BACKGROUND: The axon guidance gene family, SLIT/ROBO pathway, controls neural network formation, which correlates with the development of several cancers. METHODS: We found through analysis of the public database that ROBO4, one of the axon guidance molecules among the SLIT/ROBO family, is significantly downregulated in primary pancreatic cancer tissues compared with adjacent normal tissues. We carried out transfection experiments using three pancreatic cancer cell lines (MiaPaCa-2, BxPC-3, and SW1990) and one pancreatic duct epithelial cell line (HPDE6c7). A total of 51 clinical samples were then examined by immunohistochemical staining to find an association between ROBO4 expression at the protein level, clinical characteristics, and surgical outcomes. RESULTS: ROBO4 overexpression suppressed the invasion and migration abilities in MiaPaCa-2 and BxPC-3, while ROBO4 siRNA transfection to SW1990 and HPDE6c7 enhanced those activities. PCR-based profiling detected MMP-9 as a candidate downstream target of ROBO4, which was validated by decreased MMP-9 activity after the ROBO4 overexpression assay. High ROBO4 expression clinical samples had significantly better overall survival rather than low ROBO4 cases (P = 0.048). CONCLUSION: These findings suggest that decreased ROBO4 expression activates malignant phenotypes in cancer cells and is correlated with poor survival outcomes in pancreatic cancer.
BACKGROUND: The axon guidance gene family, SLIT/ROBO pathway, controls neural network formation, which correlates with the development of several cancers. METHODS: We found through analysis of the public database that ROBO4, one of the axon guidance molecules among the SLIT/ROBO family, is significantly downregulated in primary pancreatic cancer tissues compared with adjacent normal tissues. We carried out transfection experiments using three pancreatic cancer cell lines (MiaPaCa-2, BxPC-3, and SW1990) and one pancreatic duct epithelial cell line (HPDE6c7). A total of 51 clinical samples were then examined by immunohistochemical staining to find an association between ROBO4 expression at the protein level, clinical characteristics, and surgical outcomes. RESULTS: ROBO4 overexpression suppressed the invasion and migration abilities in MiaPaCa-2 and BxPC-3, while ROBO4 siRNA transfection to SW1990 and HPDE6c7 enhanced those activities. PCR-based profiling detected MMP-9 as a candidate downstream target of ROBO4, which was validated by decreased MMP-9 activity after the ROBO4 overexpression assay. High ROBO4 expression clinical samples had significantly better overall survival rather than low ROBO4 cases (P = 0.048). CONCLUSION: These findings suggest that decreased ROBO4 expression activates malignant phenotypes in cancer cells and is correlated with poor survival outcomes in pancreatic cancer.
Authors: Eric Thomas Domyan; Kelsey Branchfield; Daniel A Gibson; L A Naiche; Mark Lewandoski; Marc Tessier-Lavigne; Le Ma; Xin Sun Journal: Dev Cell Date: 2013-01-14 Impact factor: 12.270