Correlation of cell proliferation inhibition and apoptosis induction with expression of human beta 5 integrin on hematopoietic cells

OBJECTIVE: To investigate the function of the alpha v beta 5 integrin in hematopoietic cells. METHODS: Tissue culture, integrin expression vectors, gene transfer, polymerase chain reaction (PCR), apoptosis analyses and cytometic analysis were made on hematopoietic cells. RESULTS: The beta 5 integrin cDNA was not expressed in hematopoietic cells following exposure to the beta 5 integrin retrovirus vector pG beta 5CHT. Unbalanced expression of the alpha v beta 3 and alpha v beta 5 integrins occurred during apoptosis induced by serum depletion and upon differentiation. The treatment of hematopoietic cells with anti-alpha v beta 5 monoclonal antibody inhibited apoptosis induced by serum depletion. Inducible expression of the beta 5 integrin cDNA in the hematopoietic cell line K562 caused cellular proliferation inhibition. CONCLUSION: The alpha v beta 5 integrin cDNA in hematopoietic cells can inhibit the proliferation of the hematopoietic cell, cause the differentiation of the hematopoietic cells and induce the apoptosis of the hematopoietic cells.