Fibroblast growth factor receptor facilitates recurrence of minimal residual disease following trastuzumab emtansine therapy

Abstract

Trastuzumab-emtansine (T-DM1) is an antibody-drug conjugate (ADC) that efficiently delivers a potent microtubule inhibitor into HER2 overexpressing tumor cells. However, resistance to T-DM1 is emerging as a significant clinical problem. Continuous in vitro treatment of HER2-transformed mammary epithelial cells with T-DM1 did not elicit spontaneously resistant cells. However, induction of epithelial-mesenchymal transition (EMT) via pretreatment with TGF-β1 facilitated acquisition of T-DM1 resistance. Flow cytometric analyses indicated that induction of EMT decreased trastuzumab binding, prior to overt loss of HER2 expression. Kinome analyses of T-DM1 resistant cells indicated increased phosphorylation of ErbB1, ErbB4, and fibroblast blast growth factor receptor 1 (FGFR1). T-DM1 resistant cells failed to respond to the ErbB kinase inhibitors lapatinib and afatinib, but they acquired sensitivity to FIIN4, a covalent FGFR kinase inhibitor. In vivo, T-DM1 treatment led to robust regression of HER2-transformed tumors, but minimal residual disease (MRD) was still detectable via bioluminescent imaging. Upon cessation of the ADC relapse occurred and secondary tumors were resistant to additional rounds of T-DM1, but this recurrent tumor growth could be inhibited by FIIN4. Expression of FGFR1 was upregulated in T-DM1 resistant tumors, and ectopic overexpression of FGFR1 was sufficient to enhance tumor growth, diminish trastuzumab binding, and promote recurrence following T-DM1-induced MRD. Finally, patient-derived xenografts from a HER2 + breast cancer patient who had progressed on trastuzumab failed to respond to T-DM1, but tumor growth was significantly inhibited by FIIN4. Overall, our studies strongly support therapeutic combination of TDM1 and FGFR targeted agents in HER2 + breast cancer.Suppl. Fig. S1. HER2 expression is diminished upon acquisition of resistantance to TDM1. A, Ex-vivo subculture of HME2 tumors that recurred after T-DM1-induced minimal residual disease as shown in Figure 1. These cells failed to thrive in culture. B, HME2 parental cells and their in vitro-derived T-DM1 resistant (TDM1R) counterparts were fixed, permeabilized and stained for HER2. These cells were counter stained with DAPI to visualize the nucleus. C, HME2 parental cells (Par), those treated and recovered from TGF-b1 (Post-TGF-b), those treated and recovered from TGF-b1 and subsequently selected for by continuous treatment with T-DM1 (TDM1R Invitro), and primary culture from P3 HME2 tumors selected for resistance to T-DM1, as described in Figure 7a of the main text (TDM1R In-vivo), were assayed by immunoblot for expression of HER2 and b-tubulin (b-Tub) served as a loading control. Fig. S2. Enhanced FGFR expression upon acquisition of resistance to TDM1. A, Expression levels of FGFR1-4 in the NCI-N87 cells selected for resistant to TDM1. Data are extracted from a single RNA sequencing experiment and are normalized to the untreated control cells. B, Expression levels of FGFR1-4 in four different TDM1 resistant BT474 clones (C1-3 and C6). D...

Fibroblast growth factor receptor facilitates recurrence of minimal residual disease following trastuzumab emtansine therapy

“…P values for all experiments are indicated, values of <0.05 were considered significant. A preliminary version of this manuscript has been published as a preprint 34 .…”

“…The datasets generated and analyzed during the current study are available from the corresponding author, Dr. Michael Wendt (email address: mwendt@purdue.edu), upon reasonable request, as described in the following figshare metadata record: https://doi.org/10.6084/m9.figshare.13148360 35 . Kinome data are publicly available in Supplementary Data 1.…”

Crosstalk between HER2 and PD-1/PD-L1 in Breast Cancer: From Clinical Applications to Mathematical Models

“…In short, trastuzumab resistance is mediated by (1) impaired interaction of trastuzumab to HER2 (via MUC4, p95HER2, CDK2), (2) an altered or parallel intracellular PI3K/AKT/mTOR signaling pathway, (3) mutation of PIK3CA gene, and (4) higher levels of cyclin-E, fatty acid synthase (FASN), and/or NmU. Similarly, potential reasons for T-DM1 resistance include difficulties in binding with the receptor (due to MUC4, p95HER2), impaired receptor internalization, improper release of cytotoxic agent, and/or activation of parallel pathways [85,86]. All of the FDA-approved anti-HER2 drugs are associated with resistance development via one or more of the above-listed pathways.…”

“…As per available literature, potential predictive biomarkers that can be used to select patients who may benefit from combined treatment using HER2-targeted and PD-1/PD-L1 axis based therapeutic agents are (1) HER2 amplification/overexpression, (2) PD-1/PD-L1 expression, (3) presence of a greater number of TILs and fewer Tregs, (4) higher TMB (tumor mutation burden), (5) PTEN expression, and (6) expression of CD5, CD74, CD96, and CD226, to name only few [38,86,121,[131][132][133][134][135][136][137][138]. However, it is still not clear which combination of clinicopathological factors are most reliable predictive biomarkers to implement effective treatment protocols using anti-HER2 and/or PD-1/PD-L1 pathways [39,139].…”