Epidermal growth factor receptor targeting of replication competent adenovirus enhances cytotoxicity in bladder cancer

PURPOSE: We evaluated the delivery and oncolytic potential of targeted replication competent adenoviruses in bladder cancer lines. MATERIALS AND METHODS: Seven established human bladder cancer tumor lines (5637, SW800, TCCsup, J82, Scaber, T24 and 253J) were studied for the expression of integrins alpha(v)beta3, alpha(v)beta5, Coxsackievirus and adenovirus receptor, epidermal growth factor receptor (EGF-R) and epithelial cell adhesion molecule antigens using flow cytometry analysis. Bispecific single chain Fv fragments were used to target replication deficient luciferase reporter adenovirus to EGF-R (425-s11) or to epithelial cell adhesion molecule (C28-s11) antigens. Moreover, a fiber modified adenovirus targeting alpha(v)-integrins was studied. Replication competent serotype-5 adenoviruses attenuated to replicate specifically in retinoblastoma pRb (Ad5-d24) or p53 deficient (Ad5-d55K) cells were tested in vitro for oncolytic properties. RESULTS: Low to absent Coxsackievirus and adenovirus receptor expression was found in 5 of the 7 tumor lines (SW800, J82, T24, 5637 and Scaber). EGF-R expression was found in all cell lines, whereas elevated epithelial cell adhesion molecule expression was seen in 3 (5637, Scaber and TCCsup), alpha(v)beta3-integrin was found in 1 (Scaber) and alpha(v)beta5-integrin was found in 3 (TCCsup, 253J and T24). EGF-R targeting using 425-s11 improved transgene expression in all cell lines from 2.1 to 12.5 times over nontargeted viruses. Epithelial cell adhesion molecule and integrin targeting was inferior to EGF-R targeting with a maximal increase in transgene expression of 2 times for epithelial cell adhesion molecule in 5637cells and 1.6 times for integrin targeting in T24 cells. Comparison of the wild-type replication competent virus with conditionally replicating adenoviruses (Ad5-d55K and Ad5-d24) showed superior oncolytic activity for the latter 2 in all lines. Furthermore, improved cytotoxicity (29% to 33%) was obtained in 4 of the 7 lines after pre-incubation of Ad5-d24 with 425-s11. CONCLUSIONS: EGF-R directed bispecific single chain antibodies enhance adenovirus mediated transgene expression and oncolysis in bladder cancer lines.     

The growth inhibitory effect of p21 adenovirus on androgen-dependent and -independent human prostate cancer cells

OBJECTIVE: To assess the potential of p21 as a gene therapy treatment for prostate cancer, by introducing p21 into both androgen-dependent (AD) and -independent (AI) human prostate cancer cell lines via a recombinant adenoviral vector, Ad5CMV-p21, carrying human p21 cDNA. MATERIALS AND METHODS: The LNCaP, DU145 and PC-3 human prostate cancer cell lines were cultured and infected with Ad5CMV-p21. Cell growth, cell-cycle progression and tumorigenicity were then assessed by thymidine incorporation into cellular DNA, and cell number, flow cytometry, and tumour growth after inoculating the cells into nude mice. RESULTS: Growth was inhibited in Ad5CMV-p21 viral-infected AD and AI prostate cancer cells. The effects were dose-dependent, regardless of the androgen status of the cell lines. Flow cytometric analysis showed that Ad5CMV-p21 arrested cell-cycle progression at G1/S with no appreciable effect on the levels of apoptotic cells. The tumorigenicity of cancer cells infected with Ad5CMV-p21 was greatly reduced in athymic mice. CONCLUSIONS: These results suggest that Ad5CMV-p21 may be a new therapeutic agent for human prostate cancer gene therapy.     

FUNCTIONAL p53 MUTATION AS A MOLECULAR DETERMINANT OF PACLITAXEL AND GEMCITABINE SUSCEPTIBILITY IN HUMAN BLADDER CANCER

PURPOSE: Paclitaxel and gemcitabine are promising new agents for treatment of human bladder cancer. We determine how the presence or absence of p53 function impacts the cytotoxic effects of these chemotherapeutic agents in human bladder cancer. MATERIALS AND METHODS: The J82 human bladder cancer (TCC) cell line was transfected with a temperature sensitive p53 (tsp53) mutant that functions as mutated p53 at 37C but functions as wild-type (normal) p53 at 32C. Susceptibility of these inducible p53 TCC cells to paclitaxel and gemcitabine induced cytotoxicity was evaluated and kill significance determined between sub-lethal and lethal doses. RESULTS: Significant paclitaxel dose dependent cytotoxicity was observed in J82 TCC cells lacking normal p53 and tsp53 transfected cells at 37C, which was the mutant p53 temperature in transfectants between maximal and minimal kill concentrations for either (p <0.001). Likewise, significant cytotoxicity was observed in parental J82 TCC at 32C (p <0.001), while restoration of p53 function in tsp53 transfected cells on shift to 32C abrogated significant dose dependent cytotoxicity. Gemcitabine caused significant cell death in the cell lines incubated at either temperature and, thus, was equally effective regardless of cellular p53 function (p <0.001, respectively). CONCLUSIONS: Paclitaxel requires functionally mutated p53 to induce cell death in human bladder cells, indicating that it may be more effective against TCC with p53 mutations than against TCC, which lacks p53 abnormalities, while gemcitabine is effective regardless of p53 function. These findings provide a rationale for selecting chemotherapy based on the p53 status of individual bladder cancers.     

Differential involvement of the Fas receptor/ligand system in p53-dependent apoptosis in human prostate cancer cells

BACKGROUND: The objective of this study was to characterize the involvement of the Fas receptor/ligand system in p53-dependent apoptosis in human prostate cancer cells. METHODS: The effects of adenovirus-mediated p53 gene transfer (Ad5CMV-p53) into human prostate cancer LNCaP, DU145, and PC3 cells on their growth, apoptosis and Fas receptor/ligand expression were examined by the MTT assay, DNA fragmentation assay, and Northern blot analysis, respectively. The sensitivity of these cells to an agonistic anti-Fas receptor antibody (CH11) and the effects of an antagonistic anti-Fas ligand antibody (4H9) on Ad5CMV-p53-induced apoptosis were analyzed by the MTT assay and DNA fragmentation assay. RESULTS: Ad5CMV-p53 treatment resulted in substantial growth inhibition, induction of apoptosis and up-regulation of Fas receptor as well as Fas ligand mRNA expression in LNCaP, DU145 and PC3 cells. Despite the abundant expression of Fas receptor in all of these cells, CH11 induced apoptosis only in PC3 cells. Furthermore, 4H9 partially blocked the apoptosis induced by Ad5CMV-p53 in PC3 cells, but not in LNCaP and DU145 cells. CONCLUSIONS: The Fas receptor/ligand system is differentially involved in p53-dependent apoptosis in prostate cancer cells; therefore, reintroduction of wild-type p53 into prostate cancer cells may induce apoptosis through Fas receptor/ligand interaction as well as through an alternative pathway.     

MiR-486-5p enhances cisplatin sensitivity of human muscle-invasive bladder cancer cells by induction of apoptosis and down-regulation of metastatic genes

ObjectivesCisplatin is one of the common chemotherapy drugs for bladder cancer, and resistance to this drug is one of the major obstacles to effective chemotherapy. MicroRNAs (miRNAs) are a category of small noncoding RNAs that can regulate the expression of numerous genes. Recent studies showed that miRNAs can act as a powerful regulator of chemo-sensitivity in cancer cells. Hence, this study aimed to investigate the effects of miRNA-486-5p on cisplatin-sensitivity of different bladder cancer cells.Material and MethodsThe 5637 and EJ138 cancer cells were treated with miRNA-486-5p and cisplatin, individually or in combination.ResultsAfterward, the cytotoxicity effects of these treatments were determined by MTT assay and the increased cisplatin-sensitivity observed in both cell lines, especially, 5637 cells. Moreover, subG1 phase cell cycle arrest, changes in the expression of caspase-9, caspase-3, P53, SIRT1, OLFM4, SMAD2, and Bcl-2 genes and nuclear fragmentation also revealed the induction of apoptosis in all treatments, which increased in combination groups. Also, the combination of miRNA-486-5p with cisplatin significantly down-regulated the expression of migration associated genes including ROCK, CD44, and MMP-9 as compared with cisplatin alone.ConclusionAltogether, these results indicated that the miRNA-486-5p could induce apoptosis and inhibit cell migration ability of the cells. It seems that pre-electroporation of cells with miRNA-486-5p has useful results in the enhancement of cisplatin sensitivity of 5637 and EJ138 cancer cells and this combination may be a promising treatment strategy for bladder cancer therapy.     

Dicoumarol enhances doxorubicin‐induced cytotoxicity in p53 wild‐type urothelial cancer cells through p38 activation

OBJECTIVE

To investigate the effectiveness of a combined treatment of 3–30‐methylene‐bis[4‐hydroxycoumarin] (dicoumarol) with doxorubicin for the treatment of urothelial cancer, as doxorubicin is a common chemotherapeutic agent but its therapeutic efficacy is limited.

MATERIALS AND METHODS

The synergistic effect of dicoumarol with chemotherapeutic agents such as cisplatin, doxorubicin and paclitaxel was evaluated in RT112 urothelial cancer cells. Then, dicoumarol‐mediated enhancement of doxorubicin‐induced cytotoxicity was screened in urothelial cancer cell lines with different p53 statuses or RT112 stable transfectants with a dominant‐negative mutant of p53 (p53DN). To clarify the importance of the modification of p53 function by dicoumarol to enhance doxorubicin toxicity, the change in the p53‐p21 pathway and mitogen‐activated protein kinase (MAPK)‐mitochondria pathway by the combined treatment were elucidated by Western blot analysis. Finally, the effect of p21 knockdown in the susceptibility to doxorubicin was examined with RT112 stable transfectants with short hairpin RNA (shRNA) of p21.

RESULTS

Dicoumarol significantly increased the susceptibility of RT112 cells to cisplatin and doxorubicin, but not to paclitaxel in RT112 cells. Dicoumarol (100 µm ) also enhanced the cytotoxicity of doxorubicin in other bladder cancer cell lines with wild‐type p53 (wt‐p53; three times in 253J and 13 times in KK47), but not in those with mutant‐type p53 (TCCsup, J82 and EJ) or in RT112 p53DN. The combined treatment with dicoumarol suppressed p53/p21 induction by doxorubicin and resulted in sequential p38 MAPK activation, myeloid cell leukaemia 1 suppression and caspase cleavage. The synergistic effect of doxorubicin/dicoumarol was suppressed by the p38 MAPK inhibitor SB202190 and, furthermore, p21 knockdown with shRNA transfection made RT112 cells six times more susceptible to doxorubicin with p38 MAPK activation.

CONCLUSION

These results suggest that concomitant use of dicoumarol could enhance the cytotoxicity of doxorubicin in urothelial cancer cells with wt‐p53 through the p53/p21/p38 MAPK pathways. This combined treatment may provide a new therapeutic option to overcome chemoresistance in bladder cancer.     

Growth inhibitory effect of p21 and p53 containing adenoviruses on transitional cell carcinoma cell lines in vitro and in vivo

Altered p53 expression has been demonstrated in the majority of advanced transitional cell carcinoma (TCC) of the bladder tumors. The objective of this investigation was to examine the effect of the introduction of a p53 or p21^(WAF1/CIP1) adenovirus on the proliferation and apoptosis of various human TCC cell lines in vitro and in vivo. Proliferation was measured by ³H-thymidine incorporation. Apoptosis was measured by DNA fragmentation and bax expression. We also examined the effect of ex vivo introduction of the p21^(WAF1/CIP1) or the p53 gene on growth of the T24 TCC cells and UMUC-3 TCC cells introduced subcutaneously into athymic nude mice. We found that although the effect of the p21-adenovirus on the proliferation of various TCC lines varied with each individual cell line, there was a substantial growth inhibition observed (greater than 80% growth inhibition) in seven of the eight TCC cell lines at the highest viral dosage. In contrast, after 24 h, the highest dosage of the p53-adenovirus produced only a heterogeneous decrease in proliferation compared to the highest dose of the p21^(WAF1/CIP1)-adenovirus (40–90%). In ex vivo experiments, no tumors were found in nude mice injected subcutaneously with either TCC cell line exposed in vitro to the AdSCMV-p21^(WAF1/CIP1) or AdSCMV-p53 viruses before three weeks. There was a threefold decrease in tumor square area at week 5 in the Ad5CMV-p21^(WAF1/CIP1) or Ad5CMV-p53 TCC cells injected mice (p<0.001, p<0.009) compared to either mock or Ad5CMVLacZ TCC bladder tumor cells. These data suggest that significant portion of the effect of altered p53 on TCC phenotype may be mediated through the p21^(WAF1/CIP1) pathway. Thus, the restoration of p21^(WAF1/CIP1) function in this tumor system may be a beneficial therapeutic strategy.     

A comparison of the platinum analogues in bladder cancer cell lines

BACKGROUND: Oxaliplatin is a 3rd generation platinum analogue, which is active in a broad spectrum of tumours. Clinical trials using this drug in bladder cancer are underway, but not yet reported. There are currently no in vitro data regarding oxaliplatin in bladder cancer. Therefore, this study compares the efficacy of oxaliplatin with cisplatin and carboplatin, which are both used widely in this tumour type, in bladder cancer cell lines. METHOD: The efficacy of oxaliplatin, carboplatin and cisplatin were compared in 4 bladder cancer cell lines (5637, J82, HT1197 and 253J). Cell parameters including cell number, viability and apoptosis were assessed after 3 days of drug exposure. The effects of the drugs on the cell cycle were also observed. RESULTS: Overall cisplatin was the most potent at inducing cell death (IC(50) 11.5-70.6 microM). Oxaliplatin was the 2nd most potent drug (IC(50 )15.2-126.3 microM) and carboplatin the least effective (IC(50 )75.4-137.8 microM). Carboplatin was significantly less potent at inducing cell death than the other two drugs in all 4 cell lines. Carboplatin was also inferior at inducing apoptosis in 3 of the 4 cell lines. All three drugs had a similar effect on the cell cycle, causing an initial G2 block. CONCLUSIONS: These data suggest that oxaliplatin is a potent agent in bladder cancer cell lines and is superior to carboplatin in this in vitro setting. It justifies the clinical studies using oxaliplatin that are underway.     

p53 protein transduction therapy: successful targeting and inhibition of the growth of the bladder cancer cells

INTRODUCTION: Virus-mediated gene therapy for bladder cancer has some problems, such as efficiency of gene delivery and safety issues. We have reported that poly-arginine peptide (11R) has the ability to increase protein transduction in cells. Here, we show that p53 protein transduction using 11R is useful for targeting to bladder tumors and suppressing the growth of bladder cancer cells. MATERIALS AND METHODS: An 11R-fused p53 protein (11R-p53) was transduced in bladder cancer cell lines (J82 and T24) to evaluate the anti-tumor effect. Cell viability was assessed by performing the 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST) assay. To investigate whether 11R-p53 enhanced the effect on anti-cancer drug-dependent apoptosis of bladder cancer cells, the cell lines were cotreated with 11R-p53 and cis-diaminedichloroplatinum (CDDP). Apoptotic cells were identified using Hoechst staining. To investigate the efficiency of protein transduction mediated by 11R in bladder tumors in vivo, SCID mice were transplanted with J82 cells in the bladder and 11R-GFP was transurethrally transduced into the bladder. The transduction of 11R-GFP in the tumor was examined by confocal microscopy. RESULTS: 11R-p53 inhibited the growth of both J82 and T24 cells in a dose-dependent manner. The transduction of 11R-p53 enhanced CDDP-dependent induction of apoptosis. Transurethral application of 11R-GFP resulted in transduction of GFP in bladder tumors but not in the normal bladder epithelium or subepithelial tissues. CONCLUSION: The present results suggest that p53 protein transduction therapy may be a promising method for the treatment of bladder cancer.     

LIN28A和LAMP1在膀胱癌细胞系中的表达及意义

目的:探讨LIN28A和LAMP1在膀胱癌细胞系中表达情况,以及两者之间的关系,推测其可能临床意义及对肿瘤进展的影响。方法:采用RT-PCR检测膀胱癌细胞系LIN28A、LIN28B和LAMP1表达,免疫荧光检测LIN28A和LAMP1二者蛋白表达定位;LIN28A敲减后通过qRT-PCR检测LAMP1的mRNA表达变化。结果:5个癌细胞系T24、UM-UC3、J82、5637和SW780和正常移行上皮细胞系SV-HUC-1均表达LIN28A,其中J82也表达LIN28B;5个癌细胞系均表达LAMP1,SV-HUC-1不表达LAMP1;LIN28A和LAMP1蛋白均定位在胞浆;LIN28A敲减后对LAMP1的mRNA表达变化无明显影响,相应蛋白变化需要进一步验证。结论:4个膀胱癌细胞系T24、5637、UM-UC3和SW780可以用于LIN28A与肿瘤相关的机制研究,而J82可用于LIN28B的机制研究。LIN28A对肿瘤细胞和干细胞的调控方面可能具有相似性,敲减后对其靶点mRNA表达量无明显影响,LAMP1蛋白可能对肿瘤细胞侵袭转移具有抑制作用。     

5-氮杂脱氧胞苷与曲古抑菌素A对膀胱癌细胞株ALDH1a2基因表达及凋亡的影响

目的 探讨5-氮杂脱氧胞苷(5-Aza-dC)与曲古抑菌素A(TSA)对膀胱癌细胞中抑癌基因ALDH1a2启动子甲基化状态和基因表达及细胞凋亡的影响.方法 使用5-Aza-dC、TSA处理RT-4、253J、5637、BIU-87和T24后,应用甲基化特异性PCR(MSP)法、逆转录PCR(RT-PCR)法、Western blot法分别检测这5株膀胱癌细胞经药物干预前后ALDH1a2甲基化状态及基因表达情况,应用流式细胞学检测干预前后5株膀胱癌细胞株的凋亡情况.结果 在5株膀胱癌细胞中,ALDH1a2基因表现为高甲基化表达受到抑制,TSA不影响甲基化状态,5-Aza-dC可逆转高甲基化状态并恢复基因表达,联合给予5-Aza-dC和TSA的作用和单独给予5-Aza-dC相似;TSA和5-Aza-dC均可诱导膀胱癌细胞株凋亡,早期凋亡是膀胱癌细胞株死亡的主要方式,5-Aza-dC和TSA有协同作用,3个实验组与对照组比较,差异均有统计学意义(P<0.05).结论 在5株膀胱癌细胞株中,ALDH1a2基因启动子甲基化可能是导致其基因失活的主要原因;5-Aza-dC单独作用和5-Aza-dC及TSA联合应用效果相似,均能恢复基因重新表达进而诱导膀胱癌细胞株的早期凋亡.     

Radiation induces<Emphasis Type="Italic"> p53</Emphasis>-dependent cell apoptosis in bladder cancer cells with wild-type-<Emphasis Type="Italic">p53</Emphasis> but not in<Emphasis Type="Italic"> p53</Emphasis>-mutated bladder cancer cells

Purpose. It has been reported in several studies that the absence in cancer cells of the p53 tumor suppressor gene, mutations of which are frequently found in bladder cancer, increases their resistance to ionizing radiation. Other studies, however, suggest that mutations of the p53 gene could increase the radiosensitivity of cancer cells, although the evidence is still inconclusive. In the present study, we investigated the relationship between p53 status and radiation response in five different bladder cancer cell lines. Materials and Methods. Five different human bladder cancer cell lines (KK47: with wt-p53, RT4: with wt-p53, T24: with mutated p53, 5637: with mutated p53, UM-UC-3: with mutated p53) were used in the study. Cells were irradiated with 0, 2, 4, 6 or 8 Gy, then trypsinized and re-plated for clonogenic survival assay, quantitative RT-PCR assay, flow-cytometry analysis and TUNEL assay. Results. The clonogenic assay demonstrated that KK47 and RT4 had significantly higher radiosensitivity than other cell lines. Quantitative RT-PCR analysis showed that radiation induced increased expression of p53, Bax, and p21 mRNA in KK47 and RT4. After irradiation, G1 cell-cycle arrest was observed in KK47 and RT4 under flow cytometry analysis, while T24, 5637, and UM-UC-3 showed an increase in the proportion of G2 cells. Increased cell apoptosis was also observed under TUNEL assay in KK47 and RT4, but not in other cell lines. Conclusions: It was demonstrated that ionizing radiation induces p53-dependent cell apoptosis in bladder cancer cells with wt-p53 but not in those with mutated p53.     

Gene therapy for bladder cancer

Tumor-suppressor genes can be transferred into tumor cells in vivo using a replication-defective adenoviral vector. P53 mutations are frequent in bladder cancer, and adenovirus-mediated p53 gene transfer is growth-inhibitory to bladder cancer cells in vitro. The vector Ad5CMV-P53, which contains human wild-type p53, is being administered intravesically to patients with bladder cancer in a phase I clinical trial. The results of this study will provide the basis for phase II and phase III trials in which gene therapy will be integrated with existing therapies for improved local control and opportunities for bladder preservation.     

Effects of clotrimazole on the growth, morphological characteristics, and cisplatin sensitivity of human glioblastoma cells in vitro

OBJECT: Clotrimazole, an antimycotic drug, inhibits proliferation of normal and cancer cells by downregulating the movement of intracellular Ca++ and K+. The authors examined the effect of clotrimazole on the growth and sensitivity to cisplatin of two human glioblastoma cell lines--A172, which has the wild-type p53 gene, and T98G, which has the mutant p53 gene in vitro. METHODS: The A172 and T98G glioblastoma cells were exposed to clotrimazole and cell growth was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium chloride colorimetric assay. Clotrimazole produced a dose-dependent inhibition of cell proliferation and caused changes in cellular structure toward a well-differentiated form. The growth inhibitory effect of clotrimazole was reversible. Western immunoblot analysis revealed a marked increase in cellular glial fibrillary acidic protein and wild-type p53 and a decrease in c-myc and c-fos oncoproteins in both cell lines treated with clotrimazole. Flow cytometric analysis revealed that clotrimazole-treated cells accumulated in the G0/G1 phase with a marked decrease in cells in the S phase; when clotrimazole was washed out from the culture medium, cells again started to proliferate, with a marked decrease in cells in the G0/G1 phase and an increase in cells in the S phase. The growth inhibitory effect of clotrimazole could not be overcome by exogenous stimulation with either epidermal growth factor or c-myc peptide. A combined treatment with clotrimazole and cisplatin significantly enhanced cell cytotoxicity compared with treatment using either drug alone. A DNA fragmentation assay showed that both clotrimazole and cisplatin induced apoptosis, which was increased in cells treated by both drugs. CONCLUSIONS: The present study indicates that clotrimazole inhibits cell proliferation accompanied by morphological changes toward differentiation of glioblastoma cells and that this drug synergistically enhances the antitumor effect of cisplatin by inducing wild-type p53-mediated apoptosis.     

p53重组腺病毒联合顺铂或三氧化二砷对人膀胱癌EJ细胞的作用

目的：探讨p53重组腺病毒（Ad-p53）与顺铂（CDDP）或三氧化二砷（As2O3）联合应用提高膀胱癌疗效的可能性及其机制。方法：将Ad-p53[100感染强度（MOI）]与CDDP（0．5mg/L)或As2O3(2.0μmol/L）联合应用，通过细胞生长抑制实验、克隆形成实验、细胞周期分析、免疫组织化学分析以及裸鼠皮下移植瘤模型，观察其对膀胱癌EJ细胞的作用及机制。结果：与单独应用相比，Ad-p53与低剂量的CDDP或As2O3联合可明显抑制EJ细胞体外生长，诱导EJ细胞凋亡，EJ细胞G2／M期阻滞更明显；裸鼠体内肿瘤发生时间延迟，4周后肿瘤体积与单独应用时相比，差异有显著性（P＜0．05）。结论：基因治疗与化疗联合应用，可进一步提高膀胱癌的疗效。     

E-cadherin和CAR在人膀胱癌细胞中的表达及其意义

目的检测上皮型钙黏素（E—cadherin）和柯萨奇-腺病毒受体（coxsackie and adenovirus receptor，CAR）在多种人膀胱癌细胞中的表达情况，初步讨论E-cadherin与CAR在人膀胱癌细胞中表达的意义及两者间的关联。方法用Western印迹法测定人膀胱癌细胞中E—cadherin和CAR的表达情况。结果E—cadherin，CAR在RT4、5637细胞中表达较高，在253J细胞中表达较低；E—cadherin在J82、T24细胞中不表达，CAR在J82细胞中微弱表达，在T24中不表达。结论E-cadherin和CAR在人膀胱癌细胞中的表达趋势一致，两者可能相互协作，共同参与膀胱癌的侵袭转移过程。     

P53 mutation correlates with cisplatin sensitivity in head and neck squamous cell carcinoma lines

BACKGROUND: A critical factor for successful organ preservation treatment in head and neck cancer may be selecting tumors that respond to chemotherapy and radiation. Previous results in patients indicated that tumors that overexpressed p53 were more sensitive to chemotherapy than those that did not overexpress p53. METHODS: To determine the relationship of p53 mutations to sensitivity to cisplatin in vitro, 23 head and neck squamous cell carcinoma (HNSCC) cell lines were analyzed for cisplatin sensitivity, p53 expression, and p53 mutation status. RESULTS: Mutations of the p53 gene were identified in 13 of 23 of the cell lines tested. Mutation of the p53 gene was significantly associated with high levels of expression of the p53 protein. The average ID(50) (drug dose required to inhibit 50% of cell growth) for cell lines with mutant p53 was 6.8 microM, whereas the average ID(50) for cell lines with wild-type p53 was 13.7 microM. CONCLUSIONS: These in vitro data support a role for mutation of the p53 tumor suppressor gene as a marker for response to cisplatin in HNSCC.