Abstract B16: Prognostic evaluation of components associated with epithelium-mesenchymal transition in women with serous carcinoma of high ovary grade

Abstract

Abstract Introduction: High-grade serous ovarian carcinoma (HGSOC) is a heterogeneous disease with high mortality. Initially most women respond to platinum chemotherapy, but rapidly many become resistant to the drug and progress to relapse and death. Better knowledge of the pathways responsible for the mechanisms of invasion and metastasis in women with HGSOC may help in the identification of prognostic biomarkers and in the development of new target therapies. The epithelial-mesenchymal transition (EMT) is an important cellular process related to invasion and metastasis. Some protein components such as the receptor tyrosine kinase, discoidin domain receptor 2 (DDR2), acting on the signal-regulated kinase 1/2 (ERK1/2) extracellular pathway, and the transcriptional co-activator yes-associated protein (YAP), acting in Hippo, are associated with EMT. In such pathways, microRNAs, such as miR-182, miR-96, and miR-9 are described as post-transcriptional regulators. Objective: To evaluate the expression of DDR2, YAP and miR-182, miR-96 and miR-9 in formalin-fixed, paraffin-embedded blocks with HGSOC, and its association with clinical, tumor, platinum response, and survival characteristics. Methods: 63 women with HGSOC stages III and IV, who underwent platinum chemotherapy from 1996 until 2013, followed up until 2016 at the Women's Hospital Prof. Dr. José Aristodemo Pinotti, Brazil, were included. All women had paraffin blocks and complete clinical data on the chart. DDR2 and YAP expression were assessed by immunohistochemistry on tissue microarray (TMA) slides and the microRNAs were evaluated by real-time polymerase chain reaction (rtPCR). For the comparison of DDR2 and YAP expression with age, CA125 serum level, post-surgery residual stage disease, and platinum response, Mann-Whitney and Fisher tests were used. Progression-free survival (PFS) and overall survival (OS) were calculated by Cox regression. The PFS and OS curves were estimated by the Kaplan-Meier method and compared by the Log-Rank test. Expression of miR and DDR2 and YAP levels were compared by the t-test. Results: DDR2 expression was high in 8 (13.7%) women. There was no association between DDR2 expression and age, stage, CA125, residual post-surgery disease, and response to platinum-based chemotherapy. PFS was significantly worse in women whose tumors had high DDR2 expression (p=0.03), but not OS (p=0.49). MiR-182 level expression was lower in the group with high DDR2 expression (p<0.001), but not the expression level of miR-96 (p=0.067). High nuclear expression of YAP with low cytoplasmic expression was found in 15 (24.5%) women. There was no association between the expression of YAP and the characteristics of the disease or evolution of the women. MiR-9 level expression was not associated with YAP expression. Conclusions: Low levels of miR-182 expression were associated with high expression of DDR2, which was associated with poorer DFS. These findings suggest that the ERK1/2 signaling pathway was relevant to the EMT of these HGSOCs. The role of Hippo remained indeterminate. Citation Format: Susana Oliveira Ramalho, Luis Otávio Sarian, Rodrigo Natal, Liliana Andrade, Amanda Ferracini, Marina Pavanello, Cassio Cardoso Filho, Sophie Derchain. Prognostic evaluation of components associated with epithelium-mesenchymal transition in women with serous carcinoma of high ovary grade [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B16.