The present study was aimed to investigate the effect of Janus kinase 3 (JAK3) on the migration of breast cancer cells and the underlying mechanism. The expression of JAK3 in breast cancer MCF-7 cells was silenced by siRNA (siJAK3). The migration ability of MCF-7 cells was detected by scratch test. The activity of store-operated calcium channel (SOCC) was detected by fluorescence calcium imaging. The expression levels of Orai1 and STIM1, key molecules in the process of store-operated calcium entry (SOCE) were detected by Western blot and RT-PCR. The results showed that 2-APB, an inhibitor of SOCC, could inhibit the migration ability of MCF-7 cells. siJAK3 transfection significantly inhibited the migration ability of MCF-7 cells, decreased the activity of SOCC, and down-regulated mRNA and protein expression levels of Orai1 and Stim1. Over-expression of Orai1 or STIM1 in JAK3-silenced cells restored their migration ability. These results suggest that JAK3 facilitates the migration of breast cancer cells by SOCC.
Breast Neoplasms ; enzymology ; Calcium ; metabolism ; Calcium Channels ; metabolism ; Cell Movement ; physiology ; Gene Expression Regulation, Neoplastic ; Humans ; Janus Kinase 3 ; genetics ; metabolism ; MCF-7 Cells ; ORAI1 Protein ; genetics

Store-operated calcium (Ca2+) entry (SOCE) is the principal Ca2+ entry route in non-excitable cells, including cancer cells. We previously demonstrated that Orai1 and STIM1, the molecular components of SOCE, are involved in tumorigenesis of clear cell renal cell carcinoma (CCRCC). However, a clinical relevance of Orai1 and STIM1 expression in CCRCC has been ill-defined. Here, we investigated the expression of Orai1 and STIM1 in CCRCC, and compared their expression with clinico-pathological parameters of CCRCC and the patients' outcome. Immunohistochemical staining for Orai1 and STIM1 was performed on 126 formalin fixed paraffin embedded tissue of CCRCC and western blot analysis for Orai1 was performed on the available fresh tissue. The results were compared with generally well-established clinicopathologic prognostic factors in CCRCC and patient survival. Membrane protein Orai1 is expressed in the nuclei in CCRCC, whereas STIM1 shows the cytosolic expression pattern in immunohistochemical staining. Orai1 expression level is inversely correlated with CCRCC tumor grade, whereas STIM1 expression level is not associated with tumor grade. The higher Orai1 expression is significantly associated with lower Fuhrman nuclear grade, pathologic T stage, and TNM stage and with favorable prognosis. The expression level of STIM1 is not correlated with CCRCC grade and clinical outcomes. Orai1 expression in CCRCC is associated with tumor progression and with favorable prognostic factors. These results suggest that Orai1 is an attractive prognostic marker and therapeutic target for CCRCC.
Adolescent ; Adult ; Aged ; Blotting, Western ; Carcinoma, Renal Cell/*diagnosis/metabolism/*pathology ; Female ; *Gene Expression Regulation, Neoplastic ; Humans ; Immunohistochemistry ; Kidney Neoplasms/metabolism/*pathology ; Male ; Middle Aged ; Neoplasm Proteins/genetics/metabolism ; ORAI1 Protein/genetics/*metabolism ; Prognosis ; Retrospective Studies ; Stromal Interaction Molecule 1/genetics/metabolism ; Young Adult