Progress in mantle-cell lymphoma

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.

Modulation of p73 isoforms expression induces anti-proliferative and pro-apoptotic activity in mantle cell lymphoma independent of p53 status

Mantle cell lymphoma (MCL) is characterized by a clinically aggressive course with frequent relapse and poor survival. The p53 pathway is frequently dysregulated and p53 status predicts clinical outcome. In this report, we investigated whether modulation of p73 isoforms by diclofenac inhibits cell growth, induces apoptosis and/or cell cycle arrest in MCL relative to p53 status. Wild-type p53 [Granta-519 and JVM-2], mutant p53 [Jeko-1 and Mino-1] expressing cells, therapy resistant cell lines, and primary human cells isolated from MCL patients were used. Overexpression of pro-apoptotic TAp73 enhanced MCL cell apoptosis. Diclofenac induced a concentration- and duration-dependent increase in TAp73, cell cycle arrest, cell death, and inhibited MCL cell growth independent of p53 status. Diclofenac treatment was associated with increased activity of caspases 3, 7, and 8 and induction of p53 transcriptional target genes. These studies demonstrate the potential for diclofenac as novel therapeutic agent in MCL independent of p53 status.

Synergistic suppression of the PI3K inhibitor CAL-101 with bortezomib on mantle cell lymphoma growth

Objective

To investigate the effects of CAL-101, particularly when combined with bortezomib (BTZ) on mantle cell lymphoma (MCL) cells, and to explore its relative mechanisms.

Methods

MTT assay was applied to detect the inhibitory effects of different concentrations of CAL-101. MCL cells were divided into four groups: control group, CAL-101 group, BTZ group, and CAL-101/BTZ group. The expression of PI3K-p110σ, AKT, ERK, p-AKT and p-ERK were detected by Western blot. The apoptosis rates of CAL-101 group, BTZ group, and combination group were detected by flow cytometry. The location changes of nuclear factor kappa-B (NF-κB) of 4 groups was investigated by NF-κB Kit exploring. Western blot was applied to detect the levels of caspase-3 and the phosphorylation of AKT in different groups.

Results

CAL-101 dose- and time-dependently induced reduction in MCL cell viability. CAL-101 combined with BTZ enhanced the reduction in cell viability and apoptosis. Western blot analysis showed that CAL-101 significantly blocked the PI3K/AKT and ERK signaling pathway in MCL cells. The combination therapy contributed to the inactivation of NF-κB and AKT in MCL cell lines. However, cleaved caspase-3 was up-regulated after combined treatment.

Conclusion

Our study showed that PI3K/p110σ is a novel therapeutic target in MCL, and the underlying mechanism could be the blocking of the PI3K/AKT and ERK signaling pathways. These findings provided a basis for clinical evaluation of CAL-101 and a rationale for its application in combination therapy, particularly with BTZ.

ROS-Induced CXCR4 Signaling Regulates Mantle Cell Lymphoma (MCL) Cell Survival and Drug Resistance in the Bone Marrow Microenvironment via Autophagy

PURPOSE

Patients with advanced stages of mantle cell lymphoma (MCL) have a poor prognosis after standard therapies. MCL cells in those patients often spread into tissues other than lymph nodes, such as the bone marrow. Apart from directed migration and homing, there is little understanding of the function of the CXCR4/SDF-1 signaling axis in MCL. In this report, we aim to understand mechanisms of MCL cell survival in the bone marrow.

EXPERIMENTAL DESIGN

For comprehensive analyses of MCL interactions with bone marrow stromal cells, we have generated gene knockout cells using CRISPR-CAS9 system and gene knockdown cells to reveal novel roles of the CXCR4/SDF-1 signaling.

RESULTS

CXCR4 silencing in MCL cells led to a significant reduction in proliferation, cell adhesion to bone marrow stromal cells, and colony formation in PHA-LCM methylcellulose medium, which were reversed upon the addition of SDF-1-neutralizing antibodies. In addition, tracking MCL cell engraftment in vivo revealed that quiescent MCL cells are significantly reduced in the bone marrow upon CXCR4 silencing, indicating that CXCR4/SDF-1 signaling is required for the survival and maintenance of the quiescent MCL cells. Further analysis revealed novel mechanisms of ROS-induced CXCR4/SDF-1 signaling that stimulate autophagy formation in MCL cells for their survival.

CONCLUSIONS

Our data, for the first time, revealed new roles of the CXCR/SDF-1 signaling axis on autophagy formation in MCL, which further promoted their survival within the bone marrow microenvironment. Targeting the CXCR4/SDF-1/autophagy signaling axis may contribute to an enhanced efficacy of current therapies.

Multiple lymphomatous polyposis with diffuse involvement of the gastrointestinal tract. Case report

The gastrointestinal tract is the predominant site of extranodal non-Hodgkin lymphomas. Multiple lynphomatous polyposis is a type of appearance of mantle cell lymphoma. It is characterized by multiple polypoid lesions involving long gastrointestinal tracts and it accounts for only approximately 1-2% of non-Hodgkin lymphomas. A 78 years old patient was admitted to our Department of General Surgery with rectal bleeding, abdominal pain and weight loss. Multiple lymphomatous polyposis was detected by endoscopy. Endoscopic biopsies confirmed the diagnosis of mantle cell lymphoma. The patient was transferred to the Department of Hematology for cycles of chemotherapy.

P110α-mediated constitutive PI3K signaling limits the efficacy of p110δ-selective inhibition in mantle cell lymphoma, particularly with multiple relapse

Phosphoinositide-3 kinase (PI3K) pathway activation contributes to mantle cell lymphoma (MCL) pathogenesis, but early-phase studies of the PI3K p110δ inhibitor GS-1101 have reported inferior responses in MCL compared with other non-Hodgkin lymphomas. Because the relative importance of the class IA PI3K isoforms p110α, p110β, and p110δ in MCL is not clear, we studied expression of these isoforms and assessed their contribution to PI3K signaling in this disease. We found that although p110δ was highly expressed in MCL, p110α showed wide variation and expression increased significantly with relapse. Loss of phosphatase and tensin homolog expression was found in 16% (22/138) of cases, whereas PIK3CA and PIK3R1 mutations were absent. Although p110δ inhibition was sufficient to block B-cell receptor-mediated PI3K activation, combined p110α and p110δ inhibition was necessary to abolish constitutive PI3K activation. In addition, GDC-0941, a predominantly p110α/δ inhibitor, was significantly more active compared with GS-1101 against MCL cell lines and primary samples. We found that a high PIK3CA/PIK3CD ratio identified a subset of primary MCLs resistant to GS-1101 and this ratio increased significantly with relapse. These findings support the use of dual p110α/p110δ inhibitors in MCL and suggest a role for p110α in disease progression.

Relapsed and/or Refractory Mantle Cell Lymphoma: What Role for Temsirolimus?

Mantle Cell Lymphoma (MCL) is associated with a dismal prognosis. Recently, along with the improved understanding of the pathophysiology of this disease, new first line regimens have been established and in addition novel treatment options have entered the clinical arena. In consequence, prognosis of the disease has fortunately improved. We here focus on the rationale, current clinical knowledge and future concepts of Temsirolimus, an inhibitor of mTOR, in the treatment of MCL. At this time this drug has been shown to be effective as single agent for relapsed disease and early combination data show promising results. In addition, with a brief outline of other treatment options, we aim to guide at which place in the current treatment algorithms Temsirolimus can be integrated into the treatment of MCL patients.

Endoscopic findings in mantle cell lymphoma with gastrointestinal tract involvement

BACKGROUND AND AIMS

Mantle cell lymphoma (MCL) of the gastrointestinal (GI) tract is a rare disease with a poor prognosis. The aim of this study was to determine clinical and endoscopic characteristics of patients with GI MCL.

METHODS

Clinical features of 19 patients with GI MCL were reviewed along with the endoscopic findings on 27 anatomical lesions.

RESULTS

The initial presenting symptoms were abdominal pain (n = 7, 36.8%), GI tract bleeding (n = 5, 26.3%), dyspnea (n = 2, 10.5%), indigestion (n = 1, 5.3%), diarrhea (n = 1, 5.3%), cervical lymphadenopathy (n = 1, 5.3%), tonsilar mass (n = 1, 5.3%), and no symptoms (n = 1, 5.3%). On endoscopy, in 19 patients with 27 lesions, the anatomic locations of the lesions were: stomach, n = 2 (10.5%); stomach and colon, n = 7 (36.8%); terminal ileum and colon, n = 1 (5.3%); colon, n = 9 (47.4%). There was 1 fungating case (3.7%), 4 ulcerative cases (14.8%), 9 infiltrative cases (33.3%), and 13 polypoid cases (48.1%).

CONCLUSIONS

The endoscopic findings in GI MCL are variable, with common presenting manifestations of abdominal pain and GI bleeding.

Cancer Tissue Engineering: A Novel 3D Polystyrene Scaffold for In Vitro Isolation and Amplification of Lymphoma Cancer Cells from Heterogeneous Cell Mixtures

Isolation and amplification of primary lymphoma cells in vitro setting is technically and biologically challenging task. To optimize culture environment and mimic in vivo conditions, lymphoma cell lines were used as a test case and were grown in 3-dimension (3D) using a novel 3D tissue culture polystyrene scaffold with neonatal stromal cells to represent a lymphoma microenvironment. In this model, the cell proliferation was enhanced more than 200-fold or 20,000% neoplastic surplus in 7 days when less than 1% lymphoma cells were cocultured with 100-fold excess of neonatal stroma cells, representing 3.2-fold higher proliferative rate than 2D coculture model. The lymphoma cells grew and aggregated to form clusters during 3D coculture and did not maintained the parental phenotype to grow in single-cell suspension. The cluster size was over 5-fold bigger in the 3D coculture by day 4 than 2D coculture system and contained less than 0.00001% of neonatal fibroblast trace. This preliminary data indicate that novel 3D scaffold geometry and coculturing environment can be customized to amplify primary cancer cells from blood or tissues related to hematological cancer and subsequently used for personalized drug screening procedures.

Temsirolimus for the treatment of mantle cell lymphoma

Although recent progress has been made in the treatment of mantle cell lymphoma (MCL) the majority of patients experience relapse and ultimately die of their disease. The translocation t(11;14) is a prerequisite for the diagnosis of MCL and results in overexpression of cyclin D1. Its protein translation is controlled by mTOR, a key element of the PI3K/Akt pathway, and mTOR constitutes an attractive therapeutic target. Temsirolimus, a specific inhibitor of mTOR, has been evaluated in two Phase II trials in patients with relapsed MCL, and promising response rates up to 40% were found. Subsequently, a randomized Phase III trial was initiated, in which superiority in remission induction and progression-free survival could be demonstrated for a regimen of temsirolimus 175 mg for 3 weeks, followed by a 75-mg weekly application in comparison with established agents. This adds temsirolimus to the therapeutic armamentarium for the treatment of MCL. Further developments target combination therapy in MCL and other lymphoid neoplasms.

Mantle cell lymphoma: state-of-the-art management and future perspective

Mantle cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin lymphomas (NHL) characterized in almost all cases by the chromosomal translocation t(11;14)(q13;q32) and nuclear cyclin D1 overexpression. Most patients present with advanced stage disease, often with extranodal dissemination, and typically pursue an aggressive clinical course. Recent improvement has been achieved by the successful introduction of monoclonal antibodies and dose-intensified approaches including autologous stem cell transplantation strategies. However, with the exception of allogeneic hematopoietic stem cell transplantation, current treatment approaches are not curative and the corresponding survival curve is characterized by a relatively steep and continuous decline, with a median survival of about 4 years and <15% long-term survivors. Despite its rarity, MCL is of particular clinical and scientific interest by providing a paradigm for neoplasms with dysregulated control of cell cycle machinery and impaired apoptotic pathways. Recently gained insights into underlying pathobiology unravel numerous promising molecular targeting strategies, however their introduction into clinical practice and current treatment algorithms remains a challenge. This article will provide relevant information for decision making in clinical practice and give a perspective on upcoming management strategies.

Temsirolimus in mantle cell lymphoma and other non-Hodgkin lymphoma subtypes

Temsirolimus, an inhibitor of mammalian target of rapamycin (mTOR), has anti-tumor activity in patients with relapsed or refractory mantle cell lymphoma (MCL) and other mature lymphoid neoplasms. mTOR is an intracellular kinase that controls the mRNA translation of many proteins (eg, cyclin D1) that can act as oncogenes and contribute to lymphomagenesis. Characterized by overexpression of cyclin D1, MCL was identified as a disease that might be susceptible to mTOR inhibition. When single-agent temsirolimus was explored in two phase II studies for treatment of patients with relapsed or refractory MCL, it demonstrated anti-tumor activity, with overall response rates of 38% and 41%. Subsequently, a three-arm, randomized phase III trial was conducted to compare two dosing regimens of temsirolimus with investigator's choice of therapy for heavily pretreated patients with relapsed or refractory MCL (N = 162; randomized 1:1:1). Once-weekly intravenous temsirolimus 175 mg for 3 weeks followed by 75 mg once weekly (175/75) significantly improved progression-free survival (hazard ratio = 0.44; P = .0009) versus investigator's choice therapy. Median progression-free survival durations were 4.8 and 1.9 months, respectively. The objective response rates were 22% in the 175/75 group and 2% in the investigator's choice group (P = .0019). For patients receiving temsirolimus, the most frequent grade 3 or 4 adverse events were thrombocytopenia, anemia, neutropenia, and asthenia. The results of this trial established a recommended clinical dose for temsirolimus monotherapy in patients with relapsed or refractory MCL and validated the importance of mTOR in the pathogenesis of advanced MCL. Objective responses also have been reported for other mature B-cell neoplasms (eg, diffuse large B-cell lymphoma or follicular lymphoma) in the phase II setting. Temsirolimus as monotherapy or in combination with other active agents warrants further investigation for treatment of MCL and other non-Hodgkin lymphomas.

How I treat mantle cell lymphoma

Mantle cell lymphoma is included in the World Health Organization classification as distinct lymphoma subtype characterized by the t(11;14)(q13;q32) translocation, which results in overexpression of Cyclin D1. The clinical presentation often includes extranodal involvement, particularly of the bone marrow and gut. The prognosis of patients with mantle cell lymphoma (median overall survival, 3-5 years) is poorest among B-cell lymphoma patients, even though a prospectively difficult to identify subgroup can survive for years with little or no treatment. Conventional chemotherapy is not curative but obtains frequent remissions (60%-90%) which are usually shorter (1-2 years) compared with other lymphoma entities. Very intensive regimens, including autologous and allogeneic stem cell transplantation, seem required to improve the outcome, but with the median age of diagnosis being 60 years or more, such approaches are feasible only in a limited proportion of patients. The possibility of treating patients based on prognostic factors needs to be investigated prospectively.