Date Submitted
9-12-2023
Faculty Advisor
Ehab Sarsour, Ph.D.
Second Faculty Advisor
Asma Zaidi, Ph.D.
Third Faculty Advisor
Eugene Konorev, Ph.D.
Abstract
The mean age of pancreatic adenocarcinoma (PDAC) diagnosis is 70 years. Pancreatic cancer is desmoplastic; most of the tumor microenvironment consists of fibroblasts. Previously we showed that older quiescent fibroblasts, compared to younger ones, have significant changes in their lipid metabolism. Specifically, there is an increased expression of the oxygenase 12-LOX [arachidonic acid 12-lipoxygenase] and its product 12-(S)-HETE [12-(S)-hydroxy-5,8,10,14-eicosatetraenoic acid], which is an inflammatory mitogenic mediator. We have shown that 12-(S)-HETE increases PDAC proliferation and confers resistance to therapy. We have also shown that patients with higher 12-(S)-HETE serum levels have higher metastatic and recurrence risk. Currently, the standard of care for PDAC is surgery, chemotherapy, radiation, or a combination of these. Unfortunately, the five-year survival rate in PDAC patients is only 11.5% suggesting additional therapy strategies that target the tumor microenvironment may be needed. ML355 [Nbenzo[d]thiazol-2-yl)-4((2-hydroxy-3methoxybenzyl)-amino)benzenesulfonamide], an antithrombotic drug, and its more selective derivative, Lox12Slug001 [4-((2-hydroxy-3- methoxybenzyl)amino)-N- (naphtho[1,2-d]thiazol-2-yl)benzenesulfonamide], are potent 12-LOX inhibitors. These 12-LOX inhibitors would target the active site of 12-LOX, reducing 12-(S)- HETE levels. Through the loss of paracrine signaling, lower 12-(S)-HETE levels would decrease pancreatic cancer growth and decrease its resistance to chemo and radiation therapy. Using ELISA assays, our results show that 12-LOX inhibitors significantly decreased 12-(S)-HETE levels expressed in the aged fibroblasts with no significant effects on cell viability, death, and toxicity, indicating that these inhibitors are safe on normal cells. Using 2D co-culture of aged fibroblasts and FUCCI (Fluorescent Ubiquitination-based Cell Cycle Indicator) engineered MIA-PaCa-2 pancreatic cancer cells, we tested cancer cell proliferation and therapy response in the presence and absence of 12-LOX inhibitors. Our results showed that 12-LOX inhibitor significantly 2 decreased the growth index in the pancreatic cancer co-cultures treated with radiation, chemo, or combination. The growth index decline was associated with altered cell cycle progression in PDAC cells, indicating a G1 arrest and higher mitotic death. These results indicate that 12-LOX inhibitors are strong and promising adjuvant therapy targeting the pancreatic tumor microenvironment to improve clinical outcomes.
