Interdependency and differential expression of ERK1 and ERK2 in breast and melanoma cell lines

Regulatory mechanism of ERK1 and ERK2, their mechanisms of action, and how they impact on development, growth, and homeostasis of different organisms have been given much emphasis for long. ERK1 and 2 though are isoforms of ERK mitogen-activated protein kinase but are coded by two different genes MAPK3 and MAPK1 respectively and show differential expressions and interdependency in different cancer cell lines. Our previous investigations substantially stated the effect of ERK1 and ERK2 on different extracellular molecules like MMPs and integrins, responsible for cell growth and differentiation. Here, we aim to study individual roles of ERK1 and ERK2 and their interdependency in progression and invasiveness in various cancer cell lines. Different cancer cell lines namely B16F10 (melanoma), MCF7, and MDAMB231 (breast cancer) for studying this particular question were used. Methodologies like gelatin zymography, immunoprecipitation, Western blotting, cell invasion assay, wound healing assay, siRNA transfection, and double transfection procedures were followed for our study. Our findings suggest compensation for ERK2 deficiency by pERK1, clear ERK2 predominance in MCF7 cell line, ERK1-ERK2 interdependency in MDAMB231 cells with regard to compensating each other, and significant role of both ERK1 and ERK2 in modulation of MMP9. If summarized, our results prove the contribution of ERK2 in compensating ERK1 loss and vice versa and an evident role of ERK1 in cancer cell invasiveness.