Weiwei Sui

Chromosome 1q21 gains confer inferior outcomes in multiple myeloma treated with bortezomib but copy number variation and percentage of plasma cells involved have no additional prognostic value

Chromosome 1q21 aberrations have not been yet been made part of routine clinical tests and their effect in multiple myeloma is still under investigation. The prognostic value of copy number variation and percentage of plasma cells involved have remained unclear. In the present study, we analyzed the prognostic value of 1q21 in a series of 290 cases of newly diagnosed multiple myeloma treated in a prospective, non-randomized clinical trial (BDH 2008/02). We found that incidence of 1q21 aberration increased at relapse, but its copy numbers and proportion of cells involved did not change. Gains of 1q21 had no impact on survival in patients receiving thalidomide-based treatment but conferred a significantly inferior prognosis in patients under bortezomib-based chemotherapy and was an independent adverse prognostic factor for progression free survival (HR 3.831; 95%CI: 2.125–6.907; P<0.001) and overall survival (HR 3.245; 95%CI: 1.555–6.773; P=0.002). Strikingly, our results showed that the copy number variation and clone size harboring 1q21 gains carried no additional prognostic value and patients with 1q21 gains did not benefit significantly from regimens incorporating bortezomib. Our results indicate that three copies of 1q21 and 20% of plasma cells with this abnormality were enough to confer bortezomib resistance. Therefore, chromosome 1q21 gains should be considered a high-risk feature in multiple myeloma receiving bortezomib therapy.

The Impact of Clone Size on the Prognostic Value of Chromosome Aberrations by Fluorescence In Situ Hybridization in Multiple Myeloma

Purpose: Accumulating evidence indicates that intratumor heterogeneity is prevalent in multiple myeloma and that a collection of multiple, genetically distinct subclones are present within the myeloma cell population. It is not clear whether the size of clonal myeloma populations harboring unique cytogenetic abnormalities carry any additional prognostic value. Experimental Design: We analyzed the prognostic impact of cytogenetic aberrations by fluorescence in situ hybridization at different cutoff values in a cohort of 333 patients with newly diagnosed myeloma and 92 patients with relapsed myeloma. Results: We found that nearly all IgH-related arrangements were observed in a large majority of the purified plasma cells; however, 13q deletion, 17p deletion, and 1q21 amplification appeared in different percentages within the malignant plasma cell population. Based on the size of subclones carrying these cytogenetic aberrations, the patients were divided into four groups: 0%–10%, 10.5%–20%, 20.5%–50%, and >50%. Receiver-operating characteristics analysis was applied to determine the optimal cutoff value with the greatest differential survival and showed that the most powerful clone sizes were 10% for 13q deletion, 50% for 17p deletion, and 20% for 1q21 gains, which provided the best possible cutoffs for predicting poor outcomes. Conclusions: Our study indicated that the impact of clone size on prognostic value varies between specific genetic abnormalities. Prognostic value was observed for even a subgroup of plasma cells harboring the cytogenetic aberration of 13q deletion and 1q21 gains; however, 17p deletion displayed the most powerful cutoff for predicting survival only if the predominant clones harbored the abnormality. Clin Cancer Res; 21(9); 2148–56. ©2015 AACR.

Suppressing miRNA-15a/-16 expression by interleukin-6 enhances drug-resistance in myeloma cells

The bone marrow microenvironment facilitates the survival, differentiation, and proliferation of myeloma (MM) cells. This study identified that microRNA-15a and -16 expressions tightly correlated with proliferation and drug sensitivity of MM cells. miRNA-15a/-16 expression in MM cells was significantly increased after treatment with cytotoxic agents. The interaction of bone marrow stromal cells (BMSC) with MM cells resulted in decreased miRNA-15a/-16 expression and promoted the survival of the MM cells. Interleukin-6 (IL-6) produced by BMSCs suppressed the expression of miRNA-15a and 16 in a time- and dose- dependent pattern, with the suppression on miRNA-15a being more significant than on miRNA-16. miRNA-15a-transfected MM cells were found to be arrested in G1/S checkpoint, and the transfected MM cells had decreased growth and survival. In conclusion, our data suggest that via suppressing miRNA-15a and -16 expressions, IL-6 secreted by BMSCs promotes drug-resistance in myeloma cells.

t(11;14) multiple myeloma: A subtype associated with distinct immunological features, immunophenotypic characteristics but divergent outcome

UNLABELLED t(11;14)(q13;q32) is the most common chromosome translocation in multiple myeloma (MM), but a consensus of clinicopathological features and impact on survival is yet to be reached. We analyzed a cohort of 350 patients with various plasma cell malignancies, including newly diagnosed MM (NDMM, n=253), relapsed/refractory MM (RRMM, n=77), as well as primary and secondary plasma cell leukemia (PCL, n=10 and n=10, respectively). RESULTS A remarkably higher frequency of t(11;14) was observed in the PCL than in the NDMM. A high incidence of t(11;14) was detected in the IgD, IgM, and nonsecretory MM. The t(11;14) MM group was associated with a significantly higher positive rate of B-lineage associated antigens CD20 and CD79a as well as the lack of CD56 expression. t(11;14) was less likely to be accompanied by 13q14 deletion than 13q14 deletion frequency in non-t(11;14) population (p=0.026), and fewer patients displaying t(11;14) were identified as belonging to the high-risk cytogenetic group due to the extremely low incidence of t(4;14) and t(14;16). As a whole, patients exhibiting t(11;14) had a comparable outcome with the control cohort in NDMM, but CD20 was able to identify two subsets of the disease with dissimilar outcomes. Among patients receiving bortezomib-based treatment, patients harboring t(11;14) without CD20 expression had a significantly shortened PFS (11.0 versus 43.0 months, p=0.005) and OS (16.5 versus 54.0 months, p=0.016) compared with patients displaying t(11;14) with CD20. Our findings suggest that although the t(11;14) plasma cell disorder displayed distinct biological, clinical and laboratory features, it was a heterogeneous disease with divergent outcome.

Targeting stem cell niche can protect hematopoietic stem cells from chemotherapy and G-CSF treatment.

IntroductionHematopoietic stem/progenitor cells (HSPCs) reside in a tightly controlled local microenvironment called bone marrow niche. The specialized microenvironment or niche not only provides a favorable habitat for HSPC maintenance and development but also governs stem cell function.MethodWe investigated the effect of cytotoxic drugs on bone marrow niche. To mimic the multiple rounds of chemotherapy followed by autologous hematopoietic stem cells (HSCs) transplantation in a clinical setting, we further verified the hypothesis that targeting the niche might improve stem cell–based therapies in mouse models.ResultsWe found that multiple rounds of cytotoxic drug treatment significantly disrupted niche and serum osteocalcin level was significantly reduced after treatment in autologous HSPCs transplanted patients (P = 0.01). In mouse models, the number of CD45−Ter119−OPN+ osteoblasts was significantly reduced after multiple rounds of chemotherapies and granulocyte colony stimulating factor (G-CSF) treatment (P < 0.01). Parathyroid hormone (PTH) or receptor activator of nuclear factor kappa-B ligand (RANKL) treatment significantly increased the number of HSCs mobilized into peripheral blood (PB) for stem cell harvesting and protected stem cells from repeated exposure to cytotoxic chemotherapy. Treatments with G-CSF and PTH significantly increased the preservation of the HSC pool (P < 0.05). Moreover, recipient mice transplanted with circulation HSPCs that were previously treated with PTH and RANKL showed robust myeloid and lymphatic cell engraftment compared to the mice transplanted with HSCs after chemotherapy or G-CSF treatment.ConclusionThese data provide new evidence that the niche may be an important target for drug-based stem cell therapy.

Features of Extramedullary Disease of Multiple Myeloma: High Frequency of P53 Deletion and Poor Survival: A Retrospective Single-Center Study of 834 Cases

BACKGROUND Multiple myeloma (MM) is a heterogeneous disease in which most patients have myeloma restricted to the bone marrow, and some patients develop extramedullary disease (EMD) at the time of diagnosis or during follow-up, and show different clinical characteristics and a dismal prognosis. PATIENTS AND METHODS We studied 834 consecutive MM patients in a single center in China and compared clinical features of patients with and without EMD. RESULTS In general, the prevalence of EMD was 4.8% at the time of diagnosis and 3.4% during follow-up, with a significant increase in recent years. MM patients with EMD at the time of diagnosis had remarkably greater prevalence of P53 deletion determined using fluorescence in situ hybridization (FISH) analysis (34.5% vs. 11.9%; P = .037) and higher level of lactate dehydrogenase (LDH) (P = .003) compared with patients without EMD. EMD relapse/progression during follow-up was correlated with EMD presentation at diagnosis, immunoglobulin (Ig)D subtype and P53 deletion in FISH analysis, but not previous treatment (thalidomide, bortizomib, or transplantation). With respect to prognosis, multivariate analysis showed that EMD was an independent adverse prognostic factor. The overall survival of patients with and without EMD at diagnosis were 16.5 and 40 months, respectively (P < .001), and the time to disease progression of the 2 groups was 11.5 and 25 months, respectively (P < .001). CONCLUSION MM patients with EMD at the time of diagnosis showed remarkably greater prevalence of P53 deletion in FISH analysis and higher LDH levels. EMD relapse/progression was correlated with EMD presentation at diagnosis, IgD subtype, and P53 deletion in FISH analysis, but not previous exposure to new drugs or transplantation. The presence of EMD involvement negatively affected survival.

Serum high expression of miR-214 and miR-135b as novel predictor for myeloma bone disease development and prognosis.

Multiple myeloma (MM) originates from malignant plasma cells, leading to multiple destructive lytic bone lesions that occur in more than 80% of MM patients. MicroRNAs have been reported to be involved in development of bone lesions in MM. However, the circulating microRNA as diagnostic and prognostic biomarkers for bone lesions has not been elucidated yet. In this study, we identified differentially expressed miRNAs that are potentially involved in myeloma-related bone disease in serum of MM patients. MiR-214 and miR-135b was shown to be increased in serum of MM patients with bone lesions. Serum level of miR-214 and miR-135b was highly correlated with the severity of lytic bone lesions and demonstrated as a diagnostic tool for identifying bone diseases based on results of a receiver operating characteristic analysis (ROC). In addition, patients with high levels of serum miR-214 had a dismal survival with significantly shortened progression free survival (PFS) and overall survival (OS). Interestingly, bisphosphonates treatment significantly extended PFS and OS in patients with higher level of miR-214 comparing to patients without bisphosphonates treatment. Taken together, our findings revealed the significance of circulating miR-214 and miR-135b levels in detection of bone disease and in prediction of prognosis of patients with multiple myeloma, suggesting its potential clinical applications. The result of this study also set the foundation for searching more circulating miRNA as biomarker for tumor bone lesions.

MicroRNA-15a/16-1 cluster located at chromosome 13q14 is down-regulated but displays different expression pattern and prognostic significance in multiple myeloma

MiRNA-15a/16-1 cluster located at chromosome 13q14 has been confirmed to regulate critical genes associated with cell proliferation, apoptosis and drug resistance in multiple myeloma (MM). However, little is known about their expression pattern and prognostic value in MM patients. In this study, we have analyzed the expression levels of miR-15a/16-1 in 117 MM patients (90 newly diagnosed, 11 relapsed and 16 remission patients) and 19 health donors (HDs) by quantitative real-time PCR. Our results indicated that the expression levels of miR-15a and 16-1 were down-regulated in newly diagnosed MM patients as compared to HDs (P = 0.025; P < 0.001) and independent of del(13q14). Downregulation of miR-15a was significantly associated with disease progression and poor prognosis while miR-16-1 seemed to be a good diagnostic marker to distinguish MM from HDs with area under the curve (AUC) of 0.864, sensitivity of 100% and specificity of 73%. Furthermore, patients with miR-15a < 2.35 (low expression group) had significantly shorter PFS (P < 0.001) and OS (P < 0.001). After adjustment of the established prognostic variables including del(13q), del(17p), amp(1q21) and high risk genetic abnormality, low miR-15a expression (<2.35) was still a powerful independent predictor for PFS (P = 0.008) and OS (P = 0.038). In addition, miR-15a combined with high β2-MG and high risk genetic abnormality can further identify the high-risk subpopulations. Therefore, our data suggest that the expression patterns of miR-15a/16-1 are different in MM patients, and miR-15a seems to be linked with disease progression and prognosis while miR-16-1 acts as a valuable diagnostic marker.

Further stratification of patients with multiple myeloma by International Staging System in combination with ratio of serum free κ to λ light chains.

The serum free light chain (sFlc) levels were measured for 122 Chinese patients with newly diagnosed symptomatic multiple myeloma (NDSMM), and κ/λ ratios (rFlc) were calculated. The data were analyzed for the roles of sFlc and rFlc in the diagnosis and prognosis of MM. Abnormal sFlc and/or rFlc were detected in 99.2% of patients, demonstrating that the FLC assay is much more sensitive than the commonly used methods. Baseline sFlc and rFlc successfully predicted the overall survival (OS). The median OS was not reached (NR) versus 23 months for the low sFLC group (sFLC-κ  180 mg/L or sFLC-λ  592.5 mg/L) and high sFLC group (sFLC-κ ≥ 180 mg/L or sFLC-λ ≥ 592.5 mg/L) (p = 0.001), and NR versus 21 months for the low rFLC group (0.04 ≤ rFLC ≤ 25) and high rFLC group (p 0.001), respectively. Interestingly, the significant differences in OS between the low and high rFLC groups were not changed by bortezomib chemotherapy. In addition, patients were further stratified by three novel poor-prognosis factors (β2-microglobulin [β2-MG]  3.5 mg/L, albumin [ALB]  35 g/L, rFLC  25 or rFLC  0.04) that were developed from combination of the rFlc with the International Staging System (ISS): the low risk group (no factor), the low-intermediate risk group (one factor), the high-intermediate risk group (two factors) and the high risk group (three factors). The median OS for those groups was NR, NR, 24 months and 13 months, respectively (p 0.05). In conclusion, the sFLC assay was highly sensitive in the diagnosis of MM in Chinese patients. The prognostic potential of the ISS may be improved with the addition of rFLC.

Downregulated miR-33b is a novel predictor associated with disease progression and poor prognosis in multiple myeloma

MiRNAs located at chromosome fragile sites play important roles in regulating critical genes associated with myeloma pathogenesis, disease progression and drug resistance. Our previous results have identified miR-33b (located in chromosome 17p) was one of the dysregulated miRNAs in the sera of newly diagnosed MM patients. However, little is known about its expression pattern in myeloma tumor cells and its prognostic value in MM patients. In the present study, we investigated the expression pattern of miR-33b in 58 newly diagnosed, 11 relapsed, 12 remission MM patients and 18 health donors by quantitative real-time PCR. Our results showed the expression of miR-33b was obviously down-regulated in newly diagnosed and relapsed MM patients compared to remission patients and health donors (p<0.001). Moreover, patients with del(13q), del(17p), t(4;14) and high-risk genetic abnormalities have lower expression levels of miR-33b compared to patients without those of abnormalities (p=0.032, 0.018, 0.034, 0.005). Survival analysis showed patients with miR-33b low expression had significantly shortened PFS (p=0.016) and OS (p=0.033) and might be associated with drug resistance to bortezomib-based treatment. Our data suggest that down-regulated miR-33b might be a novel predictor associated with disease progression and poor prognosis in MM.