Polymorphisms of GSTM1 and GSTT1 genes in breast cancer susceptibility: a case-control study

Abstract

Breast cancer patients presented higher frequency of homozygous deletion of the GSTM1 gene compared with the control group.

Association of the GSTM1 null polymorphism with breast cancer in a Mexican population

“…The genetic regulation of phase II metabolism and its relation to carcinogenesis has been the focus of many investigations. GSTs are a family of important enzymes involved in phase II metabolism and the detoxification of a wide variety of known and suspected carcinogens, including potential mammary carcinogens (Possuelo et al, 2013;Wan et al, 2014). The null GSTM1 polymorphism expresses no GSTM1 enzymatic activity and might present a decreased metabolism of carcinogens, which might accelerate neoplastic processes (Possuelo et al, 2013;Sohail et al, 2013;Wan et al, 2014).…”

“…Wan et al (2014), in a meta-analysis study, demonstrated an association of the null GSTM1 genotype with BC in a Chinese population. Possuelo et al (2013) found an association between the GSTM1 null genotype with BC in a Brazilian population. Sohail et al (2013) similarly demonstrated an increased susceptibility to BC in null GSTM1 members of a Pakistani population.…”

“…This leads to a lack of expression of the GST mu enzymes that results in decreased antioxidant activity in the cell (Duggan et al, 2013), high accumulation of reactive oxygen species (ROS), and consequently higher susceptibility to carcinogenic events due to DNA damage (McLellan et al, 1997;Wang et al, 2010). It has been suggested that the null GSTM1 is associated with an increased risk of developing some types of cancers including BC (McLellan et al, 1997;de Aguiar et al, 2012;Duggan et al, 2013;Possuelo et al, 2013;Wan et al, 2014). Wan et al (2014), in a meta-analysis study, demonstrated an association of the null GSTM1 genotype with BC in a Chinese population.…”

Polimorfismo nulo do gene GSTM1 na suscetibilidade do câncer de mama[/title]: [subtitle]evidências baseadas em meta-análise

“…A glutationa S-transferase (GST) é uma enzima intracelular, cuja ação impede o efeito danoso de toxinas endógenas e exóge-nas (xenobióticos) sobre as células e as moléculas de DNA. Por estarem diretamente relacionadas com o metabolismo de agentes carcinogênicos e poluentes ambientais, a ausência de isoenzimas específicas de GST estão comumente relacionadas ao aumento da suscetibilidade a diversos tipos de câncer 5,6 . O gene GSTM1, localizado no cromossomo 1p13.1, é alvo de polimorfismo de deleção de exposição.…”

“…Este resultado indica que a probabilidade dos indivíduos não apresentarem o polimorfismo nulo do gene GSTM1 é maior em indivíduos que não apresentam câncer de mama do que em pacientes com esta neoplasia. Contudo, Possuelo et al 6 relataram que, em seus estudos, mulheres com uma máxima proporção de gene GSTM1 nulo tiveram câncer de mama (OR: 0,400) (Figura 1).…”