Cell cycle expression of p53 protein, c-Myc gene product and tyrosine-phosphorylation level determined by image analysis in human breast cancer cells

Anal Quant Cytol Histol. 1996 Jun;18(3):233-40.


Objective: To investigate the cell cycle expression of p53 protein, c-myc gene product and tyrosine phosphorylation level in human breast cancer cells.

Study design: Using a multifluorescence imaging procedure, the concentration per cell in different phases of the cell cycle can be evaluated by analyzing the bivariate contour plot of DNA content versus antigen concentration.

Results: Low fluorescence intensity was observed in the G0/G1 phase for the three markers. The analysis of individual cells demonstrated that approximately 10% of cells were negative. During the G1/S transition, the fluorescence intensity of the three antigens increased rapidly. However, after the mild S-phase, the increase of c-myc was more marked than the tyrosine phosphorylation level, whereas p53 protein remained stable, with a slight tendency to decrease.

Conclusion: This study confirmed that the p53 protein and c-myc gene product could perform a regulatory function in G1/S transition and, consequently, may play an important role in malignant transformation. Like-wise, the variations of tyrosine kinase activity were linked to cellular progression throughout the cell cycle and could be a useful marker of alteration in the growth-factor signaling pathway. Thus, the multifluorescence imaging procedure may provide useful information on the mechanisms of the cell cycle and on malignant transformation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibody Specificity
  • Breast Neoplasms / genetics*
  • Cell Cycle / physiology*
  • DNA, Neoplasm / analysis
  • Female
  • Gene Expression Regulation, Neoplastic / physiology
  • Humans
  • Image Cytometry
  • Oncogenes / genetics
  • Phosphorylation
  • Proto-Oncogene Proteins c-myc / genetics*
  • Tumor Cells, Cultured / physiology
  • Tumor Suppressor Protein p53 / genetics*
  • Tyrosine / immunology
  • Tyrosine / metabolism*


  • DNA, Neoplasm
  • Proto-Oncogene Proteins c-myc
  • Tumor Suppressor Protein p53
  • Tyrosine