Jumonji domain-containing protein 2B silencing induces DNA damage response via STAT3 pathway in colorectal cancer.
BACKGROUND
Jumonji domain-containing protein 2B (JMJD2B), directly targeted by hypoxia-inducible factor 1α, maintains the histone methylation balance important for the transcriptional activation of many oncogenes. Jumonji domain-containing protein 2B has been implicated in colorectal cancer (CRC) progression; however, the mechanism remains unclear.


METHODS
Immunofluorescence and western blotting detected phosphorylated histone H2AX, characteristic of double-strand breaks, and comet assay was used to investigate DNA damage, in CRC cells after JMJD2B small interfering RNA (siRNA) transfection. We assessed the resulting in vitro responses, that is, cell cycle progression, apoptosis, and senescence coupled with JMJD2B silencing-induced DNA damage, studying the regulatory role of signal transducers and activators of transcription 3 (STAT3). The JMJD2B silencing anti-cancer effect was determined using an in vivo CRC xenograft model.


RESULTS
Jumonji domain-containing protein 2B knockdown induced DNA damage via ataxia telangiectasia-mutated (ATM) and ATM and Rad3-related pathway activation, resulting in cell cycle arrest, apoptosis, and senescence in both normoxia and hypoxia. Signal transducers and activators of transcription 3 suppression by JMJD2B silencing enhanced DNA damage. Intratumoural injection of JMJD2B siRNA suppressed tumour growth in vivo and activated the DNA damage response (DDR).


CONCLUSIONS
Jumonji domain-containing protein 2B has an essential role in cancer cell survival and tumour growth via DDR mediation, which STAT3 partially regulates, suggesting that JMJD2B is a potential anti-cancer target.
Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai 200001, PR China.
L
L
Chen
Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai 200001, PR China.
L
L
Fu
Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai 200001, PR China.
X
X
Kong
Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai 200001, PR China.
J
J
Xu
Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai 200001, PR China.
Z
Z
Wang
Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai 200001, PR China.
X
X
Ma
Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-0034, Japan.
Y
Y
Akiyama
Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai 200001, PR China.
Y
Y
Chen
Division of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai 200001, PR China.
J
J
Fang
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D064007:Ataxia Telangiectasia Mutated Proteins / Q000235:genetics; D059447:Cell Cycle Checkpoints / Q000235:genetics; D015687:Cell Hypoxia / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D016922:Cellular Senescence / Q000235:genetics; D015179:Colorectal Neoplasms / Q000235:genetics*; D004249:DNA Damage / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D018450:Disease Progression; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D056484:Jumonji Domain-Containing Histone Demethylases / Q000235:genetics*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010766:Phosphorylation; D034622:RNA Interference; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D015533:Transcriptional Activation
C468783:H2AX protein, human; C497442:HIF1A protein, human; D006657:Histones; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D056484:Jumonji Domain-Containing Histone Demethylases; C523637:KDM4B protein, human; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins