HSP27: Isoforms

Staining of somites of a rat embryo at 11 days of gestation. Red is rhodamine-phalloidin labeled actin and green is Hsp27, using Anti-Hsp27 (clone: 8A7)
Hsp27 has been also named as Growth-related 25 kDa protein, Heat shock 25 kDa protein (Short name, HSP 25), Heat shock 27 kDa protein (Short name, HSP 27) and Hsp28 and more recently as HspB1 (Table 2).37,1

For instance, heat shock protein B1 (HSP27, UnitProt ID #P04792) is a component of the large and heterogeneous group of chaperone proteins, and its main functions are inhibition of apoptosis and prevention of aggregation of actin intermediate filament.

Intensive investigations have been done on a variety of Hsp27 isoforms and their relation to cancer progression and heterogenicity. Modified expression of Hsp27 has been described in several cancers including testis, breast, and ovarian cancer. Moreover, some studies on renal cell carcinoma (RCC) tissues and homologous normal kidney tissues have been investigated for Hsp27 and shown significant differences either in expression or in Hsp27 isoform numbers in RCC compared to normal kidney. The numerous isoforms observed in RCC might be originated by post-translational modifications such as phosphorylation and S-thiolation.