Association of matrix metalloproteinase-2 gene variants with diabetic nephropathy risk.

BACKGROUND: Diabetic nephropathy is a highly destructive microvascular complication of diabetes. Genetic predisposition is involved in the pathogenesis of diabetic nephropathy, with multiple allelic polymorphisms associated with the development and progression of the disease, thereby increasing the overall risk. To date, no study is available that shows the association of matrix metalloproteinase-2 (MMP-2) gene polymorphisms with diabetic nephropathy risk. Thus, we investigated the potential genetic influence of MMP-2 promoter variants in the development of diabetic nephropathy in type 2 diabetic patients. METHODS: In total, 726 type 2 diabetic patients and 310 healthy controls were included in the study and genotyped for MMP-2, -1306C/T, -790T/G, -1575G/T and -735C/T by real-time PCR. The analysis of the outcomes was performed assuming three genetic models. The threshold for statistical significance was set at 0.05. RESULTS: The results showed that the minor allele frequency of the -790T/G variant was significantly higher in patients with and without nephropathy compared to controls. Furthermore, the distribution analysis revealed a significant association of the -790T/G variant, in all genetic models, with increased risk of diabetic nephropathy that persisted after adjusting for key covariates. No significant associations between MMP-2, -1306C/T, -1575G/T, -735C/T and the risk of diabetic nephropathy were detected. Haplotype analysis identified two risk haplotypes GCGC and GTAC associated with diabetic nephropathy. CONCLUSIONS: The present study is the first to demonstrate the allelic and genotypic association of the MMP-2-790T/G variant and two haplotypes with an increased risk of diabetic nephropathy in a Tunisian population with type 2 diabetes.

Association of matrix metalloproteinase-2 gene polymorphisms with susceptibility to type 2 diabetes: A case control study.

AIMS: Genetic variations mediating MMP-2 expression may result in individual differences in susceptibility to particular diseases. Our aim was to investigate the possible association of certain MMP-2 gene variants with the susceptibility of type 2 diabetes (T2D) in a Tunisian population. SUBJECTS AND METHODS: A retrospective case-control study involving 310 normoglycemic control subjects and 791 T2D patients was conducted. Genotyping of MMP-2 variants was performed by real time PCR. RESULTS: Minor allele frequencies (MAF) of the rs243865 and the rs243866 MMP-2, were significantly different between T2D cases and controls. Setting homozygous wild-type genotype carrier as reference, a reduced risk of T2D was seen with the rs243865 and the rs243866 genotypes. Haploview analysis revealed limited linkage disequilibrium between the tested MMP-2 and variants, with most haplotypes (99.5%) captured by 7 MMP-2 haplotypes. Taking the GCCC haplotype as reference for MMP-2 (OR = 1.00), a reduced frequency of TTCC haplotypes (P = 0.04) and the GTCC haplotype (P = 3.5 ·â€¯10-5) was noted in T2D which indicates a protective nature of these two haplotypes for T2D development. CONCLUSION: To the best of our knowledge, the present study is the first to demonstrate a consistent association of the rs243865 and rs243866 genotype with a protection for T2D.

Contrasting association of Leptin receptor polymorphisms and haplotypes with polycystic ovary syndrome in Bahraini and Tunisian women: a case-control study.

BACKGROUND: The present study examined the contribution of ethnicity to the association of leptin receptor gene (LEPR) gene variants with polycystic ovary syndrome (PCOS) in Tunisian and Bahraini Arabic-speaking women. METHODS: Subjects consisted of 320 women with PCOS, and 446 eumenorrhic women from Tunisia, and 242 women with PCOS and 238 controls from Bahrain. Genotyping of (exonic) rs1137100 and rs1137101 and (intronic) rs2025804 LEPR variants was done by allelic exclusion. RESULTS: The minor allele frequencies (MAFs) of rs1137100 and rs1137101 were significantly different between PCOS cases and control women from Bahrain but not Tunisia, and LEPR rs1137101 was associated with increased PCOS susceptibility only in Bahraini subjects. Furthermore, rs1137100 was associated with decreased PCOS risk among Bahrainis under codominant and recessive models; rs1137100 was negatively associated with PCOS in Tunisians after controlling for testosterone. In addition, rs2025804 was associated with increased PCOS risk among Tunisian but not Bahraini women, after adjusting for key covariates. Negative correlation was seen between rs1137101 and triglycerides in Tunisians, while homeostasis model assessment of insulin resistance (HOMA-IR) and insulin correlated with rs2025804 and rs1137101 among Bahraini subjects, and rs1137101 correlated with estradiol and prolactin. Taking TAG haplotype as common, positive association of TAA and negative association of TGG haplotype with PCOS was seen among Bahraini women; no three-locus PCOS-associated haplotypes were found in Tunisians. CONCLUSIONS: The present study is the first to demonstrate the contribution of ethnicity to the association of LEPR gene variants with PCOS, thereby highlighting the significance of controlling for ethnicity in gene association investigations.

Identification of novel advanced glycation end products receptor gene variants associated with colorectal cancer in Tunisians: A case-control study.

A central role for advanced glycation end products (AGE) and their receptor (RAGE) in the pathogenesis of multiple cancer types, including colorectal cancer (CRC) was reported. We investigated the association between CRC and rs2853807, rs77170610, rs184003, rs1035798, rs2070600, rs1800684, rs1800624, and rs1800625 RAGE gene (AGER) polymorphic variants. Study subjects comprised 293 CRC patients [186 colon cancer (CC) and 107 rectal cancer (RC)] patients), and 264 age-, gender-, BMI-, and ethnicity-matched controls. Minor allele frequency (MAF) of rs77170610 and rs1800625 were significantly lower, while MAF of rs1035798 was significantly higher in CRC patients compared to control subjects, which was associated with reduced and increased risk of CRC, respectively; MAF of the remaining variants was comparable between CRC patients and controls. Significant difference in the distribution of rs2853807 and rs77170610 genotypes was seen between CRC patients and controls, with both variants associated with decreased risk of CRC. Comparison of the distribution of minor allele-carrying genotypes in CC and RC patient subgroups revealed lack of significant difference in the distribution of these genotypes between the patient subgroups. In view of the lack of LD between rs2853807 and rs77170610 with other variants, six-locus (rs184003, rs1035798, rs2070600, rs1800684, rs1800624, rs1800625) haplotypes were constructed. Haplotype analysis did not identify any specific 6-locus AGER haplotype associated with CRC. In conclusion, AGER gene rs2853807 and rs77170610 variants rs77170610 are associated with altered risk of CRC in Tunisians, but with no discrimination between CC and RC types.

Association of estrogen receptor gene variants (ESR1 and ESR2) with polycystic ovary syndrome in Tunisia.

SNV (single nucleotide variation) in estrogen receptor (ESR1 and ESR2) genes are susceptibility markers for complex diseases, such as cancer, metabolic disorders and women infertility. We explored six widely used SNVs in ESR1 (rs2234693, rs9340799, rs3798577, rs3020314) and ESR2 (rs1256049, rs4986938) in polycystic ovary syndrome (PCOS) in women from Tunisia (n = 254) compared to controls (n = 170). Genotyping was performed by RFLP-PCR or real-time PCR and analyzed in GoldenHelix statistical package. Logistic regression revealed association of rs2234693, rs3798577 and rs3020314 (ESR1) and rs1256049 (ESR2), the association of rs2234693 (C/T) being the strongest with P < 4.81 × 10-6, 2.88 × 10-5 after Bonferroni correction, OR 0.31, 95%CI (0.18-0.53)). Correlations were found with LH, LH/FSH or hyperandrogenism and even more significant with metabolic syndrome (rs9340799) and hyperglycemia (rs3798577). Among 14 haplotypes reconstructed in ESR1gene, four haplotypes (H1 to H4) were associated with PCOS the strongest being that of H1 (P < 0.002) supported by Bonferroni (P < 0.033) and permutation tests (P < 4 x10-4). In haplotype trend regression, concordant correlations were found with insulin resistance (P < 0.033) for H2 and with high blood pressure for H3 (P < 0.048). While these data revealed influential role on metabolic rather and hormonal features of PCOS, the association of rs2234693 was the strongest among all ethnic populations studied thus far giving a new insight on estrogen receptor gene variation in distant North African populations and their role in metabolic alteration of PCOS.

Interleukin-17A polymorphisms predict the response and development of tolerance to FOLFOX chemotherapy in colorectal cancer treatment.

Polymorphic variants in IL-17A gene were differentially associated with colorectal cancer (CRC) susceptibility but their link with response and toxicity to CRC treatment have not yet been evaluated. We investigated association between seven IL-17A variants with the response and toxicity to CRC treatment in 294 patients with CRC. IL-17A genotyping was done by real-time PCR. MAF of rs3748067 was significantly higher in CRC cases resistant to FOLFOX treatment (R+) than non resistant (R-). Significantly higher rs3804513 MAF was noted in R+ versus R- colon cancer (CC). Higher rs2275913 and rs10484879, and reduced rs3804513 MAF were seen in rectal cancer (RC) tolerant to FOLFOX (T+) compared to (T-) patients. Strong association of rs3819025, rs3804513, and rs7747909 was found with tolerance to RC treatment. rs3748067 was associated with FOLFOX tolerance in CC but not RC. Significant higher frequency of AGGCAGG and GAGCAGG haplotypes was seen among R + CC, thus assigning non-favorable nature to these haplotypes. Higher and lower frequencies of GAGTAAG and AGGCTGA haplotypes, respectively, were observed in T + RC, thereby assigning FOLFOX-tolerant and non-tolerant nature to these haplotypes. The obtained results suggest that IL-17A variants and haplotypes may be a target for future management of CRC treatment.

Circulating leptin concentration, LEP gene variants and haplotypes, and polycystic ovary syndrome in Bahraini and Tunisian Arab women.

BACKGROUND AND AIM: Epidemiological studies suggested that ethnic/racial background influences the associations of altered leptin secretion and leptin gene (LEP) polymorphisms with polycystic ovary syndrome (PCOS). We investigated the association between LEP variants and plasma leptin levels with PCOS in Tunisian and Bahraini Arab women. SUBJECTS AND METHODS: Retrospective case-control study, involving 255 PCOS cases and 253 control subjects from Bahrain, and 320 women PCOS cases and 447 controls from Tunisia. LEP genotyping was done by allele exclusion on real-time PCR. RESULTS: Minor allele frequencies of rs10487506, rs7799039, rs2167270, rs12706832, and rs10954173 LEP variants were not significantly different between PCOS cases and control women among Bahraini and Tunisians, even before applying the Bonferroni correction. Similarly, the genotype distribution of the tested LEP variants was comparable between women with PCOS and control women among Bahraini and Tunisian subjects. None of the tested LEP variants was linked with altered leptin serum concentrations. However, five-locus haplotype analysis identified GGGGG and GAGGG haplotypes to be positively, and haplotype AAGGG to be negatively associated with PCOS in Bahraini women, after adjusting for HOMA-IR. No LEP haplotype associated with PCOS was identified in Tunisians. CONCLUSION: This is the first study to document differential contribution of LEP gene variants with PCOS according to ethnic/racial background of study subjects, highlighting the need for controlling for ethnicity in genetic association studies.

Association of interleukin-17A polymorphisms with the risk of colorectal cancer: A case-control study.

BACKGROUND: Interleukin (IL)-17A is proinflammatory cytokine produced by Th17 cells, which play key, but sometimes inconsistent role in autoimmunity and cancer. Polymorphic variants in IL-17A gene were differentially associated with susceptibility to cancer, including colorectal cancer (CRC). AIM: We investigated the association between six IL-17A gene variants (rs3819024, rs2275913, rs3819025, rs10484879, rs7747909, and rs3748067) with CRC susceptibility in Tunisians. SUBJECTS AND METHODS: Retrospective case-control study. Study subjects comprised 293 patients with CRC, and 268 age-, gender-, and BMI-matched healthy controls. IL-17A genotyping was done by real-time PCR, with defined clusters. RESULTS: Of the seven tested IL-17A tag-SNPs, minor allele frequency (MAF) of rs10484879 was significantly higher in CRC patients than control subjects. Heterozygous rs10484879 [OR (95% CI) = 2.63 (1.64-4.21)] was associated with higher risk, while carriage of heterozygous rs3748067 genotype was associated with reduced risk of CRC [OR (95% CI) = 0.56 (0.37-0.84)], respectively. Carriage of rs10484879 minor allele correlated with positive family history of CRC and other cancers (P = 0.002), CRC staging (P = 0.044), CRC treatment (P = 0.038), and with chemo body reaction (P = 0.001). Of the 7 IL-17A variants, 4 were in linkage disequilibrium, hence allowing for construction of 4-locus haplotypes. Varied linkage disequilibrium (LD) was noted between the even tested IL-17A variants, and further analysis was limited to only 4-locus (rs3819024-rs2275913- rs10484879-rs7747909). Haploview analysis identified the 4-locus IL-17A haplotypes AGTG (P < 0.011), and GATG (P = 0.036) to be positively associated with CRC, after controlling key covariates. CONCLUSION: IL-17A rs10484879 SNP, and IL-17A haplotypes AGGTG and GAGTG constitute independent factors of CRC susceptibility. We propose that IL-17A may be a target for future CRC immunotherapy.

Differential association of DENND1A genetic variants with polycystic ovary syndrome in Tunisian but not Bahraini Arab women.

BACKGROUND AND AIM: Polycystic ovary syndrome (PCOS) is a common endocrine disorder, and results from interaction between modifiable and non-modifiable factors, including genetic predisposition. Previous genome-wide association studies and meta-analysis identified DENND1A as PCOS susceptibility locus in some, but not all populations. We investigated whether the association of DENND1A gene variants with PCOS was similar between Tunisian and Bahraini Arab women. SUBJECTS AND METHODS: This was retrospective case-control study. Study subjects comprised 320 women with PCOS, and 446 age-and ethnically-matched control women. Genotyping of DENND1A rs10818854, rs2479106, and rs10986105 variants was done by real-time PCR. RESULTS: Minor allele frequency of rs10818854 and rs10986105 DENND1A variants were significantly higher among women with PCOS. Setting homozygous wild-type genotype carrier as reference, rs10818854 and rs10986105 were associated with increased risk of PCOS, which persisted after controlling for key covariates, while reduced PCOS risk was seen with only rs2479106 under the additive model. This assigned PCOS susceptibility and protective nature to these genotypes, respectively. Both rs10818854 and rs10986105 were positively associated with HOMA-IR and AMH in women with PCOS. Haploview analysis revealed limited linkage disequilibrium between the tested DENND1A variants. Extensive diversity in haplotypes assignment was seen, with most haplotypes (99.5%) captured by 5 haplotypes. Taking GAT haplotype as reference, AAG, and GAG haplotypes were positively, while GAT haplotype was negatively associated with PCOS. CONCLUSION: The association of DENND1A rs10818854 and rs10986105 variants with PCOS in Tunisian but not Bahraini women confirms the dependence of this association on the ethnic/racial origin of study subjects.