A novel heat shock protein 90 inhibitor potently targets adrenocortical carcinoma tumor suppression

Introduction: Adrenocortical carcinoma is an aggressive cancer with a poor prognosis. Long noncoding RNAs are differentially expressed in cancer patients and contribute to cellular homeostasis, survival, and metastasis. We hypothesize that our novel C-terminal Hsp90 inhibitor KU758 can effectively target adrenocortical carcinoma cells and favorably alter long noncoding RNA expression. Methods: Cell viability after KU758 treatment was measured in the adrenocortical carcinoma cell lines SW13, RL251, and NCI-H295R by MTS assay. Cellular mobility and metastatic potential after Hsp90 inhibition was measured through migration, invasion, and aggregate formation assays. β-catenin activity in NCI-H295R cells was determined by immunofluorescence and polymerase chain reaction. Long noncoding RNA expression was determined by polymerase chain reaction array after Hsp90 inhibition. Results: KU758 is selective for adrenocortical carcinoma cells with IC50 values of 0.6 to 2.4 μM. KU758 treatment can effectively reduce migration, invasion, and aggregate formation in NCI-H295R and SW13 cells. β-catenin activity is decreased after treatment with KU758. Treatment with KU758 is associated with overall statistically significant upregulation of long noncoding RNA expression, including the tumor suppressor GAS5, which is implicated in the β-catenin and mammalian target of rapamycin pathways in adrenocortical carcinoma. Conclusion: The novel C-terminal Hsp90 inhibitor KU758 is effective in the treatment of adrenocortical carcinoma cells and can significantly alter long noncoding RNA expression for tumor suppression.