SPLUNC1 regulates LPS-induced progression of nasopharyngeal carcinoma and proliferation of myeloid-derived suppressor cells

UBR5 metabolically reprograms nasopharyngeal carcinoma cells to promote glycolysis and M2 polarization via SPLUNC1 signaling

Nasopharyngeal carcinoma (NPC) is the most common cancer originating in nasopharynx. Metabolic reprogramming plays a critical role in tumor progression. Exploring mechanisms underlying metabolic reprogramming contributes to deeper understanding of NPC pathogenesis. Here, we found downregulation of RORA and SPLUNC1 in NPC, and RORA downregulation indicates poor prognosis. RORA binds to SPLUNC1 promoter to induce its transcription, and RORA overexpression inhibits cell proliferation and glycolysis by directly upregulating SPLUNC1. UBR5 inhibits RORA via promoting RORA ubiquitination and degradation, and UBR5 silencing represses proliferation and glycolysis in NPC. Additionally, METTL14, which is highly expressed in NPC, facilitates UBR5 mRNA stability by promoting its m6A modification through IGF2BP2. UBR5/RORA/SPLUNC1 axis facilitates M2 polarization by activating the GPR132 signaling. UBR5 silencing inhibits tumor growth, glycolysis and M2 polarization through RORA/SPLUNC1 signaling in mice. In conclusion, UBR5 promotes proliferation, glycolysis and M2 polarization by metabolically reprograming NPC cells through suppression of the RORA/SPLUNC1 signaling.

Lipopolysaccharide-Educated Cancer-Associated Fibroblasts Facilitate Malignant Progression of Ovarian Cancer Cells via the NF-kB/IL-6/JAK2 Signal Transduction

Gram-negative bacteria increase in ovarian cancer (OC) tissues, but its association with OC progression remains largely unknown. The present study aimed to investigate whether and how cancer-associated fibroblasts (CAFs) pretreated by the main components of bacterial outer membrane lipopolysaccharide (LPS) influence the malignancy of OC cells. Specifically, the culture medium of LPS-preconditioned CAFs (LPS-CM) further accelerated cell proliferation, colony formation and tumorigenesis of OC cells SKOV3 and HEY A8, compared with culture medium of CAFs. Next, we found that LPS pretreatment activated the nuclear factor-kappa B (NF-kB) pathway in CAFs to secret cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6), vascular endothelial growth factor (VEGF), etc. Neutralization of IL-6 in LPS-CM abolished the promoting effect of LPS-CM on cell proliferation, survival and epithelial-mesenchymal transition (EMT) in SKOV3 and HEY A8 cells. Mechanistically, LPS-CM activated the Janus kinases 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, while application with JAK2 inhibitor also reversed the promoting effect of LPS-CM on malignancy of OC cells. In summary, LPS-pretreated CAFs IL-6-dependently accelerate OC progression via activating the JAK2/STAT3 signal pathway, which enriches our understanding of the molecular mechanisms underlying ovaries-colonized gram-negative bacteria in OC progression.