共查询到20条相似文献,搜索用时 14 毫秒
1.
Objective: To investigate the relationship between telomere length and radiosensitivity in various human cancer cell lines with the expectation to find a valid and common predictor of radiosensitivity for different cancers. Methods: Eight human cancer cell lines were used, including five human breast cancer cell lines (ZR-75-30, MCF-7, MDA-MB-435S, T-47-D, F539-1590), two human larynx squamous carcinoma cell lines (Hep-2 and Hep-2R) and a human malignant glioma cell line (U251). Among them, the radioresistant cell line Hep-2R was isolated and established from a radiosensitive human larynx squamous carcinoma cell line Hep-2 by our center. The radiobiological characteristics of the eight lines were analyzed by the method of colony-forming assay and the radiosensitivity parameters were calculated. Telomere length was analyzed by TRF (mean Telomere Restriction Fragments) length assay. Results: The radioresistance of Hep-2R cell line proved to be stable in long-term passaged cultures as well as in frozen samples. Radiosensitivity parameters are different among those lines. The SF2 values of Hep-2 and U251 are 0.4148 and 0.7520, respectively; The SF2 values of breast cancer cell lines are between those of Hep-2 and U251. The TRF of Hep-2R is 11.12Kb, longer than three times that of its parental counterpart. There is a positive correlation both between SF2 and TRF (r=-0.786, P〈0.05), and between Do and TRF (r=0.905, P〈0.01). Conclusion: It is concluded that radiosensitivity and telomere length (TRF) are negatively correlated, TRF could be a valid predictor for radiosensitivity. 相似文献
2.
K Maebayashi N Mitsuhashi T Takahashi H Sakurai H Niibe 《International journal of radiation oncology, biology, physics》1999,44(3):677-682
PURPOSE: We reported that two established rat yolk sac tumor cell lines differ in their radiosensitivity by 1.7 fold, and the variation is most likely manifested by the differences seen in their apoptotic response. We investigated the relationship between radiosensitivity and p53 in these cell lines. METHODS AND MATERIALS: We assessed the status of p53 in cell lines by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequence analysis, and also analyzed protein expression of p53, p21, and bax as a function of time after irradiation to determine the signal transduction for p53 by immunoblotting. RESULTS: A band shift was observed only in exon 7 for the radioresistant NMT-1R cells and no band shift was detected for the radiosensitive NMT-1 cells. A band shift was confirmed also at the mRNA level. Exon 7 of p53 DNA showed a three base substitution of DNA at codon 267 to 268. Expression of p53, p21, and bax proteins in NMT-1R cells did not change after 10 Gy irradiation; however, in NMT-1 cells, the expression of these proteins was increased from 1-12 h after irradiation. CONCLUSION: A loss of p53 function by radiation-induced mutation of p53 decreased the radiosensitivity in these cell lines. 相似文献
3.
抑癌基因p53对人胃癌细胞系放射敏感性的作用 总被引:17,自引:0,他引:17
目的评价野生型抑癌基因(正常)p53对人胃癌细胞系放射敏感性的控制作用。方法用流式细胞仪分析4Gy照射后8和24小时4种不同p53状态的人胃癌细胞系细胞周期分布和凋亡的反应。以4Gy细胞存活份数和10Gy照射后的肿瘤生长曲线比较4种细胞的放射敏感性。结果照射4Gy后8小时和24小时的p53正常的BGC823细胞出现强烈的G1期阻滞(分别占原细胞总数的67.9%和61.1%),比无照射的该细胞G1期比例有显著的增高(P<0.05),并出现明显的预示凋亡的亚G1峰(SubG1),凋亡细胞比例分别达13.0%和15.3%;同样条件下其他3种p53异常的细胞G1期比例没有显著的变化(P>0.05),都没有出现亚G1峰,凋亡细胞比例均为0.0%。p53正常的BGC823细胞4Gy的存活份数明显低于其它3种细胞(P<0.05);且细胞移植肿瘤10Gy照射后比其它3种的生长受到更明显抑制(P<0.05)。结论以上的结果证实了野生型p53基因促进了照射后肿瘤细胞的G1期阻滞和凋亡,从而明显地提高肿瘤细胞的放射敏感性。 相似文献
4.
R A Metcalf J A Welsh W P Bennett M B Seddon T A Lehman K Pelin K Linnainmaa L Tammilehto K Mattson B I Gerwin 《Cancer research》1992,52(9):2610-2615
Twenty cell lines from 17 individuals with malignant mesothelioma have been examined for p53 alterations by direct sequencing of genomic DNA, by evaluation of mRNA expression levels, and by immunocytochemical analysis of p53 protein expression in comparison with normal human pleural mesothelial cells. The results of this study show p53 abnormalities in cell lines from 3 individuals. These include 2 point mutations and one null cell line. Interestingly, while both cell lines with point mutations exhibit high levels of p53 protein, normal mesothelial cells as well as 12 of the mesotheliomas evaluated express low but significant levels. In addition, sequencing of K-ras at codons 12, 13, and 61 reveals wild-type sequence in all 20 mesothelioma cell lines. The capacity to induce tumors in athymic nude mice did not correlate with the presence of a p53 mutation or elevated p53 protein levels. These data suggest that neither p53 alteration nor K-ras activation constitutes a critical step in the development of human mesothelioma. 相似文献
5.
The radiation response of 10 human tumour cell lines, eight of them established in our Institute, was analysed. Single dose acute survival curves were constructed and fitted with the linear-quadratic (LQ) model. The mean inactivation dose (D) was also calculated, together with D(o) and n. In order to measure both split-dose recovery and delayed plating recovery of plateau-phase cells, confluent cultures were subjected to two doses of 2 Gy 24 h apart, and plated 24 h later, simulating clinical fractionation. Survival of these cells (S2 x 2) was compared to that following 4 Gy given to cells plated at low density and an overall recovery factor (RF) was derived, including both types of recovery. S2 x 2 and RF were compared to the intrinsic radiosensitivity parameters. The three melanoma cell lines differed in radiation response, and the three squamous cell carcinoma cell lines were rather radioresistant. The neuroblastoma cell line was highly sensitive, yet it expressed the highest beta and the highest RF. Using a non-parametric correlation test, S2 x 2 was found to be related to D, whereas RF was not related to the radiosensitivity parameters. However, the two cell lines with the lowest D and the lowest S2 expressed the highest RF. These results suggest that radiosensitive cell lines may have a considerable capacity to recover if confluent cultures are exposed to fractionated irradiation. The overall recovery factor (RF) used here is proposed as a useful measure of cellular recovery. 相似文献
6.
P. De Feudis D. Debernardis P. Beccaglia M. Valenti E. Graniela Sir?? D. Arzani S. Stanzione S. Parodi M. D'Incalci P. Russo M. Broggini 《British journal of cancer》1997,76(4):474-479
Nine human ovarian cancer cell lines that express wild-type (wt) or mutated (mut) p53 were used to evaluate the cytotoxicity induced by cisplatin (DDP). The concentrations inhibiting the growth by 50% (IC50) were calculated for each cell line, and no differences were found between cells expressing wt p53 and mut p53. Using, for each cell line, the DDP IC50, we found that these concentrations were able to induce an increase in p53 levels in all four wt-p53-expressing cell lines and in one out of five mut-p53-expressing cell lines. WAF1 and GADD45 mRNAs were also increased by DDP treatment, independently of the presence of a wt p53. Bax levels were only marginally affected by DDP, and this was observed in both wt-p53- and mut-p53-expressing cells. DDP-induced apoptosis was evident 72 h after treatment, and the percentage of cells undergoing apoptosis was slightly higher for wt-p53-expressing cells. However, at doses near the IC50, the percentage of apoptotic cells was less than 20% in all the cell lines investigated. We conclude that the presence of wt p53 is not a determinant for the cytotoxicity induced by DDP in human ovarian cancer cell lines. 相似文献
7.
EFFECT OF ADENOVIRUS—MEDIATED p53 GENE TRANSFER ON APOPTOSIS AND RADIOSENSITIVITY OF HUMAN 总被引:1,自引:0,他引:1
To evaluate the effect of adenovirus-mediated p53 gene(Adp53) on apoptosis and radiosensitivity of human gastric carcinoma cell lines.Methods:Recombinant adenovirus expressing wild-type p53 lines with different p53 genetic status.p53 protein expression was detected by immunohistochemistry assay and western blot assay.Cell survival was assessed using a clonogenic assay.TUNEL assay was used in determination of apoptosis.Four human gastric carcinoma cells infected with Adp53 were irradiated with 4Gy and cell cycle distribution and Sub-G1 peak were assayed by flow cytometry.Results:G2/M arrest,apoptosis and inhibition of tumor cell proliferation were induced by infection at Adp53 at 100 MOI which caused high transfer rate of wild-type p53 and strong expression of p53 protein in four human gastric carcinoma cells.The radio-enhancement ratio of Adp53 at 4Gy were3.0 for W cell,3.6 for M cell,2.2 for neo cell and 2.5 for 823 cell in vitro.Conclusion :This study demonstrated that Adp53 transfer increased cellular apoptosis and radiosensitivity of human gastric carcinoma cell lines in vitro independently on cellular intrinsic p53 status thus supporting the combination of p53 gene therapy with radiotherapy in clinical trials. 相似文献
8.
Mutational analysis of p73 and p53 in human cancer cell lines. 总被引:12,自引:0,他引:12
H Yoshikawa M Nagashima M A Khan M G McMenamin K Hagiwara C C Harris 《Oncogene》1999,18(22):3415-3421
p73 is a candidate tumor suppressor gene with substantial DNA and protein homology to the p53 tumor suppressor gene. We have investigated two hypotheses: (a) p73 is mutated in diverse types of human cancer, and (b) p73 is functionally redundant with p53 in carcinogenesis so that mutations would be exclusive in these two genes. The entire coding region and intronic splice junctions of p73 were examined in 54 cancer cell lines. Three lung cancer cell lines contained mutations that affected the amino acid sequence. One amino acid substitution was in a region with homology to the specific DNA binding region of p53 and two microdeletions were outside the region of homology. Two of the cell lines with p73 mutations also carried p53 mutations. Although our results are inconsistent with the two hypotheses tested, p73 mutations may contribute infrequently to the molecular pathogenesis of human lung cancer. 相似文献
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Stefan Kraiss Regina Espig Ulrich Vetter Wolfgang Hartmann Mathias Montenarh 《Leukemia research》1990,14(11-12):1041-1051
The cell-encoded p53 antigen seems to be tightly associated with various human malignancies. We have analyzed biochemical properties of p53 in two different cell lines derived from patients with ALL or ANLL. p53 was found in elevated levels in both leukemic cell lines compared to unstimulated or stimulated normal lymphocytes. High levels of p53 in these cell lines are due to an extended stability of p53 protein rather than to different rates of synthesis. p53 from both cell lines formed low- and high-molecular weight oligomers which revealed that p53 exists in a heterogenous population in these tumor cells. The presence of immunologically different subsets of p53 was demonstrated by sequential immunoprecipitation experiments with different p53 specific monoclonal antibodies. Our results showed structural and immunological variabilities of p53 in cell lines derived from human tumors and may thus provide an insight into the role p53 may play in human malignancies. 相似文献
11.
p53 Mutations in human immortalized epithelial cell lines 总被引:22,自引:2,他引:22
Lehman Teresa A.; Modali Rama; Boukamp Petra; Stanek Julie; Bennett William P.; Welsh Judith A.; Metcalf Robert A.; Stampfer Martha R.; Fusenig Norbert; Rogan Eileen M.; Harris Curtis C. 《Carcinogenesis》1993,14(5):833-839
Although rodent cells have been immortalized following transfectionwith a mutant p53 gene, the role of p53 in the immortalizationof human cells is unknown. Therefore, human epithelial celllines were examined for p53 mutations in exons 49 whichinclude the evolutionarily conserved regions. A spontaneouslyimmortalized skin keratinocyte cell line, HaCat, and three ras-transfectedclones, have a p53 mutational spectrum that is typical of ultravioletlight induced mutations. A normal finite lifespan cell strain(184) and two benzo[a]pyrene immortalized mammary epithelialcell lines derived from 184 (184A1 and 184B5) contain wild typep53 sequences in exons 49, although elevated levels ofnuclear p53 indicate an alteration in the stability of the normallytransient protein. Wild type p53 was found in human bronchial,esophageal and hepatic epithelial cells immortalized by SV40T antigen gene and human renal epithelial cells immortalizedby adenovirus 5. BEAS-2B, an SV40 T antigen immortalized bronchialepithelial cell line and two subclones, have a germline polymorphismat codon 47. Inactivation of p53 by mechanisms such as mutationor complexing with proteins of DNA tumor viruses appears tobe important in the immortalization of human epithelial cells. 相似文献
12.
Herman Burger Kees Nooter Antonius W.M. Boersma Christine J. Kortland Gerrit Stoter 《International journal of cancer. Journal international du cancer》1997,73(4):592-599
We investigated the role of p53 and of the Bcl-2 family proteins in the apoptotic response of a panel of testicular tumour cell lines (NT2, NCCIT, S2 and 2102 EP). The p53 gene status and the capacity of the p53 protein to transactivate the p21/WAF/CIP gene were determined, and we examined the correlation between p53 status and the susceptibility to cisplatin-induced apoptosis. In contrast to wild-type p53-containing NT2 and 2102 EP cells, NCCIT (mutant p53) and S2 (no p53 protein) cells were shown to be p53-transactivation defective. However, NCCIT and S2 cells with non-functional p53 were readily triggered into apoptosis by cisplatin, whereas p53-transactivation competent 2102 EP cells failed to undergo cisplatin-induced apoptosis. The defective apoptotic pathway in 2102 EP cells was reflected by a 4-fold decreased sensitivity to cisplatin in the MTT assay. We further demonstrated that the p53-independent differential cisplatin sensitivity among the testicular germ cell tumour (TGCT) cell lines was not due to differences in cellular cisplatin accumulation or DNA platination. The pattern of endogenous expression levels of Bax, Bcl-2, Bcl-x and Bak, which was not modulated by cisplatin treatment, demonstrated that these Bcl-2 family proteins are not involved in drug-induced apoptosis in the TGCT cell lines. Our results suggest a lack of correlation between cisplatin-induced apoptosis, p53 status and expression of Bcl-2 family proteins in our panel of TGCT cell lines. We conclude that the cisplatin-induced apoptotic pathway in TGCT cell lines might be p53-independent and is probably not associated with differences in the Bcl-2/Bax rheostat. Int. J. Cancer 73:592–599, 1997. © 1997 Wiley-Liss, Inc. 相似文献
13.
Y. Yaginuma T. Yamashita N. Takuma H. Katayama M. Ishikawa 《British journal of cancer》1995,71(1):9-12
In the present study, we analysed human choriocarcinoma cell lines for abnormalities in the tumour-suppressor gene p53 by Southern blotting, Northern blotting, non-radioisotopic single-stranded conformational polymorphism (SSCP) and complementary DNA sequencing. In all cell lines (Bewo, GCH-1, GCH-2, SCH, JAR, JEG-3, NUC-1 and HCCM-5), no p53 gene abnormality was detected by using Southern blotting. p53 mRNA of the expected size was detected in all cell lines tested by Northern blotting. SSCP analysis revealed abnormalities of p53 cDNA in the SCH cell line. Sequencing analysis of the entire coding region of the p53 gene revealed that both alleles were expressed in the JEG-3 cell line, and one of the alleles contained a point mutation (G to T) in codon 167 (Gln to His). In the NUC-1 cell line both alleles were point mutated. One allele had a point mutation (A to T) that resulted in a codon 17 change (Glu to Asp), and another had a point mutation (A to T) that caused a codon 24 change (Lys to Asn). In the SCH cell line, AGG was inserted between codon 249 and 250; this insertion resulted in an abnormal structure of the p53 protein. In three out of eight human choriocarcinoma cell lines, a p53 gene abnormality was detected. Therefore our data demonstrate that p53 gene abnormalities are associated with choriocarcinoma cell lines. 相似文献
14.
Telomeres play an important role in maintaining chromosomal stability and are often shortened in transformed cells. p53 is the most commonly mutated gene in cancers and its status is thought to reflect the level of genomic stability. We measured telomeric length by Southern blot analysis in cells from cancer-prone syndromes and in selected cancer cells with altered p53 status. Mean telomeric lengths in the cancer-prone syndromes Li-Fraumeni syndrome, Fanconi's anemia, and ataxia telangiectasia, were shorter in the affected individuals than in their unaffected parents. We also found that altered p53 expression in selected cancer cell model systems may be associated with shortened telomeric length, but did not appear to be associated with significant alterations in telomerase activity. 相似文献
15.
Li-Qun Jia Motonobu Osada Chikashi Ishioka Makio Gamo Shuntaro Ikawa Takao Suzuki Hideki Shimodaira Tomohito Niitani Toshio Kudo Mitoshi Akiyama Narimiti Kimura Mitsuyoshi Matsuo Hiroshi Mizusawa Noriho Tanaka Hideki Koyama Masayoshi Namba Ryunosuke Kanamaru Toshio Kuroki 《Molecular carcinogenesis》1997,19(4):243-253
We have screened the p53 status of 156 human cell lines, including 142 tumor cell lines from 27 different tumor types and 14 cell lines from normal tissues by using functional analysis of separated alleles in yeast. This assay enables us to score wild-type p53 expression on the basis of the ability of expressed p53 to transactivate the reporter gene HIS3 via the p53-responsive GAL1 promoter in Saccharomyces cerevisiae. Of 142 tumor cell lines, at least 104 lines (73.2%) were found to express the mutated p53 gene: 94 lines (66.2%) were mutated in both alleles, three lines (2.1%) were heterozygous, and no p53 cDNA was amplified from seven lines (4.9%). Of the 14 cell lines originating from normal tissues, all the transformed or immortalized cell lines expressed mutant p53 only. Yeast cells expressing mutant p53 derived from 94 cell lines were analyzed for temperature-sensitive growth. p53 cDNA from eight cell lines showed p53-dependent temperature-sensitive growth, growing at 30°C but not at 37°C. Four temperature-sensitive p53 mutations were isolated: CAT→CGT at codon 214 (H214R), TAC→TGC at codon 234 (Y234C), GTG→ATG at codon 272 (V272M), and GAG→AAG (E285K). Functionally wild-type p53 was detected in 38 tumor cell lines (26.8%) and all of the diploid fibroblasts at early and late population doubling levels. These results strongly support the previous findings that p53 inactivation is one of the most frequent genetic events that occurs during carcinogenesis and immortalization. Mol. Carcinog. 19:243–253, 1997. © 1997 Wiley-Liss, Inc. 相似文献
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Mutations of the p53 gene in human myeloma cell lines. 总被引:8,自引:0,他引:8
G R Mazars M Portier X G Zhang M Jourdan R Bataille C Theillet B Klein 《Oncogene》1992,7(5):1015-1018
Mutations affecting the p53 gene have been found associated with many human malignancies, but little is as yet known about multiple myeloma. We investigated p53 gene alterations in 10 human myeloma cell lines (HMCL), half of these being dependent upon exogenous interleukin 6 (IL-6) for in vitro growth, similar to freshly explanted myeloma cells. Using a polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) approach, eight of the 10 HMCL were found to bear a mutated p53 gene. All the mutations were single base substitutions with a predominance of G:C to A:T transitions. There was no apparent relation between the presence of a mutation and IL-6 requirement of the cell line. Interestingly, in two cell lines (XG-2 and XG-4) the SSCP pattern showed the presence of both the wild-type and the mutated allele and, upon reverse PCR on RNA, both alleles were found to be concomitantly expressed at the RNA level. Moreover, three freshly explanted tumor samples had the same p53 gene status (mutated versus wild type) as the HMCL that were derived from them. These results show that p53 mutations are frequent in HMCL. Although no apparent relation could be evidenced with the loss of exogenous IL-6 requirement, it may prove interesting to investigate further potential relations between the presence of a mutated p53 allele and gradual autonomy for cell growth. 相似文献
18.
The effect of the maturation-inducing polar solvent, hexamethylene bisacetamide (HMBA), on the radiosensitivity of two human tumour cell lines (clone A, a colon carcinoma; and EJ, a bladder carcinoma) was investigated. Exposure of clone A or EJ cells to HMBA resulted in a concentration-dependent increase in doubling time, a decreased plating efficiency and changes in cell morphology, which are consistent with the formation of a better-differentiated phenotype. Growth of clone A cells in 2 or 3 mM HMBA, followed by irradiation and plating into HMBA-free medium, resulted in a significant enhancement in radiosensitivity, as determined by colony-forming ability. A similar increase in radiosensitivity was detected for EJ cells; however, for these cells a concentration of 7 mM HMBA was required. The increased radiosensitivity caused by HMBA was observed primarily in the low-dose, shoulder region of the gamma-ray cell survival curves for both cell lines, which is reflected by an increase in the alpha component of the survival curve with essentially no effect on beta. These data indicate that HMBA can radiosensitise human tumour cells at concentrations and for exposure periods that can be achieved in the clinic. 相似文献
19.
目的 通过对ATM蛋白在不同肺癌细胞株中表达差异与放射敏感性关系的研究,为下一步研究打下基础。方法利用细胞集落形成实验研究肺癌细胞株A549、NCI—H446的放射敏感性差异,并结合免疫荧光实验和激光共聚焦扫描(LSCM)技术来探讨两细胞株中ATM蛋白的表达差异与放射敏感性之间的关系。结果集落形成实验中,在接受2、4、6、8Gy剂量照射时,A549和NCI—H446两肺癌细胞株的存活分数分别为81.0%、32.4%、12.0%、3.5%和52.4%、17.0%、3.2%、0.7%。ATM蛋白定位于细胞浆和胞核;利用LSCM分析两细胞株中ATM蛋白的表达差异,A549细胞ATM蛋白荧光强度(71.188+13.379)较NCI-H446细胞(47.478±19.032)明显增强(P〈0.0001),有统计学意义。结论两肺癌细胞株A549和NCI-H446具有放射敏感性差异,ATM蛋白在两细胞株中的表达亦有差异显著性,表明其表达量可能与放射敏感性呈负相关。 相似文献
20.
Nouri AM Cannell H Dagini B Dabare AA Habib N Fowler CG 《European journal of cancer (Oxford, England : 1990)》2000,36(14):1853-1862
In this investigation the profile of p53 and epidermal growth factor receptor (EGFR) expression in tumour tissue biopsies of transitional cell carcinoma of bladder (TCC) and of oral-pharyngeal carcinoma (OP) were compared using an immunocytochemical staining method. In addition, various techniques including sodium dodecyl sulphate-polyacrylamide gel elecrophoresis (SDS-PAGE), colorimetric assay and gene transfection were used to investigate the influence of p53 on the behaviour of human tumour cell lines in vitro. The results showed that: (a) p53 was detectable in more than 45% of cases in both tumour types, although the profile and intensity of expression differed. (b) Concomitant strong expression of EGFR and p53 for TCC and OP was 21% and 38% (P>0.05%), respectively. (c) Treatment of tumour cells by either gamma radiation or by cisplatin resulted in the induction of p53 independent of the origin of the tumour. (d) Susceptibility of two cell lines, one with and one without constitutive expression of p53 showed that the expressing cells were more sensitive to gamma radiation (the percentage inhibition at 250 cGy was 57% versus -15%, P<0.01), and also cisplatin (the percentage inhibition at 1 microgram/ml was 71.0+/-6.0 versus 2.6+/-7.0, P<0.001). (e) Transfection of wild-type TP53 gene into a bladder tumour cell line resulted in a rapid cell apoptosis (by as much as 90%) whereas cells receiving mutated TP53 survived. A similar frequency of TP53 mutation in TCCs and OPs was observed. In addition, the pattern of p53 expression within the squamous type of TCC was similar to that in OPs. If the data from the in vitro studies could be translated into an in vivo setting, one could envisage a situation where the introduction of wild-type TP53 gene by gene transfection into tumour cells (independent of their TP53 gene mutational status), would prove to be beneficial. If the cellular TP53 gene is mutated, then an introduction of the normal TP53 gene would induce cells to undergo apoptosis. Alternatively, if TP53 is wild-type, then the increased levels of p53 expression would enable the cells to become more susceptible to DNA damaging treatments such as cisplatin or gamma radiation. 相似文献