Kevin David

Multicenter Analysis of 80 Solid Organ Transplantation Recipients With Post-Transplantation Lymphoproliferative Disease: Outcomes and Prognostic Factors in the Modern Era

PURPOSE Adult post-transplantation lymphoproliferative disease (PTLD) has a reported 3-year overall survival (OS) of 35% to 40%. The impact of rituximab on the outcome of PTLD is not well defined. METHODS We examined the clinical features and outcomes among a large cohort of solid organ transplantation (SOT) -related patients with PTLD who were recently treated at four Chicago institutions (from January 1998 to January 2008). Results Eighty patients with PTLD were identified who had a median SOT-to-PTLD time of 48 months (range, 1 to 216 months). All patients had reduction of immunosuppression as part of initial therapy, whereas 59 (74%) of 80 patients received concurrent first-line rituximab with or without chemotherapy. During 40-month median follow-up, 3-year progression-free survival (PFS) for all patients was 57%, and the 3-year overall survival (OS) rate was 62%. Patients who received rituximab-based therapy as part of initial treatment had 3-year PFS of 70% and OS 73% compared with 21% (P < .0001) and 33% (P = .0001), respectively, without rituximab. Notably, of all relapses, only 9% (4 of 34 patients) occurred beyond 12 months from PTLD diagnosis. On multivariate regression analysis, three factors were associated with progression and survival: CNS involvement (PFS, 4.70; P = .01; OS, 3.61; P = .04), bone marrow involvement (PFS, 2.95; P = .03; OS, 3.14; P = .03), and hypoalbuminemia (PFS, 2.96; P = .05; OS, 3.64; P = .04). Furthermore, a survival model by multivariate CART analysis that was based on number of adverse factors present (ie, 0, 1, > or = 2) was formed: 3-year PFS rates were 84%, 66%, 7%, respectively, and 3-year OS rates were 93%, 68%, 11%, respectively (P < .0001). CONCLUSION This large, multicenter, retrospective analysis suggests significantly improved PFS and OS associated with early rituximab-based treatment in PTLD. In addition, clinical factors at diagnosis identified patients with markedly divergent outcomes.

PCI-24781 Induces Caspase and Reactive Oxygen Species–Dependent Apoptosis Through NF-κB Mechanisms and Is Synergistic with Bortezomib in Lymphoma Cells

Purpose: We investigated the cytotoxicity and mechanisms of cell death of the broad-spectrum histone deacetylase (HDAC) inhibitor PCI-24781, alone and combined with bortezomib in Hodgkin lymphoma and non-Hodgkin lymphoma cell lines and primary lymphoproliferative (CLL/SLL) cells. Experimental Design: Apoptosis, mitochondrial membrane potential, cell cycle analysis, and reactive oxygen species (ROS) were measured by flow cytometry, whereas caspase activation was determined by Western blot. Nuclear factor κB (NF-κB)-related mRNAs were quantified by reverse transcription-PCR, NF-κB–related proteins by Western blotting, and NF-κB DNA-binding activity by electromobility shift assay. Finally, gene expression profiling was analyzed. Results: PCI-24781 induced concentration-dependent apoptosis that was associated with prominent G0/G1 arrest, decreased S-phase, increased p21 protein, and increased ROS in Hodgkin lymphoma and non-Hodgkin lymphoma cell lines. Dose-dependent apoptosis with PCI-24781 was also seen among primary CLL/SLL cells. PCI-24781–induced apoptosis was shown to be ROS- and caspase-dependent. Combined PCI-24781/bortezomib treatment resulted in strong synergistic apoptosis in all non-Hodgkin lymphoma lines (combination indices, 0.19-0.6) and was additive in Hodgkin lymphoma and primary CLL/SLL cells. Further, PCI-24781/bortezomib resulted in increased caspase cleavage, mitochondrial depolarization, and histone acetylation compared with either agent alone. Gene expression profiling showed that PCI-24781 alone significantly down-regulated several antioxidant genes, proteasome components, and NF-κB pathway genes, effects that were enhanced further with bortezomib. Reverse transcription-PCR confirmed down-regulation of NF-κB1 (p105), c-Myc, and IκB-kinase subunits, where NF-κB DNA binding activity was decreased. Conclusion: We show that PCI-24781 results in increased ROS and NF-κB inhibition, leading to caspase-dependent apoptosis. We also show that bortezomib is synergistic with PCI-24781. This combination or PCI-24781 alone has potential therapeutic value in lymphoma.

Type I interferon (IFN)-dependent activation of Mnk1 and its role in the generation of growth inhibitory responses

We provide evidence for the existence of an IFN-regulated cellular pathway involving the mitogen-activated protein kinase (MAPK)-integrating kinase (Mnk) 1. Our data demonstrate that type I (α, β) IFNs induce phosphorylation/activation of Mnk1, which, in turn, regulates phosphorylation of the eukaryotic initiation factor 4E (eIF4E) on Ser-209. Such Mnk activation depends on upstream engagement of Jak1, and requires downstream activation of the Mek/Erk MAPK pathway. In studies using double Mnk1−/−Mnk2−/− knockout mouse embryonic fibroblasts (MEFs), we found that engagement of Mnk kinases is essential for mRNA translation of the Isg15 and Isg54 genes, suggesting an important role for this pathway in mRNA translation of IFN-stimulated genes (ISGs). Importantly, our data demonstrate that pharmacological inhibition of Mnk kinases or siRNA-mediated knockdown of Mnk1 and Mnk2 results in partial reversal of the suppressive effects of IFNα on normal and leukemic hematopoietic progenitors, establishing a key role for this pathway in the generation of the growth inhibitory effects of type I IFNs. Together, our findings establish that the Mnk/eIF4E kinase pathway is activated in an IFN-inducible manner and plays important roles in mRNA translation for ISGs and generation of IFN-inducible anti-proliferative responses.

Mitochondrial-mediated apoptosis in lymphoma cells by the diterpenoid lactone andrographolide, the active component of Andrographis paniculata.

Purpose: Andrographolide is a diterpenoid lactone isolated from Andrographis paniculata (King of Bitters), an herbal medicine used in Asia. It has been reported to have anti-inflammatory, antihypertensive, antiviral, and immune-stimulant properties. Furthermore, it has been shown to inhibit cancer cell proliferation and induce apoptosis in leukemia and solid tumor cell lines. Experimental Design: We studied the Burkitt p53-mutated Ramos cell line, the mantle cell lymphoma (MCL) line Granta, the follicular lymphoma (FL) cell line HF-1, and the diffuse large B-cell lymphoma (DLBCL) cell line SUDHL4, as well as primary cells from patients with FL, DLBCL, and MCL. Results: We found that andrographolide resulted in dose- and time-dependent cell death as measured by MTT. Andrographolide significantly increased reactive oxygen species (ROS) production in all cell lines. To determine mechanism of cell death, we measured apoptosis by Annexin V/propidium iodide in the presence and absence of the antioxidant N-acetyl-l-cysteine (NAC), the glutathione (GSH)–depleting agent buthionine sulfoxamine (BSO), or caspase inhibitors. We found that apoptosis was greatly enhanced by BSO, blocked by NAC, and accompanied by poly(ADP-ribose) polymerase cleavage and activation of caspase-3, caspase-8, and caspase-9. We measured BAX conformational change and mitochondrial membrane potential, and using mouse embryonic fibroblast (MEF) Bax/Bak double knockouts (MEFBax−/−/Bak−/−), we found that apoptosis was mediated through mitochondrial pathways, but dependent on caspases in both cell lines and patient samples. Conclusions: Andrographolide caused ROS-dependent apoptosis in lymphoma cell lines and in primary tumor samples, which was enhanced by depletion of GSH and inhibited by NAC or the pan-caspase inhibitor Z-VAD-FMK. Further studies of diterpenoid lactones in lymphoma are warranted. Clin Cancer Res; 16(19); 4755–68. ©2010 AACR.

Glutathione depletion enhances arsenic trioxide-induced apoptosis in lymphoma cells through mitochondrial-independent mechanisms

Arsenic trioxide (ATO) is an effective therapeutic agent for acute promyelocytic leukemia (APL) (Evens et al, 2004). In APL, ATO induces differentiation at low concentrations, while inducing apoptosis at higher concentrations (Miller, et al 2002). In addition, ATO-induced apoptosis in APL is mediated through the mitochondrial apoptotic pathway, resulting in part from the production of reactive oxygen species (ROS) such as hydrogen peroxide (Dai, et al 1999, Yi, et al 2002). High intracellular levels of glutathione (GSH) confer resistance to ATO in part through the detoxification of ROS. Compounds that promote ROS and/or deplete protective metabolites such as GSH are able to sensitize tumor cells to oxidative cytolysis. Buthionine sulfoximine (BSO), a selective inhibitor of gamma glutamylcysteine synthetase, is known to effectively deplete cellular GSH (Davison, et al 2003, Gartenhaus, et al 2002). We evaluated herein the cytotoxic activity and cell death pathways induced by ATO alone and combined with BSO in non-Hodgkin’s lymphoma (NHL) cell lines and primary lymphoproliferative cells.

Relapsed and Refractory Hodgkin Lymphoma: Transplantation Strategies and Novel Therapeutic Options

Opinion statementMany patients with Hodgkin lymphoma are cured with initial therapy, although a portion of patients will experience primary induction failure or disease relapse. Pathologic confirmation of refractory or relapsed Hodgkin lymphoma is important. Following two to four cycles of non-cross-resistant salvage chemotherapy, the standard of care is high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (HSCT), which is associated with long-term event-free survival rates of 45–68%. Of note, survival rates for studies integrating total lymphoid irradiation into the autologous HSCT-conditioning regimen are among the highest reported for relapsed/refractory Hodgkin lymphoma. Further treatment options are available for patients not fit to proceed to HSCT, for relapsed disease after autologous HSCT, and for ‹high-risk’ Hodgkin lymphoma including chemotherapy-resistant disease. Allogeneic HSCT is a valid treatment option, as a graft-vs.-Hodgkin-lymphoma effect has been demonstrated. In addition, novel targeted treatments are being investigated such as receptor-specific antibodies, radiolabeled antibodies, antiapoptotic agents including inhibitors of the nuclear factor-κB complex or X-linked inhibitor of apoptosis proteins, transcription pathway modulators such as histone deacetylase and mTOR inhibitors, and Epstein-Barr virus-directed therapy. Continued translational and collaborative prospective clinical research efforts are needed in order to continue to increase the survival rates for Hodgkin lymphoma and to lessen the toxicities associated with lymphoma-related therapy.

Burkitt Lymphoma and Leukemia

Burkitt lymphoma and Burkitt leukemia are highly aggressive B-cell malignancies characterized genetically by constitutive activation of the c-myc oncogene and clinically by a rapid growth phase often with extranodal presentation including frequent central nervous system (CNS) involvement. The aggressiveness of this malignancy, with a tumor doubling time of 24–48 h, necessitates prompt initiation of therapy. The British surgeon Denis Burkitt first described this disease entity in 1958 after observing a clustering of cases of children with jaw tumors spanning central East Africa [1]. He found that while surgical resection was not particularly effective against the disease, chemotherapy could treat, and in some cases, cure these neoplasms. Survival rates improved significantly first in children through the use of shorter duration, dose-intensive systemic chemotherapy protocols with early prophylaxis/treatment of the CNS. Similar therapeutic regimens have been adapted in adults using intensive multi-agent chemotherapy plans, which have resulted in similarly improved long-term survival rates.