Quantitative monitoring of cyclin D1 expression: A molecular marker for minimal residual disease monitoring and a predictor of the disease outcome in patients with mantle cell lymphoma

Noncoding RNAs in B cell non-Hodgkins lymphoma

B-cell non-Hodgkins lymphomas (BCNHLs) are a category of B-cell cancers that show heterogeneity. These blood disorders are derived from different levels of B-cell maturity. Among NHL cases, ∼80-90 % are derived from B-cells. Recent studies have demonstrated that noncoding RNAs (ncRNAs) contribute to almost all parts of mechanisms and are essential in tumorigenesis, including B-cell non-Hodgkins lymphomas. The study of ncRNA dysregulations in B-cell lymphoma unravels important mysteries in lymphoma's molecular etiology. It seems also necessary for discovering novel trials as well as investigating the potential of ncRNAs as markers for their diagnosis and prognosis. In the current study, we summarize the role of ncRNAs involving miRNAs, long noncoding RNAs, as well as circular RNAs in the development or progression of BCNHLs.

MicroRNAs as Biomarkers of B-cell Lymphoma

B-cell lymphomas represent a diverse group of neoplasms classified primarily by histopatholgy and are often challenging to accurately diagnose. Despite having been recognized less than 20 years ago, microRNAs (miRNAs) have emerged as one of the most promising class of cancer molecular biomarkers and are particularly attractive as they can be readily detected in formalin-fixed paraffin-embedded biopsy material and biological fluids such as blood. Many of the identified B-cell lymphoma miRNA biomarkers also play crucial regulatory roles in normal B-cell development. Below we consider the identity, function, and biomarker potential of miRNAs in B-cell lymphoma and most importantly the barriers that remain to be overcome if they are really to become part of routine clinical practice.

Cyclin D1 mRNA as a molecular marker for minimal residual disease monitoring in patients with mantle cell lymphoma

Chromosomal translocation t(11;14)(q13;q32) is a characteristic molecular marker of mantle cell lymphoma (MCL) and leads to the fusion of the immunoglobulin heavy chain enhancer-promoter with the cyclin D1 gene. Both aberrant cyclin D1 expression and underlying chromosomal aberration may be used as molecular targets for monitoring minimal residual disease (MRD). The present study aims to assess the usefulness of quantitative cyclin D1 gene expression compared to the standardised but more technologically demanding DNA-based method for immunoglobulin heavy chain (IGH) or t(11;14) clone-specific gene rearrangement quantification in a cohort of bone marrow (BM) and peripheral blood (PB) samples from patients with MCL. We simultaneously evaluated DNA-MRD and cyclin D1 expression levels in 234 samples from 57 patients. We observed that both in DNA-MRD positive and negative BM/PB pairs from the same time points the expression levels of cyclin D1 are lower in PB than in BM (median 19×, BM/PB range 0.41-352). The correlation of cyclin D1 transcript levels with DNA-MRD or with flow cytometry was good only in samples with a very high infiltration. In DNA-MRD-negative BM samples, we observed a significant heterogeneity of cyclin D1 expression (in the range of more than three orders of magnitude). This is in contrast to previous reports demonstrating the usefulness of cyclin D1 for MRD monitoring that did not use DNA-based method as a reference. In PB, the specificity of cyclin D1 expression was better due to a lower physiological background. In conclusion, we show that cyclin D1 is unsuitable for MRD monitoring in BM.

Cyclin D1 (CCND1) messenger RNA expression as assessed by real-time PCR contributes to diagnosis and follow-up control in patients with mantle cell lymphoma

Molecular diagnosis of mantle cell lymphoma (MCL) can be difficult because the t(11;14)/IGH@-CCND1 is extremely heterogeneous at the DNA level. Aiming to establish a reliable molecular tool that could be easily implemented in routine diagnostics, we developed a new real-time polymerase chain reaction (PCR) assay for CCND1 expression measurement and evaluated 451 cases: 142 MCL, 76 chronic lymphocytic leukemia, 20 hairy cell leukemia, 13 hairy cell leukemia-variant, 20 splenic marginal zone lymphoma, 91 other mature B-cell neoplasms, 29 other hematologic neoplasms, and 60 healthy individuals. Sensitivity of the real-time PCR assay was up to 10(-4). In t(11;14)/IGH@-CCND1 positive lymphoma samples (n = 150), median %CCND1/ABL1 expression level was 178.2 (range: 1.5-4, 152.0). Normalized by t(11;14)/IGH@-CCND1 positive cells as determined by fluorescence in situ hybridization IGH@-CCND1 positive samples showed a median %CCND1/ABL1 of 445.8 (range: 17.9-4,848.5). A normalized %CCND1/ABL1 expression of at least 17.0 was chosen as threshold for CCND1 positivity. For unnormalized samples, the positive detection rate of t(11;14)/IGH@-CCND1 by CCND1 expression was 87.3%. Healthy individuals had low %CCND1/ABL1 (median, 1.1; range, 0.0-7.8). The negative predictive value for exclusion of a t(11;14)/IGH@-CCND1 by CCND1 expression was 95.3% by the above threshold. %CCND1/ABL1 was higher in MCL than in the remaining B-cell lymphomas (mean ± SD, 392.9 ± 685.3 vs. 46.0 ± 305.0; p < 0.001). In 66 follow-up samples, CCND1 showed 2.5-3.5 log reduction after chemotherapy and increase at relapse. CCND1 expression could serve as adjunct to other techniques in diagnosis and follow-up of B-cell lymphomas.

Clinical practice guidelines for diagnosis, treatment, and follow-up of patients with mantle cell lymphoma. Recommendations from the GEL/TAMO Spanish Cooperative Group

Mantle cell lymphoma (MCL) is considered a distinct type of B-cell lymphoma genetically characterized by the t(11;14) translocation and cyclin D1 overexpression. There is also a small subset of tumors negative for cyclin D1 expression that are morphologically and immunophenotypically indistinguishable from conventional MCL. Although in the last decades, the median overall survival of patients with MCL has improved significantly, it is still considered as one of the poorest prognoses diseases among B-cell lymphomas. Election of treatment for patients with MCL is complex due to the scarcity of solid evidence. Current available data shows that conventional chemotherapy does not yield satisfactory results as in other types of B-cell lymphomas. However, the role of other approaches such as autologous or allogenic stem cell transplantation, immunotherapy, the administration of consolidation or maintenance schedules, or the use of targeted therapies still lack clear indications. In view of this situation, the Spanish Group of Lymphomas/Autologous Bone Marrow Transplantation has conducted a series of reviews on different aspects of MCL, namely its diagnosis, prognosis, first-line and salvage treatment (both in young and elderly patients), new targeted therapies, and detection of minimal residual disease. On the basis of the available evidence, a series of recommendations have been issued with the intention of providing guidance to clinicians on the diagnosis, treatment, and monitoring of patients with MCL.

A highly sensitive and specific qPCR assay for quantification of the biomarker SOX11 in mantle cell lymphoma

OBJECTIVES

Mantle cell lymphoma (MCL) is one of the most heterogeneous lymphoid neoplasms with a variable course of disease. Although t(11;14)(q13;q32) is the hallmark of MCL resulting in cyclin D1 (CCND1) overexpression in 90% of patients, this is difficult to validate by immunohistochemistry. We hypothesised that SOX11 could be a robust molecular biomarker for MCL.

METHODS

We have developed very sensitive and specific RT-qPCR assay employing a poly-A specific RT primer to circumvent contamination from gDNA caused by the intron-less nature of SOX11.

RESULTS

We found a significant difference between the expression levels of SOX11 in patients with MCL at diagnosis (n = 21) and in healthy donors (n = 18) (blood: P < 0.0001; marrow: P = 0.0001). SOX11 expression of very low levels close to the assay sensitivity was detected in only 2 of 18 healthy donors, while low levels of CCND1 expression was observed in all blood and 12 of 13 marrow samples within the defined detection limit of Cq = 40. In spiking experiments of the GRANTA-519 MCL cell line into mononuclear cells from normal donor, the sensitivity of the SOX11 assay was found to be 2 × 10(-4) , while the sensitivity of the CCND1 assay was estimated to 2 × 10(-3) because of the normal background expression. In longitudinal sampling from patients with MCL the minimal residual disease (MRD) values based on the SOX11 expression mirrored the clinical disease development.

CONCLUSION

This SOX11 RT-qPCR assay could be a useful tool for MRD monitoring in patients with MCL.

Minimal residual disease detection in mantle cell lymphoma: technical aspects and clinical relevance

The prognostic impact of minimal residual disease (MRD) has been demonstrated for several hematologic malignancies. While in acute lymphoblastic leukemias MRD assessment by polymerase chain reaction (PCR)-based methods has been established as an important tool for clinical risk assessment and is part of clinical management, data demonstrating a prognostic value of MRD in mantle cell lymphoma (MCL) were sparse and results from randomized trials have been published only recently. In the present review technical aspects of different MRD detection methods are discussed, as well as the prognostic relevance of MRD in the context of clinical trials in patients with MCL. Furthermore, recommendations are given for workflow and useful implication of MRD in future clinical trials design.

Mantle cell lymphoma: transcriptional regulation by microRNAs

Mantle cell lymphoma (MCL) pathogenesis is still partially unexplained. We investigate the importance of microRNA (miRNA) expression as an additional feature that influences MCL pathway deregulation and may be useful for predicting patient outcome. Twenty-three MCL samples, eight cell lines and appropriate controls were screened for their miRNAs and gene expression profiles and DNA copy-number changes. MCL patients exhibit a characteristic signature that includes 117 miRNA (false discovery rate <0.05). Combined analysis of miRNAs and the gene expression profile, paired with bioinformatics target prediction (miRBase and TargetScan), revealed a series of genes and pathways potentially targeted by a small number of miRNAs, including essential pathways for lymphoma survival such as CD40, mitogen-activated protein kinase and NF-kappaB. Functional validation in MCL cell lines demonstrated NF-kappaB subunit nuclear translocation to be regulated by the expression of miR-26a. The expression of 12 selected miRNAs was studied by quantitative PCR in an additional series of 54 MCL cases. Univariate analysis identified a single miRNA, miR-20b, whose lack of expression distinguished cases with a survival probability of 56% at 60 months. In summary, using a novel bioinformatics approach, this study identified miRNA changes that contribute to MCL pathogenesis and markers of potential utility in MCL diagnosis and clinical prognostication.