Project description:The host antitumor immunity changes drastically during carcinogenesis. Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is a precursor lesion of pancreatic cancer and progresses according to adenoma-carcinoma sequence. We found that the host antitumor immune reaction changes from an immune response to immune tolerance between intraductal papillary-mucinous adenoma (IPMA) and intraductal papillary-mucinous carcinoma (IPMC). In order to determine molecules affecting intraepithelial DC infiltration in IPMNs during multistep carcinogenesis, we examined the gene-expression profiles of entire transcripts of neoplastic cells at different stages. We collected normal and neoplastic epithelial cells from frozen tissue sections (normal main pancreatic duct, IPMA, IPMC, and invasive carcinoma originating in IPMN) by laser microdissection, extracted total RNA from them, and analyzed their gene expression profiles using Affymetrix microarrays.
Project description:The host antitumor immunity changes drastically during carcinogenesis. Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is a precursor lesion of pancreatic cancer and progresses according to adenoma-carcinoma sequence. We found that the host antitumor immune reaction changes from an immune response to immune tolerance between intraductal papillary-mucinous adenoma (IPMA) and intraductal papillary-mucinous carcinoma (IPMC). In order to determine molecules affecting intraepithelial DC infiltration in IPMNs during multistep carcinogenesis, we examined the gene-expression profiles of entire transcripts of neoplastic cells at different stages.
Project description:Regulatory T cells (Treg) are common in the tumor microenvironment in both human pancreatic cancer and in genetically engineered mouse models of the disease. Previous studies in orthotopic syngeneic models of pancreatic cancer -recapitulated in our own data- indicated that Treg depletion results CD8+ T cell-mediated tumor regression. In human patients and in mouse models, regulatory T cells accumulate during the onset of Pancreatic Intraepithelial Neoplasia (PanIN), the earliest steps of carcinogenesis. We thus generated a genetic model to investigate the role of regulatory T cells during the onset of pancreatic carcinogenesis. Unexpectedly, depletion of Tregs during early stages of carcinogenesis led to accelerated tumor progression.
Project description:Regulatory T cells (Treg) are common in the tumor microenvironment in both human pancreatic cancer and in genetically engineered mouse models of the disease. Previous studies in orthotopic syngeneic models of pancreatic cancer -recapitulated in our own data- indicated that Treg depletion results CD8+ T cell-mediated tumor regression. In human patients and in mouse models, regulatory T cells accumulate during the onset of Pancreatic Intraepithelial Neoplasia (PanIN), the earliest steps of carcinogenesis. We thus generated a genetic model to investigate the role of regulatory T cells during the onset of pancreatic carcinogenesis. Unexpectedly, depletion of Tregs during early stages of carcinogenesis led to accelerated tumor progression.
Project description:CD24 is a potential oncogene reported to be overexpressed in a large variety of human malignancies. We have shown that CD24 is overexpressed in 90% of colorectal tumors at a fairly early stage in the multistep process of carcinogenesis. Anti-CD24 monoclonal antibodies (mAb) induce a significant growth inhibition in colorectal and pancreatic cancer cell lines that express the protein. This study is designed to investigate further the effects of CD24 down-regulation using mAb or small interfering RNA in vitro and in vivo. Western blot analysis showed that anti-CD24 mAb induced CD24 protein down-regulation through lysosomal degradation. mAb augmented growth inhibition in combination with five classic chemotherapies. Xenograft models in vivo showed that tumor growth was significantly reduced in mAb-treated mice. Similarly, stable growth inhibition of cancer cell lines was achieved by down-regulation of CD24 expression using short hairpin RNA (shRNA). The produced clones proliferated more slowly, reached lower saturation densities, and showed impaired motility. Most importantly, down-regulation of CD24 retarded tumorigenicity of human cancer cell lines in nude mice. Microarray analysis revealed a similar pattern of gene expression alterations when cells were subjected to anti-CD24 mAb or shRNA. Genes in the Ras pathway, mitogenactivated protein kinase, or BCL-2 family and others of oncogenic association were frequently down-regulated. As a putative new oncogene that is overexpressed in gastrointestinal malignancies early in the carcinogenesis process, CD24 is a potential target for early intervention in the prevention and treatment of cancer. The study compared gene expression profiles between human CRC cells HT29 before and after expression of 1 and 2 shRNA vectors directed at the human CD24 gene, GFP control gene, HT29 cells and Colo357, human pancreatic cancer cells, before and after the inhibition of the CD24 molecule using 72h treatment with anti-CD24 monoclonal antibodies.
Project description:The development of oral squamous cell carcinoma (OSCC) is a multistep process requiring the accumulation of genetic alterations. Oral carcinogenesis is a multifactorial process involving numerous genetic changes that affect the activity of oncogenes, tumor suppressor genes and other classes of disease-related genes.Therefore, to identify the responsive genes for progression of oral dysplasia or OSCC, we here performed CGH analysis to DNA from oral dysplasia and OSCC by microdissection