Amplification of the insulin-like growth factor 1 receptor gene is a rare event in adrenocortical adenocarcinomas: searching for potential mechanisms of overexpression

MicroRNA dysregulation interplay with childhood abdominal tumors

Abdominal tumors (AT) in children account for approximately 17% of all pediatric solid tumor cases, and frequently exhibit embryonal histological features that differentiate them from adult cancers. Current molecular approaches have greatly improved the understanding of the distinctive pathology of each tumor type and enabled the characterization of novel tumor biomarkers. As seen in abdominal adult tumors, microRNAs (miRNAs) have been increasingly implicated in either the initiation or progression of childhood cancer. Moreover, besides predicting patient prognosis, they represent valuable diagnostic tools that may also assist the surveillance of tumor behavior and treatment response, as well as the identification of the primary metastatic sites. Thus, the present study was undertaken to compile up-to-date information regarding the role of dysregulated miRNAs in the most common histological variants of AT, including neuroblastoma, nephroblastoma, hepatoblastoma, hepatocarcinoma, and adrenal tumors. Additionally, the clinical implications of dysregulated miRNAs as potential diagnostic tools or indicators of prognosis were evaluated.

Non-Coding RNAs in Adrenocortical Cancer: From Pathogenesis to Diagnosis

Non-coding RNA molecules including microRNAs and long non-coding RNAs (lncRNA) have been implicated in the pathogenesis of several tumors and numerous data support their applicability in diagnosis as well. Despite recent advances, the pathogenesis of adrenocortical cancer still remains elusive and there are no reliable blood-borne markers of adrenocortical malignancy, either. Several findings show the potential applicability of microRNAs as biomarkers of malignancy and prognosis, and there are some data on lncRNA as well. In this review, we present a synopsis on the potential relevance of non-coding RNA molecules in adrenocortical pathogenesis and their applicability in diagnosis from tissue and blood.

SIRT6 abrogation promotes adrenocortical carcinoma through activation of NF-κB signaling

As an uncommon malignancy in the adrenal gland, adrenocortical carcinoma (ACC) is characterized by thorny diagnosis and poor clinical outcome, necessitating innovative treatment strategies. Sirtuin 6 (SIRT6), a tumor suppressor, modulates aerobic glycolysis of malignant cells and has an impact on tumorigenesis. This study focused on investigating SIRT6 expression in ACC and how it generates cancer phenotypes. SIRT6 expression was inhibited in ACC tissues according to western blotting, real-time polymerase chain reaction, and immunohistochemistry. MTT assay, TUNEL assay, and flow cytometry were performed to evaluate the contribution of SIRT6 to cell invasion, proliferation, death, and migration. It was shown that SIRT6 knockdown promoted cell invasion, proliferation, and migration, and inhibited cell death. Moreover, it was found that SIRT6 knockdown upregulated TLR4 and reinforced phosphorylation of the nuclear transcription factor-kappa B (NF-κB) subunit p65 as well as inhibitor of nuclear factor kappa-B kinase. Additionally, SIRT6 knockdown significantly enhanced expression of calcitonin gene-related peptide as well as transient receptor potential vanilloid subtype 1. It also reinforced reactive oxygen species generation. Overall, our research findings demonstrate that SIRT6 serves as a tumor suppressor via regulation of the NF-κB pathway, which could offer an innovative strategy to treat ACC.

Targeting IGF1R pathway in cancer with microRNAs: How close are we?

Cancer of the head and neck are the most common cancers in India and account for 30% of all cancers. At molecular level, it could be attributed to the overexpression of growth factors like IGF1-R, EGFR, VEGF-R and deregulation of cell cycle regulators and tumor suppressors. IGF1-R is an emerging target in head and neck cancer treatment, because of its reported role in tumor development, progression and metastasis. IGF1R targeted agents are in advanced stages of clinical development. Nevertheless, these agents suffer from several disadvantages including acquired resistance and toxic side effects. Hence there is a need for developing newer agents targeting not only the receptor but also its downstream signaling. miRNAs are considered as master regulators of gene expression of multiple genes and has been widely reported to be a promising therapeutic strategy. This review discusses the present status of research in both these arenas and emphasizes the role of miRNA as a promising agent for biologic therapy.

Relationship between insulin-like growth factor axis gene polymorphisms and clinical outcome in advanced gastric cancer patients treated with FOLFOX

The insulin-like growth factor (IGF) axis plays a crucial role in proliferation, differentiation, migration, angiogenesis, and apoptosis. The present study evaluated the associations between IGF axis single-nucleotide polymorphisms (SNPs) and clinical outcomes in advanced gastric cancer (AGC) patients treated with oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX). A total of 190 patients undergoing FOLFOX chemotherapy for AGC were considered eligible for this study. Forty-four SNPs of 10 IGF axis genes were genotyped. Levels of serum IGF1 were measured using enzyme-linked immunoassays. SNPs of the IGF1R (rs12423791), and IGF1 (rs2162679, rs5742612, rs35767) genes were significantly associated with tumor response to FOLFOX. SNPs of rs4619 and rs17847203 were significantly associated with PFS (hazard ratio [HR] 0.575, 95% CI 0.385–0.858, P = 0.007; and HR 2.530, 95% CI 1.289–4.966, P = 0.007; respectively). SNPs of rs2872060 were significantly associated with OS—OS was shorter in patients carrying the TT variant than in those with the GG/GT genotypes (HR, 1.708, 95% CI 1.024–2.850, P = 0.040). The GT genotype of rs12847203 was also identified as an independent prognostic factor (HR 2.087, 95% CI 1.070–4.069, P = 0.031). These results suggest that IGF axis-pathway SNPs could be used as prognostic biomarkers of the outcome of FOLFOX chemotherapy in AGC patients. This information may facilitate identification of population subgroups that could benefit from IGF1R-targeted agents.

Pediatric adrenal cortical carcinomas: Histopathological criteria and clinical trials. A systematic review

Adrenal tumors are quite rare in infancy and childhood with the exception of neuroblastoma. In fact, adrenocortical tumors (ACT) account for only 0.2% of all malignant cancers in children and adolescents. According to a multicenter registry investigation, the median interval between first endocrine symptoms and the diagnosis of ACT is 5months, and death is seen in 38% of patients, who suffer from tumor progression following the diagnosis in about 2½years. The prognosis of pediatric ACC is poor with a 5-year event-free survival of 54%. To face this dreadful scenario, a few decades ago the International Pediatric Adrenocortical Tumor Registry (IPACTR) was established. Moreover, Children's Oncology Group (COG) and National Cancer Institute (NCI) have approved several clinical trials designed to investigate new treatment options in pediatric ACT. In this systematic review, we summarize the diagnostic histopathologic criteria, bio-markers, and clinical trials of this challenging diagnosis. Eleven pediatric ACT trials were reviewed in our investigation. Two out of 11 studies were conducted in Brazil showing apparently an increased rate of germline mutation-related pediatric ACT. A heterogeneous methodology was evident with four non-randomized clinical trials, three prospective cohort studies, and four retrospective case-control studies limiting higher statistical approach. Tumor histology remains the backbone to diagnose ACT creating a common investigative platform and potentially supporting studies aiming to increase international collaborative research, which is crucial for this challenging disease.