Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma of which at least a subset arises from antigen-experienced B cells. However, what role antigen stimulation plays in its pathogenesis ...remains ill defined. The genetic hallmark is the chromosomal translocation t(11;14) resulting in aberrant expression of cyclin D1. Secondary genetic events increase the oncogenic potential of cyclin D1 and frequently inactivate DNA damage response pathways. In combination these changes drive cell-cycle progression and give rise to pronounced genetic instability. Several signaling pathways contribute to MCL pathogenesis, including the often constitutively activated PI3K/AKT/mTOR pathway, which promotes tumor proliferation and survival. WNT, Hedgehog, and NF-κB pathways also appear to be important. Although MCL typically responds to frontline chemotherapy, it remains incurable with standard approaches. Proteasome inhibitors (bortezomib), mTOR inhibitors (temsirolimus), and immunomodulatory drugs (lenalidomide) have recently been added to the treatment options in MCL. The molecular basis for the antitumor activity of these agents is an area of intense study that hopefully will lead to further improvements in the near future. Given its unique biology, relative rarity, and the difficulty in achieving long-lasting remissions with conventional approaches, patients with MCL should be encouraged to participate in clinical trials.
Dialkylbiphenylphosphane–AuI complexes exhibit only weak metal–arene interactions with the covering arene ring. However, the contacts in isoleptic AgI and CuI complexes are shorter than the limiting ...values of 3.03 Å (AgI) and 2.83 Å (CuI). Strong metal–arene interactions were also found in the two AgI aquo complexes and in two acetonitrileCuI complexes with dialkylbiphenylphosphane ligands. Arene–AgI complexes with these bulky phosphane ligands show the strongest AgIarene bonds known.
Weakness and strength: Whereas AuI interacts weakly with the covering arene ring in complexes with dialkylbiphenylphosphane ligands, strong interactions have been found in AgI and CuI complexes. Dialkylbiphenylphosphane arene–AgI complexes, such as the example illustrated (Cy=cyclohexyl), have the strongest AgIarene bonds known.
Cardiovascular diseases are the leading cause of death globally and more than four out of five cases are due to ischemic events. Cardiac fibroblasts (CF) contribute to normal heart development and ...function, and produce the post‐ischemic scar. Here, we characterize the biochemical and functional aspects related to CF endurance to ischemia‐like conditions. Expression data mining showed that cultured human CF (HCF) express more BCL2 than pulmonary and dermal fibroblasts. In addition, gene set enrichment analysis showed overrepresentation of genes involved in the response to hypoxia and oxidative stress, respiration and Janus kinase (JAK)/Signal transducer and Activator of Transcription (STAT) signaling pathways in HCF. BCL2 sustained survival and proliferation of cultured rat CF, which also had higher respiration capacity and reactive oxygen species (ROS) production than pulmonary and dermal fibroblasts. This was associated with higher expression of the electron transport chain (ETC) and antioxidant enzymes. CF had high phosphorylation of JAK2 and its effectors STAT3 and STAT5, and their inhibition reduced viability and respiration, impaired ROS control and reduced the expression of BCL2, ETC complexes and antioxidant enzymes. Together, our results identify molecular and biochemical mechanisms conferring survival advantage to experimental ischemia in CF and show their control by the JAK2/STAT signaling pathway. The presented data point to potential targets for the regulation of cardiac fibrosis and also open the possibility of a general mechanism by which somatic cells required to acutely respond to ischemia are constitutively adapted to survive it.
Cardiovascular disease is a leading cause of death worldwide. Cardiac fibroblasts play a key role in remodeling of the extracellular matrix after ischemic damage and must endure low availability of oxygen, nutrients and trophic factors in order to secrete a fibrotic scar after myocardial ischemia. Using in vitro models, Daniel Sanchez and co‐authors show that, compared to pulmonary and dermal fibroblasts, cardiac fibroblasts display high oxygen consumption capacity, high production of reactive oxygen species (ROS), improved ROS control and an overall survival advantage in ischemia‐like conditions. These attributes are governed by high constitutive activation of the JAK2/STAT pathway.
Follicular lymphoma (FL) is a paradigm of tumors that require the interaction between tumor and microenvironment cells to foster their development from initial steps to progression. Recent ...large‐scale genome studies have uncovered multiple genetic alterations of FL that influence the microenvironment in two main directions, promoting tumor cell survival and proliferation and facilitating their evasion from immune antitumor signals. Understanding the crosstalk between tumor B‐cells and the microenvironment will facilitate the identification of vulnerabilities that may offer novel targets for treatment of the patients. This review highlights recent findings showing the effect of common genetic mutations modulating the cell composition of the tumor microenvironment and the novel therapeutic perspectives to target these interactions.
Genetically modifying autologous T cells to express an anti-CD19 chimeric antigen receptor (CAR) has shown impressive response rates for the treatment of CD19+ B cell malignancies in several clinical ...trials (CTs). Making this treatment available to our patients prompted us to develop a novel CART19 based on our own anti-CD19 antibody (A3B1), followed by CD8 hinge and transmembrane region, 4-1BB- and CD3z-signaling domains. We show that A3B1 CAR T cells are highly cytotoxic and specific against CD19+ cells
, inducing secretion of pro-inflammatory cytokines and CAR T cell proliferation.
, A3B1 CAR T cells are able to fully control disease progression in an NOD.Cg-
/SzJ (NSG) xenograph B-ALL mouse model. Based on the pre-clinical data, we conclude that our CART19 is clearly functional against CD19+ cells, to a level similar to other CAR19s currently being used in the clinic. Concurrently, we describe the implementation of our CAR T cell production system, using lentiviral vector and CliniMACS Prodigy, within a medium-sized academic institution. The results of the validation phase show our system is robust and reproducible, while maintaining a low cost that is affordable for academic institutions. Our model can serve as a paradigm for similar institutions, and it may help to make CAR T cell treatment available to all patients.
Summary
Relapsed or refractory diffuse large B‐cell lymphoma (DLBCL) cases have a poor outcome. Here we analysed clinico‐biological features in 373 DLBCL patients homogeneously treated with ...rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R‐CHOP), in order to identify variables associated with early failure to treatment (EF), defined as primary refractoriness or relapse within 12 months from diagnosis. In addition to clinical features, mutational status of 106 genes was studied by targeted next‐generation sequencing in 111 cases, copy number alterations in 87, and gene expression profile (GEP) in 39. Ninety‐seven cases (26%) were identified as EF and showed significantly shorter overall survival (OS). Patients with B symptoms, advanced stage, high levels of serum lactate dehydrogenase (LDH) or β2‐microglobulin, low lymphocyte/monocyte ratio and higher Revised International Prognostic Index (R‐IPI) scores, as well as those with BCL2 rearrangements more frequently showed EF, with R‐IPI being the most important in logistic regression. Mutations in NOTCH2, gains in 5p15·33 (TERT), 12q13 (CDK2), 12q14·1 (CDK4) and 12q15 (MDM2) showed predictive importance for EF independently from R‐IPI. GEP studies showed that EF cases were significantly enriched in sets related to cell cycle regulation and inflammatory response, while cases in response showed over‐representation of gene sets related to extra‐cellular matrix and tumour microenvironment.
Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma resistant to conventional chemotherapy. The Bcl-2 pathway is deregulated in these tumors and may represent an interesting target for new ...therapeutic strategies. The new small-molecule pan–Bcl-2 inhibitor GX15-070 mimics BH3-only proteins by binding to multiple antiapoptotic Bcl-2 members. Here we show that GX15-070 induced apoptosis in vitro in MCL cell lines and primary cells from patients with MCL by releasing Bak from Mcl-1 and Bcl-XL at short incubation times and low micromolar doses. GX15-070 was effective in cells bearing defective DNA damage-sensor genes or cell-cycle regulators, inducing Bax and Bak conformational changes, mitochondrial depolarization, phosphatidylserine exposure, and caspase-3 activation. Furthermore, GX15-070 synergized with bortezomib, sensitizing MCL cells to low doses of this proteasome inhibitor, by neutralizing bortezomib-induced Mcl-1 accumulation and cooperating with Noxa to induce Bak displacement from this protein. These events led to an increased activation of the mitochondrial apoptotic pathway. Importantly, GX15-070 alone or in combination with bortezomib showed no significant cytotoxic effect in peripheral blood mononuclear cells from healthy donors. All these findings suggest that GX15-070 alone or in combination with bortezomib represents a new attractive therapeutic approach for MCL treatment.
A facile synthesis of chiral cyclic alkyl aminocarbene–gold(I) complexes from gold‐free 1,7‐enyne substrates was developed. The novel cyclization–rearrangement reaction sequence is triggered by the ...addition of (Me2S)AuCl to different 1,7‐enynes and leads to structurally unique carbene–gold(I) complexes in high yields. These novel complexes are catalytically active and inhibit the proliferation of different human cancer cell lines.
Golden opportunities: A cyclization–rearrangement cascade of different 1,7‐enynes triggered by the addition of (Me2S)AuCl provides facile access to structurally unique chiral cyclic alkyl aminocarbene–gold(I) complexes in high yields. These novel complexes are catalytically active and display biologic activity against cancer cell lines.
The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has been shown to be highly effective in patients with chronic lymphocytic leukemia (CLL) and is approved for CLL treatment. Unfortunately, ...resistance and intolerance to ibrutinib has been observed in several studies, opening the door for more specific BTK inhibitors. CC‐292 (spebrutinib) is a BTK inhibitor with increased specificity for BTK and less inhibition of other kinases. Our in vitro studies showed that CC‐292 potently inhibited B‐cell receptor signaling, activation, proliferation and chemotaxis of CLL cells. In in vivo studies using the adoptive transfer TCL1 mouse model of CLL, CC‐292 reduced tumor load and normalized tumor‐associated expansion of T cells and monocytes, while not affecting T cell function. Importantly, the combination of CC‐292 and bendamustine impaired CLL cell proliferation in vivo and enhanced the control of CLL progression. Our results demonstrate that CC‐292 is a specific BTK inhibitor with promising performance in combination with bendamustine in CLL. Further clinical trials are warranted to investigate the therapeutic efficacy of this combination regimen.
What's new?
B‐cell receptor (BCR) signaling plays a pivotal role in chronic lymphocytic leukemia (CLL). BTK inhibitor ibrutinib has been shown to be highly effective in patients, but resistance and intolerance have also been observed. Here, the authors demonstrate that the more specific CC‐292 disrupts BCR signaling and inhibits tumor cell activation, proliferation, and chemotaxis in vitro. In mice, CC‐292 reduces tumor load and normalizes tumor‐associated expansion of T cells and monocytes while not affecting T cell function. Combination of CC‐292 and bendamustine impairs CLL cell proliferation and normalizes immune cell composition, which overcomes microenvironment‐mediated chemoresistance and enhances control of CLL progression.