Nuclear Transglutaminase 2 interacts with topoisomerase II⍺ to promote DNA damage repair in lung cancer cells

Abstract

Background To block repairs of DNA damages, especially the DNA double strand break (DSB) repair, can be used to induce cancer cell death. DSB repair depends on a sequential activation of DNA repair factors that may be potentially targeted for clinical cancer therapy. Up to now, many protein components of DSB repair complex remain unclear or poorly characterized. In this study, we discovered that Transglutaminase 2 (TG2) acted as a new component of DSB repair complex. Methods A bioinformatic analysis was performed to identify DNA damage relative genes from dataset from The Cancer Genome Atlas. Immunofluorescence and confocal microscopy were used to monitor the protein localization and recruitment kinetics. Furthermore, immunoprecipitation and mass spectrometry analysis were performed to determine protein interaction of both full-length and fragments or mutants in distinct domain. In situ lung cancer model was used to study the effects cancer therapy in vivo. Results After DSB induction, cytoplasmic TG2 was extensively mobilized and translocated into nucleus after phosphorylated at T162 site by DNA-PKcs. Nuclear TG2 quickly accumulated at DSB sites and directly interacting with Topoisomerase IIα (TOPOIIα) with its TGase domain to promote DSB repair. TG2 deficient cells lost capacity of DSB repair and become susceptible to ionizing radiation. Specific inhibition of TG2-TOPOIIα interaction by glucosamine also significantly inhibited DSB repair, which increased sensitivity in lung cancer cells and engrafted lung cancers. Conclusions These findings elucidate new mechanism of TG2 in DSB repair trough directly interacting with TOPOIIα, inhibition of which provided potential target for overcoming cancer resistance.

PRDM15 interacts with DNA-PK-Ku complex to promote radioresistance in rectal cancer by facilitating DNA damage repair

“…With the continuous development of biotechnology, complex models including carcinogenic induction model, genetically engineered mouse model and PDX model have emerged, which can make up for the above de ciencies. (39)(40)(41) In this study, we rstly used CDX model, and found that tumors derived from PRDM15-KD cells are more sensitive to radiotherapy than tumor derived from PRDM15-NC cells. However, neither the subcutaneous model nor in situ rectal cancer model can re ect the real environment.…”

“…Co-immunoprecipitation were performed to determine the interaction between proteins after irradiation as previous described (19). Brie y, for co-IP, eight hours after HCT116 cells were irradiated at a dose of 8 Gy, proteins were extracted.…”

PRDM15 interacts with DNA-PK-Ku complex to promote radioresistance in rectal cancer by facilitating DNA damage repair

“…However, these components play an important role in tumor resistance, invasion, metastasis and recurrence. With the continuous development of biotechnology, complex models including carcinogenic induction model, genetically engineered mouse model and PDX model have emerged, which can make up for the above deficiencies [ 40 – 42 ]. In this study, we firstly used CDX model, and found that tumors derived from PRDM15-KD cells are more sensitive to radiotherapy than tumor derived from PRDM15-NC cells.…”

“…Co-immunoprecipitation were performed to determine the interaction between proteins after IR as previous described [ 19 ]. Briefly, for Co-IP, 8 h after HCT116 cells were irradiated at a dose of 8 Gy, proteins were extracted.…”

New method for discrimination of multiple primary lung cancer and metastatic lung cancer

“…There is substantial evidence that there are individual differences in the ability of endogenous and exogenous carcinogens to DNA damage, which contributes to cancer risk 6 . The DNA repair capacity of patients with lung cancer is lower than that of normal controls, which further increases the risk of lung cancer 7,8 …”