Evaluation of a strategy for tumor-initiating stem cell eradication in primary human glioblastoma cultures as a model

Abstract

Primary cultures of human glioblastoma were obtained from the surgical material of patients K. (female, 61 years, Ds: relapse of glioblastoma) and Zh. (female, 60 years, Ds: relapse of glioblastoma). The effectiveness of a new therapeutic approach aimed at destroying the cancer cell community was evaluated on the primary cell lines of human glioblastoma culture by employing a new strategy of tumor-initiating stem cell synchronization and a domestic strategy of their eradication "3+1". The key elements of the strategy were the following indicator results: (1) evaluation of the presence of tumor-initiating stem cells in a population of cells from analyzed cultures by their ability to internalize double-stranded labeled DNA (TAMRA+ cells); (2) determination of the reference time points of the repair cycle of DNA interstrand cross-links induced by cross-linking cytostatic mitomycin C; (3) evaluation of cell cycle synchronization; (4) determination of the time (day after therapy initiation) when TAMRA+ cells were synchronously present in phase G1/S of the cell cycle, sensitive to the therapy; and (5) establishment of the TAMRA+ (tumor-initiating stem cells) eradication schedule. The cultures were treated with cross-linking cytostatic mitomycin C and a compositional DNA preparation. After the treatments, cell division slows down, and the cultures degrade. The K cell line completely degraded within 30 days of observation. The cell number of the Zh culture fell to nearly one-third of the starting value by day 15 of observation. On day 15, this indicator constituted 1/7.45 for mitomycin C and 1/10.28 for mitomycin C + DNA with reference to the control. The main target of the mitomycin C + DNA regimen was TAMRA+ tumor-initiating stem cells of the glioblastoma cell populations. The action of mitomycin C alone or in the combination with DNA demonstrated effective elimination of TAMRA+ tumor-initiating stem cells and the whole primary cultures of human glioblastomas.

Efficacy of the new therapeutic approach in curing malignant neoplasms on the model of human glioblastoma

“…The peak number of DSBs was observed 18 h after exposure to MMC ( P < 0.001) ( Figure 1E ). This pattern differed from that obtained for the primary cell culture 33 ; thus, an independent therapeutic scheme for treating U87 cells based on the new data regarding the repair of MMC-induced ICLs has been developed ( Figure 1F ).…”

“…The first three exposures result in the large-scale caspase-activated DNase-dependent apoptosis of committed and partially stem-like tumor cells, as we have demonstrated in Krebs-2 and some other experimental tumors. The fourth terminal exposure is supposed to completely eliminate the remaining tumor cells, including the TAMRA+ CSCs, observed in the Krebs-2 model 28 , 31 , 33 .…”

“…Moreover, BBB also impedes the migration of activated immune cells from peripheral blood to the tumor node. It was shown that the time necessary to repair the CP-induced ICLs does not exceed 36 h 33 , which means that, on days 6–7 ( Figure 2A ; on days 6–7, cells are synchronized and accumulated in the subG1/G1 phases of the cell cycle, and the 7th day was chosen for the next scheduled CP administration), all DNA repair processes are completed and cells are “ready” for the next treatment. Moreover, low doses of ICL-inducing compound allow a significant fraction of cells to repair all lesions quite correctly and, as a result, to retain their functional properties and even acquire resistance to the compound used.…”

Theoretical premises of a “three in one” therapeutic approach to treat immunogenic and nonimmunogenic cancers: a narrative review

“…In parallel, addition of the DNAmix leads to a massive lysis of committed cancer cells. This technology has been successfully tested on several experimental mouse and human cancers and in 3 pilot clinical cases (6,8,(76)(77)(78)(79).…”

“…It has been incontrovertibly shown that systemic anticancer immunity is boosted by such therapy ( 6 , 8 , 77 ). Nonetheless, Karanahan technology is largely based on the eradication of TISCs and induction of massive apoptosis of committed cancer cells, rather than on anticancer immunity.…”