Nanoencapsulated rituximab mediates superior cellular immunity against metastatic B-cell lymphoma in a complement competent humanized mouse model

BackgroundDespite the numerous applications of monoclonal antibodies (mAbs) in cancer therapeutics, animal models available to test the therapeutic efficacy of new mAbs are limited. NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice are one of the most highly immunodeficient strains and are universally used as a model for testing cancer-targeting mAbs. However, this strain lacks several factors necessary to fully support antibody-mediated effector functions—including antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and complement-dependent cytotoxicity (CDC)—due to the absence of immune cells as well as a mutation in the Hc gene, which is needed for a functional complement system.MethodsWe have developed a humanized mouse model using a novel NSG strain, NOD.Cg−Hc1Prkdcscid Il2rgtm1Wjl/SzJ (NSG−Hc1), which contains the corrected mutation in the Hc gene to support CDC in addition to other mechanisms endowed by humanization. With this model, we reevaluated the anticancer efficacies of nanoencapsulated rituximab after xenograft of the human Burkitt lymphoma cell line 2F7-BR44.ResultsAs expected, xenografted humanized NSG−Hc1 mice supported superior lymphoma clearance of native rituximab compared with the parental NSG strain. Nanoencapsulated rituximab with CXCL13 conjugation as a targeting ligand for lymphomas further enhanced antilymphoma activity in NSG−Hc1 mice and, more importantly, mediated antilymphoma cellular responses.ConclusionsThese results indicate that NSG−Hc1 mice can serve as a feasible model for both studying antitumor treatment using cancer targeting as well as understanding induction mechanisms of antitumor cellular immune response.

Antiproliferative and proapoptotic effects of Inula viscosa extract on Burkitt lymphoma cell line

Burkitt lymphoma is a very aggressive B-cell non-Hodgkin lymphoma. Although remarkable progress has been made in the therapeutic scenario for patients with Burkitt lymphoma, search and development of new effective anticancer agents to improve patient outcome and minimize toxicity has become an urgent issue. In this study, the antitumoral activity of Inula viscosa, a traditional herb obtained from plants collected on the Asinara Island, Italy, was evaluated in order to explore potential antineoplastic effects of its metabolites on Burkitt lymphoma. Raji human cell line was treated with increasing Inula viscosa extract concentration for cytotoxicity screening and subsequent establishment of cell cycle arrest and apoptosis. Moreover, gene expression profiles were performed to identify molecular mechanisms involved in the anticancer activities of this medical plant. The Inula viscosa extract exhibited powerful antiproliferative and cytotoxic activities on Raji cell line, showing a dose- and time-dependent decrease in cell viability, obtained by cell cycle arrest in the G2/M phase and an increase in cell apoptosis. The treatment with Inula viscosa caused downregulation of genes involved in cell cycle and proliferation (c-MYC, CCND1) and inhibition of cell apoptosis (BCL2, BCL2L1, BCL11A). The Inula viscosa extract causes strong anticancer effects on Burkitt lymphoma cell line. The molecular mechanisms underlying such antineoplastic activity are based on targeting and downregulation of genes involved in cell cycle and apoptosis. Our data suggest that Inula viscosa natural metabolites should be further exploited as potential antineoplastic agents against Burkitt lymphoma.

Lenti-shRNA-mediated FAM54A knockdown suppresses the proliferation and induces apoptosis of human Burkitt lymphoma cells

Background Burkitt lymphoma is a kind of non-Hodgkin B-cell-derived malignancy, derived from germinal center B cells. FAM54A has been proved to be involved in various physiological and pathological processes of cancers, but the biological function of FAM54A in Burkitt lymphoma remains unclear. Thus, the aim of our research was to elucidate the roles of FAM54A in proliferation, apoptosis and cell cycle of Burkitt lymphoma.Methods Burkitt lymphoma cell line (Namalwa) was chosen to perform the following experiments. FAM54A-shRNA and negative control-shRNA lentivirus that were synthesized, respectively by Qiagen were used to transfect targeted cells in order to knockdown FAM54A or as negative control. Then, cell proliferation, cell cycle and cell apoptosis were detected by using MTS assay, propidium iodide staining and Annexin V-APC staining, respectively.Results Our results showed that high expression of FAM54A protein was found in Namalwa cell line. Furthermore, MTS analysis exhibited that knockdown of FAM54A obviously inhibited cell proliferation in Namalwa cells. What’s more, cell cycle analysis showed that knockdown of FAM54A induced Namalwa cell apoptosis and arrested cell cycle in G2/M phase.Conclusions These findings suggest that FAM54A is essential for Namalwa cell proliferation and may be a potential therapeutic target for the treatment of Burkitt lymphoma.

Cytotoxic Effect of Icaritin and Its Mechanisms in Inducing Apoptosis in Human Burkitt Lymphoma Cell Line

Icaritin (ICT), a hydrolytic product of icariin fromEpimedium genus, exhibits antitumor activities in several human solid-tumor and myeloid leukemia cells with extensive influence on various cell signal molecules, such as MAPKs being involved in cell proliferation and Bcl-2 participating in cell apoptosis. However, the effect of icaritin on Burkitt Lymphoma has not been elucidated. In the present study, we first screened the potential effect of icaritin on Burkitt lymphoma Raji and P3HR-1 cell lines and found that icaritin showed cytotoxicity in both cell lines. We further found that icaritin could significantly inhibit Raji cells proliferation with S-phase arrest of cell cycle and induced cell apoptosis accompanied by activation of caspase-8 and caspase-9 and cleavage of PARP. We also observed that icaritin was able to decrease Bcl-2 levels, thus shifting the Bcl-2/Bax ratio, and it could obviously reduce c-Myc, a specific molecular target in Burkitt lymphoma. Our findings demonstrated that icaritin showed cytotoxicity, inhibited cell growth, caused S arrest, and induced apoptosis in Burkitt lymphoma cells and provided a rationale for the further evaluation of icaritin for Burkitt lymphoma therapy.