Cytoskeleton targeting value in prostate cancer treatment

Prostate cancer is a disease that affects hundreds of thousands of men in the United States each year. In the early stages of advanced prostate cancer, the disease can be suppressed by androgen deprivation therapy (ADT). Eventually, however, most patients experience resistance to androgen deprivation, and their treatment transitions to alternative targeting of the androgen axis with abiraterone and enzalutamide, as well as taxane-based chemotherapy. Development of advanced castration-resistant prostate cancer (CRPC) is a consequence of lack of an apoptotic response by the tumor cells to treatment. Understanding the mechanisms contributing to prostate tumor therapeutic resistance and progression to metastasis requires dissection of the signaling mechanisms navigating tumor invasion and metastasis as mediated by cell-matrix interactions engaging components of the extracellular matrix (ECM), to form adhesion complexes. For a tumor call to metastasize from the primary tumor, it requires disruption of cell-cell interactions from the surrounding cells, as well as detachment from the ECM and resistance to anoikis (apoptosis upon cell detachment from ECM). Attachment, movement and invasion of cancer cells are functionally facilitated by the actin cytoskeleton and tubulin as the structural component of microtubules. Transforming growth factor (TGF)-β has tumor-inhibitory activity in the early stages of tumorigenesis, but it promotes tumor invasive characteristics in metastatic disease. Recent evidence implicates active (dephosphorylated) cofilin, an F-actin severing protein required for cytoskeleton reorganization, as an important contributor to switching TGF-β characteristics from a growth suppressor to a promoter of prostate cancer invasion and metastasis. Cancer cells eventually lose the ability to adhere to adjacent neighboring cells as well as ECM proteins, and via epithelial-mesenchymal transition (EMT), acquire invasive and metastatic characteristics. Microtubule-targeting chemotherapeutic agents, taxanes, are used in combination with antiandrogen strategies to increase the survival rate in patients with CRPC. This review addresses the development of therapeutic platform for targeting the integrity of actin cytoskeleton to impair prostate cancer progression.