Constitutional and acquired genetic variants in ARID5B in pediatric B-cell precursor acute lymphoblastic leukemia.

Constitutional polymorphisms in ARID5B are associated with an increased risk of developing high hyperdiploid (HeH; 51-67 chromosomes) pediatric B-cell precursor acute lymphoblastic leukemia (BCP ALL). Here, we investigated constitutional and somatic ARID5B variants in 1335 BCP ALL cases from five different cohorts, with a particular focus on HeH cases. In 353 HeH ALL that were heterozygous for risk alleles and trisomic for chromosome 10, where ARID5B is located, a significantly higher proportion of risk allele duplication was seen for the SNPs rs7090445 (p = 0.009), rs7089424 (p = 0.005), rs7073837 (p = 0.03), and rs10740055 (p = 0.04). Somatic ARID5B deletions were seen in 16/1335 cases (1.2%), being more common in HeH than in other genetic subtypes (2.2% vs. 0.4%; p = 0.002). The expression of ARID5B in HeH cases with genomic deletions was reduced, consistent with a functional role in leukemogenesis. Whole-genome sequencing and RNA-sequencing in HeH revealed additional somatic events involving ARID5B, resulting in a total frequency of 3.6% of HeH cases displaying a somatic ARID5B aberration. Overall, our results show that both constitutional and somatic events in ARID5B are involved in the leukemogenesis of pediatric BCP ALL, particularly in the HeH subtype.

Characterisation of children and adolescents with acute lymphoblastic leukaemia who presented without peripheral blood blasts at diagnosis.

Of 1003 children with acute lymphoblastic leukaemia (ALL), 147 (14.7%) presented without peripheral blood blasts (PBB). While absence of PBB was not independently associated with survival outcomes when compared to those with PBB, patients without PBB had distinct genetic and clinical characteristics. Notably, we identified a novel genotype-phenotype relationship, in that the patients without PBB had a significantly higher incidence of hyperdiploid B-ALL, accounting for almost half of all patients without PBB (46.9% vs. 22.7%, p < 0.001). Further, absence of PBB was associated with decreased rates of leukaemia involvement of the central nervous system (p < 0.001).

Overview on Aneuploidy in Childhood B-Cell Acute Lymphoblastic Leukemia.

Recent years have brought significant progress in the treatment of B-cell acute lymphoblastic leukemia (ALL). This was influenced by both the improved schemes of conventionally used therapy, as well as the development of new forms of treatment. As a consequence, 5-year survival rates have increased and now exceed 90% in pediatric patients. For this reason, it would seem that everything has already been explored in the context of ALL. However, delving into its pathogenesis at the molecular level shows that there are many variations that still need to be analyzed in more detail. One of them is aneuploidy, which is among the most common genetic changes in B-cell ALL. It includes both hyperdiploidy and hypodiploidy. Knowledge of the genetic background is important already at the time of diagnosis, because the first of these forms of aneuploidy is characterized by a good prognosis, in contrast to the second, which is in favor of an unfavorable course. In our work, we will focus on summarizing the current state of knowledge on aneuploidy, along with an indication of all the consequences that may be correlated with it in the context of the treatment of patients with B-cell ALL.

In Utero Development and Immunosurveillance of B Cell Acute Lymphoblastic Leukemia.

OPINION STATEMENT: Acute lymphoblastic leukemia (ALL) is the most frequent type of pediatric cancer with a peak incidence at 2-5 years of age. ALL frequently begins in utero with the emergence of clinically silent, preleukemic cells. Underlying leukemia-predisposing germline and acquired somatic mutations define distinct ALL subtypes that vary dramatically in treatment outcomes. In addition to genetic predisposition, a second hit, which usually occurs postnatally, is required for development of overt leukemia in most ALL subtypes. An untrained, dysregulated immune response, possibly due to an abnormal response to infection, may be an important co-factor triggering the onset of leukemia. Furthermore, the involvement of natural killer (NK) cells and T helper (Th) cells in controlling the preleukemic cells has been discussed. Identifying the cell of origin of the preleukemia-initiating event might give additional insights into potential options for prevention. Modulation of the immune system to achieve prolonged immunosurveillance of the preleukemic clone that eventually dies out in later years might present a future directive. Herein, we review the concepts of prenatal origin as well as potential preventive approaches to pediatric B cell precursor (BCP) ALL.

Sister chromatid cohesion defects are associated with chromosomal copy number heterogeneity in high hyperdiploid childhood acute lymphoblastic leukemia.

High hyperdiploid acute lymphoblastic leukemia (ALL) is one of the most common malignancies in children. The main driver event of this disease is a nonrandom aneuploidy consisting of gains of whole chromosomes but without overt evidence of chromosomal instability (CIN). Here, we investigated the frequency and severity of defective sister chromatid cohesion-a phenomenon related to CIN-in primary pediatric ALL. We found that a large proportion (86%) of hyperdiploid cases displayed aberrant cohesion, frequently severe, to compare with 49% of ETV6/RUNX1-positive ALL, which mostly displayed mild defects. In hyperdiploid ALL, cohesion defects were associated with increased chromosomal copy number heterogeneity, which could indicate increased CIN. Furthermore, cohesion defects correlated with RAD21 and NCAPG mRNA expression, suggesting a link to reduced cohesin and condensin levels in hyperdiploid ALL. Knockdown of RAD21 in an ALL cell line led to sister chromatid cohesion defects, aberrant mitoses, and increased heterogeneity in chromosomal copy numbers, similar to what was seen in primary hyperdiploid ALL. In summary, our study shows that aberrant sister chromatid cohesion is frequent but heterogeneous in pediatric high hyperdiploid ALL, ranging from mild to very severe defects, and possibly due to low cohesin or condensin levels. Cases with high levels of aberrant chromosome cohesion displayed increased chromosomal copy number heterogeneity, possibly indicative of increased CIN. These abnormalities may play a role in the clonal evolution of hyperdiploid pediatric ALL.

Multicolor flow cytometry immunophenotyping and characterization of aneuploidy in pediatric B-cell precursor acute lymphoblastic leukemia.

The aim of this study was to assess the incidence of DNA aneuploidy in Polish children with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) and the relationship between aneuploidy and immunological phenotype, age, leukocyte count, S-phase fraction (SPF) and early response to induction chemotherapy assessed by the percentage of residual blast cells in bone marrow aspirates. The study group consisted of 267 patients. DNA content and immunophenotype were assessed in the bone marrow before treatment using multicolor flow cytometry (FC). DNA aneuploidy was detected in 50/267 (19%) patients. High hyperdiploidy was found to be associated with lower leukocyte count (p = 0.006) and common ALL immunophenotype. Flow cytometry analysis revealed that high hyperdiploid BCP-ALL patients showed significantly higher expression of CD9, CD20, CD22, CD58, CD66c, CD86 and CD123 antigens as compared to other groups of ploidy. In contrast, CD45 showed decreased expression. The percentage of leukemic blasts at diagnosis was lower in high hyperdiploid BCP-ALL cases than in diploid (79% vs. 85.7%, p = 0.001). The difference in minimal residual disease (MRD) levels on day 15 and 33 of induction therapy between analyzed groups was not significant. This study showed that high hyperdiploidy is associated with lower WBC count and specific immunological phenotype. Flow cytometric evaluation of expression of selected antigens can be used for fast identification of markers of aneuploidy in pediatric BCP-ALL, before genetic tests results are available. Understanding the biological significance of aneuploidy in leukemia can potentially be exploited therapeutically using targeted therapies against specific blast cell subclones.

Predisposing germline mutations in high hyperdiploid acute lymphoblastic leukemia in children.

High hyperdiploidy (HD) is the most common cytogenetic subtype of childhood acute lymphoblastic leukemia (ALL), and a higher incidence of HD has been reported in ALL patients with congenital cancer syndromes. We assessed the frequency of predisposing germline mutations in 57 HD-ALL patients from the California Childhood Leukemia Study via targeted sequencing of cancer-relevant genes. Three out of 57 patients (5.3%) harbored confirmed germline mutations that were likely causal, in NBN, ETV6, and FLT3, with an additional six patients (10.5%) harboring putative predisposing mutations that were rare in unselected individuals (<0.01% allele frequency in the Exome Aggregation Consortium, ExAC) and predicted functional (scaled CADD score ≥ 20) in known or potential ALL predisposition genes (SH2B3, CREBBP, PMS2, MLL, ABL1, and MYH9). Three additional patients carried rare and predicted damaging germline mutations in GAB2, a known activator of the ERK/MAPK and PI3K/AKT pathways and binding partner of PTPN11-encoded SHP2. The frequency of rare and predicted functional germline GAB2 mutations was significantly higher in our patients (2.6%) than in ExAC (0.28%, P = 4.4 × 10-3 ), an observation that was replicated in ALL patients from the TARGET project (P = .034). We cloned patient GAB2 mutations and expressed mutant proteins in HEK293 cells and found that frameshift mutation P621fs led to reduced SHP2 binding and ERK1/2 phosphorylation but significantly increased AKT phosphorylation, suggesting possible RAS-independent leukemogenic effects. Our results support a significant contribution of rare, high penetrance germline mutations to HD-ALL etiology, and pinpoint GAB2 as a putative novel ALL predisposition gene.

Aneuploidy in children with relapsed B-cell precursor acute lymphoblastic leukaemia: clinical importance of detecting a hypodiploid origin of relapse.

Aneuploidy is common in paediatric B-cell precursor acute lymphoblastic leukaemia (ALL). Specific subgroups, such as high hyperdiploidy (>50 chromosomes or DNA Index ≥1·16) and hypodiploidy (<45 chromosomes), predict outcome of patients after primary treatment. Whether aneuploidy has a prognostic value for relapsed disease is yet to be determined. Using DNA index and centromere screening by multiplex ligation-dependent probe amplification, we investigated aneuploidy in 413 children treated for first relapse of B-cell precursor ALL according to the ALL-REZ BFM 2002 protocol. Ten-year event-free survival of patients with high hyperdiploid relapses approached 70%, whereas it was only 40% in low hyperdiploid relapses. Three patients with apparent hyperdiploid relapse had TP53 mutations. In these cases, array-based allelotyping revealed a hypodiploid origin with absence of the hypodiploid founder clone (masked hypodiploidy). Collectively, patients with evident or masked hypodiploid relapses showed an extremely low event-free survival rate of 9%. Importantly, the current relapse risk stratification did not identify cases with masked hypodiploidy as high-risk patients, due to their favourable clinical presentation. In multivariate analysis, hypodiploidy proved to be an independent prognostic factor. This finding supports stratification of relapses with hypodiploid origin into high-risk arms in future trials or allocation of patients to alternative treatment approaches.

GAS6 Oncogene and Reverse MLLT3-KMT2A Duplications in an Infant with Acute Myeloid Leukemia and a Novel Complex Hyperdiploid Karyotype: Detailed High-Resolution Molecular Cytogenetic Studies.

Pediatric acute myeloid leukemia (AML) is a highly heterogeneous disease, presenting cytogenetic and molecular abnormalities which turned out to be critical prognostic factors. Ploidy changes as gain or loss of individual chromosomes are rare in AML, occurring only in about 1-2% of the affected children. Hyperdiploid karyotypes are exceedingly rare in infants less than 12 months of age. In this age group, structural rearrangements involving the KMT2A gene occur in about 58% of the cases. Among them, the translocation t(9;11)(p22;q23), KMT2A-MLLT3, is the most common abnormality accounting for approximately 22% of KMT2A rearrangements in infant AML cases. Here, we describe a 7- month-old girl with a history of fever and severe diarrhea, and a physical examination remarkable for pallor and hepatosplenomegaly. A novel complex hyperdiploid karyotype 53,XX,+X,+6,t(9;11)(p21.3;q23.3),+der(9)t(9;11)(p21.3;q23.3),dup(13)(q31q34),+14,+19,+21,+22 was characterized by high-resolution molecular cytogenetic approaches. Fluorescence in situ hybridization, multiplex-FISH, and multicolor chromosome banding were applied, revealing 2 reverse MLLT3-KMT2A fusions and a duplication of the GAS6 oncogene. Our work suggests that molecular cytogenetic studies are crucial for the planning of a proper strategy for risk therapy in AML infants with hyperdiploid karyotypes.

Hyperdiploidy as a rare event that accompanies poor prognosis markers in CLL.

The presence of chromosomal gains other than trisomy 12 in chronic lymphocytic leukaemia (CLL) is unusual. However, some patients may show gains on several chromosomes simultaneously suggesting a hyperdiploid karyotype. OBJECTIVE: The objective of this study was to analyse by FISH the frequency and prognostic impact of hyperdiploidy in CLL. METHOD: A review of 1359 consecutive cases diagnosed with CLL referred for FISH analysis to a unique institution was carried out. Hyperdiploidy was considered when a gain of at least three of the five FISH probes used was observed. RESULTS: Seven cases (0.51%) with hyperdiploidy were found, confirming that it is a rare event in this disease. Although most patients presented with early Binet stages at diagnosis, six of seven (86%) shortly progressed. The median of time to the first therapy (TTFT) and overall survival (OS) for the patients with hyperdiploidy were short (1.4 months and 20 months, respectively). Moreover, comparing them with a control group of patients (non-hyperdiploid) with completed follow-up data, TTFT and OS of the patients with hyperdiploidy were significantly shorter than the control group. CONCLUSION: The presence of hyperdiploidy is uncommon and probably associated with poor prognostic markers in CLL.

Treatment of children with acute lymphoblastic leukemia with risk group based intensification and omission of cranial irradiation: A Korean study of 295 patients.

BACKGROUND: Recent studies indicate 70-80% event-free survival (EFS) for pediatric acute lymphoblastic leukemia (ALL). In this study, we report the outcome of 295 children and adolescents treated at our institution, with stratification into four risk groups, and omission of cranial irradiation in all patients. PROCEDURE: Patients were diagnosed from January 2005 to December 2011 and classified and treated as low, standard, high, and very high risk groups. A delayed intensification phase was given twice for high and very high risk groups. None of the patients received cranial irradiation for central nervous system (CNS) prophylaxis. RESULTS: The 10-year EFS and overall survival (OS) were 78.5 ± 2.5% and 81.9 ± 2.7%, respectively. EFS according to risk group was as follows: low risk 91.2 ± 3.7%, standard risk 98.1 ± 1.9%, high risk 81.5 ± 4.3%, very high risk 59.4 ± 5.3%. In a multivariate analysis, high hyperdiploidy and infant ALL were significant predictors of EFS. Cumulative incidence of any relapse, isolated CNS relapse, and any CNS relapse were 17.1 ± 2.3%, 1.5 ± 0.7%, and 2.3 ± 0.9%, respectively. Other events included infection-related deaths during remission induction chemotherapy (3), primary refractory disease (2), and treatment-related deaths in first complete remission (8). CONCLUSIONS: In this single-institution study of Korean pediatric ALL patients, risk group based intensification with omission of cranial irradiation resulted in EFS comparable to previous studies, excellent survival of low- and standard-risk patients, and a low rate of CNS relapse.

Altered cytological parameters in buccal cells from individuals with mild cognitive impairment and Alzheimer's disease.

Previous studies have shown that mild cognitive impairment (MCI) may be reflective of the early stages of more pronounced neurodegenerative disorders such as Alzheimer's disease (AD). There is a need for a minimally invasive and inexpensive diagnostic to identify those who exhibit cellular pathology indicative of MCI and AD risk so that they can be prioritized for primary preventative measures. The hypothesis was that a minimally invasive approach using cytological markers in isolated buccal mucosa cells can be used to identify individuals of both MCI and AD. An automated buccal cell assay was developed using laser scanning cytometry (LSC) to measure buccal cell type ratios, nuclear DNA content and shape, and neutral lipid content of buccal cells from clinically diagnosed AD (n = 13) and MCI (n = 13) patients prior to treatment compared to age- and gender-matched controls (n = 26). DNA content was significantly higher in all cell types in both MCI (P < 0.01) and AD (P < 0.05) compared with controls mainly due to an increase in >2N nuclei. Abnormal nuclear shape (circularity) was significantly increased in transitional cells in MCI (P < 0.001) and AD (P < 0.01) when compared to controls. In contrast, neutral lipid content (as measured by Oil red O "ORO" staining) of buccal cells was significantly lower in the MCI group (P < 0.05) compared with the control group. The ratio of DNA content/ORO in buccal basal cells for both MCI and AD was significantly higher compared to the control group, with ratios for MCI being approximately 2.8-fold greater (P < 0.01) and AD approximately 2.3-fold greater (P < 0.05) than the control group. Furthermore, there was a strong negative correlation between buccal cell DNA content and ORO content in the AD group (r(2) = 0.75, P < 0.0001) but not in MCI or controls. The changes in the buccal cell cytome observed in this study could prove useful as potential biomarkers in identifying individuals with an increased risk of developing MCI and eventually AD.

Cytogenetic classification in Korean multiple myeloma patients: prognostic significance of hyperdiploidy with 47-50 chromosomes and the number of structural abnormalities.

Chromosomal abnormalities are important prognostic factors for patients diagnosed with multiple myeloma (MM). We retrospectively reviewed the clinical and laboratory data of 525 MM patients to assess the abnormalities frequently found by conventional cytogenetic analysis and to determine their relationship to prognosis and clinical parameters. Samples from 222 (42.3%) patients had abnormal karyotypes. Hyperdiploidy-1 (>50 chromosomes), hyperdiploidy-2 (47-50 chromosomes), pseudodiploidy (46 with abnormalities), and hypodiploidy (<46 chromosomes) were found in 55, 44, 42, and 81 patients, respectively. The median overall survival (OS) was significantly shorter in patients with hyperdiploidy-2 (20.9 months), pseudodiploidy (19.9 months), and hypodiploidy (18.3 months) compared with patients with normal karyotype (66 months) and hyperdiploidy-1 (55.4 months) (P < 0.001). Among patients with chromosomal abnormalities, those with 1q amplification had a shorter median OS (17 vs. 25.1 months, P = 0.018). Patients with a chromosome 13 deletion in the pseudodiploidy group also had a shorter OS. A karyotype with more than six structural abnormalities was found to have the most significant independent prognostic value by multivariate analysis. These data show that hyperdiploidy with 47-50 chromosomes should be recategorized as an unfavorable risk group, and the number of structural abnormalities needs to be considered as an important factor for prognosis. In conclusion, our findings imply that subclassification of chromosomal abnormalities by conventional cytogenetics could be applied to the prognostic assessment of MM.

Sequential and hierarchical chromosomal changes and chromosome instability are distinct features of high hyperdiploid pediatric acute lymphoblastic leukemia.

BACKGROUND: Pathogenesis of the non-random accumulation of extra chromosomes in the low and high hyperdiploid (HeL, HeH) pre-B pediatric acute lymphoblastic leukemia (B-pALL) is largely unknown, and has been clarified with respect only to tetrasomic chromosomes. We analyzed the hierarchy of changes in chromosome number and chromosomal instability, as well as clonal heterogeneity and evolution, in the untreated bone marrow cell samples from 214 B-pALL patients. PROCEDURE: Applying relocation, 2 × 4 color interphase fluorescence in situ hybridization was used to detect copy number alterations (CNAs) of the most commonly involved chromosomes, 4, 6, 10, 14, 17, 18, 21, and X. This approach allowed us to acquire a dataset correlated for all eight parameters. RESULTS: Based on chromosome number, an average of 6.9 and 10.2, whereas according to unique constellation 15.3 and 26.7 subclones could be identified in the HeL and HeH subgroups, respectively. Cluster analysis revealed the order of CNAs to chromosomes was highly conserved, and network analysis indicated changes in chromosome number were sequential for 80-90% of all numerical aberrations. Significant chromosome instability was revealed in both subgroups of leukemia. CONCLUSIONS: Data generated using this new approach indicate that chromosomal instability, which causes heterogeneity in the subclonal landscape, and the sequential changes to chromosome numbers, are both determining factors in the pathomechanism of the hyperdiploid B-pALL. These new observations could prompt research into the mitotic machinery of leukemic cells to identify new therapeutic targets for treating this disease.

Masked hypodiploidy in anaplastic meningiomas by duplication of the original clone found in atypical meningiomas: illustration of the evolution of genetic alterations.

Meningiomas are common, usually benign neoplasms of the central nervous system. Atypical and anaplastic meningiomas can be aggressive, show more rapid growth, and a greater propensity to recur following resection. General consensus believes that genetic abnormalities leading to anaplastic transformation are present at initial tumor presentation; however, this has not been demonstrated by array-comparative genome hybridization. We confirm the hypothesis by showing the evolution of genetic alterations in the transformation of an atypical meningioma to an anaplastic meningioma. Additionally, we provide potential genes responsible for malignant transformation of meningiomas, which, with further research, may provide diagnostic and therapeutic implications.

Pattern of chromosome involvement in childhood hyperdiploid pre-B-cell acute lymhoblastic leukemia cases from India.

BACKGROUND: Hyperdiploid pre-B-cell acute lymhoblastic leukemia (pre-B-ALL) is a common form of childhood leukemia with very good prognosis with present day chemotherapy. However, the chromosomal composition of the hyperdiploidy has not been extensively studied and possible mechanism for this pathology remains so far conjectural. OBJECTIVE: To analyze the pattern of chromosome involvement in a cohort of childhood hyperdiploid pre-B-ALL from India and from this pattern to develop an understanding on the causation of such pathology. Whether such patients also carry translocations and FLT3 mutations in addition to their hyperdiploid karyotype. MATERIALS AND METHODS: One hundred and twenty-six childhood pre-B-ALL patients were studied. Bone marrow aspirate of these patients were evacuated for morphology, FAB classification, immunophenotyping and both conventional and molecular cytogenetics. RESULTS: Of 126 patients with pre-B-ALL (age 2-15 years), 90 patients with abnormal karyotype showed 50 with hyperdiploid karyotype (50/90 i.e. 55.5%). Chromosomes 9, 10, 14, 17, 18, 20 and 21 were more often involved in hyperdiploidy. Chromosome 21 duplication was present in 92% of the cases. Chromosomes 5, 15, 16, 17 and Y were less often involved (18-20%) in hyperdiploidy. About 44% of patients with hyperdiploidy had additional karyotypic abnormality of which TEL-AML1 was predominant (24%). Chromosome loss was rare and accounted for 20% of the cases only. We did not find any FLT3 mutation in our patients. CONCLUSION: In this study, the pattern of chromosome involvement in hyperdiploid karyotype of ALL patients is same as other studies except some chromosomes like 1, 6, 11, 12, 19 and 22 have some more frequent involvement than other studies. This study also showed the occurrence of TEL/AML1 fusion is more (19.8%) than other reports from India.

Molecular Pathogenesis of Multiple Myeloma: Clinical Implications.

Multiple myeloma is a malignancy of bone-marrow-localized, isotype-switched plasma cells that secrete a monoclonal immunoglobulin and cause hyperCalcemia, Anemia, Renal failure, and lytic Bone disease. It is preceded, often for decades, by a relatively stable monoclonal gammopathy lacking these clinical and malignant features. Both conditions are characterized by the presence of types of immunoglobulin heavy gene translocations that dysregulate a cyclin D family gene on 11q13 (CCND1), 6p21 (CCND3), or 12q11 (CCND2), a maf family gene on 16q23 (MAF), 20q11 (MAFB), or 8q24 (MAFA), or NSD2/FGFR3 on 4p16, or the presence of hyperdiploidy. Subsequent loss of function of tumor suppressor genes and mutations activating MYC, RAS, NFkB, and cell cycle pathways are associated with the progression to malignant disease.

Optical Genome Mapping Reveals the Complex Genetic Landscape of Myeloma.

Fluorescence in situ hybridization (FISH) on enriched CD138 plasma cells is the standard method for identification of clinically relevant genetic abnormalities in multiple myeloma. However, FISH is a targeted analysis that can be challenging due to the genetic complexity of myeloma. The aim of this study was to evaluate the potential of optical genome mapping (OGM) to detect clinically significant cytogenetic abnormalities in myeloma and to provide larger pangenomic information. OGM and FISH analyses were performed on CD138-purified cells of 20 myeloma patients. OGM successfully detected structural variants (SVs) (IGH and MYC rearrangements), copy number variants (CNVs) (17p/TP53 deletion, 1p deletion and 1q gain/amplification) and aneuploidy (gains of odd-numbered chromosomes, monosomy 13) classically expected with myeloma and led to a 30% increase in prognosis yield at our institution when compared to FISH. Despite challenges in the interpretation of OGM calls for CNV and aneuploidy losses in non-diploid genomes, OGM has the potential to replace FISH as the standard of care analysis in clinical settings and to efficiently change how we identify prognostic and predictive markers for therapies in the future. To our knowledge, this is the first study highlighting the feasibility and clinical utility of OGM in myeloma.

Clonal heterogeneity by fluorescence in situ hybridization in multiple myeloma: enhanced cytogenetic risk stratification.

Background: Multiple myeloma (MM) is a proliferation of monoclonal plasma cells that accumulate in bone marrow, leading to bone destruction and marrow failure. Cytogenetic analysis is a challenge in MM because of the low mitotic activity and the rapid loss of plasma cells viability in bone marrow culture. Adding mitogens such as interleukin 6 (IL6) is known to promote the in vitro growth of myeloma cell lines and enhance the fluorescence in situ hybridization application. This study aims to evaluate the prognostic impact of cytogenetic abnormalities detected by enhanced interphase fluorescence in situ hybridization (iFISH) technique in Egyptian MM patients. Results: Patients who had hyperdiploidy significantly presented with higher Hb level and lower calcium levels compared to non-hyperdiploid patients. They were staged as stage I and II by International staging system (ISS) and considered as standard risk showing better response to treatment. On the contrary, features associated with a worse outcome were patients having del 17p and those belonged to intermediate and high risk groups. Conclusion: In conclusion, adding interleukin 6 to MM cell culture promotes the in vitro growth of myeloma cells and enhances the successful application of FISH technique. A comprehensive FISH probe set investigating high, intermediate and low-risk cytogenetic abnormalities is needed for accurate risk stratification. Hyperdiploid-myeloma is a favorable risk genetic subtype of MM associated with rapid response to therapy compared to patients having del 17p, t(4;14), and other 14q rearrangements rather than t(11;14) and t(6;14).

Fish evaluation of additional cytogenetic aberrations and hyperdiploidy in childhood Burkitt lymphoma.

Beyond MYC rearrangement, Burkitt lymphoma (BL) often presents with additional aberrations. Biopsy touch imprints from 72 children with BL were tested with interphase fluorescence in-situ hybridization (i-FISH) for MYC, BCL2, BCL6, IGH, IGK and IGL rearrangements and copy-number aberrations involving 1q21/1p32, 7cen/7q31, 9cen/9p21, 13q14/13q34 and 17cen/17p13. Diploid status deviations were investigated with chromosome enumeration probes. MYC rearrangement was demonstrated in all cases. Additional aberrations included +1q (21/72:29.2%), +7q (14/72:19.4%), 13q- (14/72:19.4%), 9p-(6/72:8.3%) and hyperdiploidy (6/72:8.3%). Advanced clinical stage IV, +7q and 9p- were associated with shorter overall survival, with stage IV and +7q retaining prognostic significance on multivariate analysis. No relapse or death was reported among the hyperdiploid cases. This i-FISH investigation provides information on the genetic profile of BL and may prove valuable for patients with no karyotype analysis. Demonstration of hyperdiploidy could evolve research on clonal evolution pathways and probably identify a subgroup of children with favorable prognosis.