Individuals with type 2 diabetes have higher density of small intestinal neurotensin-expressing cells.

Neurotensin (NT) is a gastro-intestinal hormone involved in several pathways that regulate energy and glucose homeostasis. NT was hypothesized to act in synergy with incretin hormones to potentiate its anti-diabetic effects. Additionally, circulating NT levels were shown to rise after bariatric surgery-induced weight loss. Knowledge of NT-secreting cells distribution along the small intestine and its variation according to diabetes status could provide insights on NT role in mediating type 2 diabetes (T2D) improvement after bariatric surgery. So, our aims were to characterize NT-expressing cell distribution along the human small intestine and to compare the relative density of NT-expressing cells in the small intestine of individuals with and without T2D undergoing bariatric surgery for obesity treatment. Autopsy-derived small intestine fragments (n = 30) were obtained at every 20 cm along the entire intestinal length. Additionally, jejunum biopsies (n = 29) were obtained during elective gastric bypass interventions from patients with (n = 10) or without T2D (n = 18). NT-expressing cells were identified by immunohistochemistry and quantified via computerized morphometric analysis. NT-expressing cell density increased along the human small intestine. NT-expressing cell density was significantly higher from 200 cm distal to the duodenojejunal flexure onward, as well as in subjects with T2D when compared to those without T2D. NT-expressing cell density increases along the human small gut, and a higher density is found in individuals with T2D. This finding suggests a potential role for NT in the mechanisms of disease and T2D improvement observed after bariatric surgery.

Regular Voluntary Running is Associated with Increased Tumor Vascularization and Immune Cell Infiltration and Decreased Tumor Growth in Mice.

Tumors present dysfunctional vasculature that limits blood perfusion and hinders immune cells delivery. We aimed to investigate if regular voluntary running promotes tumor vascular remodelling, improves intratumoral immune cells infiltration and inhibits tumor growth. Tumors were induced in C57BL/6 male mice (n=28) by subcutaneous inoculation in the dorsal region with a suspension of RM1 cells (1.5×105 cells/500 µL PBS) and randomly allocated into two groups: sedentary (n=14) and voluntarily exercised on a wheel (n=14). Seven mice from each group were sacrificed 14 and 28 days after cells' inoculation to evaluate tumor weight, microvessel density, vessels' lumen regularity and the intratumoral quantity of NKG2D receptors, CD4+and CD8+T cells, by immunohistochemistry. The statistical inference was done through a two-way ANOVA. Exercised mice developed smaller tumors at 14 (0.17±0.1 g vs. 0.48±0.2 g, p<0.05) and 28 (0.92±0.7 g vs. 2.09±1.3 g, p<0.05) days, with higher microvessel density (21.20±3.2 vs. 15.86±4.0 vessels/field, p<0.05), more regular vessels' lumen (1.06±0.2 vs. 1.43±0.2, p<0.05), and higher CD8+T cells (464.95±48.0 vs. 364.70±49.4 cells/mm2, p<0.01), after 28 days. NKG2D expression was higher in exercised mice at 14 (263.27±25.8 cells/mm2, p<0.05) and 28 (295.06±56.2 cells/mm2, p<0.001) days. Regular voluntary running modulates tumor vasculature, increases immune cells infiltration and attenuates tumor growth, in mice.

Visceral Adipose Tissue Bioenergetics Varies According to Individuals' Obesity Class.

Obesity is associated with complex adipose tissue energy metabolism remodeling. Whether AT metabolic reprogramming differs according to body mass index (BMI) and across different obesity classes is unknown. This study's purpose was to evaluate and compare bioenergetics and energy substrate preference of visceral adipose tissue (VAT) pertaining to individuals with obesity class 2 and class 3. VAT obtained from patients with obesity (n = 15) class 2 (n = 7; BMI 37.53 ± 0.58 kg/m2) or class 3 (n = 8; BMI 47.79 ± 1.52 kg/m2) was used to assess oxygen consumption rate (OCR) bioenergetics and mitochondrial substrate preferences. VAT of patients with obesity class 3 presented significantly higher non-mitochondrial oxygen consumption (p < 0.05). In VAT of patients with obesity class 2, inhibition of pyruvate and glutamine metabolism significantly decreased maximal respiration and spare respiratory capacity (p < 0.05), while pyruvate and fatty acid metabolism inhibition, which renders glutamine the only available substrate, increased the proton leak with a protective role against oxidative stress (p < 0.05). In conclusion, VAT bioenergetics of patients with obesity class 2 depicts a greater dependence on glucose/pyruvate and glutamine metabolism, suggesting that patients within this BMI range are more likely to be responsive to interventions based on energetic substrate modulation for obesity treatment.

Ang-Tie Angiogenic Pathway Is Distinctively Expressed in Benign and Malignant Adrenocortical Tumors.

The differential diagnosis between adrenocortical adenomas (ACAs) and adrenocortical carcinomas (ACCs) relies on unspecific clinical, imaging and histological features, and, so far, no single molecular biomarker has proved to improve diagnostic accuracy. Similarly, prognostic factors have an insufficient capacity to predict the heterogeneity of ACC clinical outcomes, which consequently lead to inadequate treatment strategies. Angiogenesis is a biological process regulated by multiple signaling pathways, including VEGF and the Ang-Tie pathway. Many studies have stressed the importance of angiogenesis in cancer development and metastasis. In the present study, we evaluated the expression of VEGF and Ang-Tie pathway mediators in adrenocortical tumors (ACTs), with the ultimate goal of assessing whether these molecules could be useful biomarkers to improve diagnostic accuracy and/or prognosis prediction in ACC. The expression of the proteins involved in angiogenesis, namely CD34, VEGF, VEGF-R2, Ang1, Ang2, Tie1 and Tie2, was assessed by immunohistochemistry in ACC (n = 22), ACA with Cushing syndrome (n = 8) and non-functioning ACA (n = 13). ACC presented a significantly higher Ang1 and Ang2 expression when compared to ACA. Tie1 expression was higher in ACC with venous invasion and in patients with shorter overall survival. In conclusion, although none of these biomarkers showed to be useful for ACT diagnosis, the Ang-Tie pathway is active in ACT and may play a role in regulating ACT angiogenesis.

Regular Voluntary Running Inhibits Androgen-Independent Prostate Cancer Growth in Mice.

INTRODUCTION: Benefits of regular physical exercise were demonstrated as preventive and coadjuvant nonpharmacological anticancer therapy. However, the role of exercise in modulating prostate cancer behavior has yet to be established. METHODS: Prostate tumors were induced in C57BL/6 male mice (n = 28) by subcutaneous inoculation of a suspension of murine androgen-independent RM1 cells (1.5 × 105 cells/500 µL phosphate-buffered saline) in the dorsal region. Mice were randomly allocated into 2 study groups: sedentary tumor-induced (n = 14) and exercised tumor-induced (n = 14). Exercise consisted of voluntary running in wheeled cages. Mice (n = 7 per group) were sacrificed either 14 or 28 days after cell inoculation to evaluate tumor weight and percentage of area occupied by immunohistochemistry stained cells for Ki-67 and TdT-mediated dUTP-biotin nick end labeling, used as surrogate markers of cell proliferation and apoptosis, respectively. RESULTS: Compared with sedentary tumor-induced mice, the tumors developed by exercised tumor-induced mice were significantly smaller at 14 days (0.17 [0.12] g vs 0.48 [0.24] g, P < .05) and at 28 days (0.92 [0.73] g vs 2.09 [1.31] g, P < .05), with smaller Ki-67 and greater TdT-mediated dUTP-biotin nick end-labeling stained areas (P < .05). CONCLUSION: These results suggest that regular voluntary running inhibits prostate cancer cell growth by reducing cell proliferation and enhancing apoptosis.

Mineralocorticoid Receptor Antagonists Eplerenone and Spironolactone Modify Adrenal Cortex Morphology and Physiology.

Mineralocorticoid receptor antagonists (MRAs) are a class of anti-hypertensive drugs that act by blocking aldosterone action. The aim of this study was to evaluate whether the MRAs spironolactone and eplerenone influence adrenal cortical physiology and morphology. Spontaneous hypertensive rats (SHR, n = 18) and normotensive rats (WKY, n = 18) were randomly exposed to a daily dose of spironolactone (n = 6), eplerenone (n = 6), or no drug (n = 6) over 28 days. After that, aldosterone, corticosterone, and 11-deoxycorticosterone plasma concentrations were quantified. Adrenal glands were subjected to morphological analysis to assess lipid droplets content, capsular width, cell proliferation, and steroidogenic proteins expression. The adrenal cortex in untreated SHR showed higher lipid droplet content as than in WKY. In SHR, MRA treatment was associated with higher circulating aldosterone levels and Ki-67 expression in aldosterone-secreting cells. In WKY, the only difference observed after MRA spironolactone treatment was a narrower capsule. There was no difference in abundance of steroidogenic enzyme between groups. In conclusion, MRAs modify adrenal gland function and morphology in SHR. The effects observed within the adrenal glomerulosa with aldosterone-secreting cell proliferation and higher circulating aldosterone levels suggests that MRA treatment provokes activation of the renin angiotensin system. The prognostic value of hyperaldosteronism secondary to MRAs blockade requires further investigation.

Incomplete Pattern of Steroidogenic Protein Expression in Functioning Adrenocortical Carcinomas.

Autonomous steroid secretion is a common feature of adrenocortical carcinomas (ACC), although not always clinically evident owing to inefficient steroidogenesis with increased release of steroid precursors. Our study aim was to analyze the expression profile of four key proteins involved in the steroidogenesis cascade, in different adrenocortical tumors. Expression of proteins involved in steroidogenesis, namely steroidogenic acute regulatory protein (StAR), 11ß-hydroxylase (CYP11B1), aldosterone synthase (CYP11B2) and 17α-hydroxylase (CYP17A1), were analyzed by immunohistochemistry in ACC (n = 14), adenomas presenting with Cushing's syndrome (ACAc) (n = 11) and clinically non-functioning adenomas (ACAn) (n = 15). A percentage of the stained area for each protein was analyzed using ImageJ software for computerized morphometric quantification. CYP11B1, StAR and CYP17A1 expression were significantly lower in ACC when compared to ACAc. In addition, ACC presented co-staining cells for CYP11B1 and CYP11B2. CYP11B1 was the steroidogenic enzyme with the most discriminative power to distinguish ACC from ACAc, with a sensitivity of 100%, specificity of 92%, and an expression higher than 4.44%, indicating the presence of a cortisol secreting adenoma. ACC depicts an incomplete pattern of steroidogenic protein expression, with decreased CYP11B1 and CYP17A1, which could explain the predominant secretion of steroid precursors.

IGF2 role in adrenocortical carcinoma biology.

PURPOSE: Clinical outcomes of adrenocortical carcinomas (ACC) could be improved by using novel treatment targets based on the recent advances of tumor biology knowledge. Insulin-like growth factor 2 (IGF2) protein expression is usually 8-80 fold higher in ACC when compared to normal adrenal glands (N-AG) or adrenocortical adenomas (ACA), despite the fact that the biological features of high vs. low IGF2 expressing ACC have not yet been well characterized. Our goal was to understand the IGF2 role in ACC biology by focusing in several cancer hallmarks, including cell proliferation, viability, invasion, and metabolism. METHODS: IGF2 immunohistochemistry expression was evaluated in ACC (n = 13), non-functioning adrenocortical adenoma (ACAn) (n = 14), and N-AG (n = 9). The effects of IGF2 (50, 100 ng/mL) in cell proliferation, viability, invasion, and metabolism, as well as in MAPK/ERK and mTOR pathways activation and N-cadherin expression, were evaluated in the ACC human cell line H295R. RESULTS: IGF2 expression was increased in ACC compared to ACAn and N-AG. Exposure to 100 ng/mL of IGF2 increased H295R cell proliferation and viability. mTOR inhibition reverted IGF2 triggered cell proliferation and viability while MEK/MAPK/ERK inhibition only reverted IGF2 effects on cell proliferation. IGF2 at a 50 ng/mL concentration increased the glycolytic flux and decreased glutamine consumption. CONCLUSIONS: IGF2 is an excellent marker to differentiate ACC from ACAn. In addition, IGF2 was demonstrated to influence adrenocortical cancer cell proliferation, metabolism, and viability, but not the cell invasion. These data support that different IGF2 concentrations in ACC can be responsible for different biological behaviors of ACC.

Higher IL-6 peri-tumoural expression is associated with gastro-intestinal neuroendocrine tumour progression.

An association of well-differentiated gastroenteropancreatic neuroendocrine tumours (WD GEP NETs) with metabolic syndrome (MetS) was recently described. Yet no molecular mechanisms linking the two conditions are known. This study's aim was to identify putative molecular signatures linking WD GEP NETs and MetS to gain further insight into potential mechanisms for this association. Patients with WD GEP NETs (n=39), pancreatic (panNET) and gastro-intestinal (GI-NET), were clinically evaluated for presence of MetS. WD GEP NETs immunohistochemistry staining for Forkhead box protein M1 (FOXM1), insulin growth factor 1 receptor (IGF1R), Ki-67 and interleukin 6 (IL-6) was performed and quantified by computerised morphometric analysis. FOXM1, Ki-67, IGF1R or IL-6 expression in WD GEP NETs was not influenced by the presence of MetS. IL-6 peritumoural expression was higher in GI-NETs of patients with low HDL cholesterol (0.018±0.005% vs 0.030±0.005%, p=0.02). In GI-NETs, a higher IL-6 expression was also associated with disease progression (0.026±0.004% vs 0.016±0.002%, p=0.03). In WD GEP-NETs, MetS did not influence FOXM1, IGF1R and IL-6 expression. In GI-NETs, IL-6 expression was influenced by the MetS feature low HDL, and positively associated with disease progression. These data suggest that local and systemic inflammatory status can potentially modulate GI-NET behaviour.

MAPK/ERK pathway inhibition is a promising treatment target for adrenocortical tumors.

Unraveling molecular mechanisms that regulate tumor development and proliferation is of the utmost importance in the quest to decrease the high mortality rate of adrenocortical carcinomas (ACC). Our aim was to evaluate the role of two of the mitogen-activated protein kinase (MAPK) signaling pathways (extracellular signal-regulated protein kinases [ERKs 1/2] and p38) in the adrenocortical tumorigenesis, as well as the therapeutic potential of MAPK/ERK inhibition. ERKs 1/2 and p38 activation were evaluated in incidentalomas (INC; n = 10), benign Cushing's syndrome (BCS; n = 12), malignant Cushing's syndrome (MCS; n = 6) and normal adrenal glands (NAG; 8). ACC cell line (H295R) was used to evaluate the ability of PD184352 (0.1, 1, and 10 µM), a specific MEK-MAPK-ERK pathway inhibitor, to modulate cell proliferation, viability, metabolism, and steroidogenesis. ERKs 1/2 activation was significantly higher in MCS (2.83 ± 0.17) compared with NAG (1.00 ± 0.19 "arbitrary units"), INC (1.20 ± 0.13) and BCS (2.09 ± 0.09). Phospho-p38 expression was absent in all the MCS analyzed. MAPK/ERK kinase (MEK) inhibition with PD184352 significantly decreased proliferation as well as steroidogenesis and also increased the redox state of the H295R cells. This data suggests that MEK-MAPK-ERK signaling has a role in adrenocortical tumorigenesis that could be potentially used as a diagnostic marker for malignancy and targeted treatment in ACC.

Differential GIP/GLP-1 intestinal cell distribution in diabetics' yields distinctive rearrangements depending on Roux-en-Y biliopancreatic limb length.

As incretins are known to play an important role in type 2 diabetics (T2D) improvement observed after Roux-en-Y gastric bypass (RYGB), our aim was to assess whether increasing the length of RYGB biliopancreatic limb in T2D would modify the incretin staining cell density found after the gastric outlet. Small intestine biopsies (n = 38) were harvested during RYGB at two different distances from the duodenal angle; either 60-90 cm (n = 28), from non-diabetic (n = 18) patients, and T2D (n = 10), or 200 cm (n = 10) from T2D. GIP and GLP-1 staining cells were identified by immunohistochemistry and GLP-1/GIP co-staining cells by immunofluorescence. Incretin staining cell density at the proximal small intestine of T2D and non-diabetic individuals was similar. At 200 cm, T2D patients depicted a significantly lower GIP staining cell density (0.181 ± 0.016 vs 0.266 ± 0.033, P = 0.038) with a similar GLP-1 staining cell density when compared to the proximal gut. GIP/GLP-1 co-staining cells was similar in all studied groups. In T2D patients, the incretin staining cells density in the distal intestine is significantly different from the proximal gut. Thus, a longer RYGB biliopancreatic limb produces a distinctive incretin cell pattern at the gastro-enteric anastomosis that can result in different endocrine profiles.

Angiogenesis and Lymphangiogenesis in the Adrenocortical Tumors.

Adrenocortical tumors (ACT) are common adrenal tumors. The majority of ACTs are non-functioning and benign, while adrenocortical carcinomas (ACC) are rare, usually very aggressive and often metastasized when first diagnosed. Our aim was to assess whether blood and lymph vessel density within ACTs correlate with the malignancy character or tumor functionality. For that, the microvascular distribution was evaluated by immunohistochemistry staining with D2-40 antibody, for lymph vessels and CD-31 antibody, for blood vessels, in ACCs (n = 15), adenomas with Cushing syndrome (n = 9) and non-functioning adenomas (n = 10). The percentage of stained area was quantified by computerized morphometric analysis. D2-40 expression was significantly lower in ACC as compared to adenomas with Cushing syndrome (p < 0.01) and correlated positively with the expression of the steroidogenic acute regulatory protein (StAR) (R2 = 0.553, p < 0.001). CD31 expression was found to be significantly higher in ACC as compared to adenomas with Cushing syndrome (p < 0.05). Our results show that angiogenesis is increased in ACC, suggesting that this phenomenon may have an important role in ACT biological behavior, while lymph vascular density seems to be more closely related to the tumor functional status than malignancy.

Lymph Node Metastases in Papillary and Medullary Thyroid Carcinoma Are Independent of Intratumoral Lymphatic Vessel Density.

BACKGROUND: Blood and lymph vessel invasion are well-recognized markers of tumor aggressiveness, as these are the routes that lead to metastases. Thyroid tumors, depending on the histological variant, tend to have distinctive biological behaviors and use different vascular routes to metastasize, yet the mechanisms underlying the metastatic process are still poorly understood. OBJECTIVES: The aim of this study was to assess how the lymph vessel density (LVD) in different histological types of thyroid tumors, and in their surrounding tissue, correlate with the presence of lymph node metastases (LNM) and tumor pathological features. METHODS: Lymph vessels of papillary thyroid carcinomas (PTC), of the classical (CVPTC, n = 50) and follicular variants (FVPTC, n = 18), and medullary thyroid carcinomas (MTC, n = 34) were immunohistochemically stained against antigen D2-40. The stained area was quantified using a computerized morphometric analysis tool and correlated with the tumor pathological characteristics. RESULTS: LVD within all analyzed thyroid tumor subtypes was significantly lower than in the surrounding thyroid tissues (p < 0.001). Despite intratumoral LVD being significantly higher in CVPTC than in FVPTC, and peritumoral LVD being significantly higher in MTC than in PTC (p < 0.05), no correlations were found between LVD (either intratumoral or peritumoral) and the presence of lymph node metastasis. CONCLUSIONS: As no LVD differences were found amongst thyroid tumors with or without LNM, dissemination is more likely to depend on the tumor ability to invade the abundant lymph vessel network of the surrounding thyroid tissue than on the ability of the tumor to promote de novo lymphangiogenesis.

The emerging role of the molecular marker p27 in the differential diagnosis of adrenocortical tumors.

Malignant adrenocortical tumors (ACTs) are rare and highly aggressive; conversely, benign tumors are common and frequently found incidentally (the so-called incidentalomas). Currently, the use of molecular markers in the diagnosis of ACTs is still controversial. The aim of this study was to analyze the molecular profile of different ACTs with the purpose of identifying markers useful for differentiating between these tumors. The ACTs that were studied (n=31) included nonfunctioning adenomas (ACAn)/incidentalomas (n=13), functioning adenomas with Cushing's syndrome (ACAc) (n=7), and carcinomas (n=11); normal adrenal glands (n=12) were used as controls. For each sample, the percentage area stained for the markers StAR, IGF2, IGF1R, p53, MDM2, p21, p27, cyclin D1, Ki-67, ß-catenin, and E-cadherin was quantified using a morphometric computerized tool. IGF2, p27, cyclin D1, and Ki-67 were the markers for which the percentage of stained area was significantly higher in carcinoma samples than in adenoma samples. Ki-67 and p27 were the markers that exhibited the highest discriminative power for differential diagnosis between carcinomas and all type of adenomas, while IGF2 and StAR were only found to be useful for differentiating between carcinomas and ACAn and between carcinomas and ACAc respectively. The usefulness of Ki-67 has been recognized before in the differential diagnosis of malignant tumors. The additional use of p27 as an elective marker to distinguish benign ACTs from malignant ACTs should be considered.

Inflammatory granulocytes decrease subcutaneous growth of melanoma in mice.

Growing melanomas invade the subcutaneous tissues. We have compared the size of tumors implanted in the subcutaneous cavities of C57BL/6 mice where inflammatory reactions were induced before the injection of 5 x 10(5) melanoma cells (B16F10 cell line). Granulocytic inflammation of the subcutaneous cavities resulted in a significant decrease in the growth of the implanted melanomas, whereas monocytic inflammation had no effect on tumor growth. We conclude that granulocytes, but not monocytes/macrophages, have anti-tumor action on melanoma that invade the subcutaneous tissues.