Genes of detoxification are important modulators of hereditary medullary thyroid carcinoma risk.

Clinical endocrinology

PubMedID: 23278115

Barbieri RB, Bufalo NE, Cunha LL, Assumpção LV, Maciel RM, Cerutti JM, WARD LS. Genes of detoxification are important modulators of hereditary medullary thyroid carcinoma risk. Clin Endocrinol (Oxf). 2013;79(2):288-93.
CONTEXT
Different inherited profiles of genes involved in cellular mechanisms of activation and detoxification of carcinogenic products can provide specific protection or determine the risk for cancer. Low-penetrance polymorphic genes related to the biotransformation of environmental toxins have been associated with susceptibility to and the phenotype of, human tumours.

OBJECTIVE
To investigate the role of germline inheritance of polymorphisms in CYP1A2*F, CYP1A1 m1, GSTP1, NAT2 and TP53 genes in hereditary medullary thyroid carcinoma (HMTC) patients.

DESIGN
This study was developed in University of Campinas (Unicamp).

PATIENTS
We studied 132 patients with HMTC, 88 first-degree relatives of HMTC patients and 575 control individuals.

MEASUREMENTS
All patients with MTC and their relatives were sequenced for the RET gene and five genes were genotyped using TaqMan(®) system.

RESULTS
We observed that the inheritance of CYP1A2*F (OR = 2·10; 95% CI = 1·11-3·97; P = 0·022), GSTP1 (OR = 4·41; 95% CI = 2·47-7·88; P < 0·001) and NAT2 (OR = 2·54; 95% CI = 1·16-5·58; P = 0·020) variants increased the risk for HMTC. In addition, multiple regression analysis showed that the inheritance of GSTP1 polymorphisms was associated with the diagnosis in older patients (B = 8·0229; 95% IC = ± 5·5735; P = 0·0054). Concerning the group of HTMC relatives, CYP1A2*F (OR = 2:40; 95% CI = 1·19-4·86; P = 0·015), CYP1A1 m1 (OR = 2·79; 95% CI = 1:04-7·51; P = 0·042), GSTP1 (OR = 2·86; 95% IC = 1·53-5·32; P < 0·001) and NAT2 (OR = 2·25; 95% IC = 1·20-4·22; P = 0·012) were associated with HMTC risk.

CONCLUSIONS
We have demonstrated that the inheritance of specific genes determining the individual response to environmental toxins may contribute to the risk and phenotypic variability that exists in patients with HMTC. Moreover, we identified a group at risk in relatives of HMTC patients.