Recombinant, refolded tetrameric p53 and gonadotropin-releasing hormone-p53 slow proliferation and induce apoptosis in p53-deficient cancer cells

The p53 tumor suppressor is mutated in over 50% of human cancers. Mutations resulting in amino acid changes within p53 result in a loss of activity and consequent changes in expression of genes that regulate DNA repair and cell cycle progression. Replacement of p53 using protein therapy would restore p53 function in p53-deficient tumor cells, with a consequence of tumor cell death and tumor regression. p53 functions in a tetrameric form in vivo. Here, we refolded a wild-type, full-length p53 from inclusion bodies expressed in Escherichia coli as a stable tetramer. The tetrameric p53 binds to p53-specific DNA and, when transformed into a p53-deficient cancer cell line, induced apoptosis of the transformed cells. Next, using the same expression and refolding technology, we produced a stable tetramer of recombinant gonadotropin-releasing hormone-p53 fusion protein (GnRH-p53), which traverses the plasma membrane, slows proliferation, and induces apoptosis in p53-deficient, GnRH-receptor-expressing cancer cell lines. In addition, we showed a time-dependent binding and internalization of GnRH-p53 to a receptor-expressing cell line. We conclude that the GnRH-p53 fusion strategy may provide a basis for constructing an effective cancer therapeutic for patients with tumors in GnRH-receptor-positive tissue types.     

基因芯片用于活化支气管上皮细胞基因表达的研究

目的探讨基因芯片筛选肿瘤坏死因子(TNF)-α活化后支气管上皮细胞基因表达的变化。方法提取支气管上皮细胞系(BEAS-2B细胞)总RNA,用基因芯片检测正常培养和经TNF-α活化的BEAS-2B细胞基因表达,对上调表达的基因用逆转录聚合酶链反应(RT-PCR)确证,用流式细胞微珠方法(CBA)检测TNF-α活化的BEAS-2B细胞培养液中相关细胞因子浓度。结果TNF-α活化后BEAS-2B细胞中细胞间黏附分子(ICAM)-1、白细胞介素(IL)-8、单核细胞趋化蛋白(MCP)-1、TNF-α、IL-6基因表达显著上调(分别上调6·5、8·2、3·1、4·9和3·5倍),表达上调的基因用RT-PCR确证结果基本一致。TNF-α活化后BEAS-2B细胞培养液中细胞因子的分泌(BEAS-2B细胞培养过程中有、无TNF-α存在,IL-6、IL-8和MCP-1的分泌分别为:(117·83±18·20)ng/L和(1771·33±312·67)ng/L,P<0·001;(277·97±50·76)ng/L和(7579·20±797·15)ng/L,P<0·001;(741·53±129·91)ng/L和(12228·57±1897·58)ng/L,P<0·001),与相应基因的表达一致。结论用基因芯片方法筛选活化后支气管上皮细胞基因表达对研究支气管上皮在气道性疾病中的作用具有重要意义。     

支气管上皮增生病变FHIT和p53基因检测

目的检测和分析FHIT基因杂合性缺失/微卫星不稳定（LOH/MI）和p53突变在肺癌和肺炎性病变（简称肺炎）的支气管上皮增生病变中是否存在差异。方法采用PCR银染技术结合二核苷酸（CA）n重复序列及PCR-SSCP-DNA测序法分别检测FHITLOH/MI和p53突变。采用免疫组化法检测FHIT和p53表达。结果FHITLOH/MI在肺癌组的鳞状上皮化生病变和轻-中度非典型增生病变分别为53.8%和70%,均明显大于肺炎性病变组的相应增生病变12.5%和18.2%,差异显著（P〈0.05）。p53突变率在肺癌组和肺炎组的各级增生病变比较差异不显著（P〉0.05）。结论FHITLOH/MI在肺癌组支气管上皮各级增生病变明显高于肺炎组,为其作为判断癌前病变的检测指标提供了实验依据。在肺癌前病变中FHIT基因LOH/MI同p53基因突变无关,是发生频率更高、更早的基因事件。     

Failure of wild-type p53 gene therapy in human cancer cells expressing a mutant p53 protein.

The introduction of exogenous wild-type p53 into human cancer cells bearing p53 mutation does not necessarily result in inhibition of tumor growth. We have demonstrated this in MDA-MB468 breast cancer cells which are hemizygous for p53 mutation and also in KM12SM colorectal carcinoma cells which are heterozygous for p53 mutation. The wtp53 transfectants decreased three- to four-fold the number of colonies compared with controls. Most wtp53-expressing cells died by apoptosis at early passages, but some cells were able to form colonies and their proliferation rate was similar to control transfectants. This reversion was observed in three of the six MDA-MB-468 clones selected. When MDA-wtp53 transfectants were implanted orthotopically in nude mice only one clone showed prolonged tumor latency. No differences were found in either tumor proliferation or apoptosis in tumors. Integration and expression of exogenous wtp53 was assessed in early and late passages in vitro, and in tumors growing in vivo. Consistently, we found mutations in the exogenous wtp53 gene of MDA-MB468 transfectants. Excision of the exogenous gene was an alternative to abrogate the wtp53 function that was extremely efficient in KM12 cells, although they maintained resistance to geneticin. These results were corroborated by the functional assay in yeast. In conclusion, wtp53 is inactivated in these cancer cells by different mechanisms. The presence of mutated p53 may confer genome instability and mutator ability, which allows cells to escape the effects of the exogenous wtp53 and contributes to the failure of wtp53 gene therapy.     

Lonidamine induces apoptosis in drug-resistant cells independently of the p53 gene.

Lonidamine, a dichlorinated derivative of indazole-3-carboxylic acid, was shown to play a significant role in reversing or overcoming multidrug resistance. Here, we show that exposure to 50 microg/ml of lonidamine induces apoptosis in adriamycin and nitrosourea-resistant cells (MCF-7 ADR(r) human breast cancer cell line, and LB9 glioblastoma multiform cell line), as demonstrated by sub-G1 peaks in DNA content histograms, condensation of nuclear chromatin, and internucleosomal DNA fragmentation. Moreover, we find that apoptosis is preceded by accumulation of the cells in the G0/G1 phase of the cell cycle. Interestingly, lonidamine fails to activate the apoptotic program in the corresponding sensitive parental cell lines (ADR-sensitive MCF-7 WT, and nitrosourea-sensitive LI cells) even after long exposure times. The evaluation of bcl-2 protein expression suggests that this different effect of lonidamine treatment in drug-resistant and -sensitive cell lines might not simply be due to dissimilar expression levels of bcl-2 protein. To determine whether the lonidamine-induced apoptosis is mediated by p53 protein, we used cells lacking endogenous p53 and overexpressing either wild-type p53 or dominant-negative p53 mutant. We find that apoptosis by lonidamine is independent of the p53 gene.     

A protumorigenic secretory pathway activated by p53 deficiency in lung adenocarcinoma

Therapeutic strategies designed to target TP53-deficient cancer cells remain elusive. Here, we showed that TP53 loss initiated a pharmacologically actionable secretory process that drove lung adenocarcinoma (LUAD) progression. Molecular, biochemical, and cell biological studies showed that TP53 loss increased the expression of Golgi reassembly and stacking protein 55 kDa (G55), a Golgi stacking protein that maintains Golgi organelle integrity and is part of a GOLGIN45 (G45)–myosin IIA–containing protein complex that activates secretory vesicle biogenesis in the Golgi. TP53 loss activated G55-dependent secretion by relieving G55 and myosin IIA from miR-34a–dependent silencing. G55-dependent secreted proteins enhanced the proliferative and invasive activities of TP53-deficient LUAD cells and promoted angiogenesis and CD8⁺ T cell exhaustion in the tumor microenvironment. A small molecule that blocks G55-G45 interactions impaired secretion and reduced TP53-deficient LUAD growth and metastasis. These results identified a targetable secretory vulnerability in TP53-deficient LUAD cells.     

The role of natural killer cells in adenovirus-mediated p53 gene therapy

Adenovirus-mediated gene therapy is a promising new approach for treatment of ovarian cancer. In animal models, complete elimination of cancer cells is often achieved, although the therapeutic gene has not been delivered to all these cells. This is referred to as a bystander effect, because tumor cells near those that receive the therapeutic gene are also eliminated. Several mechanisms have been proposed for the bystander effect, including intercellular communication within the tumor via gap junctions, apoptosis, antiangiogenesis, cytokines or other soluble mediators, and immunological mechanisms. There are two well-documented antitumor effector cell populations in athymic nude mice: macrophages and natural killer (NK) cells. We hypothesize that peritoneal populations of NK cells in nude mice treated with adenoviruses are involved in the observed bystander effect in this in vivo model. We investigated the role of NK cells as immunological mediators for the bystander effect using the p53 tumor suppressor as the therapeutic anticancer gene. Most ovarian cancer cell lines tested were sensitive to lysis by NK cells, although different ovarian cancer cell lines exhibited different sensitivities to NK cell-mediated lysis. To determine the importance of NK cells in the overall efficacy and in the bystander effect of gene therapy, NK cells were depleted in mice by administration of anti-NK1.1 monoclonal antibodies. To study the efficacy of NK depletion, C57BL/6 (nu/nu) mice were given injections i.v. by a single tail vein injection or i.p. with increasing doses of anti-NK1.1 IgG. All doses of anti-NK1.1 antibody, from 100-500 micrograms, essentially eliminated cytotoxic NK activity. To assess the duration of depletion after a single dose of anti-NK1.1 IgG, a time-course experiment was performed. NK 1.1 antibody was effective in completely depleting cytotoxic NK cell activity in the mice for up to 7 days, whether given as 500 micrograms (i.p.) or 200 micrograms (i.v.). Flow cytometric analysis performed on peritoneal cell populations confirmed depletion of NK cells by approximately 80%. Finally, a survival study was performed, in which animals were depleted of NK cells. In this experiment, NK cell-depleted mice were injected with anti-NK1.1 IgG, and control mice were mice were treated with normal saline. Two days later, all mice were inoculated with a lethal i.p. dose of NIH:OVCAR-3 ovarian cancer cells. After 3 days, the mice were divided into two treatment groups; one treatment group received three consecutive daily i.p. injections of Ad-CMV-p53 (SCH58500), and the second treatment group received three consecutive daily i.p. injections of control adenovirus construct, rAd-null. All of the NK cell-depleted animals, whether treated with rAd-null or with Ad-CMV-p53 (SCH58500) were dead of disease by 116 and 138 days, respectively, after initiation of adenovirus treatment, and no statistically significant difference in survival was observed (P = 0.349). A significant survival advantage was seen in control (NK-competent) mice treated with rAd-null (P = 0.04), although all were dead of disease by day 184. Importantly, control NK-competent mice treated with Ad-CMV-p53 (SCH58500) showed no tumor growth or ascites production, and all animals survived. These results indicate that immunological mechanisms involving natural killer cells play an important role in the bystander effect involving adenovirus-p53 gene therapy for ovarian cancer.     

结直肠癌p53基因点突变和蛋白表达的研究

目的了解中国人结直肠癌ｐ５３基因的突变谱，探讨聚合酶链反应－单链构象多态（ＰＣＲ－ＳＳＣＰ）银染技术用于研究结直肠癌中ｐ５３基因突变的可行性。方法应用ＰＣＲ－ＳＳＣＰ银染技术检测４１例结直肠癌ｐ５３基因突变，以ＡＢＣ免疫组织化学染色检测结直肠癌Ｐ５３蛋白的表达。结果３４％（１４／４１）的病例显示有ｐ５３基因突变，其中外显子５，６，７和８各有４，１，５和４例突变。２０例有Ｐ５３蛋白异常表达，阳性率为４９％。结论导致Ｐ５３蛋白异常堆积的ｐ５３基因突变是结直肠癌的一种常见的分子结构改变，可能在结直肠癌的发生和发展中起着重要的作用。ＰＣＲ－ＳＳＣＰ银染技术是一简便、快速、有效的检测基因点突变的方法     

An effective immunization and cancer treatment with activated dendritic cells transduced with full-length wild-type p53

P53-based immunization is an attractive approach to cancer immunotherapy due to the accumulation of p53 protein in tumor, but not in normal cells. However, it was not known whether immune response against self-protein (p53) could be generated in vivo. Mouse dendritic cells (DCs) were transduced with adenoviral construct containing murine full-length wild-type p53 (Ad-p53). Repeated immunizations with these cells protected 60% of mice against challenge with MethA sarcoma cells bearing point mutations in p53 gene. Activation of DCs via ligation of CD40 significantly improved the results of immunization: all mice were protected against MethA sarcoma. The treatment of MethA tumor-bearing mice with activated Ad-p53-transduced DCs showed complete tumor rejection in four out of six mice. The specificity of antitumor immune response was confirmed by CTL assay. The analysis of phenotype and function of DCs demonstrated that the effect of CD40 ligation on these cells was enhanced by their infection with Ad-p53. The level of neutralizing anti-adenovirus antibody was moderately elevated in these mice. No signs of autoimmune reaction were evident during detailed pathological evaluation of treated mice. These data demonstrate that activated Ad-p53-infected DCs are able to break tolerance to this protein and can be used in immunotherapy of cancer.     

Cycloheximide protects HepG2 cells from serum withdrawal-induced apoptosis by decreasing p53 and phosphorylated p53 levels

Cycloheximide (CHX), an inhibitor of protein synthesis, has been reported to prevent cell death in a wide variety of cell types and produced by different apoptotic stimuli. However, the mechanisms by which CHX protects cells from apoptosis are still unclear. In this study, we investigated whether p53 plays a role in the protection by CHX against serum withdrawal-induced apoptosis. Deprivation of serum from the culture medium causes apoptosis in HepG2 cells, and CHX dramatically protects cells from death. p53, p21, and Bax protein levels were elevated, and cell cycle arrest was produced after serum withdrawal. CHX abolished this elevation of p53, p21, and Bax as well as the cell cycle arrest induced by serum deprivation. The p53 inhibitor pifithrin-alpha protects HepG2 cells against apoptosis induced by serum withdrawal. HepG2 cells expressing a dominant negative form of mutant p53 and Hep3B cells lacking p53 were resistant to serum withdrawal-induced apoptosis. Lowering of p53 by small interfering RNA protects HepG2 cells from serum withdrawal-induced apoptosis. p53 phosphorylation was induced by serum withdrawal and other chemotherapeutic reagents such as actinomycin D, doxorubicin, and etoposide. CHX decreases the levels of phosphorylated p53 (pp53) even in the presence of a proteasome inhibitor, which maintains the total p53 levels, whereas it does not affect the dephosphorylation of pp53. These results suggest the possibility that kinases that phosphorylate p53 might be affected by CHX administration. In summary, CHX protects HepG2 cells from serum withdrawal-induced apoptosis through inhibiting the synthesis of p53 and the phosphorylation of p53.     

MiR-26b通过抑制p53基因表达增强胰腺癌细胞对吉西他滨抗药性

目的通过对miR-26b靶定p53促进胰腺癌细胞系PANC-1抗药性的研究,揭示胰腺癌细胞抗药机制,为临床治疗提供依据。方法 (1)构建p53的过表达和敲降质粒,以及含3′端非编码序列区(3′UTR)的荧光报告载体;(2)采用四甲基偶氮唑盐(MTT)实验研究在吉西他滨存在的条件下p53和miR-26b对PANC-1生长增殖的影响;(3)采用生物信息学、实时定量聚合酶链反应(PCR)试验、荧光报告载体和Western印迹试验确定miR-26b与p53的靶定关系;(4)采用挽救试验研究过表达p53对miR-26b促进细胞生长作用的影响。结果(1)MTT试验证实,在吉西他滨存在的条件下,过表达p53抑制胰腺癌细胞系PANC-1生长增殖,而敲降p53可以促进PANC-1生长和增殖;(2)生物信息学预测显示miR-26b靶定p53,实时定量PCR、荧光报告载体试验和Western印迹试验证实p53是miR-26b的靶基因,miR-26b通过靶定3′UTR抑制p53的转录和翻译;(3)MTT试验证实,在吉西他滨存在的条件下,过表达miR-26b促进PANC-1细胞系生长增殖,增强PANC-1细胞系对吉西他滨的抗药性;(4)挽救试验证实,同时过表达p53挽救miR-26b对PANC-1抗药的促进作用。结论 miR-26b通过靶定p53基因3′UTR抑制其表达,增强胰腺癌细胞系PANC-1对吉西他滨的抗药性。     

Pkd1 regulates immortalized proliferation of renal tubular epithelial cells through p53 induction and JNK activation

Autosomal dominant polycystic kidney disease (ADPKD) is the most common human monogenic genetic disorder and is characterized by progressive bilateral renal cysts and the development of renal insufficiency. The cystogenesis of ADPKD is believed to be a monoclonal proliferation of PKD-deficient (PKD(-/-)) renal tubular epithelial cells. To define the function of Pkd1, we generated chimeric mice by aggregation of Pkd1(-/-) ES cells and Pkd1(+/+) morulae from ROSA26 mice. As occurs in humans with ADPKD, these mice developed cysts in the kidney, liver, and pancreas. Surprisingly, the cyst epithelia of the kidney were composed of both Pkd1(-/-) and Pkd1(+/+) renal tubular epithelial cells in the early stages of cystogenesis. Pkd1(-/-) cyst epithelial cells changed in shape from cuboidal to flat and replaced Pkd1(+/+) cyst epithelial cells lost by JNK-mediated apoptosis in intermediate stages. In late-stage cysts, Pkd1(-/-) cells continued immortalized proliferation with downregulation of p53. These results provide a novel understanding of the cystogenesis of ADPKD patients. Furthermore, immortalized proliferation without induction of p53 was frequently observed in 3T3-type culture of mouse embryonic fibroblasts from Pkd1(-/-) mice. Thus, Pkd1 plays a role in preventing immortalized proliferation of renal tubular epithelial cells through the induction of p53 and activation of JNK.     

首次应用反转录病毒仅感染分裂细胞特性构建hTERT驱动野生型p53基因反转录病毒载体质粒

目的:选择只感染分裂细胞的鼠源性反转录病毒载体pLHCX作为载体,构建由hTERT启动子驱动目的基因表达的载体,实现靶向性表达.方法:实验于2005-09/2006-05在江西省分子医学重点实验室完成.①实验材料:含319 bp hTERT核心启动子的phTERT-luc质粒由军事科学院郑晓飞博士惠赠,反转录病毒载体质粒pLHCX由浙江大学朱永良教授惠赠,含1.8 kb wtp53基因的质粒pCMV-Neo-BamH-wtp53由第二军医大学朱明华教授惠赠,增强型绿色荧光蛋白报告质粒pEGFP-N2和pEGFP-C1由本室保存,对照反转录病毒质粒pLHCX-CMV-EGFP前期构建完成;端粒酶阳性人大肠癌细胞SW620、HT-29,人宫颈癌细胞Hela,人肺癌细胞A549和端粒酶阴性人胚肺成纤维细胞MRC-5由本室保存.②实验方法:利用定向克隆的方法分别构建由hTERT启动子驱动EGFP的质粒pLHCX-hTERT-EGFP和驱动wtp53表达的质粒pLHCX-hTERT-wtp53.以质粒pLHCX-hTERT-EGFP和课题组前期构建的质粒pLHCX-CMV-EGFP转染端粒酶阳性的人大肠癌细胞株SW620和HT-29、人宫颈癌细胞株Hela和人肺癌细胞株A549以及端粒酶阴性的正常人肺胚成纤维细胞MRC-5.③实验评估:通过流式细胞仪测定分析转染效率,证实pLHCX-hTERT-EGFP在不同细胞中的表达特异性.运用RT-PCR和Western Blot分别检测p53 mRNA和p53蛋白在p53突变的大肠癌细胞株SW620中表达.利用MTT检测质粒pLHCX-hTERT-wtp53对不同细胞的增殖抑制情况和流式细胞术检测不同细胞的凋亡情况.结果:①通过酶切证实重组质粒pLHCX-hTERT-EGFP和pLHCX-hTERT-wtp53构建成功,并通过将pLHCX-hTERT-EGFP转染SW620细胞观察到绿色荧光蛋白的表达,测序证实构建质粒中包含完整的wtp53片段.②流式细胞术检测结果证实质粒pLHCX-hTERT-EGFP处理后端粒酶阳性的SW620、Hela和A549内增强型绿色荧光蛋白表达强度明显强于端粒酶阴性的MRC-5(P < 0.05),而pLHCX-CMV-EGFP在端粒阳性和阴性的上述细胞中表达无明显差异(P > 0.05).③RT-PCR和Western Blot分别证实了p53mRNA和p53蛋白表达.④MTT检测到重组质粒对端粒酶阳性的大肠癌细胞有明显的增殖抑制作用,而对端粒酶阴性的MRC-5细胞生长无明显影响(P < 0.05).⑤流式细胞检测观察到重组质粒引起端粒酶阳性的大肠癌细胞凋亡要明显强于端粒酶阴性的MRC-5细胞(P < 0.05).结论:构建的反转录病毒载体质粒pLHCX-hTERT-EGFP在端粒酶阳性的肿瘤细胞中特异性表达;重组反转录病毒载体质粒pLHCX-hTERT-wtp53转染后对端粒酶阳性的大肠癌细胞有特异性的影响作用.     

Eradication of p53-mutated head and neck squamous cell carcinoma xenografts using nonviral p53 gene therapy and photochemical internalization.

Photochemical internalization (PCI) technology has been used for PEI-mediated p53 gene transfer in mice bearing head and neck squamous cell carcinoma (HNSCC) xenografts. Using luciferase as a reporter gene, PCI led to a 20-fold increase in transgene expression 48 h after transfection and sustained transgene expression for 7 days. Therefore, iterative p53 gene transfer was performed by means of a weekly single injection of PEIGlu4/p53 complexes alone or with PCI for 5 (group A) or 7 (group B) weeks. The efficiency of p53 gene therapy was evaluated by following tumor growth and expression of P53-related downstream proteins (P21, MDM2, Bcl2, Bax). Apoptosis induction was evidenced through caspase-3 activation and PARP cleavage. Using PCI, tumor growth inhibition was observed in all transfected animals. Further, successful tumor cure was achieved in 17% (group A) and 83% (group B) of animals. PCI-mediated p53 gene transfer led to higher P53 protein expression that was correlated with induction of Bax and P21 proapoptotic proteins, repression of Bcl2 as well as activation of caspase-3, and cleavage of PARP. The present study demonstrates that PCI enhances the in vivo efficiency of PEI-mediated p53 gene transfer and can be proposed for p53 gene therapy in HNSCC.     

Statins induce mammalian target of rapamycin (mTOR)-mediated inhibition of Akt signaling and sensitize p53-deficient cells to cytostatic drugs

Cholesterol-lowering statins have been shown to have anticancer effects in different models and sensitize human tumor cells to cytostatic drugs. We have investigated the effect of statins on Akt/protein kinase B signaling and the sensitizing effect of cytostatic drugs. It was found that insulin- and cytostatic drug-induced Akt phosphorylation and nuclear translocation was inhibited by pravastatin and atorvastatin in HepG2, A549, and H1299 cells in an mTOR-dependent manner. Statins also induced mTOR-dependent phosphorylation of insulin receptor substrate 1. In p53 wild-type cells (HepG2 and A549), pretreatment with statins did not sensitize cells to etoposide in concentrations which induced p53 stabilization. In line with our previous data, statins were found to attenuate the etoposide-induced p53 response. However, silencing p53 by RNA interference rescued the sensitizing effect. We also show that in a p53-deficient cell line (H1299), pretreatment with atorvastatin sensitized cells to etoposide, doxorubicin, and 5-fluorouracil and increased the level of apoptosis. Taken together, these data suggest that a mTOR-dependent, statin-induced inhibition of Akt phosphorylation and nuclear translocation sensitizes cells to cytostatic drugs. However, this effect can be counteracted in p53 competent cells by the ability of statins to destabilize p53.     

脉冲电场联合野生型p53基因诱导人宫颈癌Hela细胞凋亡

背景:在前期研究基础上,设想将基因电转染作为脉冲电场治疗恶性肿瘤的辅助方法。目的:探讨脉冲电场联合抑癌基因野生型p53基因诱导人宫颈癌hela细胞发生凋亡及相互作用。方法:采用空质粒及含有野生型p53的质粒转染Hela细胞得到Hela-vector、Hela-p53细胞,将Hela细胞、Hela-vector和Hela-p53细胞分别施加固定脉宽100μs、频率1Hz、脉冲数8个、电场强度为1500V/cm的脉冲电场处理。结果与结论:相同参数脉冲电场作用于各组细胞12h后,MTT结果显示Hela-p53组细胞吸光度明显低于Hela组(P<0.05);流式细胞仪及RT-PCR检测结果显示Hela-p53组的早期凋亡率和p53mRNA表达较Hela组明显增加;Westernbolt及激光共聚焦显微镜结果显示与Hela组比较,Hela-p53组细胞Bax蛋白表达明显上升,而Bcl-2蛋白则明显下降,Casepase-3相对荧光强度明显增强。表明野生型p53基因对宫颈癌Hela细胞生长有明显的抑制作用,野生型p53基因可以提高脉冲电场诱导宫颈癌Hela细胞凋亡的作用。