Expression profiles of a human pancreatic cancer cell line upon induction of apoptosis search for modulators in cancer therapy.

We analyzed the differential gene expression in the pancreatic cancer cell line NP-18 upon induction of apoptosis caused by cyclin-dependent kinase inhibition triggered by either overexpression of the tumor suppressor gene p16(INK4A)using an adenoviral construction or incubation with the chemical inhibitors, roscovitine or olomoucine. Screening was performed using cDNA arrays from Clontech that allowed the determination of the expression of 1,176 genes specifically related with cancer. The analysis was carried out using the Atlas Image 2.01 (Clontech) and GeneSpring 4.2 (Silicon Genetics) softwares. Among the differentially expressed genes, we chose for further validation histone deacetylase 1 (HDAC1), von Hippel Lindau and decorin as upregulated genes, and Sp1, hypoxia-inducible factor-1 alpha and DNA primase as downregulated genes. The changes in the expression of these genes to mRNA were validated by quantitative RT-PCR and the final translation into protein by Western blot analysis. Inhibition of HDAC activity, Sp1 binding and DNA primase expression led to an increase in the level of apoptosis, both in parental cells and in doxorubicin-resistant cells. Therefore, these proteins could constitute possible targets to develop modulators in cancer chemotherapy that would increase or restore apoptosis.