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S Dalrymple

Publications and source records attributed to S Dalrymple.

7 recordsLinked to original sources
PubMed2004

Proteomic analysis of dunning prostate cancer cell lines with variable metastatic potential using SELDI-TOF.

BACKGROUND: Surface enhanced laser desorption and ionization-time-of-flight (SELDI-TOF) is an evolving proteomic technology for improving biomarker discovery that allows for rapid and sensitive analysis of complex protein mixtures generated from body fluids, cells, and/or tissues. SELDI--based profiling identifies unique, differentially expressed proteins relating to specific cancer-related disease states. We utilized SELDI-TOF following pre-processing with molecular separation and chemical fractionation of cell membrane extracts from three Dunning rat prostate cancer cell lines of varying metastatic potential to search novel proteins that are differentially expressed. METHODS: Dunning rat cell sublines of variable (%) metastatic potential; G (0%), AT-1 (20%), and Mat-Ly-Lu (100%) were cultured in two different laboratories. Cell lysis was performed in a homogenation buffer (320 mM sucrose/50 mM Tris/0.5 mM PSMF) using Dounce homogenation. After centrifugation, the membrane pellet was washed 2x and then solublized in 2% CHAPS/8 M urea. This sample was further processed using positive pressure molecular ultrafiltration at 30 kDa or precipitation with 50% ammonium sulfate. Next, each sample was applied to an IMAC3-Ni ProteinChip (Ciphergen Biosystems, Freemont, CA) and analyzed using Ciphergen's Protein Biology System with protein peak analysis software. RESULTS: SELDI-TOF analysis differentiated the three Dunning rat cell sublines based upon protein concentration normalized profiles between 5,000 and 20,000 Da. The preparations from the three cells lines showed clear differences when the extracts from the metastatic sublines (AT-1 and MLL) were compared to the benign subline (G) for proteins with molecular weights of 9 kDa (decrease), 12 kDa (significant decrease), 14 kDa (decrease), and 17 kDa (significant gain). After pre-processing extracts with ammonium sulfate and molecular ultrafiltration, the molecular profile changes from one subline to the next became more apparent. Our results were reproducible using multiple runs including from Dunning cells cultured in a separate laboratory, and using different lots of SELDI ProteinChips. CONCLUSIONS: The application of SELDI-TOF to a series of Dunning rat prostate cancer cell lines illustrated apparent changes in protein profiles among the three cell lines with known differences in metastatic biologic activity. SELDI-TOF identified four reproducible changes in protein expression in the AT1 and MLL metastatic cell sublines. Three of the expression changes were manifested as decreases, but one protein (17 kDa) was over-expressed in the AT1 and MLL cell lines. Emphasis will be placed on the isolation, purification, and characterization of the 17 kDa over-expressed protein and its potential role in PCa metastasis.

Animals↗
PubMed1993

Hematopoietic growth factor receptor genes as markers of lineage commitment during in vitro development of hematopoietic cells.

We have used two in vitro models to identify genes whose expression may serve as markers of lineage commitment during the development of hematopoietic stem cells. One system involves the development in vitro of blastocyst-derived embryonic stem cells into embryoid bodies. The second involves culturing of day 3.5 blastocysts in vitro under conditions that support their development into yolk saclike cysts. In both cases, hematopoietic cells arise in a manner that closely mimics the normal process occurring in the yolk sac of the early mouse embryo. We have focused our analysis on the expression of mRNAs for 15 hematopoietic growth factor receptor genes and other genes expressed in a hematopoietic lineage-specific manner. Although some growth factor receptor genes are apparently expressed constitutively during in vitro development, there are several classes of genes that undergo a highly consistent pattern of induction in both model systems. Genes induced early include those encoding the shared beta subunits of the interleukin-3 (IL-3), IL-5, and granulocyte-macrophage colony-stimulating factor (GM-CSF) receptors; those induced at intermediate times include the c-fms, G-CSF receptor, and CD34 genes; and a gene induced late during in vitro development is the IL-7 receptor gene. The defined temporal order for the expression of these genes suggests that they may be useful as markers for multiple stages in the development of different hematopoietic cell lineages during embryogenesis.

Animals↗
PubMed1989

Enhanced carcinogenesis in the proximal small intestine of the rat following rumenectomy.

Various techniques have been used to enhance carcinogenesis in experimental animals. This study examines the effects of the excision of the forestomach (rumen), a squamous epithelial pouch of the rat, on the incidence and distribution of intestinal neoplasms induced by 1,2-dimethylhydrazine (DMH). Thirty-four male Sprague-Dawley rats were randomly assigned to control and experimental groups. The experimental group was subjected to an excision of the rumen while the control group underwent a gastro-rumenotomy and closure. Following a two week recovery period, each animal was weighed and injected with DMH (20 mgm/kg body wt) on a weekly basis for 22 weeks. At 24 weeks, the 32 surviving rats were sacrificed and the number, location, and histology of the neoplasms in the intestinal tract of each rat were noted. Rumenectomy resulted in a statistically increased incidence of neoplasms in the proximal small bowel (mean of 1.3 +/- 0.01 neoplasms/rat) when compared with the control group (mean of 0.1 +/- 0.2 neoplasms/rat) (p less than 0.001); but did not influence the incidence, distribution, or histology of colonic neoplasms between control and experimental animals. All neoplasms of the proximal small bowel when examined histologically were classified as invasive adenocarcinomas. The colon contained adenomata and carcinoma in situ, as well as adenocarcinomas. It is therefore concluded that excision of the rumen of the rat stomach selectively promotes malignant formation in the proximal small bowel following repeated injections of DMH.

Adenocarcinoma↗
PubMed1983

Sacral plexus nerve sheath tumor: case report.

A young woman with chronic sciatica was found to have an intrapelvic sacral plexus nerve sheath tumor. Computed tomography of the pelvis was used to delineate this unusual site of tumor development. The case report and a discussion of pelvic nerve sheath tumors are presented.

Adult↗