Pancreatic cancer is a highly malignant cancer associated with high expression levels of sonic hedgehog signaling molecule (Shh), patched 1 (Ptch1), smoothened frizzled class receptor (Smo) and glioma-associated oncogene family zinc finger 1 (Gli1) in the hedgehog (Hh) signaling pathway.
Primary human PSCs and pancreatic cancer cell lines were exposed to SHH, cyclopamine, GLI family zinc finger-1 (Gli-1) small interfering RNA (siRNA), and Gremlin 1 siRNA to examine their associations and effects using an MTT assay, reverse transcription-quantitative polymerase chain reaction analysis, western blot analysis, and migration or invasion assays.
On the base of cDNA microarray data, we investigated regulating mechanism of Gli1 to some members of S100A genes family in pancreatic cancer cell lines firstly.
Immunohistochemistry showed that the expression of Gli1, MDM2 and p53 was much higher in 57 cases of PC than in paired normal pancreatic tissues, and was positively associated with tumour UICC stage and T stage (P < 0.05).
In vitro findings were supported using human clinical samples, where we showed an inverse correlation between αvβ6 and Gli1 expression in different BCC subtypes and pancreatic cancers.
Gli1 was expressed in SW1990 and CFPAC cells in which Smo was completely absent, as well as in PaTu8988, Panc-1 and BxPC-3 cells in which Smo was concomitantly present.
Moreover, we also demonstrate that the invasion of a pancreatic cancer and EMT resulting from the activation of SDF-1/CXCR4 axis is effectively inhibited by Smoothened (SMO) inhibitor cyclopamine and siRNA specific to Gli-1.
GLI2 (GLI-Kruppel family member 2), a zinc finger transcription factor that mediates Hedgehog signaling, is implicated in the progression of an ever-growing number of human malignancies, including prostate and pancreatic cancer, as well as basal cell carcinoma of the skin.
The inhibition of GLI-related protein expression with 1 or 2 was observed in HaCaT cells with exogenous GLI1, or human pancreatic cancer cells (PANC1), which express Hh/GLI components aberrantly.