Melittin inhibits the expression of key genes involved in tumor microenvironment formation by suppressing HIF-1α signaling in breast cancer cells

Abstract

Purpose: HIF-1α has critical roles in formation of Tumor microenvironment by regulating genes involved in angiogenesis and anaerobic respiration. TME fuels tumors growth and metastasis and presents therapy with several challenges. Therefore, we aimed to investigate if Melittin disrupts HIF-1α signaling pathway in breast adenocarcinoma cell line MDA-MB-231.Methods: breast adenocarcinoma cell line MDA-MB-231 was cultured in presence of different doses of Melittin and MTT assay was carried out to measure Melittin's cytotoxic. Cells were exposed to 5% C 2 to mimic hypoxic conditions and Melittin. Western blot was used to measure HIF-1α protein levels. Gene expression analysis was performed using real-time PCR to measure relative mRNA abundance of genes involved in tumor microenvironment formation.Findings: Our results revealed that Melittin effectively inhibits HIF-1α at transcriptional and translation/post-translational level. HIF-1α protein and mRNA level was signi cantly decreased in Melittin-treated groups. It is found that inhibition of HIF-1α by Melittin is through downregulation of NFκB gene expression. Furthermore, gene expression analysis showed a downregulation in VEGFA and LDHA expression due to inhibition of HIF-1α protein by Melittin. In addition, cell toxicity assay showed that Melittin inhibits the growth of MDA-MB-231 cell line through activation of extrinsic and intrinsic apoptotic pathways by upregulating TNF and BAX expression.Conclusions: Melittin suppresses the expression of genes responsible for formation of TME physiological hallmarks by suppressing HIF-1α signaling pathway. Our results suggest that Melittin can modulate tumor microenvironment by inhibition of VEGFA and LDHA.

Melitina: o uso do principal componente da peçonha de abelha no combate de linhagens de células tumorais pulmonares

“…Furthermore, the use of melittin in these same strains has already been shown to inhibit the epithelial-mesenchymal transition of tumor cells 45 , corroborating the findings of Jeong et al 36 . Experiments using cervical carcinoma and mammary carcinoma cell lines also showed a relationship between the suppressive action of melittin on the expression of VEGF and HIF-1α 46,47 and its inhibitory effect on migration and invasion of tumor cells, confirming the findings of Zhang and Chen 34 .…”

“…It is formed by 26 amino acids 10 and is the main active component of apitoxin 19 . Recent preclinical studies (in vitro, in vivo and in silico) have conducted experiments and demonstrated the anticancer effects of melittin through different mechanisms of action in cell cultures of osteosarcoma 20, gastric carcinoma 21,22 , mammary carcinoma 23,24,25 , urothelial carcinoma 26 and melanoma 27 . Its high non-selective cytotoxic activity makes it a promising natural molecule for the development of new technologies and drugs for cancer treatment.…”

Pharmacological effects and mechanisms of bee venom and its main components: Recent progress and perspective

“…MEL also showed the potential to promote mitofusin-1 (Mfn1) and dynamin-related protein 1 (Drp1) expression and apoptosis in 4T1 cells ( Moghaddam et al, 2020 ). After 5% O 2 induction in MDA-MB-231 cells, the hypoxia-inducible factor-1α (HIF-1α) signaling pathway was inhibited by MEL and the expression of NF-κB, HIF-1α, vascular endothelial growth factor A (VEGFA) and lactate dehydrogenase A (LDHA) decreased, while the expression of Bax and tumor necrosis factor-α (TNF-α) was reversed, ultimately disrupting the tumor microenvironment (TME) of cancer cells and activating the phenomenon of apoptosis ( Mir Hassani et al, 2021 ).…”

Co-Targeting Tumor Angiogenesis and Immunosuppressive Tumor Microenvironment: A Perspective in Ethnopharmacology

“…Melittin (MEL), a polypeptide and the capital ingredient of honey bee venom, declined HIF-1α/VEGF levels via the suppression of ERK and mTOR/p70S6K signaling ( Shin et al, 2013 ). It downregulated NF-κB to inhibit the HIF-1α/VEGFA and LDHA expression that caused angiogenesis and descent pH via anaerobic metabolism, in TME, respectively ( Mir Hassani et al, 2021 ). CDDO-Me (Bardoxolone methyl), an analog of the natural triterpenoids oleanolic acid, the methyl-ester of the 2-cyano-3,12-dioxooleana-1,9 (11)-dien-28-oic acid (CDDO), have been abundantly advised for pharmacological applications, including tumor interference ( Borella et al, 2019 ).…”