Blocking of the CB3-region reduces growth dose dependently (? indicates p 0.05 compared to index 1.0 and *indicates p 0.05 compared to 0.1 g/cm2). expression pattern of integrin receptors and type IV collagen in normal pancreas tissue shown as single channels. The same pictures as in Figure?1B but the different channels are presented individually and not merged. 1471-2407-13-154-S2.ps (17M) GUID:?8C105B79-5224-4219-8D04-1F42E4757753 Additional file 3: Figure S3 Expression pattern of integrin receptors and type IV collagen in pancreatic cancer tissue shown as single channels. The same pictures as in the inserts (x100 magnification) of Figure?2B and Figure?2C, but the different channels are presented individually and not merged. A represents well differentiated and B moderately differentiated pancreatic adenocarcinoma. 1471-2407-13-154-S3.ps (19M) GUID:?A510A05B-2EC6-4D2F-AA81-7B1D8BCC8DB2 Additional file 4: Figure S4 Expression of integrin receptors in pancreatic cancer cell lines shown as single channels. The same pictures as Figure?3 but the different channels are presented individually and not merged. 1471-2407-13-154-S4.ps (18M) GUID:?072E9945-0C71-4573-843B-9625D841D505 Additional file 5: Movie S1 Difference in migration for 1- and control-transfected cells. Movie that illustrates the difference in migratory capacity between 1(IV)-siRNA transfected and control-siRNA transfected cells. 1471-2407-13-154-S5.mov (6.4M) GUID:?D784E274-1A92-4D4F-8F65-CE0CC585F572 Abstract Background Pancreatic cancer shows a highly aggressive and infiltrative growth pattern and is characterized by an abundant tumor stroma known to interact with the cancer cells, and to influence tumor growth and drug resistance. Cancer cells actively take part in the production of extracellular matrix proteins, which then become deposited into the tumor stroma. Type IV collagen, an important component of the basement membrane, is highly expressed by pancreatic cancer cells both and in human pancreatic cancer tissue. The cellular effects of type IV collagen were studied in pancreatic cancer cell lines by reducing type IV collagen expression through RNA interference and by functional receptor blocking of integrins and their binding-sites on the type IV collagen molecule. Results We show that type IV collagen is expressed close to the cancer cells and (Figure?3 and Additional file 4: Figure S4) and colocalizes with integrin 2 and 1. Integrin 1 is mostly found intracellular and less at the cell surface. Open in a separate window Figure 3 Expression of integrin receptors in pancreatic cancer cell lines. Merged images with type IV collagen in red and integrin Metaxalone receptors in green. Type IV collagen is highly expressed by pancreatic cancer cells. Integrin 1 is expressed, but is found also intracellularly, not exclusively at the cell surface. Rabbit Polyclonal to MRPL32 Integrin 2 and 1 are expressed and partly colocalized with type IV collagen (in yellow). Cell nuclei are stained by DAPI (in blue). In the figure HPAC cells are shown, but similar expression pattern was seen with CPFAC-1. Both type I Metaxalone and type IV collagens promote growth and migration and inhibit apoptosis, but are expressed in different stromal compartments In pancreatic cancer type I collagen is predominantly expressed in the desmoplastic reaction that surrounds and infiltrates clusters of cancer cells (Figure?4A). However, most of the cancer cells are not in direct contact with type I collagen. Type IV collagen, on the other hand, is highly expressed in close relation to all cancer cells. Open in a separate window Figure 4 Expression patterns of type I and type IV collagen and their effect on cell growth. A. Double staining of type I (in green) and type IV collagen (in red) in a pancreatic adenocarcinoma. Cell nuclei are stained by DAPI (in blue). Type I collagen is predominantly found in the desmoplastic reaction (D) that surrounds and partly infiltrates clusters of tumor cells (T). Type IV collagen is highly expressed in close Metaxalone proximity to the tumor cells with lower expression in the desmoplastic area. Magnification x40. B. Growth of pancreatic cancer cells on different matrices after 2?days of incubation. Both type I and type IV collagens promote growth when compared to BSA (used as control protein) in all different coating concentrations (p? ?0.05). C. Apoptosis measured with the M30-Apoptosense? ELISA after 48?h incubation in serum free conditions with cells grown on different matrices. Type IV collagen inhibits induction of apoptosis compared to a control BSA matrix (* indicates Metaxalone p? ?0.05 compared to BSA). D. Time for wound-healing closure for cells grown on different matrices (coated with 0.5 g/cm2). * indicates p? ?0.05 compared to BSA. Picture-inserts represent the size of the wound at 445?minutes, when the wound on the type I collagen matrix was closed (dotted line indicates cell front). Figures B, C, and D are all based on data from HPAC, but similar results were observed for CFPAC-1. Pancreatic cancer cells were grown on both type I or type IV collagen matrices, and both types of collagen.