GZ17-6.02 and Pemetrexed Interact to Kill Osimertinib-Resistant NSCLC Cells That Express Mutant ERBB1 Proteins.

Laurence Booth,Cameron West,Paul Dent,Robert P Moore,Daniel Von Hoff

doi:10.3389/fonc.2021.711043

Abstract

We determined the molecular mechanisms by which the novel therapeutic GZ17-6.02 killed non-small cell lung cancer (NSCLC) cells. Erlotinib, afatinib, and osimertinib interacted with GZ17-6.02 to kill NSCLC cells expressing mutant EGFR proteins. GZ17-6.02 did not interact with any EGFR inhibitor to kill osimertinib-resistant cells. GZ17-6.02 interacted with the thymidylate synthase inhibitor pemetrexed to kill NSCLC cells expressing mutant ERBB1 proteins or mutant RAS proteins or cells that were resistant to EGFR inhibitors. The drugs interacted to activate ATM, the AMPK, and ULK1 and inactivate mTORC1, mTORC2, ERK1/2, AKT, eIF2α; and c-SRC. Knockdown of ATM or AMPKα1 prevented ULK1 activation. The drugs interacted to cause autophagosome formation followed by flux, which was significantly reduced by knockdown of ATM, AMPKα1, and eIF2α, or by expression of an activated mTOR protein. Knockdown of Beclin1, ATG5, or [BAX + BAK] partially though significantly reduced drug combination lethality as did expression of activated mTOR/AKT/MEK1 or over-expression of BCL-XL. Expression of dominant negative caspase 9 weakly reduced killing. The drug combination reduced the expression of HDAC2 and HDAC3, which correlated with lower PD-L1, IDO1, and ODC levels and increased MHCA expression. Collectively, our data support consideration of combining GZ17-6.02 and pemetrexed in osimertinib-resistant NSCLC.

Highlights

The drug GZ17-6.02 is undergoing phase I evaluation in solid tumor patients (NCT03775525)
We have previously shown that GZ17-6.02 interacted with 5-fluorouracil (5FU) to kill GI tumor cells, with doxorubicin to kill sarcoma cells and with [trametinib + dabrafenib] to kill cutaneous melanoma cells expressing B-RAF V600E [1, 2]
We determined whether GZ176.02 interacted with pemetrexed to kill other non-small cell lung cancer (NSCLC) cell lines, regardless of mutant RAS or ERBB1 expression; GZ17-6.02 and pemetrexed interacted to kill (Figure 2C)

Summary

Introduction

The drug GZ17-6.02 is undergoing phase I evaluation in solid tumor patients (NCT03775525). GZ17-6.02 has three components that are natural chemicals: curcumin (10%), isovanillin (77%), and harmine (13%) [1,2,3,4]. Our prior in vitro studies have used GZ176.02 with the basal concentration of curcumin set at 2.0 mM [1,2,3]. The most bio-active chemical isolated from these plants is harmine. Studies have shown that while harmine has anti-proliferative effects in tumor cells, the compound appears to lack any anti-proliferative biologic effects in non-transformed cells. Our new studies were performed to determine whether GZ17-6.02 could kill non-small cell lung cancer (NSCLC) cells expressing mutant activated forms of the EGF receptor (ERBB1)

Methods

Results

Conclusion