Prognostic factors in 448 newly diagnosed multiple myeloma receiving bortezomib-based induction: impact of ASCT, transplant refusal and high-risk MM.

In Hong Kong, newly diagnosed multiple myeloma (NDMM) receives bortezomib-based triplet induction. Upfront autologous stem cell transplant (ASCT) is offered to transplant eligible (TE) patients (NDMM ≤ 65 years of age), unless medically unfit (TE-unfit) or refused (TE-refused). Data was retrieved for 448 patients to assess outcomes. For the entire cohort, multivariate analysis showed that male gender (p = 0.006), international staging system (ISS) 3 (p = 0.003), high lactate dehydrogenase (LDH) (p = 7.6 × 10-7) were adverse predictors for overall survival (OS), while complete response/ near complete response (CR/nCR) post-induction (p = 2.7 × 10-5) and ASCT (p = 4.8 × 10-4) were favorable factors for OS. In TE group, upfront ASCT was conducted in 252 (76.1%). Failure to undergo ASCT in TE patients rendered an inferior OS (TE-unfit p = 1.06 × 10-8, TE-refused p = 0.002) and event free survival (EFS) (TE-unfit p = 0.00013, TE-refused p = 0.002). Among TE patients with ASCT, multivariate analysis showed that age ≥ 60 (p = 8.9 × 10-4), ISS 3 (p = 0.019) and high LDH (p = 2.6 × 10-4) were adverse factors for OS. In those with high-risk features (HR cytogenetics, ISS 3, R-ISS 3), ASCT appeared to mitigate their adverse impact. Our data reaffirmed the importance of ASCT. The poor survival inherent with refusal of ASCT should be recognized by clinicians. Finally, improved outcome with ASCT in those with high-risk features warrant further studies.

Bortezomib, Melphalan, and Prednisone With or Without Daratumumab in Transplant-ineligible Asian Patients With Newly Diagnosed Multiple Myeloma: The Phase 3 OCTANS Study.

INTRODUCTION: In the global phase 3 ALCYONE trial, daratumumab plus bortezomib/melphalan/prednisone (D-VMP) improved outcomes versus VMP in transplant-ineligible newly diagnosed multiple myeloma (NDMM) patients. Here, we report the primary analysis of the phase 3 OCTANS trial of D-VMP versus VMP in transplant-ineligible Asian NDMM patients. PATIENTS AND METHODS: In total, 220 patients were randomized (2:1) to receive 9 cycles of VMP (bortezomib 1.3 mg/m2 subcutaneously twice weekly in Cycle 1 and weekly in Cycles 2 to 9; melphalan 9 mg/m2 orally; and prednisone 60 mg/m2 orally on Days 1 to 4 of each cycle) ± daratumumab 16 mg/kg intravenously weekly in Cycle 1, every 3 weeks in Cycles 2 to 9, and every 4 weeks thereafter until disease progression. RESULTS: After a median follow-up of 12.3 months, very good partial response or better rates (primary endpoint) were 74.0% versus 43.2% with D-VMP versus VMP (odds ratio, 3.57; 95% confidence interval [CI], 1.99-6.43; P < .0001). Median progression-free survival (PFS) with D-VMP versus VMP was not reached versus 18.2 months (hazard ratio, .43; 95% CI, .24-.77; P = .0033); 12-month PFS rates were 84.2% versus 64.6%. The most frequent grade 3/4 treatment-emergent adverse events with D-VMP/VMP were thrombocytopenia (46.5%/45.1%), neutropenia (39.6%/50.7%), and leukopenia (31.3%/36.6%). CONCLUSION: D-VMP demonstrated a favorable benefit/risk profile in transplant-ineligible Asian NDMM patients. This trial was registered at www. CLINICALTRIALS: gov as #NCT03217812.

The impact of bortezomib-based induction in newly diagnosed multiple myeloma with chromosome 1q21 gain.

Introduction: Bortezomib has been reported to favourably impact the outcomes of t(4;14) and del(17p) in multiple myeloma (MM), but its impact on gain 1q (+1q) is unknown. Methods: To address this, 250 patients treated with bortezomib-based induction were analysed. All myeloma samples had fluorescence in situ hybridization (FISH) performed on CD138-sorted bone marrow aspirate, and plasma cells were analysed using DNA probes specific for the following chromosomal aberrations: del(13q14), del(17p), t(14;16), t(4;14), and +1q. Presence of +1q was defined as the presence of at least three copies of 1q21 at the cut off level of 20% of bone marrow plasma cells. Results: +1q identified in 167 (66.8%) and associated with t(4;14) and high lactate dehydrogenase (LDH). +1q was not associated with response rate but shorter event-free survival (EFS) (median EFS 35 vs 55 months, p = 0.05) and overall survival (OS) (median OS 74 vs 168 months, p = 0.00025). Copy number and clone size did not impact survival. Multivariate analysis showed +1q was an independent adverse factor for OS together with International Staging System (ISS)3, high LDH, del(17p) and t(4;14). When a risk score of 1 was assigned to each independent adverse factor, OS was shortened incrementally by a risk score from 0 to 4. Post-relapse/progression survival was inferior in those with +1q (median 60 vs 118 months, p = 0.000316). Autologous stem cell transplantation (ASCT) improved OS for those with +1q (median OS 96 vs 49 months, p = 0.000069). Conclusion: +1q is an adverse factor for OS in MM uniformly treated with bortezomib-based induction but was partially mitigated by ASCT. A risk scoring system comprising +1q, LDH, high-risk FISH, and ISS is a potential tool for risk stratification in MM.

Epigenetic Silencing of Tumor Suppressor lncRNA NKILA: Implication on NF-κB Signaling in Non-Hodgkin's Lymphoma.

The long non-coding RNA (lncRNA) NKILA, localized to 20q13.31, is a negative regulator of NF-κB signaling implicated in carcinogenesis. As a CpG island is embedded in the promoter region of NKILA, it is hypothesized as a tumor suppressor lncRNA silenced by promoter DNA methylation in non-Hodgkin's lymphoma (NHL). By pyrosequencing-verified methylation-specific PCR, NKILA methylation was detected in 1/10 (10%) NHL cell lines, but not in normal peripheral blood buffy coats or tonsils. NKILA methylation correlated with the repression of NKILA in cell lines. Hypomethylation treatment with 5-Aza-2'-deoxycytidine resulted in promoter demethylation and the re-expression of NKILA. In 102 NHL primary samples, NKILA was methylated in 29 (51.79%) diffuse large B-cell lymphoma (DLBCL) and 4 (20%) peripheral T-cell lymphoma cases, but unmethylated in all 26 mantle cell lymphoma cases. Mechanistically, the knockdown of NKILA resulted in promoting IkBα phosphorylation, associated with nucleus translocation of total p65 and phosphorylated p65 in SU-DHL-1 cells, hence constitutive NF-κB activation. Functionally, the knockdown of NKILA in SU-DHL-1 cells led to decreased cell death and increased cellular proliferation. Collectively, NKILA was a tumor suppressor lncRNA frequently hypermethylated in DLBCL. Promoter DNA methylation-mediated NKILA silencing resulted in increased cellular proliferation and decreased cell death via the repression of NF-κB signaling in NHL.

Case series: MRD negativity assessment using 11C-Acetate PET with 3-weekly daratumumab-based quadruplet induction in newly diagnosed multiple myeloma.

Complete response (CR) is an important favorable factor for survival in multiple myeloma (MM). However, CR patients continue to relapse, especially in the presence of minimal residual disease (MRD). Bone marrow (BM) MRD is predictive of progression-free survival (PFS) in MM. However, myeloma outside the BM aspiration site may result in subsequent relapse despite MRD-negativity. Therefore, positron emission tomography-computed tomography (PET-CT) based on F-fluorodeoxyglucose (FDG) is a complementary tool to monitor residual disease in MM. However, FDG may miss myeloma lesions that are not FDG-avid. On the other hand, 11C-Acetate (ACT) has been found to be a more sensitive and specific tracer than FDG in MM. Recently, the addition of daratumumab to bortezomib, thalidomide, dexamethasone (VTd) or bortezomib, lenalidomide, dexamethasone (VRd) backbone has been proven to improve outcomes. Herein, we report three newly-diagnosed MM patients achieving deep responses with imaging CR using ACT PET in addition to conventional immunofixation CR and MRD-negative CR after a 3-weekly daratumumab-based quadruplet induction regimen.

3-weekly daratumumab-lenalidomide/pomalidomide-dexamethasone is highly effective in relapsed and refractory multiple myeloma.

OBJECTIVES: Myeloma relapse remains challenging. Daratumumab (dara) with immunomodulatory agents (IMiD) and dexamethasone (dex) was proven highly effective in relapsed or refractory multiple myeloma (RRMM) in randomized controlled trials. The recommended schedule of dara is weekly for eight doses, followed by 2-weekly for eight doses, and then every 4-weekly thereafter. However, the cost of daratumumab is daunting, precluding widespread and prolonged use in some countries. In this study, we aimed to evaluate the efficacy of using a 3-weekly daratumumab regimen in RRMM. METHODS: Thirteen RRMM patients were treated with dara-IMiD-dex till maximal response, followed by single-agent IMiD maintenance until disease progression. Dara (every 6 weekly) would be added upon significant biochemical disease progression. RESULTS: After a median of four daratumumab infusions (range: 3-10), the best responses included complete response (CR) in seven patients (53.8%), very good partial response (VGPR) in four patients (30.8%), and partial response (PR) in two patients (15.4%). The median time to VGPR was four weeks. At 10 months, the overall survival was 90%, and progression-free survival was 54.7%. Two of three patients tested achieved MRD-ve CR. Another patient, who had PET-CT reassessment, showed PET-ve CR. DISCUSSION: Despite less frequent daratumumab use, we reported rapid responses with a median time to VGPR of only four weeks, and a response rate of 100% including CR rate of 54%. Despite less frequent daratumumab use, grade ¾ neutropenia remained common with a frequency comparable to that observed in Pollux. CONCLUSION: This 3-weekly dara-IMiD-dex regimen preserves a high efficacy with rapid, deep responses including MRD-ve and PET-ve CR, hence a cost-effective regimen.

miR-1250-5p is a novel tumor suppressive intronic miRNA hypermethylated in non-Hodgkin's lymphoma: novel targets with impact on ERK signaling and cell migration.

BACKGROUND: miR-1250 is localised to the second intron of AATK at chromosome 17q25. As a CpG island is present at the putative promoter region of its host gene, AATK, we postulated that the intronic miR-1250-5p is a tumor suppressor miRNA co-regulated with its host gene, AATK, by promoter DNA methylation in non-Hodgkin's lymphoma (NHL). METHODS: AATK/miR-1250 methylation was studied in healthy controls, including ten normal peripheral blood buffy coats and eleven normal tonsils, ten lymphoma cell lines, and 120 primary lymphoma samples by methylation-specific PCR (MSP). The expression of miR-1250-5p and AATK was investigated by quantitative real-time PCR. Tumor suppressor properties of miR-1250-5p were demonstrated by over-expression of precursor miR-1250-5p in lymphoma cells. The target of miR-1250-5p was verified by luciferase reporter assay. RESULTS: AATK/miR-1250 methylation was absent in healthy peripheral blood and tonsils, but detected in five (50%) NHL cell lines. AATK/miR-1250 methylation correlated with repression of miR-1250-5p and AATK in NHL cell lines. In completely methylated SU-DHL-6 and SUP-T1 cells, treatment with 5-AzadC led to promoter demethylation and re-expression of both miR-1250-5p and AATK. In primary lymphoma samples, AATK/miR-1250 was frequently methylated in B-cell lymphoma (n = 41, 44.09%) and T-cell lymphoma (n = 9, 33.33%) with a comparable frequency (P = 0.318). In SU-DHL-6 and SU-DHL-1 cells, restoration of miR-1250-5p resulted in decreased cellular proliferation by MTS assay, increased cell death by trypan blue staining and enhanced apoptosis by annexin V-PI assay. Moreover, MAPK1 and WDR1 were verified as direct targets of miR-1250-5p by luciferase assay. In 39 primary NHLs, miR-1250-5p expression was shown to be inversely correlated with each of MAPK1 (P = 0.05) and WDR1 (P = 0.031) by qRT-PCR. Finally, in SU-DHL-1 cells, overexpression of miR-1250-5p led to repression of MAPK1 and WDR1 at both transcript and protein levels, with downregulation of phospho-ERK2 by Western-blotting and inhibition of SDF-1-dependent cell migration by transwell assay. CONCLUSIONS: miR-1250-5p is a novel tumor suppressive intronic miRNA co-regulated and silenced by promoter DNA methylation of its host gene AATK in NHL. MAPK1 and WDR1 are novel miR-1250-5p direct targets rendering inhibition of MAPK/ERK signaling and SDF-1-dependent cell migration, hence implicated in survival and dissemination of lymphoma. Video Abstract.

A proof-of-concept study for the pathogenetic role of enhancer hypomethylation of MYBPHL in multiple myeloma.

Enhancer DNA methylation and expression of MYBPHL was studied in multiple myeloma (MM). By bisulfite genomic sequencing, among the three CpGs inside the MYBPHL enhancer, CpG1 was significantly hypomethylated in MM cell lines (6.7-50.0%) than normal plasma cells (37.5-75.0%) (P = 0.007), which was negatively correlated with qPCR-measured MYBPHL expression. In RPMI-8226 and WL-2 cells, bearing the highest CpG1 methylation, 5-azadC caused enhancer demethylation and expression of MYBPHL. In primary samples, higher CpG1 methylation was associated with lower MYBPHL expression. By luciferase assay, luciferase activity was enhanced by MYBPHL enhancer compared with empty vector control, but reduced by site-directed mutagenesis of each CpG. RNA-seq data of newly diagnosed MM patients showed that MYBPHL expression was associated with t(11;14). MOLP-8 cells carrying t(11;14) express the highest levels of MYBPHL, and its knockdown reduced cellular proliferation and increased cell death. Herein, as a proof-of-concept, our data demonstrated that the MYBPHL enhancer, particularly CpG1, was hypomethylated and associated with increased MYBPHL expression in MM, which was implicated in myelomagenesis.

Epigenetic silencing of miR-342-3p in B cell lymphoma and its impact on autophagy.

BACKGROUND: miR-342-3p, localized to 14q32, is a tumor suppressor miRNA implicated in carcinogenesis. Given the presence of a promotor-associated CpG island for its host gene, EVL, we hypothesized that intronic miR-342-3p is a tumor suppressor co-regulated with host gene by promoter DNA methylation in B cell lymphoma. RESULTS: By bisulfite pyrosequencing-verified methylation-specific PCR (MSP), EVL/MIR342 methylation was detected in five (50%) lymphoma cell lines but not normal peripheral blood and tonsils. EVL/MIR342 methylation correlated with repression of both miR-342-3p and EVL in cell lines. In completely methylated SU-DHL-16 cells, 5-AzadC treatment resulted in promoter demethylation and re-expression of miR-342-3p and EVL. In 132 primary lymphoma samples, EVL/MIR342 was preferentially methylated in B cell lymphomas (N = 68; 68.7%) than T cell lymphoma (N = 8; 24.2%) by MSP (P < 0.0001). Moreover, EVL/MIR342 methylation was associated with lower miR-342-3p expression in 79 primary NHL (P = 0.0443). In SU-DHL-16 cells, the tumor suppressor function of miR-342-3p was demonstrated by the inhibition of cellular proliferation and increase of cell death upon over-expression of miR-342-3p. Mechanistically, overexpression of miR-342-3p resulted in a decrease of LC3-II, a biomarker of autophagy, which was pro-survival for SU-DHL-16. Pre-treatment with 3-methyladenine, an autophagy inhibitor, abrogated tumor suppression associated with miR-342-3p overexpression. By luciferase assay, MAP1LC3B, a precursor of LC3-II, was confirmed as a direct target of miR-342-3p. Finally, in SU-DHL-16 cells, overexpression of miR-342-3p downregulated the known target DNMT1, with promoter demethylation and re-expression of tumor suppressor E-cadherin. CONCLUSIONS: Intronic miR-342-3p is co-regulated with its host gene EVL by tumor-specific promoter DNA methylation in B cell lymphoma. The tumor suppressor function of miR-342-3p was mediated via inhibition of pro-survival autophagy by targeting MAP1LC3B and downregulation of DNMT1 with demethylation and re-expression of tumor suppressor genes.

Epigenetic silencing of long non-coding RNA BM742401 in multiple myeloma: impact on prognosis and myeloma dissemination.

BACKGROUND: Long non-coding RNA (lncRNA) BM742401 is a tumor suppressor in gastric cancer and chronic lymphocytic leukemia. As the promoter and coding region of BM742401 are fully embedded in a CpG island, we hypothesized that BM742401 is a tumor suppressor lncRNA epigenetically silenced by promoter DNA methylation in multiple myeloma. METHODS: Methylation-specific PCR and quantitative bisulfite pyrosequencing were performed to detect the methylation of BM742401 in normal plasma cells, myeloma cell lines and primary myeloma samples. The expression of BM742401 was measured by qRT-PCR. The function of BM742401 in multiple myeloma cells was analyzed by lentivirus transduction followed by migration assay. RESULTS: BM742401 methylation was detected in 10 (66.7%) myeloma cell lines but not normal plasma cells, and inversely correlated with expression of BM742401. In primary samples, BM742401 methylation was detected in 3 (12.5%) monoclonal gammopathy of undetermined significance, 9 (15.8%) myeloma at diagnosis and 8 (17.0%) myeloma at relapse/progression. Moreover, BM742401 methylation at diagnosis was associated with inferior overall survival (median OS: 25 vs. 39 months; P = 0.0496). In myeloma cell line JJN-3, stable overexpression of BM742401 by lentivirus transduction resulted in reduced cell migration (P = 0.0001) but not impacting cell death or proliferation. CONCLUSIONS: This is the first report of tumor-specific methylation-mediated silencing of BM742401 in myeloma, which is likely an early event in myelomagenesis with adverse impact on overall survival. Moreover, BM742401 is a tumor suppressor lncRNA by inhibiting myeloma cell migration, hence implicated in myeloma plasma cell homing, metastasis and disease progression.

Low-dose pembrolizumab and nivolumab were efficacious and safe in relapsed and refractory classical Hodgkin lymphoma: Experience in a resource-constrained setting.

The efficacy and safety of low-dose anti-PD1 antibodies in relapsed/refractory classical Hodgkin lymphoma (cHL) require confirmation. Pembrolizumab (100 mg every 3 weeks, Q3W) or nivolumab (40 mg Q2W) were administered to patients with relapsed/refractory cHL. In the pembrolizumab cohort (N = 11), who had failed a median of three (1-6) therapies (brentuximab vedotin [BV]: 91%; autologous hematopoietic stem cell transplantation [auto-HSCT]: 18%), the overall response rate (ORR) by positron emission tomography-computed tomography was 100% (metabolic complete response [mCR]: 73%; partial response [PR]: 27%). Median cumulative dose for achieving best response was 400 (300-800) mg. Median progression-free survival (PFS) was 35 months. Median overall survival (OS) was not reached. Adverse events (AEs) of grade 1-2 were observed in three patients. In the nivolumab cohort (N = 6), who had failed a median of three (2-6) therapies (BV: 50%; auto-HSCT: 17%; allogeneic HSCT: 34%), the ORR was 100% (mCR: 67%; PR: 17%; indeterminate response: 17%). Median cumulative dose for achieving best response was 160 (160-360) mg. Median PFS was 33 months. Median OS was not reached. AEs of grade 1-2 were observed in four patients, two of whom had pre-existing autoimmune conditions. Five patients with Epstein-Barr virus (EBV) positive Reed-Sternberg cells underwent monitoring of plasma EBV DNA, which became negative in four mCR patients but remained positive in one PR patient who died ultimately from refractory lymphoma. Low-dose pembrolizumab and nivolumab were highly efficacious and safe in relapsed/refractory cHL. These observations have significant financial implications in resource-constrained settings.

Primary refractory multiple myeloma: a real-world experience with 85 cases.

This study determined whether 85 patients with multiple myeloma (MM) double-refractory to primary induction therapy with triplet regimens had a homogenous prognosis. The overall response rate (ORR) after the second-line therapy was 51%. Patients who proceeded to immediate autologous stem cell transplantation (ASCT) had better ORR than those who received conventional therapies (62% vs. 31%). The ORR for patients who had ASCT directly after the frontline therapy was higher than for those treated with other regimens as the second line therapy (91% vs. 45%) and offered ASCT as the third-line therapy (91% vs. 55%). The median progression-free survival (PFS) after the second-line therapy and median overall survival were 21.6 months and 35.6 months, respectively. ASCT after the second line treatment (HR = 0.24) was an independent predictor of PFS. Eligible patients with primary refractory MM achieve the most benefit from ASCT, also performed immediately after first line induction therapy.

Venetoclax, bortezomib and S63845, an MCL1 inhibitor, in multiple myeloma.

OBJECTIVES: Venetoclax, an orally available BCL2-selective inhibitor, has demonstrated promising single-agent anti-tumour activity in myeloma especially patients with t(11;14). Herein, whether venetoclax sensitivity could be enhanced or restored in combination with bortezomib or S63845, a novel MCL1-selective inhibitor, was examined in human myeloma cell lines (HMCLs), including bortezomib-resistant HMCLs. METHODS: By MTS assay, half-maximal inhibitory concentration (IC50 ) and hence sensitivity/resistance to venetoclax, bortezomib and S63845 were determined. KEY FINDINGS: Venetoclax (IC50 ≥100 nm), bortezomib (IC50 ≥50 nm) and S63845 (IC50 ≥100 nm) resistance was observed in nine (75%), three (25%) and six (50%) HMCLs, respectively. Moreover, venetoclax sensitivity was independent of bortezomib (R2  = 0.1107) or S63845 (R2  = 0.0213) sensitivity. Venetoclax sensitivity correlated with high mRNA ratio of BCL2/MCL1 (P = 0.0091), BCL2/BCL2L1 (P = 0.0182) and low MCL1 expression (P = 0.0091). In HMCLs sensitive to both venetoclax and bortezomib/S63845, venetoclax combined with S63845 showed stronger synergistic effect than combined with bortezomib. Moreover, in venetoclax-resistant HMCLs, S63845, but not bortezomib, significantly restored venetoclax sensitivity. Conversely, bortezomib combined with S63845 did not result in augmented bortezomib sensitivity or abolishment of bortezomib resistance. CONCLUSIONS: Regardless of t(11;14), combination of venetoclax with S63845 is a promising strategy in enhancing venetoclax sensitivity or overcoming venetoclax resistance in myeloma therapy, hence warrant future clinical studies.

Minimal Residual Disease Detection by Next-Generation Sequencing in Multiple Myeloma: A Comparison With Real-Time Quantitative PCR.

Here we compared clonotype identification by allele-specific oligonucleotide real-time quantitative-PCR (ASO RQ-PCR) and next-generation sequencing (NGS) in 80 multiple myeloma patients. ASO RQ-PCR was applicable in 49/55 (89%) and NGS in 62/78 (80%). Clonotypes identified by both methods were identical in 33/35 (94%). Sensitivity of 10-5 was confirmed in 28/29 (96%) by NGS while sensitivity of RQ-PCR was 10-5 in 7 (24%), 5 × 10-5 in 15 (52%), and 10-4 in 7 (24%). Among 14 samples quantifiable by ASO RQ-PCR, NGS yielded comparable results in 12 (86%). Applicability of NGS can be improved if immunoglobulin heavy-chain incomplete DJ primers are included.

Pomalidomide and dexamethasone combination with additional cyclophosphamide in relapsed/refractory multiple myeloma (AMN001)-a trial by the Asian Myeloma Network.

Pomalidomide is a third generation immunomodulatory drug which in combination with dexamethasone, has been shown to be active in relapsed/refractory multiple myeloma. However, the data in Asian patients remain limited. We conducted a prospective phase two clinical trial in major cancer centers in Singapore, South Korea, Taiwan, Japan and Hong Kong to assess the efficacy and safety of pomalidomide and dexamethasone combination (PomDex) +/- cyclophosphamide in Asian patients with relapsed/refractory multiple myeloma who failed lenalidomide and bortezomib. Patients were treated with pomalidomide (4 mg daily for 21 days every 4 weeks) and dexamethasone (40 mg weekly). If there is less than a minimal response after three cycles of PomDex, cyclophosphamide 300 mg/m2 can be added (PomCyDex). A total of 136 patients were enrolled. The median PFS was 9 and 10.8 months for the PomDex and PomCyDex group, respectively. The median OS was 16.3 months. This regimen appears to be active across age groups and prior lines of treatment. This combination was overall well tolerated with grade 3 and 4 adverse events of mainly cytopenias. PomDex is highly active and well-tolerated in Asian patients. The addition of cyclophosphamide can improve the response and outcomes further in patients with suboptimal response to PomDex.

Ficolled bone marrow is superior to bone marrow buffy coat for detection of minimal residual disease in multiple myeloma.

OBJECTIVE: Buffy coat and ficoll of bone marrow (BM) are viable options for the study of minimal residual disease (MRD) in multiple myeloma (MM). As yet, there is no data about the superiority of either sample types. Herein, we aimed to address this issue. METHODS: Forty pairs of ficolled BMs and BM buffy coats of 19 MM patients were studied for MRD by allele-specific oligonucleotide real-time quantitative PCR, with patient-specific primers/probes whenever appropriate. RESULTS: There were 41 pairs of MRD data for comparison analysis due to one patient with biclonal disease. MRD levels in ficolls and buffy coats were highly concordant (rs = 0.936, P < 0.0001), with 31 (76%) and seven (17%) pairs being concomitantly MRD-positive or -negative. On the other hand, apart from the 16 pairs being both MRD-negative, or -positive but not quantifiable in ficolls and buffy coats, majority (n = 22, 88%) had higher MRD levels in ficolled BMs than BM buffy coats. Furthermore, in 17 pairs, in which MRD was quantifiable in both, MRD levels in ficolled BMs were 3.1 times those of BM buffy coats (median, 567/105 vs. 184/105, P = 0.001). CONCLUSION: Taken together, ficolled BM is more sensitive than BM buffy coat for MRD detection in MM, hence should be recommended.

Standardized Minimal Residual Disease Detection by Next-Generation Sequencing in Multiple Myeloma.

Next-generation sequencing (NGS) has been applied to monitor minimal residual disease (MRD) in multiple myeloma (MM). Standardized DNA input and sequencing depth is essential for achieving a uniform sensitivity in NGS-based MRD study. Herein, the sensitivity of 10-5 was verified by a standardized experimental design based on triplicate measurements of 1 µg DNA input and 1 million sequencing reads using the LymphoTrack-MiSeq platform. MRD level was defined as the mean MRD burden of the triplicates. Two spike-in controls at concentrations of 0.001% tumor plasma cells (PC) for verifying the sensitivity of 10-5 and 0.01% (or 0.005%) for MRD normalization were systematically analyzed. The spike-in control of 0.001% MRD was consistently detected in all samples, confirming a sensitivity of 10-5. Moreover, this standardized NGS approach yielded MRD measurements concordant with serological response and comparable to allele-specific oligonucleotide (ASO) real-time quantitative (RQ)-PCR. Moreover, NGS showed an improved sensitivity and provided quantification of MRD for cases assigned "positive but not quantifiable" (PNQ) by ASO RQ-PCR, even without the use of patient-specific probes/primers. Issues regarding the specificity of myeloma-specific sequences as MRD target, optimal input for spike-in normalization, and interpretation of MRD from triplicates are discussed. Herein, the standardized LymphoTrack-MiSeq-based method is verified to carry a sensitivity of 10-5, hence an effective tool for MRD monitoring in MM. As only a small number of samples are tested here, further study with a larger number of patients is warranted.

Epigenetic silencing of miR-340-5p in multiple myeloma: mechanisms and prognostic impact.

BACKGROUND: miR-340-5p, localized to 5q35, is a tumor suppressor miRNA implicated in multiple cancers. As a CpG island is present at the putative promoter region of its host gene, RNF130, we hypothesized that the intronic miR-340-5p is a tumor suppressor miRNA epigenetically silenced by promoter DNA methylation of its host gene in multiple myeloma. RESULTS: By pyrosequencing-confirmed methylation-specific PCR, RNF130/miR-340 was methylated in 8/15 (53.3%) myeloma cell lines but not normal plasma cells. Methylation correlated inversely with the expression of both miR-340-5p and RNF130. In completely methylated WL-2 and RPMI-8226R cells, 5-AzadC treatment led to demethylation and re-expression of miR-340-5p. In primary samples, RNF130/miR-340 methylation was detected in 4 (22.2%) monoclonal gammopathy of undetermined significance, 15 (23.8%) diagnostic myeloma, and 7 (23.3%) relapsed myeloma. RNF130/miR-340 methylation at diagnosis was associated with inferior overall survival (median 27 vs. 68 months; P = 3.944E-5). In WL-2 cells, overexpression of miR-340-5p resulted in reduced cellular proliferation [MTS, P = 0.002; verified in KMS-12-PE (P = 0.002) and RPMI-8226R (P = 2.623E-05) cells], increased cell death (trypan blue, P = 0.005), and enhanced apoptosis by annexin V-PI staining. Moreover, by qRT-PCR, overexpression of miR-340-5p led to repression of both known targets (CCND1 and NRAS) and bioinformatically predicted targets in MAPK signaling (MEKK1, MEKK2, and MEKKK3) and apoptosis (MDM4 and XIAP), hence downregulation of phospho-ERK1/2 and XIAP by Western blot. Furthermore, by qRT-PCR, in CD138-sorted primary samples (n = 37), miR-340-5p and XIAP were inversely correlated (P = 0.002). By luciferase assay, XIAP was confirmed as a direct target of miR-340-5p via targeting of the distal but not proximal seed region binding site. CONCLUSIONS: Collectively, tumor-specific methylation-mediated silencing of miR-340-5p is likely an early event in myelomagenesis with adverse survival impact, via targeting multiple oncogenes in MAPK signaling and apoptosis, thereby a tumor suppressive miRNA in myeloma.

Survival differences in multiple myeloma in Latin America and Asia: a comparison involving 3664 patients from regional registries.

In previous observational studies, we have separately characterized patients with multiple myeloma (MM) both from Latin America (LA) and from Asia. Here, we analyze these two datasets jointly, in order to assess the overall survival (OS) in these two world regions. Data were available from 3664 patients (1968 from LA and 1696 from Asia); all of whom diagnosed between 1998 and 2007. Approximately, 26% of patients in both world regions underwent transplantation. OS (from diagnosis of MM) was explored with Kaplan-Meier analyses and Cox proportional hazards models. Patients from LA were significantly younger and had hypercalcemia more often than Asian patients, who in turn had higher proportions of anemia and International Staging System (ISS) stage III disease. The median OS was 56 months in LA, and 47 months in Asia (hazard ratio [HR] = 0.83; 95% confidence interval [CI], 0.76 to 0.91; P < 0.001). In multivariable analysis, age, ISS stage III, anemia, hypercalcemia, and world region remained significantly associated with OS (P < 0.001 for all covariates). These results were largely driven by patients not undergoing transplantation, as no difference in OS emerged between the two world regions in univariable or multivariable analysis for transplanted patients. Despite adverse prognostic features differentially favoring each region, and adjusting for such differences, we found an OS advantage for patients from LA, in comparison with contemporaneous patients from Asia. Whether this is due to different biological features, differences in access to novel agents (especially thalidomide in earlier periods of the study), unmeasured confounders, or the play of chance, remain unknown.