Purpose: To explore whether antitumor immunoadjuvant OM-174 can stimulate immune cells to produce interferon-gamma (IFN-gamma) and thereby radiosensitize tumor cells.
Methods And Materials: Splenocytes from BALB/c mice were stimulated by OM-174 at plasma-achievable concentrations (0.03-3 mug/mL), and afterward analyzed for the expression and secretion of IFN-gamma by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Stimulated splenocytes were used as a source of IFN-gamma to radiosensitize hypoxic EMT-6 tumor cells through the cytokine-inducible isoform of nitric oxide synthase (iNOS).
Results: OM-174 activated the production of IFN-gamma at high levels that reached 70 ng/mL in normoxia (21% oxygen) and 27 ng/mL in tumor-relevant hypoxia (1% oxygen). This caused up to 2.1-fold radiosensitization of EMT-6 tumor cells, which was associated with the iNOS-mediated production of the radiosensitizing molecule nitric oxide, as confirmed by accumulation of its oxidative metabolite nitrite, Western blot analysis, and reverse transcriptase-polymerase chain reaction. Both iNOS activation and radiosensitization were counteracted by neutralizing antibodies against IFN-gamma. The same mechanism of radiosensitization through the IFN-gamma secretion pathway was identified for IL-12 + IL-18, which are known to mediate IFN-gamma responses. Hypoxia displayed a dual effect on the immune-tumor cell interaction, by downregulating the expression of the IFN-gamma gene while upregulating iNOS at transcriptional level.
Conclusion: Immunoadjuvant OM-174 is an efficient radiosensitizer of tumor cells through activation of the IFN-gamma secretion pathway in immune cells. This finding indicates a rationale for combining immunostimulatory and radiosensitizing strategies and extends the potential therapeutic applications of OM-174.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.ijrobp.2006.07.1381 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Target-switchable nanoprobe based on BRD4 inhibition for induction and dynamic visualization of the mitochondrial apoptotic pathway.
Biosens Bioelectron
January 2025
School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, China. Electronic address:
The exploration of the mitochondrial apoptotic pathway in living cells is of great significance for achieving tumor diagnosis and treatment. However, visualization of the mitochondrial apoptotic pathway induced by specific proteins has rarely been reported. In this paper, we designed and synthesized a fluorescent probe Cy-JQ1 based on the bromodomain-containing protein 4 (BRD4) inhibition.
View Article and Find Full Text PDFTargeted therapy for glioblastoma utilizing hyaluronic acid-engineered liposomes for adriamycin delivery.
Nanotechnology
January 2025
Nanjing Medical University, Department of Neurosurgery, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Nanjing, 210029, CHINA.
Glioblastoma (GBM) is a malignant tumor with highly heterogeneous and invasive characteristics leading to a poor prognosis. The CD44 molecule, which is highly expressed in GBM, has emerged as a highly sought-after biological marker. Therapeutic strategies targeting the cell membrane protein CD44 have emerged, demonstrating novel therapeutic potential.
View Article and Find Full Text PDFCell-Based Therapies in GI Cancers: Current Landscape and Future Directions.
Am Soc Clin Oncol Educ Book
January 2025
Department of Gastrointestinal Oncology, National Cancer Center Hospital East, Kashiwa, Japan.
Cell-based therapies have become integral to the routine clinical management of hematologic malignancies. Tumor-infiltrating lymphocyte (TIL) therapy has demonstrated efficacy in immunogenic solid tumors, such as melanoma. However, in the GI field, evidence supporting the clinical success of cell-based therapies is still awaited.
View Article and Find Full Text PDFMicroenvironment actuated CAR T cells improve solid tumor efficacy without toxicity.
Sci Adv
January 2025
Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
A major limiting factor in the success of chimeric antigen receptor (CAR) T cell therapy for the treatment of solid tumors is targeting tumor antigens also found on normal tissues. CAR T cells against GD2 induced rapid, fatal neurotoxicity because of CAR recognition of GD2 normal mouse brain tissue. To improve the selectivity of the CAR T cell, we engineered a synthetic Notch receptor that selectively expresses the CAR upon binding to P-selectin, a cell adhesion protein overexpressed in tumor neovasculature.
View Article and Find Full Text PDFWWC proteins-mediated compensatory mechanism restricts schwannomatosis driven by loss of function.
Sci Adv
January 2025
Institute of Pediatrics, Children's Hospital of Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.
NF2-related schwannomatosis, previously known as neurofibromatosis type 2, is a genetic disorder characterized by nerve tumors due to gene mutations. Mice with deletion develop schwannomas slowly with low penetrance, hence inconvenient for preclinical studies. Here, we show that NF2, by recruiting E3 ubiquitin ligases β-TrCP1/2, promotes WWC1-3 ubiquitination and degradation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!