Protein tyrosine kinase Lyn mediates apoptosis induced by topoisomerase II inhibitors in DT40 cells.

Several sets of non-receptor protein tyrosine kinases (PTK) play important roles in apoptosis induced by various extracellular stresses. Anti-cancer drugs induce cellular DNA damage and cytotoxic events, leading to apoptotic cell death. We utilized the established chicken B cell line, DT40 cells and their derived mutants, lacking the respective PTK [DT40/Syk(-), DT40/Lyn(-) and DT40/Btk(-)], to examine a role of these PTK in apoptotic processes induced by anti-cancer drugs. All anti-cancer drugs examined induced apoptosis of wild-type DT40 cells. Interestingly,DT40/Lyn(-), but not DT40/Syk(-) and DT40/Btk(-) cells, become resistant to apoptosis induced by adriamycin and etoposide, topoisomerase II (Topo II) inhibitory agents, compared to wild-type DT40 cells, as assessed by DNA fragmentation and TUNEL analyses. Ectopic expression of Fyn, another Src family member, in DT40/Lyn(-) cells restores largely the susceptibility of the cells against Topo II inhibitor-induced apoptosis. Furthermore, it was found that Topo II inhibitors activate c-Jun N-terminal kinase (JNK) slightly in both wild-type and DT40/Lyn(-) cells to similar extents. Collectively, these results suggest that Lyn is involved in Topo II inhibitor-induced apoptotic signaling in DT40 cells independent of JNK.     

TRAIL联合紫杉醇诱导胃腺癌SGC-7901细胞凋亡作用研究

目的:观察紫杉醇联合肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导人胃腺癌SGC-7901细胞凋亡的作用及其协同作用机制。方法:将TRAIL、紫杉醇及TRAIL联合紫杉醇诱导SGC-7901细胞48小时,用流式细胞仪(FCM)检测细胞凋亡率和线粒体跨膜电位的改变;用MTT法检测SGC-7901细胞增殖反应;用免疫印迹(Westernblot)法检测TRAIL死亡受体DR4(TRAIL-R1)、DR5(TRAIL-R2)的表达变化。结果:TRAIL和/或紫杉醇对SGC-7901细胞增殖有抑制作用,两者联合用药组对细胞增殖的抑制率较单独用药明显增加(P<0.01);联合用药组细胞凋亡率较单独用药组明显增加(P<0.01);0.3μmol/L紫杉醇作用48小时后,DR4表达明显升高(P<0.05),而DR5表达没有明显改变(P>0.05)。结论:紫杉醇可协同TRAIL诱导SGC-7901细胞凋亡,DR4表达增加可能是其协同作用的机制。     

Resistance to Cytotoxic Chemotherapy Is Induced by NK Cells in Non-Hodgkin's Lymphoma Cells

It is known that B lymphoma cells are sensitive to cytotoxic chemotherapy, but primary or secondary chemoresistance frequently occurs and is the major cause of death in these patients. However, the mechanisms by which lymphoma cells acquire resistance to cytotoxic drugs are not fully understood. Recently, it was reported that B cells secrete immunoglobulin and produce cytokines after interacting with NK cells, thus indicating the importance of NK/B interactions. In this study, we investigated the mechanism of resistance to cytotoxic chemotherapy induced in cocultures of NK cells and Raji cells. Normally, Raji cells are doxorubicin-sensitive, but Raji cells cocultured with NK cells become doxorubicin-resistant. In addition, we detected the upregulation of CD69 and CD70 on Raji cells cocultured with NK cells, suggesting that Raji cells are activated by NK cells. We also found that the resistance of Raji cells to doxorubicin increased when they had been treated with NK cell coculture supernatant. Furthermore, boiled culture supernatant did not inhibit doxorubicin-mediated cell death, indicating that soluble factors are involved. Finally, we confirmed that NK cells produce TNF alpha, and that doxorubicin-sensitive Raji cells become doxorubicin-resistant after TNF alpha treatment. Taken together, these results suggest that B lymphoma cell resistance to doxorubicin-mediated cell death is induced by coculture with NK cells, because of TNF alpha secretion.     

The effect of cyclophosphamide on Fas-mediated apoptosis.

Fas is a cell surface protein that can mediate apoptosis and belongs to the tumor necrosis factor (TNF) receptor family. Anti-Fas antibody induces apoptotic cell death in sensitive cells. Because many chemotherapeutic drugs are capable of initiating pathways leading to apoptosis, we determined the effect of cyclophosphamide, one of the most widely used anticancer drugs, on Fas mediated apoptosis in human lymphoma cell lines; SKW6.4 and Jurkat. Cell lines were cultured for 3 days alone in a medium or with cyclophosphamide (2 micrograms/ml). Anti-Fas IgM of various concentrations was added after treatment. Apoptosis was measured by electrophoresis of DNA fragmentation and surface expression of Fas was measured by flow cytometry. These cell lines were found to express Fas and were very sensitive to anti-Fas induced by cyclophosphamide in Jurkat except SKW6.4. Cyclophosphamide augumented apoptosis mediated by anti-Fas, synergistically. These results suggested that the anti-cancer drug might be mediated via the pathway of Fas mediated apoptosis in the lymphoma cell lines.     

RAD001通过诱导自噬提高人子宫内膜癌细胞对紫杉醇的敏感性

 目的：探讨哺乳动物雷帕霉素靶蛋白(mTOR)抑制剂RAD001通过诱导细胞自噬增强紫杉醇杀伤子宫内膜癌细胞作用的机制。方法：用MTT法检测RAD001对人子宫内膜癌Ishikawa和HEC-1A细胞的生长抑制作用,用激光共聚焦显微镜观察GFP-LC3蛋白的聚集;用流式细胞术检测细胞死亡;用Western blotting方法检测LC3-I、LC3-II、mTOR及ULK1蛋白的表达;用靶向ULK1的siRNA特异性地抑制Ishikawa细胞中ULK1的表达,再检测相关指标。结果：RAD001可抑制Ishikawa和HEC-1A细胞的增殖,提高它们对紫杉醇的敏感性。RAD001诱导Ishikawa和HEC-1A细胞发生自噬及自噬性细胞死亡。RAD001通过抑制mTOR/p70S6K通路、上调ULK1诱导自噬,从而产生紫杉醇增敏作用。结论：RAD001可以通过抑制mTOR信号通路,上调ULK1的表达,诱导自噬性细胞死亡的发生,从而提高子宫内膜癌细胞对紫杉醇的敏感性。     

Role of p53 in cellular response to anticancer nucleoside analog-induced DNA damage

Anticancer nucleoside analogs (e.g., ara-C, gemcitabine, fludarabine) induce apoptosis by incorporation into DNA. Removal of incorporated analogs from DNA by 3'-5' exonucleases is presumably a mechanism of drug resistance. Based on our previous observation that the 3'-5' exonuclease activity of wild-type (wt) p53 protein is able to preferentially remove mismatched nucleotides from DNA, in the present study we further investigated the ability of p53 to recognize and remove incorporated therapeutic analogs from DNA and its role in analog-induced apoptosis. We demonstrated that although the 3'-5' exonuclease of wt p53 protein was able to bind and excise the nucleoside analog residues from DNA in vitro, removal of the drug molecules from cellular DNA was slow in whole cells with wt p53 cells, and not detectable in mutant p53 cells. Furthermore, the wt p53 were more sensitive to the cytotoxic effect of the drugs compared to the p53-null or mutant cells. Incubation of ML-1 cells (wt p53) with gemcitabine caused an accumulation of p53 protein in their nuclei and preferentially induced apoptosis in the p53-positive cells, whereas the p53-negative cells remained intact. Transfection of p53-null cells with wt p53 expression vector enhanced the sensitivity of the cells to gemcitabine. Gel mobility shift assay using synthetic DNA containing gemcitabine as the probe suggests that p53 protein is likely to participate in the binding of the analog-containing DNA. Our study suggests that recognition of the incorporated nucleoside analogs in DNA by wt p53 did not confer resistance to the drugs, but it facilitated the apoptotic cell death process.     

Apoptosis of Hodgkin–Reed–Sternberg cells in classical Hodgkin lymphoma revisited

Benharroch D, Einav I, Feldman A, Levy A, Ariad S, Gopas J. Apoptosis of Hodgkin–Reed–Sternberg cells in classical Hodgkin lymphoma revisited. APMIS 2010; 118: 339–45. We scrutinized the role of apoptosis of the Hodgkin–Reed–Sternberg (HRS) cells in classical Hodgkin lymphoma (cHL) and critically reviewed its features in the light of conflicting evidence. In this study, we found that tumor cells in this neoplasm showed inhibition of apoptosis in 55% of the 217 cHL cases only. It is also suggested that the two factors considered responsible for apoptosis inhibition in HRS cells, nuclear factor‐κB and the latent membrane protein‐1 of the Epstein–Barr virus, do not correlate with apoptosis inhibition, in contrast with the findings in the consensual pathogenetic scheme. The most significant association of HRS cell apoptosis was with p53, the negative expression of which related with a high apoptotic index (p = 0.001). These findings support our contention that the role of apoptosis in the HRS cells of Hodgkin lymphoma has not been completely elucidated and is at variance with that in the consensus.     

Induction of apoptotic cell death specifically in rat and human cancer cells by pancratistatin

The major challenge in the battle against cancer is the specific targeting of cancer cells. Most chemotherapeutics and radiotherapies induce cancer cell death by inducing DNA damage. These treatments also cause severe side effects by affecting normal cells causing toxicity and mutations that may predispose them to become cancerous. Some non-genotoxic drugs such as tamoxifen are useful but are of limited applicability. Natural compounds such as paclitaxel have been useful in cancer treatment, but due to its effect as a general microtubule stabilizer and genotoxic agent, it also induces death of normal cells. Pancratistatin is a natural compound isolated from Pancratium littorale that has been shown to have anti-viral and anti-neoplastic activity. The objective in the present study was to elucidate the mechanism of the anti-neoplastic action of pancratistatin and evaluate the specificity of this compound for cancer cells. METHODS: We used cancer cell lines and normal human endothelial and fibroblast cells to investigate the effect of pancratistatin treatment. Further, we compared the toxic effects of paclitaxel and VP-16 to that of pancratistatin on non-cancerous cells. RESULTS: Pancratistatin induced apoptosis in all the cancer cell lines used in this study at sub-micromolar concentrations. Interestingly, normal human fibroblasts and endothelial cells remained unaffected by pancratistatin treatment under identical conditions whereas paclitaxel and VP-16 were both toxic to these two normal cell lines. CONCLUSION: The capability of pancratistatin to selectively induce apoptosis in cancer cells is an exciting finding and makes it a suitable anti-cancer agent. Since pancratistatin shows little structural similarity to any DNA intercalating drug or to paclitaxel derivatives, it appears to be non-genotoxic. Additionally, due to the unprecedented differential cytotoxicity observed in cancerous cells, we believe pancratistatin may act upon a novel target, allowing selective induction of apoptosis in cancer cells.     

B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma without mediastinal disease: mimicking nodular sclerosis classical Hodgkin lymphoma

B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma (BCLu-DLBCL/CHL), also known as gray-zone lymphoma, has overlapping clinical and biological characteristics of both diffuse large B-cell lymphoma and classical Hodgkin lymphoma (CHL). These lymphomas are typically associated with mediastinal disease, and extranodal involvement is rare. In the present report, we describe a case of a 78-year-old woman with BCLu-DLBCL/CHL found to have extranodal lesions and no evidence of mediastinal disease. Although biopsy specimens were histologically similar to nodular sclerosis CHL, the tumor cells were positive for CD30 and mature B-cell markers, such as CD20, CD79a, PAX5, BOB.1, and OCT-2, but negative for CD15. Furthermore, the patient had extranodal lesions and an increased level of soluble IL-2 receptor. These findings are unusual in CHL. Therefore, we diagnosed the patient with BCLu-DLBCL/CHL. She received adriamycin, bleomycin, vincristine, and dacarbazine therapy and exhibited partial response. Some cases without mediastinal disease, such as our case, have been reported; however, these cases are rare and further studies are required.     

Follicular dendritic cells in follicular lymphoma and types of non-Hodgkin lymphoma show reduced expression of CD23, CD35 and CD54 but no association with clinical outcome

Jin M K, Hoster E, Dreyling M, Unterhalt M, Hiddemann W & Klapper W
(2011) Histopathology  58 , 586–592
Follicular dendritic cells in follicular lymphoma and types of non‐Hodgkin lymphoma show reduced expression of CD23, CD35 and CD54 but no association with clinical outcome Aims: Follicular dendritic cells (FDC) are specialized antigen‐presenting cells found exclusively in the germinal centre (GC), which can be detected in B cell non‐Hodgkin lymphomas (NHL) as reactive bystander cells. Recently, gene expression profiling has revealed that FDC networks might be associated with clinical outcome in follicular lymphoma. The aim was to characterize FDC in NHL and to evaluate a possible association with outcome in follicular lymphoma. Methods and results: The extent and immunophenotype of FDC was determined semi‐quantitatively in reactive GC and NHL (follicular lymphoma, angioimmunoblastic T cell lymphoma, mantle cell lymphoma) using fluorescence double staining and digital image analysis. In all NHL tested CD23 and CD35 and CD54 were expressed at relatively low levels on FDC, comparable to FDC found in the dark zone of the GC. However, the extent of FDC networks did not correlate with the clinical outcome of 102 patients with follicular lymphomas treated within a prospectively randomized trial. Conclusions: FDC found in different types of NHL show quantitatively reduced expression of several proteins, suggesting that there are functional differences between FDC in normal GC and NHL. The extent of the FDC networks in follicular lymphoma is not useful as a prognostic marker.     

Timing determines dexamethasone and rituximab induced synergistic cell death

Dysregulation of cell death signaling pathways in many cell types such as B lymphocytes (B-cells) can lead to cancer, for example to B-cell lymphomas. Rituximab (RTX) and glucocorticoids such as dexamethasone (Dex) are widely used to treat hematological malignancies including B-cell lymphomas. Although the combination of Dex and RTX improves the treatment outcome of lymphoma patients, most lymphomas remain incurable diseases. Therefore, a detailed investigation of Dex- and RTX-induced signaling might provide new insights into the therapeutic benefits of these drugs. In this paper, we describe Dex- and RTX-induced signaling pathways and their downstream target proteins/cells. In addition, we also overview how the signaling initiated by Dex and RTX modulate the outcome of Dex- and RTX-mediated cell death in lymphoma cells.The combination of Dex and RTX results in massive cell death in lymphoma cells. However, pretreatment of lymphoma cells or mononuclear cytotoxic cells with Dex followed by RTX leads to a decrease in apoptosis or it impairs antibody-dependent cellular cytotoxicity (ADCC). RTX-mediated ADCC is impaired by Dex-induced depletion of cytotoxic cells, whereas RTX-mediated short-term ERK1/2 activation decreases Dex-induced apoptosis. Therefore, the timing of the combination of Dex and RTX is a determining factor for the synergistic effect of these cell death inducing agents.     

Monoamine oxidase A is highly expressed in classical Hodgkin lymphoma

Monoamine oxidase A (MAOA) is a mitochondrial enzyme that catalyzes oxidative deamination of neurotransmitters and dietary amines and produces H₂O₂. It facilitates the progression of gliomas and prostate cancer, but its expression and functional relevance have not been studied in lymphoma. Here, we evaluated MAOA in 427 cases of Hodgkin and non‐Hodgkin lymphoma and in a spectrum of reactive lymphoid tissues by immunohistochemistry on formalin‐fixed, paraffin‐embedded specimens. MAOA was expressed by Hodgkin Reed–Sternberg (HRS) cells in the majority of classical Hodgkin lymphomas (cHLs) (181/241; 75%), with 34.8% showing strong expression. Weak MAOA was also noted in a minority of primary mediastinal large B‐cell lymphomas (8/47; 17%) and in a mediastinal gray‐zone lymphoma. In contrast, no MAOA was found in non‐neoplastic lymphoid tissues, nodular lymphocyte‐predominant Hodgkin lymphoma (NLPHL; 0/8) or any other non‐Hodgkin lymphomas studied (0/123). MAOA was more common in Epstein–Barr virus (EBV)‐negative compared to EBV‐positive cHL (p < 0.0001) and was especially prevalent in the EBV‐negative nodular sclerosing subtype. Similar to primary human lymphoma specimens, most cHL‐derived cell lines displayed MAOA activity, whereas non‐Hodgkin‐lymphoma‐derived cell lines did not. The MAOA inhibitor clorgyline reduced the growth of L1236 cells and U‐HO1 cells, and shRNA knockdown of MAOA reduced the growth of L1236 cells. Conversely, ectopic overexpression of MAOA increased the growth of MAOA‐negative HDLM2 cells. Combined treatment with clorgyline and ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) was more effective in reducing cell growth than either regimen alone. In summary, MAOA is highly expressed in cHL and may reflect the distinct biology of this lymphoma. Further studies on the potential utility of MAOA as a diagnostic marker and therapeutic target are warranted. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

自噬减轻模拟缺血/再灌注微环境中肺微血管内皮细胞损伤

目的:观察体外模拟缺血/再灌注(ischemia/reperfusion,I/R)微环境下人肺微血管内皮细胞(human pulmonary microvascular endothelial cells,HPMVECs)的自噬变化,研究自噬在维持I/R条件下HPMVECs细胞存活及内皮屏障完整性中的作用。方法:用雷帕霉素(rapamycin,RAP)预处理HPMVECs,在缺糖缺氧/恢复糖和氧供(oxygen-glucose deprivation/oxygen-glucose restoration,OGD)模拟的I/R微环境中孵育细胞。应用Western blot及透射电镜法检测细胞自噬变化,用流式细胞术检测细胞凋亡,通透性小室法检测HPMVECs通透性。结果:OGD条件下HPMVECs的自噬水平明显升高,RAP预处理进一步上调了OGD条件下的细胞自噬。OGD组细胞凋亡率明显增高,细胞通透性增加。RAP预处理不仅降低了OGD引起的细胞凋亡率,而且减轻了OGD条件下细胞通透性。结论:自噬在I/R诱发的肺微血管内皮细胞损伤中发挥保护性作用,提高自噬水平有助于减少I/R条件下细胞凋亡并维持内皮屏障完整性。     

Programmed death 1 expression in variant immunoarchitectural patterns of nodular lymphocyte predominant Hodgkin lymphoma: comparison with CD57 and lymphomas in the differential diagnosis

Recent studies have exploited an antibody directed against programmed death 1 expressed by follicular helper T-cells in the diagnosis of nodular lymphocyte predominant Hodgkin lymphoma. We had previously described clinically relevant, variant immunoarchitectural patterns of nodular lymphocyte predominant Hodgkin lymphoma and, in this study, sought to address the diagnostic utility of programmed death 1 in comparison with CD57 in variant nodular lymphocyte predominant Hodgkin lymphoma. Immunohistologic staining for programmed death 1 was carried out on biopsies of 67 patients with variant nodular lymphocyte predominant Hodgkin lymphoma. Thirty-four additional cases of nodular lymphocyte predominant Hodgkin lymphoma with associated diffuse areas, de novo T-cell and histiocyte-rich large B-cell lymphoma, and lymphocyte-rich classic Hodgkin lymphoma were also studied. Our results show that programmed death 1 positivity was found in the majority of nodular lymphocyte predominant Hodgkin lymphoma cases with a classic nodular architecture (87%) as compared with 50% for CD57 and was particularly helpful in identifying extranodular large atypical cells. Nodular lymphocyte predominant Hodgkin lymphoma with diffuse areas showed a gradual decrease in programmed death 1 reactivity from nodular to diffuse areas, although a significant proportion (40%-50%) of cases retained programmed death 1 positivity also in diffuse areas. In addition, T-cell and histiocyte-rich large B-cell lymphoma and lymphocyte-rich classic Hodgkin lymphoma displayed programmed death 1 positivity in a significant subset of cases (33%-40%). In conclusion, our study supports the utility of programmed death 1 in the diagnosis of nodular lymphocyte predominant Hodgkin lymphoma and shows greater sensitivity of staining of programmed death 1 as compared with CD57 across all variants of nodular lymphocyte predominant Hodgkin lymphoma. Loss of programmed death 1 reactivity did not correlate with diffuse areas, progression, or the ability to differentiate nodular lymphocyte predominant Hodgkin lymphoma from T-cell and histiocyte-rich large B-cell lymphoma. These findings suggest the need for continued vigilance in the diagnosis of nodular lymphocyte predominant Hodgkin lymphoma and its immunoarchitectural variants as well as related lymphomas in their differential diagnosis.     

3-甲基腺嘌呤对喜树碱诱导的宫颈癌Hela 细胞凋亡的影响

目的:本研究探讨自噬抑制剂3-甲基腺嘌呤(3-methyladenine,3-MA)对喜树碱(Camptothecin,CPT)诱导的Hela 细胞凋亡的影响。方法:用四甲基偶氮唑盐比色法(MTT 方法)检测CPT 对Hela 细胞作用的最佳药物浓度和时间,以及不同药物对Hela 细胞增殖活性的影响;用免疫印迹及免疫荧光检测不同药物作用于Hela 细胞后,Hela 细胞自噬标志蛋白微管相关蛋白1 轻链3(microtubule-associated protein 1 light chain 3,LC3)、p62 及凋亡相关蛋白的变化;DAPI 核染色观察细胞凋亡。结果:CPT 作用于Hela 细胞后,Hela 细胞增殖活性明显下降,并且可诱导自噬现象的发生。CPT 和3-MA 联合作用较单独CPT 作用Hela 细胞的增殖活性降低,细胞自噬水平下降,凋亡率明显升高。结论:CPT 在诱导Hela 细胞凋亡的同时可诱导自噬,通过3-MA 抑制自噬可增强Hela 细胞对CPT 作用的敏感性。     

Cytotoxic effects of Cuscuta extract on human cancer cell lines

Cancer is a growing health problem around the world. Although there are different therapeutic methods for cancer such as lymphoma and melanoma cancers, none of them have possessed complete efficacy up to now. Therefore, discovery of novel anti-cancer drugs is important. In this study, the cytotoxic effect of Cuscuta extract, a traditional Iranian medicinal herb, on melanoma cell line (SK-MEL-3) and human Burkitt lymphoma (Raji) is evaluated. MTT assay was performed for cytotoxic effect of Cuscuta extract. The most cytotoxic effects of Cuscuta extract on SK-MEL-3 and Raji cell lines were 80 and 81%, respectively, compared to a control group. According to our data, Raji cells are more sensitive to Cuscuta than the SK-MEL-3 cells. Cuscuta extract seems to be a good candidate as an anti-cancer agent against lymphoma and melanoma cancers. To clarify the effective molecules and their mechanisms, further studies are undertaken in our laboratory on animal models and humans.     

甲基硒酸对人三阴性乳腺癌细胞化疗增敏作用的机制探讨

 目的：观察甲基硒酸（methylseleninic acid,MSA）对人三阴性乳腺癌细胞的化疗增敏作用及其机制。方法：采用MSA联合紫杉醇、阿霉素与三阴性乳腺癌MDA-MB-231细胞株共培养,分别应用CCK-8实验检测化疗药物单药和联合MSA用药时细胞增殖抑制率,并通过计算合用指数,探讨MSA对化疗药物疗效的影响;用流式细胞术检测细胞周期的分布情况;应用Annexin V-FITC/PI双染法检测细胞凋亡变化。结果：不同浓度化疗药物联合MSA后细胞增殖率较单用化疗药物组均下降,呈明显的量－效关系,提示MSA与化疗药物具协同作用;紫杉醇联合MSA时G2/M期细胞较单药明显增多(P<005),阿霉素联合MSA时S期细胞较单药明显增多(P<005),提示MSA增强了抗肿瘤药物诱导的肿瘤细胞周期阻滞效应;与单用同一浓度的同一化疗药物相比,10 nmol/L紫杉醇联合35 μmol/L MSA后细胞凋亡率由41.1%上升至59.3%（P<005）,0.5 μmol/L阿霉素联合35 μmol/L MSA后细胞凋亡率由30.2%上升至51.9%（P<0.01）,提示MSA增强了抗肿瘤药物诱导肿瘤细胞凋亡的效应。结论：MSA能增强化疗药物阿霉素和紫杉醇对三阴乳腺癌细胞的抗肿瘤效果,其机制之一可能是增强了抗肿瘤药物诱导的肿瘤细胞凋亡和周期阻滞效应。     

吉西他滨对肺微血管内皮细胞的损伤及表没食子儿茶素没食子酸酯的保护作用

目的 观察吉西他滨对大鼠肺微血管内皮细胞的影响及表没食子儿茶素没食子酸酯的保护作用。 方法 利用植块法分离大鼠肺微血管内皮细胞。SRB 法检测药物对肺微血管内皮细胞和 A549增殖的影响。流式细胞仪用于检测细胞周期和细胞凋亡。Western blot 法检测凋亡相关蛋白含量。测定细胞内活性氧和超氧化物歧化酶水平以及乳酸脱氢酶渗透情况。 结果 吉西他滨能显著减少肺微血管内皮细胞细胞增殖并将其阻滞于 S 期。吉西他滨引起肺微血管内皮细胞细胞凋亡具有时间依赖性,处理24、48、72 h 后细胞凋亡率分别为7.2%、15.4%、23.3%。同时,吉西他滨作用后细胞内活性氧含量上升,而处理48 h 后超氧化物歧化酶水平显著下降。进一步研究发现,表没食子儿茶素没食子酸酯能够提高吉西他滨处理后肺微血管内皮细胞的存活率,并且减弱吉西他滨造成的超氧化物歧化酶水平的下降。 结论 吉西他滨对肺微血管内皮细胞具有损伤作用,能够引起肺微血管内皮细胞的凋亡和氧化应激的发生,而表没食子儿茶素没食子酸酯对吉西他滨引起的肺微血管内皮细胞损伤具有保护作用。