Abstract P3-04-07: Loss of Expression of the 14-3-3 Sigma by CpG Island Methylation and Relations with Prognostic Factor in Breast Cancer

Abstract

Background: Expression of 14-3-3 σ is a tumor suppressor gene induced in response to DNA damage, and has been implicated in G2/M cell cycle arrest by p53. Hypermethylation of CpG islands located in the promoter regions of tumor suppressor genes is now firmly established as an important mechanism for gene inactivation. Objetive: To correlation methylation levels of promoter 14-3-3σ with association prognostic factors in breast cancer.Material and Methods:This is a prospective study we quantified methylation levels of promoter 14-3-3 σ gene in 107 women with breast cancer and 108 control subjects by Real Time QMS-PCR SYBR green and analyzed association with prognostics factor in breast cancer. Results: Median age was 58 years (32-88); 69% were postmenopausal women.Nodal involvement N0; 63%,N1;30%,N2;7%), tumor size (T1;58%,T2;35%,T3;4%,T4;4%) and grade G1; 20%,G2;37%,G3;30%). The methylation of 14-3-3σ were 60% of sporadic breast cancer patients and were 34% of normal breast (p=0.0047).The methylation of 14-3-3σ gene in serum was markedly related with T3-4 stage (P<0.05),nodal positive status (P<0.05) and poor outcome. With a median follow up 6 years we saw more probability of developing distance metastasis in patients with methylation 14-3-3σ (P>0.05).Conclusions:Hypermethylation of the 14-3-3σ a promoter is an early and frequent event in breast neoplastic transformation, leading to the suggestion that silencing of 14-3-3σ may be an important event in tumor progression and particularly in breast carcinogenesis.Therefore, it is possible that loss of σ expression contributes to malignant transformation by impairing the G2 cell cycle checkpoint function, thus allowing an accumulation of genetic defects. Perhaps in the detection of CpG methylation of 14-3-3σ may be used for diagnostic and prognostic purposes Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-04-07.