👤 Aldo E Calogero

Congenital hypogonadotropic hypogonadism (CHH) is a rare and heterogeneous genetic disorder with variable penetrance caused by GnRH deficiency, leading to delayed puberty and infertility. In 50-60% of cases, CHH is associated with non-reproductive abnormalities, most commonly anosmia/hyposmia (Kallmann syndrome, KS). Over 60 genes have been implicated in CHH pathogenesis. We aimed to perform genetic screening in a cohort of 14 patients (10 males, 4 females; mean age 22 ± 7.72 years) with suspected or diagnosed HH/KS. Genetic analysis was conducted using next-generation sequencing (NGS) with a custom panel of 46 candidate genes. Variant interpretation followed ACMG standards and guidelines. Multiple tools were used to predict the structural effects of variants on tertiary protein structure, assessing their pathogenicity. Novel variants were functionally characterized by qRT-PCR on mRNA extracted from peripheral leukocytes. NGS identified nine rare variants and four novel variants in genes previously associated with normosmic isolated HH (nHH) and/or KS ( Show less

Congenital hypogonadotropic hypogonadism (cHH)/Kallmann syndrome (KS) is a rare genetic disorder with variable penetrance and a complex inheritance pattern. Consequently, it does not always follow Mendelian laws. More recently, digenic and oligogenic transmission has been recognized in 1.5-15% of cases. We report the results of a clinical and genetic investigation of five unrelated patients with cHH/KS analyzed using a customized gene panel. Patients were diagnosed according to the clinical, hormonal, and radiological criteria of the European Consensus Statement. DNA was analyzed using next-generation sequencing with a customized panel that included 31 genes. When available, first-degree relatives of the probands were also analyzed to assess genotype-phenotype segregation. The consequences of the identified variants on gene function were evaluated by analyzing the conservation of amino acids across species and by using molecular modeling. We found one new pathogenic variant of the Show less

Dual-specificity phosphatase 6 (DUSP6, mitogen-activated protein kinase (MAPK) phosphatase 3 or PYST1) dephosphorylates phosphotyrosine and phosphothreonine residues on extracellular signal-regulated kinase (ERK1/2; MAPK1/2) to inactivate the ERK1/2 kinase. DUSP6 is a critical regulator of the ERK signaling cascade and has been implicated as a tumor suppressor. We report here experimental evidences that DUSP6 is transcriptionally upregulated in primary and long-term cultures of human glioblastoma, as assayed by northern hybridization and real-time quantitative PCR, producing constitutive high level of protein expression. Functional assays were performed with adenovirus-mediated expression of DUSP6 in glioblastoma cultures. Protein overexpression inhibits growth by inducing G1-phase delay and increased mitogenic/anchorage dependence and clonogenic potential in vitro. Changes in cell morphology were associated with an increased tumor growth in vivo. Chemoresistance is a major cause of treatment failure and poor outcome in human glioblastomas. Importantly, DUSP6 overexpression increased resistance to cisplatin-mediated cell death in vitro and in vivo. Antisense-mediated depletion of DUSP6 acted in lowering the threshold to anticancer DNA-damaging drugs. We conclude that upregulation of DUSP6 exerts a tumor-promoting role in human glioblastomas exacerbating the malignant phenotype. Show less