Fig. 1

EOC peritoneal metastasis biopsies show HDAC1 increased expression in MC-derived CAFs and HDAC1–2 inhibition limits mesenchymal-like MCs/EOC adhesive interactions. A left, serial sections of a control peritoneum show a conserved MC monolayer negative for HDAC1 and HDAC2. Insets show a higher magnification of the delimited areas. A Middle, serial sections of a sub-mesothelial compact zone in an EOC patient with peritoneal metastasis show areas of Podoplanin (PDPN), Fibroblast Activation Protein (FAP) and nuclear HDAC1 and HDAC2 co-localization. Right, Representative images of PDPN and FAP staining of spindle-like cells surrounding deep tumor nodules. Nuclear HDAC1 and HDAC2 staining overlap with areas of accumulation of MC-derived CAFs. Tumor cells are also HDAC1 and HDAC2 positive. Scale bar: 100 μm; CAFs: carcinoma-associated fibroblasts; T: tumor. B Representative images of GFP-labelled SKOV3 cells adhering to primary MC monolayers; C GFP-SKOV3 cells adhering to MeT5A cell monolayers; D GFP-OVCAR-3 cells adhering to MeT5A cells monolayers; E PHK26-stained Kuramochi cells adhering to MeT5A cells monolayers. Nuclei are stained with DAPI (blue). CTR: control treatment. MeT5A cells monolayers were at 100% confluence at the time of the experiment. Scale bar: 25 μm. Quantifications are shown at the right of each figure. MeT5A cells were pretreated with TGFβ1 in combination with IL-1β (T + I), and treated or not with MS-275 (250 nM) for 72 hours. Results are shown as relative number of adherent SKOV3 cells. 3 fields for each sample were analyzed. F Images of GFP-SKOV3 cells adhesion to MeT5A cells were acquired with a spinning disk automated confocal microscope and analyzed using Columbus (TM) platform considering relative tumor cells number. Results are shown as percentage of attached GFP-SKOV3 cells out of total seeded cells. G qRT-PCR showing genetic silencing of HDAC1, HDAC2 alone and HDAC1 in combination with HDAC2 from total RNA of MeT5A cells used for the experiment shown in H. Bars represent means±SEM of 3 experiments. H Adhesion assay showing adhesion of GFP-labelled SKOV3 cells to siHDAC1, siHDAC2 and siHDAC1-HDAC2 MeT5A cells. Representative images are shown on the left. Scale bar: 10 μm. Quantification of the experiment is shown on the right. Each experiment was performed at least 3 times in triplicate. Differences were considered significant at P < 0.05 (*p < 0.05; **p < 0.01; ***p < 0.001)