Molecular response of keloids to ionizing radiation: targeting FOXO1 radiosensitizes keloids

Abstract

Purpose

Keloids are benign dermal tumors that arise from abnormal wound healing processes following skin lesions. Surgical excision followed by radiotherapy plays an important role in the treatment of keloids. Nevertheless, radioresistance remains a serious impediment to treatment efficacy. Investigation of the molecular response of keloids to radiation may contribute to radiosensitizing strategies.

Materials and methods

Primary keloid fibroblasts from human keloids were isolated and irradiated with X-ray. The expression profiles of messenger RNA (mRNA) in nonradiated and irradiated primary keloid fibroblasts were measured by mRNA sequencing analysis. Then, we identified common motifs and corresponding transcription factors of dysregulated mRNAs by using bioinformatic analysis of the proximal promoters. Whereafter, GO and KEGG were used to analyze the functional enrichment of the differentially expressed genes.

Results

We found that radiation not only suppressed proliferation but also increased cell senescence of primary keloid fibroblasts. There were 184 mRNAs and 204 mRNAs that showed significant changes in 4 and 8 Gy irradiated primary keloid fibroblasts, respectively. Among them, 8 upregulated and 30 downregulated mRNAs showed consistent alterations in 4 and 8 Gy irradiated primary keloid fibroblasts. More importantly, the xForkhead box O1 (FOXO1) signaling pathway was involved in the irradiation response. Pretreatment with the FOXO1 signaling inhibitor AS1842856 significantly promoted LDH release, apoptosis and senescence of primary keloid fibroblasts following irradiation.

Conclusion

Our findings illustrated the molecular changes in human keloid fibroblasts in response to radiation, and FOXO1 pathway inhibition is expected to provide a novel strategy for the radiosensitization of keloids.

Keywords:

• Keloid
• ionizing radiation
• radiosensitizer
• fork
• head box O1 (FOXO1)

Author contributions

MH and XL conceived the experiments and designed the research. MH, XL, YL and WM performed the molecular biology experiments. SC, TY and YS analyzed and interpreted the data. DY provided general supervision. DY and SZ performed statistical analysis. SZ performed manuscript editing. All authors have read and approved the final manuscript.

Disclosure statement

The authors have no conflicting interests.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant [number 82073477 and 32071238]; Excellent Youth Project of Sichuan Province; Central Funds for Sichuan Province [number 2021ZYD0073] and the Young Talent Project of China National Nuclear Corporation.

Notes on contributors

Min Hong

Min Hong is a Research Scientist in Laboratory of Radiation Medicine, West China Second University Hospital, Sichuan University, Chengdu 610041, China. She is currently working in Qingdao Municipal Center for Disease Control and Prevention of Qingdao, Qingdao, Institute of Preventive Medicine, Qingdao, 266034, Shandong, China.

Xiaoqian Li

Xiaoqian Li is a Student of West China School of Basic Medical Sciences and Forensic Medicine, which belongs to Sichuan University. The lab, which she studied, belongs to West China Second University Hospital and West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University.

Yulan Liu

Yulan Liu is a Doctor of Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital.

Wei Mo

Wei Mo is a Postgraduate of State Key Lab of Radiation Medicine and Protection and School of Radiation Medicine and Protection, which belongs to Medical College of Soochow University.

Bin Shi

Bin Shi is a Student of West China School of Basic Medical Sciences and Forensic Medicine, which belongs to Sichuan University. The lab, which he studied, belongs to West China Second University Hospital and West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University.

Shigao Chen

Shigao Chen is a Doctor of Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital.

Tao Yan

Tao Yan is a Junior Research Assistant at West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University.

Yuhong Shi

Yuhong Shi is a Doctor of Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital.

Daojiang Yu

Daojiang Yu, Ph.D., Medical Director of Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital. He is a doctoral candidate at West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University.

Shuyu Zhang

Shuyu Zhang, Ph.D., is Head of the Lab of Radiation Medicine, which both belongs to West China Second University Hospital and West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University. Moreover, He is a Senior Researcher at Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital.