Ovarian antibodies among SLE women with premature menopause after cyclophosphamide.

BACKGROUND: Women with systemic lupus erythematosus (SLE) are at risk of premature ovarian failure when treated with cyclophosphamide. This risk is increased when autoimmune thyroid disease is present. We undertook this study to determine whether the presence of ovarian autoimmunity also increased the risk of early ovarian failure among women receiving cyclophosphamide. METHODS: We examined the records of women enrolled in the Lupus Family Registry and Repository, a cross-sectional study of ~3300 SLE subjects, for treatment with cyclophosphamide as well as menopausal status. We defined premature menopause as permanent, spontaneous cessation of menstruation before age 45. We measured anti-ovarian antibodies by enzyme-linked immunosorbent assay using stored sera. RESULTS: There were 258 women treated with cyclophosphamide in whom presence of absence or premature menopause could by defined. A total of 169 (65.6%) had premature ovarian failure, while 89 (34.6%) did not. While anti-ovarian antibodies were present in a small percentage of patients, there was no association of premature menopause to either level of these antibodies (16.2 ± 20.3 units vs 17.4 ± 21.7 units, P = NS by Fisher's exact test), or positivity on this testing (11 of 169 [6.5%] positive vs 8 of 89 [8.9%], χ2  = 0.53, P = .46, 95% CI 0.95-1.1). Neither renal disease nor hypothyroidism increased the risk of premature ovarian failure in these women receiving cyclophosphamide. CONCLUSION: Anti-ovarian antibodies among women with SLE are not associated with premature ovarian failure after treatment with cyclophosphamide.

Ubiquitin-binding associated protein 2 regulates KRAS activation and macropinocytosis in pancreatic cancer.

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.