Extracellular vesicles-transferred SBSN drives glioma aggressiveness by activating NF-κB via ANXA1-dependent ubiquitination of NEMO.

Glioma is the most common malignant primary brain tumor with aggressiveness and poor prognosis. Although extracellular vesicles (EVs)-based cell-to-cell communication mediates glioma progression, the key molecular mediators of this process are still not fully understood. Herein, we elucidated an EVs-mediated transfer of suprabasin (SBSN), leading to the aggressiveness and progression of glioma. High levels of SBSN were positively correlated with clinical grade, predicting poor clinical prognosis of patients. Upregulation of SBSN promoted, while silencing of SBSN suppressed tumorigenesis and aggressiveness of glioma cells in vivo. EVs-mediated transfer of SBSN resulted in an increase in SBSN levels, which promoted the aggressiveness of glioma cells by enhancing migration, invasion, and angiogenesis of recipient glioma cells. Mechanistically, SBSN activated NF-κB signaling by interacting with annexin A1, which further induced Lys63-linked and Met1-linear polyubiquitination of NF-κB essential modulator (NEMO). In conclusion, the communication of SBSN-containing EVs within glioma cells drives the formation and development of tumors by activating NF-κB pathway, which may provide potential therapeutic target for clinical intervention in glioma.

Overexpression of SHARPIN promotes tumor progression in ovarian cancer.

SHARPIN (Shank-associated RH domain interacting protein) plays an important role in tumorigenesis. However, its role in ovarian cancer remains largely unknown. To investigate this issue, we systematically analyzed the amplification and expression of the SHARPIN in the TCGA database. From the database, we found that SHARPIN was amplified in ovarian cancer compared to normal ovarian tissue, and the mRNA level of SHARPIN was significantly elevated in ovarian cancer compared to non-tumorigenic ovarian tissue. In addition, we observed similar results from ovarian cancer cell lines and clinical samples from ovarian cancer patients, which indicated that increased SHARPIN expression is associated with tumorigenesis in ovarian cancer. SHARPIN knockdown inhibited the migration and invasion of ovarian cancer cells, also inhibited cell cycle and promoted apoptosis, thereby suppressing cell proliferation. RNA-seq results showed that SHARPIN significantly increased the expression of P53 and P21 and decreased the expression of Cyclin D1 and c-Myc, all of which are involved in the regulation of cell proliferation. Subsequent mechanistic exploration revealed that SHARPIN knockdown increased the expression of caspases 3 and 9, leading to apoptosis of ovarian cancer cells. We also found that high expression of SHARPIN was associated with poor prognosis of ovarian cancer patients. Collectively, we demonstrated a positive correlation between SHARPIN and ovarian cancer progression and provide a basis for combined targeted therapy strategies for future ovarian cancer treatment.