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Abstract Background: FLC is a valuable diagnostic tool to monitor response in patients with AL and oligosecretory MM. It is also prognostic in patients with MGUS. Its value in patients with non-oligosecretory myeloma has not been defined. Because of the short half-life of free-light chains, an early drop in free-light chain might be predictive for long term outcome post PBSCT. Methods: Between 8/1/03 and 12/10/04, 45 patients with multiple myeloma and abnormal FLC ratios (less than 02.6 or greater 1.65), who were undergoing PBSCT consented to have waste serum from routine post-transplant daily blood draws collected and frozen for future FLC analysis. The immunoglobulin FLC assay (Binding Site, U.K.) was run on samples collected from day +1 until patients were dismissed from our transplant center. Hematologic response was coded according to standard IBMTR criteria at approximately 3 months status post transplant (BJH 1998). Two types of immunoglobulin FLC response were coded: 50% reduction (FLC50) and 90% reduction (FLC90) of the difference of the involved and uninvolved FLC (Leukemia 2006). Two time periods of FLC response were analyzed: early (day 7); and delayed (day 19, range 13 to 24). Endpoints analyzed were overall response (>=PR), complete response rate (CR), progression free survival (PFS), and overall survival (OS). Results: The median age of the myeloma group was 59 years, and 53% were male. Thirty-three patients were monoclonal kappa, and 12 lambda. Forty-two percent were transplanted in response/plateau, 22% were primary refractory, and 36% relapsed disease. The overall hematologic response rate was 93% with a CR rate of 33%. Twenty-five patients have relapsed at a median of 14.2 months. Twelve patients have died, and median overall survival for the group has not been reached at a median follow-up of 24.6 months. Forty-nine and 58 percent of patients had early and delayed FLC90, respectively. Early FLC90, but not delayed FLC90, predicted for complete response (p<0.001). Neither early nor delayed FLC90 predicted for either PFS or OS. In addition, 89% and 96% of patients had an early and delayed FLC50, respectively. FLC50 at either time point did not predict for overall response, CR, PFS, or OS. Conclusion: Immunoglobulin free light chain responses are seen within the first weeks post high dose chemotherapy with peripheral blood stem cell transplant. A 90% reduction in FLC seen within the first seven days predicts for complete response. However, this does not yet translate into prolonged PFS or OS, but with longer follow-up separation of the survival curves may be seen.

Abstract Abstract 2868 Poster Board II-844 Background and Objective: In newly diagnosed multiple myeloma (MM), the combination of lenalidomide plus high-dose dexamethasone (RD) is superior to high-dose dexamethasone (Zonder JA et al, Blood 2007;110:77). Preliminary results show that lenalidomide plus low-dose dexamethasone (Rd) has better 2-year overall survival (OS) compared with RD (Rajkumar SV et al, J Clin Oncol 2008;26:8504). The addition of clarithromycin (Biaxin) to lenalidomide and low-dose dexamethasone (BiRd) has been investigated in a phase II study, demonstrating a high response rate and 2-year OS (Niesvizky R at al, Blood 2008;111:1101-1109). However, the additive value of clarithromycin is not known. No randomized trials have compared Rd versus BiRd, none are planned. The objective of this case–matched study was to compare the efficacy and the toxicity of BiRd vs Rd as initial therapy for newly diagnosed MM. Patients and methods: Data from 72 newly diagnosed MM patients treated at the New York Presbyterian Hospital–Cornell Medical Center, from December 2004 to December 2006, with BiRD, were analyzed. For comparison, an equal number of pair mates were selected among newly diagnosed patients seen at the Mayo Clinic who received Rd, from March 2005 to December 2008. Case matching was performed with respect to age, gender, and transplant status. Patients treated with BiRd received oral lenalidomide (25 mg/day, days 3-21 of cycle 1; days 1-21 of subsequent cycles); dexamethasone (40 mg days 1, 2, 3, 8, 15, 22 of cycle 1; days 1, 8, 15, and 22 of each subsequent cycle); clarithromycin (500 mg twice daily, from day 2 of cycle 1). Patients treated with Rd received oral lenalidomide (25 mg/day, days 1-21) plus low-dose dexamethasone (40 mg days 1, 8, 15, 22). In both groups patients were allowed to discontinue treatment to pursue transplant, but treatment until progression, relapse or unacceptable toxicity was permitted at the physician's discretion. Outcome was analyzed on an intention-to-treat basis. The Chi-square or the rank sum tests were used to compare variables. Time-to-event analysis was performed using the Kaplan-Meier method; comparisons were determined by the log-rank test and the Cox proportional hazards model. Results: Median duration of treatment was 11.8 months in the BiRd group vs 6 months in the Rd group. On intention-to-treat analysis, complete response was significantly higher with BiRd compared to Rd (45.8% vs 13.9%, respectively, p<0.001); similarly very good partial response (VGPR) or better was higher with BiRd (73.6% vs 33.3%, p<0.001). Rates of VGPR or better, after 6 months and 1 year of therapy, were significantly higher in BiRd patients. Both time-to-progression (TTP) (median 48.3 months vs 27.5 months; HR 0.51; 95% CI 0.25-1.06; p=0.071) and PFS (median 48.3 months vs 27.5 months, HR 0.50; 95% CI 0.25-0.98; p=0.044) were higher with BiRd. Median time to next treatment (TTNT) was not reached in BiRd group compared to 29.9 months in Rd patients (HR 0.37 95% CI 0.20-0.66, p<0.001). There was a trend toward better OS with BiRd, (3-year OS: 89.7% vs 73.0%), but the difference was not statistically significant (HR 0.48; 95% CI 0.17-1.37; p=0.170). Thirty-two patients in each group received transplant; median time to transplant was longer in BiRd group (13.5 vs 5.9 months). Results of survival, for patients who received transplant and patients who did not, were similar to those of the total population. On subset analysis, among patients presenting with International Staging System (ISS) stage I/II at diagnosis, TTP, PFS and TTNT were significantly longer in BiRd patients; no significant differences were found among patients with ISS stage III. Main grade 3-4 toxicities of BiRd were hematological, in particular thrombocytopenia (23.6% vs 8.3%, p=0.012); rate of neutropenia was similar between the 2 groups (19.4% vs 16.7%, p=0.665). Infections (16.7% vs 9.7%, p=0.218) and dermatological toxicity (12.5% vs 4.2%, p=0.129) were higher in patients who received Rd. Rate of venous thromboembolism was similar in the 2 groups (9.7% vs 12.5%, respectively in Rd and BiRd patients, p=0.596). Conclusion: Results of this case-control analysis suggest superiority of BiRd in terms of response rate and survival, compared with Rd, and suggest that there may be a significant additive value when clarithromycin is added to Rd. These data indicate the need for randomized prospective phase III studies to evaluate BiRd versus Rd in the treatment of MM. Disclosures: Off Label Use: research drug in combination to standard of care. Kumar:celgene: Research Funding; millenium: Research Funding; bayer: Research Funding; novartis: Research Funding; genzyme: Research Funding. Mark:celgene: Research Funding. Dispenzieri:celgene: Research Funding. Gertz:celgene: Honoraria; genzime: Honoraria; millenium: Honoraria; amgen: Honoraria. Leonard:celgene: Consultancy. Lacy:celgene: Research Funding. Witzig:celgene: Research Funding. Fonseca:medtronic: Consultancy; genzyme: Consultancy; celgene: Consultancy; amgen: Consultancy; BMS: Consultancy; otsuka: Consultancy. Greipp:celgene: Research Funding. Niesvizky:celgene: Research Funding, Speakers Bureau; Millenium: Research Funding, Speakers Bureau; Proteolix: Research Funding, data monitoring committee.

Abstract BACKGROUND: Bone marrow fibrosis might represent either a primary myeloid malignancy such as myelofibrosis with myeloid metaplasia (MMM) or a reactive phenomenon associated with other malignancies or inflammatory/infectious processes. The development of myelofibrosis in the context of a plasma cell dyscrasia is uncommon and incompletely understood from the standpoint of both pathogenesis and clinical implications. We sought to determine the origin and clinical ramifications of this phenomenon based on a consecutive series of patients with plasma cell disorders (PCD). METHODS: A retrospective search of institutional databases was performed for clinical cases of PCD with the concomitant observation of myelofibrosis. Bone marrow aspirates and trephines from the time of diagnosis of both PCD and myelofibrosis were reviewed. Clinical history was abstracted for clinical manifestations as well as disease course. DNA from archived cytogenetic pellets, when available, from the time of diagnosis, was screened for the presence of JAK2V617F. RESULTS: Among 7587 patients with a PCD seen over the last 30 years at our institution, 29 (0.3%) displayed concomitant myelofibrosis (median age 59 years, range 27–77; 52% males). The specific PCD was multiple myeloma in 25 patients, smoldering myeloma in 2, plasmacytoma in 1, and heavy chain disease in 1. Four patients (14%) had organomegaly and bone marrow histological features most consistent with MMM. Otherwise, myeloproliferative disorder (MPD)-characteristic features were infrequent and included leukocytosis and/or thrombocytosis in only 2 patients. None of the patients displayed thrombohemorrhagic complications. Archived DNA was available in 7 cases without either clinical or bone marrow histological evidence of a MPD and yet revealed the presence of JAK2V617F in 6 of the 7 cases (86%). In addition, one other patient without MPD phenotype displayed a monosomy 5 abnormality. To date, 2 patients, one with and one without a MPD phenotype underwent leukemic transformation. All other causes of death were related to PCD-associated complications. Median survival (Kaplan-Meier) for the patients with multiple myeloma was 50 months. Survival stratified by the myeloma international staging system (ISS) was similar or better than expected (published controls of 62, 44, and 29 months): median survivals for this series of 73, 51 and 37 months for stage I, II, and III disease, respectively. CONCLUSIONS: Myelofibrosis that accompanies a PCD often represents an underlying MPD and does not negatively impact the natural history of the associated PCD.

Abstract Background: Patients with AL and congestive heart failure have a median survival of less than one year. Methods: Between 1994 and 2005, 11 patients underwent sequential heart transplant followed by autologous peripheral blood stem cell transplant (SCT) for treatment of AL. Patients had heart dominant AL with minimal/no other organ impairment and no evidence of multiple myeloma. Results: Patients ranged in age from 35 to 63 years (median 54). All had biopsy proven amyloidosis and monoclonal protein detectable in serum (73%) or urine (100%). Free light chain assay was available prior to SCT in 6 and was abnormal in all. All patients presented with NYHA Class III or IV heart failure. All but two patients had no other organ involved at the time of heart transplant. One patient had his heart transplant at another facility and had renal involvement at the time of heart transplant. One patient had peripheral nerve involvement documented prior to heart transplant. Five patients had progression of amyloid to involve other organs by the time of SCT. These included: renal (6), peripheral nerve (2), macroglossia (3), gastrointestinal (2). The median time from diagnosis to heart transplant was 3 months (range 1 to 5). The median time from heart transplant to SCT was 8 months, (range 3 to 24). Conditioning chemotherapy consisted of melphalan 200 mg /m2 (6 patients) or melphalan 140 mg/m2 (5 patients). Two patients died of complications before day +100, (TRM of 18%). Hematologic remissions were seen in 8 and organ responses in 3. Five were unable to be evaluated for organ response due to the heart transplant. Three died from progressive amyloidosis at 66, 56.7, and 55 months following SCT. The median survival is 56.7 months from SCT. Six are alive with a median follow-up of 24 months, range 9 to 90 months. Among the 6 surviving patients, one patient relapsed and one patient has failed to improve, but 4 patients are in continued remission. One patient developed secondary myelodysplastic syndrome. Conclusions: Heart transplant followed by SCT is feasible and offers durable remissions for carefully selected patients with cardiac AL. Figure Figure

Abstract Chronic Idiopathic Bence Jones Proteinuria (first reported in 1982) is an asymptomatic plasma cell proliferative disorder that is associated with a risk of progression to symptomatic multiple myeloma (MM) or primary amyloidosis (AL). We defined it as the presence of a monoclonal light chain in the urine, absence of an intact immunoglobulin M protein (IgH expression) in the serum, fewer than 10% bone marrow plasma cells (if done), and no evidence of MM, AL or other related plasma cell proliferative disorders. Following approval by the Mayo Clinic Institutional Review Board, we searched a computerized database and reviewed the records of all patients who were seen at Mayo Clinic within 30 days of the recognition of a monoclonal light chain (Bence Jones protein) in the urine between 1960 and 1996. Patients found to have end-organ damage at diagnosis as the result of the plasma cell proliferative disorder (including MM or AL), received chemotherapy, or had a nephrotic syndrome were excluded. Follow-up included review of each subject’s medical record at Mayo Clinic as well as review of death certificates for patients who died. Patients were sent letters of inquiry if they had not visited Mayo Clinic in the preceding year. The risk of progression to MM and AL was compared to those expected on the basis of Surveillance, Epidemiology and End Results (SEER) rates for MM in Iowa and the prevalence of AL in Olmsted County, Minnesota. Two-hundred twenty-three patients fulfilled the criteria for Idiopathic Bence Jones Proteinuria during the 37-year period (1960 – 1996). The median age at diagnosis was 69 yrs (range, 36–90 yrs) and only 1% were < 40 years of age. Sixty-seven percent were male. The urine M protein ranged from unmeasurable to 4.7 g/24h. The median was 0.09 g/24h and only 8% were > 1 g/24h. Kappa light chain accounted for 57% while lambda was present in 43%. Eighty-one percent of patients died during follow-up. Twenty-six percent had a monoclonal light chain in the serum on immunofixation. Concentrations of uninvolved (normal, polyclonal or background) immunoglobulins were reduced in 45%. During 1408 person years of follow-up, 11 patients developed symptomatic MM (relative risk 28.5; 95% CI, 14.3 – 51.1) and an additional 9 patients developed AL (relative risk 61.8; 95% CI, 28.3 – 117.4). The cumulative probability of progression to active MM or AL was 7% at 5 yrs, 13.5% at 10 yrs., and 18% at 15 yrs. The factors evaluated with respect to predicting progression to MM or AL included sex, hemoglobin value, serum albumin, amount of urine M protein/24h, type of urine light chain (kappa or lambda), reduction of uninvolved (background) immunoglobulins, and elevation of serum calcium or creatinine. The amount of the urine M protein/24h was the only significantly predictive parameter for progression. As a continuous variable, a higher urine M protein was associated with an increased risk of progression (hazard ratio = 2.1 for a 1g increase, p=0.003). The amount of the urine M protein was also significant as a dichotomous variable. Patients who had a urine M protein ≥ 1g/24h had an increased risk of progression (hazard ratio = 3.6, p=0.007). We conclude that patients with Idiopathic Bence Jones Proteinuria are at risk for the development of MM or AL and need to be followed indefinitely.

Abstract Background: High dose therapy (HDT) and stem cell transplant has been shown to improve survival in patients with myeloma and remains the standard of care. However, the reported results of initial HDT in these patients reflect the combined effect of the initial therapy and the HDT. The contribution of HDT on its own is often difficult to analyze in this group of patients with varying degree of response to initial therapy. In this single institution retrospective study, we have analyzed the results of HDT in a group of patients with measurable disease at the time of HDT. Methods: We identified patients from our transplant database, who had measurable disease at the time of initiation of transplant as defined by a serum M protein of ≥ 1.0 g/dL, 24 hour urine M-protein ≥ 200 mg or a bone marrow plasma cell % of ≥ 30. Details regarding the clinical outcome were obtained from the database and from patient clinical records. Chi square test was used for comparison of nominal variables and t-test for continuous variables. Kaplan Meier analysis was used for comparing survival and Cox proportional hazards was employed to identify predictors of progression free and overall survival. Responses were defined by the EBMTR criteria, using the measurements at the time HDT and the lowest measurement obtained. VGPR required a 90% reduction in the serum M component with urine protein &lt; 100 mg/24 hours. Results: A total of 440 patients were studied; 271 (61.5%) of whom had a transplant within one year of their diagnosis. Among the 271 patients, 140 (52%) were in the initial plateau, 99 (36%) failed to achieve a PR to initial therapy and 32 (12%) were in their first relapse. Given the known differences in the outcome between these groups of patients, those receiving an early transplant were analyzed separately. The response rates included CR (24%), VGPR (7%), PR (52%), MR or less (17%) and among the late transplants CR (23%), VGPR (8%), PR (61%) and MR or less (8%). The median progression free survival was 23.6 mos and the overall survival from HDT was 62 mos. In a multivariate analysis, presence of cytogenetic abnormalities (RR: 2.5) and high plasma cell labeling index (≥ 1%) (RR: 2.4) at HDT and failure to achieve a CR or VGPR (RR: 1.7) were prognostic for decreased progression free survival post HDT. In a similar model, only high PCLI (RR: 2.8) and abnormal cytogenetics (RR: 2.5) at HDT predicted for poor overall survival after transplant. Conclusion: This study provides a sense of the contribution of HDT, independent of the initial therapy, by determining responses based on the immediate pre-transplant disease measurements and the best values observed post transplant. In this group of patients with residual measurable disease after the initial therapy, HDT therapy leads to complete responses in nearly a quarter of the patients and a VGPR in another 7%, an outcome associated with better progressin free survival. While measurements at transplant do not correlate strictly with response to initial therapy, the aim of this study was to understand the individual contribution of HDT in these patients. Thus some of the patients who would have been classified as having a partial response to induction and HDT may be classified as non-responders in this analysis. These numbers will provide a historical comparison for trials evaluating novel consolidation therapies for myeloma.

Abstract Background: An abnormal free light chain (FLC) indicating the presence of excess monoclonal FLC is associated with an increased risk of progression of monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) or related disorder. In addition, the risk of progression rises with increasingly abnormal FLC ratio, suggesting that the mechanism for markedly abnormal FLC ratios may be different compared to ratios closer to normal range. We hypothesized that as in light chain MM (in which IgH expression is completely lost), a more markedly abnormal FLC ratio is a marker for IgH translocations (TCs) involving 14q32. We tested this hypothesis using data obtained from gene expression profiling (GEP) to identify the presence of specific IgH TCs and correlating them to serum FLC ratio. Methods: We examined data from 128 GEPs from pts with MM (92), smoldering MM (13), MGUS (9) and primary amyloidosis (14). Presence of IgH translocations were identified using the specific probes for the partner chromosome TC sites, namely FGFR3/MMSET (4p16), cyclin D3 (6p21), cyclin D1 (11q13), c-maf (16q23), and mafB (20q12) as previously described. FLC estimation was carried out on stored serum samples from these patients using the serum FLC assay (FreeliteH, The Binding Site Limited, UK) performed on a Dade-Behring Nephelometer. Based on the established reference range, kappa/lambda FLC ratio <0.26 or >1.65 were defined as abnormal indicating the presence of monoclonal lambda and kappa FLC, respectively. The monoclonal LC isotype was considered the involved FLC isotype, and the opposite LC type as the uninvolved FLC type. Differential expression of genes was examined using Genespring 7.2 software. Results: Among the 92 pts with MM, 36 (42%) had evidence of one of the 5 primary IgH TCs: 20 pts with 11q13 (22%), 7 pts with 4p16 (8%), 4 pts with16q23 (4%), 3 pts with 20q12 (3%), and 2 patients with 6p21 (2%). Among the 11 pts with MM with an FLC ratio of > 1000, 8 (72%) had an IgH TC. The proportion of pts with an FLC ratio >1000 was significantly higher in pts with an IgH TCcompared to those without, 22% vs 5% respectively, P=0.02. The mean FLC ratio was 1728 (range; 1.6 to 31,008) in patients with an IgH TC vs. 412 (1–11340) for those without IgH TCs, P=0.09. Similarly in pts with MGUS, SMM or AL all three pts with a ratio > 50 had evidence of an IgH translocation. compared to 14/33 with lower ratio. The mean FLC ratio was 29 (range;1 to 209) in pts with an IgH TC vs. 9.1 (1–41) for those without IgH TCs, P=0.1. We correlated the results of FISH tests where available (122 of 128 pts) to determine the ability of GEP to identify IgH TCs. IgH translocation identified by the GEP could be detected on FISH in 42 of 47 patients (89%). Correspondingly, 61 of 75 patients (81%) without an IgH translocation on GEP had a similar result by FISH as well. We compared the GEP of MM pts with FLC ratio of >500 to the rest and identified 34 genes which were 2 fold differentially expressed between the two groups. Conclusion: By combining GEP data and serum FLC measurements, we show that very high FLC ratios is associated with IgH translocations. However, the correlation is not absolute, likely reflecting that markedly abnormal FLC ratios may be mediated through other mechanisms including increasing tumor load. To further explore this we analyzed differentially expressed genes between patients with high and low ratios and identified a set of 34 genes, which are currently being studied further.

Abstract Background: Autologous stem cell transplantation (SCT) improves survival in patients (pts) with multiple myeloma (MM). We have previously demonstrated that the degree of response at transplant does not impact on the outcome of transplant. However, newer induction regimens such as thalidomide and dexamethasone (Thal-Dex) result in higher response rates compared to previously used regimens such as single agent dexamethasone or vincristine, doxorubicin, and dexamethasone (VAD). We examined the outcome of SCT following three different induction therapies for newly diagnosed MM, namely VAD, single agent Dex, and Thal-Dex. Patients and Methods: 340 patients with MM who received their SCT within 12 mos of diagnosis (median 5.8, range 3–12) were studied. Patients receiving more than one induction therapy as well as those in whom thalidomide was added to dexamethasone for lack of response were excluded from the analysis. There were 105 pts in the VAD group, 140 in the Dex group and 95 in the Thal-Dex group. Responses were defined using standard criteria. Results: The study cohort consisted of 209 males (59%), with a median age of 57 years (range 30–76) at transplant. Baseline characteristics were similar in the 3 groups, except for lower age in the VAD group (median 55.8) compared to Dex (59.6) and Thal Dex (57.4) and shorter time to transplant in the Dex group (5.4 m) compared to VAD (6.4) and Thal Dex (5.9). Markers of disease activity pre-transplant, including B2M and marrow plasma cell percentage were higher in the Dex group compared to either VAD or Thal Dex. The proportion of patients with any response to induction therapy was lower in the Dex group compared to the other two. All pts in the Dex and the Thal-Dex groups received melphalan only conditioning compared to 70% in the VAD group, the rest receiving Melphalan/TBI. An objective response was achieved after SCT in 96%, 97%, and 98% of pts in the VAD, Dex and Thal-Dex groups respectively (P=0.8). A complete response to SCT was seen in 49% of patients in VAD group, 45% among those in the Dex group and 38% among those in the Thal Dex group (P=0.38). There was no difference in the median progression free survival after transplant (P=0.21) or overall survival from diagnosis (P=.34) between the three groups. The proportion free from progression at 2 years post transplant was 54%, 55% and 46% for Dex, VAD and Thal-Dex respectively. The proportion surviving at 4 years from diagnosis was 64%, 65.4% and 72% respectively for the three groups. Conclusion: We did not observe any difference in the response rates including complete responses to SCT in the three groups with nearly all pts in each group achieving a response. The progression free survival and overall survival appear to be comparable between the three groups. The results from initial therapy cannot be compared between the three regimens since the study population is restricted to patients reaching stem cell transplant. Within the limits of the study, there does not appear to be any long term impact of the initial therapy for the patients going onto an early stem cell transplant. Figure Figure

Abstract The oncogene c-maf is frequently over-expressed in multiple myeloma cell lines and patient samples and contributes to increased cellular proliferation in part by inducing cyclin D2 expression. Therefore, small molecules that inhibit c-maf and its targets could be useful chemical probes to better understand the role and regulation of this protein. We developed a high throughput chemical screen in NIH 3T3 cells stably over-expressing the promoter of the c-maf target cyclin D2 driving firefly luciferase. From a screen of 2400 off-patent drugs and chemicals, we identified 32 compounds that preferentially reduced cyclin D2 transactivation. Of these, 24 of the 32 hits belonged to the corticosteroid family of drugs. Indeed, the screen identified 24 of the 26 corticosteroids in the library. The most potent inhibitors were glucocorticoids such as dexamethasone. Mineralocorticoids such as fludrocortisone were weak hits, reflecting their weak glucocorticoid activity. The 24 glucocorticoids identified in this screen preferentially reduced cyclin D2 transactivation in the presence of c-maf. For example, the IC50 of dexamethasone was 11 ± 0.7 nM and >50 uM in NIH 3T3 cell with and without c-maf, respectively. Given the effects of glucocorticoids on c-maf in NIH 3T3 cells, we extended our investigation to multiple myeloma cell lines and demonstrated that nanomolar concentrations of the glucocorticoid dexamethasone reduced levels of c-maf protein and its target cyclin D2 within 6 hours of treatment. C-Maf was down regulated in isogenic MM1.S but not MM1.R cells respectively sensitive and resistant to dexamethasone. We also observed reductions in another c-maf target, beta integrin. Compared to cell lines RPMI 8226 and OCIMY5 that harbor the t(14;16) c-maf translocation, the concentration of dexamethasone required to reduce c-maf was approximately 50-fold lower in cell lines such as LP1 and OPM1 that lack the translocation but over-express c-maf. While dexamethasone reduced c-maf protein, no changes in levels of c-maf mRNA were detected. In both multiple myeloma and NIH3T3 cells, dexamethasone increased the ubiquitin-dependent destruction of c-maf. Finally, we linked glucocorticoids to c-maf ubiquitination by demonstrating that dexamethasone upregulated ubiquitin C mRNA at concentrations associated with the ubiquitination of c-maf. Moreover, ectopic expression of ubiquitin cDNA recapitulated the effects of dexamethasone and reduced levels of c-maf, suggesting that increased expression of ubiquitin C by dexamethasone is functionally important for dexamethasone’s effects on c-maf levels. Conclusion: a chemical biology screen identified glucocorticoids as c-maf dependent inhibitors of cyclin D2 transactivation. Glucocorticoids reduce c-maf by promoting its ubiquitination via the upregulation of ubiquitin C mRNA. This work provides new insights into the regulation of c-maf and has identified a novel mechanism by which glucocorticoids exert an anti-myeloma effect.

Translocations involving immunoglobulin (Ig) loci and chromosome 13 monosomy (Δ13) are frequent cytogenetic findings in multiple myeloma (MM). Similar chromosomal aberrations have been identified in the monoclonal gammopathy of undetermined significance (MGUS), but their prevalence and significance remain uncertain. Bone marrow from 72 patients with MGUS (n = 62) and smoldering MM (n = 10) was evaluated for translocations between the Ig heavy chain (IgH) and chromosomes 4, 11, and 16, translocations involving Ig light chain–lambda (IgL-λ, and Δ13. Fluorescence in situ hybridization (FISH) analysis was done on clonal plasma cells (PCs) detected by immunofluorescence (cIg-FISH) of the cytoplasmic light chain. We also studied cells for cyclin D1 and FGFR3 up-regulation by immunohistochemistry and immunofluorescence, respectively. Twenty-seven (46%) of 59 patients had IgH translocations, and 4 (11%) of 37 had an IgL-λ translocation. A t(11;14)(q13;q32) was found in 15 (25%) of 59 patients, a t(4;14)(p16.3;q32) in 9% of patients, and a t(14;16)(q32;q23) in 5% of patients. All patients with t(4;14)(p16.3;q32) tested (n = 3) had intense cytoplasmic fluorescence with an anti-FGFR3 antibody. PC nuclear staining of cyclin D1 was only observed in patients with t(11;14)(q13;q32); Δ13 was detected in the clonal PCs in 50% of patients. The percentage of abnormal PCs varied with any given abnormality. No obvious clinical or biologic correlations were associated with these chromosome abnormalities. Similar translocations are found in both MGUS and MM, including t(4;14)(p16.3;q32) and t(14;16)(q32;q23). Moreover, Δ13 is common in MGUS and unlikely to play a predominant role in the evolution of MGUS to MM.