Inhibitory Effects of the Deep Underground Low Background Radiation Environment on the Proliferation and Migration of NP69 Human Nasopharyngeal Epithelial Cells and the Underlying Mechanisms
Abstract
Objective
To investigate the effects of low background radiation environments in deep underground settings on the biological behavior of NP69 human nasopharyngeal epithelial cells (NP69 cells) and the underlying molecular mechanisms.
Methods
A parallel control experimental design was adopted and NP69 cells were synchronously cultured in settings of three underground depths at the China in situ Deep-Underground Facility & Life Observatory (DeUFO)—ground level (DeUFO-0 m), 1000 m underground (DeUFO-1000 m), and 1500 m underground (DeUFO-1500 m). Changes in cell proliferation and migration capabilities were assessed using the Cell Counting Kit-8 (CCK-8) assay and scratch assay, respectively. High-throughput RNA sequencing (RNA-Seq) was performed to identify differentially expressed genes (DEGs). Functional annotation and pathway enrichment analysis of the DEGs were performed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases.
Results
CCK-8 assay revealed that, after 72 h of culture, the absorbance value of the DeUFO-0 m group was 1.35 times and 1.27 times those of the those of the DeUFO-1000 m and DeUFO-1500 m groups, respectively (both P < 0.0001). After 96 h of culture, the absorbance value of the DeUFO-0 m group was 1.52 times and 1.41 times those of the DeUFO-1000 m and DeUFO-1500 m groups, respectively (both P < 0.0001). Colony formation assays revealed that the number of cell colonies in the DeUFO-0 m group was 1.59 times and 1.27 times those in the DeUFO-1000 m group and DeUFO-1500 m group, respectively (both P < 0.001). The scratch assay revealed that the 36-hour wound healing rate of the DeUFO-0 m group was 2.22 times and 4.00 times those of the DeUFO-1000 m group and DeUFO-1500 m group, respectively (both P < 0.0001). Transwell assays revealed that the number of migrating cells in the DeUFO-0 m group was 2.08 times and 2.56 times those in the DeUFO-1000 m group and DeUFO-1500 m group, respectively (both P < 0.0001). Transcriptome sequencing analysis revealed consistent upregulation of CELF2, CELF4, CGB8, GRHL2, and DMRTA2 genes in the DeUFO-1000 m and DeUFO-1500 m groups. Pathway enrichment analysis indicated significant enrichment of extracellular matrix (ECM) remodeling-associated pathways and gene expression regulation pathways in the experimental groups (false discovery rate [FDR] < 0.05).
Conclusion
The low background radiation environment in deep underground settings suppresses the proliferation and migration activities of NP69 cells by mediating ECM remodeling and post-transcriptional regulatory mechanisms through the regulation of target genes such as the CELF family. This study provides experimental evidence for establishing a dose-response relationship between environmental radiation and cellular effects.
Keywords: Deep underground medicine, Low background radiation environment, NP69 human nasopharyngeal epithelial cells, Cell proliferation/migration, Transcriptomics
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PAN Z, GUO M, CUI G, et al. Estimation of natural radiation background levels and public dose in china. Radiat Prot, 1992(4): 251-259. LINDELL B, SOWBY D. The 1958 UNSCEAR report. J Radiol Prot, 2008, 28: 277-282. doi: 10.1088/0952-4746/28/3/R01.
MORCIANO P, CIPRESSA F, PORRAZZO A, et al. Fruit flies provide new insights in low-radiation background biology at the INFN underground gran sasso national laboratory (LNGS). Radiat Res, 2018, 190: 217-225. doi: 10.1667/RR15083.1.
WADSWORTH J, COCKELL C S, MURPHY A S, et al. There's plenty of room at the bottom: low radiation as a biological extreme. Front Astron Space Sci, 2020, 7: 50. doi: 10.3389/fspas.2020.00050.
DOBRZYNSKI L, FORNALSKI K W, FEINENDEGEN L E. Cancer mortality among people living in areas with various levels of natural background radiation. Dose Response, 2015, 13: 1559325815592391. doi: 10.1177/1559325815592391.
LEHRER S, ROSENZWEIG K E. Lung cancer hormesis in high impact states where nuclear testing occurred. Clin Lung Cancer, 2015, 16: 152-155. doi: 10.1016/j.cllc.2014.09.010.
LAMPE N, BRETON V, SARRAMIA D, et al. Understanding low radiation background biology through controlled evolution experiments. Evol Appl, 2017, 10: 658-666. doi: 10.1111/eva.12491.
DENG L, YIN Q, LIU S, et al. MicroRNA-613 enhances nasopharyngeal carcinoma cell radiosensitivity via the DNA methyltransferase 3B/tissue inhibitor of matrix metalloproteinase-3/signal transducer and activator of transcription-1/forkhead box o-1 axis. Dis Markers, 2022, 2022: 5699275. doi: 10.1155/2022/5699275.
XIE H P, LIU J F, GAO M Z, et al. The research advancement and conception of the deep-underground medicine. J Sichuan Univ (Med Sci), 2018, 49 (2): 163-168.
BAI Y N, SUN X R, WEN Q, et al. Effects of extreme environments on human sleep. J Sichuan Univ (Med Sci), 2024, 55 (4): 1034-1043. doi: 10. 12182/20240760402.
LIU Y, GAO Y, CHENG J, et al. Transcriptome analysis of well-differentiated laryngeal squamous cell carcinoma cells in below-background environment. Ann Transl Med, 2022, 10: 824. doi: 10.21037/atm-22-2997.
LIU J, MA T, GAO M, et al. Proteomic characterization of proliferation inhibition of well-differentiated laryngeal squamous cell carcinoma cells under below-background radiation in a deep underground environment. Front Public Health, 2020, 8: 584964. doi: 10.3389/fpubh.2020.584964.
LIU J, MA T, GAO M, et al. Proteomics provides insights into the inhibition of Chinese hamster V79 cell proliferation in the deep underground environment. Sci Rep, 2020, 10: 14921. doi: 10.1038/s41598-020-71154-z.
MORCIANO P, IORIO R, IOVINO D, et al. Effects of reduced natural background radiation on Drosophila melanogaster growth and development as revealed by the FLYINGLOW program. J Cell Physiol, 2018, 233: 23-29. doi: 10.1002/jcp.25889.
CASTILLO H, SCHODERBEK D, DULAL S, et al. Stress induction in the bacteria Shewanella oneidensis and Deinococcus radiodurans in response to below-background ionizing radiation. Int J Radiat Biol, 2015, 91: 749-756. doi: 10.3109/09553002.2015.1062571.
SMITH G B, GROF Y, NAVARRETTE A, et al. Exploring biological effects of low level radiation from the other side of background. Health Phys, 2011, 100: 263-265. doi: 10.1097/hp.0b013e318208cd44.
CASTILLO H, SMITH G B. Below-background ionizing radiation as an environmental cue for bacteria. Frontiers in Microbiology, 2017, 8. doi: 10.3389/fmicb.2017.00177.
PENG S, CAI X, CHEN J, et al. The role of CELF family in neurodevelopment and neurodevelopmental disorders. Neurobiol Dis, 2024, 197: 106525. doi: 10.1016/j.nbd.2024.106525.
FORRESTER-GAUNTLETT B, PETERS L, OBACK B. Grainyhead-like 2 is required for morphological integrity of mouse embryonic stem cells and orderly formation of inner ear-like organoids. Front Cell Dev Biol, 2023, 11: 1112069. doi: 10.3389/fcell.2023.1112069.
SHEN X, ANIRUDHAN J, FATIMA A, et al. Evidence that dmrta2 acts through repression of pax6 in cortical patterning and identification of a mutation impairing DNA recognition associated with microcephaly in human. eNeuro, 2025, 12 (6): ENEURO. 0377-24.2025. doi: 10.1523/ENEURO.0377-24.2025.
NAGIRNAJA L, VENCLOVAS C, RULL K, et al. Structural and functional analysis of rare missense mutations in human chorionic gonadotrophin beta-subunit. Mol Hum Reprod, 2012, 18: 379-390. doi: 10.1093/molehr/gas018.
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