Improving adenoviral vectors and strategies for prostate cancer gene therapy

Gene therapy has been evaluated for the treatment of prostate cancer and includes the application of adenoviral vectors encoding a suicide gene or oncolytic adenoviruses that may be armed with a functional transgene. In parallel, versions of adenoviral vector expressing the p53 gene (Ad-p53) have been tested as treatments for head and neck squamous cell carcinoma and non-small cell lung cancer. Although Ad-p53 gene therapy has yielded some interesting results when applied to prostate cancer, it has not been widely explored, perhaps due to current limitations of the approach. To achieve better functionality, improvements in the gene transfer system and the therapeutic regimen may be required. We have developed adenoviral vectors whose transgene expression is controlled by a p53-responsive promoter, which creates a positive feedback mechanism when used to drive the expression of p53. Together with improvements that permit efficient transduction, this new approach was more effective than the use of traditional versions of Ad-p53 in killing prostate cancer cell lines and inhibiting tumor progression. Even so, gene therapy is not expected to replace traditional chemotherapy but should complement the standard of care. In fact, chemotherapy has been shown to assist in viral transduction and transgene expression. The cooperation between gene therapy and chemotherapy is expected to effectively kill tumor cells while permitting the use of reduced chemotherapy drug concentrations and, thus, lowering side effects. Therefore, the combination of gene therapy and chemotherapy may prove essential for the success of both approaches.

Efecto mutagénico y genotóxico, y expresión de los genes Rad51C , Xiap , P53 y Nrf2 inducidos por extractos antipalúdicos de plantas recolectadas en el Vaupés medio, Colombia / Mutagenicity, genotoxicity and gene expression of Rad51C, Xiap, P53 and Nrf2 induced by antimalarial extracts of plants collected from the middle Vaupés region, Colombia

Resumen Introducción. Dada la resistencia de Plasmodium a los medicamentos antipalúdicos, es necesario encontrar nuevas alternativas terapéuticas para su tratamiento y control. Con base en el saber indígena colombiano, se recopilaron extractos de plantas del Vaupés medio con potencial efecto antipalúdico. Objetivo. Evaluar el efecto mutagénico y genotóxico, y la expresión de los genes Rad51C, Xiap, P53 yNrf2, inducidos por cuatro extractos etanólicos con actividad anti-Plasmodium(R001, T002, T015 y T028). Materiales y métodos. Se evaluó el potencial mutagénico de cuatro extractos etanólicos con efecto antiplasmódico utilizando el test de Ames y el efecto genotóxico, con un ensayo del cometa; asimismo, se analizó la expresión de los genes Rad51C, Xiap, P53 y Nrf2 en células HepG2. Resultados. Los extractos no fueron mutágenos en la cepa TA98 de Salmonella typhimurium en presencia y ausencia de actividad metabólica de la fracción S9. En la cepa TA100, los extractos R001, T015 y T028 se comportaron como mutágenos débiles en presencia de S9, con índices mutagénicos de 1,58; 1,38; 1,53 y 1,61, respectivamente; T015 tuvo el mismo comportamiento en ausencia de S9, con un índice mutagénico de 1,36. En el ensayo del cometa, todos los extractos provocaron daño de categorías 1 o 2, con colas de cometas entre 36,7 y 51,48 µm de longitud; sin embargo, el índice dedaño genético sugirió que los tratamientos afectaron la mayoría de las células. En los genes en estudio, los extractos R001 y T028 indujeron una sobreexpresiónde 1,84 a 3,99 frente a las células sin tratar de los genes Xiap y P53. Conclusiones. Los resultados evidenciaron que el extracto T002 fue el más seguro, ya que presentó actividad anti-Plasmodium, no fue citotóxico en las células HepG2, no fue mutágeno, causó daño de categoría 1 en el ADN y no modificó la expresión de los genes evaluados.

Abstracts Introduction: Due to Plasmodium resistance to antimalarial drugs, it is important to find new therapeutic alternatives for malaria treatment and control. Based on the knowledge of Colombian indigenous communities, we collected extracts of plants with potential antimalarial effects from the middle Vaupés region. Objective: To evaluate the mutagenic and genotoxic effects, as well as the gene expression of Rad51C, Xiap, P53 and Nrf2 induced by four ethanolic extracts with antimalarial activity (R001, T002, T015 and T028). Materials and methods: We evaluated four ethanolic extracts with antimalarial activity using the Ames test to assess mutagenicity, and the comet assay on HepG2 cells to determine the genotoxicicity. We also evaluated the expression of Rad51C, Xiap, P53 and Nrf2 from HepG2 cells stimulated with the four extracts. Results: None of the four extracts was mutagenic in Salmonella typhimurium TA98 strain in the presence and absence of S9 metabolic activity. Extracts R001, T015 and T028 were weakly mutagenic on the TA100 strain in the presence of S9, with mutagenic indexes (MI) of 1.58, 1.53 and 1.61, respectively. The T015 strain showed the same behavior without S9 with an MI of 1.36. The results of the comet assay showed that the four extracts produced category 1 or 2 damage, with comets between 36.7 and 51.48 µm in length. However, the genetic damage index suggested that most of the cells were affected by the treatments. Regarding gene expression, extracts R001 and T028 induced an overexpression of genes Xiap and P53 with an 1.84 to 3.99 fold-change compared with untreated cells. Conclusions: These results revealed that the T002 extract was the safest as it had antimalarial activity and was not cytotoxic on HepG2 cells. Moreover, it was not mutagenic and it only produced category 1 damage on the DNA. Also, the extract did not induce a change in the expression of the tested genes.

Immunohistochemical detection of p53 and MDM2 expressions in liposarcoma with World health organization classification.

BACKGROUND: Liposarcomas are among the most common soft tissue sarcomas in adulthood. AIM: The purpose of the study is to perform a histopathologic typing according to World Health Organization (WHO) classification of cases diagnosed with liposarcoma and to examine the difference of p53 and MDM2 expressions. MATERIALS AND METHODS: The haematoxylin-eosin stained sections of 48 subjects enrolled in the study have been evaluated on the basis of the WHO classification for liposarcoma and sections stained using p53 and MDM2. STATISTICAL ANALYSIS USED: Chi-Square test was applied. RESULTS: 20 subjects were diagnosed with well-differentiated liposarcoma (WLS), 16 myxoid liposarcoma (ML), 7 pleomorphic liposarcoma (PL), and 5 de-differentiated liposarcoma (DLS). The number of cases stained positive with MDM2 and p53 were positive correlated in all subjects (P = 0.02). p53 and MDM2 positivity increased in high grade tumors (P = 0.01). CONCLUSION: p53 and MDM2 immuno-reactivity was found to be potentially useful in liposarcoma diagnosis but a definitive implication would be rather unhealthy due to the small number of cases in our study.

Expression of JMJD2A in infiltrating duct carcinoma was markedly higher than fibroadenoma, and associated with expression of ARHI, p53 and ER in infiltrating duct carcinoma.

Jumonji Domain Containing 2A (JMJD2A) may be a cancer-associated gene involved in human breast cancer. With a view to investigating expression of JMJD2A in human breast cancer and benign lesion tissues as well as relationship between JMJD2A and tumor related proteins, histological and immunohistochemical analysis, Western blot and quantitative real-time PCR in infiltrating duct carcinoma and fibroadenoma for JMJD2A and immunohistochemical analysis and quantitative real-time PCR in infiltrating duct carcinoma for tumor related proteins (ARHI, p53, ER, PR and CerbB-2) were performed. Histological examination validated the clinical diagnosis. The JMJD2A positive rate of infiltrating duct carcinoma was significantly higher than fibroadenoma by immunohistochemical analysis. The mean optical density of JMJD2A in infiltrating duct carcinoma was higher than fibroadenoma by western blot. JMJD2A mRNA level in infiltrating duct carcinoma was higher than fibroadenoma by quantitative real-time PCR. Spearman correlation analysis revealed that the expression of JMJD2A was associated with ARHI, p53 and ER from immunohistochemical results respectively. Pearson correlation analysis revealed that the expression of JMJD2A was associated with ARHI, p53 and ER from quantitative real-time PCR results respectively. Expression of JMJD2A in infiltrating duct carcinoma was higher, and associated with ARHI, p53 and ER. The results may take JMJD2A as a potential diagnostic and therapeutic target in human breast cancer.

Correlations in survivin expression with the expression of p53 and bcl-2 in invasive ductal carcinoma of the breast.

This work studied the correlations between survivin, bcl-2 and p53 in infiltrating ductal carcinoma of the breast. A total number of 382 cases were collected from 3 hospitals in northeastern Malaysia. Survivin, bcl-2 and p53 were detected by immunohistochemistry on samples prepared from tissue blocks. Significant correlations were found between tumor histological grades and tumor size and lymph node involvement. Highly significant statistical correlations (p<0.001) were found in expression of the markers under study. It is concluded that such significant correlations may imply that the alterations in the expression take place in a concerted fashion, implying that many of these cases may share common abnormalities.

Histological spectrum of ependymomas and correlation of p53 and Ki-67 expression with ependymoma grade and subtype.

BACKGROUND: Clinical and histological criteria for ependymoma prognosis are well recognized. Recently few studies have been done based on Immunohistochemistry for prognostication of these tumours. In this study we have correlated the histological spectrum with immmunoexpression of p53 and Ki67 in these tumors. AIMS: To know the incidence of ependymomas; study their morphological spectrum and to evaluate expression of P53 and Ki 67 in different morphological subtypes. MATERIAL AND METHOD: A retrospective study was preformed on 70 ependymomas received in a period between 1994 and 2001. Entire tissue received was processed for routine paraffin embedded H&E stained sections. Immunocytochemistry was performed using antibodies to GFAP, EMA, Pancytokeratin and synaptophysin, to differentiate papillary ependymoma from choroid plexus papilloma; clear cell ependymoma from oligodendroglioma and central neurocytoma; ependymoblastoma from other embryonal tumours. p53 and Ki-67 immunohistochemistry was performed to correlate their expression with various tumour grades and subtypes. RESULTS: There were 3 cases (4.2%) of Grade I ependymoma (2 cases of myxopapillary ependymoma and 1 case of subependymoma); 57 cases (81.5%) of ependymoma grade II (43 of these were of classical variety, 11 of clear cell ependymoma, 2 of papillary and 1 case of cellular ependymoma). There were 9 cases (12.8%) of anaplastic ependymoma (one of these was a clear cell ependymoma and 1 case (1.5%) of ependymoblastoma CONCLUSION: p53 and Ki67 indices can be used in routine diagnostic laboratories to supplement the tumor grade on histology and more studies with follow up should be performed to analyse the prognosis of different subtypes. The expression of Ki 67 and p53 was significantly higher in anaplastic ependymomas. 4 out of 11 cases of clear cell ependymomas showed higher Ki 67 indices as compared to classical grade II ependymomas, thus further highlighting the importance of differentiating the various subtypes.

Mutation and overexpression of p53 as a prognostic factor in canine mammary tumors

We concentrated ourselves to evaluate the prognostic significance of the p53 gene mutations, its protein expression and MIB-1 index as a proliferative marker in canine mammary tumors. In the present study, a total of 20 cases were examined, among which there were 5 malignant mixed tumors, 4 mammary gland adenocarcinomas, 1 papillary adenocarcinoma, 8 benign mixed tumors and 2 mammary gland adenomas. Positive immunostaining for p53 with PAb240 antibody was found in 2 benign (20%) and 3 malignant (30%) tumors. However, PAb421 antibody did not give positive result at all. In Western blot analysis, the p53 expression in benign and malignant tumors was detected in 4 and 3 cases, respectively. p53 mutations were found in 6 cases out of the cases with detected p53 protein expression. The MIB-1 index in benign and malignant tumors were 17.6+/-20.8% and 29.0+/-27.2%, respectively and there was no significant difference between tumor types. There was a significant correlation between p53 mutations and p53 overexpression (correlation coefficient = 0.5, p < 0.05). In Kaplan-Meier survival analysis, the p53 index was associated with significantly shortened survival time (p < 0.01). In multivariate analysis, p53 overexpression was only an independent factor for indicator of worse prognosis in canine mammary tumors (p = 0.01). These results demonstrated that p53 gene mutations and protein overexpression using the PAb240 anti-p53 antibody were useful predictors of increased malignant potential and poor prognosis in canine mammary tumors.

p53 aberrations in oral sub mucous fibrosis and oral cancer detected by immunohistochemistry.

Study of expression of p53 oncoprotein in several precancerous and cancer have been done, but only one literature is available regarding p53 expression in Oral Sub Mucous Fibrosis (OMSF), hence this study was taken up (i) to determine the expression of aberrant p53 in Oral Sub Mucous Fibrosis (OSMF) and Oral Squamous cell carcinoma (SCC) patients. (ii)To study correlation if any between p53 expression and degree of dysplasia in OSMF and SCC patients and (iii)To study correlation if any between p53 expression and habits in OSMF and SCC patients. Study Design consists of biopsy specimens of 38 cases of OSMF and 37 cases of Squamous cell carcinoma were subjected for staining by immunohistochemistry for p53 protein using LSAB visualization system kit. Clinical details along with habits were recorded and the data analyzed with t- test and chi- square test. Results of the study reveals 18 cases of OSMF and 26 cases of SCC were positive for p53 protein. Only 4 cases of SCC showed (++)grade and the rest all had (+)grade. Out of 75 patients, 65 had the habit of smoking and chewing, 4 patients history of habit was not known. Among patients with habits (65), 40 specimens were +ve for p53 stain and 2 out of 6 without history of habit, 2 out of 4 unknown history of habit took up p53 stain. To conclude study showed higher percentage of p53 positive cells in oral cancer cases when compared to oral sub mucous fibrosis cases. It suggests p53 expression may correlate with increase in dysplasia or malignant transformation. Both smoking and chewing habits had a significant role in p53 positive expression.

Thyroid Transcription Factor-1 (TTF-1) Expression in Human Lung Carcinomas: Its Prognostic Implication and Relationship with Expressions of p53 and Ki-67 Proteins

This study was aimed to evaluate the prevalence and prognostic implication of thyroid transcription factor-1 (TTF-1) immunoreactivity in 81 human lung carcinomas, including 65 cases of non-small cell lung carcinoma (NSCLC) and 16 cases of small cell lung carcinoma (SCLC); and also to investigate its relationship with the cell proliferation and regulation by immunostaining of Ki-67 and p53 proteins, respectively. The immunohistochemical staining for TTF-1(clone 8G7G3/1) was performed and several clinicopathologic variables and the follow-up data were obtained. The immuno-staining results for TTF-1 were semiquantitatively interpreted as negative and positive. Of NSCLCs, TTF-1 is highly expressed in adenocarcinomas (76%), whereas squamous cell carcinomas revealed no immunoreactivity (0%). SCLCs showed strong TTF-1 expression (88%). In NSCLC, TTF-1 expression was inversely correlated with Ki-67 proliferative activity and independent of p53 overexpression. TTF-1(+) group tended to show better survival than TTF-1(-) group in NSCLC. Conclusively, these observations suggest that TTF-1 is a sensitive and specific diagnostic marker for pulmonary adenocarcinomas and SCLCs; that TTF-1 might have a good prognostic implication based on its inverse correlation with Ki-67 proliferative activity and tendency for better survival in NSCLC; that this cell lineage marker may play a role in the molecular pathogenesis of lung cancers at the level of transcription.

Primary Intraosseous Malignant Fibrous Histiocytoma of the Skull: A Case Report

Malignant fibrous histiocytoma(MFH) is a rare primary neoplasm that constitutes less than 1% of the malignant tumors of bone, and involvement of the skull is very rare. We present a case of malignant fibrous histiocytoma of the skull, presenting an intraosseous lesion in a 43-yr-old woman. She had a rapidly growing, tender mass in the right parietal region. A plain radiograph showed an osteolytic lesion of the right parietal bone. Magnetic resonance imaging revealed that the lesion showed heterogeneous low signal intensity on T1-weighted images and slightly high signal intensity on T2-weighted images. No evidence of an extraosseous extension to the adjacent dura and soft tissue was found, and a wide excision of the parietal bone was performed. Histologically, the tumor was a typical MFH displaying pleomorphic spindle cells in a storiform pattern. The results of immunohistochemical stainings revealed that the tumor cells were positive for vimentin, alpha-1-antitryp-sin, and p53, and negative for smooth muscle actin, S100 protein, desmin, and MyoD1. Three months later, a mainly cystic, recurrent mass was developed at the previously operated site. Before the resection, we first performed the percutaneous aspiration cytology, revealing diagnostic multinucleated pleomorphic cells. There-after, she had to receive repetitive resections of recurrent or residual lesions, and she died of postoperative meningoencephalitis two years after the first operation.

Expression of Cyclin B1 and cdc2 in Nodal Non-Hodgkin's Lymphoma and its Prognostic Implications

To investigate the role of cyclin B1 and cdc2 in the pathogenesis and progression of malignant lymphoma, 68 cases of nodal non-Hodgkin's lymphoma were examined about the expression of cyclin B1 and cdc2 along with p53 and Ki-67 by immunohistochemical method. The correlation of their expression with various clinicopathologic findings was also analyzed. Cyclin B1 and cdc2 were diffusely expressed in 39 cases (57.4%) and 54 cases (79.4%) out of 68 cases studied, respectively. The mean labeling indices of cyclin B1 and cdc2 in malignant lymphoma were 31.9% and 68.0%, respectively. In normal lymphoid tissues, cyclin B1 and cdc2 were expressed predominantly in the germinal center with mean labeling indices of 13.9% and 28.3%, respectively. The correlation between the expression of cyclin B1 and cdc2 was noted (p=0.013). The expression of Ki-67 was correlated with that of cyclin B1 (p=0.023) and marginally correlated with that of cdc2 (p=0.056). The expression of cdc2 and p53 in complete remission group to chemotherapy was lower than that of progressive disease group (p=0.047, p=0.049). In multivariate analysis, the clinical stage alone showed significance on overall survival (p=0.049). In conclusion, cyclin B1 and cdc2 appeared to be involved in the genesis or progression of malignant lymphoma and cdc2 can be a useful marker for response to chemotherapy.

Clinical Prognostic Values of Vascular Endothelial Growth Factor, Microvessel Density,and p53 Expression in Esophageal Carcinomas

Vascular endothelial growth factor (VEGF) is known to play a key role in tumor angiogenesis. The tumor-suppressor gene p53 has been thought to regulate VEGF. We investigated the effect of VEGF on esophageal carcinoma and the correlation between VEGF and p53. Tissue samples were taken from 81 patients with esophageal carcinoma after surgery. VEGF and p53 expressions were examined by immunohistochemical staining. Microvessels in the tumor stained for CD34 antigen were also counted. VEGF and p53 expressions were observed in 51.3% (41/80) and 51.9% (41/79), respectively. The microvessel density was 70.9+/-6.7 (mean+/-SE) in VEGF-positive group and 68.7+/-5.1 in VEGF-negative group. However, no correlation was noted between VEGF and p53 expression. Whereas the tumor size, nodal status, depth of invasions, and tumor stage were associated with poor overall survival, VEGF expression or p53 expression was not. These results indicate that VEGF and p53 are highly expressed in esophageal carcinomas. Since the VEGF expression is not correlated with the p53 expression, microvessel density or clinicopathological findings, further studies with other angiogenic molecules are needed to determine the role in esophageal carcinomas.

Coexpression of MUC1 with p53 or MUC2 correlates with Lymph Node Metastasis in Colorectal Carcinomas

The alteration of the mucin profile have been known to play a role in colorectal carcinogenesis. MUC1 is up-regulated and MUC2 is down-regulated in colorectalcarcinomas. Overexpression of p53 is frequently noted in colorectal carcinomas with deep invasion or lymph node metastasis. However, there have been few reports about the association between MUC1, MUC2, and p53 expression with respect to the metastatic potential. This study was aimed to investigate the relationship of MUC1, MUC2, and protein p53 expressions with clinicopathological factors in colorectal carcinomas. Expressions of MUC1, MUC2, and p53 protein were examined immunohistochemically. Of total 97 cancers, 44 (45%) were MUC1 positive, 39 (40%) were MUC2 positive and 58 (59%) showed a p53 overexpression. Coexpression of MUC1 with p53 and dual expression of MUC1 with MUC2 were associated with a higher frequency of lymph node metastasis (p<0.05). The right colon showed a higher MUC1 positivity and frequent lymph node metastasis than the left colon (p<0.05). These results suggest that the coexpression of MUC 1 with p53 or MUC2 are involved in regional lymph node metastasis in colorectal carcinomas. The high expression of MUC1 in the right colon cancer was revealed to relate with lymph node metastasis.

Correlation of Mutation and Immunohistochemistry of p53 in Hepatocellular Carcinomas in Korean People

The degree of correlation between sequencing and immunohistochemisty (IHC) for detecting mutations of p53 has not been well established in human hepatocellular carcinoma (HCC). We analyzed 36 HCCs from Korean people for p53 mutation at exons 4-10 by PCR-SSCP and sequencing, and compared the results with the IHC positivity. p53 mutations were identified in 7 out of 36 HCCs (19.4%). These mutations were found widely throughout exons 4-8. No mutation was detected in codon 249. Among the 7 mutations, 6 missense mutations were detected in 15 HCCs with >or=5% immunoreactive tumor cells and one nonsense mutation was in 21 HCCs with or=5% overexpression group than in >or=10% overexpression group or >0% overexpression group. This study suggests that 5% immunoreactivity is a reliable immunohistochemical threshold value to detect p53 mutations in HCCs and the spectrum of p53 mutations in HCCs in Korean people is different from that of high aflatoxin B1 exposure areas.

The Role of Vascular Endothelial Growth Factor (VEGF) and p53 Status for Angiogenesis in Gastric Cancer

BACKGROUND: Angiogenesis is of crucial importance for tumor growth and development of metastases. Vascular endothelial growth factor (VEGF) has a potent angiogenic activity and mutations of the p53 gene has been thought to upregulate VEGF. The purpose of our study was to evaluate the prognostic significance of these tumor biomarkers for angiogenesis relative to the information derived from established clinicopathological parameters in gastric cancer. METHODS: In this study, we conducted an immunohistochemical investigation of VEGF and p53 expression in 145 tissue samples obtained from gastric cancer patients undergoing curative surgical treatment. To evaluate angiogenesis, microvessel density (MVD) was counted by staining endothelial cells immunohistochemically using anti-CD34 monoclonal antibody. RESULTS: High MVD was significantly associated with depth of tumor invasion and distant metastasis (p=0.004, 0.021, respectively). Moreover, overall survival for patients with high MVD were significantly lower than that of low MVD (p=0.048). Positive expression of VEGF correlated significantly with lymph node and distant metastasis (p=0.040, 0.048, respectively). However, no significant correlation was found between p53 expression and various clinicopathological parameters. VEGF positive tumors showed a higher MVD than VEGF negative tumors (p=0.028). The expression of p53 did not correlate with VEGF expression. Also, the relationship between the status of p53 expression and MVD had not statistically significant differences. In the multivariate analysis, status of VEGF, p53 expression and MVD were not an independent prognostic factor. CONCLUSION: VEGF seems to be an important, clinically relevant inducer of angiogenesis and angiogenesis assessed by the MVD may be a useful marker for predicting metastasis in gastric cancer. However, further studies are warranted to clarify the impact of p53 on the angiogenesis and the prognostic significance of angiogenesis in gastric cancer.

Expression of c-erbB-2, p53 and c-myc proteins in male breast carcinoma: Comparison with traditional prognostic factors and survival

There are few data evaluating biological markers for men with breast cancer. The purpose of the present study was to analyze the expression of the oncogenes c-erbB-2 and c-myc and of the suppressor gene p53 by immunohistochemical techniques in archival paraffin-embedded tissue blocks of 48 male breast cancer patients, treated at the A.C. Camargo Cancer Hospital, Säo Paulo, SP, Brazil. The results were compared with clinicopathological prognostic features. Immunopositivity of c-erbB-2, p53 and c-myc was detected in 62.5, 16.7 and 20.8 percent of the cases analyzed, respectively. Estrogen and progesterone receptors were positive in 75 and 69 percent of the cases, respectively. Increasing staging was statistically associated with c-erbB-2 (P = 0.04) and weakly related to p53 positivity (P = 0.06). No significant correlation between specific survival rate (determined by the log rank test) and the molecular markers analyzed was found, whereas the number of compromised lymph nodes and advanced TNM (tumor, node, metastasis) staging were associated with diminished survival

p53 protein expression and its prognostic importance in patients with nodal non-Hodgkin's lymphoma

To determine whether the p53 expression might be a predictor for treatment sponse and overall survival in nodal non-Hodgkin's lymphoma (NHL), we analyzed e expression of p53 in 69 NHL patients. p53 protein expression was analyzed by munohistochemistry with long-term follow up (1-148 months: median 12.2). p53 pression was noted in 23/69 (33.3%) patients. Complete response (CR) rate to stemic chemotherapy was correlated with stage (I/II) (p=0.038), but not with 3 expression (p=0.2856). Poor overall survival was associated with stage =0.0010) or IPI score (p=0.0076), but not with p53 expression (p=0.8601). From ratification analysis by stage, in stage III/IV patients, the p53 positive oup had a trend to be associated with poor overall survival than the p53 gative group. Multivariate analysis revealed that p53 positive group was sociated with less CR rate compared to the p53 negative group (p=0.046), ereas overall survival was correlated with stage (p=0.0320), not with p53 atus. p53 expression was associated with less CR rate in patients with DLBL. rther studies with large numbers of samples and homogenous group of NHL are eded to determine the prognostic value of cell cycle regulator, p53 in NHL.

Detecting p53 gene mutation of breast cancer and defining differences between silver staining PCR-SSCP and immunohistochemical staining

This study detects and defines the patterns of p53 gene mutations in breast cancers. We analyse p53 gene mutations through comparing the results of single-strand-conformation-polymorphism (SSCP) and immunohistochemistry (IHC), and we try to define the differences between the results of SSCP and IHC. Twenty-seven fresh primary breast cancer tissues and eight normal breast tissues were studied. The IHC was done with the usual streptavidin-biotin peroxidase complement method by using monoclonal antibody DO-7. The results of staining was scored. The SSCP method was done by using Cold SSCP Electrophoresis System. Overexpressions of p53 protein were seven (25.9%) among 27 cancer cases on IHC. Four (57.1%) of seven cases were positive in SSCP. In SSCP, the mutations were detected in 10 (37%) among 27 cancer cases. The mutations were two in exon 5, one in exon 8, and seven cases in exon 7. All of 10 mutations were proved by sequencing analysis. Of them, only four (40%) were positive in IHC. We consider the IHC as a screening method for p53 gene mutations.

Effects of allyl sulfur compounds and garlic extract on the expression of Bcl-2, Bax, and p53 in non small cell lung cancer cell lines

Allyl sulfur compounds play a major role in the chemoprevention against carcinogenesis. The present study compared the antiproliferative effects of diallyl sulfide (DAS), diallyl disulfide (DADS) and garlic extract on p53-wild type H460 and p53-null type H1299 non small cell lung cancer cells (NSCLC). The DAS and DADS treatment of both H460 and H1299 cells resulted in the highest numbers of cells in apoptotic state as measured by acridine orange staining, however, garlic extract treatment did not induce any significant apoptotic cells by MTT assay. DADS was found to be more effective in inducing apoptosis on NSCLC. The level of p53 protein in H460 cell was increased following DADS treatment. DAS and garlic extract treatment of H460 cells induced a rise in the level of Bax and a fall of Bcl-2 level. These results demonstrate that DAS, DADS and garlic extract are effective in reduction of anti-proliferative gene in NSCLC and suggest that modulation of apoptosis-associated cellular proteins by DAS, DADS and garlic extract may be the mechanism for apoptosis which merit further investigation as potential chemoprevention agents.

Topographic expression of p21WAF1/SDI1/CIP1, bcl2, and p53 is altered at the early stage of colorectal carcinogenesis

We analyzed the expression of p21, bcl2, and p53 in normal and different pathologic mucosa of the human colorectum using immunohistochemistry and cold polymerase chain reaction-single strand conformation polymorphism. The topography of normal mucosa showed; bcl2 and p53 expression restricted to basal epithelial cells and p21 expressed only in superficial epithelial cells. This topographic expression was altered in hyperplastic polyps and adenomas. Hyperplastic polyps revealed absence of or weak bcl2 expression and strong p21 expression without topography. In adenomas, whereas bcl2 expression increased and extended to parabasal and superficial dysplastic epithelium, the increase of p21 expression was limited to surface dysplastic epithelium. p53 was weakly expressed throughout the full thickness of dysplastic epithelium. Bcl2 expression in adenomas was stronger than in carcinomas; p53 expression was converse and p21 expression was variable. In carcinomas, this topographic expression was largely abrogated but p53 mutation (36%) was more frequent than in adenomas (2%). In carcinomas, p21 and p53 expression correlated inversely, but there was no relationship with bcl2. These results suggest that there is precisely ordered topographic pattern of p21, bcl2, and wild p53 expression in normal colorectal cells, but this becomes disordered during the early stage of colorectal carcinogenesis.