Application of suspension array assay to detect marker genes expression of circulating tumor cells for early prediction of breast cancer metastasis

Objective To develop a suspension array assay to detect the expression of multiple genes in the circulating breast cancer cells simultaneously so as to identify the marker genes for human breast cancer metastasis.Methods Peripheral blood samples were obtained from 73 breast cancer patients, including 31 breast cancer metastasis patients,30 patients with benign breast diseases,and 40 healthy women,and peripheral blood mononuclear cells (PBMCs) were isolated.Total RNA was extracted and eDNA was synthesized.PCR was used to amplify 8 breast cancer-related genes:hMAM,HER2,CK19, SBEM,EPG2,hTERT,β-HGG,and B3OSD.Suspension array of the PCR products was developed and underwent Luminex~(TM) 100 laser Flow-type analysis to read the fluorescence signal.COX proportional hazard model was used to find the independent prognostic predictors of breast cancer metastasis.Results hMAM expression was detected in 57.5%,HER2 in 57.5%,CKI9 in 53.4%,SBEM in 52.1%,EPG2 in 31.5% ,hTERT in 26.1%,β-HCG in 21.9%,and B305D in 15.1% of the blood samples respectively. Compared with serum CA15-3 detection,the multigene detection has higher sensitivity (P0.05).The expression of SBEM-mRNA in the peripheral blood was correlated with the stage of breast cancer(P 0.05);and hMAM,SBEM,HER2,and ER could be considered as the independent prognostic predictors of breast cancer metastasis (all P0.05).Conclusion The suspension array assay thus developed is practical in diagnosis of the prognosis of breast cancer.The expression of hMAM,SBEM,and HER2 in peripheral blood can be considered as the independent prognostic predictors of breast cancer metastasis.