αB-crystallin as a promising target in pathological conditions - A review

Abstract

Introduction and objective: αB-crystallin belongs to the ubiquitous family of small heat-shock proteins. It was discovered as a physiological protein of the eye lens, maintaining its liquid-like property. Furthermore, αB-crystallin was proved to playa bipolar role in both physiological and pathophysiological conditions. This review discusses current knowledge about the biology and genetics of αB-crystallin, and summarizes recent advances in understanding its role in ophthalmic and neurological disorders, as well as breast cancer, renal cancer and other malignancies.

State of knowledge: α-crystallins are established as important elements of the protein quality control network, and consequently their defects are related to multiple human diseases. New studies highlight αB-crystallin's involvement in proliferative diabetic retinopathy angiogenesis and point out its therapeutic potential in age-related macular degeneration. αB-crystallin is thought to be associated with the disease-causing protein aggregates, leading to its connection with such neurological disturbances as anaplastic astrocytoma, Parkinson disease, aging deficits in the peripheral nervous system and multiple sclerosis. In breast cancer, it was proven to be a marker of aggressive behaviur and cerebral metastases. Strong expression of αB-crystallin promoted growth and migration of clear cell renal cell carcinoma cells and was correlated with lower overall survival rate. Considering other malignancies, its various roles were established in colorectal and gastric cancers, head and neck squamous cell carcinomas and osteosarcomas.

Conclusions: Further studies concerning αB-crystallin seem to be enormously promising, as they might improve our understanding of common human pathologies as well as contemporary diagnostics and treatment.

Keywords: breast cancer; renal cell carcinoma; small heat-shock proteins; αB-crystallin.