Molecular pathology and genetics of pancreatic endocrine tumours

Pancreatic neuroendocrine tumours (PETs) are the second most frequent pancreatic neoplasms. Their poor chemosensitivity, high rate of metastatic disease and relatively long survival make PETs an ideal field to be explored for novel therapies based on specific molecular changes. PETs are generally sporadic but can also arise within hereditary syndromes, such as multiple endocrine neoplasia type 1, von Hippel-Lindau, neurofibromatosis type 1 and tuberous sclerosis complex, which represent a model for sporadic cases too. Among allelic imbalances, main genomic changes involve gain of 17q, 7q and 20q and loss of 11q, 6q and 11p, which identify regions of putative candidate oncogenes or tumour suppressor genes (TSGs), respectively, sometime with potential prognostic significance. Overexpression of Src-like kinases and cyclin D1 (CCND1) oncogene has been described. As for TSGs, P53 (TP53), DPC4/SMAD4 and RB (RB1) are not implicated in PET tumorigenesis, while for p16INK4a (CDKN2A), TIMP3, RASSF1A and hMLH1, more data are available, suggesting a role for methylation as a silencing mechanism. In the last decade, gene expression profile studies, analysis of microRNAs and, more recently, large-scale mutational analysis have highlighted commonly altered molecular pathways in the pathology of PETs. The roles of the mammalian target of rapamycin pathway, and its connection with Src kinases, and the activity of a number of tyrosine kinase receptors seem to be pivotal, as confirmed by the results of recent clinical trials with targeted agents. Mutations of DAXX and ATRX are common and related to altered telomeres but not to prognosis.     

Comprehensive investigation of genetic variation in the 8q24 region and multiple myeloma risk in the IMMEnSE consortium

Genome-wide association studies (GWAS) have shown that the 8q24 region harbours multiple independent cancer susceptibility loci, even though it is devoid of genes. Given that no GWAS data are currently available for multiple myeloma (MM), we tested the hypothesis that genetic variants in this region could play a role in MM risk. We genotyped 20 single nucleotide polymorphisms of 8q24 in 1188 MM cases and 2465 controls and found a statistically significant (P = 0·0022) association between rs2456449 and MM risk. These data provide further evidence that the genetic variability in the 8q24 region is associated with cancer risk, particularly haematological malignancies.     

The thrombophilic pattern of different clinical manifestations of venous thromboembolism: a survey of 443 cases of venous thromboembolism

Although pulmonary embolism (PE) and deep vein thrombosis (DVT) share many risk factors, it is uncertain whether thrombophilic abnormalities may impact differently on the development of these two clinical manifestations of venous thromboembolism (VTE). To give further insight into this issue, we estimated the association of PE with different types of thrombophilia and evaluated whether these abnormalities have a different prevalence in patients presenting with PE, alone or associated with DVT, as compared with those with isolated DVT. In this study 443 consecutive patients with a first episode of VTE and 304 matched healthy controls underwent laboratory screening for thrombophilia, including natural anticoagulants, factor V Leiden and prothrombin G20210A polymorphisms, antiphospholipid antibodies, homocysteine, factor VIII, and lipoprotein(a). Of the 443 patients, 224 patients had isolated DVT, 144 had combined DVT/PE, and 75 had isolated PE. At least one thrombophilic abnormality was detected in 72.8% of DVT, 66% of DVT/EP, and 60% of isolated PE patients. A high prevalence of hyperhomocysteinemia and elevated lipoprotein(a) levels was found in all patients with no significant differences among the three groups. The prevalence of prothrombin G20210A polymorphism and of elevated factor VIII levels was significantly higher in patients with DVT and DVT/PE than in controls, but not in those with isolated PE, whereas factor V Leiden polymorphism was associated with isolated DVT but not with DVT/PE or isolated PE. In conclusion, the thrombophilic burden seems different in isolated PE versus DVT with or without PE, suggesting that PE may encompass a different pathophysiological process of thrombosis to DVT.     

Exercise training improves vascular endothelial function in patients with type 1 diabetes

OBJECTIVE-Impaired endothelial function of resistance and conduit arteries can be detected in patients with type 1 diabetes. We studied whether a persistent improvement of endothelial function can be achieved by regular physical training. RESEARCH DESIGN AND METHODS-The study included 26 patients with type 1 diabetes of 20 +/- 10 years' duration and no overt angiopathy; 18 patients (42 +/- 10 years old) participated in a bicycle exercise training program, and 8 patients with type 1 diabetes (33 +/- 11 years old) served as control subjects. Vascular function of conduit arteries was assessed by flow-mediated and endothelium-independent dilation of the brachial artery and of resistance vessels by the response of ocular fundus pulsation amplitudes to intravenous N(G)-monomethyl-L-arginine (L-NMMA) at baseline, after 2 and 4 months of training, and 8 months after cessation of regular exercise. RESULTS-Training increased peak oxygen uptake (VO(2max)) by 13% after 2 months and by 27% after 4 months (P = 0.04). Flow-mediated dilation (FMD) of the brachial artery increased from 6.5 +/- 1.1 to 9.8 +/- 1.1% (P = 0.04) by training. L-NMMA administration decreased fundus pulsation amplitude (FPA) by 9.1 +/- 0.9% before training and by 13.4 +/- 1.5% after 4 months of training (P = 0.02). VO(2max), FMD, and FPA were unchanged in the control group. Vascular effects from training were abrogated 8 months after cessation of exercise. CONCLUSIONS-Our study demonstrates that aerobic exercise training can improve endothelial function in different vascular beds in patients with long-standing type 1 diabetes, who are at considerable risk for diabetic angiopathy. However, the beneficial effect on vascular function is not maintained in the absence of exercise.     

Meal-related structured self-monitoring of blood glucose: effect on diabetes control in non-insulin-treated type 2 diabetic patients

OBJECTIVE: To investigate the effect of meal-related self-monitoring of blood glucose on glycemic control and well-being in non-insulin-treated type 2 diabetic patients. RESEARCH DESIGN AND METHODS: This 6-month study, which included 6 months of follow-up, adopted a prospective, multicenter, randomized controlled design. Subjects were randomized to two groups: one group used a blood glucose-monitoring device, kept a blood glucose/eating diary, and received standardized counseling; the control group received nonstandardized counseling on diet and lifestyle. The primary efficacy parameter was the change in HbA(1c). Secondary efficacy variables included changes in body weight, lipids, and microalbumin and changes in treatment satisfaction and well-being. RESULTS: In the per-protocol analysis, the use of a self-monitoring blood glucose device significantly reduced HbA(1c) levels by 1.0 +/- 1.08% compared with 0.54 +/- 1.41% for the control group (P = 0.0086); subgroup analysis showed three types of responders. Body weight, total cholesterol, and microalbumin improved when using a glucometer, but there was no statistically significant difference between the two groups. Treatment satisfaction increased in both groups to a similar extent (P = 0.9). Self-monitoring resulted in a marked improvement of general well-being with significant improvements in the subitems depression (P = 0.032) and lack of well-being (P = 0.02). CONCLUSIONS: Meal-related self-monitoring of blood glucose within a structured counseling program improved glycemic control in the majority of non-insulin-treated type 2 diabetic patients in this study. The finding of three types of responders will be important for future planning of counseling and educational interventions.     

Management of 46, XY partial gonadal dysgenesis--revisited

46, XY partial gonadal dysgenesis is a rare condition characterized by a varying degree of testicular dysgenesis, ambiguous genitalia, and usually absence of regression of Müllerian structures. The management of patients with these disorders warrants revisiting, owing to recent molecular biological findings and to reports on the long-term outcome of individuals with ambiguous genitalia. We report on a patient with 46, XY chromosomes, presence of the "sex-determining region of Y chromosome" (SRY) gene, scrotal gonads, fallopain tubes, uterus, vagina, and ambiguous genitalia with a penisoid, perineal hypospadia and sinus urogenitalis. Gonadal biopsy revealed virtually normal testicular tissue in both gonads. Removal of the gonads during surgery for a cystic adnex tumor revealed clear signs of partial gonadal dysgenesis. The decision to raise the child as a male was made by parents and physicians caring for the patient. Administration of testosterone, removal of the uterus and adnexes, in addition to repair of the hypospadia permitted an almost normal penis to be formed with normal male micturition. In the management of affected patients it has to be considered that establishing the diagnosis may be extremely tricky, even with the use of gonadal biopsies. The decision on sex assignment may be even more difficult, since future gender identity, limitations of genital reconstructive surgery and the potential for development of gonadal tumors have to be taken into consideration. While in the past, female sex assignment was commonly recommended for such patients, raising them in a male gender role is now considered. Parents should be involved in the decision that is ultimately based on extensive analysis of the individual case.     

Nonviral and viral gene transfer into different subsets of human dendritic cells yield comparable efficiency of transfection

Among the many promising cancer immunotherapeutic strategies, dendritic cells (DC) have become of particular interest. This study aims to optimize a clinical grade protocol for culture and transfection of human DC. Monocytes and CD34(+) hematopoietic stem cells (HSC) from same donor were differentiated under serum-free conditions and analyzed for their susceptibility to several recently described nonviral transfection methods as compared with established virally mediated gene transfer. Nonviral gene transfer methods studied were square-wave electroporation, lipofection, and particle-mediated transfer of plasmid DNA or in vitro transcribed mRNA. We conclude that DNA is not suitable for transduction of DC using nonviral methods. In contrast, mRNA and square-wave electroporation reproducibly yields 60% and 50% transfected monocyte- and CD34(+)-derived DC, respectively, measured at protein level, without affecting the cell viability. Thus, the transfection efficiency of this method is comparable with the 40-90% transgene expression obtained using retroviral (RV) or adenoviral (AdV) vectors in CD34(+)- and monocyte-derived DC, respectively. In monocyte-derived DC, however, the amount of protein expressed per-cell basis was higher after AdV (MOI = 1000) compared with mRNA electroporation-mediated transfer. This is the first study directly demonstrating side-by-side that mRNA electroporation into DC of different origin indeed results in a comparable number of transduced cells as when using virus-mediated gene transfer.     

Lipoprotein(a) and homocysteine as genetic risk factors for vascular and neuropathic diabetic foot in type 2 diabetes mellitus

Neuropathy and peripheral artery disease represent the main pathophysiological conditions underlying diabetic foot. Several studies showed that Lipoprotein(a)-Lp(a)-and homocysteine (Hcy) can be associated with diabetic complications, but their relationship with diabetic foot is unclear. Aim of this study was to investigate whether Lp(a) and Hcy were associated with diabetic foot ulcerations, classified according to the presence of peripheral artery disease (PAD) or neuropathy. From among consecutive type 2 diabetic attending at the Diabetic Foot Clinic 27 subjects with vascular diabetic foot (VDF), 43 with neuropathic diabetic foot (NDF) and 52 controls without foot ulceration, neuropathy, and PAD were enrolled. Both Lp(a) (26.1 ± 22.7 vs. 14.9 ± 19.5 mg/dl; P = 0.003) and Hcy levels (15.4 ± 5.7 vs. 12.2 ± 5.1 μmol/l; P = 0.022) were significantly greater in the VDF group than in controls. Lp(a) levels were significantly lower in the NDF group than in controls (6.9 ± 8.1 versus 14.9 ± 19.5 mg/dl; P = 0.009), while no difference in Hcy levels was found. Multiple logistic regression analysis showed that Hcy was associated with VDF (OR: 1.11; 95% CI: 1.07-14.1; P = 0.048). Lp(a) did not enter the model, but its P-value was very near to the significant level (OR: 1.09; 95% CI: 0.99-12.05; P = 0.059). Moreover, low Lp(a) levels were associated with NDF (OR: 0.84; 95% CI: 0.21-0.96; P = 0.039). Our study has shown for the first time that high Lp(a) and Hcy levels are associated with the development of VDF, while low Lp(a) levels appear to be associated with delayed wound healing in patients with neuropathic foot ulcerations.     

Course of serum 25-hydroxyvitamin D<Subscript>3</Subscript> status and its influencing factors in adults undergoing allogeneic hematopoietic cell transplantation

Hypovitaminosis D (<30 ng/ml) is highly prevalent in allogeneic hematopoietic cell transplantation (alloHCT), but the relevance of influencing factors for serum 25-hydroxyvitamin D₃ [25(OH)D₃] status in adult patients remains unknown. We are the first to have prospectively assessed 25(OH)D₃ status and its influencing factors in 102 patients before and at days +30 and +100 after alloHCT. Among others, we evaluated age, gender, weight, fat mass, season, sun exposure habits, and dietary and supplemental vitamin D intake as factors potentially influencing baseline vitamin D status in uni- and multivariate linear regression analysis. Furthermore, we investigated the impact of changes in fat mass, duration of parenteral nutrition, and acute graft-versus-host disease (aGVHD) on the course of serum 25(OH)D₃. Baseline 25(OH)D₃ concentrations were 16.4 ± 8.9 ng/ml, revealing that the majority (89%) had concentrations beneath the normal range. In multivariate linear regression model, only higher body fat mass remained an independent risk factor for reduced baseline 25(OH)D₃ concentrations (P = 0.007). In the early post-transplant period, 25(OH)D₃ status remained low, revealing a tendency to further deterioration, especially in patients with corticosteroid-treated aGVHD (≥II). Reduced vitamin D status was very common in these patients before and after alloHCT, whereby the most important influencing factors, namely season and dietary factors seem to have little impact. Our findings suggest that monitoring and if necessary, correcting vitamin D status may be indicated at regular intervals before alloHCT and during long-term follow-up. Further investigations of these patients' vitamin D requirements are needed, especially if they are on long-term corticosteroids.     

Systemic-onset juvenile idiopathic arthritis complicated by early onset amyloidosis in a patient carrying a mutation in the <Emphasis Type="Italic">MEFV</Emphasis> gene

Systemic juvenile idiopathic arthritis (SJIA) is a disorder characterized by arthritis in children starting before 16 years of age associated with daily high fever, persisting for more than 2 weeks, and at least one of the following clinical features: evanescent cutaneous rash, lymphadenopathy, serositis or hepatosplenomegaly. SJIA patients carry a significantly higher frequency of MEFV mutations, the gene responsible for familial Mediterranean fever, and may be characterized by a more aggressive disease. In this line, we describe a 9-year-old girl affected with SJIA who carried a heterozygous G196W mutation in MEFV. Our patient was characterized by an aggressive disease course, resistance to conventional immunosuppressive agents and developed renal amyloidosis just 2 years after the disease onset.