Figure 1.

Mesothelioma CSF-1R^pos cells exist in vivo. (a) Box plot showing the levels of CSF-1R mRNA in matched peritoneal versus mesothelioma samples from Affymetrix microarray. (b, inset) Representative FACS dot plots of two mesothelioma primary cultures stained with anti-CSF-1R antibody (right) and an isotype-matched antibody (left) (as a control) at day 75. Gated positive cells are in red. (Main) Histograms showing the percentage of CSF-1R^pos cells in seven mesothelioma primary cultures stained with an anti-CSF-1R antibody (right) or the isotype-matched antibody (left) at the indicated times after harvesting. Note that no decrease in the number of CSF-1R^pos cells was observed after long-term culturing of the primary specimens. (c) The primary CSF-1R^pos cells are of mesothelial origin. (Upper panel) Representative FACS dot plots of the meso no. 5 primary cells assayed for CSF-1R and CALRETININ expression at days 3 and 75 after seeding, respectively. (Lower panel) Histograms showing the average percentage of Calretinin^pos and low/neg cells in the CSF-1R^pos fraction of the same mesothelioma primary cultures at 60–90 days after seeding (average time: 70 days). (d) Histograms show the levels of CSF-1 and IL-34 in the conditioned media of the indicated primary MPM cultures, as assessed by ELISA assay at day 60 of culture. Fresh cell growth medium was used as a background control. Bars indicate mean values±S.E.M. of at least two independent experiments