p53 protein expression in chronic lymphocytic leukemia

Abstract

Alterations in the function of the p53 pathway are frequently described in chronic lymphocytic leukemia (CLL), mostly associated with deletion of 17p13 and/or mutations of the TP53 gene. In the present study, we investigated 103 CLLs for the impact of protein expression of full-length p53 and its isoforms β and γ. A strong correlation between deletions of 17p13 and an accumulation of full-length p53 protein was found and was associated with a worse outcome compared to CLL with normal p53 (treatment-free survival p < 0.001, overall survival p = 0.04). Interestingly, the relative expression levels between full-length p53 protein and its isoforms β and γ were significantly altered in CLL even without deletions of 17p13, compared to normal B-cells (p = 0.005). Furthermore, CLLs with higher p53 protein ratios showed worse clinical courses compared to CLLs with lower p53 protein ratios. Taken together, the differential expression of p53 isoforms could disrupt the p53 response and contribute to CLL pathogenesis.

Keywords::

• CLL
• p53 protein expression
• p53β
• p53γ
• FISH

Acknowledgements

The authors are grateful to Frederike von Bonin, Adriana Hyla, Philipp Abstoß and Katharina Waldhelm for excellent technical assistance. Ludger Sellmann was supported by the IFORES program of the University of Duisburg-Essen Medical School. We also acknowledge support by the Deutsche Krebshilfe (MMML consortium).

Potential conflict of interest

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