Sabrina Zidi

The relationship between TNF alpha gene polymorphisms (-238/-308), TNF RII VNTR (p75) and outcomes of hepatitis B virus infection in Tunisian population.

The present study was undertaken to investigate the association between Hepatitis B Virus (HBV) infection and polymorphisms of tumour necrosis factor alpha TNF-α -308 G>A, TNF-α -238 G>A and TNF RII VNTR (p75) gene promoter in a Tunisian population. Blood samples were collected from 100 Tunisian patients with HBV infection, 45 with Chronic Hepatitis (CH), 36 with Liver Cirrhosis (LC), 15 with Hepatocellular Carcinoma (HCC) and 200 healthy individuals of similar ethnicity. Genomic DNA was extracted from peripheral blood leukocytes. Genotyping of the analysed polymorphisms was performed using Amplified Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR), Restriction Fragment Length Polymorphism (RFLP) and Variable Number Tandem Repeat PCR (PCR-VNTR). The variant homozygotes -308 GG were associated with 50% decreased risk of HBV chronic infection (GG vs AA+GA; p=0.010; OR=0.50; 95%CI=0.29-0.85). However, the carriers of minor allele -308 A have higher risk (1.5 times) to develop a chronic infection than other patients (p=0.027; OR=1.46; 95%CI=1.04-2.06). The minor allele of -238 polymorphism was positively associated with virus resistance and the development of chronic infection (p=0.043; OR=1.42; 95%CI =1.01 1.99). The distribution of -308, -238 and TNF RII VNTR (p75) among the three groups differed significantly. For HCC groups, there were statistically significant differences in allele distribution in -308, -238 respectively in which A allele remains a risk factor for HBV evolution to HCC (p=0.008 and p=0.026). Haplotype analysis revealed that TNF-α (-308A; -238A) was significantly associated to HBV chronic infection and moreover to disease aggravation to HCC stage. Our findings imply that variations in the genes governing the levels of constitutive and inducible TNF-α and TNF RII might be an important risk factor, which could explain the variable outcomes of HBV infection.

Relationship of common vascular endothelial growth factor polymorphisms and haplotypes with the risk of cervical cancer in Tunisians

OBJECTIVE We investigated the association between common vascular endothelial growth factor (VEGF) single nucleotide polymorphisms (SNPs) and the risk of cervical cancer (CC) in Tunisian patients and control women. METHODS Study subjects comprised 86 CC cases and 124 control women. Genotyping of VEGF rs699947, rs833061, rs1570360, rs2010963, rs25648, rs833068, rs833070, rs3025039 SNPs was done by real-time PCR. RESULTS Higher minor allele frequencies (MAF) of rs699947 (-2578C/A) [P=0.04; OR (95% CI)=1.52 (1.02-2.29)], and rs1570360 (-1154G/A) [P=0.04; OR (95% CI)=1.58 (1.01-2.47)] were seen in CC cases compared to control women. Marked differences in the distribution of rs699947 (P=9×10(-4)) and rs1570360 (P=0.03) genotypes were seen between CC cases and control groups; the distribution of the remaining SNPs was comparable between CC cases and control women. The association of rs699947 and rs1570360 with heightened CC risk with was seen in the heterozygous, and more so in the homozygous states. Haploview analysis revealed high LD between rs699947, rs833061, rs1570360, rs2010963, rs25648, rs833068 and rs833070 but weak or no LD between rs3025039 and the other SNPs. Seven-locus (rs699947/rs833061/rs1570360/rs2010963/rs25648/rs833068/ rs833070) haploview analysis identified only CTGCCAG haplotype to be positively associated with CC [P=0.022; OR(95% CI)=1.74 (1.08-2.79)]. CONCLUSION Specific VEGF variants (rs699947, rs1570360) and haplotype (CTGCCAG) may contribute to the development of CC among Tunisian women.

Involvement of Toll-like receptors in cervical cancer susceptibility among Tunisian women

Previous studies underscored the importance of genetic factors in the pathogenesis of certain cancers, including cervical cancer. Epidemiological evidence supports an association between specific polymorphisms of Toll-like receptors (TLR) with several human pathological states, including cervical cancer. The aim of this study was to investigate the link between specific gene variants in TLR2 (-196 to -174 del), TLR3 (c.1377 C>T), TLR4 (Asp299Gly), and TLR9 (2848 G>A) and susceptibility to cervical cancer in Tunisian women. Study subjects comprised 122 women with histopathologically-confirmed cervical cancer, and 260 unrelated age- and ethnically-matched healthy females, who served as controls. TLR genotyping was done using PCR-restriction fragment length polymorphism. The C/C genotype of TLR3 (c.1377 C>T) is associated with cervical cancer susceptibility (OR: 1.71, CI: 1.08-2.70). For TLR4 (Asp299Gly), the Asp/Asp genotype and the Asp allele were associated with higher risk of developing cervical cancer (OR: 4.95, CI: 1.97-13.22) and (OR: 5.17, CI: 2.11-13.50) respectively. We demonstrated no association between the TLR2 (-196 to -174 del) and the TLR 9 (2848 G>A) polymorphisms and the susceptibility of cervical cancer among Tunisian women. However, the C/C genotype for the TLR3 (c.1377 C>T) polymorphism and the Asp/Asp genotype and the Asp allele for (Asp299Gly) TLR4 polymorphism were found to be associated with a higher risk of cervical cancer.

IL-10 gene promoter and intron polymorphisms as genetic biomarkers of cervical cancer susceptibility among Tunisians

OBJECTIVE We investigated the association between polymorphisms in the promoter and intron regions of the interleukin-10 (IL-10) gene with the risk of cervical cancer (CC) in Tunisian patients and control women. METHODS Study subjects comprised 86 CC cases and 126 control women. Genotyping of IL-10 intron (rs3024491, rs3024490) and promoter (rs1800872, rs1800871, rs1800896) variants was done by real-time PCR, with defined clusters. RESULTS The minor allele frequencies of the five tested IL-10 SNPs were not significantly different between cervical cancer cases and control women. However, significantly higher frequencies of homozygous minor allele-carriers in cases was seen for rs3024490 (P=0.023), rs1800872 (P=0.037), and rs1800871 (P=0.028). IL-10 serum levels were significantly reduced in rs3024490 T/T vs. G/G genotype carriers, and in rs1800871 T/T than C/C genotype carriers. While carriage of rs1800872 and rs3024491 minor allele was associated with reduced IL-10 secretion, this was not statistically significant. Haploview analysis demonstrated high linkage disequilibrium (LD) among the IL10 SNPs studied, and only seven haplotypes were common, capturing 98.8% of the total possible haplotypes. Reduced frequency of haplotypes GTCCA (P<0.001) and TGATG (P<0.001) was seen in cervical cancer cases than in control women, thus conferring disease protection nature to these haplotype. This association remained significant for GTCCA (Pc=0.006) and TGATG (P=0.045) after correcting for multiple comparisons. CONCLUSION Specific IL-10 variants (rs3024490, rs1800872, and rs1800871) and haplotype (GTCCA and TGATG) may contribute to the development of cervical cancer among Tunisian women.

RETRACTED ARTICLE: Impact of Toll-Like Receptors 2/3/4/9, IL-1-α/β and TNF-α Polymorphisms in Cervical Cancer Susceptibility in Tunisia

– There are substantial parts in the article that were previously published in the article: “Involvement of Toll-like receptors in cervical cancer susceptibility among Tunisian women” by Sabrina Zidi, Hasibe Verdi, Yaprak YilmazYalcin, A.C. Yazici, Ezzedine Gazouani, Amel Mezlini, Fatma-Belgin Atac, Besma Yacoubi-Loueslati, Bulletin du Cancer, 2014; 101: E31-E35, DOI: 10.1684/bdc.2014. 2037. Although the article published in Pathology and Oncology Research uses a larger control group the two papers have very similar content, addressing the same problem with the same methodology and the differences in the articles were considered too minor. – In addition, this article was submitted to Pathology and Oncology Research without the knowledge or consent of all the authors.

TLR2 (-196 to -174 Ins/Del) and TLR3 (1377C>T) as biomarkers for nasopharyngeal cancer in Tunisia

Background/aim: We evaluated the association of TLR2 (-196 to -174 Ins/Del) and TLR3 (1377 C>T) as potential risk factors for nasopharyngeal carcinoma (NPC) in Tunisians. Material and methods: The study subjects comprised 137 NPC patients and 164 cancer-free control subjects. TLR2 genotyping was done by PCR and TLR3 genotyping was performed by PCR-RFLP. Results: Minor allele frequency (MAF) and genotypes of TLR3 (1377 C>T) were comparable between NPC patients and controls. Significantly higher MAF and TLR2-containing Del allele genotypes of TLR2 (-196 to -174 Ins/Del) were seen in NPC patients compared to controls [OR (95% CI) = 2.10 (1.43-3.08), P < 0.001 and OR (95% CI) = 2.07 (1.27-3.37), P = 0.003]. In addition, higher increased NPC risk was associated with the TLR2-Del/Del genotype [OR (95% CI) = 2.74 (1.37-5.48), P = 0.004]. An increased frequency of the Del-T haplotype was seen in NPC cases compared to controls. Conclusion: Our results demonstrate an increased risk of NPC with the TLR2-Del/Del genotype and Del-T TLR2 and TLR3 haplotype, suggesting their potential use as biomarkers to evaluate NPC risk in Tunisians.

Common variants in IL-1RN, IL-1β and TNF-α and the risk of ovarian cancer: a case control study

Aim of the study Several studies implicated altered inflammatory response in the susceptibility to ovarian cancer, and polymorphisms in inflammatory cytokines were shown to play an important role in the development of malignancies, including ovarian cancer (OC). Here we investigated the relationship between polymorphisms in IL-1β (-511C>T), IL-1RN VNTR, TNF-α (-308G>A), and TNF RII (-322 VNTR) and OC risk in Tunisian women. Methods and results Study subjects comprised 62 OC patients and 126 healthy women. Genotyping was done from genomic DNA obtained from blood simple by PCR. Positive association between IL-1RN (-VNTR) A1 allele (p = 0.0069; OR = 2.04; 95% CI:1.17-3.58) and OC risk, while negative association was seen with the A3 allele (P = 0.0034; OR = 0.09; 95% CI: 0.00-0.64), suggesting a protective role by the A3 allele. For IL-1β (-511C>T), homozygous C/C genotype was associated with significantly increased risk of OC (p = 0.0002; OR = 4.14; 95% CI: 1.77-9.76), while heterozygote C/T genotype was linked with reduced risk of OC (p = 0.0033; OR = 0.40; 95% CI: 0.20-0.78). Furthermore, TNF-α -308A allele was significantly associated with heightened risk of OC (p = 0.016; OR = 1.70; 95% CI: 1.08-2.69), and homozygote G/G genotype was associated with decreased risk of OC (p = 0.0018; OR = 0.25; 95% CI: 0.09-0.66). In contrast, TNFRII (-322 VNTR) polymorphism was not associated with altered OC risk in the studied group. Conclusions The significant association between IL-1RN VNTR, IL1-β (-511), TNF-α (-308) and OC susceptibility in Tunisian women confirms a role for altered inflammatory response in ovarian cancer pathogenesis.

Interleukin-1 Receptor Antagonist VNTR Polymorphism and Ovarian Cancer Susceptibility in Tunisian Women

Several studies indicate that interleukin-1 receptor antagonist (IL-1ra) is an important regulator of host immunity and play a key role in cancers development. Some of these studies have shown a potential role of a variable number of tandem repeat (VNTR) of 86 bp polymorphism within IL-1ra gene (IL-1RN) in host immune response variability. We investigated what VNTR polymorphism involves in susceptibility to ovarian cancer in Tunisia with a case control study. VNTR polymorphism within IL-1RN gene is genotyped by a simple PCR and agarose gel electrophoresis in 257 healthy women and 55 women with ovarian cancer. Our results indicated that allele 1 is associated with an increased susceptibility to ovarian cancer development (p=0.009; OR: 1.95, 95% CI, 1.14-3.36) and in the histological grading in Tunisian women. However, allele 3 seems to play a protective role (p=0.018; OR: 1.95, 95% CI, 0, 00-0.73). There were no significant differences between IL-1ra polymorphism alleles and tumor stage (International Federation of Gynecology and Obstetrics) but the allele 1 is significantly associated with histological grading in Tunisian women. The allele 1 of the IL-1RN seems to play a role in histological grading and susceptibility to ovarian cancer but it’s not associated with disease progression. Nevertheless, the risk for developing ovarian cancer is decreased by the presence of allele 3.

Association of IL10-1082 and IFN-γ

Objective. The aim of this study was to investigate the role of IL10-1082 and IFN-γ+874 polymorphisms in susceptibility to cervical cancer among Tunisian women. Study Design. The IL10-1082 and IFN-γ+874 polymorphisms were analyzed by ARMS-PCR in 160 healthy women and 122 with cervical cancer. The search for associations between those polymorphisms and cervical cancer was based on the test or Fishers exact test. Results. The IFN-γ+874 polymorphism showed significant increased frequency of T allele in healthy controls compared with patients (OR = 0.71, 95% CI = 0.50–1.01, and ) and individuals with homozygote IFN-γ+874 T/T genotype were at lesser risk of cervical cancer (OR = 0.53, 95% CI = 0.31–0.92, and ). However, carriers of allele have higher risk for developing cervical cancer (OR = 1.88, 95% CI = 1.09–3.24, and ). At the polymorphic nucleotide in position 1082 of the IL10 promoter, no differences were found between patients and controls subjects. Conclusion. Our study shows that the T/T genotype polymorphism of IFN-γ+874 T>A is a protective factor for cervical cancer among Tunisian women.

Association of Combined Tobacco Smoking, Hormonal Contraceptive use and Status Matrimonial with Cervical Cancer Evolution in Tunisian Women

Status matrimonial, cigarette smoking and hormonal contraceptive (HC) use have been associated with cervical cancer (CC) establishment by influencing the CC carcinogenesis process. In the present study, we aim to confirm this correlation between these factors and the risk of CC occurrence among Tunisian population. To evaluate the role of matrimonial status, smoking and HC as cofactors of CC installation, we performed a random selection of 600 women from Salah Azeiz institute in Tunisia and a questionnaire was conducted by doctors for each patient. Logistic regression after adjustment for potential confounding factors, relative excess risk due to interaction (RERI) and synergy index (S) were used to evaluate the additive interaction. Subgroup analysis was conducted to examine whether the relative risks changed with CC stages. There were an excess risk among smoker patients and patient with HC use ( p  < 0.001) for CC installation. Women who are smokers have a 14 times greater risk of suffering from cervical cancer and approximately 24 times greater to develop an advanced form of CC malignancy. Having a history of using birth control pills increase CC occurrence and aggravation (OR~2). The matrimonial status seems an important factor for CC appearance (OR = 3.58 and 2.46) among CC Tunisian patient. However, no significant biological interaction from this three joint exposure was observed in the early FIGO stages but the risk increase in advanced FIGO stages. In our Tunisian cohort, oral contraception, smoking habit and matrimonial status are associated with an overall increased risk of CC development. Indeed, it may damage the local immunity system and may affect the disease severity in patient carriers of some genetic risk biomarkers. The balance of cancer risks may vary among Tunisian CC patient, depending on some environmental co-factors.