Expression of ZFX Spliced Variants in Breast Cancer

ZFX, a member of kruppel C2H2-type zinc-finger protein family, is a transcriptional regulator in human embryonic stem cells that plays an important role in self-renewal property. ZFX is widely expressed in pluripotent stem cells and is down regulated during differentiation of embryonic stem cells. ZFX has five different variants that encode three different protein isoforms. While several reports have determined the overexpression of ZFX in a variety of somatic cancers, the expression of ZFX spliced variants in cancer cells is not well understood.In this study, the expression of ZFX variants in a series of breast cancer tissues was investigated by using qPCR approach. Our results showed that the expression of ZFX-variant1 and ZFX-variant4 are much higher in tumor tissues compared to marginal ones. In contrast, the ZFX-variant5 is down-regulated in tumor tissues. While the ZFX-variant1 expression increased significantly in low-grade tumors, ZFX-variant4 and ZFX-variant5 are highly expressed in high-grade and lymphatic invasion ones. Also, our data showed that the expression of ZFX-variant1 is significantly increased in luminal A subtype of breast cancer, whereas the expression of ZFX-variant4 was elevated in triple negative subtype. Here, our data revealed a significant association between the HER2 status and the expression of ZFX spliced variants. Altogether, our findings suggest that the expression of ZFX spliced transcripts is various in different types of breast cancer and maybe contributed in their tumorigenesis process. Hence, ZFX spliced transcripts can be considered as a novel tumor marker with potential diagnostic, prognostic and therapeutic values.

Keywords:

Breast Cancer , Cancer Stem Cells , ZFX Spliced Variants.