人鼻咽与鼻咽癌cDNA阵谱中DNA修复相关基因表达差异的初步研究

目的 用cDNA阵卤咽癌组织及正常组织的基因表达谱,研究鼻咽癌组织内修复相关基因的表达差异。方法 Atlas human cancer cDNA expression array 7742-1杂交后,用Atlas Image 1.01a分析滤膜杂交结果,RT－PCR反应验证滤膜杂交结果。结果 在588个肿瘤相关基因中,共有134个基因表达上调,88个基因表达下调。在有DNA损伤应答、修复、重组相关基因的C区中,表达上调的基因有21个,与修复相关的有6个;表达下调的有44个,与修复相关的则有12个。结论 DNA修复相关基因的改变可能在鼻咽癌病理生理过程中起一定作用。     

人鼻咽与鼻咽癌组织p53调节基因差异表达的研究

目的 用cDNA Array比较鼻咽癌组织及正常组织基因表达谱,研究鼻咽癌组织内p53调节基因表达差异。方法 Atlas人类肿瘤cDNA表达阵列7742－1滤膜杂交后,用AtlasImage 1.01a分析膜杂交结果,RT－PCR反应验膜杂交结果,免疫组化证实基因在蛋白质水平的表达改变。结果 在588个肿瘤相关基因中,共有134个基因表达上调,88个基因表达下调。膜上有p53调节基因32种,其中13种显示差异表达,有11个表达上调,2个表达下调。结论 在鼻咽癌组织内,p53的功能失控,MDM2、p21和Bax可能对鼻咽癌细胞的生长起重要的调控作用。     

用高密度cDNA微阵列技术检测鼻咽癌差异表达基因

背景与目的：鼻咽癌的发生与发展涉及多个步骤,多个因素的参与,对此目前尚缺乏了解,本研究试图通过大规模检测鼻咽癌的基因差异表达来揭示鼻咽癌的差异表达基因谱,以发现与鼻咽癌发生,发展相关的新的候选基因。方法：用由18000个基因构建的高密度cDNA微阵列对21例鼻咽癌分3个样本池分别检测并与鼻咽非癌组织作对比分析。随机选2个基因用半定量RT－PCR验证检测结果。结果：3个样本池鼻咽癌差异表达基因分别为186个,95个和36个,总数达317个,表达上调的277个,表达下调的40个,差异表达基因中2个样本池以上有共同差异表达的基因有23个,表达上调的16个,表达下调的7个,其中3个样本池表达均有差异者6个,5个上调,1个下调,5个上调的基因中2个是已知基因,3个是未知基因,1个下调的是未知基因。结论：本研究揭示了鼻咽癌的基因表达谱,为了解鼻咽癌发生,发展的分子机理提供了大量信息,为寻找鼻咽癌相关基因提供了重要线索。     

用芯片技术分析鼻咽癌周围的基质细胞基因表达特点

背景与目的：鼻咽的基质细胞是如何参与鼻咽癌的癌变过程一直是研究的热点,本研究利用芯片技术分析鼻咽癌周围的基质细胞基因表达特点。探讨基质细胞在鼻咽癌发生和发展中的可能机制。方法：采用atlas human select tumor array滤膜,通过比较鼻咽癌组织和鼻咽癌细胞系的基因表达谱,获得鼻咽癌周围的基质细胞基因表达特点。结果：鼻咽癌周围的基质细胞至少可以特异地表达40个基因显示。结论：鼻咽癌周围的基质细胞具有基因的特异表达。     

TP53 status determines clinical significance of ERBB2 expression in ovarian cancer

ERBB2 expression has been found in 19 to 44% of ovarian carcinomas; however, its predictive value has not been demonstrated, and trastuzumab has not found clinical application in ovarian cancer patients. We evaluated clinical significance of ERBB2 expression in relation to TP53 accumulation in ovarian carcinoma patients treated with platinum-based regimens. Immunohistochemical analysis with CB11 and a novel NCL-CBE356 antibody (against the internal and external domains of ERBB2, respectively) was performed on 233 tumours (FIGO stage IIB-IV); the US Food and Drug Administration-approved grading system with 0 to 3+ scale was used for evaluation, and the results were analysed by the Cox and logistic regression models. In all, 42% of the tumours expressed (category 1+, 2+ or 3+) either CB11 or CBE356 or both (CB11/CBE356 parameter). Associations between ERBB2 expression and clinical factors were observed only if tumours with staining category 1+ were grouped together with tumours showing staining categories 2+ and 3+. CB11/CBE356 parameter had a better predictive value than CB11 alone. CB11/CBE356 expression was negatively associated with platinum sensitivity (PS) in the TP53(-) group (P=0.022) and with disease-free survival (DFS) in the TP53(+) group (P=0.009). Our results may suggest that trastuzumab should be given postoperatively to patients with TP53(-)/ERBB2(+) ovarian carcinomas to enhance PS, and after completion of chemotherapy to patients with complete remission and TP53(+)/ERBB2(+) carcinomas to extend DFS time (in total to 30.4% of all patients analysed). Thus, novel criteria for ovarian cancer patient inclusion for clinical trials with trastuzumab should be considered and tested.     

TP53 mutations in early-stage ovarian carcinoma, relation to long-term survival

We conducted the present study to evaluate the frequency and prognostic importance on long-term survival of TP53 mutations and TP53 protein accumulation in a cohort of 178 patients with early-stage ovarian carcinomas. TP53 mutations scored as aberrant temporal temperature gradient gel electrophoresis pattern from all exons were observed in 39.9% of the tumours. Full screening of exons 5-8, followed by sequencing, was successful in 135 cases, and 48 mutations altering the protein were detected in 39 cases (28.9%). TP53 mutations were slightly less common in the Federation of Gynecologists and Obstetricians stage IA than in IB/IC (P=0.05). No significant correlations with histological type, grade of differentiation, DNA ploidy status or age at diagnosis were found. TP53 protein accumulation analysed by immunohistochemistry was found in 32.6% of all tumours, and was a poor predictor of TP53 mutations with 56.4% sensitivity, 77.1% specificity, 50% positive predictive value and 81.3% negative predictive value. Neither TP53 mutations nor TP53 protein accumulation influenced the prognosis significantly in this group of patients.     

Alterations of theTP53 gene and TP53 protein expression in epithelial ovarian cancer before and after chemotherapy

Background A role for theTP53 (alias p53) tumor-suppressor gene in chemoresistance has recently been discussed, but little is known about the clinical relevance of theTP53 gene to chemoresistance. To elucidate the relevance ofTP53 status to chemoresistance, we investigated theTP53 gene and TP53 protein expression in tumors from the same patients, before and after chemotherapy. Methods Twenty-one patients with ovarian cancer, who had residual disease after primary surgery, were studied. These patients received chemotherapy consisting of cisplatin, doxorubicin, and cyclophosphamide, and then underwent a second surgery. Polymerase chain reaction-single strand conformation polymorphism analysis and cycle sequencing were performed to determineTP53 mutation. TP53 protein was detected by Western blot analysis. Results Of the 21 patients studied, 9 responded to chemotherapy. Mutation of theTP53 gene was seen in 7 patients (2 responders and 5 nonresponders) before chemotherapy. After chemotherapy, another mutation of the gene was observed in 5 patients, all of whom were nonresponders. TP53 protein was detected in 10 patients (3 responders and 7 nonresponders) before chemotherapy. After chemotherapy, the expression of TP53 protein increased in these 3 nonresponders, and became positive in 2 other nonresponders. Conclusions This study showed for the first time in clinical investigation that alterations toTP53 could develop in association with chemotherapy, and thatTP53 status may relate to the mechanisms of chemoresistance in patients with epithelial ovarian cancer.     

Effects of p53 overexpression on neoplastic cell mitosis and apoptosis in nasopharyngeal carcinoma

p53 gene alteration is an important molecular event in tumourigenesis of many malignancies.[1] However, the mutation rate of p53 gene in nasopharyngeal carcinoma (NPC) is lower.[2] The PCR-SSCP performed by FU Mao-fu et al. in the authors' lab in 1994 demonstrated that there were only 4 specimens showing aberrant shift in 18 NPCs (22.2%)--one in exon 5, three in exon 8.[3] On another aspect, the p53 overexpression rate almost reached about 80%.[4,5] It is well known that because the half…     

BCL-2, TP53 and BAX protein expression in superficial urothelial bladder carcinoma

Whether TP53, BCL-2 and BAX expressions add independent prognostic information in patients with Ta/T1bladder urothelial carcinoma remains unclear. TP53 overexpression correlated with high tumor grade (p = 0.004), WHO grading categories (0.045), BAX expression (p = 0.043) and pathologic stage (p = 0.05). BCL-2 immunostaining was inverse associated with tumor grade (p = 0.008). Lack of BAX expression was related to reduced patient’s survival (p = 0.028). Mortality was higher in patients with BCL-2+/TP53+ (p = 0.023) or TP53+/BAX− (p = 0.027) phenotype. BAX and pathologic stage were independent predictors of progression-free and overall survival, respectively. Therefore, BAX expression might be relevant in patient’s prognosis.     

鼻咽癌中p53蛋白积聚对瘤细胞有丝分裂和凋亡的影响

目的：观察疗前鼻咽癌组织中Ｐ５３蛋白的积聚及其对瘤细胞有丝分裂和凋亡的影响。方法随机收集１９９７年疗前鼻咽癌活检标本４３例,采用免疫组化ＬＳＡＢ法ＤＯ－７一抗检测Ｐ５３蛋白的表达。在Ｈ＆Ｅ染色切片上位细胞死亡试剂盒检测瘤细胞凋亡,平均每个高倍视野下的凋亡瘤细胞数为凋亡指数（ＴＵＮＥＬ ｉｎｄｅｘ,Ｔ１）。比较高于位细胞死亡试剂盒检测瘤细胞凋亡,平均每个高倍视野下的细胞瘤细胞数为凋亡指数（ＴＵＮＥＬ     

TP53基因突变与口腔鳞状细胞癌预后的关系

口腔鳞状细胞癌（OSCC）是口腔癌中最常见的类型,在头颈部癌患者中发病率较高并且预后不佳。 OSCC患者的当前治疗方法主要为外科手术、化学疗法、生物疗法和放射疗法等。尽管这些治疗方法已经取得了进步,但过去几年的总生存率仍然很低。 TP53基因作为一个重要的抑癌基因一直是肿瘤分子生物学研究的热点,近年来多项研究结果表明TP53突变与OSCC患者的生存率下降以及肿瘤对放疗和化疗的抵抗力等不良预后有关,这使得TP53突变状态成为预测这些患者预后和临床反应的潜在分子标记。为了更深入地了解 TP53基因在OSCC诊疗中的临床价值,本文拟就 TP53基因突变与OSCC预后的关系以及治疗研究进展进行综述。     

Tracking sub-clonal TP53 mutated tumor cells in human metastatic renal cell carcinoma

Renal Cell Carcinomas (RCCs) are heterogeneous tumors with late acquisition of TP53 abnormalities during their evolution. They harbor TP53 abnormalities in their metastases. We aimed to study TP53 gene alterations in tissue samples from primary and metastatic RCCs in 36 patients followed up over a median of 4.2 years, and in xenografted issued from primary RCCs.In 36 primary RCCs systematically xenografted in mice, and in biopsies of metastases performed whenever possible during patient follow-up, we studied p53-expressing tumor cells and TP53 gene abnormalities.We identified TP53 gene alterations in primary tumors, metastases and xenografts.Quantification of tumors cells with TP53 gene alterations showed a significant increase in the metastases compared to the primary RCCs, and, strikingly, the xenografts were similar to the metastases and not to the primary RCCs from which they were derived.Using laser-microdissection of p53-expressing tumor cells, we identified TP53-mutated tumor cells in the xenografts derived from the primary RCC, and in a lung metastasis later developed in one patient. The mutation enabled us to track back their origin to a minority sub-clone in the primary heterogeneous RCC.Combining in situ and molecular analyses, we demonstrated a clonal expansion in a living patient with metastatic RCC.     

不同p53功能状态鼻咽癌细胞株的放射生物学特性

目的探讨鼻咽癌细胞不同p53功能状态及其放射生物学特性之间的关系。方法采用脂质体介导的转染方法将携带野生型p53基因的真核表达质粒pC53-SN3，空载体质粒pCMV-NeoBarn分别转染到鼻咽癌细胞CNE1、DNE2中。p53功能检测技术明确细胞转染p53基因前后的p53功能状态。成克隆实验测定细胞存活分数。采用单击多靶模型和线性二次函数模型拟合细胞存活曲线，求出放射生物学参数Do、Dq、N和α、β、α/β、SF2值。结果转染野生型p53基因后鼻咽癌细胞获得正常p53功能。CNE1-pNeo和CNE1-wtp53细胞的％值分别为1．17、1．08Gv；Dq值分别为2．25、1．21Gy；Q值分别为0．13、0．29Gy^-1；SF2值分别为0．765、0．326。CNF2-pNeo和CNE2-wtp53细胞的Do值分别为0、92、0．84Gy；Dq值分别为1．45、1．04Gy；α值分别为0、13、0．76Gy^-1；SF2值分别为0．675、0．156。CNE1、CNE2细胞转染野生型p53基因后，Do、Dq、SF2值均减小，α值增大。结论野生型p53基因转染可以提高p53功能缺陷的鼻咽癌细胞的放射敏感性。     

TP53基因在特定血液病和淋巴瘤中的研究进展

TP53基因是重要的抑癌基因之一,其编码的蛋白——肿瘤抑制蛋白p53能够使许多基因保持其稳定性,并调节细胞的生长、分化、衰老,避免疾病产生,被称为“基因守护者”。当TP53基因缺失、突变和调节紊乱时,将直接影响p53蛋白的功能和活性,从而导致很多肿瘤的发生;除此之外TP53的基因状态也成为判断淋巴瘤和血液病预后的重要指标。本文通过综述TP53基因缺失和突变在不同血液病和淋巴瘤中的意义,使人们对TP53基因与血液肿瘤和淋巴瘤的关系有更清晰的认识。     

基于质谱流式细胞技术揭示TP53突变型乙型肝炎病毒相关性肝细胞癌的免疫微环境特征

目的 探讨TP53突变型乙型肝炎病毒（hepatitis B virus,HBV）相关性肝细胞癌（hepatocellular carcinoma,HCC）的肿瘤免疫微环境特征。方法 收集2018—2019年广西医科大学附属肿瘤医院肝胆外科手术切除的38例HCC患者活体组织标本及其配对癌旁组织标本,提取组织DNA,并进行基因突变分析。采用质谱流式细胞术（CyTOF）比较TP53突变组和TP53未突变组中癌组织与癌旁组织以及两组癌组织之间的免疫微环境特点。结果 采用CyTOF鉴定TP53突变组和TP53未突变组所有免疫细胞,结果鉴定为22个细胞亚群,包括CD4⁺T细胞亚群、CD8⁺T细胞亚群、B细胞亚群、树突细胞亚群、自然杀伤（natural killer cell,NK）细胞亚群、NKT细胞亚群、粒细胞亚群和2个未知细胞亚群。其中,TP53突变组癌组织中CD8⁺T细胞和CD4⁺T细胞的表达比例均较未突变组癌组织高（2.26% vs 0.47%,P=0.028;7.53% vs 3.55%,P=0.046）。结论 TP53突变型HBV相关性HCC的肿瘤免疫微环境具有免疫异质性。     

Ser-249 TP53 and CTNNB1 mutations in circulating free DNA of Egyptian patients with hepatocellular carcinoma versus chronic liver diseases

Circulating free DNA (CFDNA) has been shown to be a good source of liver tissue-derived DNA in African and Asian patients with chronic liver disease or HCC. In Egypt, HCC is a frequent carcinoma and mostly occur in the context of chronic infection by HCV, a widespread infection in the Egyptian population. Here we have examined the presence of mutations in TP53 at codon 249 (Ser-249, considered as a hallmark of mutagenesis by aflatoxin) and in CTNNB1 (gene encoding β-catenin) in CFDNA of patients with HCC or chronic liver disease, from Alexandria, Egypt. The DNA concentrations were significantly higher in HCC patients compared to HBV and HCV carriers without cancer, and to sero-negative individuals. Ser-249 TP53 mutations were determined using PCR-restriction digestion (RFLP) in CFDNA of 255 subjects, and confirmed by sequencing. Ser-249 was found in CFDNA of 12 subjects (4.8%), with the highest prevalence in subjects with chronic liver disease and infection by HBV (6/36; 16.7%) Mutations in CTNNB1 were examined using PCR combined to DHPLC and followed by sequencing. No mutations were found in CTNNB1 neither in CFDNA or in tumour tissue. In parallel, studies on DNA extracted from 20 HCC biopsies showed the presence of ser-249 mutation in two cases (10%). These results indicate that mutagenesis by aflatoxin may play a role in hepatocarcinogenesis in Egypt, and CFDNA may serve as a convenient source of material in monitoring the effects of aflatoxin exposure and viral infections in chronic liver disease and cancer.     

Worse survival for TP53 (p53)-mutated breast cancer patients receiving adjuvant CMF.

BACKGROUND: TP53 has been described as a prognostic factor in many malignancies, including breast cancer. Whether it also might be a predictive factor with reference to chemo- and endocrine therapy is more controversial. PATIENTS AND METHODS: We investigated relapse-free (RFS), breast cancer-corrected (BCCS) and overall survival (OS) related to TP53 status in node-positive breast cancer patients that had received polychemotherapy [cyclophosphamide, methotrexate, 5-fluorouracil (CMF)] and/or endocrine therapy (tamoxifen). Sequence analyses of the whole TP53 coding region was performed in 376 patients operated on for primary breast cancer with axillary lymph node metastases between 1984 and 1989 (median follow-up time 84 months). RESULTS: TP53 mutations were found in 105 patients (28%). We found 90 (82%) of the 110 mutations in the more frequently analysed exons 5-8, while the other 20 (18%) were located in exons 3-4 and 9-10, respectively. Univariate analyses showed TP53 to be a significant prognostic factor with regard to RFS, BCCS and OS in patients who received adjuvant CMF. CONCLUSIONS: TP53 mutations might induce resistance to certain modalities of breast cancer therapy. Sequence-determined TP53 mutation was of negative prognostic value in the total patient population and in the CMF treated patients.     

Activation of AKT and nuclear accumulation of wild type TP53 and MDM2 in anal squamous cell carcinoma

Human papilloma virus (HPV) infection is considered as an important aetiological factor for anal squamous cell carcinoma (ASCC) but is not sufficient for tumour progression. This carcinoma is poorly understood at the molecular level. Using the largest cohort of cases to date we investigated the molecular mechanisms underlying ASCC development, in particular the roles of TP53, MDM2 and AKT. Viral infection in our cohort occurred at high frequency (73%, 94/128) with HPV16 accounting for the majority (86%, 81/94) of infected cases. Only 4% (5/119) of ASCCs showed TP53 (exons 5-8) mutations, but a high frequency (91%, 100/110) of nuclear protein expression of TP53 was observed. There was a significant association (p < 0.001) between nuclear accumulation of TP53 and MDM2 protein although no MDM2 mutations were found, and copy number was normal. Cellular accumulation of phosphorylated-AKT was observed in 66% (82/125) of ASCCs and an association demonstrated between nuclear accumulation of MDM2 and activated AKT (p < 0.001). We observed a high frequency of copy number gain at PIK3CA (47%), and some coding sequence mutations (4%). Amplification of PIK3CA was associated with presence of phosphorylated-AKT (p= 0.008). There was no association between virus infection and TP53 nuclear accumulation (p = 0.5). However, a significant association was found between infection and MDM2 nuclear staining, and between infection and activated AKT (p = 0.04, p = 0.01, respectively). We propose that activation of AKT, possibly through the PI3K-AKT pathway, is an important component of ASCC tumorigenesis that contributes to MDM2 and TP53 accumulation in the nucleus.