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

Cellular Senescence in Adrenocortical Biology and Its Disorders

Cellular senescence is considered a physiological process along with aging and has recently been reported to be involved in the pathogenesis of many age-related disorders. Cellular senescence was first found in human fibroblasts and gradually explored in many other organs, including endocrine organs. The adrenal cortex is essential for the maintenance of blood volume, carbohydrate metabolism, reaction to stress and the development of sexual characteristics. Recently, the adrenal cortex was reported to harbor some obvious age-dependent features. For instance, the circulating levels of aldosterone and adrenal androgen gradually descend, whereas those of cortisol increase with aging. The detailed mechanisms have remained unknown, but cellular senescence was considered to play an essential role in age-related changes of the adrenal cortex. Recent studies have demonstrated that the senescent phenotype of zona glomerulosa (ZG) acts in association with reduced aldosterone production in both physiological and pathological aldosterone-producing cells, whereas senescent cortical-producing cells seemed not to have a suppressed cortisol-producing ability. In addition, accumulated lipofuscin formation, telomere shortening and cellular atrophy in zona reticularis cells during aging may account for the age-dependent decline in adrenal androgen levels. In adrenocortical disorders, including both aldosterone-producing adenoma (APA) and cortisol-producing adenoma (CPA), different cellular subtypes of tumor cells presented divergent senescent phenotypes, whereby compact cells in both APA and CPA harbored more senescent phenotypes than clear cells. Autonomous cortisol production from CPA reinforced a local cellular senescence that was more severe than that in APA. Adrenocortical carcinoma (ACC) was also reported to harbor oncogene-induced senescence, which compensatorily follows carcinogenesis and tumor progress. Adrenocortical steroids can induce not only a local senescence but also a periphery senescence in many other tissues. Therefore, herein, we systemically review the recent advances related to cellular senescence in adrenocortical biology and its associated disorders.

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.

The Role of Immunohistochemical Markers for the Diagnosis and Prognosis of Adrenocortical Neoplasms

Adrenal cortical carcinoma (ACC) is a rare cancer with poor prognosis that needs to be distinguished from adrenocortical adenomas (ACAs). Although, the recently developed transcriptome analysis seems to be a reliable tool for the differential diagnosis of adrenocortical neoplasms, it is not widely available in clinical practice. We aim to evaluate histological and immunohistochemical markers for the distinction of ACCs from ACAs along with assessing their prognostic role. Clinical data were retrospectively analyzed from 37 patients; 24 archived, formalin-fixed, and paraffin-embedded ACC samples underwent histochemical analysis of reticulin and immunohistochemical analysis of p27, p53, Ki-67 markers and were compared with 13 ACA samples. Weiss and Helsinki scores were also considered. Kaplan-Meier and univariate Cox regression methods were implemented to identify prognostic effects. Altered reticulin pattern, Ki-67% labelling index and overexpression of p53 protein were found to be useful histopathological markers for distinguishing ACAs from ACCs. Among the studied markers, only pathological p53 nuclear protein expression was found to reach statistically significant association with poor survival and development of metastases, although in a small series of patients. In conclusion, altered reticulin pattern and p53/Ki-67 expression are useful markers for distinguishing ACCs from ACAs. Immunohistopathology alone cannot discriminate ACCs with different prognosis and it should be combined with morphological criteria and transcriptome analysis.

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), 11β-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.

Fusobacterium nucleatum Caused DNA Damage and Promoted Cell Proliferation by the Ku70/p53 Pathway in Oral Cancer Cells

Bacterial infection influences genomic stability and integrity by causing DNA damage, which increases the possibility of tumor initiation and development. We aimed to investigate whether Fusobacterium nucleatum, one of the periodontal pathogens, promoted oral squamous cell carcinoma (OSCC) by causing DNA double-strand break (DSB). Tca8113 tongue squamous cell carcinoma cells were infected with F. nucleatum. The expression of γH2AX was detected by western blots and immunofluorescence. The proliferation and cell cycle alterations were tested by CCK8 and flow cytometry, respectively. The expression levels of Ku70, p53, and p27 were evaluated by quantitative real-time polymerase chain reaction and western blots. A plasmid was used for the overexpression of Ku70 to verify the possible relationship between Ku70 and p53. We confirmed the presence of DSBs in the response to F. nucleatum by detecting the expression of γH2AX. The cell proliferation ability was increased with an accelerated cell cycle while the expression of p27 was decreased. Meanwhile, the expression of Ku70 and wild p53 was downregulated. When Ku70 was overexpressed, the expression of wild p53 in response to F. nucleatum infection was upregulated and cell proliferation was accordingly inhibited. We concluded that F. nucleatum infection promoted the proliferation ability of Tca8113 by causing DNA damage via the Ku70/p53 pathway.

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.

Apoptosis regulation in adrenocortical carcinoma

Apoptosis evading is a hallmark of cancer. Tumor cells are characterized by having an impaired apoptosis signaling, a fact that deregulates the balance between cell death and survival, leading to tumor development, invasion and resistance to treatment. In general, patients with adrenocortical carcinomas (ACC) have an extremely bad prognosis, which is related to disease progression and significant resistance to treatments. In this report, we performed an integrative review about the disruption of apoptosis in ACC that may underlie the characteristic poor prognosis in these patients. Although the apoptosis has been scarcely studied in ACC, the majority of the deregulation phenomena already described are anti-apoptotic. Most importantly, in a near future, targeting apoptosis modulation in ACC patients may become a promising therapeutic.

Acute effect of an amino acid mixture in the rat glycemic profile

Amino acid mixtures (AAM) are protein substitutes used for phenylketonuria treatment, but their metabolic effects have not been well characterized. The objective of this study was to compare the acute glycemic response to free amino acids (free AA) from AAM with the response to intact protein (iProtein). Male Wistar rats (n = 14) were administered by gavage a bolus of free AA (n = 7) or iProtein as albumin (n = 7) containing equivalent amounts of nitrogen. Blood glucose and insulin levels were measured at baseline and 15, 30, 60 and 120 minutes later, when gut GLP-1 content and pancreatic insulin, GLP-1 receptor and Ki67 expression were quantified at 120 minutes time point. After AAM, glucose area under the curve (free AA vs iProtein; P < 0.01), serum insulin levels at 120 minutes (free AA vs iProtein; P < 0.05), colon GLP-1 content (free AA vs iProtein; P < 0.01), pancreatic GLP-1 receptor (free AA vs iProtein; P < 0.01) and insulin expression (free AA vs iProtein; p < 0.01) were significantly lower as compared with iProtein. AAM increased Ki67 expression in pancreatic islets (free AA vs iProtein; P < 0.05). In conclusion, this study demonstrated that acute response to AAM differs from iProtein and is characterized by a lower glucose excursion, along with a decrease in gut GLP-1 and pancreatic GLP-1 receptor and insulin. This data suggests the modulation of glycemia by free AA is mediated by the incretin axis.

MECHANISMS OF ENDOCRINOLOGY: Cell cycle regulation in adrenocortical carcinoma

Adrenocortical carcinomas (ACCs) are rather rare endocrine tumors that often have a poor prognosis. The reduced survival rate associated with these tumors is due to their aggressive biological behavior, combined with the scarcity of effective treatment options that are currently available. The recent identification of the genomic alterations present in ACC have provided further molecular mechanisms to develop consistent strategies for the diagnosis, prevention of progression and treatment of advanced ACCs. Taken together, molecular and genomic advances could be leading the way to develop personalized medicine in ACCs similarly to similar developments in lung or breast cancers. In this review, we focused our attention to systematically compile and summarize the alterations in the cell cycle regulation that were described so far in ACC as they are known to play a crucial role in cell differentiation and growth. We have divided the analysis according to the major transition phases of the cell cycle, G1 to S and G2 to M. We have analyzed the most extensively studied checkpoints: the p53/Rb1 pathway, CDC2/cyclin B and topoisomerases (TOPs). We reached the conclusion that the most important alterations having a potential application in clinical practice are the ones related to p53/Rb1 and TOP 2. We also present a brief description of on-going clinical trials based on molecular alterations in ACC. The drugs have targeted the insulin-like growth factor receptor 1, TOP 2, polo-like kinase1, cyclin-dependent kinase inhibitors, p53 reactivation and CDC25.

Immunohistochemical Biomarkers of Adrenal Cortical Neoplasms

Careful morphological evaluation forms the basis of the workup of an adrenal cortical neoplasm. However, the adoption of immunohistochemical biomarkers has added tremendous value to enhance diagnostic accuracy. The authors provide a brief review of immunohistochemical biomarkers that have been used in the confirmation of adrenal cortical origin and in the detection of the source of functional adrenal cortical proliferations, as well as diagnostic, predictive, and prognostic biomarkers of adrenal cortical carcinoma. In addition, a brief section on potential novel theranostic biomarkers in the prediction of treatment response to mitotane and other relevant chemotherapeutic agents is also provided. In the era of precision and personalized medical practice, adoption of combined morphology and immunohistochemistry provides a new approach to the diagnostic workup of adrenal cortical neoplasms, reflecting the evolution of clinical responsibility of pathologists.

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.

Telomerase and N-Cadherin Differential Importance in Adrenocortical Cancers and Adenomas

Adrenocortical carcinomas (ACC) are most frequently highly aggressive tumors. We assessed the telomerase reverse transcriptase (TERT) and N-cadherin role in the biology of ACC and their potential utility as molecular biomarkers, in different types of tumoral adrenocortical tissue. A total of 48 adrenal cortex samples (39 tumoral and 9 normal adrenal glands) were studied. TERT promoter mutations were searched by PCR and Sanger sequencing in two hotspots positions (-124 and -146). Also, telomerase and N-cadherin expression were evaluated by immunohistochemistry. TERT promoter mutations were not detected in any of the samples either malignant or benign. Telomerase nuclear expression was present in 26.6% of ACC and in 45.5% of non-functioning adenomas. It was absent in benign Cushing's lesions and in normal adrenal glands. Contrarily, N-cadherin was always expressed in the cellular membranes of benign adenomas or normal adrenals but no expression was detected in the majority of ACC. Nuclear telomerase and membrane N-cadherin expression were positively correlated in ACCs. We conclude that in ACC, the loss of N-cadherin is a frequent phenomenon while the existence of TERT promoter mutations is not and nuclear telomerase expression is present in only a minority of cases. Since the loss of N-cadherin expression was identified in both high and low proliferative ACC, this marker should be considered important for diagnostic application. Our study also suggests the existence of a TERT non-canonical function in cell adhesion. J. Cell. Biochem. 118: 2064-2071, 2017. © 2017 Wiley Periodicals, Inc.

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.

Insulin-like growth factor--phosphatidylinositol 3 kinase signaling in canine cortisol-secreting adrenocortical tumors

Background

Hypercortisolism is a common endocrine disorder in dogs, caused by a cortisol‐secreting adrenocortical tumor (AT) in approximately 15% of cases. In adrenocortical carcinomas of humans, activation of the phosphatidylinositol 3 kinase (PI3K) signaling pathway by insulin‐like growth factor (IGF) signaling represents a promising therapeutic target.

Objectives

To investigate the involvement of PI3K signaling in the pathogenesis of ATs in dogs and to identify pathway components that may hold promise as future therapeutic targets or as prognostic markers.

Animals

Analyses were performed on 36 canine cortisol‐secreting ATs (11 adenomas and 25 carcinomas) and 15 normal adrenal glands of dogs.

Methods

mRNA expression analysis was performed for PI3K target genes, PI3K inhibitor phosphatase and tensin homolog (PTEN), IGFs, IGF receptors, IGF binding proteins and epidermal growth factor receptors. Mutation analysis was performed on genes encoding PTEN and PI3K catalytic subunit (PIK3CA).

Results

Target gene expression indicated PI3K activation in carcinomas, but not in adenomas. No amino acid‐changing mutations were detected in PTEN or PIK3CA and no significant alterations in IGF‐II or IGFR1 expression were detected. In carcinomas, ERBB2 expression tended to be higher than in normal adrenal glands, and higher expression of inhibitor of differentiation 1 and 2 (ID1 and ID2) was detected in carcinomas with recurrence within 2.5 years after adrenalectomy.

Conclusions and Clinical Importance

Based on these results, ERBB2 might be a promising therapeutic target in ATs in dogs, whereas ID1 and 2 might be valuable as prognostic markers and therapeutic targets.

Immune response in the adipose tissue of lean mice infected with the protozoan parasite Neospora caninum

The adipose tissue can make important contributions to immune function. Nevertheless, only a limited number of reports have investigated in lean hosts the immune response elicited in this tissue upon infection. Previous studies suggested that the intracellular protozoan Neospora caninum might affect adipose tissue physiology. Therefore, we investigated in mice challenged with this protozoan if immune cell populations within adipose tissue of different anatomical locations could be differently affected. Early in infection, parasites were detected in the adipose tissue and by 7 days of infection increased numbers of macrophages, regulatory T (Treg) cells and T-bet(+) cells were observed in gonadal, mesenteric, omental and subcutaneous adipose tissue. Increased expression of interferon-γ was also detected in gonadal adipose tissue of infected mice. Two months after infection, parasite DNA was no longer detected in these tissues, but T helper type 1 (Th1) cell numbers remained above control levels in the infected mice. Moreover, the Th1/Treg cell ratio was higher than that of controls in the mesenteric and subcutaneous adipose tissue. Interestingly, chronically infected mice presented a marked increase of serum leptin, a molecule that plays a role in energy balance regulation as well as in promoting Th1-type immune responses. Altogether, we show that an apicomplexa parasitic infection influences immune cellular composition of adipose tissue throughout the body as well as adipokine production, still noticed at a chronic phase of infection when parasites were already cleared from that particular tissue. This strengthens the emerging view that infections can have long-term consequences for the physiology of adipose tissue.

Expression of p27 and PTEN and clinical characteristics in early laryngeal squamous cell carcinoma and their correlation with recurrence

Laryngeal squamous cell carcinoma is a common malignant tumor of otolaryngeal region. At present, effective treatment of laryngeal squamous cell carcinoma still depends on surgery and radiotherapy. In recent years, application of CO2 laser resection in the treatment of stage T1 glottic carcinoma can remove the tumor completely and reduce the injury of laryngeal tissues. But recurrence still happened in some postoperative patients. Here, we selected 131 patients to compare the therapeutic effects of CO2 laser resection and traditional split laryngeal surgery on the early laryngeal cancer, examined the expression of p27 and PTEN by immunohistochemistry in early laryngeal squamous cell carcinoma tissues in correlation to clinical outcome. After two years follow-up 14/85 (16.5%) of CO2 laser treatment group presented with local recurrence (recurrent group), while that of split laryngeal surgery group was 6/46 (13.0%). There was no statistical significance in recurrence rate between the two groups (P>0.05). 10 of all the 111 (9.0%) non-recurrent patients did not follow the doctor's advice to quit smoking after the operation, while 12 in the 20 (60.0%) recurrent patients did not; the difference between the two groups was statistically significant (P<0.01). The positive rates of p27 were 80.2% (105/131) and 43.5% (57/131), and that of PTEN were 83.2% (109/131) and 48.9% (64/131) in the cancer adjacent tissues (negative surgical margin tissues) and in laryngeal carcinoma tissues, respectively (P<0.001). The expression rates of p27 and PTEN in laryngeal carcinoma tissues of the recurrent group were 20.0% (4/20), 10.0% (2/20) and that in non recurrent group were 47.7% (53/111) and 55.9% (62/111), respectively, with a significant difference (P<0.001). In addition, the expression of p27 and PTEN in tumor resected marginal tissues of the recurrence group was 50.0% (10/20), 40.0% (8/20) and that in non recurrence group was 85.6% (95/111) and 91.0% (101/111), respectively; the difference was also statistically significant between both groups (P<0.001). In conclusion, there is no statistically significant difference in tumor recurrence rate between CO2 laser surgery and traditional split laryngeal surgery. Postoperative recurrence is closely related to resume smoking. The recurrence rate of p27 and/or PTEN-negative patients was higher than that of the positive ones,that should be followed up closely after treatment.