Evaluation of single nucleotide polymorphisms in microRNAs (hsa-miR-196a2 rs11614913 C/T) from Brazilian women with breast cancer

Background: Emerging evidence has shown that miRNAs are involved in human carcinogenesis as tumor suppressors or oncogenes. Single nucleotide polymorphisms (SNPs) located in pre-miRNAs may affect the processing and therefore, influence the expression of mature miRNAs. Previous studies generated conflicting results when reporting association between the hsa-miR-196a2 rs11614913 common polymorphism and breast cancer.Methods: This study evaluated the hsa-miR-196a2 rs11614913 SNP in 388 breast cancer cases and 388 controls in Brazilian women. Polymorphism was determined by real-time PCR; control and experimental groups were compared through statistical analysis using the X-2 or Fisher's exact tests.Results: the analysis of the SNPs frequencies showed a significant difference between the groups (BC and CT) in regards to genotype distribution (chi(2): p = 0.024); the homozygous variant (CC) was more frequent in the CT than in the BC group (p = 0.009). the presence of the hsa-miR-196a2 rs11614913 C/T polymorphism was not associated with histological grades (p = 0.522), axillary lymph node positive status (p = 0.805), or clinical stage (p = 0.670) among the breast cancer patients.Conclusions: the results of this study indicated that the CC polymorphic genotype is associated with a decreased risk of BC and the presence of the T allele was significantly associated with an increased risk of BC.Univ Fed Ceara, Dept Gynecol & Obstet, BR-62022304 Sobral, Ceara, BrazilUniversidade Federal de São Paulo, Mol Gynecol Lab, Dept Gynecol, BR-04039032 São Paulo, BrazilCtr Univ Fundacao Santo Andre, Dept Biol, São Paulo, BrazilUniv S Florida, Reprod Biol Res Lab, Div Reprod Endocrinol & Infertil, Dept Obstet & Gynecol, Tampa, FL 33612 USAUniversidade Federal de São Paulo, Mol Gynecol Lab, Dept Gynecol, BR-04039032 São Paulo, BrazilWeb of Scienc

Genetic association study of angiotensin II receptor types 1(A168G) and 2 (T1247G and A5235G) polymorphisms in breast carcinoma among sample of population of brazilian women

Varios canceres tem sido associados aos polimorfismos do sistema reninaangiotensina (SRA). No nosso estudo, objetivamos avaliar uma possivel associacao entre os polimorfismos nos genes do receptor de Angiotensina II tipo 1 denominado de AGTR1 (A168G) e tipo 2 denominado de AGTR2 (T1247G e A5235G) ao carcinoma mamario. Foram genotipadas 444 mulheres no total (N=234 mulheres do grupo de estudo portadoras de cancer de mama; N= 210 mulheres saudaveis do grupo controle) para a analise da distribuicao genotipica. As participantes tinham entre 26 e 90 anos e nao houve diferenca nos resultados quanto as variaveis menopausa e raca. Foram obtidas as seguintes distribuicoes genotipicas (em %): AGTR1 (A168G) - AA, AG, GG = 63; 23; 14 (grupo de estudo) e 63; 17; 20 (grupo controle) respectivamente (p= 0,29); AGTR2 (T1247G) - TT, TG, GG = 84; 13; 03 (grupo de estudo) e 81; 18; 01 (grupo controle) respectivamente (p = 0,39); AGTR2 (A5235G) - AA, AG, GG = 21; 44; 35 (grupo de estudo) e 20; 27; 53 (grupo controle) respectivamente (p = 0,021*). As portadoras do genotipo AA/AG apresentaram risco de 2,1 vezes maior de desenvolver o cancer de mama em comparacao com as portadoras do GG [O.R.= 2,1 com 95% C.I. (1,19-3,69); p=0,0152*. O genotipo GG pareceu ser protetor contra o cancer de mama. Todos os polimorfismos avaliados estavam condicionados com associacao a variaveis clinicas estudadas, sendo que estes SNPs poderiam estar correlacionados com o prognostico. Alem disso, o estudo do polimorfismo do gene do receptor de Angiotensina II tipo 2 (AGTR2; A5235G) como potencial marcador genetico de risco de cancer de mama deveria ser considerado em populacao de mulheres brasileirasBV UNIFESP: Teses e dissertaçõe

Differential gene expression assessed by cDNA microarray analysis in breast cancer tissue under tamoxifen treatment

Our purpose was to identify tamoxifen (TAM) responsive genes after 30 days of TAM treatment in tumor tissues obtained from women with breast cancer using microarray expression analysis. In our study, we identified 12 candidates to be considered as tamoxifen-modulated genes. Among them, we selected two candidates the TEGT BI-1 (testis enhanced gene transcript Bax Inhibitor-1) and the CD63 gene in order to further confirm their differential expression under tamoxifen effects. We observed that both were down-regulated in tumor tissues of patients during TAM treatment. TEGT is able to inhibit the expression of Bax, which is known to promote apoptosis. On the other hand, CD63 encodes a cell membrane protein and it seems to be involved in mechanisms of platelet activation. cell adhesion and cell motility. We therefore hypothesize that TAM would be able to modulate tumor growth by down-regulating genes involved in mechanisms such as cell cycle control, tumor invasion and metastasis.Univ Fed Sao Paulo, Dept Gynecol, Mol Gynecol Lab, Paulista Sch Med, Sao Paulo, SP, BrazilLudwig Inst Canc Res, Sao Paulo Branch, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Gynecol, Mol Gynecol Lab, Paulista Sch Med, Sao Paulo, SP, BrazilWeb of Scienc