Abstract 2894: Neratinib effects significant changes in human brain endothelial cells, demonstrating that it may have a therapeutic use in cancers with brain metastasis

Abstract

Abstract Background: Brain metastases constitute a significant part of intracranial tumors and the majority of brain metastases originate from lung, breast cancers and malignant melanoma. Breast cancer patients who develop brain metastases tend to have poor prognosis with short overall survival. Moreover, human epidermal growth factor receptor 2 (HER2)-positive breast cancer have an increased propensity for brain metastases. Currently, patients with brain metastases have limited therapeutic options. The failure of many cancer therapeutics for the treatment of brain metastasis has been partly attributed to an intact blood-brain barrier (BBB) tightly controlled by endothelial tight junctions (TJ). Neratinib is an orally available tyrosine kinase inhibitor that irreversibly binds to and inhibits EGFR, HER2 and HER4 receptor tyrosine kinases. This study aimed to examine the effect of neratinib on protein expression and phosphorylation status in human brain endothelial cells. Methods: Changes in protein phosphorylation in human brain (TY09 and CMEC D3) and venous endothelial cells (HECV) was assessed following neratinib treatment using protein microarrays (Kinexus, Canada). Z scores and percent changes from control (%CFC) were calculated between neratinib vs. control treatment samples at IC50. Alterations in gene expression were ascertained using AmpliSeq™ technology. Results: Of over 800 proteins evaluated, neratinib caused significant %CFC (>50%) increase in 78 targets (such as EGFR, vimentin) and a %CFC decrease in 56 targets across all endothelial cells (including ROCKI). When comparing changes between brain and vascular cells, there was a significant change in %CFC for 36 proteins, including β-catenin and FYN. Of interest β-catenin is involved in TJ regulation. Differential expression of 21 genes associated with TJ including TJP1, JAM2, MABI1, CLDN7 and CLDN10 was also observed following neratinib treatment of brain or vascular endothelial cells I comparison to vascular cells treated with neratinib. Conclusions: These results show that neratinib may alter both gene expression and phosphorylation status of a number of proteins linked to metastasis in human brain endothelial cells. Interestingly, several of these proteins are known to be involved in TJ regulation or function, suggesting that neratinib may modulate the activity of TJ in the BBB. Studies validating these findings are ongoing and may provide valuable insights into a new mode of action of neratinib for the treatment for cancers with brain metastasis. Citation Format: Tracey A. Martin, Sioned Owen, Dafydd A. Dart, Francesca Avogadri Connors, Alshad S. Lalani, Richard P. Bryce, Wen G. Jiang. Neratinib effects significant changes in human brain endothelial cells, demonstrating that it may have a therapeutic use in cancers with brain metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2894.