Initial formation of IGROV1 ovarian cancer multicellular aggregates involves vitronectin

Abstract

Ovarian cancer progression is frequently associated with the development of malignant ascites. Multicellular aggregates of carcinoma cells (spheroids) found within ascites are thought to be able to promote peritoneal carcinomatosis. We have previously demonstrated the involvement of the vitronectin/alphav integrin adhesive system in the dissemination of ovarian cancer cells and continue to investigate the influence of these molecules by studying their role(s) in spheroid behavior. The aim of this study was to generate ovarian cancer multicellular aggregates and to focus on the role of vitronectin and alphav integrins in their initiation. IGROV1 cancer cells cultured in the absence of adhesive substratum formed multicellular aggregates comparable to spheroids. After 21 days, a fraction of the cells within clusters remained viable and proliferated recurrently. Within the multicellular aggregates, vitronectin and alphav integrins were co-localized at intercellular sites, suggesting their involvement in cell-cell interactions. Initial formation of IGROV1 aggregates was inhibited using anti-vitronectin and anti-alphav integrin blocking antibodies or the cyclic peptide cRGDfV. Vitronectin expression persisted during cluster disaggregation on fibronectin. These results demonstrate the ability of IGROV1 cells to generate multicellular aggregates and point to a contributory role for the vitronectin/alphav integrin system in the initial step of this process. These events could represent a prerequisite for further dissemination.

Progress in melanoma modelling in vitro

“…MCTS can also be formed using a synthetic cyclic RGD (Arg‐Gly‐Asp) peptide, called cyclo‐RGDfK(TPP). The RDG‐motif, present in several ECM proteins, is responsible for binding to integrins, thus providing cell‐to‐cell and cell‐to‐matrix interaction . Akasov and co‐workers were able to induce the cell self‐assembly of both normal and tumor cells by adding the cyclic RGDfK and the cyclo‐RGDfK(TTP) directly to the monolayer cultures obtaining spheroids that were homogenous in size and useful to evaluate the cytotoxic effect of antitumor drugs .…”

“…The RDG-motif, present in several ECM proteins, is responsible for binding to integrins, thus providing cell-to-cell and cell-to-matrix interaction. [46] Akasov and co-workers were able to induce the cell self-assembly of both normal and tumor cells by adding the cyclic RGDfK and the cyclo-RGDfK(TTP) directly to the monolayer cultures obtaining spheroids that were homogenous in size and useful to evaluate the cytotoxic effect of antitumor drugs. [47] The scaffold-based method consists in the use of a porous 3D scaffold which physically supports cell aggregation, allowing the formation of MCTS with a controlled size.…”

Vitronectin in Vascular Context: Facets of a Multitalented Matricellular Protein

“…101,146,147 VN is found in association with a variety of (human) tumors, may induce cancer stem cell differentiation by downregulation of stem cell genes through avß3 integrin-mediated mechanisms, 148 and seems to influence cell adhesion and motility as well as formation of cancer cell aggregates. 149 Based on expression studies, biosynthesis of VN was documented in cancer cell lines derived from the cervix, lung, pancreas, and ovary as well as in stromal cells, disclosing its distribution along the cell surface and within thin deposits at the cell periphery. [150][151][152] The detection of VN in association with ovarian tumors but also with normal human ovarian epithelial cells, from which most of ovarian cancers originate, 153 led to a proposed role for the VN-avß3integrin system in adhesion and proliferation of these cells.…”

Hydrogel Microwell Arrays Allow the Assessment of Protease-Associated Enhancement of Cancer Cell Aggregation and Survival

“…This high variability in aggregate size is also reflected in in vitro aggregate cultures applying the liquid overlay technique [35,48,57,58] or hanging droplet method [46,59] using different ovarian cancer cell lines [34]. In order to control the cellular microenvironment of hydrogel microwell arrays, photolithography was used to fabricate microwells of varying sizes (50 × 50, 100 × 100, 150 × 150, 200 × 200 µm) to generate aggregates of different sizes (Figure 3(A), top panel).…”