Study on the Mechanism of IGFBP-3 in Glioma: A Multi-Omics Approach

Abstract

Objective: To explore the mechanism of action and therapeutic potential of IGFBP-3 in glioma, in order to provide new insights and strategies for the treatment of glioma.

Methods: Part I: Correlation analysis between IGFBP-3 and glioma. Firstly, a comprehensive analysis of IGFBP-3's expression patterns, prognostic value, immune infiltration, and clinical relevance is conducted using bioinformatics methods. Subsequently, validations are performed in clinical samples and serum to explore its potential as a biomarker and therapeutic target. Part II: In vitro cell experiments investigating the effects of IGFBP-3 on U87MG cell proliferation, apoptosis, invasion, and migration, and the potential molecular mechanisms involved in these processes. Part III: Utilizing advanced algorithms, a large number of radiological features potentially associated with IGFBP-3 are extracted from medical images, and pathological features potentially associated with IGFBP-3 are extracted from tissue specimens. Based on this, a radiopathological model is developed and validated to predict the expression level of IGFBP-3 in glioma patients.

Results: 1. IGFBP-3 is an unstable basic hydrophilic secretory protein with a nuclear localization signal, with a protein molecular formula of C1390H2230N418O422S21. Its secondary structure primarily consists of circular and helical structures, containing three main structural domains, 67 phosphorylation sites, and three N-glycosylation sites. It exerts biological effects through its nuclear localization signal, without having a transmembrane structural region. Its diverse biological functions depend on specific domains or motifs that bind to different molecules. In addition to its dependence on IGF, IGFBP-3 also interacts with different proteins on the cell surface or within the cell, exerting various biological activities through IGF-independent pathways. 2. The expression of IGFBP-3 is positively correlated with the WHO grading of gliomas, with high expression indicating poor prognosis in patients; it is an independent risk factor for the prognosis of glioma patients. 3. In a two-sample Mendelian randomization study, a significant negative correlation was found between IGFBP-3 and IGFALS. 4. IGFBP-3 is highly expressed in the DAOY and U87 glioblastoma cell lines, while its expression is lower in the D283 and U251 cell lines. 5. Overexpression and knockdown of IGFBP-3 had no significant effect on the proliferation and apoptosis of U87MG cells. Knockdown of IGFBP-3 weakened the invasion and migration abilities of U87MG cells; overexpression of IGFBP-3 enhanced the invasion and migration abilities of U87MG cells. Both overexpression and knockdown of IGFBP-3 inhibited the PI3K/AKT/mTOR pathway. 6. Cells in the IGFBP-3 overexpression group had more pseudopodia on the cell surface, which were dense and robust, and there was an increase in intracellular spherical protrusions. In the IGFBP-3+ overexpression rapamycin group, the number of pseudopodia decreased, the arrangement of intracellular spherical protrusions was disordered and fragmented, the cell surface became rough and uneven, and this group inhibited the expression of HIF-1α, COX-2, MMP-9, and VEGF, as well as the invasion and migration of U87MG cells. 7. An RPM model constructed based on the characteristics of radiomics and pathological omics can accurately predict the expression levels of IGFBP-3 in glioma patients.

Conclusion: IGFBP-3 is an independent risk factor for the prognosis of glioma and can serve as a biomarker for poor prognosis in glioma. In vitro cellular experiments have shown that knockdown of IGFBP-3 can inhibit the invasion and migration of U87MG cells. IGFBP-3 is involved in the PI3K/AKT/mTOR signaling pathway and affects the invasion and migration of glioma cells by regulating proteins such as HIF-1α, COX-2, and MMP-9. The radiopathological model has great potential in predicting the prognosis of glioma and guiding its treatment.

Funding: This work was supported by Key projects of Xinjiang Uygur Autonomous Region(Grant numbers: 2022D01D70). Natural Science Foundation of Xinjiang Uygur Autonomous Region (Grant numbers: 2022D01C257). Open project of Xinjiang Key Laboratory of Neurological Diseases Research (Grant numbers: XJDX1711-2204). Xinjiang Medical University Postgraduate Practice Innovation Project (CXCY2023001).

Declaration of Interest: The authors declare no competing interests.

Ethical Approval: This experiment upon the approval of the xinjiang medical university first affiliated
hospital ethics committee(No:20220309-180).

Keywords: Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3), Bioinformatics, Mendelian Randomization, Radiomics, Pathomics