Petr Kuglík

Report from the European Myeloma Network on interphase FISH in multiple myeloma and related disorders

The European Myeloma Network has organized two workshops on fluorescence in situ hybridization in multiple myeloma. The first aimed to identify specific indications and consensus technical approaches of current practice. A second workshop followed a quality control exercise in which 21 laboratories analyzed diagnostic cases of purified plasma cells for recurrent abnormalities. The summary report was discussed at the EHA Myeloma Scientific Working Group Meeting 2010. During the quality control exercise, there was acceptable agreement on more than 1,000 tests. The conclusions from the exercise were that the primary clinical applications for FISH analysis were for newly diagnosed cases of MM or frank relapse cases. A range of technical recommendations included: 1) material should be part of the first draw of the aspirate; 2) samples should be sent at suitable times to allow for the lengthy processing procedure; 3) most importantly, PCs must be purified or specifically identified; 4) positive cut-off levels should be relatively conservative: 10% for fusion or break-apart probes, 20% for numerical abnormalities; 5) informative probes should be combined to best effect; 6) in specialist laboratories, a single experienced analyst is considered adequate; 7) at least 100 PC should be scored; 8) essential abnormalities to test for are t(4;14), t(14;16) and 17p13 deletions; 9) suitable commercial probes should be available for clinically relevant abnormalities; 10) the clinical report should be expressed clearly and must state the percentage of PC involved and the method used for identification; 11) a retrospective European based FISH data bank linked to clinical data should be generated; and 12) prospective analysis should be centralized for upcoming trials based on the recommendations made. The European Myeloma Network aims to build on these recommendations to establish standards for a common European data base to define subgroups with prognostic significance.

Monoallelic and biallelic inactivation of TP53 gene in chronic lymphocytic leukemia: selection, impact on survival, and response to DNA damage

Deletion of TP53 gene, under routine assessment by fluorescence in situ hybridization analysis, connects with the worst prognosis in chronic lymphocytic leukemia (CLL). The presence of isolated TP53 mutation (without deletion) is associated with reduced survival in CLL patients. It is unclear how these abnormalities are selected and what their mutual proportion is. We used methodologies with similar sensitivity for the detection of deletions (interphase fluorescence in situ hybridization) and mutations (yeast functional analysis) and analyzed a large consecutive series of 400 CLL patients; a subset of p53-wild-type cases (n = 132) was screened repeatedly during disease course. The most common type of TP53 inactivation, ie, mutation accompanied by deletion of the remaining allele, occurred in 42 patients (10.5%). Among additional defects, the frequency of the isolated TP53 mutation (n = 20; 5%) and the combination of 2 or more mutations on separate alleles (n = 5; 1.3%) greatly exceeded the sole deletion (n = 3; 0.8%). Twelve patients manifested defects during repeated investigation; in all circumstances the defects involved mutation and occurred after therapy. Monoallelic defects had a negative impact on survival and impaired in vitro response to fludarabine. Mutation analysis of the TP53 should be performed before each treatment initiation because novel defects may be selected by previous therapies.

TP53 mutation profile in Chronic Lymphocytic Leukemia: Evidence for a disease specific profile from a comprehensive analysis of 268 mutations

The TP53 mutation profile in chronic lymphocytic leukemia (CLL) and the correlation of TP53 mutations with allele status or associated molecular genetics are currently unknown. We performed a large mutation analysis of TP53 at four centers and characterized the pattern of TP53 mutations in CLL. We report on 268 mutations in 254 patients with CLL. Missense mutations appeared in 74% of cases compared with deletions and insertions (20%), nonsense (4%) and splice site (2%) mutations. The majority (243 of 268) of mutations were located in the DNA-binding domain. Transitions were found in 131 of 268 mutations, with only 41 occurring at methylated CpG sites (15%), suggesting that transitions at CpGs are uncommon. The codons most frequently mutated were at positions 175, 179, 248 and 273; in addition, we detected a common 2-nt deletion in the codon 209. Most mutations (199 of 259) were accompanied by deletion of the other allele (17p–). Interestingly, trisomy 12 (without 17p–) was only found in one of 60 cases with TP53 mutation (without 17p–) compared with 60 of 16 in the cohort without mutation (P=0.006). The mutational profile was not different in the cohorts with and without previous therapy, suggesting that the mechanism underlying the development of mutations may be similar, independent of treatment.

Missense Mutations Located in Structural p53 DNA-Binding Motifs Are Associated With Extremely Poor Survival in Chronic Lymphocytic Leukemia

PURPOSE There is a distinct connection between TP53 defects and poor prognosis in chronic lymphocytic leukemia (CLL). It remains unclear whether patients harboring TP53 mutations represent a homogenous prognostic group. PATIENTS AND METHODS We evaluated the survival of patients with CLL and p53 defects identified at our institution by p53 yeast functional assay and complementary interphase fluorescence in situ hybridization analysis detecting del(17p) from 2003 to 2010. RESULTS A defect of the TP53 gene was identified in 100 of 550 patients. p53 mutations were strongly associated with the deletion of 17p and the unmutated IgVH locus (both P < .001). Survival assessed from the time of abnormality detection was significantly reduced in patients with both missense (P < .001) and nonmissense p53 mutations (P = .004). In addition, patients harboring missense mutation located in p53 DNA-binding motifs (DBMs), structurally well-defined parts of the DNA-binding domain, manifested a clearly shorter median survival (12 months) compared with patients having missense mutations outside DBMs (41 months; P = .002) or nonmissense alterations (36 months; P = .005). The difference in survival was similar in the analysis limited to patients harboring mutation accompanied by del(17p) and was also confirmed in a subgroup harboring TP53 defect at diagnosis. The patients with p53 DBMs mutation (at diagnosis) also manifested a short median time to first therapy (TTFT; 1 month). CONCLUSION The substantially worse survival and the short TTFT suggest a strong mutated p53 gain-of-function phenotype in patients with CLL with DBMs mutations. The impact of p53 DBMs mutations on prognosis and response to therapy should be analyzed in investigative clinical trials.

Nestin expression in the cell lines derived from glioblastoma multiforme

BackgroundNestin is a protein belonging to class VI of intermediate filaments that is produced in stem/progenitor cells in the mammalian CNS during development and is consecutively replaced by other intermediate filament proteins (neurofilaments, GFAP). Down-regulated nestin may be re-expressed in the adult organism under certain pathological conditions (brain injury, ischemia, inflammation, neoplastic transformation). Our work focused on a detailed study of the nestin cytoskeleton in cell lines derived from glioblastoma multiforme, because re-expression of nestin together with down-regulation of GFAP has been previously reported in this type of brain tumor.MethodsTwo cell lines were derived from the tumor tissue of patients treated for glioblastoma multiforme. Nestin and other cytoskeletal proteins were visualized using imunocytochemical methods: indirect immunofluorescence and immunogold-labelling.ResultsUsing epifluorescence and confocal microscopy, we described the morphology of nestin-positive intermediate filaments in glioblastoma cells of both primary cultures and the derived cell lines, as well as the reorganization of nestin during mitosis. Our most important result came through transmission electron microscopy and provided clear evidence that nestin is present in the cell nucleus.ConclusionDetailed information concerning the pattern of the nestin cytoskeleton in glioblastoma cell lines and especially the demonstration of nestin in the nucleus represent an important background for further studies of nestin re-expression in relationship to tumor malignancy and invasive potential.

Circulating serum microRNAs as novel diagnostic and prognostic biomarkers for multiple myeloma and monoclonal gammopathy of undetermined significance

Multiple myeloma still remains incurable in the majority of cases prompting a further search for new and better prognostic markers. Emerging evidence has suggested that circulating microRNAs can serve as minimally invasive biomarkers for multiple myeloma and monoclonal gammopathy of undetermined significance. In this study, a global analysis of serum microRNAs by TaqMan Low Density Arrays was performed, followed by quantitative real-time PCR. The analyses revealed five deregulated microRNAs: miR-744, miR-130a, miR-34a, let-7d and let-7e in monoclonal gammopathy of undetermined significance, newly diagnosed and relapsed multiple myeloma when compared to healthy donors. Multivariate logistical regression analysis showed that a combination of miR-34a and let-7e can distinguish multiple myeloma from healthy donors with a sensitivity of 80.6% and a specificity of 86.7%, and monoclonal gammopathy of undetermined significance from healthy donors with a sensitivity of 91.1% and a specificity of 96.7%. Furthermore, lower levels of miR-744 and let-7e were associated with shorter overall survival and remission of myeloma patients. One-year mortality rates for miR-744 and let-7e were 41.9% and 34.6% for the ‘low’ expression and 3.3% and 3.9% for the ‘high’ expression groups, respectively. Median time of remission for both miR-744 and let-7e was approximately 11 months for the ‘low’ expression and approximately 47 months for the ‘high’ expression groups of myeloma patients These data demonstrate that expression patterns of circulating microRNAs are altered in multiple myeloma and monoclonal gammopathy of undetermined significance and miR-744 with let-7e are associated with survival of myeloma patients.

Soft-tissue extramedullary multiple myeloma prognosis is significantly worse in comparison to bone-related extramedullary relapse

Even in the era of new drugs, multiple myeloma patients with extramedullary relapse have a poor prognosis. Our goal was to analyze the frequency and outcome of extramedullary relapse occurring in relapsed multiple myeloma patients. In total, we analyzed the prognosis of 226 relapsed multiple myeloma patients treated between 2005 and 2008 and evaluated them for presence of extramedullary relapse. We found evidence of extramedullary relapse in 24% (55 of 226) of relapsed multiple myeloma patients. In 14% (32 of 226) of patients, the lesions were not adjacent to the bone, while extramedullary relapse adjacent to the bone was documented in 10% (23 of 226) of cases. Patients without extramedullary relapse had significantly longer overall survival than patients with extramedullary relapse (109 vs. 38 months; P<0.001). Moreover, patients with soft tissue-related extramedullary relapse had significantly poorer overall survival compared to bone-related extramedullary relapse patients (30 vs. 45 months; P=0.022). Also, overall survival from diagnosis was as low as five months for soft tissue-related extramedullary relapse patients when compared to 12 months overall survival for bone-related extramedullary relapse. This is the first study that shows a significant difference in prognosis for different types of extramedullary relapse. If the extramedullary myeloma infiltration was not bone-related, overall survival after relapse was extremely short (5 months).

Gain of 1q21 Is an Unfavorable Genetic Prognostic Factor for Multiple Myeloma Patients Treated with High-Dose Chemotherapy

The prognostic significance of 1q21 gain, del(13)(q14), del(17)(p13), t(4;14)(p16.3;q32), and t(11;14)(q13;q32) detected by interphase fluorescein in situ hybridization (FISH) was studied in a cohort of 91 patients with newly diagnosed multiple myeloma (MM). 1q21 gain was detected in 37 of 91 patients (40.7%). In comparison with patients lacking 1q21 gain, patients with 1q21 gain had significantly shorter progression-free survival (PFS) (14.9 versus 27.4 months; P = .044) and worse 4-year overall survival (OS) (40.1% versus 76.2% of patients; P = <.001). PFS or OS were not influenced by the presence or absence of the other studied chromosomal abnormalities. Although the occurrence of 1q21 gain correlated with deletion of 13q14, the presence of 1q21 gain can be considered an independent prognostic factor, as no impact of del(13)(q14) as an isolated chromosomal abnormality on either PFS or OS has been observed. In comparison with patients lacking 1q21 gain, patients with 1q21 gain were significantly more likely to discontinue the preplanned treatment protocol because of disease progression or death. We conclude that 1q21 gain defines a prognostically unfavorable group of MM patients.

Complex karyotype and translocation t(4;14) define patients with high-risk newly diagnosed multiple myeloma: results of CMG2002 trial

Abstract The prognostic impact of chromosomal abnormalities was evaluated by fluorescence in situ hybridization with cytoplasmic immunoglobulin light chain staining (cIg-FISH) and by classical metaphase cytogenetics in a cohort of 207 patients with newly diagnosed multiple myeloma who were treated with high-dose therapy followed by autologous stem cell transplantation in the CMG2002 clinical trial. The incidence of chromosomal abnormalities detected by FISH was as follows: 52.7% for del(13)(q14), 6.5% for del(17)(p13), 18.6% for t(11;14)(q13;q32), 22.8% for t(4;14)(p16;q32) and 45.7% for gain(1)(q21). Metaphase cytogenetic analysis revealed a complex karyotype in 19.1% and hyperdiploidy in 21.7% of patients. The overall response rate was not influenced by the presence of any studied chromosomal abnormality. Patients with a complex karyotype, those with translocation t(4;14) and those with gain of the 1q21 locus had a shorter time to progression (TTP) and overall survival (OS). Other genomic changes such as translocation t(11;14) and del(13q) had less impact on TTP and OS. In multivariate analysis, complex karyotype, translocation t(4;14) and β2-microglobulin level > 2.5 mg/L were independent prognostic factors associated with poor overall survival. Their unfavorable prognostic impact was even more pronounced if they were present in combination. Patients with t(4;14) present together with a complex karyotype had the worst prognosis, with a median OS of only 13.2 months, whereas patients with a normal karyotype or karyotype with ≤ 2 chromosomal changes had the best outcome, with 3-year OS of 85.9%. In conclusion, complex karyotype, gain of 1q21 region and translocation t(4;14) are major prognostic factors associated with reduced survival of patients with newly diagnosed multiple myeloma treated with autologous stem cell transplantation.

Inactivation of p53 and deletion of ATM in B-CLL patients in relation to IgVH mutation status and previous treatment.

Inactivation of p53 and deletion of ATM in B-CLL patients in relation to IgVH mutation status and previous treatment