scholarly journals High incidence of chromosome 13 deletion in multiple myeloma detected by multiprobe interphase FISH

Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1505-1511 ◽  
Author(s):  
John Shaughnessy ◽  
Erming Tian ◽  
Jeffrey Sawyer ◽  
Klaus Bumm ◽  
Reid Landes ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Poor Prognosis ◽  
Plasma Cells ◽  
Suppressor Gene ◽  
Homozygous Deletion ◽  
Cell Labeling ◽  
Fish Analysis ◽  
Chromosome 13 ◽  
High Incidence ◽  
Homozygous Deletions

Abstract Multiple myeloma (MM) is a hypoproliferative malignancy yielding informative karyotypes in no more than 30% of newly diagnosed cases. Although cytogenetic and molecular deletion of chromosome 13 is associated with poor prognosis, a MM tumor suppressor gene (TSG) has not been identified. To localize a minimal deleted region of chromosome 13, clonotypic plasma cells from 50 consecutive patients with MM were subjected to interphase fluorescence in situ hybridization (FISH) analysis using a panel of 11 probes spanning the entire long arm of chromosome 13. Whereas chromosome 13 abnormalities were absent in plasma cells from 25 normal donors, 86% of patients with MM demonstrated such aberrations. Heterogeneity, both in deletion frequency and extent, was confirmed by simultaneous FISH with 2 chromosome 13 probes. Deletion hot spots were noted at D13S272 (70%) and D13S31 (64%), 2 unlinked loci at 13q14. Homozygous deletions at these loci occurred in 12% (simultaneously in 8%) of the cases. Molecular deletions were found in all 14 patients with morphologic deletions, in 21 of 24 with uninformative karyotypes, and 8 of 12 patients with karyotype abnormalities lacking chromosome 13 deletion. Homozygous deletion of any marker was noted in 4% with low and in 36% with higher plasma cell labeling index greater than 0.4% (P = .01). The absence of increasing deletion incidence and extent with therapy duration suggests that the observed lesions are not induced by treatment. The high incidence and extent of chromosome 13 deletions require the correlation of specific deletion(s) with poor prognosis. These analyses will provide valuable guidance toward cloning of an MM-TSG.

scholarly journals High incidence of chromosome 13 deletion in multiple myeloma detected by multiprobe interphase FISH

Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1505-1511 ◽  
Author(s):  
John Shaughnessy ◽  
Erming Tian ◽  
Jeffrey Sawyer ◽  
Klaus Bumm ◽  
Reid Landes ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Poor Prognosis ◽  
Plasma Cells ◽  
Suppressor Gene ◽  
Homozygous Deletion ◽  
Cell Labeling ◽  
Fish Analysis ◽  
Chromosome 13 ◽  
High Incidence ◽  
Homozygous Deletions

Multiple myeloma (MM) is a hypoproliferative malignancy yielding informative karyotypes in no more than 30% of newly diagnosed cases. Although cytogenetic and molecular deletion of chromosome 13 is associated with poor prognosis, a MM tumor suppressor gene (TSG) has not been identified. To localize a minimal deleted region of chromosome 13, clonotypic plasma cells from 50 consecutive patients with MM were subjected to interphase fluorescence in situ hybridization (FISH) analysis using a panel of 11 probes spanning the entire long arm of chromosome 13. Whereas chromosome 13 abnormalities were absent in plasma cells from 25 normal donors, 86% of patients with MM demonstrated such aberrations. Heterogeneity, both in deletion frequency and extent, was confirmed by simultaneous FISH with 2 chromosome 13 probes. Deletion hot spots were noted at D13S272 (70%) and D13S31 (64%), 2 unlinked loci at 13q14. Homozygous deletions at these loci occurred in 12% (simultaneously in 8%) of the cases. Molecular deletions were found in all 14 patients with morphologic deletions, in 21 of 24 with uninformative karyotypes, and 8 of 12 patients with karyotype abnormalities lacking chromosome 13 deletion. Homozygous deletion of any marker was noted in 4% with low and in 36% with higher plasma cell labeling index greater than 0.4% (P = .01). The absence of increasing deletion incidence and extent with therapy duration suggests that the observed lesions are not induced by treatment. The high incidence and extent of chromosome 13 deletions require the correlation of specific deletion(s) with poor prognosis. These analyses will provide valuable guidance toward cloning of an MM-TSG.

Screening of Homozygous Deletions Identifies Key Deregulated Genes and Pathways in Multiple Myeloma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2474-2474
Author(s):  
Paola E. Leone ◽  
Brian A. Walker ◽  
Nicholas J. Dickens ◽  
Matthew W. Jenner ◽  
David C. Johnson ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Copy Number ◽  
Plasma Cells ◽  
Homozygous Deletion ◽  
Fragile Sites ◽  
Expression Array ◽  
Expression Arrays ◽  
Genomic Regions ◽  
Homozygous Deletions ◽  
Mapping Arrays

Abstract Homozygous deletions (HD) are important in cancer cell lines and have a non-random distribution in the genome. We have determined the frequency and distribution of HD, along with the genes affected, in 84 presenting multiple myeloma cases using the Affymetrix 500K SNP GeneChip mapping arrays. Initially we took a highly sensitive approach identifying regions with a copy number (CN) <1.0 in at least 4 adjacent SNPs. The analysis was done both manually, in dChip, and using an in-house algorithm. To reduce the complexity of the data generated we removed deletions that only occurred in one sample and further filtered the data using U133 Plus 2.0 expression array analysis. Genes passed expression filtering criteria by having a lower expression than the median expression of all samples. HD in plasma cells occur during IgH and IgL chain rearrangements and were used as internal controls to validate our approach. We found that regions of homozygous deletion were not randomly distributed. At the CN<1.0 level, we identified 1761 regions containing 6650 genes. After expression filtering 129 genes were identified (with an additional 116 genes which did not have expression array probesets) which fell in chromosomal regions 1p, 6q, 8p, 11q, 12p, 13q, 14q, 16q, 20q, and 22q, which are also the regions that most frequently have loss of heterozygosity (LOH). The distribution of deletions was even between different myeloma molecular groups. We then applied a more stringent copy number cut-off of 0.65 and identified 18/84 cases with HD (21%, median size 18 kb) and most cases had only one homozygous deletion. In this analysis the number of genomic regions falls to 29 spread over 10 chromosomes, including 241 genes of which only 20 genes survived expression filtering. Of these regions 3 are in known fragile sites and only 1p, 11q, 13q, and 22q showed HD containing genes with a decreased expression. Although deletions were seen on chromosome 13, none involved the RB1 locus. Several microRNA were also noted to be deleted on chromosomes 6, 13, and 22 indicating that these may also be important in myeloma and are being explored further. The NF-kB pathway inhibitors BIRC2 and BIRC3, on 11q, were homozygously deleted in 4 cases as were the neighbouring loci ANGPTL5 and TMEM123. Interestingly, the 11q region was the exception to the rule that HD occur only in regions of LOH. The most frequent regions of homozygous deletion involved CDKN2C (p18) and FAF1 on 1p32.3, which were deleted in 6 cases (CN<1.0). In addition we have demonstrated that deletion of this region is an important prognostic marker (median survival 19 months vs 33 months). We and others have suggested that p18 is the important event at this locus but in this study when stringent criteria (CN<0.65) were applied more frequent deletions were found at the FAF1 locus. To define the critical lesion we carried out mutation and methylation analysis on both these genes and did not find any abnormalities at p18 and are using this approach to analyse FAF1. FAF1 is potentially relevant to myeloma as it is a regulator of NF-kB which also induces apoptosis via the FAS pathway. Loss of FAF1 could enable cells to tolerate DNA damage better than when it is intact. We have attempted to differentiate these two roles further through correlation with downstream deregulated genes using global expression arrays.

Loss of Spleen Visualization on Whole-Body Diffusion-Weighted Imaging in Patients with Multiple Myeloma Is Associated with Poor Prognosis and High Tumor Burden

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3797-3797
Author(s):  
Toshiki Terao ◽  
Youichi Machida ◽  
Ukihide Tateishi ◽  
Takafumi Tsushima ◽  
Kentaro Narita ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Diffusion Weighted Imaging ◽  
Poor Prognosis ◽  
Tumor Volume ◽  
Plasma Cells ◽  
Myeloma Cell ◽  
Stage Iii ◽  
Whole Body ◽  
Cell Infiltration ◽  
Group A

Abstract Introduction Multiple myeloma (MM) is caused by the proliferation of monoclonal malignant plasma cells in the bone marrow (BM). Imaging has played a major role in visualizing myeloma lesions, assessing tumor volume, and predicting the prognosis. Recently, we reported that the total diffusion volume (tDV), assessed using a pretreatment whole-body diffusion-weighted imaging (WB-DWI), was associated with a high BM plasma cells (BMPCs) and a poor prognosis in patients with MM (Terao. et al., Eur Radiol 2021). During that study, we unexpectedly found the frequent absence of a spleen signal in patients with MM and its reappearance after treatment. Therefore, this study aimed to investigate the association between spleen visualization changes on WB-DWI and myeloma tumor load and prognosis in patients with MM. Methods The data of 96 consecutive patients with symptomatic newly-diagnosed MM (NDMM) at Kameda Medical Center from January 2016 to December 2020, 15 consecutive patients with smoldering MM (sMM), and two autopsied spleens of patients with PC dysplasia were retrospectively reviewed. All patients underwent at least one WB-DWI prior to treatment. The detail of WB-DWI was previously reported (Terao. et al., Eur Radiol 2021). "Loss of spleen visualization" (LSV) was defined as a visual loss of the spleen in maximum intensity projection on the WB-DWI (Fig1). The spleen-to-spinal cord (SC) ratio (SSR) was used in each regions-of-interest (ROI) to compare the signal intensity. The spleen ROIs were defined as non-overlapping ROIs of 30-50 pixels. The SC ROI was the largest ROI without overhanging in the image depicting the maximum size of the spleen. This study was approved by the institutional review board and conducted in accordance with the Declaration of Helsinki. All participants provided informed consent. Results The median patient age was 75.5 years and 81 patients (84.4%) were 65 years or older. Almost all patients (n=91) received proteasome inhibitors (PIs) as remission induction therapy and 33 patients received autologous stem-cell transplantation (ASCT). LSV was observed on the WB-DWI of 56/96 (58.3%) patients with NDMM and in one patient with sMM (1/15, 6.7%). Patients with NDMM and LSV had a higher median BMPC infiltration as assessed by CD138-immunohistochemistry (80.0% vs. 50.0%, p<0.001), a higher median tDV (540.2 mL vs. 137.0 mL, p=0.003), higher rate of ISS stage III (p<0.01), a lower SSR (0.36 vs. 0.96; p<0.001), and lower tDV (540.2 mL vs. 137.0 mL; p=0.003) than those without LSV. The three-year PFS (p=0.27) and three-year OS (p=0.021) were lower in patients with NDMM with LSV (PFS: 51.2% and OS: 72.5%) than in patients without LSV (PFS: 63.4% and OS: 100%). Next, we investigated the spleen signal change of patients who underwent WB-DWI twice or more during treatment (n=74). Of 42 out of the 74 patients with LSV at diagnosis, the spleen during treatment became visible on 31/42 (73.8%) patients. Representative patients with various spleen signal changes during treatment are shown in Figure 3 as group A (n=32; patients without LSV at diagnosis and during treatment), group B (n=31; patients who had LSV at diagnosis but the spleen reappeared after treatment), and group C (n=11; patients who had LSV at diagnosis, and despite treatment response, did not regain the spleen signal). Patients in group C showed significantly worse three-year PFS and OS (not available due to early events) than those in group A and B, even after excluding patients who did not achieve partial response or worse (n=11) (Fig1). In the multivariate analysis, the group C retained its prognostic significance for both PFS (hazard ratio [HR], 1.98, 95% confidence interval [CI] 1.00-3.90, p = 0.049) and OS (HR, 5.16, 95% CI 1.27-21.0, p = 0.022) even after adjustment for age over 70 years and the revised-ISS stage III. At last, to investigate the pathological cause of LSV, we reviewed two patients who underwent autopsies, who had both received WB-DWI within 3 months before their deaths (Fig1). One patient showed diffuse myeloma cell infiltration in the spleen and the other showed the amyloid deposition without myeloma cell infiltration. Conclusion This study showed that LSV and a low SSR on pretreatment WB-DWI are correlated with a high tumor volume and poor prognosis. As patients with LSV during treatment had very poor prognosis, the relationships between LSV and other variables should be investigated. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals Poor prognosis in multiple myeloma is associated only with partial or complete deletions of chromosome 13 or abnormalities involving 11q and not with other karyotype abnormalities

Blood ◽  
1995 ◽  
Vol 86 (11) ◽  
pp. 4250-4256 ◽  
Author(s):  
G Tricot ◽  
B Barlogie ◽  
S Jagannath ◽  
D Bracy ◽  
S Mattox ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Poor Prognosis ◽  
Chromosomal Abnormalities ◽  
Multivariate Regression Analysis ◽  
Significant Variable ◽  
Chromosome 13 ◽  
Reactive Protein ◽  
Dismal Prognosis ◽  
Prognostic Implications ◽  
Beta 2 Microglobulin

Chromosomal abnormalities have major biologic and prognostic implications in leukemias. Cytogenetic information in typically hypoproliferative multiple myeloma (MM) is limited because of difficulties in obtaining analyzable metaphases. In this study, karyotypes and other known prognostic factors were analyzed in 155 newly diagnosed MM patients, entered on an intensive treatment program with two autotransplants. Complete remission (CR), event-free (EFS) and overall survival (OS) were analyzed using standard statistical methods. Abnormal cytogenetics were found in 39% of patients and were associated with a significantly lower CR rate (27% v 48%; P = .008). EFS and OS were inferior in patients with either partial or complete deletion of chromosome 13 or 11q abnormalities (“unfavorable” karyotype) when compared with the remaining patients (P < .001) who, as a group, had a similar prognosis irrespective of cytogenetic findings, ie, inevaluable, normal, or abnormal but without an “unfavorable” karyotype. The patients with abnormalities of both chromosomes 11 and 13 had a dismal prognosis with median EFS and OS of only 11 and 12 months, respectively. Significant associations were noted between an “unfavorable” karyotype and IgA isotype, elevated levels of beta-2 microglobulin (B2M, > or = 3 mg/L) and age > 60 years. On multivariate regression analysis, the absence of an “unfavorable” karyotype was the most significant variable associated with prolonged EFS and OS (P = .0001 and .0002, respectively). Other independent favorable variables were age less than 60 years, C-reactive protein (CRP) < or = 0.4 mg/dL and bone marrow plasmacytosis < or = 50% before treatment. On a multivariate analysis without cytogenetics, these same three standard parameters were identified as the only favorable variables. Patients not having all three standard favorable variables had a significantly lower CR rate (P = .03), EFS (P = .0001), and OS (P = .002) if an unfavorable karyotype was detected. We conclude that, in this program of uniformly treated MM patients, a poor prognosis was associated predominantly with abnormalities of chromosomes 11 and 13.

Both hypodiploidy and deletion of chromosome 13 independently confer poor prognosis in multiple myeloma

2002 ◽  
Vol 118 (4) ◽  
pp. 1041-1047 ◽  
Author(s):  
Athanasios B.-T. Fassas ◽  
Tray Spencer ◽  
Jeffrey Sawyer ◽  
Maurizio Zangari ◽  
Choon-Kee Lee ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Poor Prognosis ◽  
Chromosome 13

PTEN Gene Deletions in Patients with Multiple Myeloma.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4889-4889
Author(s):  
Xiao Ying Qi ◽  
A. Keith Stewart ◽  
Hong Chang
Keyword(s):  
Multiple Myeloma ◽  
Plasma Cells ◽  
Progression Free Survival ◽  
Myeloma Cell ◽  
Suppressor Gene ◽  
High Dose Chemotherapy ◽  
Pten Gene ◽  
Allelic Loss ◽  
High Dose ◽  
13Q Deletion

Abstract PTEN, a tumor suppressor gene, negatively regulates the anti-apoptotic action of akt phosphorylation. Allelic loss or mutation of this gene has been detected in many solid tumors and more recently in human myeloma cell lines (HMCLs). Expression of PTEN has resulted in growth inhibition and apoptosis of a HMCL, suggesting that it may play a role in the pathogenesis of multiple myeloma (MM). However, the PTEN status in tumor cells from patients with MM has not been determined. Using a triple staining method combining staining for cytoplasmic light chains and fluorescence in situ hybridization (FISH) with chromosome 10-centromere and PTEN-gene specific probes, we analyzed clonal plasma cells from 71 patients with MM, 10 with plasma cell leukemia (PCL) and 10 HMCLs. Hemizygous PTEN deletions were detected in 4 of 71 (5.6%) MM patients, 2 of 10 (20%) PCLs, and 2 of 10 (20%) HMCLs. The percentages of clonal plasma cells containing PTEN deletions ranged from 21–90% (median, 56%). Three of the 4 patients with PTEN deletions were detected at diagnosis with stage III disease (Duire-Salmon) and 1 was detected at relapse. Two patients had IgG kappa, 1 IgG lambda and 1 free lambda light chain. To correlate the PTEN status with other known genetic abnormalities in MM, we investigated 4 MM and 2 PCLs with PTEN deletions using FISH for chromosome13q, p53 status, translocations t(11;14), t(4;14) and t(14;16). One MM had a 13q deletion, 1 PCL had a t(11;14), and the other PCL had a t(14;16), a 13q deletion and a p53 deletion. All 4 MM patients with hemizygous PTEN deletions received melphalan based high-dose chemotherapy and autologous stem cell support. Their median overall survival (OS) was 48.1months, and progression free survival (PFS) was 42.8 months as compared to patients without PTEN deletions (OS, not reached, PFS, 25.8 months) (p=0.51 for OS, p=0.67 for PFS). Our results indicate that PTEN deletions are uncommon in MM patients and therefore unlikely represent a primary event for MM. PTEN deletions appear to occur in the advance stage of the disease, and are more frequently involved in PCL or HMCLs suggesting that deletions of PTEN may be associated with disease progression in a subset of MM.

Up-Front Thalidomide-Dexamethasone (THAL) and Double Autologous Transplantation (Double TX) for Multiple Myeloma: Comparison with Double TX without Added Thalidomide and Prognostic Implications of Chromosome 13 Deletion and Translocation t(4;14).

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3081-3081 ◽  
Author(s):  
Michele Cavo ◽  
Nicoletta Testoni ◽  
Carolina Terragna ◽  
Elena Zamagni ◽  
Paola Tacchetti ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Autologous Transplantation ◽  
Lower Probability ◽  
Fish Analysis ◽  
Primary Therapy ◽  
Cytogenetic Abnormalities ◽  
Chromosome 13 ◽  
Prognostic Implications ◽  
Intent To Treat

Abstract Aim of the present sudy was to evaluate the benefit of novel agents combined with conventional therapies in multiple myeloma (MM), with particular emphasis on patients (pts) carrying adverse cytogenetic abnormalities. For this purpose, we analyzed a series of 142 pts who received thalidomide-dexamethasone (thal-dex) and double autologous transplantation (double Tx). By study design, thal-dex was administered from the outset until the second autologous Tx. On an intent-to-treat basis, stringently defined (immumofixation negative) complete remission (CR) rate following double Tx and thal-dex was 54%. This value was significantly higher (P=0.0009) compared to the 33% observed in a comparable series of 129 pts who received double Tx without thal-dex. In comparison with these latter patients, addition of thal-dex to double Tx significantly prolonged PFS (median: 31 vs 42 months; P=0.04) and did not adversely affect survival after post-transplant relapse (P=0.7). All 142 pts included in the study were investigated at baseline for the presence of chromosome 13 deletion [del(13)] by FISH analysis and of t(4;14) using a RT-PCR assay. An analysis on an intent-to-treat basis performed according to the presence or absence of these cytogenetic abnormalities revealed that the probability to respond (more than 90% reduction in M protein concentration) to primary therapy with thal-dex for 94 pts who carried both del(13) and t(4;14) was significantly lower compared to that of 69 pts with del(13) alone (12% vs 41%, respectively; P=0.012) and of 18 pts with t(4;14) alone (12% vs 50%, respectively; P=0.006). The lower probability of response to first-line thal-dex therapy conferred by the presence of both del(13) and t(4;14) was completely offset by subsequent application of double Tx and thal-dex. Indeed, on an intent-to-treat basis, the probability to attain a very good partial response or CR for pts with both del(13) and t(4;14) positivity was 68% compared to 80% for pts with both del(13) and t(4;14) negativity (P=0.1). With a median follow-up of 24 months, the 3-year projected probabilities of OS and PFS were 80% and 59%, respectively (intent-to-treat). The presence or absence of t(4;14) had no significant impact on the 3-year projected probability of OS (80.12% vs 80.42%, respectively; P=0.3). Furthermore, an analysis of pts who actually received thal-dex and double Tx showed that curves of OS and EFS were almost superimposable among pts who carried or lacked both del(13) and t(4;14). Indeed, the 3-year projected probability of OS for pts with both these cytogenetic abnormalities was 92% compared to 88% for pts who were negative for both del(13) and t(4;14); (P=0.7); the corresponding figures for EFS were 70% vs 77%, respectively (P=0.9). These results suggest that thal-dex combined with double Tx may overcome the unfavourable prognosis conferred by del(13) and t(4;14). A longer follow-up is required before definite conclusions can be drawn.

Chromosome 1p21 Deletion Defines a Subgroup of Multiple Myeloma with Poor Clinical Outcomes Independent of del (13q), del(p53), t(4;14) or 1q21 Amplification.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2475-2475
Author(s):  
Hong Chang ◽  
Connie Qi ◽  
Allan Jiang ◽  
Wei Xu ◽  
Trieu Young ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Risk Factor ◽  
Genetic Risk ◽  
Plasma Cells ◽  
Prognostic Significance ◽  
Suppressor Gene ◽  
Autologous Stem Cell Transplant ◽  
Cell Transplant ◽  
Median Percentage ◽  
Chromosome 1Q

Abstract Amplifications involving chromosome 1q and deletions involving 1p are frequent events in multiple myeloma (MM). The pathogenesis and clinical significance of these anomalies is largely unknown but CKS1B amplification at 1q21 detected in 30–40% of MM patients is associated with disease progression. As karyotyping and SNP based mapping analysis identify a minimal common deletion region involving the 1p21 locus, we used FISH combined with cytoplasmic light chain detection (cIg-FISH) to investigate the prevalence and prognostic significance of del(1p21) in a cohort of 186 MM patients undergoing autologous stem cell transplant. CIg-FISH detected hemizygous 1p21 deletions in 18% of the cases. The median percentage of clonal plasma cells harboring del(1p21) was 55% (range 20–95%). The presence of 1p21 deletions was strongly correlated with CKS1B amplification (p=0.004), t(4;14) (p= 0.027), and del(p53) (p=0.04), but not with del(13q) or t(11;14). There was no association between del (1p21) and other biological factors including age, gender, Hb, albumin, C-reactive protein, beta-2 microglobulin level, isotype or bone marrow plasmacytosis. Patients with 1p21 deletions had significantly shorter progression-free (median 10.5 vs. 25.4 months, p=0.0001) and overall survivals (median 33.9 months vs. not reached, p=0.001) than those without such deletions. On multivariate analysis, del(1p21) was an independent risk factor for progression free (p&lt; 0.0001) and overall survivals (p=0.0005) after adjusting for other genetic risk factors including del(13q), del(p53), t(4;14) and CKS1B amplification. Our results indicate that del(1p21) is a novel genetic risk factor and warrant inclusion of this genetic aberration in the risk-stratification of MM. Further studies are required to identify candidate tumor suppressor gene(s) at the 1p21 locus and explore their role in the molecular pathogenesis of MM.

Loss of KDM6A/UTX Function Is a Common Event in a Mouse Model of Multiple Myeloma, Human Cell Lines and Patients.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 606-606
Author(s):  
Jonathan J Keats ◽  
Marta Chesi ◽  
Esteban Braggio ◽  
Stephan Palmer ◽  
Angela Baker ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Myeloma ◽  
Mouse Model ◽  
Gene Expression Profiling ◽  
Cell Lines ◽  
Expression Profiling ◽  
Homozygous Deletion ◽  
Recurrent Event ◽  
Comparative Genomic ◽  
Homozygous Deletions

Abstract Abstract 606 Multiple myeloma is a complex malignancy with multiple underlying genetic events. Our group has spent considerable effort over the last 15 years to elucidate the genetic underpinnings of myeloma. Most recently, we used array-based comparative genomic hybridization (aCGH) as a discovery tool in 62 myeloma patients and 46 myeloma cell lines. In that preliminary screen using the Agilent 44B aCGH platform (∼70kb resolution) we identified a diverse array of abnormalities, which resulted in constitutive activation of the NF-kB pathways. That initial analysis concentrated on the 43 genes we identified as potential targets of the 13 homozygous deletion events detected in the patient samples. A pathway analysis of these genes revealed a single pathway involving TRAF3, TRAF2, BIRC2, BIRC3, and CYLD. This first analysis focused exclusively on abnormalities present in the patient samples as we worried some abnormalities identified exclusively in the cell lines might not be relevant to the pathogenesis of myeloma in patients. However, several abnormalities were equally or more frequent overall but occurred exclusively in cell lines including CDKN2C (14 samples), CDKN1B (4 samples), KDM6A/UTX (4 samples), RB1 (3 samples), TP53 (3 samples). Given the fact that KDM6A/UTX deletions were as frequent as many of the best-described tumor suppressors it seemed like a good candidate but in the absence of patient events or a known function at the time it was not prioritized for further study. Recently, as part of the Multiple Myeloma Research Consortium (MMRC) Genomics Initiative, we have completed the analysis of a cohort of 250 myeloma patient samples by aCGH using the Agilent 244A aCGH platform (∼15kb resolution) and gene expression profiling using the Affymetrix U133Plus2.0 genechip. In this cohort with a significantly improved aCGH platform we identified 17 genes that are recurrently inactivated by homozygous deletions including DIAPH2 (15 samples), CDKN2C (14 samples), TRAF3 (11 samples), CYLD (8 samples), BIRC2/3 (7 samples), KDM6A/UTX (6 samples), and RB1 (5 samples). Based on the significant improvement in resolution and data quality achieved with the Agilent 244A aCGH platform we rescreen all of the cell lines on this improved platform. This significantly changed the frequency of several homozygous deletions in this population with the most frequently targeted genes now being CDKN2C (20 samples), KDM6A/UTX (13 samples), DIAPH2 (7 samples), RB1 (4 samples), TP53 (4 samples), CDKN1B (4 samples), and TRAF3 (4 samples). Moreover, as part of the genomic characterization of a spontaneous myeloma mouse model that we have developed, Vk*-Myc, we have identified recurrent (∼50%) homozygous deletions of Kdm6a/Utx. Therefore, one of the genes most commonly targeted by a homozygous deletion in human and mouse myeloma is KDM6A/UTX. In late 2007 after we had identified the first patients with KDM6A/UTX deletions it was shown that UTX is a functional histone demethylase that removes methyl groups from histone H3 lysine 27 (H3K27me). Given the high incidence of deletions and the fact that MMSET, the overexpressed target gene of t(4;14) in myeloma, is predicted to methylate H3K27, H3K36, and/or H4K20 by evolutionary conservation we developed the hypothesis that myeloma is characterized by abnormalities that result in excessive H3K27me (typically a repressive chromatin mark). Given the extensive whole genome sequencing occurring in the MMRC genomics initiative we elected to focus our resequencing efforts on the cell lines exclusively. These studies identified an additional 4 samples with LOH and an inactivating mutation bringing the total percentage of inactivated cell lines to 33%. Clearly, in the expanded patient and cell line cohorts the inactivation of KDM6A/UTX is not independent of MMSET overexpression suggesting they may act independently or synergistically. We are currently attempting to identify the genes controlled by KDM6A/UTX inactivation to better understand the functional consequences of this highly recurrent event. However, in the mouse model unlike the patient or cell lines, the gene expression profiling has identified a gene expression signature that differentiates UTX inactivated and functional samples suggesting an oncogenic function of inactivation. Disclosures: No relevant conflicts of interest to declare.

High Trip13 and Low P31 Comet Cause Drug Resistance and Poor Prognosis In Multiple Myeloma

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3820-3820
Author(s):  
Yi Tao ◽  
Zhimin Gu ◽  
Ye Yang ◽  
Hongwei Xu ◽  
Xiaojing Hu ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Drug Resistance ◽  
Cell Lines ◽  
Poor Prognosis ◽  
Caspase 3 ◽  
Plasma Cells ◽  
Myeloma Cell ◽  
Newly Diagnosed ◽  
Caspase 9 ◽  
Over Expression

Abstract Background We have recently established that increased chromosomal instability (CIN) signature is linked to drug resistance and poor outcome in multiple myeloma (MM) and other cancers. Thyroid Hormone Receptor Interactor 13 (Trip13), one of the 56 drug-resistant genes, plays a key role in chromosomal recombination and structure development during meiosis and has been reported to be increased in some malignancies including lung cancer, prostate cancer and breast cancer. In this study, we investigated how important Trip13 is in myelomagenesis and progression. Materials and Methods Gene expression profiling (GEP) was analyzed on plasma cells from 22 healthy donors, 44 patients with monoclonal gammopathy of undetermined significance (MGUS), 351 patients with newly diagnosed multiple myeloma, and 9 human myeloma cell lines, as well as on 36 sequential samples at diagnosis, pre-1st, pre-2nd and post-2nd autologous stem cell transplantation (ASCT). Over-expression and knock-down experiments of Trip13 were performed on myeloma cell lines by lentivirus transfection. Cell viability was assessed by trypan exclusion assay. Western blots were used to detect the expression of Trip13, P31 comet, caspase-8, caspase-9, caspase-3 and PARP, and checkpoint related proteins MAD2 and CDC20 in Trip13 overexpressed or Trip13 shRNA-transfected myeloma cells. Results Sequential GEP samples showed that Trip13 expression increased in 8 of 9 patients after chemotherapy and ASCT compared to the samples at diagnosis strongly suggesting that increased Trip13 is associated with drug resistance. Trip13 was already significantly increased in MGUS patients, newly diagnosed MM patients and MM cell lines compared with normal plasma cells. Furthermore, Trip13 was significantly higher in high-risk MMs than in low-risk MMs and increased Trip13 was linked to an inferior event-free survival (EFS) (p<0.01) and overall survival (OS) (p<0.01) in 351 newly diagnosed MMs. In contrast, the Trip13-interacting gene P31 comet was down-regulated in high-risk MMs and high expression of P31 was associated with good outcome. Interestingly, patients with high Trip13 and low P31 comet have the worst outcome compared to patients with only one of these, suggesting the interaction of Trip 13 and p31 has a synergistic effect on MM progression. Transfection of Trip13 into ARP1 and OCI-My5 cells significantly increased cell proliferation, while knock-down Trip13 in OCI-My5, H929, RPMI8226 cells inhibited cell growth and induced MM cell apoptosis with increases of cleaved caspase-8, caspase-9, caspase-3 and PARP. Mechanistic studies showed that Trip13 over-expression decreased P31comet and MAD2 expression by western blotting, but increased CDC20. Conclusions The association of increased Trip13 and decreased p31 is a good biomarker for MM drug resistance and poor prognosis. Our results also show Trip13 and P31 comet could be potential targets to overcome drug resistance in MM. Disclosures: No relevant conflicts of interest to declare.

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