John D. Pfeifer, M.D., Ph.D.

DEPARTMENT OF Pathology & Immunology
Keywords: cancer, gene expression, molecular diagnosis

Within the Division of Surgical Pathology, my area of special interest is the application of molecular genetic testing to surgical pathology. Nucleic acid-based techniques are used to analyze chromosomal rearrangements by direct PCR amplification of breakpoints, reverse transcriptase polymerase chain reaction (RT-PCR) amplification of fusion transcripts, or by fluorescence in situ hybridization (FISH). Specific gene mutations are evaluated by direct DNA sequence analysis, loss of heterozygosity using non-random X chromosome inactivation and allelic loss. Additional techniques, such as quantitative (real-time) PCR, gene expression analysis using genechip arrays, Northern and Southern blot analysis, and western blot analysis, are under study to see if they are capable of providing diagnostically and prognostically relevent information.

Current investigations in the laboratory include application of molecular testing to the diagnosis of problematic solid tumors; identification of infectious pathogens (both bacterial and viral) in tissue biopsies; analysis of the specificity of well-characterized chromosomal translocations in soft tissue sarcomas; analysis of the specificity of gene expression profiles in soft tissue tumors; and mapping and cloning of novel translocations associated with specific tumor types.