CYP1A2*1C, CYP2E1*5B, and GSTM1 polymorphisms are predictors of risk and poor outcome in head and neck squamous cell carcinoma patients.
Head and neck squamous cell carcinoma (HNSCC) is associated with environmental factors, especially tobacco and alcohol consumption. Most of the carcinogens present in tobacco smoke are converted into DNA-reactive metabolites by cytochrome P450 (CYPs) enzymes and detoxification of these substances is performed by glutathione S-transferases (GSTs). It has been suggested that genetic alterations, such as polymorphisms, play an important role in tumorigenesis and HNSCC progression. The aim of this study was to investigate CYP1A1, CYP1A2, CYP2E1, GSTM1, and GSTT1 polymorphisms as risk factors in HNSCC and their association with clinicopathologic data. The patients comprised 153 individuals with HNSCC (cases) and 145 with no current or previous diagnosis of cancer (controls). Genotyping of the single nucleotide polymorphisms (SNPs) of the CYP1A1, CYP1A2, and CYP2E1 genes was performed by PCR-RFLP and the GSTM1 and GSTT1 copy number polymorphisms (CNPs) were analyzed by PCR-multiplex. As expected, a significant difference was detected for tobacco and alcohol consumption between cases and controls (P<0.001). It was observed that the CYP1A2*1D (OR=16.24) variant and GSTM1 null alleles (OR=0.02) confer increased risk of HNSCC development (P<0.001). In addition, head and neck cancer alcohol consumers were more frequently associated with the CYP2E1*5B variant allele than control alcohol users (P<0.0001, OR=190.6). The CYP1A2*1C polymorphism was associated with tumor recurrence (log-rank test, P=0.0161). The CYP2E1*5B and GSTM1 null alleles were significantly associated with advanced clinical stages (T3+T4; P=0.022 and P=0.028, respectively). Overall, the findings suggested that the genetic polymorphisms studied are predictors of risk and are also associated with tumor recurrence, since they are important for determining the parameters associated with tumor progression and poor outcomes in HNSCC.
Olivieri
Eloisa Helena Ribeiro
EH
Department of Genetics, Institute of Biosciences, São Paulo State University - UNESP, Botucatu, Brazil.
da Silva
Sabrina Daniela
SD
Mendonça
Fernando Fernandes
FF
Urata
Yuri Nagamine
YN
Vidal
Daniel Onofre
DO
Faria
Marcilia de Araujo Medrado
Mde A
Nishimoto
Inês Nobuko
IN
Rainho
Claudia Aparecida
CA
Kowalski
Luiz Paulo
LP
Rogatto
Silvia Regina
SR
D000428:Alcohol Drinking / Q000235:genetics; D001938:Brazil; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D016022:Case-Control Studies; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D019388:Cytochrome P-450 CYP1A2 / Q000235:genetics*; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics*; D056915:DNA Copy Number Variations; D005260:Female; D005982:Glutathione Transferase / Q000235:genetics*; D006258:Head and Neck Neoplasms / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D020641:Polymorphism, Single Nucleotide; D011379:Prognosis; D012307:Risk Factors; D012907:Smoking / Q000235:genetics
D019363:Cytochrome P-450 CYP1A1; D019388:Cytochrome P-450 CYP1A2; D019392:Cytochrome P-450 CYP2E1; D005982:Glutathione Transferase; C413545:glutathione S-transferase T1