Silencing PEX26 as an unconventional mode to kill drug-resistant cancer cells and forestall drug resistance.

Promoting the macroautophagy/autophagy-mediated degradation of specific proteins and organelles can potentially be utilized to induce apoptosis in cancer cells or sensitize tumor cells to therapy. To examine this concept, we enriched for autophagosomes from histone deacetylase inhibitor (HDACi)-sensitive U937 lymphoma cells and isogenic HDACi-resistant cells. Mass spectrometry on autophagosome-enriched fractions revealed that HDACi-resistant cells undergo elevated pexophagy, or autophagy of the peroxisome, an organelle that supports tumor growth. To disturb peroxisome homeostasis, we enhanced pexophagy in HDACi-resistant cells via genetic silencing of peroxisome exportomer complex components (PEX1, PEX6, or PEX26). This consequently sensitized resistant cells to HDACi-mediated apoptosis, which was rescued by inhibiting ATM/ataxia-telangiectasia mutated (ATM serine/threonine kinase), a mediator of pexophagy. We subsequently engineered melanoma cells to stably repress PEX26 using CRISPR interference (CRISPRi). Melanoma cells with repressed PEX26 expression showed evidence of both increased pexophagy and peroxisomal matrix protein import defects versus single guide scrambled (sgSCR) controls. In vivo studies showed that sgPEX26 melanoma xenografts recurred less compared to sgSCR xenografts, following the development of resistance to mitogen-activated protein kinase (MAPK)-targeted therapy. Finally, prognostic analysis of publicly available datasets showed that low expression levels of PEX26, PEX6 and MTOR, were significantly associated with prolonged patient survival in lymphoma, lung cancer and melanoma cohorts. Our work highlighted that drugs designed to disrupt peroxisome homeostasis may serve as unconventional therapies to combat therapy resistance in cancer.Abbreviations: ABCD3/PMP70: ATP binding cassette subfamily D member 3; ACOX1: acyl-CoA oxidase 1; AP: autophagosome; COX: cytochrome c oxidase; CQ: chloroquine; CRISPRi: clustered regularly interspaced short palindromic repeats interference; DLBCL: diffuse large B-cell lymphoma; GO: gene ontology; dCas9: Cas9 endonuclease dead, or dead Cas9; HDACi: histone deacetylase inhibitors; IHC: Immunohistochemistry; LAMP2: lysosomal associated membrane protein 2; LCFAs: long-chain fatty acids; LFQ-MS: label-free quantitation mass spectrometry; LPC: lysophoshatidylcholine; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MTOR: mechanistic target of rapamycin kinase; PBD: peroxisome biogenesis disorders; PTS1: peroxisomal targeting signal 1; ROS: reactive oxygen species; sgRNA: single guide RNA; VLCFAs: very-long chain fatty acids; Vor: vorinostat; WO: wash-off.

The MNK1/2-eIF4E Axis Supports Immune Suppression and Metastasis in Postpartum Breast Cancer.

Breast cancer diagnosed within 10 years following childbirth is defined as postpartum breast cancer (PPBC) and is highly metastatic. Interactions between immune cells and other stromal cells within the involuting mammary gland are fundamental in facilitating an aggressive tumor phenotype. The MNK1/2-eIF4E axis promotes translation of prometastatic mRNAs in tumor cells, but its role in modulating the function of nontumor cells in the PPBC microenvironment has not been explored. Here, we used a combination of in vivo PPBC models and in vitro assays to study the effects of inactivation of the MNK1/2-eIF4E axis on the protumor function of select cells of the tumor microenvironment. PPBC mice deficient for phospho-eIF4E (eIF4ES209A) were protected against lung metastasis and exhibited differences in the tumor and lung immune microenvironment compared with wild-type mice. Moreover, the expression of fibroblast-derived IL33, an alarmin known to induce invasion, was repressed upon MNK1/2-eIF4E axis inhibition. Imaging mass cytometry on PPBC and non-PPBC patient samples indicated that human PPBC contains phospho-eIF4E high-expressing tumor cells and CD8+ T cells displaying markers of an activated dysfunctional phenotype. Finally, inhibition of MNK1/2 combined with anti-PD-1 therapy blocked lung metastasis of PPBC. These findings implicate the involvement of the MNK1/2-eIF4E axis during PPBC metastasis and suggest a promising immunomodulatory route to enhance the efficacy of immunotherapy by blocking phospho-eIF4E. SIGNIFICANCE: This study investigates the MNK1/2-eIF4E signaling axis in tumor and stromal cells in metastatic breast cancer and reveals that MNK1/2 inhibition suppresses metastasis and sensitizes tumors to anti-PD-1 immunotherapy.

Inhibiting the MNK1/2-eIF4E axis impairs melanoma phenotype switching and potentiates antitumor immune responses.

Melanomas commonly undergo a phenotype switch, from a proliferative to an invasive state. Such tumor cell plasticity contributes to immunotherapy resistance; however, the mechanisms are not completely understood and thus are therapeutically unexploited. Using melanoma mouse models, we demonstrated that blocking the MNK1/2-eIF4E axis inhibited melanoma phenotype switching and sensitized melanoma to anti-PD-1 immunotherapy. We showed that phospho-eIF4E-deficient murine melanomas expressed high levels of melanocytic antigens, with similar results verified in patient melanomas. Mechanistically, we identified phospho-eIF4E-mediated translational control of NGFR, a critical effector of phenotype switching. Genetic ablation of phospho-eIF4E reprogrammed the immunosuppressive microenvironment, exemplified by lowered production of inflammatory factors, decreased PD-L1 expression on dendritic cells and myeloid-derived suppressor cells, and increased CD8+ T cell infiltrates. Finally, dual blockade of the MNK1/2-eIF4E axis and the PD-1/PD-L1 immune checkpoint demonstrated efficacy in multiple melanoma models regardless of their genomic classification. An increase in the presence of intratumoral stem-like TCF1+PD-1+CD8+ T cells, a characteristic essential for durable antitumor immunity, was detected in mice given a MNK1/2 inhibitor and anti-PD-1 therapy. Using MNK1/2 inhibitors to repress phospho-eIF4E thus offers a strategy to inhibit melanoma plasticity and improve response to anti-PD-1 immunotherapy.

MNK1 signaling induces an ANGPTL4-mediated gene signature to drive melanoma progression.

The BRAFV600E mutation occurs in more than 50% of cutaneous melanomas, and results in the constitutive activation of the mitogen-activated protein kinases (MAPK) pathway. MAP kinase-interacting serine/threonine-protein kinase 1 and 2 (MNK1/2) are downstream effectors of the activated MAPK pathway, and important molecular targets in invasive and metastatic cancer. Despite the well-known role of MNK1 in regulating mRNA translation, little is known concerning the impact of its aberrant activation on gene transcription. Here, we show that changes in the activity, or abundance, of MNK1 result in changes in the expression of pro-oncogenic and pro-invasive genes. Among the MNK1-upregulated genes, we identify Angiopoietin-like 4 (ANGPTL4), which in turn promotes an invasive phenotype via its ability to induce the expression of matrix metalloproteinases (MMPs). Using a pharmacologic inhibitor of MNK1/2, SEL201, we demonstrate that BRAFV600E-mutated cutaneous melanoma cells are reliant on MNK1/2 for invasion and lung metastasis.

Impact of preoperative fractional flow reserve on arterial bypass graft anastomotic function: the IMPAG trial.

AIMS: Visual estimation is the most commonly used method to evaluate the degree of coronary artery stenosis prior to coronary artery bypass grafting. In interventional cardiology, the use of fractional flow reserve (FFR) to guide revascularization decisions has become routine. We investigated whether the preoperative FFR measurement of coronary lesions is associated with anastomosis function 6 months after surgical revascularization using a multiarterial grafting strategy. METHODS AND RESULTS: In this prospective double-blind study, 67 patients were enrolled from two institutions in Europe and Canada. From these patients, 199 coronary lesions were assessed visually and with FFR at the time of the preoperative angiogram. All patients received coronary revascularization using multiple arterial grafts. A post-operative 6-month angiogram was performed to assess anastomosis functionality using a described angiographic method. The primary outcome was the association between preoperative FFR values and anastomosis function 6 months after surgery. Preoperative FFR was significantly associated with 6-months anastomotic function for all conduits and for all targets (P < 0.001). An FFR value of ≤0.78 was associated with an anastomotic occlusion rate of 3%. CONCLUSION: We found a significant association between the preoperative FFR measurement of the target vessel and the anastomotic functionality at 6 months, with a cut-off of 0.78. Integration of FFR measurement into the preoperative diagnostic workup before multiarterial coronary surgical revascularization leads to improved anastomotic graft function. CLINICAL TRIALS. GOV IDENTIFIER: NCT02527044.

Association between sella turcica bridging and palatal canine impaction: Evaluation using lateral cephalograms and CBCT.

INTRODUCTION: The purpose of this study was to find a correlation between sella turcica bridging and the presence of a palatal impacted canine, using lateral cephalograms and CBCT. MATERIAL AND METHOD: We selected the lateral cephalograms and CBCTs of 60 patients meeting specific criteria. The radiographs were analysed to study the relationship between sella turca bridging and several factors. The presence or absence of a partial or total bridging was deducted by measuring the dimensions of the sella turcica and by using an accurate scoring system. RESULTS AND CONCLUSION: Our study did not show any statistically significant association between sella turcica bridging as diagnosed on the lateral cephalogram and the CBCT images and the following factors: age, gender, facial type, skeletal class and the presence of an impacted canine. We found a significant difference for the classification of the sella turcica between these two radiographic methods.

A mutation update on the LDS-associated genes TGFB2/3 and SMAD2/3.

The Loeys-Dietz syndrome (LDS) is a connective tissue disorder affecting the cardiovascular, skeletal, and ocular system. Most typically, LDS patients present with aortic aneurysms and arterial tortuosity, hypertelorism, and bifid/broad uvula or cleft palate. Initially, mutations in transforming growth factor-ß (TGF-ß) receptors (TGFBR1 and TGFBR2) were described to cause LDS, hereby leading to impaired TGF-ß signaling. More recently, TGF-ß ligands, TGFB2 and TGFB3, as well as intracellular downstream effectors of the TGF-ß pathway, SMAD2 and SMAD3, were shown to be involved in LDS. This emphasizes the role of disturbed TGF-ß signaling in LDS pathogenesis. Since most literature so far has focused on TGFBR1/2, we provide a comprehensive review on the known and some novel TGFB2/3 and SMAD2/3 mutations. For TGFB2 and SMAD3, the clinical manifestations, both of the patients previously described in the literature and our newly reported patients, are summarized in detail. This clearly indicates that LDS concerns a disorder with a broad phenotypical spectrum that is still emerging as more patients will be identified. All mutations described here are present in the corresponding Leiden Open Variant Database.

Modular neck total hip arthroplasty - a perfect storm.

PURPOSE: This study was aimed to highlight neck notching as a potential cause of failure in modular neck total hip arthroplasty. It aimed to identify both the combination of modular components that place patients at greatest risk of failure and the potential mechanism for failure. METHODS: This study involved a retrospective review of 301 total hip arthroplasties (THA) using Kinectiv modular neck Technology (Zimmer, Warsaw, Indiana). The primary outcome was the presence of neck notching requiring revision. Patient records, operative notes and postoperative radiographs were reviewed. A statistical analysis was performed. RESULTS: A total of 301 THA were performed on 290 patients. There were 7 failures (2.3%). All 7 failures involved a modular combination of an anteverted neck, extended offset and length code -8 (failure rate of 36.8%, p<0.001). CONCLUSIONS: We identified femoral neck notching as a potential cause of failure in modular neck THA. The combination of an anteverted neck, extended offset and length code -8 was associated with a high rate of neck notching using the Kinectiv modular neck Technology (Zimmer, Warsaw, Indiana). Based on our experience with this prosthesis we advise caution when using this particular combination of implants.

[Hemophacocytic syndrome as early sign for hepatosplenic T-cell lymphoma in a patient with chronic lymphocytic leukaemia]. / Syndrome d'activation macrophagique révélateur d'un lymphome T hépatosplénique chez une patiente atteinte de leucémie lymphoïde chronique.

Hepatosplenic T-cell lymphoma (HSCTL) is rare and caracterised by gama/delta T-lymphocyte proliferation in the spleen, bone marrow and liver. Association between HSCTL and hemophagocytic syndrome is known, but association with chronic lymphoid leukaemia (CLL) has not been described to our knowledge. We report the case of a 76 year's old woman, with untreated CLL, presenting with febrile pancytopenia and splenomegaly. First test revealed a hemophagocytic syndrome without CLL transformation, and with a spontaneous and favorable evolution. Fever and cytopenias recur one month later. We find then a atypical circulating lymphocyte T population, negative for CD4 and CD8. The marrow immuno-phenotyping reveals a T CD4-CD8- gamma/delta lymphoid infiltration, leading to the diagnostic of HSTCL.

Exclusive percutaneous approach for surgical transaortic transcatheter valve replacement.

Direct transaortic implantation (TAo) has been described as a new alternative approach for transcatheter aortic valve implantation in patients with unsuitable transfemoral access. TAo is usually achieved through an upper ministernotomy or, more recently, through a right thoracotomy in the second intercostal space. We describe here our first experience with a fully thoracoscopic approach that allowed successful deployment of a 23-mm Edwards SAPIEN valve.

Embol-X intraaortic filter and transaortic approach for improved cerebral protection in transcatheter aortic valve implantation.

Techniques for transcatheter aortic valve implantation involve manipulation of the native aortic valve and the aortic arch. As a result, excellent technical outcomes of this technique remain counterbalanced by a level of neurologic complications that remain unacceptably high. We present here a report of a new potential combined approach to reduce periprocedural neurologic events. After a 6-cm J-shaped upper-mini-sternotomy, 26-mm Sapien valve (Edwards Lifesciences, Irvine, CA) was deployed through a transaortic approach. In addition, the Embol-X device (Edwards Lifescience) was directly inserted in the distal ascending aorta was deployed during all the procedure. Postoperative evolution was clinically uneventful. Postoperative magnetic resonance imaging revealed no new ischemic lesions in this first patient.

Transaortic transcatheter aortic valve implantation with the Edwards SAPIEN valve: feasibility, technical considerations, and clinical advantages.

The randomized Partner study [1] has recently shown superiority of transfemoral transcatheter aortic valve implantation, in patients who are not candidates for surgical aortic valve replacement, when compared with conventional nonsurgical therapies. In patients who are not candidates for the transfemoral approach because of peripheral vascular disease or other contraindications, deployment of the SAPIEN valve (Edwards Lifesciences, Irvine, CA) in an antegrade fashion can be achieved through the apex of the left ventricle. However this valuable technique carries specific risks inherent to the access route. Transaortic implantation, through an upper ministernotomy, offers a new alternative that could avoid complications related to the transapical approach.

Reduced mortality in high-risk coronary patients operated off pump with preoperative intraaortic balloon counterpulsation.

BACKGROUND: Preoperative intraaortic balloon pump (IABP) counterpulsation has better outcomes compared with perioperative or postoperative insertion in critical patients, and off-pump surgical procedures have been advocated to reduce mortality in high-risk patients. However, some surgeons are reluctant to perform beating heart operations in specific patient subgroups, including those with unstable angina or patients with low ejection fraction, because of their possible perioperative hemodynamic instability. METHODS: We evaluated combined beating heart procedures and preoperative IABP in selected high-risk patients and compared our results with the predictive European System for Cardiac Operative Risk Evaluation (EuroSCORE) model. Fifty-five high-risk patients with a mean logistic EuroSCORE of 24 were prospectively enrolled and then divided into emergency (group 1, n = 25) and nonemergency (group 2, n = 30) groups. IABP was inserted immediately before operation in group 1 and the day before the procedure in group 2. RESULTS: Compared with the EuroSCORE predictive model, a dramatic decrease in mortality occurred in both groups. Group I predicted mortality was 36.8%, and observed was 20%; and group 2 predicted mortality was 15.2% and observed was 0%. No specific complications from the use of IABP were encountered. During mid-term (2 years) follow-up, no patient died from a cardiac cause or required percutaneous coronary intervention or subsequent reoperation due to incomplete revascularization. CONCLUSIONS: The combined use of preoperative intraaortic counterpulsation and beating heart intervention allows complete revascularization in high-risk patients with a important reduction in operative mortality and excellent mid-term results.