Immunolocalization and cell expression of lung resistance-related protein (LRP) in normal and tumoral human respiratory cells

J Histochem Cytochem. 2007 Aug;55(8):773-82. doi: 10.1369/jhc.7A7176.2007. Epub 2007 Apr 16.

Abstract

Lung resistance-related protein (LRP) is an integral part of the multidrug resistance (MDR) phenotype involved in cell resistance toward xenobiotics or chemotherapy. The aim of this study was to compare the intracellular localization and cell expression of LRP in normal bronchial cells and their tumoral counterparts from non-small cell lung cancer (NSCLC). LRP expression was also investigated concurrently with DNA ploidy and chromosome 16 (lrp gene locus) aberrations. Confocal microscopy showed that LRP localization was exclusively intracytoplasmic regardless of the cell type and was never observed in the nuclear pore complex. Flow cytometry demonstrated a similar level of LRP expression in normal bronchial cells and in cancer cells from NSCLC samples. FISH analysis, performed to evaluate the number of chromosome 16 and lrp loci, demonstrated a significant gain of chromosome 16 in DNA aneuploid tumors. Furthermore, we did not find any link between LRP expression and DNA ploidy status or chromosome 16 number. These results suggest that LRP expression observed in NSCLC, maintained through the carcinogenesis process of respiratory cells, is not altered by the increased number of copies of chromosome 16 and probably controlled by mechanisms different from those of MRP1 expression, whereas both proteins are associated with the MDR phenotype.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aneuploidy
  • Bronchi / cytology
  • Bronchi / metabolism*
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Cell Line, Tumor
  • Chromosome Aberrations
  • Chromosomes, Human, Pair 16 / genetics
  • Flow Cytometry
  • Gene Dosage
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism*
  • Microscopy, Confocal
  • Respiratory Mucosa / cytology
  • Respiratory Mucosa / metabolism*
  • Vault Ribonucleoprotein Particles / biosynthesis
  • Vault Ribonucleoprotein Particles / genetics
  • Vault Ribonucleoprotein Particles / metabolism*

Substances

  • Vault Ribonucleoprotein Particles
  • major vault protein