Detecting the polymorphism sites of p53 and Fas genes of Han population in Zhejiang province

BACKGROUND： It is of significance for single nucleotide polymorphisms （SNPs）, a difference of rank, which exists widely in biology, genetics and other fields. OBJECTIVE： To detect polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene of healthy people in Han nationality in Zhejiang province. DESIGN： Simple random sampling. SETTING： Department of Surgery of the 118 Hospital of Chinese PLA.PARTICIPANTS： A total of 80 healthy people in Han nationality were selected from hospitals in Zhejiang province from August 2005 to January 2006. There were 43 males and 37 females aged from 3 to 78 years with the mean age of 39.5 years, and all subjects were consent. DNA which was used in genetic analysis was selected from peripheral venous blood of all subjects and maintained at -20℃.METHODS： Polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene were detected with directly DNA sequencing technique. MAIN OUTCOME MEASURES ： Polymorphism sites in exon-4 of p53 gene, promotor of Fas gene and intron-7 of Fas gene of healthy people in Han nationality in Zhejiang province. RESULTS： A total of 80 samples were involved in the final analysis. SNPs sites were found at the 119^th base of exon-4 of p53 gene （the 72^nd codon of p53 gene）, the 670^th base of upper start codon in promotor of Fas gene （Fas-670）, and the 995^th base of intron-7 of Fas gene, especially SNPs in the 995^th base of intron-7 pf Fas gene, i.e. C→A transversion, was a new site.CONCLUSION ： One unknown SNPs site is discovered in intron-7 of Fas gene of people in Han nationality in Zhejiang province. This study also proves that the 72^nd codon exists in p53 gene and the -670 polymorphism site exists in promotor of Fas gene.

PROMOTION OF CHEMICAL CARCINOGENESIS AND P53 EXPRESSION BY REDUCTION OF SUPEROXIDE DISMUTASE ACTIVITY IN THE LUNG OF RAT IN V

In the present experiment,an inhibitor of superoxide dismutase(SOD),diethyldithiocarbamate(DETC),was used to decrease SOD activity for the observation of the relation between SOD activity and carcinogenesis and the expression of P53 protein in vivo.144 Wistar rats were used for the Present study.The results showed that the SOD activity reduction by DETC resulted markedly in the promotion of the carcinogenesis and the expression of P53 protein in the lung tissues,but the increase of SOD activity by the addition of plus SOD inhibited the pathological changes significantly.The frequency of the pathological lesions and Positive P53 expression are 36/42 and 8/42 in the animals without DETC and SOD:16/52 and 4/52 in the animals with SOD and 46/50 and 26/50 in the animals with DETC respectively.The results reported in this Paper suggest that:(1) the decrease of SOD activity enhanced the carcinogenesis induced by chemical carcinogen;(2) P53 gene may be associated with the process of tumorigenesis;and(3) at the same time the abnormal expression of P53 protein may be associated with the transition from premalignant lesions to carcinoma.

p53在乳腺癌中的表达及其临床意义

目的探讨p53蛋白在乳腺癌中的表达及其临床意义。方法收集该科收治的214例乳腺癌患者的临床病理资料,回顾性分析p53蛋白表达情况及其与临床病理特征的相关性。结果 p53蛋白阳性率为52.3%;p53阳性表达与患病年龄、病灶大小无相关性(P>0.05),与淋巴结转移状态、肿瘤组织学分级及分子分型呈正相关(r=0.396、0.309、0.167,P=0.000、0.000、0.014),与雌激素受体、孕激素受体的表达呈负相关(r=-0.561、-0.315,P=0.000、0.000),与人表皮生长因子受体2及Ki-67的表达呈正相关(r=0.374、0.153,P=0.000、0.026);三阴型与非三阴型中p53蛋白表达差异有统计学意义(P<0.05)。结论p53与乳腺癌生物学特性密切相关,检测乳腺癌中p53的表达可作为指导临床治疗和判断预后的参考指标。

rAd-p53联合放化疗治疗晚期头颈部鳞状细胞癌

p53基因是迄今为止发现与人类肿瘤相关性最高的基因，在头颈部癌中，p53基因在喉癌、上颌窦癌、唾液腺癌、鼻咽癌等中均可见到阳性表达，而以复制缺陷型重组腺病毒为载体的p53基因替代疗法作为一种肿瘤治疗的新方法在头颈部鳞状细胞癌（鳞癌）中取得了很好的疗效，且临床应用安全。自2006年3月至2006年12月，我科应用重组人p53腺病毒（recombinant adenovirus—p53，rAd—p53，商品名为今又生）注射液对14例局部晚期或复发性头颈部鳞癌联合放化疗进行治疗，获得了较好的近期疗效，报道如下。

HCCR-1、P53在宫颈癌及其癌前病变中的表达及其临床意义

[目的]探讨人宫颈癌致癌基因-1（human cervical cancer oncogene-1，HCCR-1）、P53在宫颈癌及其癌前病变组织中的表达及临床意义。比较人乳头状瘤病毒（human papillomavirus ，HPV）检测与免疫组化法检测HCCR-1蛋白诊断宫颈上皮内瘤样变（cervical intraepithelianeoplasia ，CIN ）和宫颈癌的敏感度和特异度。[方法]采用免疫组化SP法检测 HCCR-1和P53在具有 HPV-DNA检测结果的40例宫颈癌、30例CIN Ⅰ、30例CINⅡ～Ⅲ和10例正常宫颈组织标本中的表达。[结果]① HCCR-1蛋白在正常宫颈组织中无表达，随着宫颈上皮病变的升级而呈现增高的趋势，各组间差异有统计学意义（ P ＜0．05）。②CIN Ⅰ、CIN Ⅱ～Ⅲ和宫颈癌P53表达阳性率显著高于正常宫颈（ P ＜0．05）。③ HCCR-1、P53在宫颈组织中的表达 HCCR-1、P53在宫颈组织的表达相关系数较低（ r ＝0．220，P ＝0．021），可认为两者没有相关性。④ HCCR-1、HR-HPV在宫颈组织的表达明显呈正相关（ r ＝0．9，P ＝0．000）。⑤免疫组化法检测 HCCR-1诊断CIN和宫颈癌的敏感度和特异度分别为71％和100％。[结论]在宫颈病变进展的过程中受多基因调控。 HCCR-1与突变型p53蛋白的表达随病理级别进展均呈逐步增加的趋势，在宫颈病变的发生发展中可能起着重要的作用。免疫组化法检测宫颈组织中 HCCR-1蛋白表达有望成为宫颈病变的诊断辅助工具。

P53和Bcl-2蛋白在基底细胞癌中的表达及临床意义

目的探讨P53、B细胞淋巴瘤/白血病-2基因(bcl-2)蛋白在基底细胞癌(BCC)组织中的表达及临床意义。方法用免疫组化链霉素抗生素蛋白-过氧化物酶连结(SP)法检测P53、Bcl-2蛋白在40例BCC(BCC组)组织中的表达,以20例正常皮肤组织作为对照组。结果 P53、Bcl-2蛋白在BCC组表达阳性率分别为55%(22/40)、85%(34/40),在对照组表达阳性率分别为15%(3/20)、10%(2/20)。P53、Bcl-2蛋白在BCC组中的表达明显强于对照组,差异有统计学意义(χ2=6.35、7.45,P<0.01)。结论 P53、Bcl-2蛋白的异常表达与BCC相关,说明其可能在BCC的发生及发展过程中起重要作用。

双氢青蒿素对人卵巢癌细胞株HO-8910裸鼠移植瘤的作用及P53表达的影响

目的探讨双氢青蒿素(DHA)对人卵巢癌细胞株HO-8910裸鼠皮下移植瘤的作用及P53表达的影响。方法将人卵巢癌细胞株HO-8910注入裸鼠的腋下,建立人卵巢癌移植瘤的动物模型,随机分为空白组,低剂量DHA组、中剂量DHA组、高剂量DHA组、顺铂阳性对照组,观察干预后各组移植瘤抑瘤率;免疫组织化学法和蛋白印迹法检测肿瘤细胞内P53蛋白的表达;应用实时荧光定量聚合酶链反应(RT-PCR)法测定移植瘤中P53 mRNA的表达。结果①DHA对裸鼠移植瘤的生长有一定的抑制作用,并具有浓度依赖性。②病理学观察见细胞的体积较大,胞质疏松,核深染,可有不同程度的核固缩、核碎裂及核溶解,细胞中可见局灶性坏死。③免疫组织化学法结果证实随着DHA剂量的增加突变型P53蛋白表达减弱;蛋白印迹法检测到DHA组野生型P53蛋白表达上调。④RT-PCR法检测到DHA组野生型P53基因表达上调。结论 DHA对人卵巢癌裸鼠皮下移植瘤的生长有明显的抑制作用,且与剂量有一定的关系,其机制可能与上调野生型P53的表达导致细胞凋亡有关。

Genetic aberration in primary hepatocellular carcinoma:correlation between p53 gene mutation and loss-of-heterozygosity on chromosome 16q21-q23 and 9p21-p23

To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on chromosome 9, 16 and 17. Loss-of-heterozygosity (LOH) is observed with high frequency on chromosomal region 17p13 (36/55, 65%), 9p21-p23 (28/55, 51%), 16q21-q23 (27/55, 49%) in tumors. Meanwhile, microsatellite instability is rarely found in these microsatellite loci. Direct sequencing was performed to detect the tentative mutation of tumor suppressor genes in these regions: p53, MTS1/p16, and CDH1/E-cadherin. Within exon 5-9 of p53 gene, 14 out of 55 HCC specimens (24%) have somatic mutations, and nucleotide deletion of this gene is reported in HCC for the first time. Mutation in MTS1/pl6 is found only in one tumor case. We do not find mutations in CDH1/E-cadherin. Furthermore, a statistically significant correlation is present between p53 gene mutation and loss of chromosome region 16q21q23 and 9p21-p23, which indicates that synergism between p53 inactivation and deletion of 16q21-q23 and 9p21-p23 may play a role in the pathogenesis of HCC. Genetic aberration in hepatocellular

Abnormal Change of p53 Gene in Gastric and PrecancerousLesions and APC Gene Deletion in Gastric Carcinoma and Near Tissues

p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP- Results showed mutation rate of p53 in metaplasia, dysplasia and gastric carcinoma was 37. 5 % (3/8), 42. 11 % (8/19), 53. 33 (16/30) respectively- There was significant dif-ference among groups of metaplasia, dysplasia, cancer and normal controls. Noexon8 mutation was found in metaplasia and dysplasia, but 4 cases were found to have exon8 mutation in cancer group. It is suggested that exon8 mutation occurs at the late stage of gastric cancer, but exon 5, 6, 7 mutation occur in the course ofprecancerous lesion to cancer. Loss of heterozygosity (LOH) of exon4, intron6,APC was 47,37 % (9/19), 8. 73% (2/23), 16. 67 % (3/18) respectively. LOH of exon4 had something to do with poor differentiation, lymph node metastasis,depth of invasion- LOH of exon4 may be one of prognostic marker of gastric cancer. We are led to conclude that p53 gene mutation is an early event and perhaps work together with ras oncogene in gastric carcinogenesis

ADENOVIRUS-MEDIATED P53 GENE TRANSFER INCREASES THE THERMOSENSITIVITY OF HUMAN GASTRIC CARCINOMA CELL LINES(IN VITRO AND IN VIVO)

Objective: To evaluate the effect of adenovirus-mediated p53 gene (Adp53) on apoptosis andradiosensitivity of human gastric carcinoma cell lines.Methods: Recombinant adenovirus expressing wild-type p53 gene was transferred into four human gastric carcinoma cell lines with different p53 genetic status. p53 proteinexpression was detected by immunohistochemistry assayand western blot assay. Cell survival was assessed using a clonogenic assay. TUNEL assay was used in determination of apoptosis. Four human gastric carcinoma cells infectedwith Adp53 were irradiated with 4Gy and cell cycle distribution and Sub-G1 peak were assayed by flowcytometry. Results: G2/M arrest, apoptosis and inhibition of tumor cell proliferation were induced by infection atAdp53 at 100 MOI which caused high transfer rate ofwild-type p53 and strong expression of p53 protein in four human gastric carcinoma cells. The radio-enhancement ratio of Adp53 at 4Gy were 3.0 for W cell, 3.6 for M cell, 2.2 for neo cell and 2.5 for 823 cell in vitro. Conclusion: Thisstudy demonstrated that Adp53 transfer increased cellularapoptosis and radiosensitivity of human gastric carcinoma cell lines in vitro independently on cellular intrinsic p53status thus supporting the combination of p53 gene therapy with radiotherapy in clinical trials.

Comparative Study of the Effect of Shugan Shuru Granule (疏肝舒乳颗粒) on Pathology and p53 Gene Expression in Patients with Hyperplastic Disease of Breast

Objective: To study the effect of Shugan Shuru Granule (疏肝舒乳颗粒,SSG) on the p53 gene expression in patients with hyperplastic disease of breast (HDB) to indirectly explore the mechanism of SSG’s effect on HDB on the molecular pathological level. Methods: Sixty-six patients with HDB were allocated in the treated group and the control group,with the former treated with SSG and the latter not. All patients underwent breast operation and their diseased mammary tissues were cut out, sectioned, and observed under microscopy with HE staining and immunohistochemical staining, with ABC method adopted to estimate the degree of hyperplasia and p53 gene expression. The severity of HDB was classified into normal, mild, moderate and severe grades (marked as 0 to Ⅲ), according to the degree of hyperplasia in the mammary gland. Results: Hyperplasia in the control group mostly belonged to grade Ⅰ-Ⅲ before treatment, showing overgrowth of gland and proliferation of glandular epithelial cells, which were high columnar shaped, more stratified, with papillary or substantive dysplasia. While in the treated group, most belonged to grade 0-Ⅰ after SSG treatment, with proliferated gland and dysplasia recovered to normal or disappeared. The positive rate of p53 gene expression in the treated group was 9.09%, and in the control group 39.39%, comparison between the two groups showing significant difference (P<0.01), the intensity in the former was significantly weaker than that in the latter.Conclusion: SSG could not only inhibit the proliferation of mammary duct epithelia and lobuli, but also inhibit the over-expression of P53. Therefore, it could be regarded as an effective remedy for treatment of HDB and prevention of mammary cancer genesis.

Protective effects of proanthocyanidins on beta-amyloid peptide (25-35)-induced PC12 cell apoptosis by blocking S-phase and increasing p53 gene expression

BACKGROUND： Current studies related to the effects of proanthocyanidins on Alzheimer＇s disease have focused primarily on the signal transduction pathway of cellular apoptosis. However, the influence of p53 gene expression on cell cycle regulation, with regard to the protective mechanisms of proanthocyanidins, has not been reported. OBJECTIVE： To observe the effect of proanthocyanidins on cell cycle distribution, cellular apoptosis and p53 gene expression in β-amyloid peptide （25-35） （Aβ25-35）-induced PC12 cells cultured in serum-free media, and to investigate the molecular neuroprotective mechanisms of proanthocyanidins with regard to cell cycle regulation. DESIGN, TIME AND SETTING： A parallel, controlled, at the Institute of Biochemistry and Molecular Biology cellular, and molecular study was performed Guangdong Medical College from July 2006 to July 2008. MATERIALS： Proanthocyanidins were provided by Nanjing Xuezi Medical and Chemical Research Center, China; Aβ25-35 was provided by Sigma, USA; PC12 cells were provided by the Institute of Basic Medical Science, Academy of Military Medical Sciences; and rabbit anti-p53 polyclonal antibody was provided by Santa Cruz Biotechnology, USA. METHODS： PC12 cells were cultured in serum-free media for 24 hours. Cells from the model group were treated with 25 μmol/L Aβ25-35 for 24 hours. Cells in the drug protection group were pre-treated with 30 mg/L proanthocyanidins for 1 hour and then treated with 25 μmol/LAβ2^-35 for 24 hours. The control group was not treated. MAIN OUTCOME MEASURES： Flow cytometry was used to detect cell cycle distribution and rate of apoptosis; reverse-transcriptase polymerase chain reaction was used to detect p53 mRNA expression; and Western blot was used to detect p53 protein expression. RESULTS： After treating with 25 μmol/LAβ25-35 for 24 hours, the rate of apoptosis and the percentage of cells in S phase were significantly increased （P 〈 0.01 ）, and p53 mRNA and protein expressions were decreased. Pretreatment with proanthocyanidins for 1 hour blocked the increase in apoptosis and the percentage of cells in S phase in Aβ25-35-induced PC12 cells （P 〈 0.01 ） and increased p53 mRNA and protein expressions. CONCLUSION： Proanthocyanidins blocked apoptosis and S-phase arrest in Aβ25-35-induced PC12 cells cultured in serum-free media. The protective mechanism could be related to increased p53 mRNA and protein expressions.

SUMO-1 Enhancing the p53-induced HepG2 Cell Apoptosis

In order to investigate the effect of small ubiquitin-like modifier-1 (SUMO-1) on the p53-induced HepG2 cell apoptosis, HepG2 cells were transfected by recombinant plasmids as pwtp53, pMDM2 and pSUMO-1 respectively. Western blot was employed to detect the protein expression of the transfected recombinant plasmids and the rate of apoptosis was measured by flow cytometry. The results showed that in cells transfected with pwtp53 and pwtp53+pSUMO-1, the apoptosis rate was (16.79±1.62) % and (18.15±1.36) % respectively, while transfected with pwtp53+pMDM2, the rate was decreased to (5.17±1.23) %. The apoptosis rate was (14.06±1.84) % in the cells transfected with pwtp53+pMDM2+pSUMO-1, significantly higher than that in the cells Transfected with pwtp53+pMDM2 (P<0.01). The apoptosis rates in the cells were all less than 2 % and had no significant difference among the groups. It was suggested that in the HepG2 cells, SUMO-1 can increase the apoptosis induced by wild-type p53 through binding to p53 protein, post-translational modification and inhibiting the p53 degradation by MDM2.

RELATIONSHIP BETWEEN THE MUTATION OF P53 GENE AND INFILTRATION，METASTASIS AND PROGNOSIS OF GASTRIC CARCINOMA

gastric carcinomas were examined immunohistochemically with McAb to p53 protein in order to investigate the relationship between the expression of p53 protein and histological differentiation of gastric carcinoma, and to approach the mechanism of infiltration and metastasis of gastric carcinoma. The results showed that nuclear expression of p53 protein was significantly related to tumor size, depth of invasion, lymph node and liver metastases; but not related to histological differentiation. It is suggested that the accumulation of p53 protein was increased with the progression of gastric carcinoma, and therefore the cancer clone with p53 gene mutation may play an important role in the development of tumor invasion and metastasis.

Specific intronic p53 mutation in esophageal squamous cell carcinoma in Southern Thailand

AIM:To investigate p53 mutations in esophageal cancer in a high-risk population,and correlate them with smoking,alcohol consumption and betel chewing.METHODS:One hundred and sixty-five tumor samples of esophageal squamous cell carcinoma(ESCC) obtained from a university hospital in Songkhla province,Southern Thailand were investigated for p53 mutations in exons 5-8,using polymerase chain reaction-single strand conformation polymorphism analysis,followed by direct sequencing.A polymerase chain reactionrestriction fragment length polymorphism(RFLP) assay was additionally used to confirm possible germline mutation in intron 6.A history of risk habits was obtained by interviews.The association between risk habits and mutation frequency was evaluated using the χ 2 test.RESULTS:The studied specimens were from 139 male and 26 female patients with ESCC,treated at Songklanagarind Hospital.Most of the patients were smokers(86.7%) and alcohol consumers(72.73%),and 38.3% were betel chewers.Forty-three mutations of the p53 gene were detected in 25.5%(42/165) of tumor samples.Mutations were most commonly found in exon 5(25.6%) and exon 8(25.6%).Mutations in the hot-spot codon 248 were found in four cases(9.3% of all mutations).G:C→C:G(30.23%),G:C→A:T(27.90%) and G:C →T:A(16.28%) were the prevalent spectra of mutations.Unexpectedly,among 10 intronic mutations,eight cases harbored a similar mutation:G→C substitution in intron 6(nucleotide 12759,GenBank NC_000017).These were additionally confirmed by the RFLP technique.Similar mutations were also detected in their matched blood samples using RFLP and direct sequencing,which suggested germline mutations.There was no significant correlation between risk habits and p53 mutation frequency.CONCLUSION:A proportion of Thai ESCC patients harbored specific intronic p53 mutations,which might be germline mutations.Further studies are needed to explore this novel finding.

PDRG1 at the interface between intermediary metabolism and oncogenesis

PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damageregulated gene 1(PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase Ⅱ complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.

RAS AND p53 EXPRESSION IN HUMAN THYROID CARCINOMA

Objective: To investigate the possible interaction between the ras and p53 genes over-expression in thyroid carcinoma, and whether there is a correlation between the ras and p53 over-expression and clinicopathological criteria. Methods: Eighty patients with thyroid lesions were examined for expression of ras and p53 genes by the labeled streptavidin biotin peroxidase (LSAB) method. Of these patients, 54 were diagnosed (average age: 39.9±15.9 years) with malignant lesions. Of those included in the study, 31 has papillary carcinoma, 13 had follicular carcinoma, 7 had medullary carcinoma, 3 had undifferentiated carcinoma and 19 were stratified to stage I, 28 to stage II, 2 to stage III and 5 to stage IV according to TNM staging system. Twenty-six benign nodular thyroid disorders were studied as control. Results: Positive immunostain results for ras and p53 genes were statistically significant between thyroid carcinomas and benign disorders (90.7% vs 23%, 55.5% vs 30.7%,P<0.05). Both p53 and ras overexpressions coexisted in 30 thyroid carcinomas, and of these, 3 died and 5 had recurrences within 4 years. Conclusions: Activation of ras gene and inactivation of p53 gene were cooperatively associated in thyroid tumorigenesis. The concurrent overexpressions of ras and p53 could result in a poor prognosis.

GROWTH INHIBITION OF HUMAN LARYNGEAL CANCER CELL WITH THE ADENOVIRUS-MEDIATED p53 GENE

Objective: In most laryngeal cancers, the function of p53 gene is down regulated. To explore the potential use of p53 in gene therapy of laryngeal cancer, by introducing wild-type p53 into laryngeal cancer cell line via a recombinant adenoviral vector, Ad5CMV-p53 and analyzing its effects on cell and tumor growth. Methods: A human laryngeal cancer, cell line Hep-2 was used. Recombinant cytomegalovirus-promoted adenoviruses containing human wild-type p53 cDNA was transiently introduced into Hep-2 line. The growth suppression of the Hep-2 cells and established s.c. squamous, carcinoma model was examined. The p53 protein expression was detected using immunohistochemical analysis. Results: The transduction efficiencies of Hep-2 cell line were 100% at a multiplicity of 100 or greater. The p53 protein expression peaked on day 2 after infection and lasted far 5 days. In vitro growth assays revealed cell death following Ad5CMV-p53 infected. In vivo studies, Ad5CMV-p53 inhibited the tumorigenicity of Hep-2 cell, and in nude mice with established s.c. squamous, carcinoma, nodules showed that tumor volumes were significantly reduced in mice that received peritumoral infiltration of Ad5CMV-p53. Conclusion: Adenovirus-mediated antitumor therapy carrying the p53 gene is an efficient method to inhibit laryngeal cancer growth. Transfection of laryngeal cancer cells with the wild-type p53 gene via Ad5CMV-p53 is a potential novel approach to the therapy of laryngeal cancer.

DETECTION OF p53 GENE MUTATION OF BRONCHOSCOPIC SAMPLIES IN THE PATIENTS SUSPECTED TO LUNG CANCER

Objective: To determine the feasibility of detecting p53 gene mutations for early diagnosis of lung cancer using the samples from bronchoscopic examination. Methods: Point mutations of the exon 5-8 of p53 gene were detected in 85 bronchoscopic samples of 35 patients suspected to be lung cancer using silver staining PCR-SSCP. Results: p53 gene mutations were founded in 10 of 35 patients(28.6%). The incidence of p53 gene mutations (14.9%) was obviously higher than the cytological positive incidence(2.9%) in samples of sputum, bronchoalveolar lavage and brush, especially for the sputum(27.7%). In the bronchoscopic biopsy specimens, the incidence of p53 gene mutations (12.5%) was lower than that of pathologic positive result (50.0%). However, in view of all the bronchoscopic samples, there was no statistically difference between cytopathologic positive results (11.8%) and the incidence of p53 gene mutations (14.1%). Although the p53 mutations were most common in the samples from the patients bronchoscopically manifested as neoplasm compared with other manifestations, there was no statistical difference. It is valuable to notice that 3 patients with p53 gene mutation merely presented as bronchial inflammation in bronchoscope. Conclusion: Results indicated that the value of detecting p53 gene mutation for the diagnosis of lung cancer using the bronchoscopic samples was more superior to cytological examination and detection of p53 gene mutations in post-bronchoscopic sputum was easy and effective, may be used as a valuable method for early diagnosis of lung cancer.

ADENOVIRUS-MEDIATED WILD-TYPE P53 EXPRESSION SUPPRESSES GROWTH OF LUNG ADENOCARCINOMA CELLS

Objective: To study the growth suppression of lung adenocarcinoma cell by the introduction of wild type P53 gene and explore a gene therapy approach for lung adenocarcinoma. Methods: A replication deficient adeno virus vector encoding a wild type P53 was constructed and transfected into the cultured human lung adeno carcinoma cell line GLC 82. The efficiency of gene transfection and expression was detected by immuno chemical staining and polymerase chain reaction. The cell growth rate and cell cycle were analysed by cell counting and flow cytometry. Results: Wild type P53 gene could be quickly and effectively transfected into the cells by adenovirus vector. Wild type P53 expression could inhibit GLC 82 cell proliferation and induce apoptosis. Conclusion: The results indicated that recombinant adenovirus expressing wild type P53 might be useful vector for gene therapy of human lung adenocarcinoma.