Figure 6.

TRAIL-induced disruption of the mesothelial barrier promotes tumor cell invasion

(A–D) The invasion of primary OCMI tumor cell lines in collagen matrix through an HPMC monolayer was analyzed. Where indicated, the HPMC monolayer was pretreated with rh-TRAIL. (A) The loss of integrity of the HPMC monolayer was visualized by light microscopy and by fluorescence staining of caspase 3/7+ apoptotic HPMC and a representative picture is depicted. Trans-mesothelial invasion of OCMI tumor cells OC_58 (B and C) and OC_37 (D) was evaluated using fluorescence microscopy. The mean of invading cells was calculated for each experiment (n = 4–6 experiments using HPMC form different patients indicated by different colors) and is shown here relative to the untreated control with FCS as chemoattractant. (C) Representative fluorescent microscopic pictures of invaded tumor cells OCMI OC_58 are shown for untreated as well as rh-TRAIL-treated HPMC, both with and without FCS chemoattractant.

(E) Invasion of three primary OCMI tumor cell lines (OC-58: n = 4, blue dots; OC_37: n = 3, pink squares; OC_91: n = 3, orange triangles) through an HPMC monolayer pre-cultured with TAL (+/− α-CD3 Ab stimulation) to induce HPMC apoptosis.

The mean is shown by horizontal bars and vertical error bars represent the standard deviation in C–E. ∗ FDR <0.05; ∗∗ FDR <0.01; determined by paired t test and Benjamini-Hochberg adjustment (ns: not significant). Scale bars, 100μm.