Dehui Zou

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.

MicroRNA-223 expression is uniformly down-regulated in B cell lymphoproliferative disorders and is associated with poor survival in patients with chronic lymphocytic leukemia

Abstract MicroRNA-223 (miR-223) expression has been demonstrated to be stage-specific in B cell differentiation and associated with the outcome of chronic lymphocytic leukemia (CLL). However, the expression pattern of miR-223 in B cell lymphoproliferative disorders and its association with the outcome of Chinese patients with CLL have not been investigated. In this study, we demonstrated that miR-223 expression was significantly decreased in CLL, mantle cell lymphoma (MCL) and splenic marginal zone lymphoma (SMZL). In CLL, miR-223 expression decreased significantly with progression from early to advanced clinical stages and was significantly lower in patients with elevated β2-microglobulin, unmutated immunoglobulin variable heavy chain (IgVH) gene or with disease progression or death. Using a cut-off determined by receiver operating characteristic (ROC) analysis optimizing concordance with IgVH mutational status, miR-223-negative and -positive groups were defined for 22 and 31 patients, respectively. The median progression-free survival (PFS) and overall survival of the miR-223-negative group were 13 and 40 months, respectively, significantly shorter than for the miR-223-positive group (both not reached; p = 0.002 and p = 0.018, respectively). Multivariate analysis revealed that the absence of miR-223 was the only independent factor capable of predicting shorter PFS. In conclusion, miR-223 is uniformly down-regulated in B-LPDs and is a useful prognostic factor for patients with CLL.

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.

A pivotal role of bone remodeling in granulocyte colony stimulating factor induced hematopoietic stem/progenitor cells mobilization

The majority of hematopoietic stem/progenitor cells (HSPCs) reside in bone marrow (BM) surrounded by a specialized environment, which governs HSPC function. Here we investigated the potential role of bone remodeling cells (osteoblasts and osteoclasts) in homeostasis and stress‐induced HSPC mobilization. Peripheral blood (PB) and BM in steady/mobilized state were collected from healthy donors undergoing allogeneic transplantation and from mice treated with granulocyte colony stimulating factor (G‐CSF), parathyroid hormone (PTH), or receptor activator of nuclear factor kappa‐B ligand (RANKL). The number and the functional markers of osteoblasts and osteoclasts were checked by a series of experiments. Our data showed that the number of CD45−Ter119− osteopontin (OPN)+ osteoblasts was significantly reduced from 4,085 ± 135 cells/femur on Day 0 to 1,032 ± 55 cells/femur on Day 5 in mice (P = 0.02) and from 21.38 ± 0.66 on Day 0 to 14.78 ± 0.65 on Day 5 in healthy donors (P < 0.01). Decrease of osteoblast number leads to reduced level of HSPC mobilization regulators stromal cell‐derived factor‐1 (SDF‐1), stem cell factor (SCF), and OPN. The osteoclast number at bone surface (OC.N/B.s) was significantly increased from 1.53 ± 0.12 on Day 0 to 4.42 ± 0.46 on Day 5 (P < 0.01) in G‐CSF‐treated mice and from 0.88 ± 0.20 on Day 0 to 3.24 ± 0.31 on Day 5 (P < 0.01) in human. Serum TRACP‐5b level showed a biphasic trend during G‐CSF treatment. The ratio of osteoblasts number per bone surface (OB.N/B.s) to OC.N/B.s was changed after adding PTH plus RANKL during G‐CSF treatment. In conclusion, short term G‐CSF treatment leads to reduction of osteoblasts and stimulation of osteoclasts, and interrupting bone remodeling balance may contribute to HSPC mobilization. J. Cell. Physiol.

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.

Additional chromosomal abnormalities and their prognostic significance in adult Philadelphia-positive acute lymphoblastic leukemia: with or without imatinib in chemotherapy

The study analyzed the characteristics and prognostic significance of additional chromosomal abnormalities in 110 Chinese adults with Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukemia (ALL). Secondary aberrations were present in 60.9% of the cases. All chromosomes were involved in secondary aberrations, and chromosomes 9, 7, 21, 18, and 14 were most frequently abnormal. Fifty of 110 patients (45.5%) had at least one normal metaphase cell in their chromosome preparations at diagnosis. Patients with additional aberrations had shorter disease-free survival (DFS) and overall survival (OS) in chemotherapy combined with imatinib (ICT) group and only shorter DFS in conventional chemotherapy (CT) group. The existence of normal metaphase cells was associated with a superior survival in CT group, but not in ICT group. Patients with loss of chromosomes 7, 7p, 9, and 9p had inferior outcome compared to patients with other secondary aberrations and those without secondary aberrations, in both CT and ICT group.

Elevated neutrophil-to-lymphocyte ratio and monocyte-to-lymphocyte ratio and decreased platelet-to-lymphocyte ratio are associated with poor prognosis in multiple myeloma

Elevated inflammatory markers are associated with poor outcomes in various types of cancers; however, their clinical significance in multiple myeloma (MM) have seldom been explored. This study investigated the prognostic relevance of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) in MM. Totally 559 MM patients were included in this study. NLR, PLR and MLR were calculated from whole blood counts prior to therapy. Kaplan-Meier curves and multivariate Cox proportional models were used for the evaluation of the survival. It has shown that newly diagnosed MM patients were characterized by high NLR and MLR. Elevated NLR and MLR and decreased PLR were associated with unfavorable clinicobiological features. Applying cut-offs of 4 (NLR), 100 (PLR) and 0.3 (MLR), elevated NLR, MLR and decreased PLR showed a negative impact on outcome. Importantly, elevated NLR and decreased PLR were independent prognostic factors for progression-free survival. Thus, elevated NLR and MLR, and decreased PLR predict poor clinical outcome in MM patients and may serve as the cost-effective and readily available prognostic biomarkers.

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.