Precision medicine and lymphoma

POLE2 knockdown suppresses lymphoma progression via downregulating Wnt/β-catenin signaling pathway

Lymphoma is the most common malignant tumor arising from immune system. Recently, DNA polymerase epsilon subunit 2 (POLE2) was identified to be a tumor promotor in a variety of malignant tumors. However, the biological role of POLE2 in lymphoma is still largely unclear. In our present study, the expression patterns of POLE2 in lymphoma tissues were identified by immunohistochemistry (IHC) staining of human tissue microarray. Cell viability was determined by CCK-8 assay. Cell apoptosis and cycle distribution were evaluated by Annexin V and PI staining, respectively. Cell migration was analyzed by transwell assay. Tumor growth in vivo was observed by a xenograft model of mice. The potential signaling was explored by human phospho-kinase array and immunoblotting. POLE2 was significantly upregulated in human lymphoma tissues and cells. POLE2 knockdown attenuated the proliferation, migration capabilities of lymphoma cells, as well as induced cell apoptosis and cycle arrest. Moreover, POLE2 depletion impaired the tumor growth in mice. Furthermore, POLE2 knockdown apparently inhibited the activation of β-Catenin and downregulated the expression of Wnt/β-Catenin signaling-related proteins. POLE2 knockdown suppressed the proliferation and migration of lymphoma cells by inhibiting Wnt/β-Catenin signaling pathway. POLE2 may serve as a novel therapeutic target for lymphoma.

Inhibitory Effects of Periplocin on Lymphoma Cells: A Network Pharmacology Approach and Experimental Validation

Purpose

Lymphoma is considered to be one of the most pressing health problems worldwide owing to its high incidence and mortality. Previous studies have shown that periplocin, a naturally occurring compound, inhibits growth and induces apoptosis in several cancers. However, the effects of periplocin on lymphoma and the underlying mechanisms of action remain unclear.

Methods

The PharmMapper database was used to predict the potential targets of periplocin. The GeneCard database was used to identify lymphoma-related genes. A few intersecting genes were obtained, and the protein-protein interaction network was visualized using STRING Gene ontology analysis. Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed using R project. MTS assay, flow cytometry, real-time quantitative polymerase chain reaction (qPCR), and Western blotting were used to verify whether periplocin possesses anti-lymphoma activity.

Results

A total of 216 intersecting genes were identified. Numerous cancer-related signaling pathways were visualized using Cytoscape software, with the PI3K-Akt signaling pathway being the highest-ranked pathway related to cell proliferation, apoptosis, and cell cycle progression. HuT 78 and Jurkat cell lines were used to verify the predictions. Periplocin significantly inhibited their proliferation in a dose- and time-dependent manner, but had no effect on the viability of peripheral blood lymphocytes. Flow cytometry revealed that treatment with periplocin increased the apoptotic rate and ratio of HuT 78 and Jurkat cells in the G2/M phase. CDK1 and cyclin B1 complex formation is a key gatekeeper to mitotic division in the G2/M phase. Western blot analysis revealed that periplocin significantly decreased the protein levels of CDK1 and cyclin B1; however, real-time qPCR revealed no effect on gene expression.

Conclusion

Periplocin showed anti-tumor effects in lymphoma cells through multiple targets and signaling pathways, and could be a novel therapeutic agent for the treatment of lymphoma.

Germinal Center Cells Turning to the Dark Side: Neoplasms of B Cells, Follicular Helper T Cells, and Follicular Dendritic Cells

Gaining knowledge of the neoplastic side of the three main cells—B cells, Follicular Helper T (Tfh) cells, and follicular dendritic cells (FDCs) —involved in the germinal center (GC) reaction can shed light toward further understanding the microuniverse that is the GC, opening the possibility of better treatments. This paper gives a review of the more complex underlying mechanisms involved in the malignant transformations that take place in the GC. Whilst our understanding of the biology of the GC-related B cell lymphomas has increased—this is not reviewed in detail here—the dark side involving neoplasms of Tfh cells and FDCs are poorly studied, in great part, due to their low incidence. The aggressive behavior of Tfh lymphomas and the metastatic potential of FDCs sarcomas make them clinically relevant, merit further attention and are the main focus of this review. Tfh cells and FDCs malignancies can often be misdiagnosed. The better understanding of these entities linked to their molecular and genetic characterization will lead to prediction of high-risk patients, better diagnosis, prognosis, and treatments based on molecular profiles.

Targeted reduction of cholesterol uptake in cholesterol-addicted lymphoma cells blocks turnover of oxidized lipids to cause ferroptosis

Normal human cells can either synthesize cholesterol or take it up from lipoproteins to meet their metabolic requirements. In some malignant cells, de novo cholesterol synthesis genes are transcriptionally silent or mutated, meaning that cholesterol uptake from lipoproteins is required for survival. Recent data suggest that lymphoma cells dependent upon lipoprotein-mediated cholesterol uptake are also subject to ferroptosis, an oxygen- and iron-dependent cell death mechanism triggered by accumulation of oxidized lipids in cell membranes unless the lipid hydroperoxidase, glutathione peroxidase 4 (GPX4), reduces these toxic lipid species. To study mechanisms linking cholesterol uptake with ferroptosis and determine the potential role of the high-density lipoprotein (HDL) receptor as a target for cholesterol depleting therapy, we treated lymphoma cell lines known to be sensitive to the reduction of cholesterol uptake with HDL-like nanoparticles (HDL NPs). HDL NPs are a cholesterol-poor ligand that binds to the receptor for cholesterol-rich HDLs, scavenger receptor type B1 (SCARB1). Our data reveal that HDL NP treatment activates a compensatory metabolic response in treated cells toward increased de novo cholesterol synthesis, which is accompanied by nearly complete reduction in expression of GPX4. As a result, oxidized membrane lipids accumulate, leading to cell death through a mechanism consistent with ferroptosis. We obtained similar results in vivo after systemic administration of HDL NPs in mouse lymphoma xenografts and in primary samples obtained from patients with lymphoma. In summary, targeting SCARB1 with HDL NPs in cholesterol uptake-addicted lymphoma cells abolishes GPX4, resulting in cancer cell death by a mechanism consistent with ferroptosis.

Cost burden of diffuse large B-cell lymphoma

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma and is a clinically heterogeneous disease. Treatment pathways for DLBCL are diverse and integrate established and novel therapies.Areas covered: We review the cost burden of DLBCL and the cost-effectiveness of DLBCL management including precision and cellular medicine. We utilized Medical Subject Heading (MeSH) terms and keywords to search the National Library of Medicine online MEDLINE database (PubMed) for articles related to cost, cost burden, and cost-of-illness of DLBCL and cost-effectiveness of DLBCL management strategies published in English as of June 2019.Expert commentary: Available and developing DLBCL therapies offer improved outcomes and often curative treatment at considerable financial expense, and the total cost burden for DLBCL management is substantial for patients and the healthcare system. In the era of personalized medicine, CAR T cells and targeted therapies provide exciting avenues for current and future DLBCL care and can further increase treatment cost. Determinations of cost and cost-effectiveness in DLBCL treatment pathways should continue to guide care providers and systems in identifying cost reduction strategies to provide appropriate therapies to the greatest number of patients in treating DLBCL.