Association between interleuleukin-1ß polymorphism (rs16944) and biomarkers levels in Iraqi patients with prostate cancer.

OBJECTIVE: Prostate cancer (PCa) is the second-leading cause of mortality in men and the most commonly diagnosed non-cutaneous male malignancy. Host genetic factors, and inflammation-induced cytokines, play a key role in prostate oncogenesis. Single Nucleotide Polymorphisms (SNP) in cytokine genes were suggested to increase the susceptibility for PCa development and progression. This study aimed to investigate the association between the SNP (rs16944) in the interleukin-1 ß (IL-1ß) gene and the serum levels of Prostate Specific Antigen (PSA) Prolactine (PRL), testosterone, and IL-1ß in Iraqi PCa patients versus healthy controls. METHODS: Taqman Real Time-PCR, was performed to investigate the IL-1ß (rs16944) polymorphism in 100 Iraqi PCa patients and 50 age-matched healthy controls in a case-control study. Serum levels of PSA, PRL, and testosterone were determined by ELISA and FIA, and associated with the IL-1ß serum level as well as with the SNP (rs 16944). The association between the clinico-pathological parameters and the genotype distribution of PCa patients was also studied. RESULTS: There level of IL-1ß was significant increased in the serum of PCa patients compared to controls (P = 8.19 10-7). Serum levels for other biomarkers such as PSA, PRL and testosterone were also significantly elevated in patients compared to controls (P < 0.0001). No differences were seen for genotype and allele distribution between PCa patients and controls. Nevertheless, in the group of controls, we found that 36% carried the GG genotype against only 26% in the patients group.This suggests that this could be a protective genotype (OR 0.62, P = 0.254). In addition, we found that the GA genotype is slightly more frequent in patients as compared to controls (OR 1.22, P = 0.605). Interestingly, serum levels of IL-1ß, PSA, PRL and testosterone were significantly higher in PCa patients carrying the GA genotype, and the GA and AA genotypes are strongly associated with the aggressive behavior of the disease such as advanced TNM, and high Gleason score. CONCLUSION: Our data suggest that both serum IL-1ß level and IL-1ß SNP (rs16944) may be considered as candidate biomarkers for PCa. Moreover, the GA, and AA genotypes carriers along with high sera levels of IL-1ß, PSA and PRL, have an increased risk for PCa with aggressive behavior in Iraqi men.

Polo-like kinase inhibitor BI2536 induces eryptosis.

BI2536 is potent inhibitor of polo-like kinases PLK1, 2, and 3. The inhibition of PLKs in nucleated cells induces apoptosis by perturbing the cell cycle with consequent engagement of mitotic catastrophe. BI2536 is being tested as chemotherapy in various phase I/II/III clinical trials. Erythrocytes do not have a nucleus; however, they may undergo programmed suicide with characteristic hallmarks including cell shrinkage and phosphatidylserine translocation to the cell surface. This particular death is baptized eryptosis. Our study explored whether BI2536 induces eryptosis. We used flow cytometry to access death in red blood cells. We analyzed the cellular volume, the intracellular calcium concentration, the cell surface phosphatidylserine exposure, and the ceramide abundance. In addition, we analyzed the effect of BI2536 on hemolysis. Our investigation showed that after 48 h of incubation with PLK inhibitor BI2536, erythrocytes lost volume and were positive for annexin­V without any effect on hemolysis. Cells also showed an abundance of ceramide and an increase of intracellular calcium. All these finding suggest that BI2536 provokes eryptosis in red blood cells, ostensibly in part due to Ca2+ entry and ceramide accumulation.

Novel and recurrent BRCA1/BRCA2 germline mutations in patients with breast/ovarian cancer: a series from the south of Tunisia.

BACKGROUND: The incidence of breast cancer (BC) and/or ovarian cancer (OC) is increasing in Tunisia especially in young women and mostly those with family history. However, the spectrum of BRCA mutations remains little explored in Tunisian patients in particular in the southern region. METHODS: We sequenced the entire coding regions of BRCA1and BRCA2 genes using next generation sequencing (NGS) in 134 selected patients with BC and/or OC. RESULTS: Among the 134 patients, 19 (14.17%) carried pathogenic mutations (10 are BRCA1 mutation carriers and 9 are BRCA2 mutation carriers) that are mainly frameshift index (76.9%). Interestingly, 5 out of the 13 variants (38.46%) were found at least twice in unrelated patients, as the c.1310-1313 delAAGA in BRCA2 and the c.5030_5033 delCTAA that has been identified in 4/98 BC patients and in 3/15 OC patients from unrelated families with strong history of cancer. Besides recurrent mutations, 6 variant (4 in BRCA1 and 2 in BRCA2) were not reported previously. Furthermore, 3 unrelated patients carried the VUS c.9976A > T, (K3326*) in BRCA2 exon 27. BRCA carriers correlated significantly with tumor site (p = 0.029) and TNBC cases (p = 0.008). In the groups of patients aged between 31 and 40, and 41-50 years, BRCA1 mutations occurred more frequently in patients with OC than those with BC, and conversely BRCA2 carriers are mostly affected with BC (p = 0.001, and p = 0.044 respectively). CONCLUSIONS: The overall frequency of the BRCA germline mutations was 14.17% in patients with high risk of breast/ovarian cancer. We identified recurrent mutations as the c.1310_1313 delAAGA in BRCA2 gene and the c.5030_5033 delCTAA in BRCA1 gene that were found in 4% and 20% of familial BC and OC respectively. Our data will contribute in the implementation of genetic counseling and testing for families with high-risk of BC and/or OC.

Identification of novel candidate genes by exome sequencing in Tunisian familial male breast cancer patients.

Male Breast Cancer (MBC) is a rare and aggressive disease that is associated with genetic factors. Mutations in BRCA1 and BRCA2 account for 10% of all MBC cases suggesting that other genetic factors are involved. The aim of the present study is to screen whole BRCA1 and BRCA2 exons using the Ampliseq BRCA panel in Tunisian MBC patients with family history. Furthermore, we performed exome sequencing using the TruSight One sequencing panel on an early onset BRCA negative patient. We showed that among the 6 MBC patients, only one (MBC-F1) harbored a novel frameshift mutation in exon 2 of the BRCA2 gene (c.17-20delAAGA, p.Lys6Xfs) resulting in a short BRCA2 protein of only 6 amino-acids. We selected 9 rare variants after applying several filter steps on the exome sequencing data. Among these variants, and based on their role in breast carcinogenesis, we retained 6 candidate genes (MSH5, DCC, ERBB3, NOTCH3, DIAPH1, and DNAH11). Further studies are needed to confirm the association of the selected genes with family MBC.

Association of FOXA1 and EMT markers (Twist1 and E-cadherin) in breast cancer.

The transcription factor FOXA1 (forkhead box A1) plays key roles in tumor development and progression. In the present study, we analyzed the expression of FOXA1 in 52 breast tumors and 10 normal tissues, and investigated the relationship between FOXA1 and two EMT markers, namely Twist1 and E-cadherin by RT-PCR and IHC respectively. The expression level of FOXA1 was higher in tumor compared to normal tissues but the difference was not statistically significant (P = 0.138). FOXA1 expression correlated with less aggressive behavior as SBR grade I (P = 0.04), small tumors size (P = 0.05), and longer survival (P = 0.001). Furthermore, estrogen and progesterone positive tumors exhibit high level of FOXA1 (P = 0.002 and P = 0.038 respectively). Survival analysis showed that patients with ER positive/FOXA1 positive (P log rank = 0.001), PR positive/FOXA1 positive (P log rank = 0.044) and HER-2 negative/FOXA1 positive (P log rank = 0.002) tumors have a significant prolonged overall survival. On the other hand, the expression of E-cadherin positively correlated with FOXA1 (P = 0.028), whereas negative association was seen between the expression of Twist1 and FOXA1 (P = 0.016). Kaplan-Meier plots showed that patients with Twist1negative/FOXA1positive tumors have a significant prolonged overall survival (P log rank = 0.001) and FOXA1 appeared as independent predictors of patient survival in multivariate analyses. Overall, our results indicate that FOXA1 could be a useful biomarker to predict prognosis in breast cancer patients.

Overexpression of miR-10b in colorectal cancer patients: Correlation with TWIST-1 and E-cadherin expression.

MicroRNAs are emergent players of epigenetics that function as oncogenes or tumor suppressors and that have been implicated in regulating diverse cellular pathways. MiR-10b is an oncogenic microRNA involved in tumor invasion and metastasis in various cancers. Our data have shown that miR-10b is overexpressed in colorectal cancer samples in comparison with non-tumorous adjacent mucosa (p = 0.0025) and that it is associated with severe features such as tumor size >5 cm (p = 0.023), distant metastasis (p = 0.0022), non-differentiated tumors (p = 0.016), and vascular invasion (p = 0.01). Regarding the regulation of its expression, positive correlation between the loss of miR-10b and aberrant DNA methylation (p = 0.02) as well as a loss of TWIST-1 messenger RNA (p = 0.018) have been observed. Furthermore, expression analysis of the downstream miR-10b targets has shown that there are associations between low HOXD10 messenger RNA and E-cadherin protein levels (p < 0.0001, p = 0.0008, respectively) and overexpression of miR-10b. Our data suggests that overexpression of miR-10b results from high levels of TWIST-1 and may induce a decrease of E-cadherin membranous protein levels, thus contributing to the acquisition of metastatic phenotypes in colorectal cancer.

Quantitative measurement of iNOS expression in melanoma, nasopharyngeal, colorectal, and breast tumors of Tunisian patients: comparative study and clinical significance.

Chronic inflammation increases the risk of development of human malignancies. iNOS is an enzyme dominantly expressed during inflammatory reactions and seems to play a critical role in tumorigenesis. Our aim was to assess the iNOS expression in four types of human tumors: breast, colorectal, nasopharyngeal, and melanoma, of Tunisian patients. The level of iNOS was measured by RT-QPCR in tumor specimens. We showed that the expression of iNOS was higher in breast compared to colorectal and nasopharyngeal tumors, whereas in melanoma, the level of iNOS expression was low. Significant associations were found when comparing the iNOS expression in cancers pairs such as melanoma versus colorectal (p < 0.0001), colorectal versus nasopharyngeal (p = 0.0072), and melanoma versus breast (p < 0.0001). Furthermore, iNOS expression correlated with the Breslow thickness, Clark level, and histological subtype in melanoma, while in nasopharyngeal carcinoma, significant association was seen with age at diagnosis, TNM, metastasis, response to treatment, and expression of COX-2. Furthermore, the expression of iNOS correlated with tumor size, TNM, tumor location, and histological type in colorectal cancer, and with tumor size, tumor stage, SBR grade, and triple negative cases in breast cancer. On the other hand, immunohistochemistry analysis shows that the expression of iNOS is observed in the stroma and tumor cells as well. Overall, our results highlight that iNOS is a reliable marker for advanced stage and aggressive behavior for the four types of cancer and might be a potential promising therapeutic target.

CpG methylation of ubiquitin carboxyl-terminal hydrolase 1 (UCHL1) and P53 mutation pattern in sporadic colorectal cancer.

The ubiquitin-proteasome system plays an essential regulatory role in various cellular processes. Besides its involvement in normal cellular functions, the alteration of proteasomal activity contributes to the pathological states of several clinical disorders, including cancer. Aberrant methylation of the CpG islands has been reported as an alternative way to inactivate gene expression involved in the ubiquitination process and thus protein degradation in tumor tissues. In this study, we aimed to determine the CpG methylation pattern of the UCHL1 promoter, as well as the mutation spectrum and the expression pattern of P53 in sporadic colorectal cancer (CRC) from Tunisian patients. We found that UCHL1 was methylated in 68.57 % and correlated significantly with lymph node metastasis (P = 0.029) and transcriptional silencing in tumor tissues (P = 0.013). Mutation screening of exons 5-9 of P53 showed that 42.85 % of cases harbor somatic mutation and are positively correlated with the methylated pattern of UCHL1 (P = 0.001). Furthermore, cytoplasmic accumulation of P53 was strongly associated with the unmethylated UCHL1 profile (P = 0.006), supporting the relationship between these two proteins in CRC.

Over-expression of miR-10b in NPC patients: correlation with LMP1 and Twist1.

Aberrant expression of miR-10b has been described in many cancers but remains unexplored in nasopharyngeal carcinoma (NPC). Therefore, we aimed to study the miR-10b expression level in 43 NPC biopsies collected from Tunisian patients and three NPC xenografts. Then, we investigated the correlation between miR-10b expression and its upstream regulators LMP1/Twist1 as well as its adjacent gene HoxD4. We showed that miR-10b was significantly up-regulated in NPC biopsies compared to non-tumor nasopharyngeal tissues (fold change 153; p = 0.004) and associated with advanced clinical stage and young age at diagnosis (p = 0.005 and p = 0.011, respectively). In addition, over-expression of miR-10b was positively associated with the transcription factor Twist1 as well as the EBV oncoprotein LMP1 (fold change 6.32; p = 0.014, fold change 6.58; p = 0.01 respectively). Furthermore, higher level of miR-10b was observed in tumors with simultaneous expression of LMP1 and Twist1, compared to those expressing only Twist1 (fold change 2.49; p = 0.033). Meanwhile, the analysis of the link between miR-10b and its neighbor gene HoxD4 did not show any significant correlation (Fisher test p = 0.205; Mann-Whitney test p = 0.676). This study reports the first evidence of miR-10b over-expression in NPC patients. Furthermore, our findings can support hsa-miR-10b gene regulation through LMP1/Twist1 in NPC malignancy.

Characterization of C69R variant HBsAg: effect on binding to anti-HBs and the structure of virus-like particles.

Several variants of the major "a" determinant of the HBsAg, the main target of HBV neutralization by antibodies, have been described. However, mutations outside this region have not been as thoroughly investigated. During the genotyping of HBV from Tunisian patients with chronic hepatitis B, we identified a variant with a C69R substitution in the cytosolic loop of the S protein, resulting in a change in the hydrophobicity profile compared to the wild-type HBsAg. Wild-type and mutant HBsAgs were produced in Saccharomyces cerevisiae and recombinant proteins were tested for their ability to correctly self-assemble into virus-like particles (VLPs), and their ability to bind to HBs antibodies. The C69R substitution resulted in a decrease in binding to commercial anti-HBs antibodies, and although the variant appeared to assemble properly into VLPs, the average size of the particles was larger than that of the wild-type HBsAg. Prediction of the tertiary structure of the C69R mutant revealed a change in the first (aa 60-70) and the second loop (aa 110 to 120) compared to the wild-type protein. Furthermore, we showed by an isothermal titration calorimetry assay that the interaction between the wild-type HBsAg and the anti-HBs antibody was exothermic, whereas that with the mutant C69R was endothermic, indicating an effect on the binding affinity.

Overexpression of yeast thioredoxin TRX2 reduces p53-mediated cell death in yeast.

We have previously shown that overexpression of the human tumor suppressor protein P53 causes cell death of the yeast Saccharomyces cerevisiae. P53 overproduction led to transcriptional downregulation of some yeast genes, such as the TRX1/2 thioredoxin system, which plays a key role in cell protection against various oxidative stresses induced by reactive oxygen species (ROS). In the present work, the impact of TRX2 overexpression on apoptosis mediated by p53 overexpression in yeast is investigated. In yeast cells expressing P53 under an inducible promoter together with TRX2 under a strong constitutive promoter, we showed that Tr2p overproduction reduced the apoptotic effect exerted by P53 and increased the viability of the P53-overproducing cells. Furthermore, measurements of ROS amounts by flow cytometry and fluorescence microscopy indicated that the TRX2 protein acted probably through its increased detoxifying activity on the P53-generated ROS. The steady-state level and activity of P53 were not affected by TRX2 overexpression, as shown by western blotting and functional analysis of separated alleles in yeast (FASAY), respectively. The growth inhibitory effect of P53 was partially reversed by the antioxidant N-acetylcysteine. Our data strengthen the idea that overexpression of a single gene (trx2) decreases the p53-mediated cell death by decreasing ROS accumulation.

Expression of APC, ß-catenin and E-cadherin in Tunisian patients with gastric adenocarcinoma: clinical significance.

Aberrant activation of the Wnt signalling pathway is a key feature of many cancers. ß-Catenin, adenomatous polyposis coli (APC) and E-cadherin are major players in this pathway. The aim of this study is to examine the expression of ß-catenin, APC and E-cadherin in tumour tissues of 80 Tunisian patients with gastric carcinoma and to determine the methylation status of the APC promoter in tumour tissues. Associations between protein expression and clinico-pathological parameters, including prognosis, were performed. Positive expression of ß-catenin, APC and E-cadherin was observed in 77.5, 68.7 and 60% of cases, respectively. Tumours lacking membranous expression of ß-catenin had greater extent of lymph node metastasis, poor differentiation and advanced T-stage. The expression of E-cadherin correlated with poor differentiation (P = 0.05) and ß-catenin expression (P = 0.004). With regards to prognosis, the overall survival time was significantly prolonged for patients showing normal ß-catenin expression (exclusively or predominantly membranous staining) alone or combined with positive APC expression (P log rank = 0.008 and 0.003, respectively). The methylated pattern of APC promoter 1A was detected in 43.8% of cases and correlated with T-stage (P = 0.046) and distant metastasis (P = 0.037). No correlation was found between the methylated profile of APC promoter 1A and the expression of APC protein in tumour tissues. Our findings suggest that deregulation of the Wnt pathway via abnormal expression of ß-catenin and E-cadherin occurred frequently in gastric carcinoma and correlated with worse clinical behaviour.

Downregulation of WIF-1 and Wnt5a in patients with colorectal carcinoma: clinical significance.

Activation of the wingless-type (Wnt) signaling pathway is common in various human cancers including colorectal cancer (CRC). Wnt inhibitory factor-1 (WIF-1) is a secreted antagonist that can bind Wnt ligands and therefore inhibits the Wnt signaling pathway. In this study, we aimed to analyze the expression of two members of Wnt signaling (WIF-1 and Wnt5a) in Tunisian patients with sporadic CRC. WIF-1 was frequently methylated in tumor tissues (87.95 %) compared to normal mucosa (39.54 %) and correlated with distant metastasis and vascular invasion (P = 0.001 and 0.037, respectively). The unmethylated profile of the WIF-1 promoter conferred a benefit to patients in terms of overall survival (P log rank = 0.024). In addition, in the group of patients with methylated WIF-1 promoter, the overall survival rate was significantly prolonged for those with small tumor size (<5 cm) and absence of distant metastasis (P log rank = 0.007 and 0.036, respectively). Aberrant CpG methylation of the WIF-1 promoter leads to transcriptional silencing of this tumor suppressor gene in tumor tissues (P = 0.001). Furthermore, we showed that the level of Wnt5a mRNA was significantly lower in tumor compared to normal tissues (P = 0.031) and lower still in those showing more aggressive behavior (presence of lymph nodes and advanced TNM stage). Our finding supports that WIF-1 is frequently methylated and that Wnt5a acts as a tumor suppressor gene in CRC. Loss of WIF-1 and Wnt5a functions results in more aggressive behavior of the disease.

Negative control glucose dependent mediated by the PreS2 region on the translation efficiency of the reporter Sh-bleomycin gene in Saccharomyces cerevisiae.

Saccharomyces cerevisiae is able to sense and respond to environmental changes such as the availability of carbon sources. In a previous work, we showed that the expression of the PreS2-S gene of HBV in yeast was negatively regulated at the translational level dependent of glucose. In this study, we show that the S mRNA is detected in the polysomes indicating its active translation, while the PreS2-S mRNA was mainly found in monosomes. Moreover, we used the gene reporter assay based on Zeocin resistance, to better characterize the PreS2 region responsible for this control. Two chimeric genes composed of the N- and C-terminal part of the PreS2 fused to the Sh-bleomycin gene conferring the resistance to Zeocin were expressed in yeast. We found that the strain expressing the N-terminal part of the PreS2 was sensitive to Zeocin on rich medium with 2% glucose. In contrast, the strain harbouring the C-terminal part of the PreS2 fused to the Sh-bleomycin grew on Zeocin, indicating that the Sh-bleomycin mRNA is efficiently translated, subsequently conferring resistance to Zeocin. Our data suggest the establishment of a translational control via the N-terminal part of the PreS2 mediated by the presence of 2% glucose in the media.

A novel PIK3CA hot-spot mutation in breast cancer patients detected by HRM-COLD-PCR analysis.

BACKGROUND: The PI3K protein is involved in the PI3K/AKT/mTOR pathway. Deregulation of this pathway through PIK3CA mutation is common in various tumors. The aim of this work is to identify hotspot mutation at exons 9 and 20 in Tunisian patients with sporadic or hereditary breast cancer. METHODS: Hotspot mutations in exon 9 and exon 20 of the PIK3CA gene were identified by QPCR-High Resolution Melting followed by COLD-PCR and sequencing in 63 (42 sporadic cases and 21 hereditary cases) tumor tissues collected from Tunisian patient with breast cancer. MCF7, and BT20 breast cancer cell lines harboring the PIK3CA hotspot mutations E545K and H1047R in exon 9 and exon 20 respectively, were used as controls in HRM experiments. RESULTS: PIK3CA hotspot mutations were detected in 66.7% (28 out of 42) of sporadic BC cases, and in 14.3% (3 out of 21) of hereditary BC. The E545K and the H1048Y were the most prevalent mutations identified in patients with sporadic and hereditary BC, whereas the H1047R hotspot mutation was not found in our patients. Statistical analysis showed that PIK3CA mutation associated with an aggressive behavior in patients with sporadic BC, while it's correlated with age, tumor stage and tumor size in the group patients with hereditary breast cancer. CONCLUSIONS: Our results showed a novel PIK3CA hotspot mutation in Tunisian breast cancer patients detected by HRM-COLD-PCR. Moreover, the absence of PIK3CA hotspot mutation associated with good prognosis.

Case report: Compound heterozygous variants detected by next-generation sequencing in a Tunisian child with ataxia-telangiectasia.

Ataxia-telangiectasia (A-T) is an autosomal recessive primary immunodeficiency disorder (PID) caused by biallelic mutations occurring in the serine/threonine protein kinase (ATM) gene. The major role of nuclear ATM is the coordination of cell signaling pathways in response to DNA double-strand breaks, oxidative stress, and cell cycle checkpoints. Defects in ATM functions lead to A-T syndrome with phenotypic heterogeneity. Our study reports the case of a Tunisian girl with A-T syndrome carrying a compound heterozygous mutation c.[3894dupT]; p.(Ala1299Cysfs3;rs587781823), with a splice acceptor variant: c.[5763-2A>C;rs876659489] in the ATM gene that was identified by next-generation sequencing (NGS). Further genetic analysis of the family showed that the mother carried the c.[5763-2A>C] splice acceptor variant, while the father harbored the c.[3894dupT] variant in the heterozygous state. Molecular analysis provides the opportunity for accurate diagnosis and timely management in A-T patients with chronic progressive disease, especially infections and the risk of malignancies. This study characterizes for the first time the identification of compound heterozygous ATM pathogenic variants by NGS in a Tunisian A-T patient. Our study outlines the importance of molecular genetic testing for A-T patients, which is required for earlier detection and reducing the burden of disease in the future, using the patients' families.

Strategies for diagnosis and management of CMMRD in low-resource countries: report of a Tunisian family.

Constitutional Mismatch Repair Deficiency (CMMRD) is a rare childhood cancer predisposition syndrome, caused by biallelic pathogenic germline variants in the mismatch repair genes. Diagnosis and management of this syndrome is challenging, especially in low-resource settings. This study describes a patient diagnosed with colorectal cancer and grade 3 astrocytoma at the age of 11 and 12 respectively. Immunohistochemistry analysis showed a loss of MSH2 and MSH6 protein expression in CRC tissues of the patient. We identified by Targeted Exome Sequencing a homozygous pathogenic germline variant in exon 9 of the MSH6 gene (c.3991 C > T; p.Ala1268Glyfs*6). Genetic investigation of the family showed that the father was heterozygous for the identified pathogenic variant while the brother was wild type for this variant. Our study highlights the importance of a correct and timely diagnosis of CMMRD which can have implications for treatment. It also underlines the imperative need to enhance awareness, diagnostic standards, and surveillance that are crucial for patients and their families.

Loss of WIF-1 and Wnt5a expression is related to aggressiveness of sporadic breast cancer in Tunisian patients.

Activation of the Wnt/ß-catenin signaling pathway is common in various human cancers. The aim of this study was to investigate the expression of 2 members of the Wnt family (WIF-1 and Wnt5a) in sporadic and hereditary breast cancer tissues. WIF-1, is a secreted antagonist that binds Wnt ligands, and therefore inhibits the canonical Wnt/ß-catenin pathway. Wnt5a is one of the members of the noncanonical Wnt family that mainly acts through calcium signaling pathway. The expression of WIF-1 was analyzed by methylation-specific PCR and RT-PCR, and the level of Wnt5a ligand was quantified by RT-QPCR in breast cancer tissues. Methylation of WIF-1 was detected in 71.3 % and 81.8 % of sporadic and hereditary cases, respectively. Aberrant methylation of WIF-1 was associated with advanced TNM stage and triple negative cases in sporadic breast carcinoma (p=0.001 and p=0.037, respectively). In hereditary cases, methylation of WIF-1 correlated with age at diagnosis (p=0.027) and p53 status (p=0.035). Regarding patients' survival, WIF-1 methylated promoter conferred a reduced overall survival rate, and particularly in a group of patients with advanced TNM stage (p log rank=0.006). Furthermore, aberrant CpG methylation of the WIF-1 promoter was significantly associated with transcriptional silencing of this tumor suppressor gene in sporadic breast cancer tissues (p=0.036). On the other hand, in sporadic tumor tissues, the level of Wnt5a mRNA was significantly lower compared to normal tissues (p=0.031) and lower still in those showing more aggressive behavior, suggesting that Wnt5a, a ligand involved in the noncanonical Wnt/ß-catenin pathway, could act as a tumor suppressor gene in breast cancer.

Quantitative expression analysis and prognostic significance of the BCL2-associated X gene in nasopharyngeal carcinoma: a retrospective cohort study.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a highly metastatic epithelial malignancy showing high prevalence in Southeast Asia and North Africa. The BCL2-associated X (BAX) gene encodes the most important pro-apoptotic member of the BCL2 family. We have recently shown that BCL2 and BCL2L12, two other members of the same apoptosis-related family, possess significant prognostic value in NPC. The objective of the current study was to analyze BAX mRNA expression in nasopharyngeal biopsies of NPC patients, and to assess its prognostic potential in this disease. METHODS: Total RNA was isolated from 88 malignant and 9 hyperplastic nasopharyngeal biopsies, resected from Tunisian patients. After cDNA synthesis by reverse transcription of polyadenylated RNA, BAX mRNA expression was analyzed using a highly sensitive quantitative real-time polymerase chain reaction (qRT-PCR) method. RESULTS: Lower BAX mRNA levels were detected in NPC biopsies than in hyperplastic nasopharyngeal samples. BAX mRNA expression status was associated with low tumor extent, negative regional lymph node status, and absence of distant metastases. Kaplan-Meier survival analysis demonstrated that patients with BAX mRNA-positive NPC have significantly longer disease-free survival (DFS) and overall survival (OS). In accordance with these findings, Cox regression analysis revealed that BAX mRNA expression can be considered as a favorable prognostic indicator of DFS and OS in NPC, independent of their gender, age, tumor histology, tumor extent, and nodal status. Furthermore, NPC patients without distant metastases are less likely to relapse when their primary tumor is BAX mRNA-positive, compared to metastasis-free patients with a BAX-negative nasopharyngeal malignancy. CONCLUSION: This is the first study examining the potential clinical utility of BAX as a prognostic tumor biomarker in NPC. We provide evidence that BAX mRNA expression can be considered as an independent favorable prognostic indicator of DFS and OS in NPC.

Secreted recombinant P53 protein from Pichia pastoris is a useful antigen for detection of serum p53: autoantibody in patients with advanced colorectal adenocarcinoma.

The detection of P53 alteration by serological method is easier to perform, does not require tumor tissues and is of interest for patients monitoring. In this study, we described the development of a home made ELISA test based on recombinant human P53 protein produced in Pichia pastoris and used as antigen for the detection of serum p53-Abs in colorectal carcinoma patients. The human P53 was secreted as a His-tagged protein by recombinant KM71 strain (Kα21) via the peptide signal α of the Saccharomyces cerevisiae mating type gene. The recombinant P53-His was able to detect p53-Abs in 23.4% of patients. Serum p53-Abs correlated significantly with surgical treatment (P = 0.007), relapse during follow-up (P = 0.036), depth of invasion (P = 0.036) and the level of CA19-9 (P = 0.034). Survival analysis showed that patients negative for serum p53-Abs exhibited a prolonged disease free survival period (P log rank = 0.012). In conclusion, the secreted recombinant human P53-His produced in P. pastoris seems to be a useful antigen for detection of serum p53 Abs in patients with colorectal carcinoma.