Volume 7 Issue 10, Oct 2022:
Article
Elaiophylin triggers paraptosis and preferentially kills ovarian cancer drug-resistant cells by inducing MAPK hyperactivation
Guan-Nan Li,Xue-Jiao Zhao,Zhen Wang,Meng-Shi Luo,Shen-Nan Shi,Dan-Mei Yan,Hua-Yi Li,Jia-Hao Liu,Yang Yang,Jia-Hong Tan,Ze-Yu Zhang,Ru-Qi Chen,Hui-Ling Lai,Xiao-Yuan Huang
ORCID: orcid.org/0000-0002-7684-6294,Jian-Feng Zhou
ORCID: orcid.org/0000-0002-1332-9230,Ding Ma,Yong Fang &…Qing-Lei Gao
ORCID: orcid.org/0000-0002-9448-3423
Finely tuned mitogen-activated protein kinase (MAPK) signaling is important for cancer cell survival. Perturbations that push cells out of the MAPK fitness zone result in cell death. Previously, in a screen of the North China Pharmaceutical Group Corporation’s pure compound library of microbial origin, we identified elaiophylin as an autophagy inhibitor. Here, we demonstrated a new role for elaiophylin in inducing excessive endoplasmic reticulum (ER) stress, ER-derived cytoplasmic vacuolization, and consequent paraptosis by hyperactivating the MAPK pathway in multiple cancer cells. Genome-wide CRISPR/Cas9 knockout library screening identified SHP2, an upstream intermediary of the MAPK pathway, as a critical target in elaiophylin-induced paraptosis. The cellular thermal shift assay (CETSA) and surface plasmon resonance (SPR) assay further confirmed the direct binding between the SHP2 and elaiophylin. Inhibition of the SHP2/SOS1/MAPK pathway through SHP2 knockdown or pharmacological inhibitors distinctly attenuated elaiophylin-induced paraptosis and autophagy inhibition. Interestingly, elaiophylin markedly increased the already-elevated MAPK levels and preferentially killed drug-resistant cells with enhanced basal MAPK levels. Elaiophylin overcame drug resistance by triggering paraptosis in multiple tumor-bearing mouse models resistant to platinum, taxane, or PARPi, suggesting that elaiophylin might offer a reasonable therapeutic strategy for refractory ovarian cancer.
