Current regimens and novel agents for mantle cell lymphoma

Anti-human CD99 antibody exerts potent antitumor effects in mantle cell lymphoma

CD99 is a surface molecule expressed on various cell types including cancer cells. Expression of CD99 on multiple myeloma is associated with CCND1-IGH fusion/t(11;14). This translocation has been reported to be a genetic hallmark of mantle cell lymphoma (MCL). MCL is characterized by overexpression of cyclin D1 and high tumor proliferation. In this study, high expression of CD99 on MCL cell lines was confirmed. Our generated anti-CD99 monoclonal antibody (mAb), termed MT99/3, exerted potent antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) activities against mantle B-cell lymphoma without direct cytotoxic effects. The anti-tumor activities of mAb MT99/3 were more effective in MCL than in other B-cell lymphomas. Moreover, in a mouse xenograft model using Z138 MCL cell line, treatment of mAb MT99/3 reduced tumor development and growth. Our study indicated that mAb MT99/3 is a promising immunotherapeutic candidate for mantle cell lymphoma therapy.

MicroRNA-506 inhibits the proliferation and invasion of mantle cell lymphoma cells by targeting B7H3

BACKGROUND

Aberrant expression of B7 homologue 3 (B7H3) has been observed in various malignancies. Our previous study demonstrated that knocking down of B7H3 inhibited cell proliferation, invasion and enhanced the therapeutic efficacy of chemotherapy in mantle cell lymphoma (MCL). However, the mechanism regulating of B7H3 expression remains unknown. Here, we present a new regulatory microRNA of B7H3, miR-506, that directly targets B7H3 and may play an inhibitory role in MCL progression.

METHODS

The expression of miR-506 and B7H3 was investigated by real-time quantitative PCR (RT-qPCR). B7H3 was confirmed to be a novel direct target gene of miR-506 by a dual-luciferase assay and western blot analysis. MiR-506 overexpression in the Maver and Z138 MCL cell lines was established using lentiviral transduction. Cell counting kit-8, flow cytometry and Transwell assays were used to detect changes in cell proliferation, cycle distribution, migration and invasion, respectively.

RESULTS

The RT-qPCR results showed that miR-506 was expressed at a low level, while B7H3 was overexpressed in MCL patients and cell lines. By using a bioinformatics analysis combined with a dual-luciferase assay, we determined that miR-506 could target the 3'-untranslated region (3'-UTR) of B7H3 mRNA. Moreover, miR-506 had a negative regulatory effect on B7H3 expression according to the western blotting and RT-qPCR results. In terms of function, increased expression of miR-506 led to reduced MCL cell proliferation, invasion and migration, caused cell cycle arrested at G0/G1 phase, similar to the effects of B7H3 knockdown. Furthermore, we measured the expression of invasion-related proteins by western blotting and found that miR-506 could reduce MMP-2 and MMP-9 expression in MCL cells. Rescue experiments suggested that the restoration of B7H3 expression in MCL cells reversed the inhibition of proliferation and invasion induced by miRNA-506 overexpression.

CONCLUSIONS

Our findings suggest that miR-506 functions as a tumor suppressor miRNA and plays a significant role in inhibiting human MCL cell proliferation and metastasis by suppressing B7H3 expression.

Positron Emission Tomography-based Analysis Can Accurately Predict Bone Marrow Involvement With Mantle Cell Lymphoma

INTRODUCTION

Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma and requires both bone marrow biopsy and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) to correctly stage the disease at diagnosis. However, accurate identification of bone marrow involvement by lymphoma on FDG PET/CT scans has not been previously demonstrated. We hypothesized that a voxel-based analysis of the iliac bones on the FDG PET/CT scan might provide insight into bone marrow involvement.

PATIENTS AND METHODS

A retrospective cohort study of patients with a diagnosis of MCL who had undergone both single iliac bone marrow biopsy and FDG-PET/CT scan from 1 study site were included in the development phase (n = 10). An additional 12 patients from a second institution were included in the validation phase. Using a semiautomated workflow, a voxel-based data set of FDG uptake within the bilateral iliac bones was captured for each patient. In the development phase, empirical receiver operating characteristic curves for each data set were fit. We then identified the standardized uptake value (SUV) threshold cutpoints at which the sensitivity and specificity were optimized to 100%. In the validation phase, we evaluated the performance of these candidate SUV threshold cutpoints in 15 additional patients from a second institution.

RESULTS

We found that 1 cutpoint, > 38% of voxels with activity < 0.95, outperformed all the other candidate cutpoints, correctly classifying all patients except for 1 (overall sensitivity, 100%; specificity, 87.5%).

CONCLUSION

The ability to correctly identify bone marrow involvement using FDG PET/CT-based voxel analysis provides promise as a novel noninvasive method of accurate staging.

Current trials for frontline therapy of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare and incurable subtype of non-Hodgkin’s lymphoma that generally affects older individuals. However, the use of high-dose therapy and autologous stem cell transplant has improved significantly the prognosis of this hematological malignancy, but at the cost of increased toxicities, such as acute toxic death and secondary malignancies. But thanks to a rising understanding of the biology of MCL, the explosion of specifically targeted new efficacious agents, immunotherapy agents, and cellular therapies in the frontline setting, the prognosis of MCL is expected to improve dramatically.

The initial treatment of MCL is currently not standardized and the therapeutic landscape of MCL is rapidly evolving. This review provides an extensive overview of the current frontline therapy trials for MCL and presents the results of innovative regimen, including some integrating novel agents and desintensified chemotherapy.

Mantle cell lymphoma: involvement of nodal and extranodal sites in the head and neck, with multifocal oral lesions

Mantle cell lymphoma (MCL) is a malignant B-cell neoplasm, which comprises monomorphic and small- to medium-sized mantle zone-derived lymphoid cells. It is characterized by chromosomal translocation t(11;14)(q13;q32) and CCND1 truncation, resulting in cell cycle deregulation. It is an aggressive type of non-Hodgkin lymphoma with a propensity to present with extranodal involvement. This study shows the case of an 80-year-old Caucasian male who complained of a 2-month progressive swelling on the right side of his face. The magnetic resonance imaging exam showed multifocal involvement of the head and neck, including oral manifestations, bilateral parotid glands, palate, tongue, and floor of the mouth. An incisional biopsy of the tumor mass was performed. The morphological and immunophenotypic findings were consistent with the diagnosis of MCL. The patient died 4 months later, without any chance of undergoing a therapeutic approach. Although MCL is a rare condition, it should be subjected to a differential diagnosis when affecting the maxillofacial area. Imaging exams and both immunohistochemical and morphological analyses are needed to reach the correct diagnosis. Here, we present an unusual MCL with multifocal involvement of the head and neck.

Structural optimization elaborates novel potent Akt inhibitors with promising anticancer activity

Targeting of Akt has been validated as a well rationalized approach to cancer treatment, and represents a promising therapeutic strategy for aggressive hematologic malignancies. We describe herein an exploration of novel Akt inhibitors for cancer therapy through structural optimization of previously described 4-(piperazin-1-yl)-7H-pyrrolo[2,3-d]pyrimidine derivatives. Our studies yielded a novel series of pyrrolopyrimidine based phenylpiperidine carboxamides capable of potent inhibition of Akt1. Notably, 10h exhibited robust antiproliferative effects in both mantle cell lymphoma cell lines and primary patient tumor cells. Low micromolar doses of 10h induced cell apoptosis and cell cycle arrest in G₂/M phase, and significantly downregulated the phosphorylation of Akt downstream effectors GSK3β and S6 in Jeko-1 cells.

Therapeutic potential of targeting sphingosine kinases and sphingosine 1-phosphate in hematological malignancies

Sphingolipids, such as ceramide, sphingosine and sphingosine 1-phosphate (S1P) are bioactive molecules that have important functions in a variety of cellular processes, which include proliferation, survival, differentiation and cellular responses to stress. Sphingolipids have a major impact on the determination of cell fate by contributing to either cell survival or death. Although ceramide and sphingosine are usually considered to induce cell death, S1P promotes survival of cells. Sphingosine kinases (SPHKs) are the enzymes that catalyze the conversion of sphingosine to S1P. There are two isoforms, SPHK1 and SPHK2, which are encoded by different genes. SPHK1 has recently been implicated in contributing to cell transformation, tumor angiogenesis and metastatic spread, as well as cancer cell multidrug-resistance. More recent findings suggest that SPHK2 also has a role in cancer progression. This review is an overview of our understanding of the role of SPHKs and S1P in hematopoietic malignancies and provides information on the current status of SPHK inhibitors with respect to their therapeutic potential in the treatment of hematological cancers.

Ibrutinib for mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare and aggressive form of non-Hodgkin lymphoma. Ibrutinib is a first-in-class, oral inhibitor of Bruton's tyrosine kinase which acts by downstream inhibition of the B-cell receptor. Early clinical trials have demonstrated excellent tolerability and a modest side-effect profile in relapsed/refractory MCL. Although the majority of disease responses are partial, efficacy data are impressive with more than two-thirds of patients demonstrating a durable response. This article focuses on all aspects of ibrutinib in the context of MCL, including a summary of the basic pharmacology and pharmacokinetics; a review of the safety and efficacy data published to date and a discussion of the future implications in MCL.

NK Cell Subgroups, Phenotype, and Functions After Autologous Stem Cell Transplantation

High-dose chemotherapy with consecutive autologous stem cell transplantation (autoSCT) is a well-established treatment option for patients suffering from malignant lymphoma or multiple myeloma. Natural killer (NK) cells are an important part of the immune surveillance, and their cell number after autoSCT is predictive for progression-free and overall survival. To improve knowledge about the role of NK cells after autoSCT, we investigated different NK cell subgroups, their phenotype, and their functions in patients treated with autoSCT. Directly after leukocyte regeneration (>1000 leukocytes/μl) following autoSCT, CD56⁺⁺ NK cells were the major NK cell subset. Surprisingly, these cells showed unusually high surface expression levels of CD57 and killer Ig-like receptors (KIRs) compared to expression levels before or at later time points after autoSCT. Moreover, these NK cells strongly upregulated KIR2DL2/3/S2 and KIR3DL1, whereas KIR2DL1/S1 remained constant, indicating that this cell population arose from more immature NK cells instead of from activated mature ones. Remarkably, NK cells were already able to degranulate and produce IFN-γ and MIP-1β upon tumor interaction early after leukocyte regeneration. In conclusion, we describe an unusual upregulation of CD57 and KIRs on CD56⁺⁺ NK cells shortly after autoSCT. Importantly, these NK cells were functionally competent upon tumor interaction at this early time point.

Arsenic trioxide rewires mantle cell lymphoma response to bortezomib

Although most of the mantle cell lymphoma (MCL) patients initially responded well to bortezomib (BTZ), the dose-dependent toxicities have greatly limited the application of BTZ to MCL. To investigate the efficacy and mechanism of arsenic trioxide (ATO) with BTZ in inducing apoptosis of MCL cells, two MCL cell lines, along with primary cells from MCL patients (n = 4), were used. Additionally, the NOD-SCID mice xenograft model of Jeko-1 cells was established to study the anti-MCL mechanisms in an in vivo setting. ATO treatment highly improved BTZ capacity to inhibit proliferation and induce apoptosis of MCL cells. Furthermore, the interaction of Noxa and Mcl-1 leads Bak to release from Mcl-1 or from Bcl-xl, which could further activate Bak and Bax and then induce cell apoptosis. We also found that when lower doses of BTZ were used in combination with ATO, more effective proapoptotic effects in both the cell lines and the primary cells were obtained compared to the effects of BTZ used alone at higher doses. Simultaneously, the combination of these two drugs delayed the tumor growth in mice more effectively than BTZ alone. The cooperative anti-MCL effects of this combination therapy both in vitro and in vivo strongly provided a new strategy to the clinical treatment of MCL.

A critical appraisal of ibrutinib in the treatment of mantle cell lymphoma and chronic lymphocytic leukemia

Although chemo-immunotherapy remains at the forefront of first-line treatment for mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL), small molecules, such as ibrutinib, are beginning to play a significant role, particularly in patients with multiply relapsed or chemotherapy-refractory disease and where toxicity is an overriding concern. Ibrutinib is a first-in-class, oral inhibitor of Bruton's tyrosine kinase, which functions by irreversible inhibition of the downstream signaling pathway of the B-cell receptor, which normally promotes cell survival and proliferation. Early clinical trials have demonstrated excellent tolerability and a modest side-effect profile even in elderly and multiply pretreated patient cohorts. Although the majority of disease responses tend to be partial, efficacy data have also been encouraging with more than two-thirds of patients with CLL and MCL demonstrating a durable response, even in the high-risk disease setting. Resistance mechanisms are only partially understood and appear to be multifactorial, including the binding site mutation C481S, and escape through other common cell-signaling pathways. This article appraises the currently available data on safety and efficacy from clinical trials of ibrutinib in the management of MCL and CLL, both as a single agent and in combination with other therapies, and considers how this drug is likely to be used in future clinical practice.

A novel vaccine for mantle cell lymphoma based on targeting cyclin D1 to dendritic cells via CD40

Background

Mantle cell lymphoma (MCL) is a distinct clinical pathologic subtype of B cell non-Hodgkin’s lymphoma often associated with poor prognosis. New therapeutic approaches based on boosting anti-tumor immunity are needed. MCL is associated with overexpression of cyclin D1 thus rendering this molecule an interesting target for immunotherapy.

Methods

We show here a novel strategy for the development of recombinant vaccines carrying cyclin D1 cancer antigens that can be targeted to dendritic cells (DCs) via CD40.

Results

Healthy individuals and MCL patients have a broad repertoire of cyclin D1-specific CD4⁺ and CD8⁺ T cells. Cyclin D1-specific T cells secrete IFN-γ. DCs loaded with whole tumor cells or with selected peptides can elicit cyclin D1-specific CD8⁺ T cells that kill MCL tumor cells. We developed a recombinant vaccine based on targeting cyclin D1 antigen to human DCs via an anti-CD40 mAb. Targeting monocyte-derived human DCs in vitro with anti-CD40-cyclin D1 fusion protein expanded a broad repertoire of cyclin D1-specific CD4⁺ and CD8⁺ T cells.

Conclusions

This study demonstrated that cyclin D1 represents a good target for immunotherapy and targeting cyclin D1 to DCs provides a new strategy for mantle cell lymphoma vaccine.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-015-0131-7) contains supplementary material, which is available to authorized users.

B7-H3 silencing inhibits tumor progression of mantle cell lymphoma and enhances chemosensitivity

B7-H3 (CD276), known as a member of B7 immunoregulatory family, is a type I transmembrane glycoprotein aberrantly expressed in numerous types of cancer and associated with poor prognosis. However, the role of B7-H3 in oncogenesis and chemosensitivity of mantle cell lymphoma (MCL) remains unknown. We determined the effects of downregulating B7-H3 expression on tumor progression and the sensitivity of chemotherapeutic drug in mantle cell lymphoma. B7-H3 knockdown was performed using lentivirus transduction in the Maver and Z138 mantle cell lymphoma cell lines, respectively. The effects of B7-H3 on cell proliferation, cycle, migration and invasion were investigated by CCK-8 assay, methyl cellulose colony forming assay, PI staining, and Transwell assays in vitro. By establishing Maver and Z138 xenograft models, the effects of B7-H3 on tumorigenicity were observed, and Ki-67 and PCNA was detected by immunohistochemistry. The downregulation of B7-H3 significantly decreased tumor proliferation in MCL in vitro and in vivo. In the B7-H3 knockdown groups of Maver and Z138 xenograft models, the mean inhibition rate of tumor growth was 59.1 and 65.0% (p=0.010 and 0.003), and the expression of both Ki-67 and PCNA were significantly lower, respectively. After B7-H3 silencing, the cell cycles of Maver and Z138 were both arrested at G0/G1 phase, and the cell migration rates and invasion capacity were decreased as well. Moreover, the impacts of B7-H3 RNAi on the antitumor effect of chemotherapy drugs were determined with CCK-8 and Annexin V-FITC/PI assays in vitro and with xenograft models in vivo. The silencing of B7-H3 increased the sensitivity of Maver and Z138 cells to rituximab and bendamustine and enhanced the drug-induced apoptosis, respectively. Our study demonstrates for the first time that B7-H3 promotes mantle cell lymphoma progression and B7-H3 knockdown significantly enhances the chemosensitivity. This may provide a new therapeutic approach to mantle cell lymphoma.