Effect of retinoic acid on human adrenal corticosteroid synthesis.

AbstractAimsRetinoic acid has recently yielded promising results in the treatment of Cushing's disease, i.e., excess cortisol secretion due to a pituitary corticotropin (ACTH)-secreting adenoma. In addition to its effect on the tumoral corticotrope cell, clinical results suggest an additional adrenal site of action. Aim of this study was to evaluate whether retinoic acid modulates cortisol synthesis and secretion by human adrenals in vitro.Main methodsPrimary cultures from 10 human adrenals specimens were incubated with 10nM, 100nM and 1μM retinoic acid with and without 10nM ACTH for 24h. Cortisol levels were measured by radioimmunoassay and CYP11A1, STAR and MC2R gene expression analyzed by real-time PCR.Key findingsRetinoic acid increased cortisol secretion (149.5±33.01%, 151.3±49.45% and 129.3±8.32% control secretion for 10nM, 100nM and 1μM respectively, p<0.05) and potentiated STAR expression (1.51±0.22, 1.56±0.15 and 1.59±0.14 fold change over baseline, for 10nM, 100nM and 1μM respectively, p<0.05). Concurrently, retinoic acid markedly blunted constitutional and ACTH-induced MC2R expression (0.66±0.11, 0.62±0.08 and 0.53±0.07 fold change over baseline, for 10nM, 100nM and 1μM respectively, p<0.05; 0.71±0.10, 0.51±0.07 and 0.51±0.08 fold change over ACTH alone, for 10nM, 100nM and 1μM respectively, p<0.05). No effect on CYP11A1 was observed.SignificanceRetinoic acid stimulates cortisol synthesis and secretion in human adrenals and at the same time markedly blunts ACTH receptor transcription. These results reveal a novel, adrenal effect of retinoic acid which may contribute to its efficacy in patients with Cushing's disease

Insulin Receptor Isoform A and Insulin-like Growth Factor II as Additional Treatment Targets in Human Osteosarcoma

Abstract Despite the frequent presence of an insulin-like growth factor I receptor (IGFIR)-mediated autocrine loop in osteosarcoma (OS), interfering with this target was only moderately effective in preclinical studies. Here, we considered other members of the IGF system that might be involved in the molecular pathology of OS. We found that, among 45 patients with OS, IGF-I and IGFBP-3 serum levels were significantly lower, and IGF-II serum levels significantly higher, than healthy controls. Increased IGF-II values were associated with a decreased disease-free survival. After tumor removal, both IGF-I and IGF-II levels returned to normal values. In 23 of 45 patients, we obtained tissue specimens and found that all expressed high mRNA level of IGF-II and &gt;IGF-I. Also, isoform A of the insulin receptor (IR-A) was expressed at high level in addition to IGFIR and IR-A/IGFIR hybrids receptors (HRA). These receptors were also expressed in OS cell lines, and simultaneous impairment of IGFIR, IR, and Hybrid-Rs by monoclonal antibodies, siRNA, or the tyrosine kinase inhibitor BMS-536924, which blocks both IGFIR and IR, was more effective than selective anti-IGFIR strategies. Also, anti–IGF-II-siRNA treatment in low-serum conditions significantly inhibited MG-63 OS cells that have an autocrine circuit for IGF-II. In summary, IGF-II rather than IGF-I is the predominant growth factor produced by OS cells, and three different receptors (IR-A, HRA, and IGFIR) act complementarily for an IGF-II–mediated constitutive autocrine loop, in addition to the previously shown IGFIR/IGF-I circuit. Cotargeting IGFIR and IR-A is more effective than targeting IGF-IR alone in inhibiting OS growth. [Cancer Res 2009;69(6):2443–52

Establishment of a protocol to extend the lifespan of human hormone-secreting pituitary adenoma cells

Purpose The aim of this study was to generate immortalized human anterior pituitary adenoma cells. Reliable cell models for the study of human pituitary adenomas are as yet lacking and studies performed so far used repeated passaging of freshly excised adenomas, with the attendant limitations due to limited survival in culture, early senescence, and poor reproducibility. Methods &amp; Results We devised a technique based upon repeated co-transfections of two retroviral vectors, one carrying the catalytic subunit of human telomerase, hTERT, the other SV40 large T antigen. This approach extended the lifespan of cells derived from a human growth hormone-secreting adenoma up to 18 months while retaining morphology of primary cells, growth hormone synthesis and growth hormone secretion. Conclusions Our attempt represents the first demonstration of successful lifespan extension of human growth hormone-secreting pituitary adenoma cells via co-transfection of hTERT and SV40T and paves the way to future attempts to obtain stable cell lines

Divergence Between Clinical Trial Evidence and Actual Practice in Use of Dual Antiplatelet Therapy After Transient Ischemic Attack and Minor Stroke

Background: Randomized controlled trials (RCTs) proved that short-term (21-90 days) dual antiplatelet therapy (DAPT) reduces the risk of early ischemic recurrences after a noncardioembolic minor stroke or high-risk transient ischemic attack (TIA) without substantially increasing the hemorrhagic risk. We aimed at understanding whether and how real-world use of DAPT differs from RCTs. Methods: READAPT (Real-Life Study on Short-Term Dual Antiplatelet Treatment in Patients With Ischemic Stroke or TIA) is a prospective cohort study including &gt;18-year-old patients treated with DAPT after a noncardioembolic minor ischemic stroke or high-risk TIA from 51 Italian centers. The study comprises a 90-day follow-up from symptom onset. In the present work, we reported descriptive statistics of baseline data of patients recruited up to July 31, 2022, and proportions of patients who would have been excluded from RCTs. We compared categorical data through the χ² test. Results: We evaluated 1070 patients, who had 72 (interquartile range, 62-79) years median age, were mostly Caucasian (1045; 97.7%), and were men (711; 66.4%). Among the 726 (67.9%) patients with ischemic stroke, 226 (31.1%) did not meet the RCT inclusion criteria because of National Institutes of Health Stroke Scale score &gt;3 and 50 (6.9%) because of National Institutes of Health Stroke Scale score &gt;5. Among the 344 (32.1%) patients with TIA, 69 (19.7%) did not meet the RCT criteria because of age, blood pressure, clinical features, duration of TIA, presence of diabetes score &lt;4 and 252 (74.7%) because of age, blood pressure, clinical features, duration of TIA, presence of diabetes score &lt;6 and no symptomatic arterial stenosis. Additionally, 144 (13.5%) patients would have been excluded because of revascularization procedures. Three hundred forty-five patients (32.2%) did not follow the RCT procedures because of late (&gt;24 hours) DAPT initiation; 776 (72.5%) and 676 (63.2%) patients did not take loading doses of aspirin and clopidogrel, respectively. Overall, 84 (7.8%) patients met the RCT inclusion/exclusion criteria. Conclusions: The real-world use of DAPT is broader than RCTs. Most patients did not meet the RCT criteria because of the severity of ischemic stroke, lower risk of TIA, late DAPT start, or lack of antiplatelet loading dose. Registration: URL: https://www. Clinicaltrials: gov; Unique identifier: NCT05476081