Biomedical subjects

Edmund A Gehan

Publications and source records attributed to Edmund A Gehan.

3 recordsLinked to original sources

PubMed2005

Gene selection for microarray data analysis using principal component analysis.

Principal component analysis (PCA) has been widely used in multivariate data analysis to reduce the dimensionality of the data in order to simplify subsequent analysis and allow for summarization of the data in a parsimonious manner. It has become a useful tool in microarray data analysis. For a typical microarray data set, it is often difficult to compare the overall gene expression difference between observations from different groups or conduct the classification based on a very large number of genes. In this paper, we propose a gene selection method based on the strategy proposed by Krzanowski. We demonstrate the effectiveness of this procedure using a cancer gene expression data set and compare it with several other gene selection strategies. It turns out that the proposed method selects the best gene subset for preserving the original data structure.

Gene Expression↗

PubMed2004

SCC-112, a novel cell cycle-regulated molecule, exhibits reduced expression in human renal carcinomas.

We report here the identification and an initial characterization of a novel cell cycle-regulated molecule, SCC-112. SCC-112 cDNA (6744 bp) encodes a longest open reading frame (ORF) comprised of 1297 amino acids, representing a approximately 150-kDa nuclear protein. SCC-112 mRNA and protein levels were relatively high during the G2/M phase of the cell cycle in MDA-MB 435 breast cancer cells. Transient expression of SCC-112 cDNA in COS-1 cells led to an increase in the number of cells in sub-G1 phase and enhanced activity of caspase-3, a downstream effector of apoptosis. Stable transfection of SCC-112 cDNA in MDA-MB 231 breast cancer cells also led to an increase in the number of cells in sub-G1 phase ( approximately 2-3-fold), indicative of apoptosis. The examination of the paired sets of human normal and tumor tissues revealed that the SCC-112 mRNA level was significantly high in normal breast and kidney tissues as compared to the corresponding primary tumor tissues (P<0.0001; breast, n=50, and kidney, n=20). Consistent with these observations, SCC-112 protein expression (150 kDa) was high in a majority of the normal renal tissues examined as compared to the matched renal tumor tissues (67%, 1.2-fold to>10-fold, n=18). Taken together, these findings suggest that the SCC-112 gene expression is likely to be associated with normal cell growth and proliferation.

Adult↗

PubMed2002

Treatment of children and adolescents with localized parameningeal sarcoma: experience of the Intergroup Rhabdomyosarcoma Study Group protocols IRS-II through -IV, 1978-1997.

BACKGROUND: We reviewed 611 patients with parameningeal sarcoma entered on Intergroup Rhabdomyosarcoma Study Group (IRSG) Protocols-II through IV (1978-1997), to delineate treatment results and evaluate prognostic factors. PROCEDURE: Primary sites were the middle ear/mastoid (N = 138), nasopharynx/nasal cavity (N = 235), paranasal sinuses (N = 132), parapharyngeal region (N = 29), and the pterygopalatine/infratemporal fossa (N = 77). Treatment was initial biopsy or surgery followed by multiagent chemotherapy and radiation therapy (XRT). Beginning in 1977, patients with cranial nerve palsy, cranial base bony erosion, and/or intracranial extension at diagnosis were considered as having meningeal involvement. They received triple intrathecal medications, whole brain XRT, and then spinal XRT. These treatments were successively eliminated from 1980 to 1991. RESULTS: The 611 patients' overall survival rate at 5 years was 73% (95% confidence interval, 70-77%). Favorable prognostic factors were: age 1-9 years at diagnosis; primary tumor in the nasopharynx/nasal cavity, middle ear/mastoid, or parapharyngeal areas; no meningeal involvement; and non-invasive tumors (T1). Thirty-five of 526 patients (6.7%) with information about presence/absence of meningeal involvement at diagnosis developed central nervous system (CNS) extension at 5-164 weeks (median, 46 weeks) after starting therapy. The estimated 5-year cumulative incidence rate of CNS extension during the study period was 5-7% (P = 0.88). CONCLUSIONS: Biopsy, XRT to the target volume, and systemic chemotherapy are successful treatments for the large majority of patients with localized parameningeal sarcoma. Carefully defining and irradiating the initial volume should reduce the risk of CNS failure. Aggressive initial surgical management of these patients is unnecessary.

Adolescent↗