sta-9090 and 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin

Heat shock protein 90 (Hsp90) is an ATP-dependent molecular chaperone that is involved in the folding, activation, and stabilization of numerous oncogenic proteins. It has become an attractive therapeutic target, especially for eradicating malignant cancers and overcoming chemotherapy resistance. The Hsp90 family in mammalian cells is composed of four major homologs: Hsp90α, Hsp90β, 94-kDa glucose-regulated protein (Grp94), and TNF receptor-associated protein 1 (Trap1). Hsp90α and Hsp90β are mainly localized in the cytoplasm, while Grp94 and Trap1 reside in the endoplasmic reticulum and the mitochondria, respectively. Additionally, some Hsp90 s are secreted from the cytoplasm, commonly called extracellular Hsp90. Interestingly, each Hsp90 isoform is localized in a particular organelle, possesses a unique biological function, and participates in various physiological and pathological processes. To inhibit the organelle-specific Hsp90 chaperone function, there have been significant efforts to accumulate Hsp90 inhibitors in particular cellular compartments. This review introduces current studies regarding the delivery of Hsp90 inhibitors to subcellular organelles, particularly to the extracellular matrix and the mitochondria, and discusses their biological insights and therapeutic implications.

Topics: Animals; Benzoquinones; HSP90 Heat-Shock Proteins; Humans; Lactams, Macrocyclic; Organelles; Triazoles

Pharmacological inhibition of Hsp90 shows great promise in breast cancer treatment. This is the first systematic review to synthesize all available data and to evaluate the efficacy and safety of Hsp90 inhibitors in breast cancer.. This study was performed in accordance with the PRISMA guidelines. Eligible articles were identified by a search of MEDLINE and ClinicalTrials.gov databases, using a predefined combination of the terms "breast", "cancer", "Hsp90", "inhibitors".. Overall, 19 articles (190 patients) were eligible. The greatest clinical activity has been observed on the field of HER2-positive metastatic breast cancer. However, accumulating data suggest that Hsp90 inhibitors may play a significant role in the treatment of triple negative and aromatase inhibitor-resistant breast cancer.. In the last decade, the development of Hsp90 inhibitors has moved forward rapidly; however, no phase III trials have been conducted and none agent has been approved for use in the clinical practice.

Topics: Adenine; Antineoplastic Agents; Benzamides; Benzoquinones; Biomarkers, Tumor; Female; Glycine; HSP70 Heat-Shock Proteins; HSP90 Heat-Shock Proteins; Humans; Indazoles; Isoxazoles; Lactams, Macrocyclic; Pyridines; Resorcinols; Triazoles; Triple Negative Breast Neoplasms

Heat shock protein 90 (HSP90) expression is upregulated in numerous types of cancer. However, its role as a candidate for molecular targeted therapy in oral squamous cell carcinoma (OSCC) cells is poorly understood. In the present study, a common upstream search was performed using molecular network analysis software for proteins with expression abnormalities that were found in a proteomic analysis of six OSCC cell lines. HSP90 was identified as a target protein. In clinical samples, high frequencies of HSP90‑high expression were detected via immunohistochemistry (26/58; 45%). Furthermore, the HSP90 expression status was associated with cervical lymph node metastasis (P=0.015). Furthermore, the potential of HSP90 as a candidate for molecular targeted therapy in OSCC cells was investigated using the HSP90 inhibitors 17‑dimethylaminoethylamino‑17‑demethoxygeldanamycin (17‑DMAG) and ganetespib. KON cells, which strongly express HSP90, were treated with the HSP90 inhibitors. The numbers of living cells in the 17‑DMAG and ganetespib‑treated groups were lower than those in the non‑treated group. The cells treated with the inhibitors demonstrated reduced cell viability and migration, and this was associated with markedly decreased levels of the HSP90 target proteins EGFR, phospho‑EGFR, phospho‑MEK and phospho‑MAPK in the treated groups compared with the non‑treated group. To the best of our knowledge, this was the first study to investigate the effects of 17‑DMAG and ganetespib on OSCC cells. The present results indicated the potential of HSP90 as a useful candidate for molecular targeted therapy in OSCC. However, additional studies with larger sample sizes are required to confirm these findings.

Topics: Adult; Aged; Aged, 80 and over; Animals; Benzoquinones; Cell Line, Tumor; Cell Proliferation; Chemotherapy, Adjuvant; Drug Screening Assays, Antitumor; Female; HSP90 Heat-Shock Proteins; Humans; Lactams, Macrocyclic; Male; Middle Aged; Molecular Targeted Therapy; Mouth Mucosa; Mouth Neoplasms; Prognosis; Squamous Cell Carcinoma of Head and Neck; Survival Rate; Triazoles

Alectinib is a new generation ALK inhibitor with activity against the gatekeeper L1196M mutation that showed remarkable activity in a phase I/II study with echinoderm microtubule associated protein-like 4 (EML4)--anaplastic lymphoma kinase (ALK) non-small cell lung cancer (NSCLC) patients. However, alectinib resistance may eventually develop. Here, we found that EGFR ligands and HGF, a ligand of the MET receptor, activate EGFR and MET, respectively, as alternative pathways, and thereby induce resistance to alectinib. Additionally, the heat shock protein 90 (Hsp90) inhibitor suppressed protein expression of ALK, MET, EGFR, and AKT, and thereby induced apoptosis in EML4-ALK NSCLC cells, even in the presence of EGFR ligands or HGF. These results suggest that Hsp90 inhibitors may overcome ligand-triggered resistance to new generation ALK inhibitors and may result in more successful treatment of NSCLC patients with EML4-ALK.

Topics: Benzoquinones; Blotting, Western; Carbazoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Hepatocyte Growth Factor; HSP90 Heat-Shock Proteins; Humans; Lactams, Macrocyclic; Ligands; Lung Neoplasms; Mutation; Oncogene Proteins, Fusion; Phosphorylation; Piperidines; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-met; Transforming Growth Factor alpha; Triazoles