The genetic events of HPV-immortalized esophageal epithelium cells

We studied cytogenesis, telomere and telomerase, and c-myc, ras, bcl-2, and p53 genes of cells in the progressive process of immortal epithelial cells from embryonic esophagus induced by human papillomavirus (HPV). The SHEE cell line, established by us, consist of immortalized epithelial cells from the embryonic esophagus induced by genes E6E7 of HPV type 18. It was in initial malignant transformation when cultivated over 60 passages without co-carcinogens. Cells of the 10th, 31st, and 60th passages were represented in the progressive process within the immortal period. In these three stages of the cell line, the modal number of chromosome and karyotypes were analyzed. The telomere length was assayed by Southern blot methods, and the telomerase activity was analyzed by hTR and hTERT assay. C-myc, p53, bcl-2, ras genes were assayed by the multi-PCR method. The morphology of the 10th passage cells exhibited good differentiation, the 60th passage cells were relatively poorly differentiated, and the 31st passage cells differentiated in two distinct ways. The growth characteristics of the 31st and 60th passage cells were weakened at contact-inhibition and anchorage-dependent growth. Karyotypes of three cell passages belonged to hyperdiploid and hypotriploid with abnormal chromosomes +1, +3, +7, +9, +17, +18; del(1)(p32); der(4), t(4;?)(q31;?); der(5),t(5;?)(q31;?); der(13),t(13;13)(p11;q11) and others. Bimodal distribution of chromosomes with more aberrant chromosomes appeared in the 31st and 60th passage cells. Telomere length sharply shortened from normal fetal esophagus to the 10th and 31st passage step by step, but was stable from the 31st to the 60th passage and the telomerase activities measured were expressed at late two passages. p53 mutant was positive in three passages, c-myc was positive in the 31st and the 60th passage K-ras only in the last. The results reveal that changes of chromosomes, telomere length, telomerase activity and certain gene expressions are important events of HPV-immortalized esophageal epithelium cells. All of these changes occurred in dynamic progressive process. This cell line may be useful for the elucidation of the genetic mechanism of cellular immortalization.     

A comparative study of telomerase activity and malignant phenotype in multistage carcinogenesis of esophageal epithelial cells induced by human papillomavirus.

To examine certain characteristics of multistep carcinogenesis, we studied telomerase activity and malignant phenotypes in the immortal, premalignant and malignant stages of esophageal epithelial cells induced by HPV. An immortalized human fetal esophageal epithelial cell line (SHEE) was induced by E6E7 genes of human papillomavirus (HPV) type 18. Cells in the 10th passage, (SHEE10), 31st passage (SHEE31), 61st passage (SHEE61) and SHEE61A which were selected and expanded from anchorage-independent growth colonies of SHEE61, were examined as follows: cell morphology by electron-microscopy; the cell cycle by flow cytometry, telomerase activity by TRAP assay, tumorigenic detection including anchorage-independent growth by soft agar culture and tumor formation by inoculating cells into SCID and nude mice, and detection of HPV18 E6E7 oncoprotein by Western blot. The morphology of the SHEE10 cells exhibited good differentiation, the SHEE60 and SHEE61A cells were relatively poorly differentiated, and the SHEE31 cells were differentiated in two distinct ways. The telomerase was activated in SHEE31, SHEE61 and SHEE61A, but not in SHEE10 cells. SHEE61 and SHEE61A cells were weakened in contact-inhibition and increased in anchorage-independent growth. Inoculated into SCID and nude mice, the cells of the earlier two passages could not develop tumors; the SHEE61 developed one tumor in four SCID mice, but not in nude mice, and the SHEE61A cells developed tumors in both strains of immunodeficient mice. HPV18 E6E7 DNA detection by Western blotting was positive in all cell passages. In the process of carcinogenesis by HPV, the cells of SHEE31 are in an immortalized state with telomerase activity. The fact that SHEE61 cells remained immortalized and also demonstrated anchorage-independent growth, reveals premalignant character; the cells of SHEE61A exhibited malignant transformation with tumor formation in mice. The results revealed that the telomerase activity, anchorage-independent growth and tumor formation in nude mice are the indicators for immortalization, premalignancy and malignancy, respectively.     

Identification of pathways and genes in the process of E6/E7-induced carcinogenesis of esophageal epithelial cells

Human papillomavirus (HPV) infection was associated with some carcinomas, especially malignant tumors in upper digestive tract, upper respiratory tract, and genitourinary system. The mechanism of the viral transformation of normal cells is still not very clear. To investigate the tumorigenesis of epithelial cells, E6/E7-induced malignant transformation model cells were used for expression profiling analysis by performing RNA expression microarray detection. Bioinformatics analysis was applied to investigate the cellular process changes along with the E6/E7 expression in SHEE cells. The differentially expressed genes were further grouped and uploaded for Search Tool for the Retrieval of Interacting Genes analysis. The protein-protein interaction results were visualized. The hub genes and their first-neighbors genes were selected, followed by gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. The obtained results demonstrated that tumor-related biological processes began to emerge during the carcinogenesis process from 48th passage to 76th passage of SHEE cells after E6/E7 expression. Ten hub genes were identified and analyzed during the E6/E7-induced tumorigenesis. This study explores the gene expression network in the progressive transformation of immortalized esophageal epithelial cells induced by E6/E7 expression. Understanding the biological processes and hub genes that first appear during the transformation will provide some clues to the mechanism of E6/E7-induced carcinogenesis of esophageal epithelial cells.     

腺病毒伴随病毒表达载体表达人乳头瘤病毒18型E6E7基因构建及其转化作用的鉴定

目的：探讨人乳头瘤病毒（HPV）的E6E7基因在细胞恶性转化中所起的作用。方法：将人乳头瘤病毒（HPV）的E6E7基因克隆至腺病毒伴随病毒表达载体中，通过包装的重组病毒感染，将E6E7基因导入并整合到永生293细胞的基因组中。结果：本研究成功地构建了HPV18 E6E7 AAV病毒并感染了永生293细胞，PCR／Southern杂交分析表明E6E7基因在转化细胞293TL中确有表达，转化细胞293TC和293TL具有明显的转化表型，和亲本293细胞相比，生长速度快，接触抑制消失，集落形成率提高20倍，且集落明显增大，形成时间短。结论：成功地构建了HPV18 E6E7 AAV病毒，HPV18 E6E7基因引起永生化人上皮细胞293的恶性转化。此病毒可用于感染正常上皮细胞，研究其致癌机制。     

人乳头状瘤病毒18型E6E7基因诱导人胚食管上皮永生化

目的为研究病毒和肿瘤的关系,用人乳头状瘤病毒（ＨＰＶ）１８型Ｅ６Ｅ７基因感染胎儿食管上皮,建立一株新的人食管上皮永生化细胞株（ＳＨＥＥ）。方法ＨＰＶ１８Ｅ６Ｅ７腺病毒伴随病毒（ＨＰＶ１８Ｅ６Ｅ７ＡＡＶ））载体的构建;胚胎食管组织培养,ＨＰＶ１８Ｅ６Ｅ７ＡＡＶ感染,继续培养传代。用光镜、电镜检查其形态;聚合酶链反应（ＰＣＲ）、荧光原位杂交（ＦＩＳＨ）检查该病毒片段;用软琼脂培养和裸鼠接种检查致瘤性。结果经过长时间的传代培养,ＳＨＥＥ的表型仍保留原代上皮细胞培养的特征,表现为单层生长和锚锭依赖性生长,在软琼脂培养不形成克隆,接种裸鼠未成瘤。ＳＨＥＥ细胞系电镜检查可见张力原纤维,免疫组织化学检查细胞角质蛋白阳性,证实为鳞状上皮来源。ＦＩＳＨ和ＰＣＲ检测显示有ＨＰＶ１８Ｅ６Ｅ７基因。结论用ＨＰＶ１８Ｅ６Ｅ７基因建立食管上皮永生化细胞株ＳＨＥＥ,支持ＨＰＶ１８可能和食管癌病因有关的观点,可进一步用以研究食管癌的病因和发病机制。     

亚硝基吡啶对人乳头状瘤病毒诱导的食管上皮永生化细胞的促癌作用

目的 观察亚硝基吡啶在细胞恶性转化过程中的促癌作用.方法 用HPV18E6E7诱导食管上皮细胞永生化细胞系SHEE,第17代细胞培养在50 ml培养瓶.加入亚硝基吡啶（Nnitrosopiperidine,NPIP）0,2,4,8 mmol/L作用3周.用相差显微镜检查细胞形态,流式细胞仪检测细胞增殖和凋亡;染色体常规制样,检查染色体众数;细胞软琼脂集落形成及接种裸小鼠检查成瘤性;用Western blot检测HPV18表达.结果 当细胞暴露在8 mmol/L NPIP时细胞死亡增加,只剩少量活细胞.换正常培基代替NPIP,经4周后细胞进入增殖状态,细胞出现增生和异型增生.第8周末细胞软琼脂培养有大集落形成,接种裸小鼠成瘤.2,4 mmol/L组细胞倍增时间延长,细胞未能成瘤.8 mmol/L NPIP组染色体众数61～65,对照组56～61.实验组和对照组HPV阳性.结论 NPIP促进人乳头状瘤病毒诱导人胚食管永生化上皮恶性转化,HPV18E6E7和NPIP能协同作用加速食管上皮恶性转化.     

人宫颈癌中C—myc,H—ras和HPV基因的检测和分析

收集６０例宫颈癌活检组织，对同一病例同时进行ＨＰＶ、Ｃ－ｍｙｃ，Ｈ－ｒａｓ对比研究。采用ＨＰＶ高保守序列区一对共有引物检测多型ＨＰＶ基因型的存在，发现８５％（５１／６０％的组织中存在ＰＨＶ，经限制性片段长度多态性分析，ＨＰＶ１６占７８．４３％（４０／５１），ＨＰＶ１８占２１．６５％（１１／５１）。     

Immortal human pancreatic duct epithelial cell lines with near normal genotype and phenotype

Immortal epithelial cell lines were previously established after transduction of the HPV16-E6E7 genes into primary cultures of normal pancreatic duct epithelial cells. Single clones were isolated that demonstrated near normal genotype and phenotype. The proliferation of HPDE6-E6E7c7 and c11 cells is anchorage-dependent, and they were nontumorigenic in SCID mice. The cell lines demonstrated many phenotypes of normal pancreatic duct epithelium, including mRNA expression of carbonic anhydrase II, MUC-1, and cytokeratins 7, 8, 18, and 19. These cells have normal Ki-ras, p53, c-myc, and p16(INK4A) genotypes. Cytogenetic studies demonstrated losses of 3p, 10p12, and 13q14, the latter included the Rb1 gene. The wild-type p53 protein was detectable at very low levels consistent with the presence of E6 gene product, and the lack of functional p53 pathway was confirmed by the inability for gamma-irradiation to up-regulate p53 and p21waf1/cip1 protein. The p110/Rb protein level was also not detectable consistent with the expression of E7 protein and haploid loss of Rb1 gene. Despite this, the proliferation of both c7 and c11 cells were markedly inhibited by transforming growth factor-beta1. This was associated with up-regulation of p21cip1/waf1 but not p27kip1. Further studies showed that p130/Rb2 and cyclin D3 were expressed, suggesting that p130/Rb2 may have partially assumed the maintenance of G(1) cell cycle checkpoint regulation. These results indicate that except for the loss of p53 functional pathway, the two clones of HPDE6-E6E7 cells demonstrated a near normal genotype and phenotype of pancreatic duct epithelial cells. These cell lines will be useful for future studies on the molecular basis of pancreatic duct cell carcinogenesis and islet cell differentiation.     

Degradation of p53 only is not sufficient for the growth stimulatory effect of human papillomavirus 16 E6 oncoprotein in human embryonic fibroblasts

Certain types of human papillomavirus (HPV), such as types 16 and 18, are thought to be responsible for the development of cervical carcinomas. The E6 and E7 genes of these viruses have transforming activities in various cultured cells and their mRNAs and proteins are expressed in almost all cervical carcinoma cells. Inactivation of the tumor suppressor p53 protein by the E6 gene is believed to be critical for transformation by these oncogenic HPVs. To determine whether degradation of the p53 protein is, in fact, sufficient for cellular transformation by the E6 gene, the E6 gene of HPV16 was introduced into human embryonic fibroblasts (HEF) using recombinant murine retrovirus and examined whether reduction of the p53 protein could substitute for the E6 function. It was found that HEF cells transfected with the E6 gene showed an increased saturation density and degraded the p53 protein. However, when expression of the p53 protein in normal HEF cells was suppressed by the antisense oligonucleotide of the p53 gene, growth stimulation was not observed. These results show that the E6 gene stimulates growth of HEF cells, but that this activity involves some other E6 gene-mediated functions than degradation of the p53 protein. © 1994 Wiley-Liss, Inc.     

HPV16,18E6蛋白与p21ras,p53在食管癌组织中表达

采用ＳＰ免疫组化法对５２例食管鳞状细胞癌和３０例食管粘膜慢性炎（对照组）进行高危ＨＰＶ１６、１８Ｅ_６和ｐ２１ｒａｓ、ｐ５３癌基因产物的检测。结果表示：鳞癌组中Ｅ_６的阳性率为６７．３１％，与对照组相比差异有极显著性（Ｐ＜０．００１），其中Ｅ_６与ｐ５３呈双阳性者为５５．７７％（２９／５２）、８９．６６％（２６／２９），显示两者阳性着色出现在部分相同区域同一癌细胞核内（似表明Ｅ_６可与ｐ５３结合形成复合物从而导致野生型ｐ５３的降解）。本组ｐ２１ｒａｓ与ｐ５３、ｐ５３与Ｅ_６的阳性表达均具相关性（Ｐ＜０．０５）。提出ＨＰＶ１６、１８感染与本地区食管癌病因学密切相关，Ｅ_６抗体是诊断ＨＰＶ１６、１８感染的良好标记。     

胃癌及其癌前病变中细胞凋亡及其调控基因的表达

目的:通过观察胃癌及其癌前病变中细胞凋亡及其调控基因p53、bcl-2、c-myc的表达,探讨其在胃癌恶性转化进程中的作用。方法:利用DNA末端标记技术(TdT-mediateddUTP-biotinnickendlabeling,TUNEL法)和免疫组织化学(streptavidin/peroxidase,S-P法),原位观察了46例胃癌、20例癌前病变、24例正常粘膜中的凋亡细胞和p53、bcl-2、c-myc的表达。结果:癌前病变和胃癌中凋亡指数显著高于正常粘膜(P＜0.01),癌前病变组高于胃癌组(P＜0.01)。p53、bcl-2、c-myc蛋白在胃癌中阳性率分别为60.9%、67.4%、73.2%,均高于正常粘膜组(P＜0.01);在癌前病变中3种蛋白阳性表达率分别为40%、95%、58.8%(P＜0.01)。胃癌中p53、bcl-2蛋白阳性细胞凋亡指数分别低于阴性组(P＜0.05),c-myc蛋白阳性组细胞凋亡指数高于阴性组(P＜0.01)。结论:细胞凋亡调控异常在胃癌发生中可能起重要作用。p53、bcl-2蛋白分别抑制细胞凋亡,c-myc蛋白在胃癌中促进细胞凋亡。     

Progression of rat embryo fibroblast cells immortalized with transforming genes of human papillomavirus type 16.

To clarify the mechanism of cell transformation by human papillomavirus type 16 (HPV16), we constructed recombinant murine retroviruses containing various subgenomic fragments of the HPV16 early region and examined their abilities to transform rat fibroblasts in primary culture. The E7 ORF, but not the E6 ORF, immortalized cells in primary culture, but the recombinant retrovirus containing both the E6 and E7 ORFs did not transform them. However, after long-term cultivation of cells immortalized by E6 and E7 ORFs, some cells became transformed. During this progression, the amounts of viral mRNA and E7 protein did not change and virus rescued from progressed cells could not transform cells in primary culture, suggesting that some changes in cellular genes, but not viral genes, cause malignant progression of immortalized cells. During this process, the expression of c-K-ras mRNA and its product increased but that of c-myc mRNA did not.     

Molecular characterization of primary mediastinal B cell lymphoma.

Primary mediastinal B cell lymphoma (PMBL) is a diffuse large B cell lymphoma (DLCL) postulated to arise from noncirculating thymic B lymphocytes. Because of its distinctive clinical and morphological features and putative unique cellular origin, PMBL is generally considered a distinct clinicopathological entity. Little is known, however, about the molecular characteristics of PMBL. Therefore, we analyzed 16 PMBLs for molecular alterations involving the bcl-1, bcl-2, bcl-6, c-myc, H-ras, K-ras, N-ras, and p53 genes and for Epstein-Barr virus infection, which are commonly involved in lymphoid neoplasia. Employing a combination of Southern blotting and/or polymerase chain reaction and single-strand conformation polymorphism assays, we detected genetic alterations in 7 of the 16 (44%) PMBLs. Whereas the bcl-6 gene is rearranged in up to 45% of DLCLs, rearrangement of the bcl-6 gene was detected in only 1 of these 16 (6%) PMBLS. Point mutations of the 5' noncoding region of the c-myc gene were demonstrated in 3 other cases (19%), although c-myc gene rearrangements were not seen by Southern blotting. Missense point mutations of the p53 gene were identified in 3 additional PMBLs (19%). Alterations of the bcl-1, bcl-2, or ras genes and evidence of Epstein-Barr virus infection were not observed. In conclusion, a variety of molecular lesions occur in PMBLs and may be involved in their pathogenesis. This molecular genetic pattern bears little resemblance to that known for other B cell malignancies, including DLCL. In particular, the infrequent occurrence of bcl-6 gene rearrangement in PMBLs distinguishes them from other DLCLs of B cell origin, suggesting that PMBLs do not represent a distinct subtype of DLCL.     

Changes in retinoblastoma gene expression during cervical cancer progression

The role of tumour suppressor genes in the development of human cancers has been studied extensively. In viral carcinogenesis, the inactivation of suppressor proteins such as retinoblastoma (pRb) and p53, and cellular oncogenes overexpression, such as c-myc, has been the subject of a number of investigations. In uterine-cervix carcinomas, where high-risk human papillomavirus (HPV) plays an important role, pRb and p53 are inactivated by E7 and E6 viral oncoproteins, respectively. However, little is known about the in situ expression of some of these proteins in pre-malignant and malignant cervical tissues. On the other hand, it has also been demonstrated that c-myc is involved in cervical carcinogenesis, and that pRb participates in the control of c-myc gene expression. By using immunostaining techniques, we investigated pRb immunodetection pattern in normal tissues, squamous intraepithelial lesions (SILs) and invasive carcinomas from the uterine cervix. Our data show low pRb detection in both normal cervical tissue and invasive lesions, but a higher expression in SILs. C-Myc protein was observed in most of the cellular nuclei of the invasive lesions, while in SILs was low. These findings indicate a heterogeneous pRb immunostaining during the different stages of cervical carcinogenesis, and suggest that this staining pattern could be a common feature implicated in the pathogenesis of uterine-cervix carcinoma.     

胃癌及胃液中p53、ras基因突变与临床病理的关系

目的：探讨胃良性病变向恶性转化过程中p53、ras基因突变的规律，并分析胃癌无损伤基因检测的可行性。方法：应用PCR－SSCP及免疫组织化学方法对比研究。结果：异型增生p53基因突变率10％（3／30）、ras基因突变率10％（3／30）、ras基因突变率16．7％（5／30）（二者总突变率26．7％）；早期胃癌p53基因突变率35％（7／20）、ras基因突变率60％（12／20）（二者总突变率85％，其中2例重复突变）； 中晚期胃癌p53基因突变率60％（18／30）、ras基因突变率43．3％（13／30）（二者总突变率90％，其中4例重复突变）；胃息肉ras基因突变仅1／10。30例胃溃疡边缘正常黏膜均未发现p53、ras基因突变。p53基因突变的25例胃癌的胃液中其相应的突变率32％（8／25）。19例胃癌患者的胃液中9例有ras基因突变47．1％（9／19）。异型增生p53蛋白过度表达阳性率13．3％（4／30),p^21ras蛋白阳性率16．7％（5／30）。胃癌p53蛋白阳性率56％（28／50），p^21ras蛋白阳性率60％（30／50）。正常胃黏膜上皮、溃疡边缘正常黏膜及胃息肉均呈p53及ras蛋白阴性表达。结论：胃癌的发生发展与癌基因ras与抑癌基因p53的突变有关，且两种基因同时检测，可覆盖绝大多数胃癌病例，提高了本项技术的可靠性，提供了胃癌无损伤基因检测的可行性的实验证据。     

Cellular steady-state levels of "high risk" but not "low risk" human papillomavirus (HPV) E6 proteins are increased by inhibition of proteasome-dependent degradation independent of their p53- and E6AP-binding capabilities

The group of mucosal epithelia-infecting human papillomaviruses (HPV) can be subdivided in "low" and "high risk" HPV types. Both types induce benign neoplasia (condyloma), but only the infection with a "high risk" HPV type is causally associated with an increased risk of developing anogenital tumors. The oncogenic potential of high risk HPVs resides at least partially in the viral E6 protein. The E6 protein targets the cellular p53 protein for proteasome-dependent degradation, which is associated with the immortalizing and transforming functions of these viruses. Recently the E6-dependent proteasome-mediated destabilization of additional cellular proteins (E6TP1, c-myc, Bak, hMCM7, human scribble, E6AP, MAGI-1) has been described, but the cellular mechanisms controlling the viral E6 protein stability itself have been so far not analyzed. In this study, we transiently expressed the E6 genes of the high risk HPV type 16, the low risk HPV types 6a and 11, and the cutaneous epithelia-infecting HPV types 5 and 8 from a eucaryotic expression vector and compared the cellular steady-state levels of the expressed E6 proteins. We demonstrated that the high risk HPV 16 E6 protein possesses the lowest steady-state level in comparison to the low risk HPV type E6 proteins and the cutaneous epithelia-infecting HPV type E6 proteins. Inhibition of cellular proteasome-dependent protein degradation led to an increase in steady-state levels of high risk but not of low risk E6 proteins. Analysis of functionally deficient HPV 16 E6 proteins in p53 null- and p53 wild-type-expressing cell lines revealed that the cellular steady-state level of this protein is influenced neither by its p53- nor its E6AP-binding abilities.     

Study on the metastatic mechanisms of human giant-cell lung carcinoma comparison between the strains C and D

The biologic characteristics of the two human giant-cell lung carcinoma strains with high (strain D) and low metastatic potential (strain C) were studied, including karyotype of chromosome, intracellular free calcium ([Ca2+]i), morphologic changes of cell surface and the expression of nm23-H1, p53, ras, c-myc, c-erbB2, bcl-2 genes and PCNA. The correlation between different biologic features and the metastatic potential of the two strains was analyzed. We found: 1) Both strains had the karyotypic abnormality of -13, -14, -15, +20, +21 with seven same marker chromosomes. Only strain D had the karyotypic abnormality of +7, -17, -18, +X, 7p+; 2) [Ca2+]i of the strain C (984.7 +/- 573.8) and D (517.6 +/- 216.6) was significantly different (p < 0.05). The amplitude of intracellular calcium oscillations of strain C was lower than the one of strain D; 3) strain C had more villous-like protrusions on the cell surface, whereas strain D had more bubble-like protrusions; 4) The expression of nm23-H1 and p53 protein of strain C was all higher than that of strain D. The expression of PCNA of strain C was lower than strain D; 5) nm23-H1 mRNA levels of strain C was lower than that of strain D. We consider that the karyotype of chromosomes, intracellular free calcium, the structure of cell membrane and the expression of nm23-H1 gene, p53 gene, PCNA could be closely related to the metastatic potential of human giant-cell lung carcinoma. They could be used as the sign for judging whether the tumor will metastasize in clinical practice as well as in judging the prognoses of patients.     

Apoptosis is associated with atypical or malignant change in meningiomas. An in situ labelling and immunohistochemical study

Aims : Although necrosis is an important phenomenon with implications for grading and prognostication in meningiomas, the alternate form of cell death, apoptosis, has not been extensively studied. In this series, we aimed to determine whether apoptosis in meningiomas correlated with histological types and grading. We also looked for a relationship between expression of apoptosis-related genes bcl-2 , p53 , c-myc and apoptosis in meningiomas.  

Methods and results

Fifty-one meningiomas of diverse histological subtypes and grades were investigated with in-situ end-labelling of DNA fragments as well as immunohistochemical analysis of three apoptosis-related genes: p53 , bcl-2 and c-myc . Our results showed that the apoptosis index was significantly higher in high-grade meningiomas (0.12%, n  = 12) in than the benign meningiomas (0.023%, n  = 39) ( P  = 0.001) but there was no difference among the different histological subtypes of the benign meningiomas ( P  = 0.125). There is no obvious relationship between p53, bcl-2 and c-myc staining and apoptosis index in this group of meningiomas.  

Conclusion

We conclude that apoptosis is an important phenomenon in meningiomas and that it is associated with atypical or malignant changes in meningiomas. Apoptosis in meningiomas has no clearcut relationship with expression of p53 , bcl-2 and c-myc .     

肝内胆管细胞癌细胞凋亡相关基因研究进展

细胞凋亡是由多基因调控所引起的细胞主动死亡的过程,肿瘤是细胞凋亡异常疾病,与肝内胆管细胞癌细胞凋亡相关的基因有p53、bcl-2、ras、cycin D1、p16、p27、survivin、c-myc、mdm-2等,它们与肝内胆管细胞癌的发生、发展、治疗和预后关系密切.