PT  - JOURNAL ARTICLE
AU  - Yu Yu
AU  - Minzhen Tao
AU  - Libin Xu
AU  - Lei Cao
AU  - Baoyu Le
AU  - Na An
AU  - Jilin Dong
AU  - Yajie Xu
AU  - Baoxing Yang
AU  - Wei Li
AU  - Bing Liu
AU  - Qiong Wu
AU  - Yinying Lu
AU  - Zhen Xie
AU  - Xiaohua Lian
TI  - Systematic screening reveals synergistic interactions that overcome MAPK inhibitor resistance in cancer cells
AID  - 10.20892/j.issn.2095-3941.2020.0560
DP  - 2022 Feb 01
TA  - Cancer Biology & Medicine
PG  - 229--252
VI  - 19
IP  - 2
4099  - http://www.cancerbiomed.org/content/19/2/229.short
4100  - http://www.cancerbiomed.org/content/19/2/229.full
SO  - Cancer Biol Med2022 Feb 01; 19
AB  - Objective Effective adjuvant therapeutic strategies are urgently needed to overcome MAPK inhibitor (MAPKi) resistance, which is one of the most common forms of resistance that has emerged in many types of cancers. Here, we aimed to systematically identify the genetic interactions underlying MAPKi resistance, and to further investigate the mechanisms that produce the genetic interactions that generate synergistic MAPKi resistance.Methods We conducted a comprehensive pair-wise sgRNA-based high-throughput screening assay to identify synergistic interactions that sensitized cancer cells to MAPKi, and validated 3 genetic combinations through competitive growth, cell viability, and spheroid formation assays. We next conducted Kaplan-Meier survival analysis based on The Cancer Genome Atlas database and conducted immunohistochemistry to determine the clinical relevance of these synergistic combinations. We also investigated the MAPKi resistance mechanisms of these validated synergistic combinations by using co-immunoprecipitation, Western blot, qRT-PCR, and immunofluorescence assays.Results We constructed a systematic interaction network of MAPKi resistance and identified 3 novel synergistic combinations that effectively targeted MAPKi resistance (ITGB3 + IGF1R, ITGB3 + JNK, and HDGF + LGR5). We next analyzed their clinical relevance and the mechanisms by which they sensitized cancer cells to MAPKi exposure. Specifically, we discovered a novel protein complex, HDGF-LGR5, that adaptively responded to MAPKi to enhance cancer cell stemness, which was up- or downregulated by the inhibitors of ITGB3 + JNK or ITGB3 + IGF1R.Conclusions Pair-wise sgRNA library screening provided systematic insights into elucidating MAPKi resistance in cancer cells. ITGB3-+ IGF1R-targeting drugs (cilengitide + linsitinib) could be used as an effective therapy for suppressing the adaptive formation of the HDGF-LGR5 protein complex, which enhanced cancer stemness during MAPKi stress.