Disease embryo development network reveals the relationship between disease genes and embryo development genes

A basic problem for contemporary biology and medicine is exploring the correlation between human disease and underlying cellular mechanisms. For a long time, several efforts were made to reveal the similarity between embryo development and disease process, but few from the system level. In this article, we used the human protein-protein interactions (PPIs), disease genes with their classifications and embryo development genes and reconstructed a human disease-embryo development network to investigate the relationship between disease genes and embryo development genes. We found that disease genes and embryo development genes are prone to connect with each other. Furthermore, diseases can be categorized into three groups according to the closeness with embryo development in gene overlapping, interacting pattern in PPI network and co-regulated by microRNAs or transcription factors. Embryo development high-related disease genes show their closeness with embryo development at least in three biological levels. But it is not for embryo development medium-related disease genes and embryo development low-related disease genes. We also found that embryo development high-related disease genes are more central than other disease genes in the human PPI network. In addition, the results show that embryo development high-related disease genes tend to be essential genes compared with other diseases' genes. This network-based approach could provide evidence for the intricate correlation between disease process and embryo development, and help to uncover potential mechanisms of human complex diseases.

miR-483-3p controls proliferation in wounded epithelial cells

The mechanisms that regulate keratinocyte migration and proliferation in wound healing remain largely unraveled, notably regarding possible involvements of microRNAs (miRNAs). Here we disclose up-regulation of miR-483-3p in 2 distinct models of wound healing: scratch-injured cultures of human keratinocytes and wounded skin in mice. miR-483-3p accumulation peaks at the final stage of the wound closure process, consistent with a role in the arrest of "healing" progression. Using an in vitro wound-healing model, videomicroscopy, and 5-bromo-2'-uridine incorporation, we observed that overexpression of miR-483-3p inhibits keratinocyte migration and proliferation, whereas delivery of anti-miR-483-3p oligonucleotides sustains keratinocyte proliferation beyond the closure of the wound, compared with irrelevant anti-miR treatment. Expression profiling of keratinocytes transfected with miR-483-3p identified 39 transcripts that were both predicted targets of miR-483-3p and down-regulated after miR-483-3p overexpression. Luciferase reporter assays, Western blot analyses, and silencing by specific siRNAs finally established that kinase MK2, cell proliferation marker MKI67, and transcription factor YAP1 are direct targets of miR-483-3p that control keratinocyte proliferation. miR-483-3p-mediated down-regulation of MK2, MKI67, and YAP1 thus represents a novel mechanism controlling keratinocyte growth arrest at the final steps of reepithelialization.

Toward a pathway-centered approach for the treatment of adrenocortical carcinoma

PURPOSE OF REVIEW

Adrenocortical carcinoma is an aggressive, lethal malignancy of the adrenal cortex. The rarity of the disease has stymied therapeutic development. Recent work toward understanding the molecular pathogenesis of the disease has identified several potential new diagnostic and therapeutic targets.

RECENT FINDINGS

The molecular characterization of adrenocortical carcinoma has identified dysregulation of the Gap 2/mitosis transition and the insulin-like growth factor 1 receptor signaling cascade as two major pathways for therapeutic development. These studies have also highlighted an unappreciated heterogeneity of the disease at the gene level that nevertheless seems to converge onto common cellular pathways. Additionally, the characterization of Wnt signaling through β-catenin in adrenal development, the demonstration of the involvement of BMP signaling in adrenocortical carcinoma growth regulation, and the discovery that ERCC1 expression levels can predict therapeutic response to platinum are just a few of the recent advances that promise to shed light on adrenocortical carcinoma biology.

SUMMARY

Short-term, therapeutic development should target the Gap 2/mitosis transition and the downstream signaling of the insulin-like growth factor 1 receptor receptor. Long-term, additional characterization of patient samples, particularly at the sequence level, is required to fully understand adrenocortical carcinoma biology and apply that knowledge to clinical practice.

mRNA and microRNA expression patterns in adrenocortical cancer

Adrenocortical cancer is a rare tumor and its prognosis is poor. Although numerous tumor-associated genetic and signal transduction alterations have been described to date, its pathogenesis is still unclear. Hybridization-based DNA microarray approaches may reveal significant gene expression alterations and may thus contribute to a better understanding of tumorigenesis and may identify molecular markers applicable for the distinction of benign and malignant lesions. Beside gene expression patterns, studies on microRNAs seem to be useful, as well. Novel therapeutical targets might be established by these approaches. In this review, the authors attempt to summarize the main findings of mRNA and microRNA expression microarray studies performed to date in adrenocortical cancer including a recent meta-analysis of gene expression data and present novel pathogenic pathways.

Genetics and genomics of childhood adrenocortical tumors

Adrenocortical tumors in children are usually diagnosed because of signs of virilization and their prognosis is poor. They possess several distinct pathological features compared to adrenocortical tumors in adults and have an exceptional prevalence in southern Brazil, where they are nearly invariably linked to the presence of a germline specific TP53 (R337H) mutation. Other important factors in childhood adrenocortical tumor pathogenesis are overexpression of the Steroidogenic Factor-1 transcription factor and imprinting defects in the 11p15 genomic region, causing overexpression of Insulin-like Growth Factor-2. Genomic studies have revealed the prognostic relevance of the expression of some Major Histocompatibility Complex genes and the deregulation of the Insulin-like Growth Factor/mammalian Target Of Rapamycin pathway by microRNAs in these tumors. Our hope is that these findings will constitute the basis for the development of novel therapies that will be more active against these tumors and less toxic for the patients.

MicroRNA-mediated downregulation of mTOR/FGFR3 controls tumor growth induced by Src-related oncogenic pathways

The tyrosine kinase c-Src is upregulated in various human cancers, but the molecular mechanisms underlying c-Src-mediated tumor growth remain unclear. Here we examined the involvement of microRNAs in the c-Src-mediated tumor growth. Microarray profiling revealed that c-Src activation downregulates a limited set of microRNAs, including miR-99a, which targets oncogenic mammalian target of rapamycin (mTOR) and fibroblast growth factor receptor 3 (FGFR3). Re-expression of miR-99a suppressed tumor growth of c-Src-transformed cells, and this effect was restored by the overexpression of mTOR. The downregulation of miR-99a was also observed in epidermal growth factor- and Ras-transformed cells, and it was suppressed by inhibiting the mitogen-activated protein kinase (MAPK) pathway. Furthermore, miR-99a downregulation is associated with mTOR/FGFR3 upregulation in various human lung cancer cells/tissues. The tumorigenicity of these cells was suppressed by the introduction of miR-99a. These findings suggest that the miR-99a-mTOR/FGFR3 pathway is crucial for controlling tumor growth in a wide range of human cancers that harbor upregulation of the Src-related oncogenic pathways.

The Wnt/beta-catenin pathway in adrenocortical development and cancer

Signaling by the Wnt family of secreted glycolipoproteins plays key roles in embryonic development of organisms ranging from nematodes to mammals and is also implicated in several types of human cancers. Canonical Wnt signaling functions by regulating the translocation of β-catenin to the nucleus, where it controls key gene expression programs through interaction with Tcf/Lef and other families of transcription factors. Wnts can also act through non-canonical pathways that do not involve β-catenin activation, but implicate small GTPases/JNK kinase and intracellular calcium. Here we review recent studies that have revealed the expression of several components of Wnt/β-catenin signaling in the adrenal cortex and discovered a key role for this pathway in the regulation of proliferation/differentiation of progenitor cells and in tumorigenesis of that endocrine organ.

Current and emerging therapies for advanced adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare but aggressive malignancy with a poor prognosis. Complete surgical resection offers the only potential for cure; however, even after apparently successful excision, local or metastatic recurrence is frequent. Treatment options for advanced ACC are severely limited. Mitotane is the only recognized adrenolytic therapy available; however, response rates are modest and unpredictable whereas systemic toxicities are significant. Reported responses to conventional cytotoxic chemotherapy have also been disappointing, and the rarity of ACC had hampered the ability to undertake randomized clinical studies until the establishment of the First International Randomized Trial in Locally Advanced and Metastatic Adrenocortical Carcinoma. This yet-to-be reported study seeks to identify the most effective first- and second-line cytotoxic regimens. The past decade has also seen increasing research into the molecular pathogenesis of ACCs, with particular interest in the insulin-like growth factor signaling pathway. The widespread development of small molecule tyrosine kinase inhibitors in broader oncological practice is now allowing for the rational selection of targeted therapies to study in ACC. In this review, we discuss the currently available therapeutic options for patients with advanced ACC and detail the molecular rationale behind, and clinical evidence for, novel and emerging therapies.

Potent inhibitory effect of the cyclolignan picropodophyllin (PPP) on human adrenocortical carcinoma cells proliferation

Adrenocortical carcinoma (ACC) is a very aggressive tumor with a poor prognosis. Available treatments for this type of cancer are far from being satisfactory. The IGF signalling pathway represents an important mechanism for ACT growth and constitutes a relevant therapeutic target. We investigated the effect of picropodophyllin (PPP), a member of the cyclolignan family and a new inhibitor of IGF-1R, on proliferation of human adrenocortical cell lines H295R and SW-13. PPP inhibits proliferation and induces an important accumulation in G2/M phase and apoptosis of H295R and SW-13 cells. Our data suggest that PPP may be a promising candidate for drug development for adrenocortical carcinoma.

Clinical characteristics of adrenocortical tumors in children

BACKGROUND

Adrenocortical tumors (ACTs) are rare in children. Because of the rarity and various manifestations of ACTs, patients of ACTs are not easily diagnosed. Some patients were misdiagnosed before surgery.

OBJECTIVE

Identify the clinical, laboratorial, imaging and histopathological characteristics of adrenocortical tumors in children. Compare adrenalcortical adenoma with carcinoma.

METHODS

A retrospective review of 34 identified patients who were younger than 15 years old with histologic confirmation of adrenocortical carcinoma (ACC) or adenomas from 1991 to 2010.

RESULTS

In these 34 patients, 19 were adrenocortical adenoma (ACA) and 15 were ACC. The median age at diagnosis was 3.33 years (range, 0-16 years), and 70.6% of the patients were younger than five years. Girls slightly predominated over boys (1.4:1). For endocrine abnormality, 14 patients had isolated precocious puberty, five patients had isolated Cushing syndrome, 10 patients had precocious puberty plus Cushing syndrome, and five patients did not have any symptoms. The most frequent findings in laboratory tests were disturbance of the normal circadian rhythm of cortisol secretion (93.8%), followed by elevated serum level of testosterone (89.7%). Only 3.8% of ultrasound diagnosis and 12.1% of computed tomography (CT) diagnosis were consistent with pathologic diagnosis.

CONCLUSION

Different from those in adult, the most frequent presentation in children with ACTs is peripheral precocious puberty with or without Cushing syndrome, and isolated Cushing syndrome. Few present with non-functional local mass. Laboratory tests usually reveal the discordantly elevated serum levels of sexual corticosteroid hormones, change of diurnal rhythm of cortisol or increase of morning cortisol. The differentiation of malignant from benign tumor cannot merely depend on imaging. Final diagnosis relies on comprehensive evaluation of clinical manifestations, laboratory data, imaging and pathology.

ChIP-on-chip analysis reveals angiopoietin 2 (Ang2, ANGPT2) as a novel target of steroidogenic factor-1 (SF-1, NR5A1) in the human adrenal gland

The nuclear receptor steroidogenic factor-1 (SF-1, NR5A1) is a key regulator of adrenal and gonadal biology. Disruption of SF-1 can lead to disorders of adrenal development, while increased SF-1 dosage has been associated with adrenocortical tumorigenesis. We aimed to identify a novel subset of SF-1 target genes in the adrenal by using chromatin immunoprecipitation (ChIP) microarrays (ChIP-on-chip) combined with systems analysis. SF-1 ChIP-on-chip was performed in NCI-H295R human adrenocortical cells using promoter tiling arrays, leading to the identification of 445 gene loci where SF-1-binding regions were located from 10 kb upstream to 3 kb downstream of a transcriptional start. Network analysis of genes identified as putative SF-1 targets revealed enrichment for angiogenic process networks. A 1.1-kb SF-1-binding region was identified in the angiopoietin 2 (Ang2, ANGPT2) promoter in a highly repetitive region, and SF-1-dependent activation was confirmed in luciferase assays. Angiogenesis is paramount in adrenal development and tumorigenesis, but until now a direct link between SF-1 and vascular remodeling has not been established. We have identified Ang2 as a potentially important novel target of SF-1 in the adrenal gland, indicating that regulation of angiogenesis might be an important additional mechanism by which SF-1 exerts its actions in the adrenal gland.—Ferraz-de-Souza, B., Lin, L., Shah, S., Jina, N., Hubank, M., Dattani, M. T., Achermann, J. C. ChIP-on-chip analysis reveals angiopoietin 2 (Ang2, ANGPT2) as a novel target of steroidogenic factor-1 (SF-1, NR5A1) in the human adrenal gland.

Therapy of adrenocortical cancer: present and future

Adrenocortical carcinoma is a rare endocrine malignancy with an estimated worldwide incidence of 0.5 - 2 per million/year. This neoplasm is characterized by a high risk of recurrence and a dismal prognosis owing to unsatisfactory overall survival. Surgery represents the cornerstone of adrenocortical carcinoma therapy, which can be associated to radiotherapy and adjuvant mitotane administration. In advanced cases, different chemotherapy regimens are used, but their relative efficacy is still unknown until the results of clinical trials under way will be published. Novel drugs have been recently developed based on the discovery of molecular pathways that trigger development and evolution of these tumors. More efficient treatments are widely expected in the future from these new targeted therapies as a hope of cure for patients affected with this aggressive malignancy.

MicroRNA profiling of adrenocortical tumors reveals miR-483 as a marker of malignancy

BACKGROUND

The authors are interested in identifying molecular markers that can aid in the diagnosis of adrenocortical carcinoma (ACC). The aim of this study was to identify microRNAs (miRNAs or miRs) that are differentially expressed in malignant adrenocortical tumors as compared with benign tumors and assess their potential as diagnostic predictors.

METHODS

Differentially expressed miRNAs were identified using microarray profiling of adrenocortical tumors and validated by quantitative real-time RT-PCR.

RESULTS

Microarray profiling in benign and primary malignant adrenocortical tumors revealed several significant differences between these histological groups. By using directed quantitative RT-PCR analysis on a subset of these differentially expressed miRNAs, the authors determined that miRs -100, -125b, and -195 were significantly down-regulated, whereas miR-483-5p was significantly up-regulated in malignant as compared with benign tumors. Furthermore, the current study shows that miR-483-5p expression can accurately categorize tumors as benign or malignant.

CONCLUSIONS

The authors identified 4 miRNAs that are dysregulated in adrenocortical carcinoma. The high expression of one of these, miR-483-5p, appears to be a defining characteristic of adrenocortical malignancies, and can thus be used to accurately distinguish between benign and malignant adrenocortical tumors.

Roles of host and viral microRNAs in human cytomegalovirus biology

Human cytomegalovirus (HCMV) has a relatively large and complex genome, a protracted lytic replication cycle, and employs a strategy of replicational latency as part of its lifelong persistence in the infected host. An important form of gene regulation in plants and animals revolves around a type of small RNA known as microRNA (miRNA). miRNAs can serve as major regulators of key developmental pathways, as well as provide subtle forms of regulatory control. The human genome encodes over 900 miRNAs, and miRNAs are also encoded by some viruses, including HCMV, which encodes at least 14 miRNAs. Some of the HCMV miRNAs are known to target both viral and cellular genes, including important immunomodulators. In addition to expressing their own miRNAs, infections with some viruses, including HCMV, can result in changes in the expression of cellular miRNAs that benefit virus replication. In this review, we summarize the connections between miRNAs and HCMV biology. We describe the nature of miRNA genes, miRNA biogenesis and modes of action, methods for studying miRNAs, HCMV-encoded miRNAs, effects of HCMV infection on cellular miRNA expression, roles of miRNAs in HCMV biology, and possible HCMV-related diagnostic and therapeutic applications of miRNAs.