The many faces of SRPK1

Serine-arginine protein kinase 1 (SRPK1) phosphorylates proteins involved in the regulation of several mRNA processing pathways including alternative splicing. SRPK1 has been recently reported to be over-expressed in multiple cancers including prostate, breast, lung and glioma. Several studies have shown that inhibition of SRPK1 has anti-tumoural effects and consequently SRPK1 has become a new candidate for targeted therapies. Interestingly, in terms of molecular mechanism, SRPK1 seems to act heterogeneously and has been reported to affect several processes in different cancers, for example angiogenesis in prostate and colon cancer, apoptosis in breast and colon cancer and migration in breast cancer. A recent report adds to this puzzle, showing that the main effect of overexpression of SRPK1 in non-small-cell lung carcinoma is to stimulate a stem cell-like phenotype. This pleiotropy might be related to preferential activation of different downstream signaling pathways by SRPK1 in various cancers.