109 research outputs found
Effects of interferons α/β on the proliferation of human micro- and macrovascular endothelial cells
No full textSynthetic interferons (IFNs) are used in the treatment of several types of cancer. In addition to an antitumor effect, IFNs show antiangiogenic activity. The aim of this study was to investigate the effects of IFN-α and IFN-β on human micro- and macrovascular endothelial cells in vitro [human micro vascular lung endothelial cells (HMVEC-L) and human umbilical cord endothelial cells (HUVEC)]. By immunohistochemical staining and quantitative reverse transcriptase (RT)-polymerase chain reaction, we studied expression of type I IFN receptors. We evaluated the effects of IFN-α and IFN-β on the proliferation (DNA content), apoptosis (DNA fragmentation by enzyme-linked immunosorbent assay), and cell cycle distribution (flow-cytometric analysis) of endothelial cells. HUVEC and HMVEC-L cells show comparable expression level of the distinct IFN receptor subtypes. Proliferation of HMVEC-L and HUVEC was inhibited by IFN-β (the half maximal inhibitory concentration [IC(50)] = 60 and 90 IU/mL, respectively), but not by IFN-α at a dose up to 1,000 IU/mL. An interesting and unexpected observation was an inhibition of apoptosis by IFN-β. After 72 h of treatment with IFN-β. Cell cycle inhibition occurs in late S-phase in both cell lines. In conclusion, only IFN-β, not IFN-α (10-1,000 IU/mL), has an inhibitory activity on endothelial cell proliferation. Surprisingly, apoptosis was decreased by IFN treatment, whereas inhibition of proliferation is caused by cell cycle arrest in late S-phas
Effects of combination treatment with sirolimus and mitotane on growth of human adrenocortical carcinoma cells
No full textDigital quantification of somatostatin receptor subtypes 2 and 5 in growth hormone–secreting pituitary tumors
No full textImmunohistochemistry (IHC) of somatostatin receptor subtype 2 can predict response to first-generation somatostatin receptor ligands (fg-SRLs) in acromegaly. Recently, we validated an open-source digital image analysis (DIA) to quantify somatostatin receptor subtype 2 (SSTR2) expression. We aimed to validate the DIA also on somatostatin receptor subtype 5 (SSTR5) in a new cohort of growth hormone (GH)-secreting pituitary tumors, with IHC performed in a different laboratory, and to correlate fg-SRL response with SSTs expression. Somatostatin receptor subtype 2 and SSTR5 were assessed in 42 GH-secreting pituitary tumors, using a semiquantitative immunoreactivity score (IRS) and the DIA by use of the open-access software CellProfiler. The DIA calculates the staining intensity and the percentage of positive cells (%PC). We found a good correlation between IRS and DIA for both SSTR2 and SSTR5 (P < .001), demonstrating the reliability of the DIA in this setting. Response to fg-SRL treatment correlated with SSTR2, but not SSTR5, expression. Somatostatin receptor subtype 2 expression predicted response to fg-SRL. In particular, the identified cut-offs were IRS ≥ 5 (area under the curve [AUC] 0.763; sensitivity 77%; specificity 83%); intensity/area ≥0.106 (AUC 0.833; sensitivity 92%; specificity 83%); and %PC-DIA ≥63.7% (AUC 0.917; sensitivity 92%; specificity 83%). The SSTR2 %PC correlated with treatment response only when evaluated using the DIA, showing a better performance of this method.</p
In Vitro Head-to-Head Comparison Between Octreotide and Pasireotide in GH-Secreting Pituitary Adenomas
No full textFirst-generation somatostatin analogs (SSAs), such as octreotide (OCT), are the first line medical therapy for acromegaly. Pasireotide (PAS), a newly developed SSA, has shown promising results in the treatment of acromegaly
Dissecting the In Vitro Efficacy of Octreotide and Cabergoline in GH- and GH/PRL-Secreting Pituitary Tumors
No full textContext Cabergoline (CAB) is an off-label medical therapy for acromegaly, overshadowed by first-generation somatostatin receptor ligands, eg, octreotide (OCT). Objective This was a head-to-head comparison between OCT and CAB in inhibiting growth hormone (GH) secretion in primary cultures of GH- and GH/prolactin (PRL)-secreting tumors; we also investigated the role of somatostatin (SST) and dopamine type 2 (D2R) receptor expression. Methods We evaluated the antisecretory effect of OCT and CAB, together with receptor mRNA expression, in 23 tumor cultures obtained from acromegaly patients referred to the Erasmus Medical Center (Rotterdam, The Netherlands). GH concentrations in cell culture media were determined after 72-hour OCT and CAB treatment (10 nM). Results OCT showed a slightly higher efficacy compared with CAB (GH decrease -39.5% vs -32.5%, P = 0.079). The effect of the 2 drugs was superimposable in GH/PRL co-secreting tumors (-42.1% vs -44.8%), where SST1 and D2R had a higher expression compared with the pure GH-secreting tumors (P = 0.020 and P = 0.026). OCT was more effective than CAB in 8/23 cultures, while CAB was more effective than OCT in 3/23 (CAB+ group). In CAB+ tumors, SST1 expression was higher compared with the other groups (P = 0.034). At receiver operating characteristic (ROC) curve analysis, SST1 and D2R discriminated between GH and GH/PRL co-secretion (AUC 0.856, P = 0.013; AUC 0.822, P = 0.024). SST1 was the best predictor of CAB response (>= 50% GH reduction, AUC 0.913, P = 0.006; 80% sensitivity, 94% specificity). Conclusion OCT is 5% to 10% more effective than CAB in vitro. SST1 mRNA expression can represent a reliable marker of GH/PRL co-secreting tumors showing a preferential response to CAB treatment
Ghrelin and its unacylated isoform stimulate the growth of adrenocortical tumor cells via an anti-apoptotic pathway
No full textGhrelin is expressed in normal human adrenocortical cells and induces their proliferation through growth hormone secretagogue receptor 1a (GHS-R1a). Consequently, it was of interest to us to determine whether acylated ghrelin and its predominant serum isoform, unacylated ghrelin, also act as factors for adrenocortical carcinoma cell growth. To examine a potential ghrelin-regulated system in adrenocortical tumors, we measured proliferative effects of acylated and unacylated ghrelin in the adrenocortical carcinoma cell lines SW-13 and NCI-H295R. We also examined the expression of ghrelin, GHSR1a, and corticotrophin-releasing factor receptor 2 (CRF-R2). Acylated and unacylated ghrelin in the nanomolar range dose-dependently induced adrenocortical cell growth up to 200% of untreated controls, as measured by thymidine uptake and WST1 assay. The proliferative effects of acylated and unacylated ghrelin in SW-13 cells was blocked by [D-Lys3]growth hormone-releasing peptide 6 (GHRP6), but a CRF-R2 antagonist had no effect on unacylated ghrelin growth stimulation. Cell cycle analysis suggests that acylated and unacylated ghrelin suppress the sub-G0/apoptotic fraction by up to 50%. Measurement of DNA fragmentation and caspase-3 and -7 activity in SW-13 cells confirmed that acylated and unacylated ghrelin suppress apoptotic rate. SW-13 cells express preproghrelin mRNA and secrete ghrelin, and [D-Lys3]GHRP6 suppresses their basal proliferation rate, strongly suggesting that ghrelin could act as an auto/paracrine growth factor. Acylated and unacylated ghrelin are potential auto/paracrine factors acting through an antiapoptotic pathway to stimulate adrenocortical tumor cell growth. Unacylated ghrelin-stimulated growth is suppressed by an antagonist of GHS-R1a, suggesting either that unacylated ghrelin is acylated before its action or that ghrelin, unacylated ghrelin, and [D-Lys3]GHRP-6 bind to a novel receptor in these cells
IFN-beta is a highly potent inhibitor of gastroenteropancreatic neuroendocrine tumor cell growth in vitro
No full textIFN-alpha controls hormone secretion and symptoms in human gastroenteropancreatic neuroendocrine tumors (GEP-NET) but it rarely induces a measurable tumor size reduction. The effect of other type I IFNs, e.g., IFN-beta, has not been evaluated. We compared the antitumor effects of IFN-alpha and IFN-beta in BON cells, a functioning human GEP-NET cell line. As determined by quantitative reverse transcription-PCR analysis and immunocytochemistry, BON cells expressed the active type I IFN receptor mRNA and protein (IFNAR-1 and IFNAR-2c subunits). After 3 and 6 days of treatment, IFN-beta significantly inhibited BON cell growth in a time- and dose-dependent manner. IC50 and maximal inhibitory effect on day 6 were 8 IU/mL and 98%, respectively. In contrast, the effect of IFN-alpha resulted significantly in a less potent effect (IC50: 44 IU/mL, maximal inhibition: 26%). IFN-alpha induced only cell cycle arrest, with an accumulation of the cells in S phase. IFN-beta, apart from a more potent delay in S-G2-M phase transit of the cell cycle, also induced a strong stimulation of apoptosis, evaluated by flow cytometry (Annexin V and 7-AAD) and measurement of the DNA fragmentation. Besides, only IFN-beta severely suppressed chromogranin A levels in the medium from BON cells after 6 days of treatment. In conclusion, IFN-beta is much more potent, compared with IFN-alpha, in its inhibitory effect on GEP-NET cell proliferation in vitro through the induction of apoptosis and cell cycle arrest. Further studies are required to establish whether IFN-beta has comparable potent tumor growth inhibitory effects in vivo
Potential role of type I interferons in the treatment of pituitary adenomas.
No full textCytokines, particularly those endowed with pro-inflammatory properties, are known to influence the release of anterior pituitary hormones by a direct and indirect action at the level of pituitary gland and hypothalamus. Type I interferons (IFNs) represent a group of cytokines that act through a common receptor composed by two chains (IFNAR-1 and IFNAR-2). Several in vitro and in vivo studies underline the fact that type I IFNs are involved in the regulation of the immune-endocrine circuitry. Treatment with type I IFNs of patients affected by chronic viral hepatitis, multiple sclerosis and tumors influences the secretion of pituitary hormones. This article reviews the current knowledge about the effects of IFN-alpha and IFN-beta on hypothalamic-pituitary function and describes the potential role of type I IFNs in the treatment of pituitary adenomas
Somatostatin receptor subtypes in human thymoma and inhibition of cell proliferation by octreotide in vitro
No full textSomatostatin (SS) and SS receptor (SSR) subtypes, code-named sst1-5, are
heterogeneously expressed in the normal human thymus. This suggests their
involvement in controlling the immune and/or neuroendocrine functions in
this organ. Moreover, recently a high in vivo uptake of
[111In-DTPA-D-Phe1]octreotide has been reported in patients bearing
thymoma. The present study characterizes in vivo and in vitro, functional
SS-binding sites in a human thymoma. A high uptake of
[111In-DTPA-D-Phe1]octreotide was observed in the chest of a patient with
myasthenia gravis due to a cortical thymoma. Specific binding of
[125I-Tyr11] SS-14 was found on a membrane preparation of the surgically
removed thymoma. Scatchard analysis showed high affinity binding sites
(Kd, 47.5 +/- 2.5 pmol/L) with low maximum binding capacity (23.5 +/- 2.5
fmol/mg membrane protein). RT-PCR analysis showed the presence of sst1,
sst2A, and a predominant sst3 messenger RNA (mRNA) expression in the tumor
tissue. Primary cultured tumor cells expressed sst3 mRNA only. In contrast
to the normal thymus, SS mRNA was not expressed. By immunohistochemistry,
the tumor cells highly expressed sst3 receptors, weakly expressed sst1
receptors, and showed no immunostaining for sst2A receptors. sst2A
immunoreactivity was found in the stromal compartment of the tumor,
particularly on the endothelium of small intratumoral blood vessels. In
primary cultured tumor cells, both SS and octreotide (10 nmol/L)
significantly inhibited [3H]thymidine incorporation by 40.6% and 43.2%,
respectively. The following conclusions were reached. 1) As this tumor
displayed a high immunoreactivity for sst3 and the cultured tumor cells
expressed the sst3 mRNA only, this SSR may be the subtype involved in the
inhibition of epithelial tumor cell proliferation by octreotide in vitro.
2) A loss of endogenous SS production in this thymoma might be implicated
in the uncontrolled cell growth. 3) In this case, the sst3 may play a role
in determining the uptake of [111In-DTPA-D-Phe1]octreotide by in vivo SS
receptor scintigraphy
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