EVI1 protein interaction dynamics: targetable for therapeutic intervention?

High expression of the transcriptional regulator EVI1 encoded at the MECOM locus at 3q26 is one of the most aggressive oncogenic drivers in acute myeloid leukaemia (AML) and carries a very poor prognosis. How EVI1 confers leukaemic transformation and chemotherapy resistance in AML is subject to important ongoing clinical and experimental studies. Recent discoveries have revealed critical details about genetic mechanisms of the activation of EVI1 overexpression and downstream events of aberrantly high EVI1 expression. Here we review and discuss aspects concerning the protein interactions of EVI1 and the related proteins MDS-EVI1 and ΔEVI1 from the perspective of their potential for therapeutic intervention.

Real-world data (RWD) reveals benefit for adjuvant chemotherapy with docetaxel, oxaliplatin and fluorouracil/leucovorin (FLOT) is limited to those with tumour regression grade (TRG) ≥3 in oesophago-gastric cancer (OGC)

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Background: Despite potentially curative surgery, long-term survival from OGC remains poor due to high relapse rate. Neoadjuvant (naFLOT) and adjuvant (aFLOT) FLOT is currently standard treatment for resectable OGC based on data from the FLOT-4 trial. We explored whether TRG was associated with FLOT-outcome using RWD. Methods: Pts with OGC treated with naFLOT +/- aFLOT at a tertiary UK centre were identified following institutional board approval. Clinical and laboratory data were extracted from the patient record. TRG was evaluated by a histopathologist. Median overall survival (OS) and median progression-free survival (PFS) were evaluated using Kaplan-Meier and Log-rank tests; time taken from start of naFLOT, and associations between factors with Fisher’s exact (FE) test. Results: 171 pts were identified, median FU 30 mths. 144 (84%) male; median age 66 (32-84); oesophagus 66 (38%), junctional (GOJ) 73 (43%), gastric 32 (19%); stage IB 3 (2%), stage IIB 26 (15%), stage III 91 (53%), stage IVA 47 (28%) and unknown 4 (2%). Pts had median of 2 comorbidities (range 0-6); performance status (PS) 0: 95 (56%), PS 1: 71 (41%), PS 2: 3 (2%) and PS unknown 2 (1%). 132/171 pts completed 4 cycles of naFLOT and this was significantly associated with undergoing surgery (p = 0.02). Those who had surgery (140/171) had significantly improved PFS (not reached (NR) vs. 6 mths; 95% CI 2-10; p < 0.001) and OS (NR vs. 12 mths; 95% CI 6-18; p < 0.001). TRG was reported for 126/140 patients who underwent surgery. TRG 1/2 (42/126) vs. TRG ≥3 was significantly associated with improved PFS (NR vs. 35 mths; 95% CI NR; p < 0.001) and OS (median NR either group; p < 0.001). Pts with TRG 1/2 who commenced aFLOT (≥1 cycle; n = 31/42) or completed 4 cycles of aFLOT (17/31) did not have improved PFS or OS vs. those who did not. Those with TRG ≥3 who commenced aFLOT (≥1 cycle; n = 62/85) had improved PFS (median NR vs. 22 mths; 95% CI 13-31 p = 0.006) and OS (median NR vs. 25 mths; 95% CI 18-32 p = 0.019). Those with TRG ≥3 who completed 4 cycles of aFLOT (n = 38/62) had significantly improved PFS (median NR vs. 25 mths; 95% CI 14-36 p = 0.016) and OS (median NR vs. 36 mths; 95% CI 16-55 p = 0.012). There was no difference in PFS or OS in pts with TRG ≥3 who had a dose reduction at any time during aFLOT. Conclusions: TRG is a predictor of outcome following naFLOT + surgery with superior outcomes in those with TRG 1/2. Our analyses suggest that only pts with TRG >3 following naFLOT + surgery benefit from adjuvant FLOT. Prospective randomised studies are required to confirm whether pts with TRG 1/2 require treatment with aFLOT.

EVI1 carboxy-terminal phosphorylation is ATM-mediated and sustains transcriptional modulation and self-renewal via enhanced CtBP1 association

The transcriptional regulator EVI1 has an essential role in early hematopoiesis and development. However, aberrantly high expression of EVI1 has potent oncogenic properties and confers poor prognosis and chemo-resistance in leukemia and solid tumors. To investigate to what extent EVI1 function might be regulated by post-translational modifications we carried out mass spectrometry- and antibody-based analyses and uncovered an ATM-mediated double phosphorylation of EVI1 at the carboxy-terminal S858/S860 SQS motif. In the presence of genotoxic stress EVI1-WT (SQS), but not site mutated EVI1-AQA was able to maintain transcriptional patterns and transformation potency, while under standard conditions carboxy-terminal mutation had no effect. Maintenance of hematopoietic progenitor cell clonogenic potential was profoundly impaired with EVI1-AQA compared with EVI1-WT, in particular in the presence of genotoxic stress. Exploring mechanistic events underlying these observations, we showed that after genotoxic stress EVI1-WT, but not EVI1-AQA increased its level of association with its functionally essential interaction partner CtBP1, implying a role for ATM in regulating EVI1 protein interactions via phosphorylation. This aspect of EVI1 regulation is therapeutically relevant, as chemotherapy-induced genotoxicity might detrimentally sustain EVI1 function via stress response mediated phosphorylation, and ATM-inhibition might be of specific targeted benefit in EVI1-overexpressing malignancies.

Memory, language, and praxis in Alzheimer's disease: norms for outpatient clinical trial populations

The cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-Cog) is designed specifically to assess memory, language, and praxis dysfunctions characteristic of Alzheimer's disease (AD). In this report, we use data from 1,648 AD participants in two identical 26-week multicenter drug trials to derive clinical trial population-based norms for ADAS-Cog subtest scores. All 11 ADAS-Cog item scores were sensitive to differences in dementia severity judged either by baseline Mini-Mental State Exam (MMSE) scores or by Global Deterioration Scale (GDS) stage of dementia. Using ADAS-Cog subtest scores alone, 85 percent of GDS 4 subjects and 69 percent of GDS 5 subjects could be classified correctly. In a stepwise discriminant analysis, orientation was the item with the greatest discriminatory power between subjects with GDS 4 and GDS 5 stages of dementia. ADAS-Cog subtest scores also varied by age, gender, educational level, and concurrent use of anti-inflammatory drugs or estrogen (in women). Such normative data may facilitate the selection of appropriate outcome measures to investigate differential treatment effects on specific cognitive domains or in specific AD subpopulations.

Nasal versus oral midazolam for sedation of anxious children undergoing laceration repair

STUDY OBJECTIVE

To compare the efficacy and safety of a single dose of midazolam, as an oral solution of 0.5 mg/kg, or nasal drops of 0.25 mg/kg, in children undergoing emergency department laceration repair.

DESIGN

Double-blind, double-placebo, randomized trial. Children underwent standard wound care when judged to demonstrate a reduction in anxiety following study medication.

PARTICIPANTS

Fifty-eight patients between 1 and 10 years of age with uncomplicated lacerations judged to be anxious by emergency physicians.

RESULTS

An anxiety score and vital signs were recorded at routine intervals. Groups were comparable with respect to age, laceration characteristics, initial vital signs, and anxiety scores. Both groups demonstrated reductions (mean +/- SD) in anxiety scores over time (P < .05; maximum at 10 minutes; 1.2 +/- 0.9 mm for nasal and 0.8 +/- 1.3 for oral), with no significant differences between groups (repeat-measures ANOVA). Median observer-rated effectiveness using a visual analog scale (maximum effectiveness, 10 mm) was not significantly different between groups: nasal, 7.6 mm and oral, 6.9 (Mann-Whitney U test: minimum detectable difference, 0.7, with alpha = 0.05 and beta = 0.2). Complications were judged to be minor only, and were more frequent in the nasal group (5 of 28, 4 with nasal burning) versus 1 of 26 in the oral group. Time from midazolam to ED discharge was not significantly different between groups: nasal, 54 +/- 15 minutes and oral, 57 +/- 16 minutes.

CONCLUSION

A single dose of oral or nasal midazolam results in reduced anxiety and few complications in selected children undergoing laceration repair in the ED. The oral route was associated with fewer administration problems.

The use of corticosteroids in croup: a survey

The use of corticosteroids to treat laryngotracheobronchitis (croup) is controversial. Although some evidence supports the efficacy of treating hospitalized patients with croup, there is no published information on the use of corticosteroids in the outpatient population. We sought to determine what the current practice in the use of corticosteroids to treat croup was in our community. One hundred thirty-eight questionnaires were mailed to pediatricians and family practitioners in our geographic region. One hundred twelve surveys were completed and returned. The majority of responding physicians used corticosteroids to treat both inpatients and outpatients with croup at least some of the time. A significantly greater percentage used them to treat hospitalized patients (93%) compared with nonhospitalized patients (68%). The drug used by the majority of respondents was dexamethasone (87% in treating inpatients, 56% in treating outpatients). The initial dosage, cumulative dosage, number of doses, and route of administration varied greatly among the respondents. This survey demonstrates that most physicians in our area are using corticosteroids to treat both hospitalized and non-hospitalized patients with croup. However, the form of drug used, dosing regimen, and route of administration are highly variable. This survey highlights the need for clinical studies to assess the efficacy of using corticosteroids to treat outpatients with croup and to determine how best to use them.

Measurement of androgen sensitivity in the human prostate in in vitro three-dimensional histoculture

We have adopted an in vitro three-dimensional histoculture technique for assay of androgen sensitivity in explants of human benign prostatic tissue. The assay is based on the uptake of 3H-thymidine/micrograms protein in explants of prostate incubated in parallel with dihydrotestosterone (DHT) and hydroxyflutamide (HF) controls. The ratio of 3H-thymidine/micrograms protein in DHT treated samples per 3H-thymidine/micrograms protein in HF treated samples provides an index of androgen sensitivity. The DHT/HF index measured in 24 BPH specimens averaged 3.6. To determine the specificity of the HF effect, we measured the DHT/HF index in a single prostate at different concentrations of HF in the presence of fixed concentrations of DHT (2 x 10(-8) M) and noted a dose-response relationship. In addition we noted no effects of HF on 3H-thymidine incorporation over a range of 2 x 10(-4)M compared to 2 x 10(-7)M, except at the highest concentration. Of surprise was the finding of an average DHT/HF index in 5 different nonprostate tissues, including breast, uterus, colon, kidney, and thyroid, that was similar to the index found in prostates. We plan to adapt this androgen sensitivity assay to measure the DHT/HF index in biopsy-size samples of prostate, since such an assay could then be utilized to determine androgen sensitivity in individual patients with prostate cancer.

Human cortical neuronal cell line: establishment from a patient with unilateral megalencephaly

A cell line has been established in continuous culture of human cerebral cortical neurons obtained from a patient with unilateral megalencephaly, a disorder associated with continued proliferation of immature neuronal cells. When differentiated in the presence of nerve growth factor, 1-isobutyl-3-methylxanthine, and dibutyryl adenosine 3',5'-monophosphate (cAMP), the cells display mature neuronal morphology with numerous long, extensively branched processes with spines and varicosities. The cells stain positively for neurofilament protein and neuron-specific enolase (selective neuronal markers) but are negative for glial markers, such as glial fibrillary acidic protein, S-100, and myelin basic protein. The cells also stain positively for the neurotransmitters gamma-aminobutyric acid (GABA), glutamate, somatostatin, cholecystokinin-8, and vasoactive intestinal polypeptide. These cells may facilitate characterization of neurons in the human central nervous system.