Interactions between human colon carcinoma cells, fibroblasts and monocytic cells in coculture--regulation of cathepsin B expression and invasiveness.
To elucidate the importance of the tumor/host interaction in malignant tumors, we investigated the colon carcinoma cell line HT-29 in coculture with monocytic cells (THP-1) and fibroblasts (175BR) for cathepsin B expression and activity. The tumor cells were grown in monolayer cultures or as multicellular tumor spheroids. After coculture, the three cell types were separated by labeled magnetic beads for cathepsin B mRNA and protein analysis. The invasive potential was studied in in vitro invasion assays. The expression level of cathepsin B was found to be 10-fold increased in three dimensional spheroids of HT-29 compared to HT-29 monolayers. The coculture of HT-29 with THP-1 cells and/or human fibroblasts led to a considerable increase in cathepsin B mRNA expression in both tumor and tumor-associated cells. The invasive potential of the tumor cells was 5 times increased by adding monocytic cells to the assay system. This is dependent on the functional activity of cathepsin B as shown by specific siRNA's and seems to be regulated by activation of ERK1/2 and p38 signal transduction pathways.
Krueger
Sabine
S
Department of Pathology, Otto-von-Guericke University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany. sabine.krueger@medizin.uni-magdeburg.de
Kalinski
Thomas
T
Wolf
Hella
H
Kellner
Udo
U
Roessner
Albert
A
D002277:Carcinoma / Q000473:pathology*; D002401:Cathepsin B / Q000096:biosynthesis*; D002450:Cell Communication; D003110:Colonic Neoplasms / Q000473:pathology*; D005347:Fibroblasts / Q000502:physiology; D005786:Gene Expression Regulation; D006801:Humans; D048052:Mitogen-Activated Protein Kinase 3; D009000:Monocytes / Q000502:physiology; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology
D012333:RNA, Messenger; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D002401:Cathepsin B