1. Upregulation of IGF2R evades lysosomal dysfunction-induced apoptosis of cervical cancer cells via transport of cathepsins
- Author
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Eiichiro Tominaga, Takashi Takeda, Kouji Banno, Rie Komatsuzaki, Daisuke Aoki, Yusuke Kobayashi, Fumiko Chiwaki, Kanako Nakamura, Masaya Ono, Hiroki Sasaki, Masayuki Komatsu, and Kosuke Tsuji
- Subjects
Cancer Research ,Tumor suppressor gene ,Immunology ,Golgi Apparatus ,Uterine Cervical Neoplasms ,Apoptosis ,Biology ,Receptor, IGF Type 2 ,Article ,Receptor, IGF Type 1 ,Transcriptome ,Cellular and Molecular Neuroscience ,Targeted therapies ,Downregulation and upregulation ,Mitophagy ,Biomarkers, Tumor ,medicine ,Humans ,RNA, Messenger ,lcsh:QH573-671 ,Insulin-like growth factor 1 receptor ,Cervical cancer ,Cisplatin ,lcsh:Cytology ,Autophagy ,Cell Biology ,Middle Aged ,medicine.disease ,Cathepsins ,Up-Regulation ,Gene Knockdown Techniques ,Cancer research ,Female ,Lysosomes ,Reactive Oxygen Species ,medicine.drug - Abstract
Cervical cancer is the most common gynecological malignancy in the world; however, the survival rates of advanced-stage and recurrent cervical cancer patients remain poor. The multifaced protein insulin-like growth factor 2 receptor (IGF2R) has various ligands, represented as IGF-2 and mannose-6-phosphate (M6P)-tagged proteins. Regarding its antagonistic activity as an IGF1R signal, IGF2R is currently considered a tumor suppressor gene, whereas its significance as an M6P receptor is still unclear. Here, on the basis of transcriptome analysis of TCGA and GEO open datasets, we show that IGF2R is upregulated and correlated with poor prognosis in cervical cancer. Several experiments using cervical cancer cell lines revealed that IGF2R depletion induced apoptosis, decreased cell viability, and increased vulnerability to certain anticancer drug cisplatin. In contrast to its negligible impact in IGF1R signaling, loss of IGF2R disrupted the Golgi-to-lysosome transport of M6P-tagged cathepsins, resulting in decreased lysosomal activity, with their abnormal accumulation and dysfunction of both autophagy and mitophagy, which cause the accumulation of misfolded proteins and production of reactive oxygen species. Taken together, IGF2R has an oncogenic role through transportation of M6P-tagged cargo in cervical cancer and can be used as a predictive biomarker for prognostic classification.
- Published
- 2019
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