The level of spontaneous and radiation-induced DNA damage varies depending on genetic and environmental factors in human somatic cells. This variation may be associated with transcriptional changes in cells, allowing the use of gene expression levels as markers of individual sensitivity to mutagenic effects. This study aimed to identify and characterize differentially expressed genes (DEGs) in lymphocytes of individuals with various frequencies of endogenous γH2AX foci and radiation-induced micronuclei (n = 37). The low-focus group was characterized by 0.18 ± 0.02 endogenous γH2AX foci per cell and a 155.78 ± 47.19‰ radiation-induced micronucleus frequency. The high-focus group was characterized by 0.49 ± 0.07 foci/cell and a 78.44 ± 33.21‰ micronucleus frequency. Seven DEGs (ENST00000424415, CRNDE, ADAMTS1, ENST00000424084, EIF2A, PNPLA5, and FRG2C) (FDR < 0.2) were identified by gene expression analysis with microarrays. As the extracellular matrix metalloproteinase, ADAMTS1 is able to activate the latent form of TGFβ, and TGFβ is involved in radiation-induced cellular response; the effects of ADAMTS1 knockout and overexpression on the gene expression profile were further validated in adherent HeLa cells. Twenty-nine of 160 identified DEGs are involved in apoptosis, DNA DSB repair, G2/M cell cycle transition, and the TGFβ signaling pathway. Thus, ADAMTS1 may be useful as a potential target for antitumor therapy.

The effect of knockout and overexpression of the ADAMTS1 on the radiation-induced response in HeLa cell line was analyzed. The cell line with the ADAMTS1 gene knockout was created using the CRISPR/Cas9 genome editing technology. The ADAMTS1 gene overexpression was ensured by transient transfection of the plasmid containing the gene of interest. Clonogenic survival, micronuclei frequency, and the γH2AX and 53BP1 foci level after irradiation with 2–8 Gy of γ rays were assessed. It was shown that the HeLa cell line with the ADAMTS1 gene knockout was characterized by a 1.9-fold decrease in clonogenic survival after an irradiation dose of 2 Gy ( p < 0.05) and an increase in micronuclei frequency (55.3 ± 8.3‰) in comparison with intact HeLa (36.0 ± 7.2‰, p < 0.05), but did not differ in the DNA repair foci level. Transfection of the plasmid carrying the ADAMTS1 gene into HeLa cell line with the ADAMTS1 gene knockout led to a decrease in the radiation-induced micronuclei frequency from 55.3 ± 8.3 to 28.7 ± 10.3‰ ( p < 0.05), which was comparable with the micronuclei frequency in the original HeLa cell line after irradiation (36.0 ± 7.2‰). Our results indicate that the ADAMTS1 gene is involved in radiation-induced cellular response in the HeLa cell line.

In this study, the effect of the THBS1 gene knockout on the survival of human tumor cells, the frequency of spontaneous and radiation-induced micronuclei, and the expression profile of genes in the HeLa cell line was investigated. It was shown that the THBS1 gene knockout led to a decrease in the plating efficiency before and after irradiation (1.4-fold, p = 0.0002 and 1.7-fold, p = 0.00009, respectively) and an increase in the frequency of spontaneous and radiation-induced micronuclei (1.9-fold, p = 0.02 and 2.5-fold, p = 0.01, respectively). In addition, expression of genes involved in the DNA repair processes, apoptosis, and G2/M cell cycle checkpoint was changed after THBS1 knockout in comparison with the intact HeLa cell line. Thus, the THBS1 gene knockout leads to an increase in the radiosensitivity of the HeLa cell line. This indicates the possible role of the THBS1 gene in the regulation of a radiation-induced cellular response.

Проведен анализ выживаемости клеток, оценка уровня фокусов белков репарации ДНК и частоты радиационно-индуцированных микроядер в условиях дифференциальной экспрессии генов ADAMTS1, RBFOX2, THBS1 и WHSC1 в модельных системах in vitro и в лимфоцитах периферической крови человека. Полученные результаты указывают на потенциальную возможность использования уровня экспрессии данных генов для выявления индивидов с повышенной радиочувствительностью. In this study, we investigated the cell survival, the DNA repair foci level and the radiation-induced micronuclei frequency in the model systems in vitro and in the human peripheral blood lymphocytes with differential expression of ADAMTS1, RBFOX2, THBS1 and WHSC1 genes. The results indicate the potential opportunity of using these genes expression level to identify the individuals with increased radiosensitivity.

In this study, we investigated the cell survival, the DNA repair foci level and the radiation-induced micronuclei frequency in the model systems in vitro and in the human peripheral blood lymphocytes with differential expression of ADAMTS1, RBFOX2, THBS1 and WHSC1 genes. The results indicate the potential opportunity of using these genes expression level to identify the individuals with increased radiosensitivity.