Abstract 1294
Background
The epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) osimertinib improves therapy for non-small cell lung cancer (NSCLC) patients who possess EGR mutations. However, invariable acquired resistance appears due to several molecular mechanisms. Hsp90 protein clients are involved in these processes.
Methods
Cell viability and colony formation assays were performed in PC9, H1975 and PC9-derived osimertinib-resistant NSCLC cell lines tested with osimertinib plus hsp90 inhibitors, luminespib or ganetespib. To analyze the mechanism of action of these compounds and its combination, western blot analysis was carried out to study the protein expression and activation.
Results
In our laboratory five osimertinib-resistant cell lines were generated from PC9 NSCLC cell line and overexpression or activation of several proteins, such as, AXL, Yap, bcl2, Akt, Stat3 and IGF-1R were detected. Hsp90 inhibitors, Ganetespib and Luminespib, inhibited cell viability and colony formation in H1975, PC9 and PC9-derived osimertinib-resistant cell lines, and the combination of these inhibitors with osimertinib achieved enhanced cell viability reduction. Luminespib downregulated the expression of several proteins involved in osimertinib-resistance and the combination of this compound plus osimertinib caused an important decrease of expression in several of these proteins, such as, Stat3, Yap, Akt, EGFR and Met. In addition, osimertinib activated the phosphorylation of several membrane receptors and downstream molecules, such as, Met, Yap, Stat3, Akt and Src, and its activation was partially inhibited by Luminespib.
Conclusions
We conclude that hsp90 inhibitors and osimertinib exhibit good efficiency in inhibiting cell viability and colony formation, while at the same time, inhibiting expression and activation of proteins involved in osimertinib-resistance. Our preclinical study shows that the combination of hsp90 inhibitors and osimertinib may represent an effective strategy for NSCLC patients with resistance to osimertinib treatment.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Pangaea Oncology.
Funding
Pangaea Oncology.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
6171 - Molecular EGFR/PD-L1 profile of glioblastoma: Hints for therapeutic strategies
Presenter: Wojciech Szopa
Session: Poster Display session 1
Resources:
Abstract
4418 - Role of Intraoperative MRI (iMRI) in neurosurgery, potential imaging tool for maximizing gross total resection (GTR) rate of CNS tumours.
Presenter: Shweta Wadhwa
Session: Poster Display session 1
Resources:
Abstract
4791 - Tumor related impairments of neurocognitive functions in patients with brain metastases
Presenter: Lei Wen
Session: Poster Display session 1
Resources:
Abstract
5372 - Is radiation therapy influencing Alzheimer’s in Brain and Head and Neck Cancers?
Presenter: Anas Saad
Session: Poster Display session 1
Resources:
Abstract
2329 - Mature Treatment Results of 120 Cases of Acoustic Neuroma Treated with Cyberknife at a single institution.
Presenter: Shawn Malone
Session: Poster Display session 1
Resources:
Abstract
3207 - A phase II/III trial of high-dose, intermittent sunitinib in patients with recurrent glioblastoma: the STELLAR study
Presenter: Cyrillo Brahm
Session: Poster Display session 1
Resources:
Abstract
3589 - CNS penetration and Preliminary Efficacy of Sacutizumab Govitecan in Breast Brain Metastasis and Glioblastoma: A Surgical Study
Presenter: Andrew Brenner
Session: Poster Display session 1
Resources:
Abstract
1969 - Wedge resection with omission of lymph node dissection as an optional treatment strategy in octogenarians or older with early stage non-small cell lung cancers
Presenter: Takahiro Mimae
Session: Poster Display session 1
Resources:
Abstract
5116 - Characterization of lung tumorspheres reveals cancer stem-like cells potential targets and prognostic markers in non-small cell lung cancer
Presenter: Alejandro Herreros Pomares
Session: Poster Display session 1
Resources:
Abstract
5823 - Pulmonary tumor-draining vein exosomal lincRNA-p21 levels impacts non-small cell lung cancer prognosis
Presenter: Joan Castellano
Session: Poster Display session 1
Resources:
Abstract