11
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Gamma Radiation-Attenuated Toxoplasma gondii Provokes Apoptosis in Ehrlich Ascites Carcinoma-Bearing Mice Generating Long-Lasting Immunity

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Purpose:

          Pathological angiogenesis and apoptosis evasions are common hallmarks of cancer. A different approach to the antitumor effect of parasitic diseases caused by certain protozoans and helminthes had been adopted in recent years as they can affect many cancer characteristics. The present work is an attempt to assess the effect of gamma radiation-attenuated Toxoplasma gondii ME49 as an antiapoptotic and angiogenic regulator modifier on tumor growth aimed at improving cancer protective protocols.

          Methods:

          Attenuated Toxoplasma gondii ME49 was administered orally to mice 2 weeks before inoculation with Ehrlich ascites carcinoma to allow stimulation of the immune response. Hepatic histopathology and immune responses were determined for each group.

          Results:

          Marked suppression of the tumor proliferation with induction of long-lasting immunity by stimulating interferon γ and downregulating transforming growth factor β. The level of tumor promoting inflammatory markers (STAT-3 and tumor necrosis factor α), the angiogenic factors (vascular endothelial growth factor A, integrin, and matrix metallopeptidase 2 and matrix metallopeptidase 9), as well as nitric oxide concentration were significantly decreased. This was collimated with an improvement in apoptotic regulators (cytochrome-c, Bax, Bak, and caspase 3) in liver tissues of vaccinated mice group compared to Ehrlich ascites carcinoma-bearing one. Moreover, the histopathological investigations confirmed this improvement.

          Conclusion:

          Hence, there is an evidence of potency of radiation attenuated Toxoplasma vaccine in immune activation and targeting tumor cell that can be used as a prophylactic or an adjuvant in combination with chemotherapeutic drugs.

          Related collections

          Most cited references48

          • Record: found
          • Abstract: found
          • Article: not found

          STAT3 is a potential modulator of HIF-1-mediated VEGF expression in human renal carcinoma cells.

          Aberrantly enhanced vascular endothelial growth factor (VEGF) gene expression is associated with increased tumor growth and metastatic spread of solid malignancies, including human renal carcinomas. Persistent activation of STAT3 is linked to tumor-associated angiogenesis, but underlying mechanisms remain unclear. Therefore, we examined whether STAT3 modulates the stability and activity of hypoxia-inducible factor-1alpha (HIF-1alpha), and in turn enhances VEGF expression. We found that STAT3 was activated in ischemic rat kidneys and hypoxic human renal carcinoma cells. We also found that hypoxia-induced activation of STAT3 transactivated the VEGF promoter and increased the expression of VEGF transcripts. Consistent with these findings, STAT3 inhibition attenuated the hypoxic induction of VEGF. Interestingly, activated STAT3 increased HIF-1alpha protein levels due to the HIF-1alpha stability by blocking HIF-1alpha degradation and accelerated its de novo synthesis. The novel interaction of STAT3 with HIF-1alpha was identified in hypoxic renal carcinoma cells. Furthermore, hypoxia recruited STAT3, HIF-1alpha, and p300 to the VEGF promoter and induced histone H3 acetylation. Therefore, these findings provide compelling evidence that a causal relationship exists between STAT3 activation and HIF-1-dependent angiogenesis and suggest that therapeutic modalities designed to disrupt STAT3 signaling hold considerable promise for the blocking tumor growth and enhancing apoptosis of cancer cells and tissues.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            Interferon gamma in cancer immunotherapy

            Abstract Immune system can recognize self vs transformed self. That is why cancer immunotherapy achieves notable benefits in a wide variety of cancers. Recently, several papers reported that immune checkpoint blockade therapy led to upregulation of IFNγ and in turn clearance of tumor cells. In this review, we conducted an extensive literature search of recent 5‐year studies about the roles of IFNγ signaling in both tumor immune surveillance and immune evasion. In addition to well‐known functions, IFNγ signaling also induces tumor ischemia and homeostasis program, resulting in tumor clearance and tumor escape, respectively. The yin and the yang of IFNγ signaling are summarized. Thus, this review helps us to comprehensively understand the roles of IFNγ in tumor immunity, which contributes to better design and management of clinical immunotherapy approaches.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Enforced dimerization of BAX results in its translocation, mitochondrial dysfunction and apoptosis.

              Expression of the pro-apoptotic molecule BAX has been shown to induce cell death. While BAX forms both homo- and heterodimers, questions remain concerning its native conformation in vivo and which moiety is functionally active. Here we demonstrate that a physiologic death stimulus, the withdrawal of interleukin-3 (IL-3), resulted in the translocation of monomeric BAX from the cytosol to the mitochondria where it could be cross-linked as a BAX homodimer. In contrast, cells protected by BCL-2 demonstrated a block in this process in that BAX did not redistribute or homodimerize in response to a death signal. To test the functional consequence of BAX dimerization, we expressed a chimeric FKBP-BAX molecule. Enforced dimerization of FKBP-BAX by the bivalent ligand FK1012 resulted in its translocation to mitochondria and induced apoptosis. Caspases were activated yet caspase inhibitors did not block death; cytochrome c was not released detectably despite the induction of mitochondrial dysfunction. Moreover, enforced dimerization of BAX overrode the protection by BCL-XL and IL-3 to kill cells. These data support a model in which a death signal results in the activation of BAX. This conformational change in BAX manifests in its translocation, mitochondrial membrane insertion and homodimerization, and a program of mitochondrial dysfunction that results in cell death.
                Bookmark

                Author and article information

                Journal
                Technol Cancer Res Treat
                Technol. Cancer Res. Treat
                TCT
                sptct
                Technology in Cancer Research & Treatment
                SAGE Publications (Sage CA: Los Angeles, CA )
                1533-0346
                1533-0338
                22 June 2020
                2020
                : 19
                : 1533033820926593
                Affiliations
                [1 ]Health Radiation Research Department, National Center for Radiation Research and Technology (NCRRT)-Atomic Energy Authority (AEA), Cairo, Egypt
                [2 ]Radiation Biology Department, National Center for Radiation Research and Technology, Atomic Energy authority, Cairo, Egypt
                Author notes
                [*]Nermeen M. Elbakary, Radiation Biology Department, National Center for Radiation Research and Technology, Atomic Energy authority, 3 Ahmed Al Zomor St, Al Zohour Sector, Cairo 11787, Egypt. Email: nermeen_ahmed11@ 123456yahoo.com
                Author information
                https://orcid.org/0000-0002-0128-3159
                Article
                10.1177_1533033820926593
                10.1177/1533033820926593
                7309383
                32567499
                dcca5638-8aa5-494a-a82c-78736d15e219
                © The Author(s) 2020

                This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License ( https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages ( https://us.sagepub.com/en-us/nam/open-access-at-sage).

                History
                : 30 January 2020
                : 27 March 2020
                : 16 April 2020
                Categories
                Original Article
                Custom metadata
                January-December 2020
                ts3

                toxoplasma gondii,gamma radiation,ifn-γ,stat-3,vegf-a,angiogenic,apoptotic regulator

                Comments

                Comment on this article