Terminal differentiation of human epidermal keratinocytes involves mitochondria- and caspase-dependent cell death pathway.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to P Marchetti.
Explore the source record for details and available documents.
BACKGROUND: Mutations in the p53 gene are the most common genetic alterations in human primary breast carcinoma and these mutations are often associated with worse prognosis and chemo/radioresistance. PATIENTS AND METHODS: The analysis of the p53 gene was performed by fluorescence-assisted mismatch analysis in 13 consecutive high-risk primary breast cancer (HR-BC) patients with 10 or more involved axillary nodes to evaluate its prognostic value. RESULTS: Three p53 mutations (23%) and four allelic variants were detected. After a median follow-up of 52 months the HR-BC disease-free survival (DFS) was 51% and overall survival 79%. All patients harboring a p53 mutation (p53(mut)) relapsed within 10 months of the median DFS while 67% of those showing a wild-type p53 status (p53(wt)) survive disease-free at a median follow-up of 43 months. One p53(mut) patient is still alive while all the p53(wt) patients survive at 56 months median follow-up. Two out of the four p53(wt) relapsing breast cancer patients showed the Arg72Pro allelic variant; one of these died at 75 months. CONCLUSIONS: p53 mutations may help identify a subset of very high risk breast cancer patients (vHR-BC) with worse prognosis.
Brain metastases from ovarian cancer are rare. A review of five autopsy studies reported brain metastases in 4% of 712 patients who died with a diagnosis of ovarian cancer. The prognosis is very poor and a consensus on the standard treatment is not available. We report the case of a patient who developed a solitary brain metastasis as single evidence of relapse, 26 months after the first diagnosis of ovarian cancer. A temporo-parietal craniotomy with excision of the mass and whole brain radiotherapy were performed. The patient is free of disease five months after radiotherapy completion. Also in patients suffering from neoplasms that rarely metastasize to CNS, a careful clinical examination may help to diagnose uncommon sites of disease relapse.
BACKGROUND: The relationships between lipid levels and atherosclerotic lesions of carotid arteries in kidney graft recipients are still unclear. METHODS: We evaluated carotid morphology in 53 recipients of functioning renal transplantation, and studied the relationship of carotid artery wall lesions with relevant clinical and laboratory risk factors for cardiovascular disease. The patients were on stable, cyclosporine-based immunosuppressive therapy. RESULTS: The main clinical characteristics of patients were: age, 46.5 +/- 10.1 years; males/females, 40/13; body mass index, 25.8 +/- 4.4 kg/m2; duration of transplantation, 43 +/- 52 months. Ultrasonographic scanning of carotid arteries showed the presence of lesions (intimal-media thickness and/or plaque) in 28 patients (52.8%). These recipients differed from patients without carotid lesions in terms of age (50.4 +/- 9.0 vs 42.2 +/- 9.7 years, p < 0.01) and duration of pre-transplant dialysis (4.6 +/- 3.4 vs 2.3 +/- 1.9 years, p < 0.01), whereas no statistically significant difference was observed as for total cholesterol (230 +/- 44 vs 235 +/- 35 mg/dl), LDL-cholesterol (142 +/- 32 vs 143 +/- 30 mg/dl), HDL-cholesterol (52 +/- 12 vs 58 +/- 20 mg/dl) and triglycerides (178 +/- 94 vs 167 +/- 89 mg/dl). The percentage of post-transplant diabetes was 3-fold higher in patients with carotid lesions (25 vs 8%). No difference was observed as for the following parameters: body mass index, duration of transplantation, fibrinogen levels, DDimer concentrations, reactive C-protein values, prevalence of hypertension, percentage of smokers vs non-smokers. CONCLUSIONS: The present study supports the view that carotid artery lesions in kidney graft recipients on stable, cyclosporine-based immunosuppressive therapy may not be related to circulating lipid values.
Actinic keratoses (AKs) are pre-neoplastic lesions that can develop into squamous cell carcinomas (SCCs) of the skin. Often AK and SCC have commonly altered p53. A status of another tumor suppressor, the p16(INK4a), was reported for SCC but not for AK. A comparative study of SCC and AK human samples by loss of heterozygosity (LOH) analysis determined that the p16(INK4a/ARF) locus is less frequently altered in AKs than in SCCs. These LOH data highly correlated with immunohistochemical findings demonstrating the presence of p16(INK4a) in the AK skin samples but its absence in SCC lesions. Our results imply that progression of AK into SCC may involve inactivation of p16(INK4a).
Explore the source record for details and available documents.
Hypersensitivity reactions caused by carboplatin rarely occur. These reactions can cause lethal complications and make subsequent therapeutic approaches difficult. To date, only a few cases of successful resolution of hypersensitivity by replacement of carboplatin with cisplatin have been reported. We report on a patient with serous papillary extra-ovarian peritoneal carcinoma who developed a hypersensitivity reaction after the 10th weekly administration of carboplatin. Two weeks after reaction, intradermal skin testing with paclitaxel, carboplatin, cisplatin, and mannitol showed intense reaction only to carboplatin. On the basis of these results, the patient was changed to a chemotherapy with cisplatin and paclitaxel. A further eight courses of chemotherapy were administered without evidence of hypersensitivity reactions. Carboplatin seems to be successfully replaceable by cisplatin in case of hypersensitivity reactions.
Immunoprotection of pancreatic islets for successful allo- or xenotransplantation without chronic immunosuppression is an attractive, but still elusive, approach for curing type 1 diabetes. It was recently shown that, even in the absence of fibrotic overgrowth, other factors, mainly insufficient nutrition to the core of the islets, represent a major barrier for long-term survival of intraperitoneal microencapsulated islet grafts. The use of dispersed cells might contribute to solve this problem due to the conceivably easier nutritional support to the cells. In the present study, purified bovine islets, prepared by collagenase digestion and density gradient purification, and dispersed bovine islet cells, obtained by trypsin and DNAsi (viability > 90%), were entrapped into either 2% (w/v) sodium alginate (commonly used for encapsulation purposes) or (dispersed islet cells only) macroporous gelatin microcarriers (CulthiSpher-S, commonly used for the production of biologicals by animal cells). Insulin release studies in response to glucose were performed within 1 week and after 1 month from preparation of the varying systems and showed no capability of dispersed bovine islet cells within sodium alginate microcapsules to sense glucose concentration changes. On the contrary, bovine islet cells entrapped in CulthiSpher-S microcarriers showed maintained capacity of increasing insulin secretion upon enhanced glucose concentration challenge. In this case, insulin release was approximately 60% of that from intact bovine islets within sodium alginate microcapsules. MTT and hematoxylineosin staining of islet cell-containing microcarriers showed the presence of viable and metabolically active cells throughout the study period. This encouraging functional data prompted us to test whether the microcarriers could be immunoisolated for potential use in transplantation. The microcarriers were embedded within 3% sodium alginate, which was then covered with a poly-L-lysine layer and a final outer alginate layer. Maintained insulin secretion function of this system was observed, which raises the possibility of using microencapsulated CulthiSpher-S microcarriers, containing dispersed pancreatic islet cells, in experimental transplantation studies.
An increasing number of experimental chemotherapeutic agents induce apoptosis by directly triggering mitochondrial membrane permeabilization (MMP). Here we examined MMP induced by lonidamine, arsenite, and the retinoid derivative CD437. Cells overexpressing the cytomegalovirus-encoded protein vMIA, a protein which interacts with the adenine nucleotide translocator, were strongly protected against the MMP-inducing and apoptogenic effects of lonidamine, arsenite, and CD437. In a cell-free system, lonidamine, arsenite, and CD437 induced the permeabilization of ANT proteoliposomes, yet had no effect on protein-free liposomes. The ANT-dependent membrane permeabilization was inhibited by the two ANT ligands ATP and ADP, as well as by recombinant Bcl-2 protein. Lonidamine, arsenite, and CD437, added to synthetic planar lipid bilayers containing ANT, elicited ANT channel activities with clearly distinct conductance levels of 20+/-7, 100+/-30, and 47+/-7 pS, respectively. Altering the ATP/ADP gradient built up on the inner mitochondrial membrane by inhibition of glycolysis and/or oxidative phosphorylation differentially modulated the cytocidal potential of lonidamine, arsenite, and CD437. Inhibition of F(0)F(1)ATPase without glycolysis inhibition sensitized to lonidamine-induced cell death. In contrast, only the combined inhibition of glycolysis plus F(0)F(1)ATPase sensitized to arsenite-induced cell death. No sensitization to cell death induction by CD437 was achieved by glucose depletion and/or oligomycin addition. These results indicate that ANT is a target of lonidamine, arsenite, and CD437 and unravel an unexpected heterogeneity in the mode of action of these three compounds.
Many anticancer drugs exert their cytotoxicity through DNA damage and induction of apoptosis. Small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC) have different sensitivity to treatment with radiation and chemotherapeutic agents with SCLC being more sensitive than NSCLC both in vitro and in vivo. This difference might be related to the different susceptibility of small and non-small cell lung carcinoma to undergo apoptosis. The aim of this study was to investigate if deficiencies in the apoptotic pathways can explain the intrinsic resistance of NSCLC to anti-cancer treatment. Three different triggers were used to induce apoptosis. Etoposide and gamma-radiation, which are important parts of clinical lung cancer treatment, induce DNA-damage, whereas Fas ligation induces receptor-mediated apoptotic pathways. NSCLC cells were cross-resistant to all treatments, whereas SCLC cells, which do not express pro-caspase-8, were resistant to alphaFas-, but not to DNA-damage-induced apoptosis. Cytochrome c release, activation of caspase-9 and the executioner caspase-3 were observed in both types of lung cancer cells. However, cleavage of known nuclear substrates for caspase-3, such as PARP and DFF45/ICAD, was documented only in the sensitive SCLC cells but not in the resistant NSCLC cells. Moreover, relocalization of active caspase-3 from the cytosol into the nucleus upon treatment was observed only in the SCLC cell line. These results indicate that the inhibition of apoptosis in NSCLC occurs downstream of mitochondrial changes and caspase activation, and upstream of nuclear events.
BACKGROUND: The potential benefits of islet xenografting in type 1 diabetes include the intriguing, but still unanswered, possibility that the grafted xenoislets may be less subjected to human autoimmune attack. Cytokines may play a major role in the pathogenesis of autoimmune diabetes by causing impairment of insulin release and pancreatic islet cell toxicity. METHODS: We compared insulin secretion, islet cell death and survival, inducible nitric oxide synthase (iNOS) mRNA expression, nitrite production, and Bcl-2 and Bax mRNA expression in isolated human and large mammal (bovine) islets exposed to 50 U/ml recombinant human interleukin-1, 1,000 U/ml recombinant human tumor necrosis factor-alpha and 1,000 U/ml recombinant human interferon-gamma. RESULTS: After 24-hr exposure, a marked decrease of glucose-stimulated insulin secretion was observed with human, but not with bovine islets. After 48-hr exposure, human, but not bovine, pancreatic islets showed a significantly higher percentage of apoptotic cells compared to controls. Treatment of human islets with human cytokines induced up-regulation of iNOS mRNA, increased levels of nitrites, and down-regulation of Bcl-2 mRNA, with unchanged levels of Bax mRNA. These parameters were not affected by cytokines in bovine islets. CONCLUSIONS: Bovine islets are less susceptible than human islets to the effects of human cytokines, which may be a potential advantage of xenotransplantation.
Several genes have been involved in the pathogenesis of hereditary breast/ovarian cancer (BOC), but mutations in the BRCA1 gene are by far the most recurrent. In this study, we report the identification of a founder mutation in a geographically and historically homogeneous population from Calabria, a south Italian region. A screening performed on 24 patients from unrelated families highlighted the high prevalence of a 5083del19 alteration in the BRCA1 gene, which accounts for 33% of the overall gene mutations. The same mutation was also detected in 4 patients, all of Calabrian origin, referred to us by research centres from the north of Italy. Allelotype analysis, performed on probands and unaffected family members revealed the presence a common allele, therefore suggesting a founder effect due to a common ancestor. Our findings underscore the importance of ethnic background homogeneity in patients' selection and highlight the usefulness of founder mutations as a potential tool for optimisation of preclinical diagnosis in gene carriers and therapeutic approaches in affected individuals.
AIMS/HYPOTHESIS: Using primary cultures of human pancreatic islets, purified human pancreatic beta cells and the mouse beta TC6-F7 cell line, we analysed the expression of nerve growth factor, (NGF/NGF) receptors in beta cells. To investigate whether NGF could sub-serve an autocrine antiapoptotic role in beta cells, we studied the effects of NGF withdrawal using a neutralizing monoclonal anti-NGF antibody. METHODS: The expression of NGF and NGF receptors (gp140(Trk-A) and p75(NTR)) were analysed by RT-PCR and immunofluorescence. Pulse-chase experiments and beta cell/PC12 co-cultures were used to investigate NGF production and secretion from beta cells. Possible apoptosis induced by NGF withdrawal was monitored by phosphatidylserine translocation, nucleosomal formation, DNA laddering and FACS analysis. Involvement of transcription/translation mechanisms were investigated as well as the gp140(Trk-A) required. Finally, signal transduction pathways typically involved in apoptotic mechanisms were analysed by western blot analysis. RESULTS: We show that NGF and both NGF receptors, gp140(Trk-A) and p75(NTR) are expressed in beta cells where NGF is produced and secreted in a biologically active form. NGF-withdrawal induces beta-cell transcription/translation independent apoptosis but mediated by gp140(Trk-A). Analysis of signal transduction pathways revealed that NGF withdrawal inhibits the PI3-K, protein kinase B (AKT), Bad survival pathway and activates c-Jun kinase (JNK) whereas ERKs and p38 mitogen-activated protein kinase (MAPK) are not affected. Moreover, Bcl-XL, but not Bcl-2 protein expression are reduced. CONCLUSION/INTERPRETATION: We suggest that the integrity of the NGF/NGF receptor system and NGF bioavailability participate in controlling beta-cell survival in culture which represents a key issue for improving possibilities for transplantations in the treatment of diabetes.
Explore the source record for details and available documents.
Autoantibodies directed against human CD38 (an enzyme catalysing the interconversion of NAD(+) and cyclic ADP-ribose) have been demonstrated recently in patients with type 2 diabetes. We tested 220 consecutive Caucasian patients with autoimmune chronic thyroiditis, 104 patients with Graves' disease, 220 subjects from the general population (control I) and 78 healthy control subjects not affected by thyroid autoimmune disorders (control II) for the presence of anti-CD38 autoimmunity. Using Western blot analysis and optical densitometry, a specific band corresponding to human recombinant CD38 was identified in the serum of several subjects. By defining anti-CD38 positivity as a standardized optical reading > 3 s.d. higher than the mean value of control I, 10.4% of patients with thyroiditis and 7.7% of Graves' patients were anti-CD38 positive (P = 0.0009 versus 1.8% of control I). Similarly, 13.1% of patients with thyroiditis and 10.5% of Graves' patients had a standardized optical reading > 3 s.d. higher than the mean value of the subjects not affected by thyroid autoimmune disorders (P = 0.002 versus 1.2% of control II). Anti-CD38 autoimmunity did not differ between euthyroid, hyperthyroid or hypothyroid patients or between patients with or without thyroid hypoechogenicity. Anti-CD38 autoantibodies were associated with higher levels of circulating antithyroid-peroxidase antibodies (P = 0.03) and they were more frequent in Graves' patients with ophthalmopathy (P < 0.05). Anti-CD38 autoantibodies are a new autoimmune marker in chronic autoimmune thyroiditis and Graves' disease. The specific role of CD38 and its autoantibodies in the modulation of thyroid cell function or growth remains to be investigated.
Endotoxin is one of the major factors causing myocardial depression and death during sepsis in humans. Recently, it was reported that endotoxin may induce cardiomyocyte apoptosis. Also, multiple caspase activation has been implicated in endotoxin-induced apoptosis in several organ systems. In this study, we investigated whether endotoxin would increase myocardial caspase activities and evaluated the effects of in vivo administration (3 mg/kg) of the broad-spectrum caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone(z-VAD.fmk), the caspase-3-like inhibitor benzyloxycarbonyl-Asp-Glu-Val-Asp-chloromethylketone (z-DEVD.cmk), and the caspase-1-like inhibitor acetyl-Tyr-Val-Ala-Asp-chloromethylketone (Ac-YVAD. fmk), on endotoxin-induced myocardial dysfunction and apoptosis. Endotoxin administration (10 mg/kg iv) induced myocardial contractile dysfunction that was associated with caspase activity increases and nuclear apoptosis. Broad-spectrum z-VAD.fmk and z-DEVD.cmk improved endotoxin-induced myocardial dysfunction and reduced caspase activation and nuclear apoptosis when given immediately and 2 h after endotoxin. In contrast, no effects of Ac-YVAD.fmk were observed on myocardial function and caspase-induced apoptosis. Administration of caspase inhibitors 4 h after endotoxin treatment was not able to protect the rat heart from myocardial dysfunction and nuclear apoptosis. These observations provide evidence that in our model, caspase activation plays a role in endotoxin-induced myocardial apoptosis. Caspase inhibition strategy may represent a therapeutic approach to endotoxin-induced myocardial dysfunction.
Despite intensive therapy, severe septic shock is commonly associated with myocardial dysfunction and death in humans. No new therapies have proven efficiency against cardiovascular alterations in sepsis. Here, we addressed the question of a beneficial effect of pharmacological inhibition of caspases on myocardial dysfunction following endotoxin treatment. Hearts from rats treated with endotoxin (10 mg/kg, intravenously) were isolated 4 h posttreatment for analysis. Assessment of myocardial contractility ex vivo and detection of apoptosis were performed. Hearts from endotoxin-treated rats displayed multiple caspase activities and also typical apoptosis pattern as detected by TUNEL, DNA fragmentation assays, and cytochrome c release as compared with control rats. z-VAD.fmk (3 mg/kg, intravenously), a broad spectrum caspase inhibitor (but not the irrelevant peptide z-FA.fmk), in coinjection with endotoxin, not only reduced caspase activities and nuclear apoptosis but also completely prevented endotoxin-induced myocardial dysfunction evaluated 4 h and even 14 h after endotoxin challenge. These data indicate that caspase activation plays an important role in myocardial cell dysfunction. Moreover, these results suggest that inhibitors of caspases may have important therapeutic applications in sepsis.
Studies in rodents have suggested that Th2 and Th3 cytokines can be effective in reducing proinflammatory and Th1 cytokine-induced islet damage. Whether this is the case with human islets and might be due to a direct action of Th2 and Th3 cytokines is not known. In the present study, we evaluated whether Th2 (500 U/ml IL-4 plus 100 U/ml IL-10) or Th3 (5 ng/ml TGF-1beta) cytokines may prevent the derangements induced on isolated human islets by prolonged (12 or 72 h) exposure to combined proinflammatory (50 U/ml IL-1beta, 1000 U/ml TNF alpha) and Th1 (1000 U/ml interferon gamma) cytokines. Compared with control islets, cells preincubated for 12 or 72 h with proinflammatory and Th1 cytokines showed a significant decrease of glucose-stimulated insulin secretion and a significant increase of nitrites production. The addition of IL-4 plus IL-10 or TGF-1beta in the medium prevented these cytostatic effects in the 12-h incubation experiments, but not after the 72-h exposure period. IL-1beta, interferon gamma, and TNF alpha caused no major change in either islet cell survival or Bcl-2 and Bax mRNA expression after a 12-h incubation; however, a marked increase in the amount of dead cells, with a major decrease of Bcl-2 mRNA expression, was observed after 72 h. The presence of Th2, but not of Th3, cytokines significantly reduced beta-cell death, without any major effect on Bcl-2 and Bax mRNA expression. These results suggest that Th2 and (at lower extent) Th3 cytokines may have a partial, direct protective effect on isolated human islets exposed to the cytostatic and cytotoxic action of proinflammatory and Th1 cytokines.