Biomedical subjects

Harry S Cooper

Publications and source records attributed to Harry S Cooper.

5 recordsLinked to original sources

PubMed2005

Generation of a unique strain of multiple intestinal neoplasia (Apc(+/Min-FCCC)) mice with significantly increased numbers of colorectal adenomas.

The relevance of the Apc(+/Min) mouse model in the study of human colorectal cancer remains uncertain due to the predominance of small intestinal adenomas and few, if any, colorectal adenomas. A new strain of Apc(+/Min) mice (Apc(+/Min-FCCC)) with significantly greater numbers of colorectal adenomas has been generated and characterized. Male C57BL/6J-Apc(+/Min) mice (the Jackson Laboratory, Bar Harbor, ME) were crossed with wild-type (Apc(+/+)) C57BL/6J females from an independent colony at this institution (offspring=Apc(+/Min-FCCC)) and 233 animals were evaluated over 20 generations. In order to determine the contribution of genetics to the enhanced colorectal adenoma phenotype, breeding pairs (Apc(+/Min) male x wild type female C57BL/6J) were purchased from the Jackson Laboratory and offspring (Apc(+/Min-JAX)) were maintained in our facility under identical conditions (n=98). Animals were fed Purina Rodent chow (#5013) diet containing 5% fat. The entire intestinal tract was examined histopathologically in both strains. Both the Apc and Pla2g2a (candidate for Mom1) genes were sequenced and found to be identical for both the Apc(+/Min-FCCC) and Apc(+/Min-JAX) mouse strains. The multiplicity of colorectal adenomas in the Apc(+/Min-FCCC) mice was much higher than reported in the literature and significantly greater than the multiplicity of colorectal adenomas in Apc(+/Min-JAX) mice maintained in our facility (P=0.01). Apc(+/Min-FCCC) had a significantly greater incidence of rectal prolapse (P = 0.02) and small intestinal adenocarcinomes (P=0.001), and multiplicity of small intestinal adenocarcinomas (P=0.001) compared to Apc(+/Min-JAX) mice. Male Apc(+/Min-FCCC) mice had significantly greater numbers of colorectal adenomas compared to female Apc(+/Min-FCCC) mice (P=0.0002), as did male Apc(+/Min-JAX) mice vs. female Apc(+/Min-JAX) mice (P< 0.0001). These results allow us to conclude: (1) Apc(+/Min-FCCC) mice are unique in that they develop significantly greater numbers of colorectal adenomas and small intestinal cancers, and a significantly greater incidence of small intestinal cancers and rectal prolapse than Apc(+/Min-JAX) mice. (2) This study represents the first report of a significant gender difference in multiplicity of colorectal adenomas. (3) Differences between Apc(+/Min-FCCC) and Apc(+/Min-JAX) mice in currently undefined genetic modifiers may contribute to the enhanced colorectal phenotype. (4) The Apc(+/Min-FCCC) strain is highly suited for the investigation of colorectal neoplastic disease and chemoprevention studies.

Adenoma↗

PubMed2005

Sulindac sulfone is most effective in modulating beta-catenin-mediated transcription in cells with mutant APC.

Sulindac sulfone (FGN-1, Aptosyn), a metabolite of the nonsteroidal anti-inflammatory drug sulindac, lacks cyclooxygenase inhibitory activity. Although its ability to inhibit tumorigenesis in both carcinogen-treated animals and patients with familial adenomatous polyposis has been attributed to the induction of apoptosis, its complete mechanism of action remains unclear. The purpose of the present study was to determine the ability of sulindac metabolites to regulate cellular levels of beta-catenin and downstream targets of the adenomatous polyposis coli (APC)/beta-catenin pathway in vitro. Sulindac sulfone was consistently more potent than the sulfide metabolite in all analyses, significantly decreasing the expression of total cellular beta-catenin (50% of control), pro-caspase 3 (49%), cyclin D1 (51%), and PPARdelta (65%) in SW480 cells. No significant alteration in pro-caspase 3 or beta-catenin expression was found in HCA7, LS174, or Caco-2 cells treated with sulindac sulfone. A dose-dependent reduction in TCF-mediated transcriptional activity was also observed in SW480 cells. These data demonstrate that sulindac sulfone can modulate the APC/beta-catenin pathway in vitro and that its efficacy is dependent upon the mutational status of APC and beta-catenin.

Adenomatous Polyposis Coli Protein↗

PubMed2004

Loss of methylthioadenosine phosphorylase and elevated ornithine decarboxylase is common in pancreatic cancer.

PURPOSE: Loss of the methylthioadenosine phosphorylase (MTAP) gene at 9p21 is observed frequently in a variety of human cancers. We have shown previously that MTAP can act as a tumor suppressor gene and that its tumor suppressor function is related to its effect on polyamine homeostasis. Ornithine decarboxylase is a key enzyme in the regulation of polyamine metabolism. The aim of this study is to analyze MTAP and ornithine decarboxylase (ODC) expression in primary pancreatic tumor specimens. EXPERIMENTAL DESIGN: We measured MTAP and ODC activity in protein extracts derived from 30 surgically resected tumor samples and eight normal pancreas samples. In a subset of six samples, we also examined MTAP DNA using interphase fluorescence in situ hybridization. In addition, we examined the effect of the ODC inhibitor difluoromethylornithine on two pancreatic adenocarcinoma-derived cell lines. RESULT: MTAP activity was 2.8-fold reduced in adenocarcinomas and 6.3-fold reduced in neuroendocrine tumors compared with control pancreas. Conversely, ODC activity was 3.6-fold elevated in adenocarcinomas and 3.9-fold elevated in neuroendocrine tumors compared with control pancreas. Using interphase fluorescence in situ hybridization, we found in tumor samples that 43 to 75% of the nuclei had lost at least one copy of MTAP locus, indicating that loss of MTAP activity was at least partially because of deletion of the MTAP locus. We also show that inhibition of ODC by difluoromethylornithine caused decreased cell growth and increased apoptosis in two MTAP-deleted pancreatic adenocarcinoma-derived cell lines. CONCLUSIONS: MTAP activity is frequently lost, and ODC activity is frequently elevated in both pancreatic adenocarcinoma and neuroendocrine tumors. Inhibition of ODC activity caused decreased cell growth and increased apoptosis in pancreatic tumor-derived cell lines. These findings suggest that MTAP and polyamine metabolism could be potential therapeutic targets in the treatment of pancreatic cancer.

Adenocarcinoma↗

PubMed2004

Optimized procedures for microarray analysis of histological specimens processed by laser capture microdissection.

Analysis of cell-specific gene expression patterns using microarrays can reveal genes that are differentially expressed in diseased and normal tissue, as well as identify genes associated with specialized cellular functions. However, the cellular heterogeneity of the tissues precludes the resolution of expression profiles of specific cell types. While laser capture microdissection (LCM) can be used to obtain purified cell populations, the limited quantity of RNA isolated makes it necessary to perform an RNA amplification step prior to microarray analysis. The linearity and reproducibility of two RNA amplification protocols--the Baugh protocol (Baugh et al., 2001, Nucleic Acids Res 29:E29) and an in-house protocol have been assessed by conducting microarray analyses. Cy3-labeled total RNA from the colorectal cell line Colo-205 was compared to Cy5-labeled Colo-205 amplified RNA (aRNA) generated with each of the two protocols, using a human 10K cDNA array. The correlation of the gene intensities between amplified and total RNA measured in the two channels of each microarray was 0.72 and 0.61 for the Baugh protocol and the in-house protocol, respectively. The two protocols were further evaluated using aRNA obtained from normal colonic crypt cross-sections isolated via LCM. In both cases a microarray profile representative of colonic mucosa was obtained; statistically, the Baugh protocol was superior. Furthermore, a substantial overlap between highly expressed genes in the Colo-205 cells and colonic crypts underscores the reliability of the microarray analysis of LCM-derived material. Taken together, these results demonstrate that LCM-derived tissue from histological specimens can generate abundant amounts of high-quality aRNA for subsequent microarray analysis.

Cell Line, Tumor↗

PubMed2002

Clinical significance of performing immunohistochemistry on cases with a previous diagnosis of cancer coming to a national comprehensive cancer center for treatment or second opinion.

Immunohistochemistry (IHC) is an important adjunctive test in diagnostic surgical pathology. We studied the clinical significance and outcomes in performing IHC on cases with a previous diagnosis of cancer who are coming to the Fox Chase Cancer Center (FCCC), a National Cancer Institute designated National Comprehensive Cancer Center (NCCC), for treatment and/or second opinion. We reviewed all the outside surgical pathology slide review cases seen at the FCCC for 1998 and 1999 in which IHC was performed. Cases were divided into the following: confirmation of outside diagnoses without and with prior IHC performed by the outside institution (groups A and B, respectively) and cases with a significant change in diagnosis without and with prior IHC performed by the outside institution (groups C and D, respectively). During 1998 and 1999, 6678 slide review cases were reviewed at the FCCC with an overall significant change in diagnosis in 213 cases (3.2%). IHC was performed on 186 of 6678 (2.7%) slide review cases with confirmation of the outside diagnosis in 152 (81.7%) cases and a significant change in diagnosis in 34 (18.3%) cases. Patient follow-up was obtained in 32 of 34 (94.1%) cases with a significant change in diagnosis (groups C and D), which confirmed the correctness of our diagnosis in 26 of 27 cases (96%; in five cases follow-up was inconclusive). We repeated the identical antibodies performed by the outside institutions in group D (37 antibodies) and group B (133 antibodies) with different results in 48.6% and 13.5%, respectively (overall nonconcordance 21.2%). In group D additional antibody tests beyond that performed by the outside institution were needed in 88.8% of cases to make a change of diagnosis. In the setting of a NCCC, reperforming and/or performing IHC on cases with a previous diagnosis of cancer is not a duplication of effort or misuse of resources. Repeating and/or performing IHC in this setting is important in the care and management of patients with cancer.

Biomarkers, Tumor↗