MYO9B deficiency promoted head and neck tumor progression through HIF1α/MYC/STAT2 signaling pathway.

Background: Myosin, a protein family primarily involved in muscle contraction and cell movement, plays critical roles in various biological processes. Increasing evidence suggests its implication in tumor development and progression. However, the underlying mechanism remains poorly understood. Our study aimed to explore the role and molecular mechanism of myosin IXB (MYO9B) in head and neck squamous cell carcinoma (HNSC) development.

Methods: Utilizing The Cancer Genome Atlas (TCGA) database (n = 24) and analyzing clinical HNSC tissues (n = 24), we investigated the correlation between myosin encoding genes and HNSC progression. Cell proliferation and migration were assessed using CCK8 and Transwell assays to elucidate the tumor suppressive role of MYO9B. Additionally, Western blotting and immunostaining were conducted to evaluate the activation of HIF1α/c-Myc/STAT2 signaling. A 3D Matrigel Primary tumor cell culture model was established to assess the cisplatin resistance of HNSC cells.

Results: We found that MYO9B deficiency predicted poor prognosis in HNSC patients. In vitro, inhibiting MYO9B enhanced the proliferative and migratory characteristics of HNSC cell lines. Mechanistically, our study showed that MYO9B deficiency upregulated HIF1α signaling, leading to c-Myc upregulation, which induced stem-like phenotypes in cancer cells and HNSC progression. Furthermore, c-Myc upregulated downstream STAT2 signaling, contributing to cisplatin resistance in HNSC cells. Blocking STAT2 signaling improved cisplatin outcomes in primary MYO9B-high HNSC tissues from patients.

Conclusion: Our study highlights the tumor suppressive role of MYO9B through HI1F1α/c-Myc/STAT2 in HNSC, suggesting its potential as a diagnostic indicator and therapeutic target for clinical intervention.