Expression of Telomerase Subunits in Gastric Cancer

To detect the expression of telomerase subunits （human telomerase reverse transcriptase, human telomerase associated protein 1 and human telomerase RNA） in gastric cancer and to examine the role that different telomerase subunits play in the gastric carcinogenesis, reverse transcription-polymerase chain reaction （RT-PCR） was used to detect telomerase suhunits messenger RNA in 24 samples of gastric cancer and corresponding non-cancerous tissue. The results showed that the positive rate of hTERT mRNA from gastric cancer and corresponding non-cancerous tissues was 100% and 25 %, respectively. The former was significantly higher than the latter （X^2 = 26.4, P〈0.01）. The positive rate of hTEP1 mRNA from gastric cancer and corresponding non-cancerous tissues was 100 % and 91.7%, respectively and no significant difference was found between them （X^2 =2.1, P〉0.05）. The positive rates of hTR for gastric cancer and corresponding non-cancerous tissues were both 100 % and no significant difference existed between them. It is concluded that in contrast to hTEP1 and hTR, the up-regulation of hTERT mRNA expression may play a more important role in the development of gastric cancer.

Telomeres,telomerase and colorectal cancer

Colorectal cancer(CRC)is the third most common cancer worldwide and,despite improved treatments,is still an important cause of cancer-related deaths.CRC encompasses a complex of diseases arising from a multistep process of genetic and epigenetic events.Besides heterogeneity in the molecular and biological features of CRC,chromosomal instability is a hallmark of cancer and cancer cells may also circumvent replicative senescence and acquire the ability to sustain unlimited proliferation.Telomere/telomerase interplay is an important mechanism involved in both genomic stability and cellular replicative potential,and its dysfunction plays a key role in the oncogenetic process.The erosion of telomeres,mainly because of cell proliferation,may be accelerated by specific alterations in the genes involved in CRC,such as APC and MSH2.Although there is general agreement that the shortening of telomeres plays a role in the early steps of CRC carcinogenesis by promoting chromosomal instability,the prognostic role of telomere length in CRC is still under debate.The activation of telomerase reverse transcriptase(TERT),the catalytic component of the telomerase complex,allows cancer cells to grow indefinitely by maintaining the length of the telomeres,thus favouring tumour formation/progression.Several studies indicate that TERT increases with disease progression,and most studies suggest that telomerase is a useful prognostic factor.Plasma TERT mRNA may also be a promising marker for the minimally invasive monitoring of disease progression and response to therapy.

Telomere erosion is independent of microsatellite instability but related to loss of heterozygosity in gastric cancer

AIM To correlate the length of the telomere to microsatellite instability (MSI) and loss of heterozygosity (LOH) of APC, MCC and DCC genes in gastric carcinomas.METHODS Telomeric restriction fragment (TRF) length of gastric cancer was measured with Southern blot. LOH of APC, MCC and DCC genes, microsatellite instability (MSI) and frameshift mutation of hMSH6, TGF-βR Ⅱ and BAX genes were analyzed by PCR-based methods.RESULTS Sixty-eight cases of sporadic gastric carcinoma were studied for MSI using five microsatellite markers. MSI in at least one locus was detected in 17 (25%) of 68 tumors analyzed. Frameshift mutations of hMSH6, TGF-βR Ⅱ and BAX were detected in 2,6 and 3 of gastric carcinomas respectively showing high MSI (≥ 2 loci, n = 8), but none was found in those showing Iow MSI (only one locus, n = 9) or MSS (tumor lacking MSI or stable, n = 51). Thirty-five cases, including all high MSI and Iow MSl, were studied for TRF. The mean TRF length was not correlated with clinicopathological parameters.No association was observed between TRF length and MSI or frameshift mutation. On the contrary, LOH at the DCC locus was related to telomere shortening (P＜ 0.01). This tendency was also observed in APC and MCC genes,although there was no statistical significance.CONCLUSION The development of gastric cancer can arise through two different genetic pathways. In high MSI gastric cancers, defective mismatch repair allows mutations to accumulate and generate the high MSI phenotype. In gastric cancers showing either Iow MSI or MSS, multiple deletions may represent the LOH pathway.Telomere erosion is independent of high MSI phenotype but related to the LOH pathway in gastric cancer.

Telomerase and hTERT: Can they serve as markers for gastric cancer diagnosis?

AIM:To investigate telomerase activity and human telomerase reverse transcriptase(hTERT)expression in normal human gastric mucosal epithelial cells(nhGMECs)and fibroblasts(nhGMFs).METHODS:nhGMECs and nhGMFs were isolated and cultured from specimens obtained during routine surgery for bleeding peptic ulcer.Telomerase activity in nhGMFs,nhGMECs,and the tumor cell lines BGC-823,SGC-7901 and MKN-28 cells was analyzed using the telomeric repeat amplification protocol assay.hTERT protein was determined in nhGMECs,nhGMFs,BGC-823,SGC-7901 and MKN-28 cells by indirect immunofluorescence.served in nhGMECs,nhGMFs and BGC-823,SGC-7901,MKN-28 cell lines.Positive hTERT immunostaining was detected in nhGMECs,nhGMFs,BGC-823,SGC-7901and MKN-28 cell lines.CONCLUSION:The use of telomerase or hTERT as diagnostic markers for gastric cancer may require further studies.

Expression of Telomerase Activity in Gastric Cancer Cells

Objective To study the relationship between telomerase activity and biological behavior in human gastric cells and appraise the clinical significance of detecting telomerase activity. Methods The telomerase activity in 47 gastric cancer tissue samples,their matched nomal tissues,7 gastric ulcer and 2 gastric cancer cell lines was detected using a PCR-based non-radioisotopic telomeric repeat amplification protocol(TRAP) assay. Results None of the 47 samples from normal gastric tissues expressed telomerase activity.The 41 of 47 cases of gastric cancer presented telomerase activity with an 87.2% positive rate (P<0.001). 2/2 gastric cancer cell lines and 0/7 gastric ulcer line were also positive for telmerase activity.The activity of telomerase was associated with the pathological differentiation of gastric cancer. Conclusion Telomerase activity may be related to the biological behavior of gastric cancer and can help in assessing the malignant poten-tial of gastric cancer.Telomerase activity will be a good diagnostic marker for the detection of gastric cancer.

Determination of telomerase activity and its clinical significance in gastric cancer and premalignant lesions

In order to explore the role of telomerase activity (TA) in the development and progression of gastric cancer (GC) and if TA can be used as an indicator for the early diagnosis of GC, TA in 176 specimens of gastric mucosa of 57 cases of chronic atrophic gastritis (CAG), 18 intestinal metaplasia (IM), 8 dysplasia (Dys), 65 GC obtained through operation or endoscopy was determined with PCR-based TRAP assay. Meanwhile, operative specimens of GC were analyzed with serial dilution. It was found that TA was detected in 24. 6% of CGA, 38. 9% of IM, 37.5% of Dys and 92.3% of GC, but not detected in 28 cases of normal tissues. TA detection was not related to patients’ sex, tumor location, size, depth of invasion, differentiation, lymph node metastasis and clinicalstage. Telomerase activity in premalignant lesions indicates that it plays a crucial role in the development and progression of GC. Thus the determination of telomerase activity is helpful to predict the progress of premalignant changes and to diagnose early GC.

Clinical significance of telomerase activity in peritoneal lavage fluid from patients with gastric cancer and its relationship with cellular proliferation

AIM: To evaluate the efficacy of telomerase activity assay and peritoneal lavage cytology (PLC) examination in peritoneal lavage fluid for the prediction of peritoneal metastasis in gastric cancer patients, and to explore the relationship between telomerase activity and proliferating cell nuclear antigen expression. METHODS: Telomeric repeated amplification protocol (TRAP)-enzyme-linked immunosorbent assay (ELISA) was performed to measure the telomerase activity in 60 patients with gastric cancer and 50 with peptic ulcer. PLC analysis of the 60 patients with gastric cancer was used for comparison. The proliferating cell nuclear antigen (PCNA) in gastric carcinoma was immunohistochemically examined. RESULTS: The telomerase activity and PLC positive rate in peritoneal lavage fluid from patients with gastric cancer was 41.7/ (25/60), and 25.0/ (15/60), respectively. The positive rate of telomerase activity was significantly higher than that of PLC in the group of pT4 (15/16 vs 9/16, P < 0.05), P1-3 (13/13 vs 9/13, P < 0.05) and diffuse type (22/42 vs 13/42, P < 0.05). The patients with positive telomerase activity, peritoneal metastasis, and serosal invasion had signifi cantly higher levels of average PCNA proliferation index (PI), (55.00 ± 6.59 vs 27.43 ± 7.72, 57.26 ± 10.18 vs 29.15 ± 8.31, and 49.82 ± 6.74 vs 24.65 ± 7.33, respectively, P < 0.05).CONCLUSION: The TRAP assay for telomerase activity is a useful adjunct for cytologic method in the diagnosis of peritoneal micrometastasis and well related to higher proliferating activity of gastric cancer. The results of this study also suggest a promising future therapeutic strategy for treating peritoneal dissemination based on telomerase inhibition.

Clinical significance of telomerase and its associate genes expression in the maintenance of telomere length in squamous cell carcinoma of the esophagus

AIM: To observe the interaction between the expression of telomerase activity (TA) and its associate genes in regulation of the terminal restriction fragment length(TRFL) in esophageal squamous cell carcinoma (SCC).METHODS: Seventy-four specimens of esophageal SCC were examined. The TA was measured by telomeric repeat amplification protocol (TRAP) assay, and the associated genes [human telomerase-specific reverse transcriptase (hTERT), hTERC, TP1, c-Myc, TRF1,and TRF2] were detected using RT-PCR method. The TRFL was measured by Telomere Length Assay Kit and Southern blotting. The correlations between the expression of telomerase and its associated genes with the TRFL and survivals were examined.RESULTS: Expressions of the TA, hTERT, hTERC, TP1,c-Myc, TRF1, and TRF2 genes were observed in 85.1%,64.9%, 79.7%, 100.0%, 94.6%, 82.4%, and 91.9% of the tumor tissues, respectively. The TRFL of the tumor and normal esophageal tissues were 2.70±1.42 and 4.93±1.74 kb, respectively (P＜0.0001). The TRFL of the telomerase positive and telomerase negative tumor tissues were 2.72±1.44 and 2.58±1.32 kb, respectively (P = 0.767).The TRFL ratios (TRFLR) of the telomerase positive and telomerase negative tumor tissues were 0.55±0.22 and 0.59±0.41, respectively (P = 0.742). The expression rates of h-TERT (P = 0.0002), hTERC (P＜0.0001), and TRF1(P = 0.002) in the tumor tissues are higher than those of the normal paired tissues. Though TA is markedly activated in tumor tissues (P＜0.0001), its expression is not related to clinicopathological parameters including gender, tumor differentiation, and TNM stages. The cumulative 4-year survival rates of telomerase positive and telomerase negative cases were 35.86% and 31.2%,respectively (P = 0.8442). The cumulative 4-year survival rates of patients with their TRFLR ≤85% and ＞85%were 38.7% and 15.7%, respectively (P = 0.1307).CONCLUSION: Though telomerase expression is not related to tumor stages and prognosis, our data support that the TA increased as the TRFL decreased,probably under the control of hTERT, hTERC, and TRF1.When telomerase expression was activated, only TRF2overexpression persisted to stabilize T-loop formation.Furthermore, as the TRFLR decreased to 85%, a trend of better prognosis was observed. Cox model analysis indicates a higher t/n TRFLR and distant metastasis are independent poorer prognostic factors (P = 0.035 and P = 0.042, respectively).

Telomerase reactivation is associated with hepatobiliary and pancreatic cancers

Background:Human telomerase reverse transcriptase(hTERT)and its components play a significant role in cancer progression,but recent data demonstrated that telomeres and telomerase alterations could be found in other diseases;increasing evidence suggests a key role of this enzyme in the fields of hepatobiliary and pancreatic diseases.Data sources:We performed a PubMed search with the following keywords:telomerase,hepatocellular carcinoma,cholangiocarcinoma,pancreatic adenocarcinoma by December 2019.We reviewed the relevant publications that analyzed the correlation between telomerase activity and hepatobiliary and pancreatic diseases.Results:Telomerase reactivation plays a significant role in the development and progression of hepatobiliary and pancreatic tumors and could be used as a diagnostic biomarker for hepatobiliary and pancreatic cancers,as a predictor for prognosis and a promising therapeutic target.Conclusions:Our review summarized the evidence about the critical role of hTERT in cancerous and precancerous lesions of the alteration and its activity in hepatobiliary and pancreatic diseases.

Genetic Variation of <i>hTERT</i>, Leukocyte Telomere Length and the Risk of Breast Cancer: A Case-Control Study in Egyptian Females

Background: hTERT is a key player in telomere biology and its activity is directly related to cell senescence and development of many health-related problems including cancer. Although previous studies investigated this association, the results greatly vary among populations. This study aimed to investigate the association of hTERT gene SNPs and the risk of breast cancer (BC) in Egyptian females and their impact on telomere length (TL). Methods: 218 BC patients and 178 age-matched healthy females were genotyped for hTERT variants rs2736098G > A, rs2735940C > T using PCR-RFLP and for MNS16A tandem repeat using PCR to determine their association with breast cancer risk. Telomere length was measured using qPCR. Results: hTERT rs2736098G > A results indicated that both AG and GG genotypes and G allele were associated with an increased risk of BC. The rs2735940 TT genotype was significantly associated with BC risk, however, the MNS16A tandem repeat region polymorphism didn’t show any correlation with the risk of developing BC. TL showed a significant reduction in BC patients with age 40 years compared with controls. However, it didn’t show a significant difference above the age of 40 years. Conclusions: hTERT rs2736098 and rs27365940, not MNS16A may be associated with an increased risk of developing BC in Egyptian females. Also, telomere length can be a promising screening marker of BC especially in young population.

Telomerase enzyme in aging and cancer

Telomerase is an enzyme that maintains the length of telomeres at the ends of chromosomes.Telomeres are protective caps at the ends of chromosomes that keep genetic information intact,enable cells to multiply and provide insight into some of the mysteries of ageing and cancer.Telomerase activity affects ageing and cancer development in humans by preventing telomeres from becoming too short,which can lead to cellular senescence and death.When telomerase is suppressed,cancer cells die,and telomerase inhibitors can be used to kill human breast and prostate cancer cells grown in the laboratory.Studies have also found an association between shorter telomeres,a decreased overall lifespan,and an increased risk of cardiovascular disease and infectious illness.Despite research linking telomere shortening to the ageing process,additional research is needed to fully understand the role of telomerase in the ageing process,including whether or not it is the cause of these changes.Other variables,such as oxidative stress,glycation,and inflammation,also contribute to the ageing process and may explain the remaining 33 percent of the variance in the probability of passing away.The authors of this paper discuss the current understanding of telomerase enzyme activity and its effects on ageing and cancer,as well as the implications of telomerase research and the potential for developing innovative drugs and gene therapies.

TGF-beta receptor mediated telomerase inhibition, telomere shortening and breast cancer cell senescence

Human telomerase reverse transcriptase （hTERT） plays a central role in telomere lengthening for continuous cell proliferation, but it remains unclear how extracellular cues regulate telomerase lengthening of telomeres. Here we report that the cytokine bone morphogenetic protein-7 （BMP7） induces the hTERT gene repression in a BMPRII receptor- and Smad3-dependent manner in human breast cancer cells. Chonic exposure of human breast cancer cells to BMP7 results in short telomeres, cell senescence and apoptosis. Mutation of the BMPRII receptor, but not TGFbRII, ACTRIIA or ACTRIIB receptor, inhibits BMP7-induced repression of the hTERT gene promoter activity, leading to increased telomerase activity, lengthened telomeres and continued cell proliferation. Expression of hTERT prevents BMP7-induced breast cancer cell senescence and apoptosis. Thus, our data suggest that BMP7 induces breast cancer cell aging by a mechanism involving BMPRII receptor- and Smad3-mediated repression of the hTERT gene.

Long-term prognostic impact of circulating tumour cells in gastric cancer patients

AIM To analyse the long-term prognostic impact of circulating tumour cells(CTCs) in gastric cancer patients who underwent surgery. METHODS A 7.5-m L peripheral vein blood sample was obtained from each patient with treatment-negative gastric adenocarcinoma before surgery. OBP-401, a telomerasespecific, replication-selective, oncolytic adenoviral agent carrying the green fluorescent protein gene, was used to label CTCs. Correlations between the number of CTCs and clinical end points were evaluated. RESULTS The median follow-up period of the surviving patients with gastric cancer was 60 mo. The CTC number tended to increase concomitantly with disease progression. The overall survival of patients with more than five CTCs in 7.5-m L of peripheral blood was lower than that of patients with five or less CTCs, although the difference was not significant(P = 0.183). A significant difference in relapse-free survival was found between patients with more than five and those with five or less CTCs(P = 0.034).CONCLUSION A lower number of CTCs was correlated with higher relapse-free survival rates in patients. Detection of CTCs using OBP-401 may be useful for predicting prognosis in gastric cancer.

Inhibition of the proliferation of human gastric cancer cells SGC-7901 in vitro and in vivo using Bcl-2 siRNA

Background Bcl-2, the anti-apoptotic protein is overexpressed in the majority of gastric cancers and associated with its pathogenesis. To better understanding of the role of Bcl-2, RNA interference （RNAi） was used to inhibit Bcl-2 expression in the human gastric cancer cells in vitro and in vivo. Methods Bcl-2 small interfering RNA （siRNA） was transfected into human gastric cancer cells $GC-7901, and Bcl-2 expression was monitored by real-time polymerase chain reaction （PCR） and Western blot. Cell proliferation, apoptosis, and telomerase activity were examined by MTT, flow cytometry, and TRAP assay, respectively. Gastric cancer cells treated with 100 nmol/L Bcl-2 siRNA were subcutaneously transplanted into nude mice and tumor growth was assessed. Results Bcl-2 siRNA significantly inhibited the expression of Bcl-2 in human gastric cancer cells at both mRNA and protein levels in a time- and dose-dependent manner. Bcl-2 siRNA also decreased telomerase activity （by 78.76%） and increased the rate of apoptosis （by 37.47%）. SGC-7901 cell growth was also significantly suppressed in vivo and in vitro. Conclusions Bcl-2 expression knockdown suppressed the growth of gastric cancer cells. Thus, Bcl-2 may play a very important role in carcinogenesis of gastric cancer and its knockdown may offer a new potential gene therapy approach for human gastric cancer in future.

Peptide nucleic acids arrest the growth of gastric cancer cells SGC7901

Background Peptide nucleic acid (PNA) has many characteristics useful in molecular biology. This paper described an effective way to raise the cell ingestion rate of PNA so as to kill gastric cancer cells. Methods Heteroduplexes of PNAs and oligonucleotides, wrapped by Lipofectamine 2000, were used to infect SGC7901 cells. The inhibitive effect of heteroduplexes was evaluated by analyzing cell clone forming and cell growth rate. Telomerase activity of SGC7901 cells was detected by polymerase chain reaction enzyme-linked immunosorbent assay (PCR-ELISA) and silver staining assay.Results PNAs showed a dose-dependent inhibition of cell proliferation. The percentage of proliferation inhibition was 99.4% after 7 days; the rate of cloning inhibition was 98.2% after 8 days; whereas for oligonucleotide groups, at the same concentration, the percentages were 50.1% and 67.5% respectively. Antisense PNA-DNA-Lipofectamine 2000 group (AP-D-L group) exhibited significantly different percentages from the control groups (P<0.05). The test result indicated that telomerase activity of the AP-D-L group was inhibited (P<0.05). At the same time, the impact on cell morphology was observed. Conclusions The results showed that PNAs are potent antisense reagents. The telomerase-associated therapies are very promising for the treatment of malignant tumours.

Study on the Mechanism of Xiaotan Sanjie Recipe for Inhibiting Proliferation of Gastric Cancer Cells

Objective:To explore the mechanism of Xiaotan Sanjie Recipe (XtSjR, Recipe for dissolving phlegm to eliminate stagnation) in inhibiting proliferation of gastric cancer cells. Methods: The nude mouse human gastric cancer MKN-45 in situ transplantation tumor model was established by use of OB glue, and 40 model mice were randomized into 5 groups, model group, low-dose XtSjR group, middle-dose XtSjR group, high-dose XtSjR group, and 5-Fu group, 8 rats in each group. Human gastric cancer MKN-45 telomerase reverse transcriptase (hTERT) protein and mRNA expressions were assayed by immunohistochemical method and real-time fluorescence quantitative RT-PCR, and influences of XtSjR on the expressions of hTERT protein and mRNA were investigated in the nude mouse human gastric cancer MKN-45 in situ tumor transplantation model. Results: 1) There were significant differences in the mean tumor weight between the low-, middle-, high-dose XtSjR groups and the model group (all P<0.01); 2) There were significant differences in the hTERT positive expression rate between the middle-and high-dose XtSjR groups and the model group (P<0.05 or P<0.01); 3) There were significant differences in the hTERT mRNA content between the middle-and high-dose XtSjR groups and the model group (P<0.05 or P<0.01). Conclusion: 1) XtSjR has a marked inhibitory effect on the growth of gastric cancer cells; 2) XtSjR inhibits telomerase activity by down-regulating the expressions of hTERT protein and mRNA, shortening the length of cancer cell telomeres gradually, losing the ability to infinitely proliferate, and finally inhibiting the growth and proliferation of tumor cells.

胃癌中端粒相关基因亚型鉴定、预后模型构建以及免疫细胞浸润分析

目的本研究旨在基于对端粒相关基因(Telomere related genes,TRG)表达数据的综合分析,探讨预后分子特征以预测胃癌(GC)的预后及与免疫细胞浸润的关系。方法联合TCGA与GEO数据库对胃癌端粒相关基因进行生存分析及预后相关性分析。通过无监督聚类确定两个端粒相关基因簇,依据Lasso回归及多因素cox回归分析构建预后模型,结合临床性状构建列线图预测患者生存期,同时进行风险差异分析,运用ROC曲线评估模型预测准确性,对样本进行免疫细胞浸润分析。结果构建了包含HEYL、SPC25、SRPX2、PDK4、LOXL4、SOX15、SLC39A4、MAGEA3、SHISA2、DEFB1、SLC27A2和C1QTNF5等12个基因的预后模型来评估胃癌患者的预后,构建了整合风险特征的列线图来预测胃癌患者的1年、3年和5年总生存期(OS),高风险组的生存率显著低于低风险组(P<0.05),不同风险组的免疫细胞亚型比例不同。结论这项研究鉴定了胃癌中TRG衍生的分子亚型,并开发了一种新的预后评分模型,突出了TRG在胃癌预后和免疫治疗中的潜在价值。

端粒酶与肿瘤相关性研究进展

端粒是一段存在于真核细胞染色体末端,随着细胞分裂而缩短的特殊结构。端粒酶可延长端粒,但在正常人体细胞内活性较低或无活性。大多数肿瘤细胞通过激活端粒酶活性,延伸端粒达到细胞无限增殖的可能。端粒酶的活性与肿瘤的发生密切相关。本文以近年来临床常见的恶性肿瘤为出发点,综述了其与端粒酶活性关系及端粒酶抑制剂的最新研究。

端粒酶TERT通过向线粒体转位抵抗胃癌细胞铁死亡的发生机制

目的:探究胃癌细胞铁死亡发生时,端粒酶TERT如何抵抗铁死亡的发生。方法:提取胃癌细胞BGC823的线粒体及细胞总蛋白,通过蛋白质印迹实验检测10μmol/L erastin处理细胞后,铁死亡相关蛋白SLC7A11、谷胱甘肽过氧化物酶4(GPX4)及端粒酶蛋白TERT表达量的变化以及线粒体中TERT含量变化;通过免疫荧光实验检测TERT是否定位于线粒体;使用5μmol/L bosutinib预处理细胞后再加入10μmol/L erastin处理细胞,通过免疫荧光实验检测TERT与线粒体定位情况;通过活性氧簇(ROS)检测试剂盒、丙二醛(MDA)检测试剂盒、Fe^(2+)检测试剂盒分别检测ROS、MDA、Fe^(2+)含量变化;通过CCK-8及划痕实验检测细胞生长、增殖及迁移能力。结果:蛋白质印迹实验结果显示,GPX4(t=15.30,P<0.001)、SLC7A11(t=5.228,P<0.01)、TERT(t=3.682,P<0.05)水平明显降低,线粒体中TERT含量降低(t=6.736,P<0.001)。免疫荧光实验结果显示,TERT定位于线粒体,联合用药组细胞免疫荧光实验结果显示TERT更多的定位在细胞核。联合用药组与单独用药组相比,铁死亡指标ROS(t=4.109,P<0.05)、MDA(t=6.491,P<0.01)、Fe^(2+)(F=9.703,P<0.01)含量均升高,CCK-8(F=4.706,P<0.05)及划痕实验(t=4.631,P<0.05)结果显示细胞增殖、迁移能力进一步降低。结论:铁死亡发生时,TERT由细胞核向线粒体进行转位,使用bosutinib抑制TERT向线粒体转位后,铁死亡相关指标增强,抑制TERT转位可以增强铁死亡的发生,抑制胃癌细胞生长、增殖。

Erastin和BIBR1532联合应用对胃癌细胞增殖的影响

目的:探究Erastin和BIBR1532(端粒酶抑制剂)联合应用对胃癌细胞增殖的影响。方法:使用TIMER2.0、GEPIA2.0数据库比较胃癌组织和相应的正常胃黏膜组织中谷胱甘肽过氧化物酶(GPX4)基因的表达水平,并通过GEPIA2.0预测GPX4是否影响胃癌患者的生存和预后。利用STRING数据库构建GPX4蛋白相互作用网络。10、20μmol/L Erastin干扰GPX4表达,通过Western印迹及TRAP(端粒酶活性测定)实验检测TERT蛋白表达量以及端粒酶活性的变化。应用CCK8增殖实验、克隆形成实验检测细胞活力。结果:TIMER2.0和GEPIA2.0数据库检索结果显示胃癌组织中的GPX4表达水平明显高于正常组织,高水平的GPX4与胃癌患者不良预后相关(P<0.05)。STRING蛋白相互作用网络分析显示,GPX4蛋白相互作用网络包括TERT、SLC7A11、PINX1、HSP90AA1、DKC1、SLC3A2、SMARCA4、PIF1、CTNNB1、WRAP53、SMG6、RUVBL1。10、20μmol/L Erastin干扰GPX4蛋白表达后,TRAP实验结果显示细胞端粒酶活性明显降低(t=34.29、14.28,均P<0.001),Western印迹结果显示TERT蛋白表达量明显降低(t=3.599、8.144,均P<0.05)。CCK8和克隆形成实验结果显示细胞生长增殖能力降低(t=8.662、27.88,均P<0.001)。10μmol/L Erastin与75μmol/L BIBR1532联合使用导致胃癌细胞端粒酶活性和TERT蛋白表达量进一步降低(t=9.931、4.918,均P<0.01),导致细胞增殖能力降低更明显(t=4.157、25.46,均P<0.05)。结论:GPX4在胃癌组织中高表达,Erastin和BIBR1532联合使用在干扰GPX4表达的同时,细胞内端粒酶活性和TERT蛋白表达量进一步降低,抑制胃癌细胞增殖。