SOX4-BMI1 axis promotes non-small cell lung cancer progression and facilitates angiogenesis by suppressing ZNF24.

The incidence of lung cancer has become the highest among all cancer types globally, also standing as a leading cause of cancer-related deaths. Lung cancer is broadly divided into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), with the latter accounting for 85% of total cases. SRY-box transcription factor 4 (SOX4), a crucial transcription factor, has been found to play a key role in the development of various cancers. However, the association between SOX4 and NSCLC is still unclear. This study investigated the clinical relevance of SOX4 and its potential mechanisms in the progression of NSCLC. Analysis of our NSCLC patient cohort revealed a significant increase in SOX4 levels in cancerous tissues, indicating its role as an independent prognostic indicator for NSCLC. In vitro experiments demonstrated that elevated SOX4 expression facilitated NSCLC cell migration, invasion, and EMT. Functionally, SOX4 drives NSCLC progression by enhancing the transcription and expression of B-cell-specific moloney leukemia virus insertion site 1 (BMI1). The oncogenic impact of SOX4-induced BMI1 expression on NSCLC advancement was validated through both in vivo and in vitro studies. In addition, our findings showed that BMI1 promoted the ubiquitination of histone H2A (H2Aub), leading to decreased zinc finger protein 24 (ZNF24) expression, which subsequently triggered vascular endothelial growth factor A (VEGF-A) secretion in NSCLC cells, thereby promoting NSCLC angiogenesis. Moreover, we evaluated the therapeutic potential of a BMI1 inhibitor in combination with Bevacizumab for NSCLC treatment using orthotopic models. The data presented in our study reveal a previously unrecognized role of the SOX4-BMI1 axis in promoting NSCLC progression and angiogenesis. This research significantly contributes to our knowledge of the interplay between SOX4 and BMI1 in NSCLC, potentially paving the way for the development of targeted therapies for this disease.