Polyploid/Multinucleated Giant and Slow-Cycling Cancer Cell Enrichment in Response to X-ray Irradiation of Human Glioblastoma Multiforme Cells Differing in Radioresistance and TP53/PTEN Status

• Published in: International journal of molecular sciences Vol. 24; no. 2; p. 1228
• Main Authors: Alhaddad, Lina, Chuprov-Netochin, Roman, Pustovalova, Margarita, Osipov, Andreyan N, Leonov, Sergey
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 08.01.2023; MDPI
• Subjects: Apoptosis; Brain cancer; Brain Neoplasms - genetics; Brain Neoplasms - metabolism; Brain Neoplasms - radiotherapy; Brain tumors; Cancer therapies; Cell division; Cell Line, Tumor; Chemotherapy; Cycles; Genotypes; Glioblastoma; Glioblastoma - genetics; Glioblastoma - metabolism; Glioblastoma - radiotherapy; glioblastoma multiforme; Humans; I.R. radiation; Ki-67 Antigen - metabolism; Low level; Metastasis; multinucleated giant cancer cell (MGCC); Mutation; Neuroimaging; p53; p53 Protein; polyploid giant cancer cell (PGCC); Polyploidy; Populations; PTEN Phosphohydrolase - genetics; PTEN Phosphohydrolase - metabolism; PTEN protein; Radiation therapy; Radiation tolerance; Radiation Tolerance - genetics; Radioresistance; Repopulation; Senescence; Transcription factors; Tumor Suppressor Protein p53 - genetics; Tumors; X ray irradiation; X-Rays; senescence; glioblastoma multiforme; multinucleated giant cancer cell (MGCC); polyploid giant cancer cell (PGCC); p63; neosis; p73; radioresistance; p53
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms24021228

Radioresistance compromises the efficacy of radiotherapy for glioblastoma multiforme (GBM), the most devastating and common brain tumor. The present study investigated the relationship between radiation tolerance and formation of polyploid/multinucleated giant (PGCC/MGCC) and quiescent/senescent slow-cycling cancer cells in human U-87, LN-229, and U-251 cell lines differing in status and radioresistance. We found significant enrichment in MGCC populations of U-87 and LN-229 cell lines, and generation of numerous small mononuclear (called Raju cells, or RJ cells) U-87-derived cells that eventually form cell colonies, in a process termed neosis, in response to X-ray irradiation (IR) at single acute therapeutic doses of 2-6 Gy. For the first time, single-cell high-content imaging and analysis of Ki-67- and EdU-coupled fluorescence demonstrated that the IR exposure dose-dependently augments two distinct GBM cell populations. Bifurcation of Ki-67 staining suggests fast-cycling and slow-cycling populations with a normal-sized nuclear area, and with an enlarged nuclear area, including one resembling the size of PGCC/MGCCs, that likely underlie the highest radioresistance and propensity for repopulation of U-87 cells. Proliferative activity and anchorage-independent survival of GBM cell lines seem to be related to neosis, low level of apoptosis, fraction of prematurely stress-induced senescent MGCCs, and the expression of p63 and p73, members of p53 family transcription factors, but not to the mutant 53. Collectively, our data support the importance of the genotype for the maintenance of cycling radioresistant U-87 cells to produce a significant amount of senescent MGCCs as an IR stress-induced adaptation response to therapeutic irradiation doses.