Macropinocytosis supports the metabolic requirement of RAS‐transformed pancreatic ductal adenocarcinoma cells (PDACs). However, regulators of RAS‐transformation (activation) that lead to macropinocytosis have not been identified. Herein, we report that UBAP2 (ubiquitin‐binding associated protein 2), regulates the activation of KRAS and macropinocytosis in pancreatic cancer. We demonstrate that UBAP2 is highly expressed in both pancreatic cancer cell lines and tumor tissues of PDAC patients. The expression of UBAP2 is associated with poor overall survival in several cancers, including PDAC. Silencing UBAP2 decreases the levels of activated KRAS, and inhibits macropinocytosis, and tumor growth in vivo. Using a UBAP2‐deletion construct, we demonstrate that the UBA‐domain of UBAP2 is critical for the regulation of macropinocytosis and maintaining the levels of activated KRAS. In addition, UBAP2 regulates RAS downstream signaling and helps maintain RAS in the GTP‐bound form. However, the exact mechanism by which UBAP2 regulates KRAS activation is unknown and needs further investigation. Thus, UBAP2 may be exploited as a potential therapeutic target to inhibit macropinocytosis and tumor growth in activated KRAS‐driven cancers.

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease with a relapsing-remitting course that affects multiple organs and tissues leading to a wide range of clinical manifestations. 1 SLE affects women more commonly than men with a ratio of 9:1, most commonly occurring in the child bearing age. 2,3 One of the most serious manifestations of SLE is renal disease (lupus nephritis), ranging from asymptomatic hematuria or proteinuria to serious nephritic and nephrotic syndrome, which can progress to acute and chronic renal failure. 4 There is a high risk of morbidity and mortality associated with renal involvement in SLE; thus, this manifestation can require immediate and intensive management. 5 Glucocorticoids are used for acute treatment, but more aggressive