RESUMO
BACKGROUND: The Melanocortin 1 Receptor (MC1R) contributes to pigmentation, an important risk factor for developing melanoma. Evaluating SNPs in MC1R and association with race/ethnicity, skin type, and perceived cancer risk in a New Mexico (NM) population will elucidate the role of MC1R in a multicultural population. METHODS: We genotyped MC1R in 191 NMs attending a primary care clinic in Albuquerque. We obtained individuals' self-identified race/ethnicity, skin type, and perceived cancer risk. We defined genetic risk as carriage of any one or more of the nine most common SNPs in MC1R. RESULTS: We found that one MC1R SNP, R163Q (rs885479), was identified in 47.6% of self-identified Hispanics and 12.9% of non-Hispanic whites (NHW), making Hispanics at higher "genetic risk" (as defined by carrying one of the MC1R common variants). When we deleted R163Q from analyses, Hispanics were no longer at higher genetic risk (33.3%) compared with NHW (48.3%), consistent with melanoma rates, tanning ability, and lower perceived risk. Hispanics had a perceived risk significantly lower than NHW and a nonsignificant better tanning ability than NHW. CONCLUSIONS: The R163Q variant in MC1R may not be a risk factor for melanoma among NM Hispanics. This suggestion points to the need to carefully interpret genetic risk factors among specific populations. IMPACT: Genetic risk cannot be extrapolated from Northern European populations directly to non-European populations.
Assuntos
Receptor Tipo 1 de Melanocortina/genética , Variação Genética , Genótipo , Humanos , New MexicoRESUMO
OBJECTIVES: A cross-sectional epidemiological study explored genetic susceptibility to oral precancer and cancer in Puerto Rico (PR). MATERIALS AND METHODS: Three hundred three individuals with a benign oral condition, oral precancer (oral epithelial hyperplasia/hyperkeratosis, oral epithelial dysplasia), or oral squamous cell carcinoma (SCCA) were identified via PR pathology laboratories. A standardized, structured questionnaire obtained information on epidemiological variables; buccal cells were collected for genetic analysis. Genotyping was performed using Taqman® assays. Allelic frequencies of single nucleotide polymorphisms (SNPs) were evaluated in cytokine genes and genes influencing tumor metastasis. Risk estimates for a diagnosis of oral precancer or SCCA while having a variant allele were generated using logistic regression. Adjusted models controlled for age, gender, ancestry, education, smoking and alcohol consumption. RESULTS: Relative to persons with a benign oral lesion, individuals with homozygous recessive allelic variants of tumor necrosis factor (TNF-α) -238 A/G SNP had a reduced odds of having an oral precancer (ORadjustedâ=â0.15; 95% CI 0.03-0.70). The transforming growth factor beta-1 (TGFß-1 -509 C/T) polymorphism was inversely associated with having an oral SCCA among persons homozygous for the recessive variant (ORcrudeâ=â0.27; 95% CI 0.09-0.79). The matrix metalloproteinase gene (MMP-1) variant, rs5854, was associated with oral SCCA; participants with even one variant allele were more likely to have oral SCCA (ORadjustedâ=â2.62, 95% CI 1.05-6.53) compared to people with ancestral alleles. CONCLUSION: Our exploratory analyses suggest that genetic alterations in immune system genes and genes with metastatic potential are associated with oral precancer and SCCA risk in PR.