Paolo Colomba

Effects of carboxyamidotriazole on in vitro models of imatinib-resistant chronic myeloid leukemia.

Although imatinib mesylate (IM) has revolutionized the treatment of chronic myeloid leukemia (CML), some patients develop resistance with progression of leukemia. Alternative or additional targeting of signaling pathways deregulated in bcr‐abl‐driven CML cells may provide a feasible option for improving clinical response and overcoming resistance. In this study, we show that carboxyamidotriazole (CAI), an orally bioavailable calcium influx and signal transduction inhibitor, is equally effective in inhibiting the proliferation and bcr‐abl dependent‐ and independent‐signaling pathways in imatinib‐resistant CML cells. CAI inhibits phosphorylation of cellular proteins including STAT5 and CrkL at concentrations that induce apoptosis in IM‐resistant CML cells. The combination of imatinib and CAI also down‐regulated bcr‐abl protein levels. Since CAI is already available for clinical use, these results suggest that it may be an effective addition to the armamentarium of drugs for the treatment of CML. J. Cell. Physiol. 215: 111–121, 2008.

Misdiagnosis of familial Mediterranean fever in patients with Anderson-Fabry disease.

Fabry disease (FD) is an underdiagnosed pathology due to its symptomatology that overlaps with various systemic and rheumatic disorders, including familial Mediterranean fever (FMF). We examined the Mediterranean fever (MEFV) and α‐galactosidase A (GLA) genes, whose mutations are responsible for FMF and FD, respectively, in 42 unrelated patients diagnosed with FMF, which revealed significant ambiguity regarding some of the symptoms which are also present in FD. The objective of this study was to determine the spectrum of mutations present in these genes, in order to identify cases of mistaken diagnosis of FMF and/or missed diagnosis of FD. Ten out of 42 patients had one mutation in homozygosis or two different mutations in heterozygosis in the MEFV gene; 20/42 had a single heterozygous mutation, and 12/42 did not have genetic alterations in MEFV. The analysis of the GLA gene conducted on all the samples revealed that three subjects, and some members of their families, had two different exonic mutations associated with FD. Family studies allowed us to identify eight other cases of FD, bringing the total undiagnosed subjects to 11/53. Analyzing the MEFV and GLA genes in patients with clinical diagnoses of FMF proved to be fundamentally important for the reduction of diagnostic errors.

Role of S128R polymorphism of E-selectin in colon metastasis formation

The extravasation of cancer cells is a key step of the metastatic cascade. Polymorphisms in genes encoding adhesion molecules can facilitate metastasis by increasing the strength of interaction between tumor and endothelial cells as well as impacting other properties of cancer cells. We investigated the Ser128Arg (a561c at the nucleotide level) polymorphism in the E‐selectin gene in patients with metastatic colon cancer and its functional significance. Genotyping for a561c polymorphism was performed on 172 cancer patients and on an age‐matched control population. The colon cancer group was divided into groups with (M+) and without observable metastasis (M−). For in vitro functional assays, Huvec transfected cells expressing wild‐type (WT) or the S128R variant of E‐selectin were established to study in vitro binding ability and signal transduction processes of T84 colon cancer cell line. Our results demonstrated that the Arginine128 allele was more prevalent in the M+ group than in the M− group or normal controls (p < 0.005; odds ratio, 1.56; 95% confidence interval (CI) 1.16–1.92; p < 0.001, odds ratio = 1.65; CI = 1.24–1.99, respectively). In vitro, S128R E‐selectin transfected Huvec cells, supported increased adhesion as well as increased cellular signaling of T84 cancer cells compared to WT E‐selectin and mock‐transfected Huvec cells. These findings suggest that the E‐selectin S128R polymorphism can functionally affect tumor‐endothelial interactions as well as motility and signaling properties of neoplastic cells that may modulate the metastatic phenotype.

Antiproteinuric effect of add-on paricalcitol in Fabry disease patients: a prospective observational study

BACKGROUND Proteinuria is the predominant risk factor for renal disease progression in Fabry disease (FD). When urine protein excretion is controlled to <0.50 g/24 h, the rate loss of glomerular filtration rate (GFR) is not significantly different from 0. However, enzyme replacement therapy (ERT) alone does not decrease proteinuria and it has been recommended that patients receiving ERT also receive anti-renin-angiotensin system (RAS) therapy. Emerging evidence show that paricalcitol (PCT) reduces proteinuria in the presence of intensified inhibition of RAS; however, there is no evidence in FD. We evaluated the antiproteinuric effect of PCT in FD patients with proteinuria >0.50 g/24 h persisting despite ERT and anti-RAS therapy titrated to maximum tolerated dosage. METHODS Fifteen FD patients were selected and studied in the first 6 months of add-on oral PCT (1 µg/day) and, in order to verify the dependence of proteinuria reduction on PCT, 3 months after drug withdrawal. RESULTS At baseline, proteinuria was 1.3 ± 0.6 g/24 h. Six months of add-on PCT significantly decreased proteinuria to 0.4 ± 0.3 g/24 h, with levels <0.50 g/24 h achieved in four patients at Month 1, six at Month 3, and in 12 by Month 6, in the absence of changes to BP and GFR. Proteinuria recovered to basal value after drug withdrawal. CONCLUSIONS In conclusion, our study is the first evidence that PCT is effective in reducing proteinuria in FD patients in the presence of ERT and anti-RAS therapy.

A classical phenotype of Anderson-Fabry disease in a female patient with intronic mutations of the GLA gene: a case report

BackgroundFabry disease (FD) is a hereditary metabolic disorder caused by the partial or total inactivation of a lysosomal hydrolase, the enzyme α-galactosidase A (GLA). This inactivation is responsible for the storage of undegraded glycosphingolipids in the lysosomes with subsequent cellular and microvascular dysfunction. The incidence of disease is estimated at 1:40,000 in the general population, although neonatal screening initiatives have found an unexpectedly high prevalence of genetic alterations, up to 1:3,100, in newborns in Italy, and have identified a surprisingly high frequency of newborn males with genetic alterations (about 1:1,500) in Taiwan.Case presentationWe describe the case of a 40-year-old female patient who presented with transient ischemic attack (TIA), discomfort in her hands, intolerance to cold and heat, severe angina and palpitations, chronic kidney disease. Clinical, biochemical and molecular studies were performed.ConclusionsReported symptoms, peculiar findings in a renal biopsy – the evidence of occasional lamellar inclusions in podocytes and mesangial cells – and left ventricular (LV) hypertrophy, which are considered to be specific features of FD, as well as molecular evaluations, suggested the diagnosis of a classical form of FD.We detected four mutations in the GLA gene of the patient: -10C>T (g.1170C>T), c.370-77_-81del (g.7188-7192del5), c.640-16A>G (g.10115A>G), c.1000-22C>T (g.10956C>T). These mutations, located in promoter and intronic regulatory regions, have been observed in several patients with manifestations of FD. In our patient clinical picture showed a multisystemic involvement with early onset of symptoms, thus suggesting that these intronic mutations can be found even in patients with classical form of FD.

High Variability of Fabry Disease Manifestations in an Extended Italian Family

Fabry disease (FD) is an inherited metabolic disorder caused by partial or full inactivation of the lysosomal hydrolase α-galactosidase A (α-GAL). The impairment of α-GAL results in the accumulation of undegraded glycosphingolipids in lysosomes and subsequent cell and microvascular dysfunctions. This study reports the clinical, biochemical, and molecular characterization of 15 members of the same family. Eight members showed the exonic mutation M51I in the GLA gene, a disease-causing mutation associated with the atypical phenotype. The clinical history of this family highlights a wide phenotypic variability, in terms of involved organs and severity. The phenotypic variability of two male patients is not related to differences in α-GAL enzymatic activity: though both have no enzymatic activity, the youngest shows severe symptoms, while the eldest is asymptomatic. It is noticeable that for two female patients with the M51I mutation the initial clinical diagnosis was different from FD. One of them was diagnosed with Familial Mediterranean Fever, the other with Multiple Sclerosis. Overall, this study confirms that the extreme variability of the clinical manifestations of FD is not entirely attributable to different mutations in the GLA gene and emphasizes the need to consider other factors or mechanisms involved in the pathogenesis of Fabry Disease.

Molecular and clinical studies in five index cases with novel mutations in the GLA gene

Fabry disease is a metabolic and lysosomal storage disorder caused by the functional defect of the α-galactosidase A enzyme; this defect is due to mutations in the GLA gene, that is composed of seven exons and is located on the long arm of the X-chromosome (Xq21-22). The enzymatic deficit is responsible for the accumulation of glycosphingolipids in lysosomes of different cellular types, mainly in those ones of vascular endothelium. It consequently causes a cellular and microvascular dysfunction. In this paper, we described five novel mutations in the GLA gene, related to absent enzymatic activity and typical manifestations of Fabry disease. We identified three mutations (c.846_847delTC, p.E341X and p.C382X) that lead to the introduction of a stop codon in positions 297, 341 and 382. Moreover we found a missense mutation (p.R227P) in the exon 5 of the GLA gene and a single point mutation (c.639+5 G>T) occurring five base pairs beyond the end of the exon 4. These mutations have never been found in our group of healthy control subjects >2300. The studied patients presented some clinical manifestations, such as cornea verticillata, hypo-anhidrosis, left ventricular hypertrophy, cerebrovascular disorders and renal failure, that, considering the null enzymatic activity, suggest that the new mutations reported here are related to the classic form of Fabry disease. The identification of novel mutations in patients with symptomatology referable to FD increases the molecular knowledge of the GLA gene and it gives clinicians an important support for the proper diagnosis of the disease.

Effects of Parietaria judaica pollen extract on human microvascular endothelial cells

Pollinosis from Parietaria judaica is one of the main causes of allergy in the Mediterranean area. The present study is designed to assess if P. judaica pollens contain bioactive compounds able to elicit a functional response in endothelial cells. We have demonstrated that addition of pollen extract to human lung microvascular endothelial cells (HMVEC-L) induces a modification of cell morphology, actin cytoskeletal rearrangements and an increase in endothelial cell permeability. We further showed that the treatment of endothelial cells with pollen extract causes an increase of E-selectin and VCAM-1 protein levels as well as an increase of IL-8 production. The stimulation of cell-cell adhesion molecules was paralleled by a dose-dependent increase of adhesion of polymorphonuclear cells (PMNs) to HMVEC-L monolayer. Our results suggest for the first time that pollen affect directly endothelial cells (EC) modulating critical functions related to the inflammatory response.

A family with various symptomatology suggestive of Anderson-Fabry disease and a genetic polymorphism of alpha galactosidase A gene.

BACKGROUND Anderson/Fabry disease expresses a wide range of clinical variability in patients that it is possible to explain referring to a genetic variability with numerous mutations described in the literature (more than 600). METHODS We report some clinical cases of some members of a Sicilian family to express phenotypical variability of this disease in subjects with the same genetic mutation RESULTS The first case was a 59-year-old female. Brain MRI revealed right frontal periventricular white matter of likely vascular-degenerative origin. The probands alpha galactosidase A activity was 3.7nmol/mL/h. Molecular genetics revealed a polymorphism: -10 C>T; IVS 2-76_80del5; IVS4-16 A>G; IVS6-22 C>T. The second case was a 30year-old male affected by acroparesthesias and hypoidrosis since he was an adolescent. Renal impairment was first detected at age 29; it began with high plasma levels of creatinine and microalbuminuria date. The third case was a 41year-old daughter that presented with acroparesthesias, hypoidrosis since she was very young. The patients alpha galactosidase A activity was 4.1nmol/mL/h, in whole blood, which is compatible with heterozygote subject for Fabrys disease or healthy control. The fourth case was a male grandson of the proband, 9year-old child. He had a classic gastrointestinal involvement. He complained of recurrent abdominal pain, post prandial bloating and pain. This childs enzyme activity was 1.65nmol/mL/h. In cases 2, 3, and 4, molecular genetics revealed a polymorphism: -10 C>T; IVS 2-76_80del5; IVS4-16 A>G; IVS6-22 CG, IVS6-22C>T polymorphisms occurred in 8.9% and 3.7% of the subjects respectively, and the significance of this haplotype in FD pathology remains unknown but possibly suggestive of Anderson/Fabry disease.

Novel α-galactosidase a mutation in patients with severe cardiac manifestations of fabry disease

Fabry disease (FD) is a hereditary metabolic disorder caused by the partial or total inactivation of α-galactosidase A (α-gal A), a lysosomal hydrolase. This inactivation is responsible for the accumulation of undegraded glycosphingolipids in the lysosomes with subsequent cellular and microvascular dysfunction. Fabry is considered a rare disease, with an incidence of 1:40,000; however, there are good reasons to believe that it is often seen but rarely diagnosed. To date, more than 600 mutations have been identified in human GLA gene that are responsible for FD. We describe the case of a 54-year-old male patient, who presented with left ventricular hypertrophy, chronic renal failure and acroparaesthesias, which are considered to be specific features of FD. Clinical and instrumental investigations showed several cardiovascular manifestations. The molecular analysis of GLA gene revealed a novel mutation in the fifth exon, called N249K, and the enzymatic analysis showed no α-galactosidase A activity. Family screening detected the same mutation in some relatives and also the enzymatic analysis confirmed the diagnosis of FD. In conclusion, these data suggest that the N249K mutation may be associated with cardiac manifestations of FD combined with other classical features of the disease.