Giuseppe Damante

Purpose: To uncover underlying mutations in a cohort of Italian patients with aniridia, a rare congenital panocular condition with an incidence ranging from 1:64,000 to 1:100,000. The disease may be found isolated or in association with other syndromes characterized by partial or complete absence of the iris and iris hypoplasia. Methods: We analyzed the PAX6 gene in 11 patients with aniridia fulfilling the following inclusion criteria: partial or complete absence of the iris and age < 18 years at the time of diagnosis. DNA sequence analysis was integrated with Multiple Ligation Probe Assay (MLPA) analysis. Results: We identified seven PAX6 mutations, including four novel ones. The majority of mutations lie in the DNA-binding domain and all produce a truncated protein. All tested patients did not have WT1 gene deletions thus excluding the WAGR syndrome. We present the clinical findings in the four cases harboring novel mutations. We were unable to identify mutations in four cases with complete aniridia thus indicating that other gene/s could be involved in the disease. Conclusions: It is important to establish the molecular diagnosis early to avoid repeated and long-term screening for Wilms tumor. Our work further emphasizes that a wide range of ocular phenotypes are associated with loss of function PAX6 mutations. In addition to the possibility of stochastic variations, other genetic variations could play a role as modifier genes, thus giving rise to the observed different ocular phenotypes.

Overexpression of brain and acute leukemia cytoplasmic (BAALC) gene confers poor prognosis in cytogenetically normal acute myeloid leukemia (AML) patients, while less defined is its role in AML with abnormal karyotype. We evaluated the effect of BAALC overexpression on outcome of 175 adult AML patients with different cytogenetic risks. Karyotype was favorable in 13, intermediate in 117 and unfavorable in 45 patients, respectively. Quantitative BAALC expression was determined by real‐time PCR, with cut off value set at 50th percentile. BAALC was overexpressed in 87/175 (50%) patients, without association with cytogenetic status. High BAALC was associated with unmutated NPM (P = 0.006) and CD34 positivity (P < 0.0001). Complete remission (CR) was attained in 111 patients (63%), and was maintained at 5 years in 52 ± 7%. BAALC overexpression had a negative impact on CR achievement (P = 0.04), while did not influence relapse probability. Median survival was 22 months with a 5‐years overall survival (OS) of 35%. Factors with a negative impact on OS were older age (P = 0.0001), unfavorable cytogenetic (P = 0.005), ABCG2 overexpression (P = 0.03) and high BAALC levels (P = 0.01). We observed a worse outcome in patients with high BAALC expression through all cytogenetic risk categories: 5‐years OS was 100% vs. 71% in patients with favorable cytogenetics (P = 0.05), 55% vs. 40% in cases with intermediate karyotype (P = 0.04) and 34% vs. 23% in unfavorable cytogenetic subgroup (P = 0.02). BAALC overexpression identified AML patients with poor prognosis in all cytogenetic groups. Though relatively rare, BAALC positivity in patients with favorable or unfavorable karyotype significantly worsened survival. Am. J. Hematol. 88:848–852, 2013.

The HEX gene encodes for a homeodomain-containing transcription factor that controls various phases of vertebrate development. During development, as well as in adult, HEX is expressed in several different tissues including thyroid, liver, lung, mammary gland, haematopoietic progenitors, and endothelial cells, suggesting that this gene is subjected to a complex transcriptional regulation. In this study, we have evaluated the presence of different enhancers in the HEX gene region by using a phylogenetic approach. Several non-coding sequences, conserved between human and mouse, were selected. Four conserved sequences showed enhancer activity in MCF-7 cells. Two of these enhancers (located in the first and third intron, respectively) have been previously identified by other experimental approaches. These elements, as well as one among the new identified enhancers (located 2 kb 3′ to the HEX gene), are able to activate the HEX minimal promoter “in trans.” The activity of the 3′ enhancer was strongly reduced by overexpression of HDAC3.

Background: Prohibitin (PHB) is a multifunctional protein that is localized in different intracellular sites. PHB may exert different roles in tumorigenesis, having either a permissive action on tumor growth or an oncosuppressor role, depending on the cellular context. The objective of this study was to evaluate PHB expression in normal thyroid tissues, thyroid follicular adenomas (FAs), and papillary thyroid carcinomas (PTCs). Methods: PHB expression was analyzed by immunohistochemistry, Western blot, and quantitative reverse transcription polymerase chain reaction (RT-PCR). Transfections in the BCPAP and TPC-1 thyroid cancer cell lines were used to evaluate the PHB promoter activity. Results: In terms of protein and mRNA levels, normal tissues from patients with serum thyrotropin (TSH) values >0.8 mU/L had PHB levels that were significantly reduced compared to specimens from patients with serum TSH values V600E mutation. Notably, cell transfection experiments suggested that presence of the BRAF^V600E mutation may be associated to increase of the PHB promoter activity. Conclusions: PHB is overexpressed in PTCs bearing the BRAF^V600E mutation. We postulate that the presence of the BRAF^V600E mutation increases PHB promoter activity and therefore potentially mediates effects of this mutation on the behavior of BRAF^V600E positive PTCs.

The embryonic rat ventricle H9c2 cells maintain a proliferative state (P condition) in the presence of 10% FCS. However, by reducing serum concentration and in the presence of retinol acetate, proliferation is stopped, myogenic transdifferentiation is inhibited while cardiac differentiation is preserved (D condition). Two-dimensional gel electrophoresis and mass spectrometry analysis was used to define the modifications of the nuclear proteome occurring during the P-to-D transition. Among the proteins observed as modified, a reduced expression of the SM22/transgelin protein was associated with the D state. Also SM22 mRNA levels were reduced during P-to-D transition. Cell transfection experiments indicated that this decrease was partially due to a reduction of the SM22 promoter activity. GATA-4 had a repressive effect on SM22 promoter activity. Thus, since GATA-4 is known as a target of retinoids and may act as a transcriptional repressor, a mechanism to explain the SM22 reduction during the P-to-D transition is tentatively proposed. Immunohistochemical studies on heart cells confirmed the nuclear localization of SM22. Moreover, a differential expression of this protein in different districts of the human heart embryo was detected. Therefore, these data suggest that SM22 expression is regulated during heart development.

PAX6 mutations cause aniridia as well as other various congenital eye abnormalities. Aniridia can be due to both point mutations and chromosomal deletions/rearrangements. Therefore, a complete search for PAX6 gene alterations in aniridia subjects requires a technically complex approach involving the comprehension of fluorescence in situ hybridization (FISH) analysis. In the present study, an Italian casistic of aniridia patients has been investigated and a quantitative polymerase chain reaction (PCR) assay to detect PAX6 gene deletions was set up. Twenty-one aniridia patients were screened for point mutations (missense, nonsense, splicing-affecting, and short insertion/deletion) by using single-stranded conformational polymorphism (SSCP) and denaturing high performance liquid chromatography (dHPLC). To reveal deletions not detectable by SSCP or dHPLC, a quantitative PCR approach was set up for the PAX6 structural gene and for regions 5' and 3' to it at the level of WT1 and ELP4, respectively. Point mutations were found in 7 out of 21 patients. Three out of twenty-one patients showed deletions at the level of the PAX6 structural gene. In addition, two familial cases showed an undamaged PAX6 gene but a deletion in the region 3' to it at level of the ELP4 gene. In one of the families, the presence of the deletion has been confirmed by linkage analysis of polymorphic markers. In our casistic, a significant fraction of familial aniridia patients appears to be caused by a 3' deletion to PAX6, suggesting that evaluation of this alteration should be included in routine procedures of aniridia patients analysis. The quantitative PCR assay described here represents a simple approach to accomplish this task.

Objective. Preeclampsia is considered as a multifactorial disorder with a genetic predisposition. Alterations in the endothelin-1 (ET-1) system are considered to take part in triggering the vasoconstriction seen in preeclampsia. Methods. In order to investigate the possible association of the −231 G > A polymorphism in the endothelin-1 type A receptor gene (EDNRA), previously shown to be associated with other conditions characterized by vasospasm, we examined 77 Caucasian preeclamptic women and 67 matched controls including normotensive subjects without history of thromboembolic event, abnormalities in blood pressure, proteinuria, edema and preeclampsia. The genotype was assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) on genomic DNA extracted from blood samples. Case vs. control allele frequencies and genotype distributions were compared. Results. No significant differences were found when considering both genotype (χ² = 0.58, p = 0.75) and allelic frequencies (χ² = 0.08, p = 0.77). Furthermore, no significant genotype-related difference was found in relation to clinical features, such as gestational age at onset, systolic and diastolic blood pressure, proteinuria on admission and delivery week. Conclusions. No association between the −231 G > A polymorphism in the EDNRA gene and preeclampsia as well as any correlation with the main clinical features of the disorder were found, thus excluding a role for this polymorphism in susceptibility to preeclampsia.

Pax6 controls eye, pancreas and brain morphogenesis. In humans, heterozygous PAX6 mutations cause aniridia and various other congenital eye abnormalities. Most frequent PAX6 missense mutations are located in the paired domain (PD), while very few missense mutations have been identified in the homeodomain (HD). In the present report, we describe a molecular analysis of the human PAX6 R242T missense mutation, which is located in the second helix of the HD. It was identified in a male child with partial aniridia in the left eye, presenting as a pseudo-coloboma. Gel-retardation assays revealed that the mutant HD binds DNA as well as the wild-type HD. In addition, the mutation does not modify the DNA-binding properties of the PD. Cell transfection assays indicated that the steady-state levels of the full length mutant protein are higher than those of the wild-type one. In cotransfection assays a PAX6 responsive promoter is activated to a higher extent by the mutant protein than by the wild-type protein. In vitro limited proteolysis assays indicated that the presence of the mutation reduces the sensitivity to trypsin digestion. Thus, we suggest that the R242T human phenotype could be due to abnormal increase of PAX6 protein, in keeping with the reported sensitivity of the eye phenotype to increased PAX6 dosage.

To examine whether severe rheumatoid arthritis (RA) carries a -238 or +489 tumor necrosis factor-alpha (TNF-alpha) genotype different from mild-moderate RA. We investigated 163 patients (66 with severe disease) and 67 healthy blood donor controls. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism. Patients with severe RA (all active disease despite disease modifying antirheumatic drug combination therapy) disclosed the -238 GG genotype in 100% of cases versus 92.8% of the mild-moderates and 92.5% of controls (OR 11.7, Cl 0.6-216, p = 0.03). The +489 AA genotype was seen less often in patients than in controls (OR 4.2. CI 0.97-18.4, p = 0.045), and the contribution to this trend appeared predominant in the anti-TNF treated subgroup. The -238 AG genotype was absent in severe RA; in contrast, patients with mild-moderate RA disclosed the same frequency as controls. Thus -238 GG homozygosity is associated with severe RA. The +489 AA genotype might instead protect against worse outcome in RA.