e15784 Background: Pancreatic cancer is the second leading cause of death in tumor diseases worldwide. Neuropilin-1 (NRP1) is overexpressed in many tumors including the pancreatic cancer. The main goal is to reveal the role of NRP1 in the process of tumorigenesis. The expression of NRP1 and the presence of KRAS point mutation lead to the cell survival by lowering the SMAD2 phosphorylation. On the other hand, the NRP1 inactivation and the wild-type KRAS in tumor cells lead to the tumor growth inhibition. Our aim is to prove correlation between NRP1 level, SMAD2 and the mutational status of KRAS, NRAS in prognosis of patients with pancreatic cancer. Methods: Retrospective study is based on analysis of 50 FFPE bioptical samples (40 resections, 8 punctures, 2 thin-needle biopsies); histology verified all as adenocarcinomas. The expression level of NRP1 and SMAD2 is measured by Imunohistochemistry by mice monoclonal antibodies Anti-Neuropilin 1 and Anti-SMAD2 (Abcan) on the device BenchMark ULTRA (Ventana Medical Systems), Roche. DNA isolation is executed by QIAamp DNA Mini Kit. We used Codon Specific Mutation Detection Kit (Diatech pharmacogenetics) for detection of somatic point mutations in codons 12, 13, 61 and 146 of KRAS and NRAS genes. BRAF mutational status was revealed by direct sequencing on ABI Prism 3130. We monitor the level of expression of NRP1 and SMAD2 and correlate it to the mutational status of RAS and BRAF, and disease prognosis. Results: NRP1 expression was detected in 24 out of 50 cases, SMAD2 expression was detected in 13 of 50 cases, other cases without expression. KRAS gene mutation was detected in 8 cases out of 60, other cases of WT. Mutation in the NRAS gene was detected in 3 of 50 cases. BRAF gene mutation was detected in 1 case out of 50, other WT. NRP1 expression correlated with KRAS gene mutation status in 9 cases and a strong correlation (p = < 0.001) was recorded. One case of mutation in the BRAF gene correlated with KRAS mutation status and NRP1 expression. Due to the small number of samples tested, without statistical significance. Inactivation of NRP1 was detected in 15 cases and was confirmed by the WT status of the KRAS gene. Conclusions: Was demonstrated that causal relationship exists between inactive NRP1 and wild-type KRAS, and that these should cause decrease of the rate of tumor growth. These characteristics, which are achievable simultaneously during the histological verification, may serve as a potential prognostic marker for subsequent decision of how radical surgical resection should be.
Kras Gene Mutation and RASSF1A, FHIT and MGMT Gene Promoter Hypermethylation: Indicators of Tumor Staging and Metastasis in Adenocarcinomatous Sporadic Colorectal Cancer in Indian Population
