Madamsetty, Vijay Sagar

Schematic representation demonstrating the fabrication and in vivo evaluation of an immune-modulatory nano-formulation consisting of irinotecan and curcumin in immune-competent mouse models of pancreatic adenocarcinoma.

Abstract Glycogen synthase kinase-3 (GSK3) is a ubiquitously expressed serine-threonine protein kinase involved in multiple cellular functions ranging from the control of glycogen metabolism to transcriptional regulation. We have previously demonstrated that GSK-3β is overexpressed in human pancreatic ductal adenocarcinoma (PDAC) and aberrant nuclear accumulation of GSK-3β serves as a hallmark of poorly differentiated PDAC. Moreover, genetic ablation of GSK-3β or GSK-3 inhibition led to PDAC tumor cell killing, identifying GSK-3β as a therapeutic target in PDAC. Herein, we describe a novel GSK-3 inhibitor, 9-ING-41. The effect of 9-ING-41 on tumor cell growth was tested using several PDAC and patient-derived xenograft (PDX) cell lines in vitro and in vivo using an orthotopic pancreatic cancer animal model. Interestingly, 9-ING-41 treatment resulted in the stabilization of cyclin B levels as well as enhanced serine-10 phosphorylated histone H3 (pS10HH3) and consequently M phase arrest and blocked mitotic exit. The prolonged M phase arrest induced mitotic catastrophe in pancreatic cancer cell lines and inhibited in vitro colony formation. An in vivo orthotopic pancreatic cancer animal model study using PDX-derived cell lines demonstrated that 9-ING-41 hindered tumor growth in combination with several standard chemotherapeutic agents. Significantly, we found that 9-ING-41 treatment impaired the DNA damage response pathway activated by Gemcitabine in pancreatic cancer cell lines. In conclusion, our study indicates that GSK-3 plays an important role in pancreatic cancer progression and 9-ING-41 in combination with existing gemcitabine or irinotecan could be a new strategy for treating patients with PDAC. Citation Format: Li Ding, Jin-san Zhang, John R. Dube, Vijay S. Madamsetty, Daniel M. Schmitt, Debabrata Mukhopadhyay, Daniel D. Billadeau. The glycogen synthase kinase-3 inhibitor, 9-ING-41, synergizes with chemotherapy to inhibit pancreatic tumor growth in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2926.

ABSTRACT Dimethylarginine dimethylaminohydrolases (DDAHs) are known to degrade asymmetric dimethylarginine, an endogenous inhibitor of NOS, and maintain vascular homeostasis; however, the regulatory pathways of DDAHs remain unclear. In this study, we aimed to define the role of transmembrane glycoprotein neuropilin‐1 (NRP1) in the expression of DDAHs and investigate the potential roles of NRP1 in regulation of blood pressure. Short hairpin RNA–mediated knockdown of NRP1 reduced the level and mRNA stability of DDAH1 but not DDAH2 in HUVECs, whereas overexpression of NRP1 increased the mRNA stability of DDAH1. Meanwhile, mesenteric arteries and lung vascular endothelial cells of tamoxifen‐inducible endothelial cell–specific NRP1 knockout mice exhibited decreased expression of DDAH1 and slightly increased expression of DDAH2. Mechanistically, the regulation of NRP1 on DDAH1 expression is mediated by a posttranscriptional mechanism involving miR‐219‐5p in HUVECs. Although the endothelial cell–specific NRP1 knockout mice did not exhibit any significant change in blood pressure at the basal level, they were more sensitive to low‐dose angiotensin II infusion–induced increases in blood pressure. Our results show that NRP1 is required for full expression of DDAH1 in endothelial cells and that NRP1 contributes to protection from low‐dose angiotensin II–induced increases in blood pressure.—Wang, Y., Wang, E., Zhang, Y., Madamsetty, V. S., Ji, B., Radisky, D. C., Grande, J. P., Misra, S., Mukhopadhyay, D. Neuropilin‐1 maintains dimethylarginine dimethylaminohydrolase 1 expression in endothelial cells, and contributes to protection from angiotensin II–induced hypertension. FASEB J. 33, 494–500 (2019). www.fasebj.org