Targeting integrins in drug-resistant acute myeloid leukaemia.

Acute myeloid leukaemia (AML) continues to have a poor prognosis, warranting new therapeutic strategies. The bone marrow (BM) microenvironment consists of niches that interact with not only normal haematopoietic stem cells (HSC) but also leukaemia cells like AML. There are many adhesion molecules in the BM microenvironment; therein, integrins have been of central interest. AML cells express integrins that bind to ligands in the microenvironment, enabling adhesion of leukaemia cells in the microenvironment, thereby initiating intracellular signalling pathways that are associated with cell migration, cell proliferation, survival, and drug resistance that has been described to mediate cell adhesion-mediated drug resistance (CAM-DR). Identifying and targeting integrins in AML to interrupt interactions with the microenvironment have been pursued as a strategy to overcome CAM-DR. Here, we focus on the BM microenvironment and review the role of integrins in CAM-DR of AML and discuss integrin-targeting strategies. LINKED ARTICLES: This article is part of a themed issue on Cancer Microenvironment and Pharmacological Interventions. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.2/issuetoc.

Psoriatic Arthritis: What is Happening at the Joint?

Psoriatic arthritis (PsA) is a heterogeneous and inflammatory disease with diverse clinical manifestations, including psoriasis, nail psoriasis, peripheral joint disease, axial joint disease, enthesitis, and dactylitis. Typically, this varied clinical presentation complicates the clinician's ability to distinguish PsA from other forms of arthritis. In the synovium of individuals with PsA, upregulation of the genes WNT3A, BMPR2, and TGFBR1 results in bone erosion and new bone formation, a pattern unique to the disease. Additionally, genes associated with angiogenesis and vascularization such as VEGF and TGFB1 facilitate inflammation and joint damage. Gross pathogenesis of PsA is driven by proinflammatory cytokines, and key cytokines affecting joint structures include tumor necrosis factor-α, interleukin (IL)-6, IL-17A, IL-21, IL-22, and IL-23. Early diagnosis is critical for providing treatment that prevents irreversible disease progression and function loss. This narrative review discusses differentiation of PsA from other forms of arthritis. Additionally, we detail the role of cytokines at the joint in mediating PsA pathogenesis.Funding: Novartis Pharmaceuticals Corporation.

A Cadaveric Study for the Improvement of Thread Carpal Tunnel Release.

PURPOSE: The thread carpal tunnel release (TCTR) technique has been improved and offers more precise control in dissecting thread placement. The purpose of this cadaveric study was to test the procedure operationally and verify the modified TCTR anatomically. METHODS: Eleven unembalmed cadaver wrists underwent the transverse carpal ligament (TCL) release by using the modified TCTR technique. An experienced observer dissected each specimen and assessed for completeness of release under direct visual assessment. Injury to the superficial palmar aponeurosis (SupPA), the Berrettini and common digital nerve branches were also recorded as a secondary outcome. RESULTS: Eleven out of 11 wrists (100%) underwent the modified TCTR with complete release of the TCL. All 11 wrists were released without damage to any vital neurovascular structure including the Berrettini branch and the common digital nerves. The SupPA remained intact in all 5 wrists performed with the preservation steps. CONCLUSIONS: The modified TCTR technique demonstrated complete division of the TCL while protecting the SupPA as well as the Berrettini and common digital nerve branches. CLINICAL RELEVANCE: The modified TCTR has the potential to offer a clinically safe and effective minimally invasive procedure for complete carpal tunnel release.

Comparative genomic profiling of synovium versus skin lesions in psoriatic arthritis.

OBJECTIVE: To our knowledge, there is no broad genomic analysis comparing skin and synovium in psoriatic arthritis (PsA). Also, there is little understanding of the relative levels of cytokines and chemokines in skin and synovium. The purpose of this study was to better define inflammatory pathways in paired lesional skin and affected synovial tissue in patients with PsA. METHODS: We conducted a comprehensive analysis of cytokine and chemokine activation and genes representative of the inflammatory processes in PsA. Paired PsA synovial tissue and skin samples were obtained from 12 patients on the same day. Gene expression studies were performed using Affymetrix HGU133 Plus 2.0 arrays. Confirmatory quantitative real-time polymerase chain reaction (PCR) was performed on selected transcripts. Cell populations were assessed by immunohistochemistry and immunofluorescence. RESULTS: Globally, gene expression in PsA synovium was more closely related to gene expression in PsA skin than to gene expression in synovium in other forms of arthritis. However, PsA gene expression patterns in skin and synovium were clearly distinct, showing a stronger interleukin-17 (IL-17) gene signature in skin than in synovium and more equivalent tumor necrosis factor (TNF) and interferon-γ gene signatures in both tissues. These results were confirmed with real-time PCR. CONCLUSION: This is the first comprehensive molecular comparison of paired lesional skin and affected synovial tissue samples in PsA. Our results support clinical trial data showing that PsA skin and joint disease are similarly responsive to TNF antagonists, while IL-17 antagonists have better results in PsA skin than in PsA joints. Genes selectively expressed in PsA synovium might direct future therapies for PsA.

Intra-articular hylastan versus steroid for knee osteoarthritis.

PURPOSE: To assess the efficacy and safety of one and two intra-articular (IA) injections of the new viscosupplement, hylastan, compared with a single IA corticosteroid injection for pain due to knee osteoarthritis (OA). Hylastan is a high-molecular-weight hyaluronan derivative prepared from bacterial fermented sodium hyaluronate that was developed to remain in the joint for longer than most other viscosupplements. METHODS: This 6-month, double-blind, randomized, parallel group, multicenter trial enrolled patients aged ≥40 years who met American College of Rheumatology criteria for knee OA and had continued pain despite conservative treatment. Patients were randomized 1:1:1 to one of three arms: 2 × 4 mL hylastan (n = 129; arthrocentesis then IA hylastan Day 0, same treatment Week 2); 1 × 4 mL hylastan (n = 130; arthrocentesis then IA hylastan Day 0, arthrocentesis only Week 2); steroid (n = 132; arthrocentesis then IA methylprednisolone acetate 40 mg Day 0, arthrocentesis only Week 2). Participants and evaluators were blinded to treatment. The primary clinical outcome measure was change from baseline in WOMAC A pain score over all postbaseline visits to Week 26. RESULTS: Statistically significant pain reduction was observed in all three arms, with similar mean (95 % CI) changes in WOMAC A: 2 × 4 mL hylastan -0.9 (-1.0, -0.7); 1 × 4 mL hylastan -0.8 (-0.9, -0.7); steroid -0.9 (-1.0, -0.8); all P < 0.0001 versus baseline. Changes in secondary outcomes (OMERACT-OARSI and WOMAC A responder rates, patient/clinical observer global assessments, and WOMAC A1 walking pain) were similar in all three arms. Target knee adverse events were comparable for all treatments. CONCLUSIONS: Both IA hylastan injection regimens were effective in relieving pain with an acceptable safety profile. IA hylastan did not show a difference versus IA corticosteroid; therefore, the hypothesis of superior pain relief was not met. Further research is needed to compare the efficacy and safety of hylastan with other viscosupplements.

Lymphotoxin-alphabeta heterotrimers are cleaved by metalloproteinases and contribute to synovitis in rheumatoid arthritis.

Tumor necrosis factor-superfamily (TNF-SF) members, lymphotoxin (LT)-alpha and LTbeta, are proinflammatory cytokines associated with pathology in rheumatoid arthritis. LTalpha3 homotrimers are secreted, whereas LTalpha(1)beta(2) heterotrimers are expressed on the surface of activated lymphocytes. As many TNF-SF members are actively cleaved from cell membranes, we determined whether LTalphabeta heterotrimers are also cleaved, and are biologically active in rheumatoid arthritis (RA) patients. LTalphabeta heterotrimers were detected in culture supernatants from activated human T-helper (Th) 0, Th1, and Th17 cells, together with LTalpha3 and TNFalpha. The heterotimers were actively cleaved from the cell surface by ADAM17 metalloproteinase (MMP) and MMP-8, and cleavage was inhibited by TAPI-1, a TNF-alpha converting enzyme (TACE) inhibitor. Soluble LTalphabeta was detected in serum from both normal donors and RA patients, and was elevated in synovial fluid from RA patients compared to osteoarthritis (OA) patients. Levels of LTalphabeta in RA patient synovial fluid correlated with increased TNFalpha, IL-8, IL-12, IL-1beta, IFN-gamma, and IL-6 cytokines. Moreover, recombinant LTalpha1beta2-induced CXCL1, CXCL2, IL-6, IL-8, VCAM-1, and ICAM-1 from primary synovial fibroblasts isolated from RA patients. Therefore, soluble LTalphabeta in synovial fluid is associated with a proinflammatory cytokine milieu that contributes to synovitis in RA.

Safety, tolerability, and clinical outcomes after intraarticular injection of a recombinant adeno-associated vector containing a tumor necrosis factor antagonist gene: results of a phase 1/2 Study.

OBJECTIVE: To assess safety and clinical outcomes in patients with inflammatory arthritis after intraarticular (IA) injection of rAAV2-TNFR:Fc, a recombinant adeno-associated viral vector containing the human tumor necrosis factor (TNF) receptor-immunoglobulin (IgG1) Fc fusion (TNFR:Fc) gene. METHODS: In this phase 1/2 randomized study, adults with persistent moderate or severe inflammation in a target joint, being treated with or without systemic anti-TNF therapy, received a single IA injection of either rAAV2-TNFR:Fc (1 x 10(11), 1 x 10(12), or 1 x 10(13) DNase-resistant particles/ml joint volume) or placebo, followed by open-label rAAV2-TNFR:Fc 12-30 weeks later, depending on when the target joint met predetermined criteria for reinjection. RESULTS: 127 subjects received the first injection of blinded study drug; 95 subjects received open-label rAAV2-TNFR:Fc. Administration site reactions, consisting of transient mild to moderate increases in tenderness and swelling of the injected joint, occurred after 23/191 (12%) rAAV2-TNFR:Fc injections and were dose-dependent. Rates of other adverse events were not dose-dependent. Notable serious adverse events (SAE) included culture-negative septic arthritis in a subject receiving leflunomide and fatal disseminated histoplasmosis considered unrelated to rAAV2-TNFR:Fc in a subject receiving adalimumab. In the phase 2 portion of the study, a 30% decrease in target joint global visual analog scale was observed in 21/50 (42%) rAAV2-TNFR:Fc subjects and 3/16 (19%) placebo subjects 12 weeks after first injection (p = 0.14). CONCLUSION: IA rAAV2-TNFR:Fc resulted in administration site reactions after 12% of injections. A fatal SAE, disseminated histoplasmosis, was considered not related to study agent. Patient-reported outcome measures of clinical response showed greater improvement in treated patients than placebo patients.