ALBERT

Description: The interest around the graphene family of materials is constantly growing due to their potential application in biomedical fields. The effect of graphene and its derivatives on cells varies amongst studies depending on the cell and tissue type. Since the toxicity against non-adherent cell lines has barely been studied, we investigated the effect of graphene and two different graphene oxides against four multiple myeloma cell lines, namely KMS-12-BM, H929, U226, and MM.1S, as well as two non-Hodgkin lymphoma cells lines, namely KARPAS299 and DOHH-2. We performed two types of viability assays, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide conversion) and ATP (adenosine triphosphate detection), flow cytometry analysis of apoptosis induction and cell cycle, cell morphology, and direct interaction analysis using two approaches—visualization of living cells by two different systems, and visualization of fixed and dyed cells. Our results revealed that graphene and graphene oxides exhibit low to moderate cytotoxicity against cells, despite visible interaction between the cells and graphene oxide. This creates possibilities for the application of the selected graphene materials for drug delivery systems or theragnostics in hematological malignancies; however, further detailed studies are necessary to explain the nature of interactions between the cells and the materials.

Description: Background:Novel insights into the biology of myeloma cells have led to the identification of relevant prognosis factors.Cytogenetic abnormalities (CA) has become one of the most important prognostic factors, and the presence of t(4;14), t(14;16) or del(17p) are associated with poor prognosis. Although there are some reports indicating that 1q gains may be considered as a poor-risk feature, the information is not uniform. Furthermore, there are important controversies about whether or not novel agents-based combinations are able to overcome the poor prognosis of CA. In the relapse setting, the combinations including proteasome inhibitors and immunomodulatory drugs have shown to improve, and some of them to overcome, the outcome of patients with high-risk CA. Here we report a preplanned analysis, in a series of elderly newly diagnosed myeloma patients included in the Spanish GEM2010 trial and receiving VMP and Rd, in a sequential or alternating approach, in order to evaluate the influence of CA by FISH on the response rate and outcome. Patients and methods: 242 pts were randomized to receive a sequential scheme consisting of 9 cycles of VMP followed by 9 cycles of Rd or the same regimens in an alternating approach (one cycle of VMP alternating with one Rd, up to 18 cycles. VMP included the IV administration of weekly bortezomib (except in the first cycle that was given twice weekly) at 1.3 mg/m2 in combination with oral melphalan 9 mg/m2 and prednisone 60 mg/m2once daily on days 1-4. Rd treatment consisted on lenalidomide 25 mg daily on days 1-21 plus dexamethasone 40 mg weekly. FISH analysis for t(4;14), t(14;16), del(17p) and 1q gains was performed at diagnosis according to standard procedures using purified plasma cells. Results: In 174 out of the 233 patients evaluable for efficacy and safety, FISH analysis at diagnosis were available and two groups were identified: high-risk group (n= 32 patients with t(4;14) and/or t(14;16) and/or del(17p)) and standard-risk group (n=142 patients without high-risk CA). The rates of CA was similar in both treatment arms. Response Rates (RR) were no different in the high-risk vs standard-risk groups, both in the sequential (74% vs 79% RR and 42% vs 39% CR) and alternating arms (69% vs 86% RR and 39% vs 38% CR). After a median follow-up of 51 months, high-risk patients showed shorter PFS as compared to standard risk in the alternating arm (24 versus 33 months, p=0.03) and this also translated into a significantly shorter OS (38.4m vs not reached, p=0.002). However, in the sequential arm, high-risk and standard-risk patients showed similar PFS (29.5 months vs 31.5 months, p=0.9) and OS (46m vs 63m, p=0.1). This beneficial effect observed in the sequential arm applied to both t(4;14) or del(17p). As far as 1q gains is concerned, 151 patients had 1q information and 76 of them had 1q gains (50.3%), defined as the presence of more than 3 copies in at least 10% of plasma cells. The rate of 1q gains was well balanced in both sequential and alternating arms. The ORR was similar in patients with or without 1q gains (83% vs 80%) as well as the CR rate (45% vs 31%), and no differences were observed between sequential and alternating arms. Patients with or without 1q gains had a similar PFS (36 months vs 29 months) and 4-years OS (63% vs 68%) in the whole series and no differences were observed between the sequential and alternating arms. This effect has been observed in patients with 1q gains as isolated CA and the outcome was slightly but not significantly worse when 1q gains were present plus either t(4;14) and/or del17p. Conclusions: The total therapy approach including VMP and Rd administered in a sequential approach is able to overcome the poor prognosis of the presence of high-risk CA in elderly patients with newly diagnosed MM. The presence of 1q gains has no impact in the PFS and OS of elderly patients treated with VMP and Rd. Disclosures Mateos: Janssen, Celgene, Amgen, Takeda, BMS: Honoraria. Martínez-López:Novartis: Honoraria, Speakers Bureau. Oriol:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Paiva:Celgene: Honoraria, Research Funding; Janssen: Honoraria; Takeda: Honoraria, Research Funding; Sanofi: Consultancy, Research Funding; EngMab: Research Funding; Amgen: Honoraria; Binding Site: Research Funding.

Description: Introduction:SMM is an asymptomatic and heterogeneous plasma cell disorder. The Spanish Myeloma Group demonstrated that patients at high risk of progression benefit from early treatment with Rd. In addition, our preliminary results of the curative approach (GEM-CESAR) showed encouraging results (Mateos ASH 2017). Aim: The primary end-point was to evaluate the Minimal Residual Disease negative (MRD-ve) rate by next generation flow (NGF) after induction and ASCT and the sustained MRD-ve rate at 3 and 5 yrs after ASCT as secondary end-points. Our aim was to increase the MRD -ve rate from 34% (reported in NDMM patients after VTD and ASCT) to 50%. As all patients have completed induction and ASCT, we report the results of the primary end point, efficacy and safety after induction and ASCT. Methods: In this phase II single arm trial, 90 SMM patients at high-risk of progression (〉50% at 2 yrs), younger than 70 yrs and transplant candidates were included. The high risk was defined by the presence of both ≥PC 10% and MC ≥3g/dL (Mayo criteria) or ifonly one criterion was present, patients must have a proportionof aberrant PCs within the total PCsBM compartment by immunophenotypingof 95% plus immunoparesis (Spanish criteria). Asymptomatic MM patients with any of the three biomarkers recently included into the definition of active MM were allowed to be included. Induction therapy consisted on six 4-weeks cycles of KRd in which K was given at dose of 36 mg/m2twice per week plus R at dose of 25 mg on days 1-21 and dexamethasone at dose of 40 mg weekly. Melphalan at dose of 200 mg/m2followed by ASCT was given as intensification therapy and three months later, patients received two KRd consolidation cycles followed by maintenance with R at dose of 10 mg on days 1-21 plus dex at dose of 20 mg weekly for up to 2 yrs Results: Between June 2015 and June 2017, the 90 SMM patients at high risk of progression were recruited. Twenty-eight pts (32%) shared at least one of the new biomarkers predicting imminent risk of progression to MM. The primary end point of the trial was met, since 55% of the patients who completed induction and ASCT achieved MRD -ve by NGF (sensitivity 3 x 10-6). Upon analyzing the results after induction, 88 patients completed the 6 induction cycles and were evaluable for response (two patients early discontinued): the ORR was 98% including 41% of ≥CR (32% sCR and 9% CR) and 41% of VGPR rate. Two patients were mobilization failures and one patient rejected ASCT. Two additional patients experienced biological progression before ASCT and went off the study. Eighty-three patients, therefore, proceeded to HDT-ASCT and were evaluable at day +100: the ORR was 100% including ≥CR in 63% of the patients (51% sCR and 12% CR) and VGPR rate in 23%. The MRD-ve rate increased from 31% after induction to 55% with the ASCT. No differences in outcome have been observed according neither to the definition of high risk (Mayo or Spanish model) nor ultra high risk SMM. Concerning toxicity, during induction, G3-4 neutropenia and thrombocytopenia were reported in 5 (6%) and 10 pts (11%), respectively. G3-4 infections were the most frequent non-hematological AE observed in 16 pts (18%), followed by skin rash in 8 pts (9%). One patient reported G1 atrial fibrillation and another cardiac failure secondary to respiratory infection. Three patients reported hypertension (G2 in two and G3 in one). Thirteen patients required lenalidomide dose reduction whilst carfilzomib was not reduced in any patient. In four patients, dexamethasone was reduced. In all but two of the pts, PBSC collection was successful with a median of 4.10 x 106/Kg CD34 cells collected. All patients engrafted. Consolidation and maintenance phases are ongoing. After a median follow-up of 17 months (5-36), 94% of patients remain alive and free of progression and 97% of them alive. Three patients experienced biological progression and discontinued the study: one of them was refractory to the rescue therapies and died and the other two are receiving rescue therapies. One additional patient died early during induction due to a massive ischemic stroke unrelated to the treatment. Conclusions: Although longer follow-up is required, this "curative strategy for high risk SMM" continues being encouraging with an acceptable toxicity profile. The study has met its primary endpoint. The depth of response improved over the treatment: 63% of patients who completed induction and ASCT achieved ≥CR with a MRD-ve rate of 55%. Disclosures Mateos: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees. Rodriguez Otero:Takeda: Consultancy; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Clínica Universidad de Navarra: Employment. Ocio:AbbVie: Consultancy; Pharmamar: Consultancy; Seattle Genetics: Consultancy; Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; BMS: Consultancy; Takeda: Consultancy, Honoraria; Sanofi: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Mundipharma: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Array Pharmaceuticals: Research Funding. Oriol:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Rios:Amgen, Celgene, Janssen, and Takeda: Consultancy. Rosinol:Janssen, Celgene, Amgen, Takeda: Honoraria. Alegre:Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Puig:Janssen: Consultancy, Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Takeda: Consultancy, Honoraria. De La Rubia:Ablynx: Consultancy, Other: Member of Advisory Board. García Mateo:Binding Site: Research Funding; Amgen: Honoraria; Celgene: Honoraria. Bladé:Janssen: Honoraria. Lahuerta:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. San-Miguel:Novartis: Honoraria; Janssen: Honoraria; BMS: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Sanofi: Honoraria; Roche: Honoraria.

Description: Multiple myeloma (MM) pathogenesis has been explained for many years by the cancer biology dogma introduced by Peter Nowell: first, a single plasma cell would be immortalized by an error in the immunoglobulin genes rearrangement process; then, a progressive stepwise acquisition of somatic cell mutations would induce a sequential selection and domination by the fittest clone. In line with this idea of “myeloma stability”, SNP arrays studies in diagnostic-relapse paired samples have revealed the presence of common clonal characteristics. Biologically, the M-protein remains usually constant across MM evolution and further, the variable domain of the rearranged immunoglobulin heavy chain genes (or CDR3 region) has been used as a patient-specific myeloma fingerprint in minimal residual disease (MRD) studies. However, massive genome studies with Next Generation Sequencing (NGS) have challenged this concept, showing a significant intraclonal heterogeneity at diagnosis with the possible presence of several clonal progenitors or tumor-initiating cells. In this study, we have characterized and compared the CDR3 region in 52-paired samples from 26 MM patients aiming: 1) to assess mono-clonality in MM evolution through the analysis of the CDR3 sequence and, 2) to validate ASO RQ-PCR approaches for MRD in MM, based on the constancy and specificity of the CDR3 region. Samples were obtained at diagnosis and progression (19 pairs) or at 2 different timepoints of progressive disease (7 pairs). Median time between sampling was 2 years. M-protein subtype remained stable in all pairs but 1, associated with a light-chain escape phenomenon. All samples proceeded from bone marrow (BM) except for 2 pairs, composed by BM and extramedullary disease (spleen and testes). Two major cytogenetic changes were identified: increased 13q14 deletion (from 7 to 54%) in 1 pair and increased 17p (p53) deletion (from 5 to 87%) in a further one. Treatments administered between sampling included most of the current approaches used in MM (data not shown). Genomic DNA isolation, PCR amplification and sequencing were performed following conventional methods. Germline VH, DH and JH segments were identified by comparison with public databases. CDR3 region was first identified in all samples and then compared between the two samples in the 26 pairs: the sequence of nucleotides was constantly identical in each pair, including those associated with major cytogenetic changes, a light-chain escape, extramedullar vs. BM infiltration and relapsed (and therefore, treatment selected) vs. refractory disease. Therefore, we can first conclude that the main tumor clone in MM retains a specific signature across all stages of disease evolution that allows the identification of samples as evolutionary related. This major clone signature is not modified by clinical or biological changes in the disease nor under different treatment pressures and would thus identify disease relapse and progression. Our results have also a clear impact on the validity of molecular MRD techniques. The high rate of complete responses (up to 50-60%) currently achieved in MM has prompted the use of new techniques for disease assessment. Today, ASO RQ-PCR, based on the use of specific primers and probes complementary of the VDJH rearrangement, continues to be the most sensitive approach. One pitfall of this technique would be the potential instability of PCR targets over time, which would induce false negative results. In B-cell precursor ALL, this is estimated to happen in 30-40% of cases but has not been deeply evaluated in MM yet. With the present study, we can also conclude that the junction region of the VDJH rearrangement in MM constantly identifies the myeloma cells responsible for relapse and therefore can be used as a reliable target for MRD assessment by ASO RQ-PCR and more recently, by NGS methods. If the CDR3 region remains stable, the novel concept of clonal tiding in MM should not be interpreted as a poly- or oligoclonal but subclonal. In MM, tides can be subclonal, but the ocean remains monoclonal. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Disease control at five years would be a desirable endpoint for elderly multiple myeloma (MM) patients; however, the percentage of cases reaching this objective as well as the biomarkers to predict it, are not well defined. Objective and design: In order to gain further insight about long-term disease control (〉5 years progression-free) in elderly MM we have analyzed a homogeneous population of 435 newly-diagnosed transplant-ineligible (TNE) patients enrolled in two consecutive Spanish clinical trials (GEM2005MAS65, GEM2010MAS65), that included both proteasome inhibitors and immunomodulatory drugs. Results: Amongst the 435 patients included in this post-hoc study, only 18.8% remained alive and progression-free after five years of initiating treatment. Noteworthy, in these patients the overall survival (OS) rate at 10-years was 69.4%, as compared to 11.4% for those patients progressing during the first five years (p〈 0.001). Baseline variables significantly associated with long-term progression free survival in the univariate analysis were younger age, ISS 1, R-ISS 1, hemoglobin ≥ 12g/dl, normal LDH, and standard-risk cytogenetic abnormalities and the presence of a monoclonal gammopathy of unknown significance (MGUS)-like immunophenotypic profile in the bone marrow. Complete responses (CR) and minimal residual disease (MRD) negativity were also associated with long-term progression free survival. In the multivariate analysis, an hemoglobin level ≥12g/dl (OR 2.61; 95% CI 1.47 - 4.61, p=0.001) and a MGUS-like immunophenotypic profile in the bone marrow (OR 3.33; 95% CI 1.30 - 8.54, p=0.002) were the two baseline variables significantly and independently associated with a higher probability of long-term disease-free survival. When the depth of response (including MRD) was included in the logistic regression model, Hb level ≥12g/dl (OR 2.18; p=0.010) and the MGUS-like signature (OR 4.99, p

Description: Introduction VDJH usage description in B-cell hematological malignancies has brought new insights into the clonal differentiation and clinical implications for certain pathologies, improving patients' care, although no correlation has been made in MM. We present the largest-to-date VDJH gene repertoire analysis in MM, consisting in biological and clinical data from 413 patients. This database was used to comprehensively investigate the characteristics of VDJH rearrangements: gene segment usage, somatic hypermutation (SHM), CDR3 characterization, and immunoglobulin stereotyped clusters assessment. We also investigated the potential relationship of these molecular features with the outcome. Methods Newly diagnosed MM patients were included in the study. All were managed according to the recommendations of the GEM-PETHEMA Spanish MM group, including the inclusion of most patients in the GEM2000 and GEM2005 schemes. Monoclonal assessment was carried out with FR1 VH-JH amplification, following the BIOMED-2 methods. Moreover, 113 cases were also analyzed by NGS using the LymphoTrack IGH FR1 assay (Invivoscribe Tech, San Diego, CA). VDJH usage and mutational status were analyzed with IMGT-V-Quest. ClustalX2.0 was used to perform clustering analysis with CDR3 regions from our cohort and 1117 additional sequences obtained from IMGT/LIGM-DB corresponding to unique rearrangements from both normal and tumor human B cells. Molecular and clinical data were used to perform survival studies. Results The overall VDJH detection rate was 92.5% (382/413), including 376 patients with only one detectable rearrangement, five with a biallelic rearrangement, and one with a biclonal rearrangement, also detectable by flow cytometry. Thus, 388 rearrangements where detected: 362 were productive, and 26 unproductive. Gene segments were identified in productive rearrangements. VH repertoire in MM reflected its normal counterpart, with IGHV3 being the predominant selected family, followed by IGHV4, IGHV1, IGHV2 and IGHV5. IGHD and IGHJ segment usage showed a skewed distribution, with IGHD2 and IGHD3 families accounting for 55.5% of cases, and IGHJ4 and IGHJ6 accounting for 70.8%. SHM level could be identified in 349/362 productive sequences (mean: 9.16%, SD 3.95) with statistically significant differences between certain IGHV families, namely IGHV2 was less hypermutated than IGHV1 or IGHV4. We could also collect other rearrangement features: nucleotide addition by TdT appeared in 92.5% for N1 and 88.6% for N2, with evidence of exonuclease activity in all cases. CDR3 mean length was 16±4 aminoacids (median 15, range 6-29), with preference for Gly, Ala, Asp, Tyr (~10% each one). The R/S mutation ratio was 2.39 for CDRs versus 1.74 for FWRs, showing the high influence of antigen selection over the former. No stereotyped clusters were found in our cohort. Relationship between these finding and clinical evolution was done through univariate and multivariate analyses. A shorter Progression-Free Survival (PFS) related to well-known clinical factors: presence of plasmacytomas, poor performance status or ISS stages, response to therapy, and poor-risk cytogenetics (p

Description: Abstract 810FN2 Increasing evidence shows that a small fraction of MM patients (pts) treated with high-dose therapy followed by autologous stem cell transplantation achieve long-term remission. Interestingly, this is not restricted to pts in complete response (CR), since those that revert to a monoclonal gammopathy of undetermined significance (MGUS) profile may also achieve long-term remission, despite the persistence of residual myeloma plasma cells (PCs). These results suggest that in addition to the anti-myeloma therapy, other factors may play a role in the control of the disease. Herein, we used 8-color MFC for detailed characterization of the structural components of the immune system and hematopoietic precursor cells (HPC) in paired bone marrow (BM) and peripheral blood (PB) samples from 26 MM patients in long-term disease control (LTDC): 9 in continuous CR and 17 who reverted to an MGUS profile and that subsequently showed stable disease without treatment for ≥5 years (median of 9 years; range, 5–19). As controls, paired BM and PB samples from 23 newly-diagnosed MGUS and 16 MM pts, together with 10 healthy adults (HA), were studied in parallel. In all BM and PB samples the distribution of the major T- (CD4, CD8, Tregs and γδ), NK- (CD56dim and CD56bright) and B-cell subsets (Pro-B, Pre-B, naïve and memory), in addition to normal PCs, dendritic cell (DC) subsets (plasmacytoid, myeloid and monocytic), monocytes, and CD34+ HPC (myeloid and lymphoid), were studied. The percentage and absolute count of each cell population was analysed in the BM and PB, respectively. Comparison of the two groups of MM pts with LTDC (9 CR vs. 17 MGUS-like) showed similar (p〉.05) cellular profiles in PB and BM, except for an increased number of BM and PB normal PCs in CR patients (P≤.04). Consequently, for all subsequent analyses, LTDC myeloma pts were pooled together. When compared to HA, patients with LTDC had increased numbers of CD8 T-cells and CD56dim NK-cells in both the BM and PB (p≤.03 and p≤.01, respectively). Despite this, the distribution of BM and PB CD4, CD8 and γδ T-cells among LTDC patients was similar (p〉.05) to that of both newly-diagnosed MM and MGUS cases; in contrast, BM and PB Tregs were significantly decreased vs newly-diagnosed MM (P=.03) and MGUS (P=.04). Regarding B-cells and normal PCs, LTDC patients showed increased numbers of BM B-cell precursors (both Pro-B and Pre-B cells) and normal PCs vs. newly diagnosed MM (P≤.05), but not MGUS, together with increased numbers of naïve B-cells vs. both MM and MGUS pts (P≤.01); all such cell populations returned to levels similar (p〉.05) to those of HA. As expected, this also included the number of CD34+ B-cell HPC which was increased among patients who achieved LTDC vs MM (p=.02), at levels similar (p〉.05) to those of MGUS and HA. Regarding DC, LTDC patients showed normal DC numbers in PB (but with higher PB myeloid-DC numbers vs. MM; p=.02), in association with decreased numbers of plasmacytoid DC and increased monocytic-DC in the BM vs. HA (p≤.04). No differences were found for the numbers of BM and PB monocytes. In summary, here we investigated for the first time the immune cell profile of MM patients who achieve long-term disease control. Our results show that, as newly-diagnosed MM, patients that achieve long-term disease control also show increased numbers of cytotoxic T-cells and CD56dim NK-cells; however, in contrast to newly-diagnosed MM, among LTDC patients such increase is associated with lower numbers of T-regs and an almost complete recovery of the normal PC, B-cell precursor and naïve B-cell compartments both in BM and PB. Further investigations on the activation and functional status of these cell populations are warranted.MO (%)/SP (cels./μl)HA N= 10MGUS N= 23MM N= 16LTDC-MM N= 26T cells9.588110.6117313113711926    CD4+4.85004.6624^6*5085463    CD8+3.7∼216∼4.63865.32645.3431    TCR γδ.2426.3230.2428.3421    Treg.4137.4141^.54*38.3432NK cells.7∼87∼1.51982.11721.6212    CD56 dim.65∼79∼1.41922.21681.6202B cells2.81471.8104.97*68*1.9160    Pro B.11—.06—.02*—.07—    Pre B.6—.4—.08—.23—    Naive SP—80—57^—36*—118    Normal-PCS.18.9.11.7.008.72*.11.84DCs.3449.3653.6848.558    Monocytes2.22472.42853.43023.1315    m-DC SP—11—14—8*—12    MO-DC.11∼29.2036.434.2837    p-DC.2∼4.1.145.112.8.123.8CD34+.9∼1.46.61.1.261.4.431.4    Mie-HPC.8∼—.53—.26—.36—    Linfo-HPC.1—.07—.03*—.05—*p≤.05 LTDC vs MM: ^ p≤.05 LTDC vs MGUS; ∼ p≤.05 LTDC vs HA Disclosures: Paiva: Jansen-Cillag: Honoraria; Celgene: Honoraria. Martinez:Janssen: Honoraria; Celgene: Honoraria. Maiolino:Centocor Ortho Biotech Research & Development: Research Funding.

Description: The development of novel targeted therapies in Multiple Myeloma (MM) has opened promising expectations for the treatment of this incurable hematological malignancy. However, the molecular mechanisms of both novel biologically based therapies and conventional treatments are still unclear. The purpose of the present study was to evaluate the changes in the gene expression profile of the human multiple myeloma cell line (MM.1S) following exposure to Doxorubicin, Melphalan, Bortezomib, Aplidin and Arsenic Trioxide. We have focused on the analysis of the early steps of activation of molecular mechanisms that lead to MM cell death. For this purpose we investigated with a time-course the onset of the apoptosis for every drug, according to the flow cytometric analysis with Annexin V- FITC Apoptosis Detection Reagent Kit. Based on these results the optimal concentration and time of exposure for each of the drugs were as follows Melphalan 50 μM, 9hours; Doxorubicin 1 μM, 17hours; Bortezomib 10 nM, 6 hours; Aplidin 50 nM, 4 hours and Arsenic Trioxide 5 mM, 3 hours. Affymetrix HG-U133A array containing around 15,000 full-length genes was used for mRNA expression profiling. All the experiments were performed in duplicate. The DNA- Chip Analyzer (DChip) was used to normalize and compare samples. Genes with expression changes greater than twofold in either direction were considered significant. A total of 269, 74, 74, 808 and 525 genes showed a significantly altered expression pattern, in response to Melphalan, Doxorubicin, Bortezomib, Aplidin and Arsenic Trioxide, respectively. Our results demonstrate that treatment with Melphalan inhibits DNA replication and transcription (underexpression of POLA, RFC1) as well as proliferation and survival (underexpression of IGF-1); it blocks the cell cycle (overexpression of CDKN1A and PA26) and induces apoptosis (overexpression of GADD45B). Doxorubicin deregulates many genes involved in cell cycle arrest (high expression of CDKN1A, PA26, GADD45A and low expression of CCND2 y CDC20) as well as up-regulation of several members of the TNF family (CD95, TRAILR2 and CD27). Bortezomib increases the expression of many “heat shock proteins” (HSP 110, HSP 70B, HSP 70B′) and decreases the level expression of IGF-1. Aplidin triggers early induction of many genes involved in apoptosis (overexpression of MAP4K3 and EGR2) and down-regulation of genes that play and important role in G2/M phase transition (NEK2, CENPF, BUB1). Arsenic Trioxide induces underexpression of essential genes for G1/S phase transition and cell cycle progression (CDC7L1, CDC25A) as well as underexpression of genes that mediate spindle formation and cromosome segregation (STK6, PRC1, HCAP-G, ZWINT, KIF4A, BUB1). Moreover, Arsenic Trioxide alike Bortezomib treatment up-regulates several HSP (HSP 40, HSP70B, HSP27). TNFSF9 which inhibits proliferation was the only gene up-regulated by all the drugs. Microarray technology demonstrates that treatment with novel targeted therapies (Bortezomib, Aplidin and Arsenic Trioxide) induces deregulation of molecular mechanisms which are not involved in anti-myeloma activity of conventional treatments (Melphalan, Doxorubicin). In addition it is an efficient tool to understand the differences in mechanisms of action of novel drugs.

Description: MicroRNAs (miRNAs) are small non-coding RNA that regulate gene expression by inducing RNA degradation or translational inhibition of their mRNA targets. Recently, deregulation of miRNAs has been associated with cancer development. MiRNA expression profiling has been analysed in different hematological malignancies, but the information about miRNA expression in MM is limited. We investigated the expression levels of 368 miRNAs using a quantitative PCR-method (“TaqMan low density arrays-microRNA assay”, Applied Biosystems) in 49 patients with newly diagnosed MM. Moreover, 4 MM cell lines (MM1S, OPM2, U266 and RPMI) and 4 samples of normal human plasma cells (PC) were also included in the study. In all the bone marrow samples a CD138 positive PC isolation was performed. Relative quantification of miRNA expression was calculated with the 2−ΔΔCt method. The data were normalized respect to RNU48 and relative to a calibrator sample (average of normal human PC samples). Hierarchical clustering based on the average-linkage method with the centered correlation metric was used for unsupervised analysis. Differentially expressed miRNAs were identified using “Significant Analysis of Microarrays” (SAM) algorithm, the t test and the nonparametric Wilcoxon rank sum test. Primary myeloma cells displayed a distinctive miRNA expression pattern compared to normal PC, characterized by the downregulation of the miRNAs differentially expressed. Unsupervised analysis of the data revealed that the MM samples segregated mainly into two clusters: one contained 12 out the 14 MM cases with t(4;14), 20 out of the 30 MM cases with RB deletion, and the 3 samples with t(14;16) which were tightly clustered. The other cluster contained 5 out of the 7 MM samples without genetic abnormalities (IGH translocation, RB and P53 deletions and gain on 1q were ruled out by FISH analysis). MM samples with t(11;14) and those with gains on 1q were dispersed along the dendrogram. The comparative analysis of the miRNA expression profile between MM with t(4;14) and the remaining MM samples showed a set of 5 up-regulated miRNA (let-7c, miR-125a, miR-125b, miR-135a, miR-99a) in the t(4;14) group. Although MM samples with t(11;14) were not clustered together, the supervised analysis identified two upregulated miRNAs (miRNA-345 and miRNA-193a) compared to those MM cases without this translocation. None of the differentially expressed miRNA was located in the chromosomal regions involved in the specific translocations. Upon comparing the miRNA expression in cases with or withouth RB deletion it was found that the three most differentially expressed miRNA were miR-145, miRNA-378 and let-7b (downregulated in MM with RB deletion). There was no correlation between the expression level of miRNAs located on chromosome 13 and the RB status by FISH. In the same way, the miRNAs differentially expressed in MM with 1q gains were not located in 1q. In summary, these results indicate that miRNA expression is deregulated in myeloma cells, and what is more important, the miRNA pattern of expression in MM seems to be associated with specific genetic abnormalities, which indicate that they may play a relevant role in MM pathogenesis.