Expression of Protein Kinase C α and the MZF-1 and Elk-1 Transcription Factors in Human Breast Cancer Cells

Recently, our research into hepatocellular carcinoma (HCC) has shown that the transcription factors Myeloid Zinc Finger-1 (MZF-1) and Ets-like-protein 1 (Elk-1) are related to protein kinase C alpha (PKC alpha) expression. The purpose of this study was to determine the correlation of the expression of PKC alpha with the expressions of Elk-1 and MZF-1 in various differentiated breast cancer cell lines: MDA-MB-231, Hs57BT, SKBR3, MDA-MB-468 and MCF-7. The malignant potential in the five lines of breast cancer cells was examined by using a cell proliferation/migration/invasion assay and the protein and mRNA levels of PKC alpha, Elk-1 and MZF-1 were examined by Western blot and RT-PCR analysis, respectively. The results showed that there were obvious signs of migration and invasion of cells in MDAMB-231 and Hs57BT cells, little signs of cell migration and invasion in MDA-MB-468 cells, and no sign in SKBR3 and MCF-7 cells. Moreover, the highest expression levels of PKC alpha, Elk-1 and MZF-1 were also observed in MDA-MB-231 and Hs57BT cells when compared to the other breast cancer cell lines. These findings confirm that elevated expression of PKC alpha in breast cancer cells may be correlated with the potential of cell migration and invasion, and suggest an association between the expression of PKC alpha and the expression of the transcription factors Elk-1 and MZF-1.