Chromosomal aberrations in 130 patients with multiple myeloma studied by interphase FISH: diagnostic and prognostic relevance

Implementation of cytogenomic microarray with plasma cell enrichment enables better abnormality detection and risk stratification in patients with plasma cell neoplasia than conventional cytogenetics and fluorescence in situ hybridization

The detection of chromosomal abnormalities is important in the diagnosis, prognosis and disease monitoring in plasma cell neoplasia (PCN). However, the gold standard diagnostic techniques of conventional cytogenetics (CC) and fluorescence in situ hybridization (FISH) are hampered by culture difficulties and probe availability. Cytogenomic microarray (CMA), however, is able to surmount such limitations and generate a comprehensive genomic profile with the implementation of plasma cell (PC) enrichment. In this study, we examined 89 bone marrow specimens with CC and FISH without PC enrichment, 35 of which were examined with CMA after PC enrichment. Results revealed that after PC enrichment, CMA was able to detect chromosomal abnormalities in 34 of 35 specimens tested (97.1%), compared to 21 and 32 specimens (60% and 91.4%, respectively) achieved by CC and FISH, respectively, which were similar to the abnormality detection rates among all 89 specimens (59.5% by CC and 92.1% by FISH). In addition, as the only technique capable of detecting copy neutral loss of heterozygosity (CN-LOH) and chromothripsis, CMA appears to be the most powerful tool in risk stratification as it successfully re-stratified 9 (25.7%) and 12 (34.3%) specimens from standard risk (determined by CC and FISH, respectively) to high risk. Based on the encouraging data presented by our study and others, we conclude that implementation of CMA with PC enrichment is of great value in routine clinical workup in achieving a more complete genetic profile of patients with PCN.

The amplification of 1q21 is an adverse prognostic factor in patients with multiple myeloma in a Chinese population

The prognostic heterogeneity of multiple myeloma (MM) is largely due to different genetic abnormalities. Cytogenetic analysis has revealed that most of MM harbor chromosome aberrations. Amplification of 1q21 is one of the most common chromosomal aberrations. Interphase fluorescence in situ hybridization was applied to detect the 1q21 amplification in 86 Chinese patients with newly diagnosed MM. Amp(1q21) was found in totally 40 of 86 (46.5%) cases, among which 29 with three copies of 1q21 and eleven with at least four copies of 1q21. Further analysis revealed a significant difference of overall survival and progression-free survival among the three arms (P<0.05). Bortezomib could not significantly improve the overall survival for patients with 1q21 amplification (P>0.05). These findings suggest that 1q21 amplification with four copies or more is prognostic factor for adverse outcomes of MM patients. Furthermore, chromosome 1q21 gains predicted a poor overall survival even in those receiving bortezomib-based regimens.

Retrospective evaluation of the clinical and laboratory data from 300 patients of various hematological malignancies with chromosome 3 abnormalities

This retrospective study was designed to evaluate the clinical and laboratory behaviors of chromosome 3 abnormalities by analyzing the morphological, cytogenetic, and follow-up data from 300 patients of various hematological malignancies with chromosome 3 abnormalities. From the results, trisomy 3, translocation (3q), and del(3) were the abnormal types most frequently observed (>10%) among the chromosome 3 abnormalities. In hematological malignancies, chromosome 3 abnormalities were most frequently seen in the patients with acute myeloid leukemia (AML) (24.7%) and myelodysplastic syndrome (MDS) (16%), followed by those with acute lymphocytic leukemia (ALL) (13.7%) and multiple myeloma (MM) (12.7%). In this series, genomic losses were the most frequent genetic abnormalities in AML, ALL, and hybrid acute leukemia (HAL) patients, whereas structural rearrangements were frequently seen in chronic myeloid leukemia (CML) and MDS patients, and genomic gains in MM, lymphoma and chronic lymphocytic leukemia (CLL) patients. Chromosome 3 abnormalities mainly occurred as a component of a complex abnormality (251/300) rather than a sole one (14/300). Survival analysis demonstrated a statistical difference between the patients with trisomy 3, who had a better prognosis, and patients with del(3), who had a worse prognosis in this series (P < 0.05). Abnormalities in chromosome 3 may imply an unfavorable outcome in CML and ALL.

Impact of genetic abnormalities on the prognoses and clinical parameters of patients with multiple myeloma

Background

We reviewed patients with multiple myeloma (MM) in order to assess the incidence of genetic abnormalities and their associations with clinical parameters, risk groups, and prognosis.

Methods

A total of 130 patients with MM were enrolled. The incidences of genetic abnormalities were determined in all patients. The relationships of the genetic abnormalities and clinical parameters were investigated. In addition, a survival analysis was performed.

Results

Abnormal karyotypes were detected in 42.3% (N=55) of the patients, and this was increased to 63.1% (N=82) after including the results determined with interphase FISH. Hypodiploidy was observed in 7.7% (N=10) of the patients, and all were included in the group with complex karyotypes (30.8%, N=40). The 14q32 rearrangements were detected in 29.2% (N=38) of the patients, and these most commonly included t(11;14), which was followed by t(4;14) and t(14;16) (16.2%, 11.5%, and 0.8%, respectively). Abnormal karyotypes and complex karyotypes were associated with disease progression markers, including low hemoglobin levels, low platelet counts, high plasma cell burden, high β2-microglobulin, and high international staging system stages. A high free light chain (FLC) ratio and FLC difference were associated with abnormal karyotypes, complex karyotypes, and higher plasma cell burden. Hypodiploidy and low platelet counts were significant independent prognostic factors and were more important in patient outcome than any single abnormality.

Conclusions

Genetic abnormalities were associated with disease progression markers and prognosis of MM patients.

IRF4 promotes cell proliferation by JNK pathway in multiple myeloma

Interferon regulatory factor 4 (IRF4) is a member of the interferon regulatory family, which plays an important role in many lymphoid and myeloid malignancies. In the current study, using immunohistochemical staining, we found that IRF4 only expressed in plasma cells in bone marrow biopsy samples of multiple myeloma. IRF4-positive patients displayed increased disease stage (Durie-Salmon stage, p = 0.026; and International Staging System, p = 0.005). Silencing IRF4 in myeloma cell lines could inhibit myeloma cells proliferation and induce myeloma cell apoptosis, partly by JNK/Jun pathway. These results demonstrate that IRF4 plays important roles in myelomagenesis and disease progression.

Conventional and molecular cytogenetic analyses in Turkish patients with multiple myeloma

OBJECTIVE

Multiple myeloma (MM) is characterized by the accumulation and proliferation of malignant plasma cells, secreting monoclonal immunoglobulins and genetic abnormalities in MM have implications for disease progression and survival. In the present study, we investigated the frequency of chromosomal abnormalities (CA) in Turkish patients with MM, using interphase FISH and CC and evaluated the relationship between the rearrangements detected, prognosis and stage of disease.

MATERIAL AND METHODS

We performed conventional cytogenetic and FISH studies in 50 patients to detect chromosome anomalies associated with MM. FISH probes were used to detect 13q14, 13q34, 17p13 deletions, IGH rearrangements, and monosomy and/or trisomy of chromosomes 5, 9, and 15.

RESULTS

CC studies could be performed in 32 of 50 cases and five patients (15.6%) showed chromosomal aberrations while 27 (84.3%) had normal karyotypes. By FISH, eighteen percent (9/50) of cases were found to be normal for all parameters evaluated. Eighty-two percent (41/50) of the patients were positive for at least one abnormality. Chromosome 13 anomalies were detected in 54% (27/50) of cases. The second most common aberration observed is chromosome 15 aberrations (50%).

CONCLUSION

Median survival rate was shorter in patients with one of the abnormalities including chromosome 13 aberrations, IGH rearrangements or P53 deletions. Chromosome 15 aberrations were significantly higher in patients with stage III disease (p=0.02). We conclude that FISH studies should be performed in conjunction with conventional cytogenetic analysis for prognosis in multiple myeloma patients.

Molecular cytogenetic aberrations in Tunisian patients with multiple myeloma identified by cIg-FISH in fixed bone marrow cells

Cytogenetic studies in multiple myeloma (MM) are hampered by the hypo-proliferative nature of plasma cells. In order to circumvent this problem, we have used a combination of immunolabeling of cytoplasmic Ig light chains (λ or κ) and FISH (cIg-FISH), which allowed a comprehensive detection of the most common and/or recurrent molecular cytogenetic aberrations on fixed bone marrow cells of 70 Tunisian patients. Translocations involving the chromosome 14q32 region were observed in 32 cases (45.7%), including 18 cases with a t(11;14), 8 cases with a t(4;14), and 2 cases with a t(14;16). Deletions of the 13q14 region (D13S319/RB1) were detected in 18.6%, and deletions of the 17p13 region (TP53) in 5.7% of the cases, respectively. Of all patients with a D13S319/RB1 deletion, 61.5% also carried a 14q32 translocation, whereas TP53 deletions were associated with a t(11;14) in 2 cases (50%) and a D13S319 deletion in 1 case (25%). Our results suggest that there is a correlation between the presence of 14q32 translocations and chromosome 13q14 deletions in MM patients and that cIg-FISH is more sensitive as compared to conventional karyotyping in detecting molecular cytogenetic abnormalities in this disease.

Diagnostic yield of bone marrow and peripheral blood FISH panel testing in clinically suspected myelodysplastic syndromes and/or acute myeloid leukemia: a prospective analysis of 433 cases

It is unclear how often and in what setting fluorescence in situ hybridization (FISH) panels for myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) provide additional information over metaphase cytogenetics alone. Furthermore, the usefulness of peripheral blood vs bone marrow FISH has also not been directly compared. We prospectively compared metaphase cytogenetics and FISH for -5/5q-, -7/7q-, +8, and 20q- in 433 cases of suspected MDS/AML. FISH testing was abnormal in 6 (14%) of 43 and 10 (19%) of 54 cases with fewer than 20 normal metaphases or no growth, respectively. FISH was only rarely abnormal in cases with 20 normal metaphases obtained (6/222 [2.7%]). Comparison of peripheral blood and bone marrow results in 48 cases showed abnormal peripheral blood FISH results in 18 (69%) of 26 cases with abnormal bone marrow FISH results and in 5 (23%) of 22 cases with normal bone marrow FISH results. These findings, the largest published comparison of FISH vs metaphase cytogenetics in MDS/AML, provide a rational strategy for FISH testing in peripheral blood and bone marrow.

Plasma cell labeling index correlates with deletion of 13q14 in multiple myeloma

Multiple myeloma (MM) is characterized by complex genetic and chromosomal abnormalities involving both numerical and structural aberrations, which have clinical prognostic value. The plasma cell labeling index (PCLI) is one of the most important prognostic factors in newly diagnosed MM, and indicates plasma cell proliferative capacity. In this study, we determined the PCLI and the deletion of 13q14, retinoblastoma-1 gene (RB-1), 1p13, and 17p13, 1q21 amplification, and IgH rearrangements in 42 newly diagnosed patients with MM. A high PCLI was observed in 18 patients (42.9%), and the del(13q14) was present in 25 patients (59.5%), del(RB-1) in 23 patients (54.8%), del(17p13) in eight patients (19.1%), amp(1q21) in 23 patients (54.7%), del(1p13) in 17 patients (40.5%), and IgH rearrangements in 28 patients (66.7%). We further detected the IgH translocation partners: t(11;14)(q13;q32), t(4;14)(p16;q32), and t(14;16)(q32;q23) in 19, 15, and five patients, respectively. The PCLI had a significant correlation with del(13q14) (p = 0.006), but no correlation with other chromosome abnormalities or clinical and laboratory features (p > 0.05). The PCLI was higher among patients with del(13q14), and patients with a high PCLI had a short time to disease progression. In conclusion, PCLI is a powerful and independent prognostic parameter in newly diagnosed MM, and correlates with del(13q14).

Clinical utility of FISH analysis in addition to G-banded karyotype in hematologic malignancies and proposal of a practical approach

Background

Fluorescence in situ hybridization (FISH) analysis can provide important information in the management of patients with hematologic malignancies. However, FISH performed in addition to G-banded karyotype can be labor-intensive and expensive. The aim of this study was to evaluate whether FISH gives additional information in the setting of adequate conventional cytogenetics in cases of hematologic malignancies.

Methods

Bone marrow aspirates were obtained from 135 patients at diagnosis (56 AML, 32 MDS, 20 ALL, and 27 MM) between 2005 and 2010. Interphase FISH was performed using the following probes: BCR/ABL1, AML1/ETO, PML/RARA, CBFB, MLL, EGR1, CEP8, and D7S486 for AML; CEP8, D20S108, EGR1, and D7S486 for MDS; BCR/ABL1, MLL, CDKN2A (p16), ETV6, and 6q21/c-myc for ALL; IgH, TP53, D13S25, IgH/CCND1, IgH/MAF, IgH/FGFR3, and 1q21/8p21 for MM. We compared the results of FISH with the corresponding aberrations identified by G-banded karyotype.

Results

Additional genetic aberrations detected by FISH (which were not identified by G-banded karyotype) were 4%, 9%, 50%, and 67% in AML, MDS, ALL, and MM, respectively. In ALL, CDKN2A and ETV6 FISH revealed additional genetic aberrations in 33% and 28% of cases, respectively. In MM, FISH was of benefit in detecting IgH, D13S25, TP53, and 1q21 rearrangements, not detected by G-banded karyotype (31%, 36%, 20%, and 40%, respectively).

Conclusion

These results suggest that performing FISH in addition to G-banded karyotype may contribute little additional genetic information in AML and MDS, whereas routine FISH analysis appears to be an efficient screening method in ALL and MM.

Expression and prognostic relevance of MAGE-C1/CT7 and MAGE-C2/CT10 in osteolytic lesions of patients with multiple myeloma

Cancer-testis (CT) antigens are promising targets for antigen-specific therapy of multiple myeloma (MM). Osteolytic lesions represent the most common clinical manifestation of myeloma and it is possible that osseous myeloma lesions differ from bone-infiltrating tumor cells with regard to the extent of CT antigen expression based on the epigenetic regulation of these genes. We, therefore, performed the first analysis of CT antigen expression in osteolytic lesions of myeloma patients to further define the diagnostic, prognostic, and therapeutic value of these proteins. Lytic bone samples were obtained from MM patients during surgical interventions and a tissue microarray was constructed. 105 bone samples and 24 bone marrow biopsies were stained immunohistochemically with antibodies against CT antigens MAGE-C1/CT7 and MAGE-C2/CT10 and Ki-67. MAGE-C1/CT7 and MAGE-C2/CT10 were frequently expressed in osteolytic lesions (46% and 54%) and bone marrow (75% and 54%). Expression of MAGE-C1/CT7 was significantly more frequent in patients with advanced stage of disease (p=0.023) and with a chromosomal deletion 17p13 (p53) (p=0.047). Samples with more than 75% MAGE-C1/CT7 expressing myeloma cells showed a higher proliferative rate (indicated by the expression of Ki67) than those with less than 25% MAGE-C1/CT7 expressing cells (p=0.011). Moreover, a content of ≥50% MAGE-C1/CT7 expressing myeloma cells in a sample was associated with reduced overall survival (p=0.013). Our results, therefore, suggest that expression of MAGE-C1/CT7 and MAGE-C2/CT10 in osteolytic lesions of myeloma patients can be used for diagnostic, prognostic, as well as immunotherapeutic purposes.

Bacterial artificial chromosome array-based comparative genomic hybridization using paired formalin-fixed, paraffin-embedded and fresh frozen tissue specimens in multiple myeloma

BACKGROUND

Multiple myeloma (MM) is a neoplasm of malignant plasma cells that often harbors many chromosomal aberrations. Currently, fresh frozen tissues (FT) are considered the most reliable for molecular genetic analysis; however, formalin-fixed, paraffin-embedded (FFPE) tissues are easily retrievable. Compared with conventional cytogenetics, bacterial artificial chromosome (BAC) array-comparative genomic hybridization (CGH) allows more sensitive detection of chromosomal abnormalities.

METHODS

The authors analyzed 7 paired FT and FFPE samples of bone marrow aspirate materials obtained from patients with MM in parallel to determine the efficacy of BAC array-CGH using FFPE.

RESULTS

Thirty-four aberrations were identified, including 29 that were observed in both sample types, yielding 85% concordance. Nonrandom anomalies, including gains on 7q, 9q, 15q, and 19p and losses on 8p and 13q, were observed in paired samples from at least 2 patients. To verify these results, fluorescence in situ hybridization (FISH) was performed using probes specific for 7q and 15q, and gains were observed in the 4 samples that were examined. Furthermore, 1 of 3 samples from patients who had monoclonal gammopathy of undetermined significance that were tested also carried gain on 7q, suggesting that this aberration may be an early transforming event.

CONCLUSIONS

The current results indicated that BAC array-CGH can be effective using FFPE samples and is a sensitive method for the identification of nonrandom chromosomal aberrations in MM.

Nonmyeloablative allografting for newly diagnosed multiple myeloma: the experience of the Gruppo Italiano Trapianti di Midollo

Despite recent advances, allografting remains the only potential cure for myeloma. From July 1999 to June 2005, 100 newly diagnosed patients younger than 65 years were enrolled in a prospective multicenter study. First-line treatment included vincristin, adriamycin, and dexamethasone (VAD)-based induction chemotherapy, a cytoreductive autograft (melphalan 200 mg/m(2)) followed by a single dose of nonmyeloablative total body irradiation and allografting from an human leukocyte antigen (HLA)-identical sibling. Primary end points were the overall survival (OS) and event-free survival (EFS) from diagnosis. After a median follow-up of 5 years, OS was not reached, and EFS was 37 months. Incidences of acute and chronic graft-versus-host disease (GVHD) were 38% and 50%, respectively. Complete remission (CR) was achieved in 53% of patients. Profound cytoreduction (CR or very good partial remission) before allografting was associated with achievement of posttransplantation CR (hazard ratio [HR] 2.20, P = .03) and longer EFS (HR 0.33, P < .01). Conversely, development of chronic GVHD was not correlated with CR or response duration. This tandem transplantation approach allows prolonged survival and long-term disease control in patients with reduced tumor burden at the time of allografting. We are currently investigating the role of "new drugs" in intensifying pretransplantation cytoreduction and posttransplantation graft-versus-myeloma effects to further improve clinical outcomes. (http://ClinicalTrials.gov; NCT-00702247.).

The RBCC gene RFP2 (Leu5) encodes a novel transmembrane E3 ubiquitin ligase involved in ERAD

RFP2, a gene frequently lost in various malignancies, encodes a protein with RING finger, B-box, and coiled-coil domains that belongs to the RBCC/TRIM family of proteins. Here we demonstrate that Rfp2 is an unstable protein with auto-polyubiquitination activity in vivo and in vitro, implying that Rfp2 acts as a RING E3 ubiquitin ligase. Consequently, Rfp2 ubiquitin ligase activity is dependent on an intact RING domain, as RING deficient mutants fail to drive polyubiquitination in vitro and are stabilized in vivo. Immunopurification and tandem mass spectrometry enabled the identification of several putative Rfp2 interacting proteins localized to the endoplasmic reticulum (ER), including valosin-containing protein (VCP), a protein indispensable for ER-associated degradation (ERAD). Importantly, we also show that Rfp2 regulates the degradation of the known ER proteolytic substrate CD3-delta, but not the N-end rule substrate Ub-R-YFP (yellow fluorescent protein), establishing Rfp2 as a novel E3 ligase involved in ERAD. Finally, we show that Rfp2 contains a C-terminal transmembrane domain indispensable for its localization to the ER and that Rfp2 colocalizes with several ER-resident proteins as analyzed by high-resolution immunostaining. In summary, these data are all consistent with a function for Rfp2 as an ERAD E3 ubiquitin ligase.