Crizotinib Resistance Mediated by Autophagy Is Higher in the Stem-Like Cell Subset in ALK-Positive Anaplastic Large Cell Lymphoma, and This Effect Is MYC-Dependent

Chuquan Shang; Bardes Hassan; Moinul Haque; Yuqi Song; Jing Li; Dongzhe Liu; Eva Lipke; Will Chen; Sylvie Giuriato; Raymond Lai

doi:10.3390/cancers13020181

Crizotinib Resistance Mediated by Autophagy Is Higher in the Stem-Like Cell Subset in ALK-Positive Anaplastic Large Cell Lymphoma, and This Effect Is MYC-Dependent

Cancers (Basel). 2021 Jan 7;13(2):181. doi: 10.3390/cancers13020181.

Authors

Chuquan Shang¹, Bardes Hassan^{1

2}, Moinul Haque¹, Yuqi Song^{1

3}, Jing Li^{1

4}, Dongzhe Liu^{1

5

6}, Eva Lipke^{1

7}, Will Chen¹, Sylvie Giuriato⁸, Raymond Lai^{1

9}

Affiliations

¹ Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB T6G 2R3, Canada.
² Department of Pathology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt.
³ Norman Bethune Health Science Center of Jilin University, Changchun 130021, China.
⁴ Electron Microscopy Center, Basic Medical Science College, Harbin Medical University, Harbin 150080, China.
⁵ Department of Hematology and Oncology, Shenzhen University General Hospital, Shenzhen 518055, China.
⁶ Laboratory of Biology and Chemistry, Basic Medical Science College, Harbin Medical University, Harbin 150080, China.
⁷ Department of Life Sciences, Albstadt-Sigmaringen University, 72488 Sigmaringen, Germany.
⁸ CRCT, INSERM U1037-Université Toulouse III-Paul Sabatier-CNRS ERL5294, F-31037 Toulouse, France.
⁹ Department of Oncology, University of Alberta, Edmonton, AB T6G 2R3, Canada.

Abstract

Previously it was shown that autophagy contributes to crizotinib resistance in ALK-positive anaplastic large cell lymphoma (ALK + ALCL). We asked if autophagy is equally important in two distinct subsets of ALK + ALCL, namely Reporter Unresponsive (RU) and Reporter Responsive (RR), of which RR cells display stem-like properties. Autophagic flux was assessed with a fluorescence tagged LC3 reporter and immunoblots to detect endogenous LC3 alongside chloroquine, an autophagy inhibitor. The stem-like RR cells displayed significantly higher autophagic response upon crizotinib treatment. Their exaggerated autophagic response is cytoprotective against crizotinib, as inhibition of autophagy using chloroquine or shRNA against BECN1 or ATG7 led to a decrease in their viability. In contrast, autophagy inhibition in RU resulted in minimal changes. Since the differential protein expression of MYC is a regulator of the RU/RR dichotomy and is higher in RR cells, we asked if MYC regulates the autophagy-mediated cytoprotective effect. Inhibition of MYC in RR cells using shRNA significantly blunted crizotinib-induced autophagic response and effectively suppressed this cytoprotective effect. In conclusion, stem-like RR cells respond with rapid and intense autophagic flux which manifests with crizotinib resistance. For the first time, we have highlighted the direct role of MYC in regulating autophagy and its associated chemoresistance phenotype in ALK + ALCL stem-like cells.

Keywords: ALK + ALCL; MYC; autophagy; cancer stem-like cells; chloroquine; crizotinib; resistance.