Aberrant FHIT expression is linked to bladder carcinogenesis and apoptosis

The fragile histidine triad gene (FHIT) functions as tumor suppressor in many epithelial cell types. Although the exact mechanisms remain unclear, it is apparent that in its absence, cell cycle homeostasis is often perturbed resulting in the development of soft tissue tumors. Here, we investigated the role of FHIT expression in bladder carcinogenesis and progression using immunohistochemistry. Bladder carcinoma tissue and the 5637 cell line were also studied for FHIT expression by RT-PCR and Western blotting, respectively. FHIT was found to be expressed in carcinoma and adjacent normal tissues at both mRNA and protein levels, but the 17 kDa FHIT was lower in tumors (P<0.05), this being confirmed immunohistochemically. There was a negative correlation between FHIT expression and histological grade of bladder transitional cell carcinoma (P<0.05), but no clear relationship with clinical stage or relapse (P>0.05). Overexpression of FHIT could induce apoptosis in bladder carcinoma 5637 cells, which could be enhanced by adding adriamycin (ADR). These findings suggest important roles of FHIT in bladder cancer development and provide support for the feasibility of FHIT-based gene therapy.     

细胞凋亡与子宫颈癌的发生

目的 探讨细胞凋亡与子宫颈癌发生、发展的关系。方法 １９０例手术切除标本中,正常宫颈鳞状上皮（ＮＥ）４１例;上皮内瘤样病变７８例,其中重度非典型增生（ＳＤ）４１例,原位癌（ＣＩＳ）３７例;早期侵袭癌（ＭＩＣ）３１例;大细胞非角化型浸润癌（ＩＣ）４０例。凋亡细胞检出用ＴＤＴ－ｍｅｄｉａｔｅｄ ｄＵＴＰｂｉｏｔｉｎ ｎｉｃｋ ｅｎｄ ｌａｂｅｌｉｎｇ（ＴＵＮＥＬ）方法,增生细胞核抗原（ＰＣＮＡ）、ｐ５３、ｂｃｌ－２基因蛋白表达采用免疫组化ＡＢＣ染色方法。结果 （１）在ＮＦ组,凋亡细胞分布在表层细胞,增生细胞却局限于深层细胞;在宫颈肿瘤性病变组织中,二者均毫无规律地散在于病灶中。（２）ＴＵＮＥＬ标识率伴随病变进展而降低,尤其从ＮＥ到ＣＩＳ组显著地减少（Ｐ〈０．０１）,而ＰＣＮＡ标识率却伴随病变进展呈进行性增加（Ｐ〈０     

同源结构域相互作用蛋白激酶2在宫颈癌中的表达及其与人乳头瘤病毒感染和细胞凋亡的关系

目的 探讨宫颈癌中同源结构域相互作用蛋白激酶2(HIPK2)的表达及其与人乳头瘤病毒(HPV)感染和细胞凋亡的关系.方法 取50例宫颈癌组织和15例正常宫颈组织,采用免疫组化法测定HIPK2和HPV的表达,采用DNA原位末端标记(TUNEL)技术检测了细胞凋亡情况.结果 15例正常宫颈组织中,HIPK2、HPV和PCNA阳性表达者分别有1、3和4例,而50例宫颈癌组织中分别有44、39和45例,官颈癌组织HIPK2、HPV和PCNA的表达明显高于正常官颈组织(均P<0.05).宫颈癌组凋亡指数(AJ)为(1.6±0.7)%,正常宫颈组AI为(5.7±0.2)%,差异有统计学意义(P<0.01).在宫颈癌组织中,HIPK2表达与HPV表达呈正相关(r=0.467,P=0.0006),与AI呈负相关(r=-0.370,P=0.0083).结论 在宫颈癌中,HIPK2的表达与HPV感染和细胞凋亡密切相关,可能在宫颈癌发生、发展中起重要作用.     

薏苡仁酯诱导人宫颈癌HeLa细胞凋亡的实验研究

目的　探讨薏苡仁酯诱导人宫颈癌HeLa细胞凋亡的作用机制。方法　应用形态学方法 ,流式细胞术 (FACS) ,DNA凝胶电泳等方法检测细胞凋亡的发生 ,应用RT PCR检测凋亡相关基因Fas与FasL的变化。结果　薏苡仁酯对人宫颈癌HeLa细胞的生长有明显的抑制作用 ,并诱导肿瘤细胞发生凋亡。凋亡细胞表现为细胞固缩 ,核染色质碎裂 ,DNA凝胶电泳显示清晰的DNA梯形条带 ,FACS检测到凋亡率最高为 13%。AnnexinV标记的方法检测凋亡时发现 ,坏死与凋亡共存。在薏苡仁酯诱导人宫颈癌HeLa细胞凋亡过程中 ,凋亡相关基因Fas转录水平比用药前增强 ,而FasL转录水平减低。结论　除了坏死 ,凋亡也为薏苡仁酯抑癌的机制之一。薏苡仁酯诱导人宫颈癌HeLa细胞凋亡可能与Fas基因与FasL基因表达有关。     

Prognostic implication of apoptosis and angiogenesis in cervical uteri cancer

Purpose: A retrospective study was performed to investigate the relationship between spontaneous apoptosis and angiogenesis uterine cervix squamous cell carcinoma patients. The prognostic value of each (and both) of these biologic parameters was also tested.

Methods and Materials: The pathologic materials of 40 cervical uteri squamous cell carcinoma patients were examined and immunohistochemically stained to determine the tumor angiogenesis (tumor microvascular score), using factor VIII-related antigen, and their tumor apoptotic index (AI), using the TdT-mediated dUTP nick end-labeling (TUNEL) method. Three patients were Stage I, 18 were Stage II, 15 were Stage III, and 4 were Stage IV (FIGO classification). All patients were treated with radical radiotherapy and all had follow-up for more than 2 years.

Results: The mean AI was 15.1 ± 12.8, with a median of 8.3. The mean tumor microvascular score was 3 9.7 ± 14.4, with a median of 3 8. The patients’ age and tumor grade did not seem to significantly affect the prognosis. On the other hand, AI and angiogenesis (tumor microvascular score) were of high prognostic significance. The 3-year disease-free survival (DFS) rate for the patients having AI above the median was 78% (confidence interval [CI] 69–87%), compared to 32% (CI 22–42%) for those having AI below the median. The DFS was 18% (CI 9–27%) for patients having an angiogenesis score above the median, while it was 86% (CI 78–94%) for those patients having a score below the median.

Conclusion: Determination of both tumor microvascular score and AI can identify patients with the best prognosis of 100% DFS (with low angiogenesis score and high AI). Women with a high score and low AI had the worst prognosis (DFS = 3%, CI 1–5%). Moreover, high AI can compensate partially for the aggressive behavior of tumors showing a high rate of angiogenesis.     

细胞增殖和凋亡在宫颈癌放疗中的预后价值

目的　研究增殖和凋亡在放射治疗宫颈癌中的预后价值。方法　回顾性分析了４０ 例放疗未控和根据临床病理因素与之配对的４０ 例放疗治愈的ⅡＢ～ⅢＢ 期宫颈鳞癌患者的细胞增殖和凋亡情况。以免疫组化ＡＢＣ法检测增殖细胞核抗原（ｐｒｏｌｉｆｅｒａｔｉｎｇ ｃｅｌｌｎｕｃｌｅａｒａｎｔｉｇｅｎ,ＰＣＮＡ） ,凋亡细胞用末端转移酶（ＴｄＴ） 介导的脱氧核苷酸切口及末端标记法（ＴｄＴｍｅｄｉａｔｅｄ ｂｉｏｔｉｎｄＵＴＰｎｉｃｋ ｅｎｄ ｌａｂｅｌｉｎｇ,ＴＵＮＥＬ）进行检测。结果　放疗治愈组的ＰＣＮＡ为５．３８ ±３．２１ ,未控组为７ ．５０ ±３．１６（ Ｐ＜ ０ ．０１） ;治愈组每１０ 个高倍视野下的有丝分裂细胞数为６．３３±５．１５,未控组为１１ ．３３ ±７．５０（ Ｐ＜ ０ ．００１） ;治愈组每１０ 个高倍视野下的凋亡细胞数为２０．９０±８．１９,未控组为２７ ．１３±１７ ．２８（ Ｐ＜ ０．０５）;凋亡细胞数与分裂细胞数之比值（Ａ／Ｍ） 治愈组为４ ．９７ ±３．３１,未控组为３．３６±２．８３（ Ｐ＜ ０ ．０５） 。结论　ＰＣＮＡ、凋亡细胞数以及Ａ／Ｍ 可作为预测放射治疗宫颈癌预后的新指标     

细胞凋亡和P53、PCNA表达在宫颈癌的研究

目的 :探讨细胞凋亡、P5 3蛋白和PCNA表达与宫颈癌发病的关系及与其生物学行为的关系。方法 :利用流式细胞仪PI法 ,测定正常宫颈组织 18例、宫颈上皮内瘤变 (CIN) 18例和宫颈癌 2 3例细胞凋亡指数 (AI) ,采有SP免疫组织化学染色方法检测各组宫颈上皮组织中P5 3蛋白和PCNA表达。结果 :正常宫颈组织AI值明显低于CIN组和宫颈癌组 (P <0 0 1) ,而宫颈癌组AI值明显低于CIN组 (P <0 0 5 )。突变P5 3蛋白和PCNA表达随宫颈各级病变的进展逐渐升高 ,二者在正常组织、CIN、宫颈癌三组中阳性表达率分别为 5 6 %、16 7%、4 7 8%和 5 6 %、6 1 2 %、78 3%。P5 3蛋白表达与宫颈癌组织分化级别、淋巴结转移无关 (P >0 0 5 ) ,而与宫颈癌临床分期有相关性 ;PCNA与宫颈癌临床期别、淋巴结转移无关 (P >0 0 5 ) ,而与宫颈癌组织分化级别有相关性 (P <0 0 1)。结论 :细胞凋亡和增殖的失衡在宫颈癌发生、发展过程中具有重要作用 ,野生型P5 3基因突变可能是细胞凋亡受抑的一个重要因素 ,P5 3及PCNA是判断宫颈癌的恶性程度和预后很重要的分子生物学指标。     

基于槲皮素标记的金属有机框架放疗联合阿霉素诱导宫颈癌HeLa细胞凋亡的研究

目的探讨基于槲皮素(Quercetin,QU;3,3′,4′,5,7-五羟基黄酮)标记的金属有机框架(Zr metal organic frameworks,Zr-MOF)放疗(Radiation therapy,RT)联合阿霉素(Doxorubicin,DOX)对宫颈癌HeLa细胞增殖和凋亡的影响。方法将宫颈癌HeLa细胞分为对照组、RT组、阿霉素处理组(Zr-MOF-DOX+RT)、QU处理组(Zr-MOF-QU+RT)及联合处理组(Zr-MOF-QU-DOX+RT);采用细胞克隆形成法检测各处理组HeLa细胞的增殖活性;蛋白印迹法及免疫荧光法检测各组细胞凋亡蛋白Caspase-3及缺氧诱导因子1α(Hypoxia inducible factor-1α,HIF-1α)的表达水平。结果联合处理组细胞的增殖能力明显低于其他各组,差异具有统计学意义(P<0.05);联合处理组HIF-1α蛋白表达量明显低于其他各组(P<0.05),联合处理组Caspase-3蛋白的表达含量明显高于其他各组(P<0.05)。结论基于槲皮素标记的金属有机框架放疗联合阿霉素对HeLa细胞的抑...     

棕榈酸在体外通过促进凋亡作用抑制宫颈癌Hela细胞增殖的研究

目的 探讨体外棕榈酸(Palmitic acid,PA)抑制人宫颈癌HeLa细胞增殖、迁移、侵袭和诱导凋亡作用及其部分机制。方法 体外培养的宫颈癌HeLa细胞分为对照组(不加药)、PA处理组(分别加入PA 25、50、100μg/mL处理),CCK-8法检测各组HeLa细胞增殖情况,Transwell试验检测细胞的迁移和侵袭能力,qRT-PCR检测不同浓度PA处理后细胞凋亡相关基因Bcl-2、Bax及Cleaved-caspase-3的表达,PA处理后的HaLa细胞用膜联蛋白V/碘化丙啶双标,随后用流式细胞仪检测其凋亡情况。结果 与对照组比较,PA处理HeLa细胞后增殖抑制率逐渐增高(P＜0.05);PA处理后,HaLa细胞的迁移与侵袭能力显著下降(P＜0.05);同时,PA处理HeLa细胞后,随着PA浓度增高,Bcl-2基因表达逐渐降低,而Bax和Cleaved-caspase-3基因表达逐渐增强与流式细胞仪检测结果相符合,HeLa细胞的凋亡率随着PA浓度增高逐渐增高(P＜0.05)。结论 PA体外可抑制HeLa细胞增殖,减少其迁移与侵袭水平,并诱导其凋亡,其机制可能与调节HeLa细胞Bcl-2家族有关。     

Candida and dysbacteriosis: A cytologic,population‐based study of 100,605 asymptomatic women concerning cervical carcinogenesis

BACKGROUND.

The objective of this study was to investigate whether the presence of vaginal Candida or dysbacteriosis predisposes women to an increased susceptibility for (pre)neoplasia over time.

METHODS.

A retrospective, longitudinal, cohort study was performed and was conducted in a population of 100,605 women, each of whom had 2 smears taken over a period of 12 years as part of the Dutch Cervical Screening Program. From these women, a cohort of 1439 women with Candida and a cohort of 5302 women with dysbacteriosis were selected as 2 separate study groups. The control cohort consisted of women who had completely normal cervical smears (n = 87,903 women). These groups were followed retrospectively over time. The odds ratios (OR) for squamous abnormalities in the follow‐up smear for the women in these 3 cohorts were established.

RESULTS.

The dysbacteriotic cohort was significantly more likely to have low‐grade squamous intraepithelial lesions (LSIL) and high‐grade squamous intraepithelial lesions (HSIL+) in their follow‐up smear (OR, 1.85; 95% confidence interval [95% CI], 1.28–2.67 and OR, 2.00; 95% CI, 1.31–3.05, respectively) compared with women in the control group. In contrast, the Candida cohort had no significantly increased or decreased risk of developing SIL. The equivocal diagnosis ‘atypical squamous cells of undetermined significance’ was rendered significantly more often in the follow‐up smear of both study cohorts (Candida cohort: OR, 1.42; 95% CI, 1.03–1.95; dysbacteriotic cohort: OR, 1.44; 95% CI, 1.22–1.71).

CONCLUSIONS.

The results from this study indicated that the presence of Candida vaginalis was not associated with an increased risk for SIL over time. In contrast, women with dysbacteriosis had a significantly increased risk of developing (pre)neoplastic changes. These findings should be taken into account in further research concerning predisposing factors for cervical carcinogenesis. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.     

p53/bcl-2与放疗诱导的宫颈癌细胞凋亡关系的研究

目的探讨宫颈癌放疗过程中,放疗诱导的细胞凋亡与p53、bcl-2的相关性.方法选择未经治疗的宫颈癌病人20例为实验对象,搜集分割放疗前后宫颈癌组织标本,用TDT-mediated dUTP-biotin nick end labeling(TUNEL)方法检测凋亡细胞;采用单克隆抗体免疫组化ABC法检测细胞凋亡相关基因p53、bcl-2的蛋白表达水平.结果(1)在宫颈癌放疗前后,细胞凋亡阳性率和平均凋亡指数分别为25%和0.11%、75%和2.8%,放疗前后有显著差异(P＜0.001);(2)放疗后p53蛋白表达显著减少,bcl-2蛋白无显著变化;(3)放疗前后,p53基因的表达与细胞凋亡呈有意义的相关性变化.结论放射治疗诱导了宫颈癌细胞凋亡的发生,并与凋亡调节基因p53及其表达呈间接有关.     

Proteomic analysis of ursolic acid-induced apoptosis in cervical carcinoma cells

Proteomic analyses can efficiently detect the variation of protein in high throughput screening. Using 2DE/MALDI-TOF-MS and SELDI-TOF-MS, we tried to search several cellular proteins that are responsive to ursolic acid (UA) in HeLa cervical carcinoma cells. Compared to control, UA-treated HeLa cells unfolded 25 proteins in significant changes by 2DE/MALDI-TOF-MS, most of which were involved in apoptosis. SELDI-TOF-MS with two types of protein chips profiled and analyzed proteomic features after administration of UA. Interestingly, eight polypeptide peaks can be detected. Further identification and characterization of these proteins may build the molecular basis of UA-induced apoptosis and provide insight into the anti-proliferative mechanism in cervical carcinoma cells.     

微核及凋亡技术预测宫颈癌细胞放射敏感性研究

目的:探讨微核及凋亡检测技术判断宫颈癌细胞放射敏感性的价值。方法:运用集落形成法、流式细胞术、CB微核法,分别检测3株宫颈癌细胞株(HeLa、SiHa、RJC)经X射线照射后细胞存活率、凋亡率及微核率的变化。结果:3株细胞接受0~8Gy射线照射后的微核率与照射剂量存在剂量-效应关系,其中HeLa细胞的微核率与照射剂量呈显著线形关系(P<0·05);照射后3株细胞的凋亡与照射剂量呈正相关(P<0·01);照射后3株细胞存活率与MN率成负相关(P<0·01)。结论:3株宫颈癌细胞的体外实验证明,微核及凋亡两项指标均能反映宫颈癌细胞的放射敏感性,但同时检测微核及凋亡是否可进一步提高预测准确性还有待进一步研究。     

Cyclooxygenase-2 impairs treatment effects of radiotherapy for cervical cancer by inhibition of radiation-induced apoptosis

PURPOSE: Cyclooxygenase-2 (COX-2) plays a pivotal role in regulation of radiation-induced apoptosis. The aim of this study was to analyze the relationship between COX-2 expression and postradiotherapy outcomes of patients with cervical cancer. METHODS AND MATERIALS: Biopsy specimens from 47 consecutive patients who had undergone definitive radiotherapy alone or radiotherapy combined with chemotherapy between October 2002 and November 2004 were investigated. RESULTS: The COX-2 expression rate of the pretreatment samples was 46.1% +/- 21.0%, and the apoptotic index (AI) 1 week after start of radiotherapy was 2.1% +/- 0.9%. There was a significant negative correlation between the pretreatment COX-2 expression and the AI during radiotherapy (r = -0.52, p = 0.0002). Complete response rates were 59% for COX-2-positive patients compared with 80% for COX-2-negative patients (p = 0.12). The 2-year local control rate for COX-2-positive patients was 71.3%, whereas the corresponding rate for COX-2-negative patients was 96.0% (p = 0.06). CONCLUSIONS: To the best of our knowledge, this is the first report to prove clinically that COX-2 can make cervical squamous cell carcinomas more refractory to radiotherapy by inhibition of radiation-induced apoptosis. Furthermore, expression of COX-2 may be a good indicator to predict local tumor control after radiotherapy. Although long-term results are ultimately needed, the combination therapy of radiotherapy with use of a COX-2 inhibitor could yield improved outcomes for patients with COX-2 expressing cervical cancer.     

Induction of apoptosis and manganese superoxide dismutase gene by photodynamic therapy in cervical carcinoma cell lines

Background. Photodynamic therapy (PDT) is a cancer treatment modality in which systemic administration of a tumor-localizing photosensitizer is followed by irradiation of the tumor with visible light. Although PDT is undergoing clinical trials for various cancers, the mechanisms of its action are not fully understood. To investigate the mechanism of cell death by PDT, we performed in-vitro PDT, using Photofrin II as a photosensitizer, in two human cervical carcinoma cell lines, HeLa and CaSki. Methods. Cells were incubated with Photofrin II for 24 h, followed by illumination, using a YAG-OPO laser. Cell survivability after PDT was evaluated by an MTT assay. Cytotoxicity was assayed by measuring the release of lactate dehydrogenase (LDH) into the supernatant. DNA of the PDT-treated cells was electrophoresed in an agarose gel to determine fragmentation. In situ detection of apoptosis in the PDT-treated cells was performed by identification of the 3′-OH ends of DNA. In addition, induction of manganese superoxide dismutase mRNA (MnSOD) was analyzed in the PDT-treated cells. Results. The CaSki cells were more sensitive to this PDT treatment than were the HeLa cells. DNA fragmentation was observed with less than 5 μg/ml of Photofrin II in both cell lines, whereas PDT-induced cell membrane destruction, determined by LDH release, was observed only at 10 μg/ml. The MnSOD mRNA was induced in the HeLa cells in the early hours after PDT with a non-lethal dose of Photofrin II, but was reduced with a high dose, whereas the CaSki cells did not show any induction of the MnSOD gene by PDT. Conclusion. The present results suggest that PDT induces cell death by a mechanism involving membrane destruction and apoptosis. Differences in cell susceptibilities to PDT may depend upon a protective mechanism, such as MnSOD gene induction. Received: August 5, 1999 / Accepted: December 10, 1999     

p73 protein expression correlates with radiation-induced apoptosis in the lack of p53 response to radiation therapy for cervical cancer

PURPOSE: p73 belongs to the p53 tumor suppressor family of genes and can inhibit cell growth in a p53-like manner by inducing apoptosis or cell cycle arrest. Here, we investigated whether p73 could compensate for impaired p53 function in apoptosis induced by radiation therapy (RT) for cervical cancer. METHODS AND MATERIALS: Sixty-eight patients with squamous cell carcinoma of the cervix who received definitive RT combined with (n=37) or without (n=31) cisplatin were investigated. Biopsy specimens were excised from the cervical tumor before RT and after 9 Gy. RESULTS: Mean apoptosis index (AI) was 0.93% before RT and 1.97% after 9 Gy with a significant increase (p<0.001). For all patients, there was a significant correlation between p73 expression positivity after 9 Gy and AI ratio (AI after 9 Gy/AI before RT) (p=0.021). Forty-one patients were regarded as the p53-responding group according to the expression of p53 after 9 Gy, whereas the remaining 27 patients were regarded as the p53-nonresponding group. A significant correlation between p73 expression after 9 Gy and AI ratio was observed in the p53-non-responding group (p<0.001) but not in the p53-responding group (p=0.940). CONCLUSION: Our results suggest that p73 plays an important role in compensating for the lack of p53 function in radiation-induced apoptosis of cervical cancer.     

伊立替康增敏对宫颈癌放疗中细胞凋亡和增殖及VEGF表达的影响

目的探讨伊立替康增敏对局部晚期宫颈癌放疗前、放疗中癌组织的细胞增殖、凋亡及VEGF的影响。方法41例局部中晚期宫颈癌患者(Ⅱb-Ⅳa期)随机分成两组,增敏组(20例)常规放疗 伊立替康,伊立替康40 mg/m2,放疗第一天开始使用,在放疗后1 h内给予,每周1次,共用5周;对照组(21例)常规放疗。每个病例在放疗前及放疗(10 Gy)后的24 h各取材1次。原位凋亡法检测细胞凋亡指数(A-LI),免疫组化方法检测宫颈癌组织的增殖细胞核抗原(PCNA)、血管内皮生长因子(VEGF)的表达,计算宫颈局部肿瘤消退50%所需时间(T50)。结果增敏组治疗中及治疗诱导的A-LI较对照组明显增加(P=0.004,P=0.034);PCNA的表达增敏组较对照组降低更明显(P=0.037);VEGF的表达增敏组和对照组均较治疗前上升,但两者比较差异无显著性(P=0.425)。增敏组T50明显短于对照组(P<0.05)。治疗诱导的A-LI与T50呈负相关。结论伊立替康增敏可抑制放疗早期宫颈癌细胞增殖,促进放疗诱导的癌细胞凋亡,使宫颈肿瘤消退50%时间缩短,肿瘤体积缩小更快。     

Targeting pro-apoptotic trail receptors sensitizes HeLa cervical cancer cells to irradiation-induced apoptosis

PURPOSE: To investigate the potential of irradiation in combination with drugs targeting the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor (DR)4 and DR5 and their mechanism of action in a cervical cancer cell line. METHODS AND MATERIALS: Recombinant human TRAIL (rhTRAIL) and the agonistic antibodies against DR4 and DR5 were added to irradiated HeLa cells. The effect was evaluated with apoptosis and cytotoxicity assays and at the protein level. Membrane receptor expression was measured with flow cytometry. Small-interfering RNA against p53, DR4, and DR5 was used to investigate their function on the combined effect. RESULTS: rhTRAIL and the agonistic DR4 and DR5 antibodies strongly enhanced 10-Gy-induced apoptosis. This extra effect was 22%, 23%, and 29% for rhTRAIL, DR4, and DR5, respectively. Irradiation increased p53 expression and increased the membrane expression of DR5 and DR4. p53 suppression, as well as small-interfering RNA against DR5, resulted in a significant downregulation of DR5 membrane expression but did not affect apoptosis induced by irradiation and rhTRAIL. After small-interfering RNA against DR4, rhTRAIL-induced apoptosis and the additive effect of irradiation on rhTRAIL-induced apoptosis were abrogated, implicating an important role for DR4 in apoptosis induced through irradiation in combination with rhTRAIL. CONCLUSION: Irradiation-induced apoptosis is strongly enhanced by targeting the pro-apoptotic TRAIL receptors DR4 or DR5. Irradiation results in a p53-dependent increase in DR5 membrane expression. The sensitizing effect of rhTRAIL on irradiation in the HeLa cell line is, however especially mediated through the DR4 receptor.     

pRb-expressing adenovirus Ad5-Rb attenuates the p53-induced apoptosis in cervical cancer cell lines

The retinoblastoma protein (pRb), the gene product of the first reported tumour suppressor gene, is functionally inactivated by the E7 protein of high-risk human papillomavirus (HPV) found in most human cervical cancers. We have, in this study, constructed an adenoviral vector expressing wild-type pRb (Ad5-Rb) and used the constructed Ad5-Rb to transfect the osteosarcoma cell line Saos-2, and three cervical cancer cell lines HeLa, SiHa and C-33A. Our results showed that pRb caused G1 arrest in Saos-2 cells after transfection with Ad5-Rb. The number of colonies formed by the Ad5-Rb-transfected Saos-2 cells in soft agar was also found to be significantly lower (P<0.05) than those transfected with the adenoviral control expressing Escherichia coli β-galactosidase (Ad5-LacZ). The transfection of Ad5-Rb caused an increase in the population of SiHa and C-33A cells in the G1 phase from 53.0 and 52.9% to 72.4 and 64.3%, respectively, but not in the HeLa cells. However, Ad5-Rb did not show any inhibitory effect on the growth of SiHa, HeLa and C-33A cells, and inhibition of colony formation in soft agar was not observed either. In contrast, flow cytometric analysis showed that Ad5-p53, a p53-expressing adenovirus, induced apoptosis, i.e. the appearance of sub-G1 peak, in all three tested cervical cancer cell lines. Nevertheless, the Ad5-p53-induced apoptosis was partially inhibited when Ad5-Rb was added simultaneously. These findings suggested that pRb may not be a good candidate for cervical cancer gene therapy. Our data also showed that the use of full-length pRb in combination with TP53 might not be a suitable strategy for cancer gene therapy.     

Methyl jasmonate induces cell death with mixed characteristics of apoptosis and necrosis in cervical cancer cells

In the present study the effectiveness of methyl jasmonate (MJ) against cervical cancer cell lines was investigated. We show that MJ is cytotoxic to a range of cervical cancer lines including SiHa, CaSki and HeLa that carry human papillomavirus (HPV) DNA and wild type p53, and C33A that is negative for HPV and contains mutant p53. Primary human foreskin keratinocytes were almost resistant to the drug. Cytotoxicity of MJ was dose and time dependent, and associated mainly with the induction of cell death and to a less extent with inhibition of cell growth. Cell death induced by MJ displayed features characteristic to both apoptosis and necrosis, and was associated with different changes in the levels of p53, p21, bcl-2 and bax in the various cervical cancer lines. In conclusion, MJ a novel anticancer agent, acts via multiple pathways to induce death of cervical cancer cells, thus making it a promising candidate for treatment of cervical cancer.