Transcription factor c-Myb inhibits breast cancer lung metastasis by suppression of tumor cell seeding.

Metastasis accounts for most of cancer-related deaths. Paracrine signaling between tumor cells and the stroma induces changes in the tumor microenvironment required for metastasis. Transcription factor c-Myb was associated with breast cancer (BC) progression but its role in metastasis remains unclear. Here we show that increased c-Myb expression in BC cells inhibits spontaneous lung metastasis through impaired tumor cell extravasation. On contrary, BC cells with increased lung metastatic capacity exhibited low c-Myb levels. We identified a specific inflammatory signature, including Ccl2 chemokine, that was expressed in lung metastatic cells but was suppressed in tumor cells with higher c-Myb levels. Tumor cell-derived Ccl2 expression facilitated lung metastasis and rescued trans-endothelial migration of c-Myb overexpressing cells. Clinical data show that the identified inflammatory signature, together with a MYB expression, predicts lung metastasis relapse in BC patients. These results demonstrate that the c-Myb-regulated transcriptional program in BCs results in a blunted inflammatory response and consequently suppresses lung metastasis.

Obesity reduces the pro-angiogenic potential of adipose tissue stem cell-derived extracellular vesicles (EVs) by impairing miR-126 content: impact on clinical applications.

BACKGROUND/OBJECTIVES: Soluble factors and cell-derived extracellular vesicles (EVs) are crucial tissue repair mediators in cell-based therapy. In the present study, we investigate the therapeutic impact of EVs released by adipose tissue-derived stem cells (ASCs) recovered from obese subjects' visceral and subcutaneous tissues. METHODS: ASCs were recovered from 10 obese (oASCs) and 6 non-obese (nASCs) participants and characterized. In selected experiments, nASCs and oASCs were cultured with palmitic acid (PA) or high glucose (HG), respectively. EVs from obese (oEVs) and non-obese (nEVs) subjects' visceral and subcutaneous ASCs were collected after ultracentrifugation and analyzed for their cargo: microRNA-126 (miR-126), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 2 (MMP-2), and for their biological effects on endothelial cells (ECs). Western blotting analysis and loss- and gain-of function experiments were performed. RESULTS: oEVs show impaired angiogenic potential compared with nEVs. This effect depends on EV cargo: reduced content of VEGF, MMP-2 and, more importantly, miR-126. We demonstrate, using gain- and loss-of-function experiments, that this reduced miR-126 content leads to Spred1 upregulation and the inhibition of the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase pathway in ECs. We also show that PA treatment of nASCs translates into the release of EVs that recapitulate oEV cargo. Moreover, HG treatment of oASCs further reduces miR-126 EV content and EV-mediated in vitro angiogenesis. Finally, impaired pro-angiogenic potential is also detected in EVs released from obese subcutaneous adipose tissue-derived ASCs. CONCLUSIONS: These results indicate that obesity impacts on EV pro-angiogenic potential and may raise concerns about the use of adipose tissue-derived EVs in cell-based therapy in the obese setting.

My engagement with steroids: a review.

In the course of my studies of patients with mineralocorticoid hypertensive disorders, unusual presentations led to unexpected findings, both clinically and in steroid etiologies and regulation. Unique circumstances permitted early studies in defining the autonomy of the aldosterone-producing adenoma. A chance referral brought the index case of 17 alpha-hydroxylase deficiency to the research center. New techniques were developed in unusual ways to measure the metabolites of deoxycorticosterone (DOC) using an anesthetic agent. Procedural delays were followed by the surreptitious transfer of a patient from one hospital to the research center after a benign DOC-secreting tumor had been removed. The delay of DOC and all 17-deoxysteroids to respond normally to ACTH stimulation suggested a possible second regulator of DOC. This observation led to studies that demonstrated divergent responses between DOC and cortisol in diverse conditions. An unexplained mineralocorticoid form of hypertension with suppression of renin and aldosterone, but normal DOC production, is seen in licorice intoxication. After licorice was discontinued we documented the delay in the recovery of the inhibited cortisol metabolism (14 days) and renin-angiotensin system (4 months). Licorice extract given to normal subjects on low sodium diets with and without ACTH suppression showed similar results. Other factors in licorice may thus be operative in terms of renin and aldosterone suppression.

Disorders of steroid 17 alpha-hydroxylase deficiency.

The human P450c17 alpha gene (CYP17) is a single copy gene located in chromosome 10, consisting of 8 exons and 7 introns. 17 alpha-Hydroxylase/17,20-lyase deficiency is one of two hypertensive forms of congenital adrenal hyperplasia and is inherited as an autosomal recessive trait; although rare, it probably exists with twice the frequency of the 11 beta-hydroxylase deficiency. Deficient 17 alpha-hydroxylation of pregnenolone and progesterone and subsequent deficiency of the cleavage of the C-17,20 carbon bond result in the absence of sex hormone formation in both the adrenal glands and the gonads, causing hypogonadism and male pseudohermaphroditism. Elevated and glucocorticoid-suppressible levels of the ZF 17-deoxysteroids--DOC and corticosterone--as well as their 18-hydroxylated products--18-OHDOC and 18-OHB (in addition to 19-nor-DOC)--are responsible for hypertension, hypokalemia, and renin and aldosterone suppression. A few cases, reported primarily among Japanese families, have basal hyperaldosteronism, an enigmatic condition that still demands adequate explanation. Like other forms of congenital adrenal hyperplasia, treatment of 17 alpha-hydroxylase deficiency consists of replacement doses of glucocorticoid hormones and supplemental estrogen therapy in the young adult patient. Heterozygotes may be detected by slightly exaggerated responses of some or all the ZF 17-deoxysteroids to ACTH stimulation, and by the elevated ratio of total urinary metabolites of corticosterone to the total metabolites of cortisol.

A dedicated MRI apparatus for medical and industrial applications.

So far, one of the major obstacles to the development of special purpose MRI imaging apparatus has been the lack of a magnetic technology that could cater to the need for a light, compact and efficient magnet, capable of providing the required field uniformity at a reasonable cost. Today, recent advances in magnet design permit attaining, with the use solely of ferrite, low-cost, small-scale scanners, which can open up new areas of application of MRI, in both medical and industrial fields. A novel apparatus (ARTOSCAN) is described and some examples of applications in different fields are shown. The apparatus has been designed specifically for the imaging of extremities, but possible applications on the industrial side are numerous and not yet all identified. Such a device could be used, for example, in the agricultural, food, and oil industries, where some of the needs for nondestructive quality-control devices could be fulfilled. Some tests have been performed that demonstrate the potential of the apparatus in the study of rock properties, of the drying process of pasta and wood, and to display flaws that could be present in ceramic materials before firing.

Low sodium intake enhances sensitivity of 11-deoxycortisol and deoxycorticosterone to ACTH in ACTH-suppressed normal subjects.

Continued administration of ACTH to patients with hypopituitarism produced normal increases in steroids dependent on microsomal cytochrome P450(21) and P450(17 alpha) but reduced responses of steroids dependent on mitochondrial cytochrome P450(11 beta-18). To explore possible mechanisms and to determine whether this dissociation occurs with short-term ACTH suppression, we have examined the steroid responses to ACTH after 1 h in 12 normal subjects after equilibration on sodium intakes of 124 mmol/d [normal sodium diet (NSD)], 22 mmol/d [low sodium diet (LSD)], and 240 mmol/d [high sodium diet (HSD)] before and during continued ACTH suppression with dexamethasone (DEX). Two distinct patterns of steroid responses were observed. Deoxycorticosterone (DOC) responses were initially reduced during LSD-DEX but eventually returned to the NSD-control (NSD-CONT) values; in contrast 18-hydroxydeoxycorticosterone and corticosterone remained suppressed. 11-Deoxycortisol and 21-deoxycortisol showed patterns similar to DOC, with a return to normal ACTH responses on LSD-DEX. Basal cortisol levels were reduced and the ACTH response was unchanged by LSD. HSD-DEX reduced basal levels of all steroids as well as their ACTH responses. LSD and/or increased activity of the renin-angiotensin system have a significant impact on 17 alpha- and 21-hydroxylation functions in the zona fasciculata to maintain a normal ACTH response of microsomally dependent steroids under these conditions. In contrast, on HSD-DEX with the renin-angiotensin system suppressed, there is generalized impairment of steroid responses to ACTH.

Steroid characteristics of mineralocorticoid adrenocortical hypertension.

Adrenocortical causes of hypertension are established by examining the mineralocorticoid hormones produced in the zona glomerulosa and zona fasciculata. In the zona glomerulosa, aldosterone excess leads to hypertension, hypokalemia, and suppressed plasma renin activity, with increased concentrations of urinary aldosterone (either as the 18-glucuronide or free aldosterone) as an index of its production. Identifying a tumor by computed tomography scan verifies the diagnosis of a correctable lesion. If no tumor is found, several maneuvers are used to identify primary adrenal hyperplasia, a disorder with autonomous aldosterone production, for which reduction of adrenal mass is curative. The zona fasciculata has two major pathways: the 17-deoxy pathway, where deoxycorticosterone (DOC) and corticosterone are the significant steroids, and the 17-hydroxy pathway, which leads to cortisol production. Tumors of the 17-deoxy pathway, DOC-producing adenomas, have increased concentrations of DOC and its precursor steroids, normal concentrations of cortisol, and suppression of aldosterone production secondary to suppression of the renin system. Two enzymatic defects in the zona fasciculata, 11 beta- and 17 alpha-hydroxylase deficiency, can be first readily identified by the virilization in the former, hypogonadal features in the latter. Steroid patterns are diagnostic. DOC is produced in excess in both deficiencies and is the cause of the hypertension. Deficient or impaired 11 beta-hydroxy steroid dehydrogenase in the apparent mineralocorticoid excess syndrome or after licorice ingestion retards the conversion of cortisol to inactive cortisone in the kidney, leading to mineralocorticoid hypertension; this leads to suppression of the renin system and subsequently of aldosterone.

Reassessment of the predictive value of the postural stimulation test in primary aldosteronism.

Postural stimulation tests (PST) from 146 patients with primary aldosteronism were reviewed: 83 had an aldosterone-producing adenoma (APA), 48 idiopathic hyperaldosteronism (IHA), nine primary adrenal hyperplasia (PAH), and six aldosterone-producing renin-responsive adenoma (AP-RA). Plasma aldosterone and cortisol levels were measured after overnight recumbency and in response to upright posture for 2 to 4 h. The test was considered invalid in 32% of the patients because cortisol levels increased during the maneuver. As both cortisol and aldosterone are responsive to ACTH in subjects with primary aldosteronism, as well as in normal subjects, we examined their percent variation instead of the absolute values. In order to validate those tests in which cortisol increased, we subtracted the percent cortisol change from the percent aldosterone response. An aldosterone increase of less than 30% (considered a positive response for the presence of an adenoma) identified 76 of the 89 patients with an adenoma (APA and AP-RA) (sensitivity of 85%). Among the 13 false-negative tests, six were proven cases of AP-RA. In each and every case an adenoma was detected by CT/MRI scanning (or bilateral adrenal vein catheterization). Hypertension was ameliorated or cured by surgery. A postural response of less than 30% was also present in 11 of the 57 patients who did not have a discrete adenoma confirmed by imaging techniques (specificity of 81%). Among these false-positive results there were the nine cases of PAH where the hypertension could be ameliorated or cured by partial removal of hyperplastic adrenal tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

17 alpha-hydroxylation deficiency.

Cases of sexual immaturity and male pseudohermaphroditism due to disorders such as androgen resistance, 5 alpha-reductase deficiency, cholesterol desmolase deficiency, 3 beta-hydroxysteroid dehydrogenase deficiency, and testicular and ovary dysgenesis can easily be distinguished from 17 alpha-OHD. None of these disturbances result in hypertension. In the only other form of juvenile hypertension due to congenital adrenal hyperplasia, 11 beta-OHD, androgen excess leads to female pseudohermaphroditism and precocious puberty in the male patient. Patients with dexamethasone-suppressible hyperaldosteronism present with no sexual abnormalities. A diagnosis of 17 alpha-OHD can be readily assumed in the female patient with primary amenorrhea, hypertension, and hypokalemia. The absence of aldosterone, a measurement that is readily available, establishes this diagnosis even without the measurement of DOC.

Mineralocorticoids in congenital adrenal hyperplasia.

While hypertension is observed in only two of the three major subtypes of congenital adrenal hyperplasia (CAH), 11 beta- and 17 alpha-hydroxylase deficiencies, deoxycorticosterone (DOC) production is increased in all. The elevated zona fasciculata (ZF) DOC produces mineralocorticoid hypertension with suppressed renin and reduced potassium concentrations. The DOC levels in 21-hydroxylase deficiency are in part produced by renin stimulation of the Zona glomerulosa (ZG) along with aldosterone. Assessment of the mineralocorticoid hormones of the ZF and ZF (17-deoxy steroids) provides additional unique characteristics of each subtype. Dissociation of DOC from cortisol is not unique to CAH. This dissociation is seen in other disorders and contrived conditions. There is a strong suggestion of a non-ACTH regulator of 17-deoxy steroids (DOC) that may contribute significantly to DOC production in general and effect DOC levels in CAH.

Continuous adrenocorticotropin administration in hypopituitarism produces asynchronous increases of deoxycorticosterone and 11-deoxycortisol relative to other reduced zona fasciculata steroids.

Short term suppression of ACTH by dexamethasone effects limited reduction in plasma deoxycorticosterone (DOC) while cortisol levels are almost completely suppressed in normal control subjects. The zona fasciculata (ZF) microsomal cytochrome P-450(21) appeared less influenced by lack of ACTH than mitochondrial cytochrome P-450(11 beta-18). Eleven patients with hypopituitarism were studied to quantitate basal ZF microsomal and mitochondrial derived steroids and their acute and extended responses to ACTH. Basal levels of 11-deoxycortisol (S) and DOC were modestly reduced (70% and 53%, respectively), while other ZF steroids were almost completely absent. Acute and prolonged ACTH treatment amplified the discrepancy in both plasma levels and production rates. DOC and S demonstrated prompt and sustained increases similar to those in normal controls, while cortisol, 18-hydroxydeoxycorticosterone, and corticosterone showed a slow subnormal recovery of steroid production. The preservation of microsomal cytochrome P-450(21) and P-450(17 alpha) to maintain DOC and S levels contrasts the reduced and delayed responses of steroids dependent on mitochondrial cytochrome P-450(11 beta-18), cortisol, corticosterone, and 18-hydroxydeoxycorticosterone. A greater effect of ACTH deficiency on mitochondrial over microsomal cytochrome P-450 activity is demonstrated, and in addition, the possibility is raised that other non-ACTH regulators sustain microsomal cytochrome P-450(21) and P-450(17 alpha) in a setting of reduced ACTH-stimulated factors.

Correctable subsets of primary aldosteronism. Primary adrenal hyperplasia and renin responsive adenoma.

Among 154 cases of primary aldosteronism seen in the General Clinical Research Center at San Francisco General Hospital, twelve patients did not fulfill established characteristics of an aldosterone producing adenoma (APA) or idiopathic hyperaldosteronism (IHA). Eight patients had nodular adrenocortical hyperplasia; plasma and urinary aldosterone were elevated and responses to stimulatory and suppressive maneuvers demonstrated the same autonomy seen in patients with APA. This subset is designated primary adrenal hyperplasia. Four additional patients also had elevated aldosterone levels that were responsive to these maneuvers, similar to IHA, but had unilateral tumors. This group has been designated as aldosterone-producing renin-responsive adenoma. Eleven patients had unilateral adrenalectomy and one preferred prolonged spironolactone therapy, resulting in a sustained cure or amelioration of hypertension, hypokalemia and normalization of aldosterone production.

Regulation of mineralocorticoid secretion by the superfused fetal monkey adrenal gland: lack of stimulation of aldosterone by ACTH.

The rhesus monkey fetal adrenal secretion of mineralocorticoids was studied in vitro. Superfusion of fetal adrenal minces (n = 6) demonstrated that the fetal adrenal secretes aldosterone as well as desoxycorticosterone, 18 hydroxydesoxy corticosterone, and 18 hydroxycorticosterone. Addition of 250 ng/ml ACTH to the superfusion medium did not result in stimulation of aldosterone, but did increase these other mineralocorticoids. These data indicate that aldosterone production is not readily stimulated by ACTH in the fetal rhesus monkey, although other steroids in the mineralocorticoid pathway are.