Expression of GRIM-19 and its target gene product STAT3 in human breast cancer / 中华内分泌外科杂志

ABSTRACT

Objective To evaluate gene associated with retinoid-interferon-induced mortality-19 (GRIM-19) expression levels and the correlation with its target gene product signal transducers and activator of transcription 3 (STAT3)in human breast cancer tissues and normal gland tissues,and to analyze their roles in the tumorigenesis of breast cancer.Methods The expression of GRIM-19 and STAT3 protein and mRNA in 40 cases of breast cancer tissues and 40 cases of normal gland tissues was detected by immunohistochemistry and Western blot.The correlation of the expression of GRIM-19 and STAT3 to various clinicopathologic characteristics of breast cancer were analyzed statistically.The mRNA expression and gene mutation of GRIM-19 in breast cancer cell line MCF-7 and 25 specimens of breast cancer and normal gland tissue were detected by reverse transcription-polymerase chain reaction(RT-PCR)and sequencing.Results The protein and mRNA expression of GRIM-19 was obviously lower in breast cancer than in normal gland tissues (P ＜ 0.05) while the protein and mRNA expression of STAT3 was obviously higher in breast cancer than in normal gland tissues(P ＜0.05).The expression of GRIM-19 and STAT3 was negatively correlated with each other(x2 =8.25,P ＜0.01).Breast cancer samples exhibited low level of GRIM-19 and moderate to high level of STAT3 expression.In contrast,the normal gland tissue was characterized by high level of GRIP-19 and low level of STAT3 expression.The protein expression of GRIM-19 was correlated with the histological grading and clinical stage of breast cancer(P ＜ 0.05).STAT3 was not correlated with clinicopathologic characteristics of breast cancer (P ＞ 0.05).No mutation of GRIM-19 gene was detected in breast cancer tissues,normal gland tissues or MCF-7 breastcancer cells.Conclusions The low expression of GRIM-19 and the high expression of STAT3 co-exist in breast cancer.Downregulation of GRIM-19 was closely correlated with increased histological grade,clinical stage and STAT3 in breast cancer.The potential role of GRIM-19 in breast cancer development may be through these correlations.