JmjC-KDMs KDM3A and KDM6B modulate radioresistance under hypoxic conditions in esophageal squamous cell carcinoma

• Published in: Cell death & disease Vol. 11; no. 12; pp. 1068 - 16
• Main Authors: Macedo-Silva, Catarina, Miranda-Gonçalves, Vera, Lameirinhas, Ana, Lencart, Joana, Pereira, Alexandre, Lobo, João, Guimarães, Rita, Martins, Ana Teresa, Henrique, Rui, Bravo, Isabel, Jerónimo, Carmen
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14-12-2020; Springer Nature B.V; Nature Publishing Group
• Subjects: 13; 13/1; 13/105; 13/2; 13/51; 14; 14/105; 14/35; 14/63; 45/77; 692/53/2423; 692/699/67; 82; 82/80; Antibodies; Apoptosis; Apoptosis - drug effects; Apoptosis - genetics; Apoptosis - radiation effects; Biochemistry; Biomarkers, Tumor - metabolism; Biomedical and Life Sciences; Cell Biology; Cell Culture; Cell Line, Tumor; Cell migration; Cell Movement - drug effects; Cell Movement - genetics; Cell Movement - radiation effects; Cell Proliferation - drug effects; Cell Proliferation - radiation effects; Cell survival; DNA Damage; DNA Repair - drug effects; Epigenetics; Esophageal cancer; Esophageal Neoplasms - genetics; Esophageal Neoplasms - metabolism; Esophageal Neoplasms - pathology; Esophageal Squamous Cell Carcinoma - genetics; Esophageal Squamous Cell Carcinoma - metabolism; Esophageal Squamous Cell Carcinoma - pathology; Esophagus; Gene Expression Regulation, Neoplastic - drug effects; Gene Expression Regulation, Neoplastic - radiation effects; Histones; Humans; Hydroxyquinolines - pharmacology; Hypoxia; Hypoxia-inducible factor 1a; Immunofluorescence; Immunology; Ionizing radiation; Jumonji Domain-Containing Histone Demethylases - genetics; Jumonji Domain-Containing Histone Demethylases - metabolism; Life Sciences; Lysine; Medical prognosis; Post-translation; Radiation therapy; Radiation Tolerance - drug effects; Radiation, Ionizing; Radioresistance; Radiosensitivity; Squamous cell carcinoma; Tumor Hypoxia - drug effects; Tumor Hypoxia - genetics; Tumor Hypoxia - radiation effects; Tumors
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-020-03279-y

Esophageal squamous cell carcinoma (ESCC), the most frequent esophageal cancer (EC) subtype, entails dismal prognosis. Hypoxia, a common feature of advanced ESCC, is involved in resistance to radiotherapy (RT). RT response in hypoxia might be modulated through epigenetic mechanisms, constituting novel targets to improve patient outcome. Post-translational methylation in histone can be partially modulated by histone lysine demethylases (KDMs), which specifically removes methyl groups in certain lysine residues. KDMs deregulation was associated with tumor aggressiveness and therapy failure. Thus, we sought to unveil the role of Jumonji C domain histone lysine demethylases (JmjC-KDMs) in ESCC radioresistance acquisition. The effectiveness of RT upon ESCC cells under hypoxic conditions was assessed by colony formation assay. KDM3A/KDM6B expression, and respective H3K9me2 and H3K27me3 target marks, were evaluated by RT-qPCR, Western blot, and immunofluorescence. Effect of JmjC-KDM inhibitor IOX1, as well as
KDM3A
knockdown, in in vitro functional cell behavior and RT response was assessed in ESCC under hypoxic conditions. In vivo effect of combined IOX1 and ionizing radiation treatment was evaluated in ESCC cells using CAM assay. KDM3A, KDM6B, HIF-1α, and CAIX immunoexpression was assessed in primary ESCC and normal esophagus. Herein, we found that hypoxia promoted ESCC radioresistance through increased KDM3A/KDM6B expression, enhancing cell survival and migration and decreasing DNA damage and apoptosis, in vitro. Exposure to IOX1 reverted these features, increasing ESCC radiosensitivity and decreasing ESCC microtumors size, in vivo. KDM3A was upregulated in ESCC tissues compared to the normal esophagus, associating and colocalizing with hypoxic markers (HIF-1α and CAIX). Therefore, KDM3A upregulation in ESCC cell lines and primary tumors associated with hypoxia, playing a critical role in EC aggressiveness and radioresistance. KDM3A targeting, concomitant with conventional RT, constitutes a promising strategy to improve ESCC patients’ survival.