Abstract 5023: PFKP contributes to ovarian cancer metastasis, stemness and anchorage-independent growth via α5 integrin and ERK/MMP9 signaling
Authors: Zhang Ruiqian , Siu Michelle K.Y. , Mo Xuetang , Yung Mingo M.H. , Wang Jingjing , Jiang Yuxin , Cheung Annie N.Y. , Ngan Hextan Y.S. , Chan Karen K.L. 
Published: April 2023

Abstract
Background: Ovarian cancer is one of the most aggressive malignancies threatening women’s health worldwide. Its high mortality rate is largely due to symptoms not appearing until late in the disease, usually after the cancer has metastasized. Despite current state-of-the-art treatments, the prognosis for patients remains poor. New effective treatments are urgently needed to improve patient survival. High lactate production and low glucose oxidation, independent of oxygen availability, is known as the Warburg effect and is common in cancer. Phosphofructokinase 1 (PFK-1) irreversibly converts fructose 6-phosphate to fructose 1,6-bisphosphate, the first step in the Warburg effect. The platelet isoform of PFK (PFKP) regulates glycolysis and plays roles in tumorigenesis in other human cancers, the precise mechanisms has yet to be defined. Moreover, PFKP in ovarian cancer remain unknown. We hypothesize that PFKP modulates metastasis and stemness in ovarian cancer.
Methods: Expression of PFKP in clinical samples, ascites-derived tumor cells, normal ovarian epithelial cells (HOSEs) and ovarian cancer cell lines was determined by immunohistochemistry/immunofluorescence and qPCR/immunoblotting, respectively. The correlation between PFKP and clinicopathological parameters was analyzed. Ectopic expression or knockdown of PFKP followed by migration, invasion, sphere formation and soft agar assays were performed in ascites-derived tumor cells and ovarian cancer cell lines to investigate the effects on metastasis, stemness and malignant transformation respectively. Additionally, the related signaling pathway was explored by qPCR and immuoblotting.
Results: Up-regulation of PFKP in clinical samples, ascites-derived tumor cells and ovarian cancer cell lines was found when compared to HOSEs. Higher PFKP was correlated to shorter overall and disease-free survival. Functionally, knockdown of PFKP by siRNA/shRNA approaches in ascites-derived tumor cells, ES-2 and HeyA8 cells decreased migration, invasion, sphere formation and colony formation in soft agar, which was accompanied by decreased expression α5 integrin, pERK and MMP9. Ectopic expression of PFKP in SKOV-3 cells showed opposite effects. Intriguingly, we found that MEK-1 inhibitor (U0126) or an anti-MMP9 neutralizing antibody could block PFKP-mediated migration/sphere formation abilities.
Conclusion: PFKP was overexpressed in ovarian cancer and regulates metastasis, stemness and anchorage-independent growth. α5 integrin and ERK/MMP9 signaling were involved in such functional effects. PFKP could be a potential prognostic marker and therapeutic target for ovarian cancer.
Citation Format: Ruiqian Zhang, Michelle K.Y. Siu, Xuetang Mo, Mingo M.H. Yung, Jingjing Wang, Yuxin Jiang, Annie N.Y. Cheung, Hextan Y.S. Ngan, Karen K.L. Chan. PFKP contributes to ovarian cancer metastasis, stemness and anchorage-independent growth via α5 integrin and ERK/MMP9 signaling. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5023.