Evaluating the Effect of Metformin on Histone Modifications in Glioblastoma Multiforme Cell Line
Project no. 31897 · Status: Kapanmış (Yayın bekleniyor) · 2023
Summary
<p>Objective: Glioblastoma multiforme (GBM) accounts for about 48% of malignant tumors of the central nervous system and its surgical treatment is limited. Hence, many therapeutic agents have been investigated and some are used routinely in the treatment of GBM. One such agent is metformin, which is studied both as an adjuvant with some chemotherapeutic agents and as a single adjuvant therapy in GBM. Some studies reported that metformin has an anti-cancer effect and improves the prognosis of GBM patients. Metformin has been shown to act through the AMPK signaling pathway; hence, it is closely related to several critical cellular pathways that get dysregulated in carcinogenesis. Therefore, it may be likely that AMPK-related or unrelated epigenetic changes can contribute to the anticancer effects of metformin on GBM. Histone modification changes are well-established in the pathogenesis of GBM and possibly linked to the prognosis. Thus, the present study aimed to investigate whether the metformin-induced histone modification changes in the U87 MG cell line would be involved in its anti-cancer effects.</p><p>Materials and Methods: Cytotoxicity tests were carried out to determine the IC50 value for U87 MG cell lines. Apoptosis and cell cycle evaluations were conducted. Afterward, the changes of 21 different histone modifications after metformin treatment were evaluated with an ELISA-like method using the total H3 and specific histone modification antibodies. For a better understanding of the observed data from the histone modification analyses (p<0.05), mRNA expressions of 86 genes encoding enzymes responsible for histone modifications was quantified.</p><p>Results: It was observed that metformin was able to increase the apoptosis of U87 MG cells by 6.16 fold compared to the control group. Metformin caused cell cycle arrest at the G0/G1 and S phases in GBM cells. It also led to rapid upregulation of H3S10ph histone modification in the GBM cells. The expression levels of AURKB and SETD2 genes were significantly increased upon treatment with metformin.</p><p>Conclusion: The upregulation of the H3S10ph modification may be due to the increased expression of AURKB. Still, it is thought not to contribute to the anticancer effects of metformin on GBM. In contrast, the upregulation of SETD2 transcription is thought to contribute to the anticancer effects of metformin. Although the H3S10ph increase may be a dose-dependent metformin effect, further studies are needed to understand the consequences of this alteration.</p>