Analysis of BRCA1 germline variants (exons 5, 11 and 20) in breast cancer families from Libya.

Breast cancer (BC) is a leading cause of cancer deaths in Libyan women. BRCA1 variants differ globally due to the diversity of genetic makeup and populations history. Their distribution, prevalence, and significance in Libyans remain largely unexplored. This study investigated the characteristics and distribution of BRCA1 variants in exons 5, 11, and 20 in Libyan families with BC. Thirty-six BC patients at ≤ 45 years, between 46-50 years and with a family history of breast, ovarian, pancreatic or prostate cancer in close relatives, or with triple-negative BC, were selected from 33 unrelated families during 2018-2020 at the National Cancer Institute, Sabratha, Libya. From these 33 families, 20 women (18 BC patients and two unaffected) were screened for BRCA1 exons 5, 11 and 20 using Sanger sequencing. All families completed an epidemiology and family history questionnaire. Twenty-seven variants (26 in exon 11 and 1 in exon 20, minor allele frequency of < 0.01) were detected in 10 of 18 unrelated families (55.6%.) Among the 27 variants, 26 (96%) were heterozygous. A frameshift pathogenic variant, c.2643del, and one novel variant c.1366A>G were identified. Furthermore, seven variants with unknown clinical significance were detected: c.1158T>A, c.1346C>G, c.1174C>G, c.3630 G>T, c.3599A>T, and c.3400 G>C in exon 11, and c.5244T>A in exon 20. Six variants with conflicting pathogenicity interpretations, c. 3460T>A, c. 3572 G>A, c. 3700 G>C, c. 1246C>G, c. 1344C>G, and c. 1054 G>A, were also identified. Twelve benign/likely benign variants were identified. Rare BRCA1 variants that have not been reported in North Africa were found in Libyan patients. These findings provide preliminary insights into the BRCA1 variants that could contribute to hereditary BC risk in Libyans. Further functional, computational, and population analyses are essential to determine their significance and potential impact on BC risk, which could ultimately lead to more personalized management strategies.

Arginase is upregulated in healthy women infected by oncogenic HPV types.

INTRODUCTION: The implication of arginase enzyme in Human Papillomavirus (HPV) infections has not been clearly elucidated. The present study investigates whether HPV infection is correlated with changes in plasmatic arginase activity and cervical ARG1 and ARG2 mRNA expression among infected women negative for intraepithelial lesions (NIL). MATERIEL AND METHODS: The present study included 300 women. The plasmatic arginase activity was evaluated by a colorimetric assay. Cervical HPV was detected by real-time PCR. The circulating viral load and ARG1 and ARG2 mRNA expression quantification were performed by quantitative real-time PCR. RESULTS: A significant increase in plasma arginase activity and ARG1 and ARG2 mRNA expression levels in cervical cells was observed among HPV-positive women compared to the HPV-negative group. The highest levels were significantly associated with oncogenic HPV, and increased arginase activity was associated with a high HPV circulating viral load. Moreover, the highest levels of arginase activity were observed in oncogenic HPV-positive inflammatory smears. DISCUSSION: These data suggest that HPV could modulate arginase activity and expression, which may restrict arginine bioavailability and inhibit this amino acid's antiviral properties. CONCLUSION: Our findings revealed that arginase activity and isoform gene expression were upregulated in women with HPV infection, particularly the oncogenic HPV types.

Indoleamine 2,3-dioxygenase gene expression and kynurenine to tryptophan ratio correlation with nasopharyngeal carcinoma progression and survival.

INTRODUCTION: Indoleamine 2,3-dioxygenase (IDO) is an immunosuppressive tryptophan-depleting enzyme expressed in nasopharyngeal carcinoma (NPC) tissue. However, IDO has not been reported in the peripheral blood of NPC patients. The aim of this study was to analyze, IDO1 and IDO2 messenger RNA (mRNA) expression, the kynurenine (Kyn) and tryptophan (Trp) plasma levels, their clinical values and their relationship with cytokine levels in NPC. METHODS: We evaluated IDO1 and IDO2 mRNA expression in peripheral blood mononuclear cells (PBMC) by quantitative real-time PCR, plasma Trp and Kyn levels by HPLC, and cytokine levels by ELISA in 75 NPC patients and 51 healthy controls. RESULTS: Compared to controls, IDO1 mRNA expression was significantly upregulated and IDO2 mRNA expression was significantly downregulated in PBMC of patients. Also compared to controls, plasma Kyn levels and Kyn/Trp ratio were significantly higher in patients. At the time of diagnosis, the plasma Kyn/Trp ratio was associated with advanced cancer status and was an independent prognostic factor for worse disease-specific survival. According to cancer stages, IDO1 mRNA expression was positively correlated with plasma Kyn/Trp ratio in patients with earlier stages (I-II-III) but negatively correlated in patients with the late-stage cancer (IV). Tumor necrosis factor-α, interleukin (IL)-6 and IL-10 levels were significantly higher in patients compared to controls. Moreover, and despite treatment, patients simultaneously carrying high plasma Kyn/Trp ratio and high plasma IL-6 and IL-10 levels at diagnosis died approximately 1 year after first diagnosis. CONCLUSION: Measuring blood IDO mRNA expression and Kyn/Trp ratio at diagnosis could be a potential marker to evaluate NPC progression and predict survival outcome.

Arginase is involved in cervical lesions progression and severity.

BACKGROUND: Little is known about the relationship between arginase, an immunosuppressive enzyme, and cervical lesions. The present study is aimed at evaluating arginase activity in plasma and mRNA arginase isoforms expression in cervical cells of patients with abnormal cytology and identifying their relationship with Human papillomavirus (HPV) related parameters such as: HPV type, HPV circulating viral load and anti-HPV16 IgG. METHODS: This study included 77 women with cervical lesions and 95 matched controls. Arginase activity was detected by colorimetric assay. Arginase mRNA expression and HPV viral load were evaluated by quantitative real time PCR and anti-HPV16 antibodies were assessed by ELISA. RESULTS: Compared to controls, the arginase activity was higher among women with cervicitis / low grade squamous intraepithelial lesions (LSIL) (OR: 1.872, 95% CI: 0.833-4.210), and also among women with high-grade squamous intraepithelial lesions (HSIL) / squamous cell carcinoma (SCC) (OR: 3.358, 95% CI: 1.670-8.910). Compared to controls, mRNA expression was significantly upregulated in women with cervical cervicitis and SIL for ARG1, and in women with cancer lesions for ARG2. Arginase activity was positively correlated to ARG2 mRNA expression but not to ARG1. High arginase activity was associated with HPV16, high levels of HPV viral load, and low levels of anti-HPV16 antibodies. CONCLUSIONS: Our findings demonstrated that arginase activity and isoforms expression were enhanced in women with HPV-related precancerous lesions and cervical cancer. Further studies are needed to identify how arginase enzyme induces disease progression and severity.

Prevalence of antibodies against a cyclic peptide mimicking the FG loop of the human papillomavirus type 16 capsid among Tunisian women.

BACKGROUND: In the past decade, cervical cancer has gone from being the second to the fourth most common cancer in women worldwide, but remains the second most common in developing countries. This cancer is most commonly caused by high-risk types of human papillomavirus (HPV), mainly type 16 (HPV16), which are sexually transmitted. This study aimed to investigate the usefulness of a cyclic synthetic peptide designed from the major L1 capsid protein of HPV16 for detecting anti-HPV16 antibodies. METHODS: We designed and synthetized a peptide that corresponds to the full sequence of the surface-exposed FG loop. We tested the antigenicity of the linear and the cyclic peptides against HPV16 L1 monoclonal antibodies. We used ELISA to detect anti-peptide antibodies in sera and cervical secretions of 179 Tunisian women, and we applied polymerase chain reaction and direct sequencing methods to detect and genotype HPV DNA. RESULTS: Both the linear and the cyclic peptides were recognized by the same neutralizing monoclonal antibodies, but the cyclic peptide was more reactive with human sera. The prevalence of the anti-peptide antibodies in sera was higher in women with low-grade squamous intraepithelial lesions (LGSIL) than in women with high-grade squamous intraepithelial lesions (HGSIL) (44% and 15%, respectively). This contrasts with HPV16 DNA prevalence. Compared to women from the general population, systemic IgG prevalence was significantly higher among sex workers (25%; P = 0.002) and women with LGSIL (44%; P = 0.001). In addition, systemic IgA and cervical IgG prevalence was higher among sex workers only (P = 0.002 and P = 0.001, respectively). We did not observe anti-peptide IgG antibodies in women with a current HPV16 infection. CONCLUSION: Anti-peptide IgG in sera or in cervical secretions could be markers of an effective natural immunization against HPV16. This may open novel perspectives for monitoring vaccinated women and for the design of synthetic peptide-based vaccines.

Contribution of BRCA1 5382insC mutation in triple negative breast cancer in Tunisia.

BACKGROUND: Triple negative breast cancer (TNBC) has been classified as a disease subgroup defined by the lack of expression of estrogen and progesterone receptors as well as the absence of the human epidermal growth factor receptor-2 (HER2) overexpression. Germline mutations in the BRCA1 gene have been associated with TNBC. Approximately 70% of breast cancers arising in BRCA1 mutation carriers and up to 23% of breast cancers in BRCA2 carriers display a triple negative phenotype. However, the contribution and the frequency of BRCA1 mutations in individuals with TNBC, not specifically selected for age at diagnosis or enriched family history of breast/ovarian cancer, have not been investigated in the Tunisian population and are to be established. The aim of the present study was to assess the contribution and the prevalence of recurrent BRCA1 germline mutation (5382inC) in Tunisian women with TNBC unselected for family history or age at onset. METHODS: For BRCA1 5382inC mutation detection, the exon 20 coding region and exon-intron boundaries of BRCA1 was analyzed using direct DNA sequencing. A total of 33 DNA samples from Tunisian women diagnosed with TNBC and unselected for family history or age at onset were analyzed. RESULTS: The 5382inC mutation was identified in 2 out of 33 women with TNBC with an overall prevalence of 6% (2/33). The detection rate of the 5382inC mutation among TNBC women with family history of breast cancer was 25% (2/8). The two 5382inC mutation carriers were postmenopausal and diagnosed at the age of 50 and 57. When stratified by age, the frequency of BRCA1 mutation in patients diagnosed at age ≥ 50 years was 8.7% (2/23). CONCLUSIONS: Our results confirm a noticeable contribution of BRCA1 5382inC mutation in TNBC development in Tunisia and further indicate that screening for 5382insC mutation in the BRCA1 gene is of interest in genetic testing in our population. Additionally, our data highlight that receptor triple negativity could be an effective selection criterion for BRCA1 genetic test in our population and should therefore be considered in genetic testing guidelines in Tunisia.

Contribution of Nitric oxide synthase 3 genetic variants to nasopharyngeal carcinoma risk and progression in a Tunisian population.

PURPOSE: We conduct this study to evaluate the clinical and functional impact of Nitric Oxide Synthase 3 (NOS3) T-786C and G894T genetic variants on nasopharyngeal carcinoma (NPC) risk and progression in a Tunisian population. METHODS: 259 NPC patients and 169 healthy controls were enrolled into our case-control study. Blood samples were genotyped by the RFLP-PCR analysis. The levels of Nitric oxide (NO) were measured by a colorimetric assay kit in the plasma of NPC patients, healthy controls and according to NOS3 genotypes. The correlation between the NOS3 variants and the clinicopathological parameters was examined. RESULTS: We found no linkage disequilibrium between NOS3 T-786C and G894T variants. These results showed that NOS3 variants were genetically independent. In contrast to NOS3 T-786C, a significant association was found between NOS3 G894T polymorphism and NPC risk. The 894T allele decreased significantly in NPC patients and appeared as protective factor (OR = 0.65, CI 95%= 0.48-0.88, p = 0.006). NPC patients had significantly higher levels of plasma NO as compared to healthy controls (p = 0.0011). The T-786C mutation reduced the levels of plasma NO and decreased risk of lymph node metastasis in NPC patients (OR = 0.64, 95% CI = 0.43-0.96; p = 0.03). In contrast, NOS3 G894T polymorphism had no effects neither on NO plasma levels nor clinical parameters. CONCLUSIONS: This is the first study to associate NPC with significantly higher levels of plasma NO. NOS3-derived NO could play key roles in NPC pathogenesis. NOS3 variants differently contribute to NPC risk and progression in a Tunisian population. NOS3 G894T was associated with NPC risk. NOS3 T-786C decreased the levels of plasma NO and reduced the development of regional lymph node metastasis.

Government Ownership and Adaptation in Scale-Up: Experiences from Community-Based Family Planning Programme in the Democratic Republic of the Congo.

A systematic approach to scale-up was applied to expand an integrated package of family planning and primary healthcare services from the Democratic Republic of the Congo's South Kivu province to health zones in Lomami, Lualaba, and Kasai Central provinces. This approach was based on recommendations from the ExpandNet/WHO guide Beginning with the end in mind. The approach emphasized application of three recommendations: engaging government stakeholders, ensuring the relevance of the intervention, and tailoring the innovation to the setting. This approach led to successful scale-up of community-based family planning, increasing access to and uptake of contraception and demonstrating potential for sustainability; 231,566 new acceptors were recruited and 149,826 couple-years of protection were generated. The systematic scale-up approach led to integration of community-based family planning indicators in the national health information system and transferred ownership of the interventions to the government, creating and strengthening government platforms with potential to sustain the interventions.

Joint effect of smoking and NQO1 C609T polymorphism on undifferentiated nasopharyngeal carcinoma risk in a North African population.

BACKGROUND: Nasopharyngeal carcinoma (NPC) has a higher incidence in North Africa than in most parts of the world. In addition to environmental factors such as Epstein-Barr virus infection and chemical carcinogen exposure, genetic susceptibility has been reported to play a key role in the development of NPC. NAD(P)H: quinone oxidoreductase 1 is a cytosolic enzyme that protects cells from oxidative damage. A C to T transition at position 609 in the NQO1 gene (OMIM: 125860) has been shown to alter the enzymatic activity of the enzyme and has been associated with increased risk to several cancers. This study investigates for the first time the effect of this polymorphism on NPC susceptibility in a North African population. METHODS: The NQO1 C609T polymorphism was genotyped using PCR-RFLP in 392 NPC cases and 365 controls from Morocco, Algeria, and Tunisia. RESULTS: The allele frequencies and distributions of genotypes did not differ between cases and controls (p > 0.05). When stratifying according to smoking status, we observed two-fold higher NPC risk in ever-smokers carrying the CT or TT genotype. Multiple logistic regression analysis revealed that there was a significant interaction between T allele and smoking status (OR = 1.95, 95% CI = 1.20-3.19; interaction p = 0.007). CONCLUSION: In this North African population, the functional NQO1 polymorphism was associated with a significantly higher risk of NPC among smokers and did not affect the risk among nonsmokers.

Establishing a Multicenter Longitudinal Clinical Cohort Study in Ethiopia: Advanced Clinical Monitoring of Antiretroviral Treatment Project.

BACKGROUND: The purpose of this paper is to describe the establishment of the Advanced Clinical Monitoring of ART Project in Ethiopia for monitoring and evaluation of the longitudinal effectiveness of the ART program and to show the opportunities it presents. This cohort was established in response to the 2005 call by WHO for establishing additional mechanisms for stronger monitoring of ART and the need for creating the platform to generate evidence to guide the care given for the ever increasing number of patients on ART in Ethiopia. METHOD: A participatory and multi-stage process which started from a consensus building workshop and steered by a mother protocol as well as guiding documents which dictated the degree of engagement and expectations was followed. The primary and secondary aims of the study were agreed upon. A multi-site longitudinal observational clinical cohort was established by a consortium of stakeholders including seven Ethiopian medical schools and their affiliated referral hospitals, John Hopkins University, Ethiopian Public Health Institute, Ministry of Science and Technology, US Centers for Disease Prevention and Control - CDC-Ethiopia, and the Federal Ministry of Health. Adult and adolescent cohorts covering the age range of 14+ years) and pediatric cohorts covering those below age 14 years were the two main cohorts. During the initial recruitment of these cohorts information was extracted from existing documents for a total of 2,100 adult participants. In parallel, a prospective cohort of 1,400 adult and adolescent patients were enrolled for ART initiation and follow-up. Using similar recruitment procedures, a total of 120 children were enrolled in each of retrospective and prospective cohorts. Replacement of participants were made in subsequent years based on lost follow up and death rates to maintain adequacy of the sample to be followed-up. ACHIEVEMENTS: Between January 2005 and August 2013 a total of 4,339 patients were followed for a median of 41.6 months and data on demographic characteristics, baseline and ongoing clinical features, hospitalization history, medication and laboratory information were collected. 39,762 aliquots and 25,515 specimens of plasma and dryblood-spots respectively were obtained and stored longitudinally from October 2009 to August 2013. The project created a research platform for researchers, policy and decision makers. Moreover, it encouraged local and international investigators to identify and answer clinically and programmatically relevant research questions using the available data and specimens. Calls for concept notes paired with multiple trainings to stimulate investigators to conduct analyses further boosted the potential for doing research. CONCLUSIONS: A comprehensive and resourceful mechanism for scientific inquiry was established to support the national HIV/ART program. With meaningful involvement and defined roles, establishment of a study, which involved multiple institutions and investigators, was possible. Since ACM is the largest multi-site clinical cohort of patients on antiretroviral treatment in Ethiopia-which can be used for research and for improving clinical management-considering options to sustain the project is crucial.

E-cadherin genetic variants predict survival outcome in breast cancer patients.

BACKGROUND: E-cadherin is a major component of adherens junctions that regulates cell shape and maintains tissue integrity. A complete loss or any decrease in cell surface expression of E-cadherin will interfere with the cell-to-cell junctions' strength and leads to cell detachment and escape from the primary tumor site. In this prospective study, three functional single nucleotide polymorphisms (-347G/GA, rs5030625; -160C/A, rs16260; +54C/T, rs1801026), were found to modulate E-cadherin expression. METHODS: 577 DNA samples from breast cancer (BC) cases were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: We detected no significant correlations between each polymorphism and the clinical parameters of the patients whereas the GACC haplotype was significantly associated with low SBR grading. Overall survival analysis showed that both -347G/G and +54C/C wild (wt) genotypes had a significantly worse effect compared to the other genotypes (non-wt). Moreover, carrying simultaneously both the -347 and +54 wt genotypes confers a significantly higher risk of death. However, with metastatic recurrence, the death-rate was null in patients carrying the non-wt genotypes, and attained 37% in those carrying the wt genotype. A multivariate analysis showed that these two polymorphisms are independent prognostic factors for overall survival in BC patients. CONCLUSIONS: Our results support the fact that E-cadherin genetic variants control disease severity and progression and could be a marker of disease outcome. These findings could be useful in selecting patients that should be monitored differently.

No association between TGF-ß1 polymorphisms and risk of nasopharyngeal carcinoma in a large North African case-control study.

BACKGROUND: Genetic susceptibility plays a key role in the development of nasopharyngeal carcinoma (NPC) and in fact the disease presents with an unusually high incidence in certain regions of the world like North Africa. We investigated the association between polymorphism of the Transforming growth factor-ß1 (TGF-ß1) and risk of NPC in North Africa. TGF-ß1 is a multifunctional cytokine that acts as both a tumor suppressor and a stimulator of cancer development; it has been shown to influence risk of numerous other carcinomas including lung, breast and prostate cancer. METHODS: TGF-ß1 polymorphisms C-509T and T869C were studied in a large North African sample of 384 NPC cases and 361 controls, matched for age, sex and urban or rural residence in childhood. Genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism. RESULTS: No association was observed between individual single nucleotide polymorphisms or their haplotypes and NPC susceptibility (for TGF-ß1 C-509T: OR = 0.74; 95 % CI 0.46 - 1.18; for TGF-ß1 T869C: OR = 0.86; 95 % CI 0.56 - 1.31), even when the samples were stratified by age, gender and TNM stage. CONCLUSION: Contrary to what has been observed in Asian samples, in our North African sample, the TGF-ß1 C-509T and T869C polymorphisms did not substantially influence NPC susceptibility.

Prognostic value of indoleamine 2,3-dioxygenase activity and expression in nasopharyngeal carcinoma.

Indoleamine 2,3-dioxygenase (IDO) is an enzyme with an immunosuppressive effect whose function is diverted by tumor cells to counteract immune cell functions, inducing immune escape of tumor cells. The aim of this study was to investigate the clinical significance of IDO in nasopharyngeal carcinoma (NPC). Compared to controls, NPC patients' plasma IDO activity was significantly higher, especially among patients with metastatic cancer (p=0.005). The immunohistochemical analysis revealed that high IDO expression was observed in 74% of NPC tissues and the epithelial IDO expression was inversely correlated to T-cell infiltration. Kaplan-Meier survival analysis showed that whatever the localization, intratumoral or stromal, patients with a high IDO expression and low T-cell infiltration have significantly lower survival rates. Moreover, in multivariate analysis, intratumoral and stromal IDO expression were found to be independent prognostic factors for disease-free survival (p=0.016; HR: 3.52) and overall survival (p=0.015; HR: 4.76) respectively. Our findings provide evidence that IDO is involved in tumor immune evasion of NPC, suggesting that it could be a relevant therapeutic target for NPC.

Molecular epidemiology and genotype distribution of Human Papillomavirus (HPV) among Arab women in the State of Qatar.

BACKGROUND: Human Papilloma Virus (HPV) infection is the major cause of cervical cancer worldwide. With limited data available on HPV prevalence in the Arab countries, this study aimed to identify the prevalence and genotypic distribution of HPV in the State of Qatar. METHODS: 3008 cervical samples, exclusively of women with Arabic origin residing in Qatar were collected from the Women's Hospital and Primary Health Care Corporation in Doha, State of Qatar. HPV DNA detection was done using GP5+/6+ primers based real time-polymerase chain reaction (RT-PCR) assay followed by the usage of HPV type specific primers based RT- PCR reactions and Sanger sequencing for genotype identification. RESULTS: Similar prevalence rates of HPV infection was identified in both Qatari and non-Qatari women at 6.2% and 5.9% respectively. HPV prevalence rate of 5.8% and 18.4% was identified in women with normal cytology and in women with abnormal cytology respectively. HPV 81, 11 and 16, in decreasing order were the most commonly identified genotypes. HPV 81 was the most frequent low-risk genotype among women with both normal (74.0%) and abnormal (33.3%) cytology. HPV 16 (4.6%) was identified as the predominant high-risk HPV genotype among women with normal cytology and HPV 16, HPV 18, and HPV 56 (22.2% each) were the most common identified high-risk genotypes in women with abnormal cytology. CONCLUSIONS: The overall HPV prevalence in Arab women in Qatar was identified as 6.1% with an increased HPV prevalence seen in women with abnormal cytology results and no significant trends seen with age. In contrast to Western countries, we report a varied genotypic profile of HPV with a high prevalence of low-risk HPV genotype 81 among the Arab women residing in Qatar.

Genome-Wide Association Studies (GWAS) breast cancer susceptibility loci in Arabs: susceptibility and prognostic implications in Tunisians.

Genome-wide Association Studies (GWAS) revealed novel genetic markers for breast cancer susceptibility. But little is known about the risk factors and molecular events associated with breast cancer in Arab Population. Therefore, we designed a broad study to investigate the susceptibility and prognostic implications of the GWAS breast cancer loci in the Tunisian population. In a cohort of 640 unrelated patients with breast cancer and 371 healthy control subjects, we characterized the variation of 9 single nucleotide polymorphisms (SNPs), namely rs1219648, rs2981582; rs8051542, rs12443621, and rs3803662; rs889312; rs3817198; rs13387042 and rs13281615. Only 5 out of 9 GWAS breast cancer loci were found to be significantly associated with breast cancer in Tunisians: The rs1219648 (G vs. A allele: OR = 1.36, P = 1 × 10(-3)) and rs2981582 (A vs. G allele: OR = 1.55, P = 3 × 10(-6)) of FGFR2 gene; the rs8051542 of the TNRC9 gene (T vs. C allele: OR = 1.40, P = 4 × 10(-4)); the rs889312 of the MAP3K1 gene (C vs. A allele: OR = 1.33, P = 3 × 10(-3)) and the rs13281615 located on 8q24 (G vs. A allele: OR = 1.21, P = 0.03). Homozygous variant genotypes of rs2981582 were strongly related to lymph node negative breast cancer (OR = 3.33, P = 6 × 10(-7)) and the minor allele of rs2981582 was associated with increased risk of ER+ tumors (OR = 1.57, P = 0.02; OR = 2.15, P = 0.001, for heterozygous and homozygous variant genotypes, respectively) and increased risk of distant metastasis development (OR = 2.30, P = 4 × 10(-3); OR = 3.57, P = 6 × 10(-5), for heterozygous and homozygous variant genotypes, respectively) in a dose dependent manner. The association for rs8051542 was stronger for high-grade SBR tumors (OR = 2.54, P = 2 × 10(-4)). GG genotype of rs13387042 on 2q35 showed a significant association with the risk of developing distant metastasis (OR = 1.94, P = 0.02). The G allele of rs1219648 in FGFR2 and the A allele of rs13387042 on 2q35 indicated a better prognosis by showing a significantly higher overall survival rates (P = 0.013 and P = 0.005, respectively). In conclusion, GWAS breast cancer FGFR2, TNRC9, MAP3K1, and 8q24 loci are associated with an increased risk of breast cancer and genetic variation in FGFR2 gene may predict the aggressiveness of breast cancer in Tunisians.

Hereditary breast cancer in Middle Eastern and North African (MENA) populations: identification of novel, recurrent and founder BRCA1 mutations in the Tunisian population.

Germ-line mutations in BRCA1 breast cancer susceptibility gene account for a large proportion of hereditary breast cancer families and show considerable ethnic and geographical variations. The contribution of BRCA1 mutations to hereditary breast cancer has not yet been thoroughly investigated in Middle Eastern and North African populations. In this study, 16 Tunisian high-risk breast cancer families were screened for germline mutations in the entire BRCA1 coding region and exon-intron boundaries using direct sequencing. Six families were found to carry BRCA1 mutations with a prevalence of 37.5%. Four different deleterious mutations were detected. Three truncating mutations were previously described: c.798_799delTT (916 delTT), c.3331_3334delCAAG (3450 delCAAG), c.5266dupC (5382 insC) and one splice site mutation which seems to be specific to the Tunisian population: c.212 + 2insG (IVS5 + 2insG). We also identified 15 variants of unknown clinical significance. The c.798_799delTT mutation occurred at an 18% frequency and was shared by three apparently unrelated families. Analyzing five microsatellite markers in and flanking the BRCA1 locus showed a common haplotype associated with this mutation. This suggests that the c.798_799delTT mutation is a Tunisian founder mutation. Our findings indicate that the Tunisian population has a spectrum of prevalent BRCA1 mutations, some of which appear as recurrent and founding mutations.

Combined effect of pro- and anti-inflammatory cytokine gene polymorphisms on susceptibility to liver cirrhosis in Tunisian HCV-infected patients.

PURPOSE: Chronic hepatitis C progression is commonly attributed to the continuous activation of the immune response with an increased production of pro-inflammatory cytokines, leading to fibrosis and ultimately to cirrhosis. On the contrary, anti-inflammatory cytokines, mainly interleukin (IL)-10 have a modulatory effect on hepatic fibrogenesis. The association between individual polymorphisms within cytokine genes and hepatitis C outcome is often weak and non-informative. Interestingly, it has been demonstrated that a combination of specific genotypes may be a more significant and powerful approach for predicting disease risk. AIM: This study is aimed at investigating the combined effect of single nucleotide polymorphism (SNP) in IL-18 (-607C/A, -137G/C), interferon (IFN)-γ (+874T/A) and IL-10 (-1082G/A) genes on cirrhosis risk in HCV-infected patients. METHODS: Seventy-seven chronic hepatitis C Tunisian subjects were included in this study. The patients were divided into two groups: the first included 31 non-cirrhotic patients, and the second included 46 liver cirrhosis patients. IL-18 genotyping was performed using the PCR amplification and the restriction fragment length polymorphism analysis (RFLP). IFN-γ and IL-10 polymorphisms were analyzed using the allele-specific PCR (AS-PCR). RESULTS: The combined high-risk genotype (IL-18 -607C/*, IL-18 -137G/*, IFN-γ +874T/*, IL-10 -1082A/A) frequency was compared between patients with and those without cirrhosis. Individuals were classified according the number of high-risk genotypes as follows: (0-2), patients with at most two high-risk genotypes; (3-4), patients with at least three of the high-risk genotypes. The logistic regression analysis showed that patients harboring 3-4 putative high-risk genotypes have a fivefold higher risk for developing cirrhosis in comparison to those harboring at most two high-risk genotypes (OR = 5.19; 95% CI = 1.49-18.05; p = 0.009). CONCLUSION: Our study showed that the co-inheritance of IL-18, IFN-γ and IL-10 specific high-risk genotypes is associated with a greater risk for liver cirrhosis.

Epstein-Barr virus DNA quantification and follow-up in Tunisian nasopharyngeal carcinoma patients.

The prognostic value of the Epstein-Barr virus (EBV) DNA load in sera of nasopharyngeal carcinoma (NPC) patients measured before any treatment, after treatment and before relapse was assessed. The real-time polymerase chain reaction was used to detect the viral load levels among 74 NPC subjects. Patients were followed up for a period going from 1 to 6 years (median 4 years). Before treatment, the EBV DNA load was correlated with lymph node involvement and advanced stages. After treatment, the viral load level declined significantly and patients presenting a viral load level lower than 1000 copies/ml showed a better overall survival (OS). Moreover, a significant result was found when the 6-year OS rates of patients having fewer or more than 15,000 copies/ml of viral load before relapse were compared. These results suggest that the EBV DNA load quantification after treatment may be a useful predictor of disease progression and survival.

Lack of association between human leukocyte antigen-E alleles and nasopharyngeal carcinoma in Tunisians.

Nasopharyngeal carcinoma (NPC), a cancer with a remarkable geographical and worldwide ethnic distribution, has been strongly associated with human leukocyte antigen (HLA) class I genes. The presence of additional HLA risk factors has been suggested by several reports. In the present study, we analyzed the implication of HLA-E gene polymorphisms in NPC susceptibility in Tunisians, a population characterized by an intermediate incidence of NPC with specific clinical features. Peripheral blood DNA was obtained from 185 patients with NPC and 177 matched controls. Genotyping for three single-nucleotide polymorphisms, codon 83Gly/Arg, codon 157Arg/Gly, and codon 107Arg/Gly, was performed using the polymerase chain reaction method. The HLA-E*01:01 and HLA-E*01:03 were the only alleles found among Tunisians. The HLA-E*01:03 allele had a slight increase in patients with NPC (43%) compared with controls (37%), but the difference did not reach a statistical significance. Our results show the lack of association between HLA-E alleles and NPC in the Tunisian population. This is not in agreement with the previous studies, suggesting a potential implication of HLA-E gene polymorphisms in the susceptibility to NPC among populations with high-risk incidence. Our study further supports the dissimilarity of NPC between populations with different NPC incidence.

Slower clearance of nevirapine resistant virus in infants failing extended nevirapine prophylaxis for prevention of mother-to-child HIV transmission.

Nevirapine resistance mutations arise commonly following single or extended-dose nevirapine (ED-NVP) prophylaxis to prevent mother-to-child transmission (PMTCT) of human immunodeficiency virus (HIV), but decay within 6-12 months of single-dose exposure. Use of ED-NVP prophylaxis in infants is expected to rise, but data on decay of nevirapine resistance mutations in infants in whom ED-NVP failed remain limited. We assessed, in Ethiopian infants participating in the Six-Week Extended Nevirapine (SWEN) Trial, the prevalence and persistence of nevirapine resistance mutations at 6 and 12 months following single-dose or up to 6 weeks of ED-NVP, and correlated their presence with the timing of infection and the type of resistance mutations. Standard population genotyping followed by high-throughput cloning were done on dried blood spot samples collected during the trial. More infants who received ED-NVP had nevirapine resistance detected by standard population genotyping (high frequencies) at age 6 months compared with those who received single-dose nevirapine (SD-NVP) (58% of 24 vs. 26% of 19, respectively; p = 0.06). Moreover, 56% of ED-NVP-exposed infants with nevirapine resistance at age 6 months still had nevirapine resistance mutations present at high frequencies at age 1 year. Infants infected before 6 weeks of age who received either SD- or ED-NVP were more likely to have Y181C or K103N; these mutations were also more likely to persist at high frequencies through 1 year of age. HIV-infected infants in whom ED-NVP prophylaxis fails are likely to experience delayed clearance of nevirapine-resistant virus in the first year of life, which in turn places them at risk for early selection of multidrug-resistant HIV after initial therapy with nonnucleoside reverse transcriptase inhibitor-based regimens.