤时bcl-2、bax基因表达的影响

目的:探讨L-精氨酸对肺缺血-再灌注损伤(PIR I)时bcl-2、bax基因表达的影响。方法:采用在体兔单肺原位缺血-再灌注模型。实验兔36只,随机分为假手术对照组(sham,12只)、肺缺血-再灌注组(I/R,12只)和肺缺血-再灌注加L-精氨酸组(L-Arg,12只)。分别于再灌注5 h取左肺组织,观察bcl-2、baxmRNA定位表达、凋亡指数(AI)、肺组织湿干重比(W/D)、肺损伤组织学定量评价指标(IQA)及光镜、电镜下的组织形态学改变。结果:在肺小动脉内(外)膜、肺小静脉内膜、肺泡上皮及细支气管上皮,L-Arg组bcl-2 mRNA的表达及bcl-2/baxmRNA的比值显著高于I/R组(均P<0.01),baxmRNA的表达明显低于I/R组(P<0.01);AI、W/D和IQA值显著低于I/R组(P<0.01和P<0.05);肺组织形态学异常改变不同程度减轻。结论:L-精氨酸可上调肺组织bcl-2 mRNA的表达、下调肺组织baxmRNA的表达、调控bcl-2/baxmRNA之间的平衡而减轻细胞凋亡,对PIR I发挥积极的防治作用。