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.

Protective Effects of Overexpression of bcl-xl Gene on Local Cerebral Infarction in Transgenic Mice Undergoing Permanent Occlusion of Middle Cerebral Artery

In order to investigate the protective effects of the overexpression of bcl-xl gene on local cerebral infarction in the transgenic mice subject to permanent occlusion of middle cerebral artery, the models of bcl-xl transgenic mice were established and subjected to cerebral infarction by intraluminal occlusion of the middle cerebral artery. The infarct volume and the neurological scores were observed and comparison between the wild type mice and the transgenic mice was made. It was found that the infarct volume and the neurological scores in the transgenic mice were significantly decreased as compared with those in the wild type mice. It was suggested that the overexpression of bcl-xl gene in transgenic mice could reduce the infarct volume and improve the neurological function of the mice.

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.

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）.

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.

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.

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.

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)

Cationic Liposome-mediated bcl-xl Gene Transfection into Human Keratocytes

The efficiency and safe range of LipofectamineTM2000 (LF2000)/bcl-xl applied in human keratocytes, the optimal ratio of LF2000/bcl-xl and the bcl-xl gene expression in human keratocytes were investiaged. By using trypan-blue staining, the effects of LF2000 and bcl-xl on the survival rate of the cultured human keratocytes were measured respectively. By using semi-quantitative RT-PCR, the efficiency and the expression of LF2000-mediated bcl-xl transfection into keratocytes were examined. The results showed that the survival rate of human keratocytes had no signficant change in the presence of LF2000 (20 μg/ml) or bcl-xl (10 μg/ml) for 24 h. LF2000 could effectively mediate the transfection of exogenous gene bcl-x1 into human keratocytes. The best transfection efficiency could be obtained when the ratio of bcl-xl/LF2000 was 1:8. One day after transfection, the positive cells for bcl-x1 could be detectable, and the positive rate reached the peak on the post-transfection day 3 (48.3 %), then gradually decreased. Fifteen days after transfection, there were few positive cells. It was suggested that LF2000 could effectively transfer the exogenous gene bcl-xl into human keratocytes without obvious toxicity during a concentration range. LF2000/bcl-xl may be likely to play an important role in gene therapy of human keratocytes.

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.

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.

THE EXPRESSION OF BCL-2 GENE AFTER TRANSIENT FOCAL ISCHAEMIA AND THE EFFECT OF MK-801

in order to clarify the pesible role of the bcl-2 gene imolved in the cell death Program,and the relatiouship of glutamate receptors with bcl-2 gene expressin, this study examied the expression of bcl-2 gene protein, the neuronal status of apoptosis and the effects of MK-801 using immunohistochemistry and in situ terminal.labelling methods after 30 min of.middle cerebral artery(MCA) occlusion and followed by 24 h of reperfusion. The presence of bcl-2 gene protein increased in the ipeilateral hemisphere of ischaemis espeially in the MCA territory MK-801 enhanced the expresion of the bcl-2 gene protein. No DNA fragmentation was detected in this experiment. In conclusion. bcl-2 gene activity increased during transient focal ischaemia, and was potentiated by MK MK801, which may be an endogenous protective mechanism .against ischaemic apoptosis. Apoptosis wasnot detected after tranient focal ischoemia. for 30 min rollowed by 24 h of reperfusiou.

藏红花素通过跨膜受体蛋白/发状分裂相关增强子1信号通路对缺氧诱导的视网膜神经节细胞凋亡的影响

目的探讨藏红花素对缺氧诱导的视网膜神经节细胞凋亡的作用及其可能机制。方法于2021年1月至2022年1月采用不同浓度藏红花素处理视网膜神经节细胞RGC-5,四甲基噻唑蓝(MTT)法检测细胞存活情况并筛选合适浓度。培养RGC-5细胞并用氯化钴(CoCl_(2))处理建立缺氧模型,分为缺氧组、藏红花素组、阳性对照(抗坏血酸)组和藏红花素+跨膜受体蛋白信号通路抑制剂(DAPT)组,另设对照组。Cell counting kit-8法检测细胞存活情况;采用流式细胞术检测细胞凋亡率;钙荧光探针(Flou-4)实验检测各组细胞钙离子水平;实时定量PCR法检测跨膜受体蛋白(Notch1)、发状分裂相关增强子1(Hes-1)mRNA表达情况;蛋白质印迹法检测凋亡蛋白B细胞淋巴瘤因子2(Bcl-2)、Bcl-2相关蛋白(Bax)、钙依赖性蛋白酶家族1(Cal⁃pain1)蛋白表达情况。结果藏红花素组细胞活力0.83±0.08高于缺氧组0.45±0.04,细胞凋亡率(17.92±1.21)%低于缺氧组(51.82±5.36)%,钙离子水平0.27±0.04低于缺氧组0.76±0.05,差异有统计学意义(P<0.05);藏红花素+DAPT组细胞活力0.50±0.06低于藏红花素组0.83±0.08,细胞凋亡率(36.50±3.50)%高于藏红花素组(17.92±1.21)%,钙离子水平0.65±0.05高于藏红花素组0.27±0.04,差异有统计学意义(P<0.05)。与缺氧组比较,藏红花素组Bcl-2蛋白表达水平升高,Notch1、Hes-1mRNA表达、Bax和Calpain1蛋白表达水平降低(P<0.05)。与藏红花素组比较,藏红花素+DAPT组Bcl-2蛋白表达水平降低,Notch1、Hes-1mRNA表达、Bax和Calpain1蛋白表达水平升高(P<0.05)。结论藏红花素对体外培养的缺氧RGC-5细胞凋亡有一定的抑制作用,可能是通过抑制钙离子内流,阻滞Notch1/Hes-1通路,提高细胞内抑凋亡蛋白Bcl-2表达水平发挥作用。

BCL、RIP细胞凋亡基因向小麦中的导入和赤霉病抗性鉴定

利用农杆菌介导法将BCL和RIP 2个与细胞凋亡有关的基因分别导人了小麦品种扬麦10号和Bobwhite，转化效率分别为1．60％和1．25％。Southern检测结果表明，细胞凋亡基因已稳定整合到小麦染色体上，多数植株为单拷贝整合。Northern检测结果表明，细胞凋亡基因能够在小麦遗传背景中高水平转录为RNA。转基因植株T1代分离比例为2．11～2．33：1，表明外源基因在后代中能够稳定遗传。BCL转基因植株和RIP转基因植株对赤霉病均表现出一定抗性，其中BCL-20、BCL-21、RIP-8、RIP-18等15个T1代植株的小穗发病率为5．6％～16．1％，可望进一步培育抗赤霉病小麦新材料。

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。

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.

Bax-Bcl-2异源二聚体与胃癌细胞凋亡的关系

目的：明确Bax-Bcl-2异源二聚体与NSAIDs诱导胃癌细胞凋亡的关系。方法：以NSAIDs诱导胃癌细胞凋亡,并通过丫啶橙(AO)染色、共聚焦显微镜、流式细胞术、TUNEL法加以证实。应用Western blot方法检测Bax、Bcl-2蛋白的表达,应用免疫沉淀-蛋白印迹法检测Bax-Bcl-2异源二聚体水平的改变。结果：NSAIDs药物吲哚美辛(indomethacin,indo)800 mmol/L和阿司匹林(aspirin,Asp)8 mmol/L作用24 h后,AGS细胞发生显著的凋亡(Indo 800 mmol/L作用24 h凋亡率(9．34±1．99)%,48 h(38．97±3．36)%,Asp 8 mmol/L 48 h凋亡率(17．60±3．30)%。随着药物作用时间的延长,Bax-Bcl-2异源二聚体水平逐渐增高,在6～48 h内均呈现增强趋势,Bax蛋白表达的增强在6～24 h最为明显,Bcl-2蛋白未检测到。结论：NSAIDs可诱导胃癌细胞AGS凋亡；Bax-Bcl-2异源二聚体可能具有促进细胞凋亡的作用,也可能是NSAIDs调控肿瘤细胞凋亡的一个重要作用点。

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。

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。