Hypoxia enhances IL-8 signaling through inhibiting miR-128-3p expression in glioblastomas.

Abstract

Glioblastoma multiforme (GBM) is an aggressive type of brain tumor known for its hypoxic microenvironment. Understanding the dysregulated mechanisms in hypoxic GBM is crucial for its effective treatment. Through data mining of The Cancer Genome Atlas (TCGA) with hypoxia enrichment scores and in vitro experiments, miR-128-3p was negatively correlated with hypoxia signaling and the epithelial-mesenchymal transition (EMT). Additionally, lower miR-128-3p levels existed in hypoxic GBM, leading to desensitizing temozolomide (TMZ)'s efficacy, a first-line therapeutic drug for GBM. Overexpressing miR-128-3p enhanced both the in vitro and in vivo sensitivity of hypoxic gliomas to TMZ treatment. Mechanistically, HIF-1α suppressed miR-128-3p expression in hypoxic GBM. Through establishing miR-128-3p-mediated transcriptomic profiles and data mining, interleukin (IL)-8 was selected. IL-8 respectively showed positive and negative correlations with hypoxia and miR-128-3p, and was associated with poor TMZ therapeutic results in GBM. Elevated miR-128-3p, which targets both the 3'-untranslated region (UTR) and 5'UTR of IL-8, resulted in suppression of IL-8 expression. Moreover, IL-8 was validated to be involved in HIF-1α/miR-128-3p-regulated TMZ sensitivity and the EMT in hypoxic GBM cells. Collectively, the HIF-1α/miR-128-3p/IL-8 signaling pathway plays a critical role in promoting the progression of hypoxic GBM. Targeting this signaling pathway holds promise as a potential therapeutic strategy.