6 research outputs found
Membrane-Spanning DNA Nanopores with Cytotoxic Effect.
DNA-based cytotoxic agents: Nanopores composed of folded DNA featuring a hydrophobic belt of ethyl phosphorothioate groups insert into bilayer membranes and kill cancer cells. The mode by which the pores achieve cell killing is elucidated with confocal microscopy
LRIG1 regulates cadherin-dependent contact inhibition directing epithelial homeostasis and pre-invasive squamous cell carcinoma development.
Epidermal growth factor receptor (EGFR) pathway activation is a frequent event in human carcinomas. Mutations in EGFR itself are, however, rare, and the mechanisms regulating EGFR activation remain elusive. Leucine-rich immunoglobulin repeats-1 (LRIG1), an inhibitor of EGFR activity, is one of four genes identified that predict patient survival across solid tumour types including breast, lung, melanoma, glioma, and bladder. We show that deletion of Lrig1 is sufficient to promote murine airway hyperplasia through loss of contact inhibition and that re-expression of LRIG1 in human lung cancer cells inhibits tumourigenesis. LRIG1 regulation of contact inhibition occurs via ternary complex formation with EGFR and E-cadherin with downstream modulation of EGFR activity. We find that LRIG1 LOH is frequent across cancers and its loss is an early event in the development of human squamous carcinomas. Our findings imply that the early stages of squamous carcinoma development are driven by a change in amplitude of EGFR signalling governed by the loss of contact inhibition
Cellular calcium in bipolar disorder: systematic review and meta-analysis
Calcium signalling has long been implicated in bipolar disorder, especially by reports of altered intracellular calcium ion concentrations ([Ca2+]). However, the evidence has not been appraised critically. We carried out a systematic review and meta-analysis of studies of cellular calcium indices in bipolar disorder. 2281 records were identified and 117 screened, of which 32 were eligible and 21 were suitable for meta-analyses. The latter each involved up to 642 patients and 404 control subjects. We found that basal free intracellular [Ca2+] is increased in bipolar disorder, both in platelets and in lymphocytes. The effect size is 0.55, with an estimated elevation of 29%. It is observed in medication-free patients. It is present in mania and bipolar depression, but data are equivocal for euthymia. Cells from bipolar disorder individuals also show an enhanced [Ca2+] response to stimulation with 5-HT or thrombin, by an estimated 25%, with an effect size of 0.63. In studies which included other diagnoses, intracellular basal [Ca2+] was higher in bipolar disorder than in unipolar depression, but not significantly different from schizophrenia. Functional parameters of cellular Ca2+ (e.g. calcium transients), and neuronal [Ca2+], have been much less investigated, and no firm conclusions can be drawn. In summary, there is a robust, medium effect size elevation of basal and stimulated free intracellular [Ca2+] in bipolar disorder. The results suggest altered calcium functioning in the disorder, and encourage further investigations into the underlying mechanisms, and the implications for pathophysiology and therapeutics
Gabapentin and pregabalin in bipolar disorder, anxiety states, and insomnia: systematic review, meta-analysis, and rationale
The gabapentinoids, gabapentin, and pregabalin, target the α2δ subunits of voltage-gated calcium channels. Initially licensed for
pain and seizures, they have become widely prescribed drugs. Many of these uses are off-label for psychiatric indications, and there
is increasing concern about their safety, so it is particularly important to have good evidence to justify this usage. We conducted a
systematic review and meta-analysis of the evidence for three of their common psychiatric uses: bipolar disorder, anxiety, and
insomnia. Fifty-five double-blind randomised controlled trials (RCTs) and 15 open-label studies were identified. For bipolar disorder,
four double-blind RCTs investigating gabapentin, and no double-blind RCTs investigating pregabalin, were identified. A
quantitative synthesis could not be performed due to heterogeneity in the study population, design and outcome measures. Across
the anxiety spectrum, a consistent but not universal effect in favour of gabapentinoids compared to placebo was seen
(standardised mean difference [SMD] ranging between -2.25 and -0.25). Notably, pregabalin (SMD -0.55, 95% CI -0.92 to -0.18) and
gabapentin (SMD -0.92, 95% CI -1.32 to -0.52) were more effective than placebo in reducing preoperative anxiety. In insomnia,
results were inconclusive. We conclude that there is moderate evidence of the efficacy of gabapentinoids in anxiety states, but
minimal evidence in bipolar disorder and insomnia and they should be used for these disorders only with strong justification. This
recommendation applies despite the attractive pharmacological and genetic rationale for targeting voltage-gated calcium
channels