Flow induces epithelial-mesenchymal transition, cellular heterogeneity and biomarker modulation in 3D ovarian cancer nodules

Abstract

Seventy-five percent of patients with epithelial ovarian cancer present with advanced-stage disease that is extensively disseminated intraperitoneally and prognosticates the poorest outcomes. Primarily metastatic within the abdominal cavity, ovarian carcinomas initially spread to adjacent organs by direct extension and then disseminate via the transcoelomic route to distant sites. Natural fluidic streams of malignant ascites triggered by physiological factors, including gravity and negative subdiaphragmatic pressure, carry metastatic cells throughout the peritoneum. We investigated the role of fluidic forces as modulators of metastatic cancer biology in a customizable microfluidic platform using 3D ovarian cancer nodules. Changes in the morphological, genetic, and protein profiles of biomarkers associated with aggressive disease were evaluated in the 3D cultures grown under controlled and continuous laminar flow. A modulation of biomarker expression and tumor morphology consistent with increased epithelial-mesenchymal transition, a critical step in metastatic progression and an indicator of aggressive disease, is observed because of hydrodynamic forces. The increase in epithelial-mesenchymal transition is driven in part by a posttranslational up-regulation of epidermal growth factor receptor (EGFR) expression and activation, which is associated with the worst prognosis in ovarian cancer. A flowinduced, transcriptionally regulated decrease in E-cadherin protein expression and a simultaneous increase in vimentin is observed, indicating increased metastatic potential. These findings demonstrate that fluidic streams induce a motile and aggressive tumor phenotype. The microfluidic platform developed here potentially provides a flow-informed framework complementary to conventional mechanism-based therapeutic strategies, with broad applicability to other lethal malignancies.tumor microenvironment | stress response | molecular targets | combination therapies | photodynamic therapy C ancer metastases are responsible for 90% of cancer-related deaths, but the biological and physical factors that determine the fate and heterogeneity of metastatic tumors remain poorly understood (1-6). Ovarian cancer is the leading cause of deaths related to gynecologic malignancies, and is frequently diagnosed at an advanced stage. Initially, ovarian cancer metastasizes by direct extension to sites that are proximal to the primary tumor through a complex series of events including migration, assembly, and proliferation (7-10). Dissemination to distant sites prognosticates the poorest outcomes for ovarian cancer patients and occurs via transcoelomic, lymphatic, or hematogenous routes (7,9,10). Among these routes, transcoelomic metastases are the most frequent and are responsible for the highest morbidity and mortality rates, which in turn are associated with the frequent production of malignant ascites (7, 9, 10). Under normal physiologic conditions, the great majority of peritoneal fluid is resorbed by the vasculature and the lymphatics and...

Review: Mechanotransduction in ovarian cancer: Shearing into the unknown

“…The ascitic fluid flow is triggered by gravity, changes in diaphragmatic pressure from breathing, surrounding organ movement aiding digestion, and bodily movements like walking. 31 The continuous barrage of turbulent fluid flow stimulates a variety of mechanotransduction signaling pathways and further exfoliates ovarian tumor cells and cellular aggregates from the ovarian surface epithelium into the peritoneal cavity. After their escape into the ascites, these free-floating cancer cells and cellular clusters often self-assemble and aggregate to form spheroids, thereby overcoming anoikis.…”

“…25,32 Once ovarian cancer cells have disseminated within the ascites, they have access to the most common metastatic sites of ovarian cancers: the peritoneum, the greater omentum, the right subphrenic region, the lung, and the liver. [31][32][33] The presence of ascites and forces associated with them facilitate transcoelomic metastasis, the most common form of ovarian cancer metastasis. 28,31 Figure 1 details the mechanical forces relevant to ovarian cancers, the ascitic buildup, and the transcoelomic metastatic process in ovarian cancers.…”

“…[31][32][33] The presence of ascites and forces associated with them facilitate transcoelomic metastasis, the most common form of ovarian cancer metastasis. 28,31 Figure 1 details the mechanical forces relevant to ovarian cancers, the ascitic buildup, and the transcoelomic metastatic process in ovarian cancers.…”

“…It has been predicted that shear stress values within ascites are low, with relatively little to no support in either experimental or mathematical modeling. 29,31,45 Computer simulated models are required to improve our understanding of the physiological stresses that occur within the peritoneal cavity. A diseased patient's musculoskeletal/organ movements cause a change in the shape of the peritoneal cavity which in turn causes fluid movement within the ascites.…”

“…Molecular changes associated with the metastatic cascade due to continuous shear force was investigated within a microfluidic device designed by Rizvi et al 31 [ Fig. 2(b)].…”