Tumor Protein 53 Gene Mutations Without 17p13 Deletion Have No Significant Clinical Implications in Chronic Lymphocytic Leukemia. Detection of a New Mutation.

BACKGROUND: The tumor protein p53 (TP53) gene may be inactivated through 17p13 deletion, somatic mutations, or both. In chronic lymphocytic leukemia (CLL) although 17p13 deletion is correlated with poor prognosis, the role of sole TP53 mutations remains controversial. MATERIALS AND METHODS: We carried out a mutation analysis of TP53 gene in 72 patients with CLL. RESULTS: Seventy-one (98.6%) patients carried the polymorphic site c.215C>G, p.Pro72Arg, but its presence was not correlated with overall survival (OS). Moreover, 19 (26.4%) patients carried a mutation of TP53. Among the eight detected mutations, to our knowledge, one (c.587G>A) has never been reported in the past. There was a correlation of the mutation burden with the stage of the disease (p=0.022), but not with OS. None of the detected mutations was individually correlated with OS. CONCLUSION: The clinical significance of TP53 mutations is still a matter of debate and larger studies and meta-analyses are required to reach an unequivocal conclusion.

Survivin messenger RNA levels in Epstein-Barr virus-positive patients with leukemic low-grade B-cell lymphomas expressing the latent membrane protein 1: evidence of apoptotic function?

BACKGROUND: Epstein-Barr virus (EBV) is a ubiquitous pathogen that chronically infects B lymphocytes and is implicated in the pathogenesis of lymphoproliferative diseases. Latent membrane protein 1 (LMP1), the major oncoprotein of the virus, has been shown to inhibit apoptosis and trigger survivin expression in malignant cell lines. LMP1 expression has been detected in patients with chronic lymphocytic leukemia, but its properties have not been studied in patients with low-grade B-cell lymphomas. Recent data show that LMP1 can simultaneously induce and inhibit apoptosis in B cells. We detected LMP1 messenger RNA (mRNA) in patients with leukemic low-grade B-cell lymphoma and correlated the expression of the antiapoptotic molecule survivin to that of LMP1 in this group of patients. PATIENTS AND METHODS: Peripheral whole blood from 64 patients with low-grade B-cell lymphoma was tested by quantitative reverse transcriptase-polymerase chain reaction (PCR) for the presence of the BXLF-1 gene of EBV, and positive samples were tested by conventional PCR for LMP1 expression. Accordingly, survivin mRNA levels were measured by quantitative reverse transcriptase PCR in all samples and compared between LMP1-positive (LMP1(+)) and LMP1(-) patients. RESULTS: The BXLF-1 gene was detected in 27 of 64 patients (42%). LMP1 was expressed in 22 of 27 (81%) EBV(+) patients. Survivin expression was found to be 6.36 times higher in LMP1(-) patients than in LMP1(+) patients (P = .008). CONCLUSION: Our results imply that in patients with non-EBV-related leukemic low-grade B-cell lymphoma, LMP1 expression is possibly correlated to apoptosis, as indicated by the lower survivin mRNA levels in LMP1(+) patients.