MicroRNA-135a regulates NHE9 to inhibit proliferation and migration of glioblastoma cells

Abstract Background Glioblastoma multiformae (GBM) is the most aggressive type of malignant brain tumor with complex molecular profile. Overexpression of Na+/H+ Exchanger isoform 9 (NHE9) promotes tumor progression and correlates positively with insensitivity to radiochemotherapy and poor prognosis. However, molecular mechanisms responsible for increase in NHE9 levels beyond a critical threshold have not been identified. Methods Bioinformatics analysis, luciferase reporter assays, real-time PCR and western blotting were conducted to examine the expression profiles and identify microRNAs (miRNA) that target NHE9. Cell proliferation and migration assays were conducted in U87 glioblastoma cells to determine the consequence of miRNA mediated targeting of NHE9. Endosomal pH measurements, immunofluorescence microscopy and surface biotinylation experiments were conducted to characterize the mechanistic basis of regulation. Results We show that microRNA 135a (miR-135a) targets NHE9 to downregulate its expression in U87 cells. MiR-135a levels are significantly lower in glioblastoma cells compared to normal brain tissue. Downregulation of NHE9 expression by miR-135a affects proliferative and migratory capacity of U87 cells. Selectively increasing NHE9 expression in these cells restored their ability to proliferate and migrate. We demonstrate that miR-135a takes a two-pronged approach affecting epidermal growth factor receptors (EGFRs) to suppress tumor cell growth and migration. EGFR activity is a potent stimulator of oncogenic signaling. While miR-135a targets EGFR transcripts to decrease the total number of receptors made, by targeting NHE9 it routes the few EGFRs made away from the plasma membrane to dampen oncogenic signaling. NHE9 is localized to sorting endosomes in glioblastoma cells where it alkalinizes the endosome lumen by leaking protons. Downregulation of NHE9 expression by miR-135a acidifies sorting endosomes limiting EGFR trafficking to the glioblastoma cell membrane. Conclusions We propose downregulation of miR-135a as a potential mechanism underlying the high NHE9 expression observed in subset of glioblastomas. Future studies should explore miR-135a as a potential therapeutic for glioblastomas with NHE9 overexpression.https://deepblue.lib.umich.edu/bitstream/2027.42/140393/1/12964_2017_Article_209.pd

Reliability modeling of transmission and distribution systems including dependent failures

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The Impact of External Beam Radiation Therapy on Shoulder Surgical Outcomes: A Case Series Study

PURPOSE: External beam radiation therapy (XRT) is a commonly used treatment adjunct in patients with breast cancer, and is known to cause soft tissue dysfunction. However, data on XRT as a preoperative risk factor for shoulder surgery is limited. The purpose of this study is to assess whether prior history of breast cancer treated with XRT has an impact on surgical complications or outcomes. METHODS: A 20-year, retrospective chart review across one large, academic health care system was performed. Inclusion criteria comprised any patient with history of breast cancer of the upper-outer or axillary region treated with XRT. Patients also must have undergone a surgical procedure to the ipsilateral shoulder with at least 1-year postoperative follow-up. Patients were stratified by demographics, hand-dominance, and surgery type. Postoperative outcomes including range of motion (ROM) and visual analogue scale (VAS) for pain were also collected. RESULTS: Eighteen patients were identified (100% female) with an average age of 66.3 years (standard deviation 10.5 years). Ten shoulders underwent rotator cuff repair (RCR), four total shoulder arthroplasty (TSA), three Reverse Shoulder Arthroplasty (RSA) and one arthroscopic superior labrum anterior and posterior (SLAP) repair. Four patients treated with RCR (40%) experienced postoperative complications related to their procedure. These included scapular winging, adhesive capsulitis, stiffness, and one re-tear. Two patients treated with shoulder arthroplasty (28.6%) experienced postoperative complications which included lymphedema and peri-prosthetic fracture following a mechanical fall in one RSA patient and peri-prosthetic infection in one TSA patient. ROM across all groups improved, most significantly in forward flexion and internal rotation among RCR patients (p\u3c0.001). Furthermore, a statistically significant improvement in VAS scores was achieved in each group (6.2 ± 2.14 preop, 1.06 ± 1.75 postop p\u3c0.001). CONCLUSION: When compared to national averages, complication rates in our cohort were higher (40% vs. 10-17% in RCR patients and 28.6% vs. 4-14% in arthroplasty patients). Upon further scrutiny, many of these complications were independent of a history of XRT and many resolved with appropriate therapy. Most importantly, functional outcomes as measured by ROM and pain scores showed appropriate improvement consistent with normal populations without history of XRT. Thus, our results suggest that performing shoulder surgery after ipsilateral XRT for breast cancer is likely safe, may offer improved pain and improved ROM compared to forgoing surgery without necessarily increasing the risk for postoperative complication

Time-to-Surgery and Short-Term Outcomes of Trimalleolar Ankle Fracture During the COVID-19 Pandemic

PURPOSE: The purpose of this study was to evaluate the impact of the Coronavirus Disease 2019 (COVID-19) pandemic on time-to-surgery, complication rates, and functional outcomes of open reduction and internal fixation (ORIF) for trimalleolar ankle fracture. METHODS: This retrospective cohort study compared patients who underwent ORIF for trimalleolar ankle fracture between April and July of 2020 of the COVID-19 pandemic (COVID group) to a pre-pandemic cohort treated in 2018 (2018 group). Demographic information, fracture characteristics, and surgical outcomes were collected from patients’ medical charts. RESULTS: The COVID and 2018 groups consisted of 32 and 100 patients, respectively. The two groups were similar with regards to age, sex, race, income, marital status, and incidence of diabetes (p\u3e0.05). The COVID group had a higher incidence of tibiofibular syndesmotic injury (p\u3c0.01), comminution of the posterior malleolus (p\u3c0.05), and smoking (P\u3c0.01). Time-to-surgery was not significantly different between the two groups (8.84 ± 6.78 days in 2020 vs 8.61 ± 6.02 days in 2018, p=0.85). 25% (8/32) of patients in the COVID group experienced one or more postoperative complications compared to 15% (15/100) in the 2018 group (p=0.19). Mean VAS pain scores, ankle strength, and ROM in ankle plantarflexion were not significantly different between the two groups at 3 and 6 months postoperatively (p\u3e0.05). DISCUSSION: Patients who underwent ORIF for trimalleolar ankle fracture during the early months of the COVID-19 pandemic did not experience prolonged time-to-surgery and had similar outcomes compared to patients treated prior to the pandemic

Safety and efficacy of eculizumab in anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis (REGAIN): a phase 3, randomised, double-blind, placebo-controlled, multicentre study

Background Complement is likely to have a role in refractory generalised myasthenia gravis, but no approved therapies specifically target this system. Results from a phase 2 study suggested that eculizumab, a terminal complement inhibitor, produced clinically meaningful improvements in patients with anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis. We further assessed the efficacy and safety of eculizumab in this patient population in a phase 3 trial. Methods We did a phase 3, randomised, double-blind, placebo-controlled, multicentre study (REGAIN) in 76 hospitals and specialised clinics in 17 countries across North America, Latin America, Europe, and Asia. Eligible patients were aged at least 18 years, with a Myasthenia Gravis-Activities of Daily Living (MG-ADL) score of 6 or more, Myasthenia Gravis Foundation of America (MGFA) class II\ue2\u80\u93IV disease, vaccination against Neisseria meningitides, and previous treatment with at least two immunosuppressive therapies or one immunosuppressive therapy and chronic intravenous immunoglobulin or plasma exchange for 12 months without symptom control. Patients with a history of thymoma or thymic neoplasms, thymectomy within 12 months before screening, or use of intravenous immunoglobulin or plasma exchange within 4 weeks before randomisation, or rituximab within 6 months before screening, were excluded. We randomly assigned participants (1:1) to either intravenous eculizumab or intravenous matched placebo for 26 weeks. Dosing for eculizumab was 900 mg on day 1 and at weeks 1, 2, and 3; 1200 mg at week 4; and 1200 mg given every second week thereafter as maintenance dosing. Randomisation was done centrally with an interactive voice or web-response system with patients stratified to one of four groups based on MGFA disease classification. Where possible, patients were maintained on existing myasthenia gravis therapies and rescue medication was allowed at the study physician's discretion. Patients, investigators, staff, and outcome assessors were masked to treatment assignment. The primary efficacy endpoint was the change from baseline to week 26 in MG-ADL total score measured by worst-rank ANCOVA. The efficacy population set was defined as all patients randomly assigned to treatment groups who received at least one dose of study drug, had a valid baseline MG-ADL assessment, and at least one post-baseline MG-ADL assessment. The safety analyses included all randomly assigned patients who received eculizumab or placebo. This trial is registered with ClinicalTrials.gov, number NCT01997229. Findings Between April 30, 2014, and Feb 19, 2016, we randomly assigned and treated 125 patients, 62 with eculizumab and 63 with placebo. The primary analysis showed no significant difference between eculizumab and placebo (least-squares mean rank 56\uc2\ub76 [SEM 4\uc2\ub75] vs 68\uc2\ub73 [4\uc2\ub75]; rank-based treatment difference \ue2\u88\u9211\uc2\ub77, 95% CI \ue2\u88\u9224\uc2\ub73 to 0\uc2\ub796; p=0\uc2\ub70698). No deaths or cases of meningococcal infection occurred during the study. The most common adverse events in both groups were headache and upper respiratory tract infection (ten [16%] for both events in the eculizumab group and 12 [19%] for both in the placebo group). Myasthenia gravis exacerbations were reported by six (10%) patients in the eculizumab group and 15 (24%) in the placebo group. Six (10%) patients in the eculizumab group and 12 (19%) in the placebo group required rescue therapy. Interpretation The change in the MG-ADL score was not statistically significant between eculizumab and placebo, as measured by the worst-rank analysis. Eculizumab was well tolerated. The use of a worst-rank analytical approach proved to be an important limitation of this study since the secondary and sensitivity analyses results were inconsistent with the primary endpoint result; further research into the role of complement is needed. Funding Alexion Pharmaceuticals