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  • SPb RAACI  (2)
  • 1
    In: Medical Immunology (Russia), SPb RAACI, Vol. 25, No. 3 ( 2023-06-01), p. 605-610
    Abstract: Membrane molecules PD-L1 and PD-L2, ligands of T lymphocytes PD1 receptor, perform immunoregulatory functions. Their binding to the receptor leads to inhibition of proliferation, reduction of cytokine production, cytotoxic response, and apoptosis of T lymphocytes. The cells of many tumors, regardless of their histogenesis, express PD-L1 molecules, thus limiting the development of an anti-tumor immune response. Glioblastomas are highly malignant recurrent tumors of the central nervous system. The main sources of glioblastoma recurrence are resistant tumor cells initially present in gliomas with heterogeneous cellular composition, as well as resistant cells that are formed during therapy. Increasing the dose of cytostatic drugs or radiation during relapse therapy is not effective in glioblastomas. It has been shown for a number of tumors, including ovarian cancer and non-small cell lung cancer, that drugs preventing PD-L1/PD1 interaction are effective in the treatment of neoplasms resistant to chemo- and radiotherapy. Immunotherapy using drugs that inhibit the binding of PD-L molecules to their receptor is considered as a way to overcome the resistance of glioblastomas to therapy. The aim of this work was to assess the level of PD-L1 and PD-L2 gene expression in resistant glioblastoma cells lines A172, R1, T2 and T98G, which resumed proliferation after exposure to the maximum for each line, sublethal doses of cytostatic drugs (fotemustine and temozolomide), fractionated or single gamma irradiation. A172 line belongs to glioblastomas that are highly sensitive to these influences, T98G is a highly resistant cell line, while R1 and T2 lines occupy an intermediate position. In intact glioblastoma A172, R1, and T2 cells the level of PD-L1 and PD-L2 gene expression was equally high, while in T98G cells it was significantly lower. Exposure of A172 and R1 glioblastoma lines to cytostatic drugs or irradiation did not significantly change the level of PD-L1 and PD-L2 genes expression typical for intact cells. In T2 glioblastoma cells, and especially in T98G cells, a significant increase in expression of these genes was found, most pronounced for PD-L2 gene. This increase in expression may indicate an enhanced malignancy of resistant T2 and T98G cells. High expression of the genes responsible for the production of PD-L1 and PD-L2, which limit the cytotoxic response against tumor cells, is a prerequisite for the use of drugs targeted against PD-L1 and PD-L2 for the elimination of resistant cells in glioblastoma.
    Type of Medium: Online Resource
    ISSN: 2313-741X , 1563-0625
    Language: Unknown
    Publisher: SPb RAACI
    Publication Date: 2023
    detail.hit.zdb_id: 3041761-2
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  • 2
    In: Medical Immunology (Russia), SPb RAACI, Vol. 25, No. 3 ( 2023-06-01), p. 611-616
    Abstract: One of the modern methods of treating patients with primary and recurrent brain tumors is radiosurgical irradiation using Gamma Knife, which allows therapeutic doses to be delivered to tumors not exceeding 2.5 cm in diameter in 1–2 sessions. Tumor cells on the periphery of this tissue volume that receive lower radiation doses can resume proliferation and serve as a source of recurrence. The increase of radiation dose may cause necroses formation and a worsening prognosis. The properties of glioblastoma cells that survive and resume proliferation long after stereotactic irradiation are still poorly known. The aim of the work was to evaluate the expression of IL-6 and IL-8 by glioblastoma A172, R1, T2, and T98G cell lines that resumed proliferation after sublethal Gamma Knife irradiation. Cells were irradiated once at doses ranging from 6 to 16 Gy, and then cultured for 40 days. Cell number was counted weekly; lethal and sublethal irradiation doses for each glioblastoma cell line were determined. In cultures descendant from proliferation of single most resistant cells, the level of IL-6 and IL-8 secretion after 96 hours cultivation (ng/1000 cells) was determined by ELISA. The cells of all four glioblastoma lines secreted IL-6 and IL-8 into culture medium. The highest production of cytokines, never before demonstrated for glioblastomas, was discovered in R1 cells. Glioblastoma T2 also had high interleukin production levels. In contrast to these lines, glioblastoma A172 (highly sensitive to the action of cytostatic drugs and radiation) secreted IL-6 at 30 times lower level than R1 cells. Glioblastoma T98G (highly resistant to the action of cytostatic drugs and radiation) also exhibited low interleukins production level. R1, T2, and T98G glioblastoma cells that resumed proliferation after irradiation had increased secretion of IL-6 and, to a lesser extent, IL-8. The dependence of cytokine production increase on irradiation dose for these cells was not linear. In contrast, A172 cells reduced IL-6 and IL-8 secretion under irradiation. The multidirectional changes in IL-6 and IL-8 production by cells of different glioblastoma lines were long-term and persisted for more than a month. The presented results cast doubt on the possibility to use IL-6 and IL-8 production by glioblastoma cells as potential biomarkers for early diagnosis, therapy monitoring as well as prognostic markers of the disease course.
    Type of Medium: Online Resource
    ISSN: 2313-741X , 1563-0625
    Language: Unknown
    Publisher: SPb RAACI
    Publication Date: 2023
    detail.hit.zdb_id: 3041761-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
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