RESUMO
Breast cancer resistance protein (BCRP), also known as ABCG2, is a member of the ATP-binding cassette (ABC) transporter superfamily, and is known to play important roles in cancer multidrug resistance. The BCRP promoter lacks a TATA-box and contains a CAAT-box, lots of AP1, AP2 sites and several putative Sp1 sites which are downstream of a putative CpG island. Several transcription factors, such as progesterone receptor (PR), estrogen receptor (ER), nuclear factor-κB (NF-κB), hypoxia-inducible factors (HIFs), nuclear factor erythroid 2-related factor 2 (Nrf2), aryl hydrocarbon receptor (AhR), peroxisome proliferator-activated receptors (PPARs) and Krüppel-like factor 5 (KLF5), have been recently shown to bind to their response elements in the promoter/enhancer to activate the transcription of BCRP. BCRP transcription can be influenced by proinflammatory cytokines, growth factors, and homeobox protein MSX2. Signaling pathways, such as Sonic hedgehog (Shh), Notch and RAR/RXR pathways, may also involve in the transcriptional regulation of BCRP. In addition, promoter methylation and histone acetylation are essential for the BCRP transcription, especially for the drug-induced BCRP expression. This paper reviews the recent research progresses in this field with an emphasis on the roles of transcription factors and epigenetics in the transcriptional regulation of BCRP.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/genética , Transcrição Gênica , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Proteínas de Neoplasias/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
To investigate the association between single nucleotide polymorphisms (SNPs) rs2970847(Thr394Thr) and rs8192678(Gly482Ser) of peroxisome proliferators activated receptor gamma coactivator-1(PPARGC1A)gene and type 2 diabetes in Chinese Han population in Hubei. The Thr394Thr and Gly482Ser polymorphisms of the PPARGC1A gene were genotyped in 307 controls and 344 type 2 diabetes patients. Single marker/haplotype association analyses and logistic re-gression analysis were performed. Significant differences in genotypic and allelic frequencies were observed between cases and controls for the Thr394Thr polymorphism (genotype, P=0.006; allele, Plt;0.001). The genotype AA of the Thr394Thr polymorphism and the haplotype Thr394(ACA)- Ser482 were significantly associated with type 2 diabetes. No differences in the genotypic and allelic frequencies between cases and controls were found for the Gly482Ser polymorphism. PPARGC1A is a susceptibility gene for type 2 diabetes in Chinese Han population in Hubei.
