Bystanders or active players: the role of extra centrosomes as signaling hubs.

Centrosomes serve as microtubule-organizing organelles that function in spindle pole organization, cell cycle progression, and cilia formation. A non-canonical role of centrosomes that has gained traction in recent years is the ability to act as signal transduction centers. Centrosome amplification, which includes numerical and structural aberrations of centrosomes, is a candidate hallmark of cancer. The function of centrosomes as signaling centers in cancer cells with centrosome amplification is poorly understood. Establishing a model of how cancer cells utilize centrosomes as signaling platforms will help elucidate the role of extra centrosomes in cancer cell survival and tumorigenesis. Centrosomes act in a diverse array of cellular processes, including cell migration, cell cycle progression, and proteasomal degradation. Given that cancer cells with amplified centrosomes exhibit an increased number and larger area of these signaling platforms, extra centrosomes may be acting to promote tumor development by enhancing signaling kinetics in pathways that are essential for the formation and growth of cancer. In this review, we identify the processes centrosomes are involved in as signal transduction platforms and highlight ways in which cancer cells with centrosome amplification may be taking advantage of these mechanisms.