Hsp90aa1, also known as heat shock protein 90 alpha family class A member 1, encodes the stress-inducible isoform of the molecular chaperone Hsp90. It is involved in maintaining the stability of many client proteins, and participates in various signaling pathways such as PI3K/Akt/mTOR and JNK/P38. Hsp90aa1 plays a crucial role in processes like autophagy, cell survival, and apoptosis, with implications for numerous biological functions and disease states [2].

In osteosarcoma, knockdown of Hsp90AA1 restored the sensitivity of cells to chemotherapy both in vivo and in vitro, indicating its role in promoting drug resistance through an autophagy-related mechanism. In this context, Hsp90AA1 increased drug resistance by inducing autophagy and inhibiting apoptosis [1]. In cisplatin-induced acute kidney injury, when Hsp90AA1 was knocked down, the protective effect of paeoniflorin did not continue, suggesting its importance in the protective mechanism of paeoniflorin which acts by promoting Hsp90AA1-Akt protein-protein interactions [3].

In conclusion, Hsp90aa1 is essential for maintaining normal cellular functions related to autophagy, apoptosis, and protein stability. Its role in diseases such as osteosarcoma and cisplatin-induced acute kidney injury, as revealed by loss-of-function experiments, highlights its potential as a therapeutic target. Understanding Hsp90aa1 can provide new insights into disease mechanisms and possible treatment strategies.