References of "Hachana, Mohamed Ridha"
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See detailClinicopathologic significance of DNA methyltransferase 1, 3a, and 3b overexpression in Tunisian breast cancers.
Ben Gacem, Riadh; Hachana, Mohamed Ridha ULg; Ziadi, Sonia et al

in Human Pathology (2012)

DNA methyltransferase 1, 3a, and 3b affect DNA methylation, and it is thought that they play an important role in the malignant transformation of various cancers. The current study was designed to analyze ... [more ▼]

DNA methyltransferase 1, 3a, and 3b affect DNA methylation, and it is thought that they play an important role in the malignant transformation of various cancers. The current study was designed to analyze DNA methyltransferase expression by immunohistochemistry in a series of 94 Tunisian sporadic breast carcinomas. Results were correlated to clinicopathologic parameters and promoter methylation status of 8 tumor suppressor genes (BRCA1, BRCA2, RASSFA1, TIMP3, CDH1, P16, RARβ2, and DAPK). Overexpression of DNA methyltransferase 1, 3a, and 3b was detected in 46.8%, 32%, and 44.7% of cases, respectively. A significant correlation was found between DNA methyltransferase 1 overexpression and Scarff-Bloom-Richardson histologic grade III (P = .01). DNA methyltransferase 3a overexpression was significantly associated with menopausal status (P = .01), Scarff-Bloom-Richardson histologic grade III (P = .0001), estrogen (P = .04) and progesterone (P = .007) receptor negativity, and HER2 overexpression (P = .004). However, DNA methyltransferase 3a overexpression was found less frequently in the luminal A intrinsic breast cancer subtype (9.7%) than in luminal B (53%), HER2 (41%), and triple-negative (50%) subtypes (P = .001). DNA methyltransferase 3b overexpression shows significant correlation with promoter hypermethylation of BRCA1 (P = .03) and RASSFA1 (P = .04) and with the hypermethylator phenotype (more than 4 methylated genes, P = .01). These data suggest that overexpression of various DNA methyltransferases might represent a critical event responsible for the epigenetic inactivation of multiple tumor suppressor genes, leading to the development of aggressive forms of sporadic breast cancer. [less ▲]

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See detailContribution of epigenetic alteration of BRCA1 and BRCA2 genes in breast carcinomas in Tunisian patients
Ben Gacem, Riadh; Hachana, Mohamed Ridha ULg; Ziadi, Sonia et al

in Cancer Epidemiology, Biomarkers & Prevention : A Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology (2011)

Objective: The aim of this study was to evaluate the contribution of the BRCA1 and BRCA2 promoter methylation in the pathogenesis of sporadic breast cancer in Tunisian patients. Methods: Breast carcinoma ... [more ▼]

Objective: The aim of this study was to evaluate the contribution of the BRCA1 and BRCA2 promoter methylation in the pathogenesis of sporadic breast cancer in Tunisian patients. Methods: Breast carcinoma tissues (n=117) and available paired normal breast tissues (n=65) from Tunisian women who had no family history were investigated for the methylation status of BRCA1 and BRCA2 promoters using methylation-specific PCR. Breast specimens from women without carcinoma (16 fibroadenomas and 5 mastopathies) were used as control. Results: Hypermethylation of BRCA1 and BRCA2 promoters was detected respectively in 60.7% and 69.2% of the carcinoma tissues, and in only 7.7% and 4.6% of the paired normal breast tissues. None of the fibroadenomas and mastopathies showed hypermethylation. Correlations were found between BRCA1 and BRCA2 hypermethylation and decrease in their mRNA expression (p=0.02 and p=0.009, respectively). Moreover, BRCA1 methylation correlates with patients age (p=0.01) and triple negative (ER-, PR-, HER2-) tumors (p=0.01). Patients with methylated BRCA1 and/or BRCA2 had a significant prolonged survivals compared to those with unmethylated tumors (p=0.002). Conclusion: Our results suggest an important role of BRCA1 and BRCA2 promoter methylation in breast cancer development in the Tunisian population. [less ▲]

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See detailUtilité de l'immuno-histochimie dans la détection des altérations des gènes réparateurs des mésappariements de l'ADN À propos d'une série de 48 cas de cancers colorectaux
Ziadi, Sonia; Ben Gacen, Riadh; Haoues, Imen et al

in Annales de Biologie Clinique (2011), 69(2), 167-173

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See detailInvestigation of human JC and BK polyomaviruses in breast carcinomas
Hachana, Mohamed Ridha ULg; Amara, Khaled; Ziadi, Sonia et al

in Breast Cancer Research and Treatment (2011)

We have previously showed the presence of the simian virus 40 (SV40) and the mouse mammary tumor virus (MMTV)-like in a significant proportions of Tunisian breast carcinomas. However, to date there are no ... [more ▼]

We have previously showed the presence of the simian virus 40 (SV40) and the mouse mammary tumor virus (MMTV)-like in a significant proportions of Tunisian breast carcinomas. However, to date there are no published studies concerning evaluation of the possible implication of the human polyomaviruses JC (JCV) and BK (BKV) in breast carcinomas. The presence of JCV and BKV DNA was investigated by PCR in a 123 primary breast carcinomas and matched adjacent non-tumor breast tissues. The results were correlated to clinicopathological and virological parameters. JCV T-antigen DNA was detected in 23% of breast carcinoma cases; however, all cases were negative for BKV. JCV T antigen PCR products were further confirmed as authentic JCV genome by direct sequencing. JCV was found in invasive ductal carcinomas (28/112 cases) but not in invasive lobular carcinomas (0/5) or medullary carcinomas (0/6). JCV DNA presence correlates inversely with the expression of estrogen (P = 0.022) and progesterone (P = 0.008) receptors. JCV DNA presence correlates also with "triple negative" phenotype (P = 0.021). With regard to virological data, a trend toward an inverse correlation was noted between the presence of JCV and SV40 (P = 0.06). Moreover, significant correlation was found between multiple viral infection (JCV, and/or SV40, and/or MMTV-like in the same tumor) and "triple negative" phenotype (P = 0.001) and also with p53 accumulation (P = 0.028). To the best of our knowledge, this is the first study demonstrating the presence of JCV in a subset of breast carcinomas. Also our results suggest that "triple negative" breast carcinomas are viral-related tumors. [less ▲]

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See detailInvestigation of Epstein-Barr virus in Tunisian breast carcinomas
Hachana, Mohamed Ridha ULg; Amara, Khaled; Ziadi, Sonia et al

in Pathology - Research & Practice (2011), 207(11), 695-700

Breast carcinoma is a major cause of death among women, and the potential implication of viruses in its pathogenesis remains worth a hypothesis. The potential role of Epstein-Barr virus (EBV) in its ... [more ▼]

Breast carcinoma is a major cause of death among women, and the potential implication of viruses in its pathogenesis remains worth a hypothesis. The potential role of Epstein-Barr virus (EBV) in its pathogenesis is still a subject of continued discussion and investigation. The aim of this study was to evaluate the prevalence of EBV in sporadic breast cancers in Tunisia, and to determine the clinicopathological characteristics of virus-positive cases. Viral presence has been evaluated by polymerase chain reaction (PCR), in situ hybridization, and immunohistochemistry investigated on tumor tissues and their corresponding normal breast tissues collected from 123 Tunisian women with sporadic breast carcinomas. Viral status in tumors was then correlated with various clinicopathological parameters. Using specific PCR assays, EBV DNA was found in 33 (27%) out of 123 breast carcinoma cases. EBV-encoded small RNAs (EBERs) in situ hybridization was negative in the neoplastic cells, but stomal lymphocytes were positive in 4 cases. Immunohistochemistry for latent membrane protein 1 (LMP1) was negative in all cases. None of the normal breast tissues showed positive results for EBV using PCR, in situ hybridization, and immunohistochemistry. A correlation was found between EBV DNA presence and the negativity of estrogen receptor (P=0.008). However, no significant correlation was found for the other parameters investigated, including patient age, Scarff-Bloom-Richardson (SBR) histological grade, tumor size, and histological node involvement. With regard to survival data, overall and disease-free survivals were shorter in EBV-positive breast carcinoma cases than in EBV-negative ones, but this difference did not reach statistical significance. Our study indicates the presence of EBV DNA in a significant proportion of breast cancer in Tunisia. Further studies are required to elucidate the role of this virus in breast carcinogenesis. [less ▲]

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See detailNo evidence of human papillomavirus DNA in breast carcinoma in Tunisian patients
Hachana, Mohamed Ridha ULg; Ziadi, Sonia; Amara, Khaled et al

in Breast (Edinburgh, Scotland ) (2010), 19(6), 541-544

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See detailInvestigation of human papillomavirus in bladder cancer in a series of Tunisian patients
Ben Selma, Walid; Ziadi, Sonia; Ben Gacem, Riadh et al

in Pathology - Research & Practice (2010), 206(11), 740-743

Background: Association between human papillomavirus (HPV) infection and the development of bladder cancer is variable. Furthermore, the prevalence of HPV DNA in bladder carcinoma subtypes varies from ... [more ▼]

Background: Association between human papillomavirus (HPV) infection and the development of bladder cancer is variable. Furthermore, the prevalence of HPV DNA in bladder carcinoma subtypes varies from study to study. To clarify the impact of HPV infection on the development of bladder carcinoma, we performed a retrospective study on Tunisian patients for the status of HPV infection in urothelial carcinoma, squamous cell carcinoma and adenocarcinoma. Methods: A total of 125 formalin-fixed, paraffin-embedded archival tissue of bladder carcinoma were reviewed and classified according to the World Health Organization (WHO) classification of tumors (119 urothelial carcinomas, five squamous carcinomas and one adenocarcinoma). Anogenital HPV DNA detection was performed with three different polymerase chain reaction (PCR) techniques. The first one, using primers pU-2R/pU-1M specific to high-risk oncogenic HPV. The second one, using primers PU-2R/PU-31B specific to low-risk oncogenic HPV and the third one, employing consensus primers (E1-547R/E1-350L). Results: No evidence of HPV infection was detected by morphological examination and PCR in any case of bladder carcinoma. Conclusion: Our study shows that anogenital HPV investigated are not associated with the pathogenesis of bladder cancer in Tunisia, however, the possibility that other subtypes of HPV contribute to bladder carcinogenesis remains to be clarified. [less ▲]

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See detailDNA methyltransferase DNMT3b protein overexpression as a prognostic factor in patients with diffuse large B-cell lymphomas
Amara, Khaled; Ziadi, Sonia; Hachana, Mohamed Ridha ULg et al

in Cancer Science (2010), 101(7), 1722-1730

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See detailPrevalence and characteristics of Epstein-Barr virus-associated gastric carcinomas in Tunisia
Trimeche, Mounir; Ksiâa, Feryel; Ziadi, Sonia et al

in European Journal of Gastroenterology & Hepatology (2009), 21(9), 1001-1007

Objective Epstein–Barr virus (EBV) has been linked to gastric carcinoma (GC) with worldwide geographical variations of prevalence ranging from 1 to 18% of cases. Investigations carried out in north Africa ... [more ▼]

Objective Epstein–Barr virus (EBV) has been linked to gastric carcinoma (GC) with worldwide geographical variations of prevalence ranging from 1 to 18% of cases. Investigations carried out in north Africa have shown that some EBV-associated types of cancers are common in this area. This study was taken to determine the prevalence of EBV-associated GC in Tunisia. Methods Ninety-six nonselected GC cases (male/female ratio 1.7/1, mean age 60.9 years, range: 20–88 years) were evaluated for the presence of EBV by polymerase chain reaction as well as by in-situ hybridization for EBVencoded small RNAs (EBERs) and immunohistochemistry for LMP-1 and EBNA-2 expression. Results EBV was detected by polymerase chain reaction in 36% of cases, whereas EBERs were detected in the tumor cells in only four cases (4.1%). Immunohistochemistry for LMP-1 and EBNA-2 was negative in all cases. The mean age for patients harboring EBERs-positive GC was 55.7 years (range: 52–59 years). All EBERs-positive GC cases were males of advanced clinical stage (pT3–pT4). According to Lauren’s classification, two cases were of diffuse histological type and two cases were of intestinal type. In three cases, the tumors have a proximal location and in the remaining case the tumor arises in the antrum. All EBV strains detected from EBV-associated GC were exclusively of type A and D, prototype F, and XhoI-maintained variant. Conclusion We conclude that the prevalence of EBV-associated GC in Tunisia is low (4.1%), suggesting that this virus is not an important etiological factor in GC arising in north African populations. The clinicopathological profile of EBV-associated GC in Tunisia did not differ markedly from that found elsewhere. [less ▲]

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See detailEvidence for a role of the Simian Virus 40 in human breast carcinomas
Hachana, Mohamed Ridha ULg; Trimeche, Mounir; Ziadi, Sonia et al

in Breast Cancer Research and Treatment (2009), 113(1), 43-58

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See detailPrevalence and characteristics of the MMTV-like associated breast carcinomas in Tunisia
Hachana, Mohamed Ridha ULg; Trimeche, Mounir; Ziadi, Sonia et al

in Cancer Letters (2008), 271(2), 222-230

The involvement of a retrovirus homologous to the mouse mammary tumor virus (MMTV) in the pathogenesis of human breast cancer (BC) has long been assumed, but has never been proven. Previous studies have ... [more ▼]

The involvement of a retrovirus homologous to the mouse mammary tumor virus (MMTV) in the pathogenesis of human breast cancer (BC) has long been assumed, but has never been proven. Previous studies have reported the detection of MMTV-like env sequences in variable proportions that did not exceed 40% of BC cases in several countries. However, these viral sequences have been found in higher proportion (74%) in Tunisian diagnosed with BC during the seventies. This study is an attempt to evaluate the current prevalence of MMTV-like env gene in BC in Tunisian women. We used semi-nested PCR that amplify a 190-bp MMTV-like env sequence, followed by direct sequencing to screen a series of 122 cases of BC randomly selected. The findings were correlated to clinicopathological data and immunohistochemical expression status of progesterone and oestrogen receptors, HER2, and P53. Specific MMTV-like env sequences were found in 17 (13.9%) cases of breast carcinomas, whereas the same sequences were not detected in matched normal breast tissues. The presence of the viral sequences correlates inversely with progesterone receptor expression (6.8% versus 20.3%; P = 0.03) and HER2 overexpression (3.1% versus 17.7%; P = 0.04). This present study confirms the presence of MMTV-like env sequences in BC in Tunisian women but describes an important decrease in the prevalence of the viral sequences compared with pervious studies. This reduction may be due to some changes in the virological characteristics or exposure to the virus. [less ▲]

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See detailPrognostic significance of aberrant promoter hypermethylation of CpG islands in patients with diffuse large B-cell lymphomas
Amara, Khaled; Trimeche, Mounir; Ziadi, Sonia et al

in Annals of Oncology (2008), 19(10), 1774-1786

Background: Diffuse large B-cell lymphoma (DLBCL) exhibits heterogeneous clinical features and a marked variable response to treatment. Patients and methods: We investigated the prognostic significance of ... [more ▼]

Background: Diffuse large B-cell lymphoma (DLBCL) exhibits heterogeneous clinical features and a marked variable response to treatment. Patients and methods: We investigated the prognostic significance of the methylation status of DAPK, GSTP1, P14, P15, P16, P33, RB1, SHP1, CDH1, APC, BLU, VHL, TIMP3, and RASSF1A genes in 46 DLBCL specimens from Tunisian patients. Methylation status of each gene was correlated with clinicopathological parameters including the International Prognostic Index (IPI), the germinal center immunophenotype, and response to treatment and survival. Overall survival (OS) and disease-free survival (DFS) rates were calculated by the Kaplan–Meier method and differences were compared with the log-rank test. Results: Hypermethylation of SHP1 was associated with elevated lactate dehydrogenase level (P = 0.031). P16 and VHL were frequently hypermethylated in patients with high IPI scores (P = 0.006 and 0.004) and a performance status of two or more (P = 0.007 and 0.047). In addition, hypermethylation of P16 was significantly associated with advanced clinical stages and B symptoms (P = 0.041 and 0.012). Interestingly, hypermethylation of DAPK was significantly correlated with resistance to treatment (P = 0.023). With regard to survival rates, promoter hypermethylation of DAPK, P16, and VHL were significantly associated with shortened OS (P = 0.003, 0.001, and 0.017, respectively) and DFS (P = 0.006, 0.003, and 0.046, respectively). In multivariate analysis, hypermethylation of DAPK remains an independent prognostic factor in predicting shortened OS (P = 0.001) and DFS (P = 0.024), as well as the IPI and the germinal center status. Conclusions: This study demonstrates that DLBCLs with hypermethylated P16, VHL, DAPK, and SHP1 commonly show a biologically aggressive phenotype and worse prognosis. Interestingly, hypermethylation of DAPK was found to be an independent prognostic factor that may be used in conjunction with the conventional prognostic factors such as the IPI and the germinal center status. [less ▲]

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See detailProfile of methylaion of tumour related genes in breast cancer in Tunisian women
Hachana, Mohamed Ridha ULg; Trimeche, Mounir; Ziadi, Sonia et al

in European Journal of Cancer (2008), 6(9), 195

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See detailAssociation of Simian Virus 40 (SV40) with human breast carcinomas in Tunisian women
Hachana, Mohamed Ridha ULg; Trimeche, Mounir; Ziadi, Sonia et al

in European Journal of Cancer (2008), 6(9), 195

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See detailContribution de l’inactivation épigénétique des gènes BRCA1 et BRCA2 dans les cancers du sein sporadiques en Tunisie
Trimeche, Mounir; Ziadi, Sonia; Hachana, Mohamed Ridha ULg et al

in Bulletin du Cancer (2008)

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See detailPresence of simian virus 40 DNA sequences in diffuse large B-cell lymphomas in Tunisia correlates with aberrant promoter hypermethylation of multiple tumor suppressor genes
Amara, Khaled; Trimeche, Mounir; Ziadi, Sonia et al

in International Journal of Cancer = Journal International du Cancer (2007), 121(12), 2693-2702

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See detailFréquence de l’hyperméthylation du promoteur du gène BLU dans le cancer du sein en Tunisie
Trimeche, Mounir; Ziadi, Sonia; Hachana, Mohamed Ridha ULg et al

in Bulletin du Cancer (2007)

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