Cystic gastrointestinal stromal tumors of the pancreas simulating cystoadenocarcinoma. Report of three cases and short review of the literature.

Gastrointestinal stromal tumors (GISTs) represent a distinct subset of mesenchymal tumours of the gastrointestinal tract. They are more common in the stomach and small intestine, and are characterized by the proliferation of spindle or epithelioid cells and by the expression of CD117. Extra-gastrointestinal stromal tumors are rare and only 13 cases of pancreatic GISTs have been reported in the literature, only 1 of which presented as a cystic lesion. Mutational analysis of KIT and Platelet derived growth factor receptor-α genes was performed only in two out of the 13 cases. We report 3 cases of cystic GISTs of the pancreas, radiologically mimicking a cystoadenocarcinoma. Routine histopathology and molecular characterization of the tumours have been performed. In two of them, molecular analysis showed unusual genetic alterations (the internal repeat of codon 502 and 503 in exon 9 of the KIT gene and the KIT exon 9 single nucleotide substitution c.1427G⟩T). Pancreatic GIST should be included in the differential diagnosis of both cystic and solid masses of the pancreas. The diagnosis should be accomplished by a combination of radiology, histology, immunohistochemistry and molecular biology. The evaluation of CD117 expression and the sequence analysis of KIT and Platelet derived growth factor receptor-α gene is mandatory for therapy.

Immunolocalisation of ghrelin and obestatin in human testis, seminal vesicles, prostate and spermatozoa.

The role of ghrelin and obestatin in male reproduction has not completely been clarified. We explored ghrelin and obestatin localisation in the male reproductive system. Polyclonal antibodies anti-ghrelin and anti-obestatin were used to detect the expression of these hormones in human testis, prostate and seminal vesicles by immunocytochemistry, while in ejaculated and swim up selected spermatozoa by immunofluorescence. Sertoli cells were positive for both peptides and Leydig cells for ghrelin; germ cells were negative for both hormones. Mild signals for ghrelin and obestatin were observed in rete testis; efferent ductules were the most immune reactive region for both peptides. Epididymis was moderately positive for ghrelin; vas deferens and seminal vesicles showed intense obestatin and moderate ghrelin labelling; prostate tissue expressed obestatin alone. Ejaculated and selected spermatozoa were positive for both peptides in different head and tail regions. This study confirms ghrelin localisation in Leydig and Sertoli cells; the finding that ghrelin is expressed in rete testis, epididymis, vas deferens and seminal vesicles is novel, as well as the localisation of obestatin in almost all tracts of the male reproductive system. This research could offer insights for stimulating other studies, particularly on the role of obestatin in sperm physiology, which is still obscure.

Cell response to oxidative stress induced apoptosis in patients with Leber's hereditary optic neuropathy.

OBJECTIVES: Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease in which acute or subacute bilateral visual loss occurs preferentially in young men. Over 95% of LHON cases are associated with one of three mitochondrial DNA (mtDNA) point mutations, but only 50% of men and 10% of women who harbour a pathogenetic mtDNA mutation develop optic neuropathy. This incomplete penetrance and preference for men suggests that additional genetic (nuclear or mitochondrial) and/or environmental factors must modulate phenotype expression in LHON. A role for reactive oxygen species (ROS) in mitochondrial diseases, secondary to mtDNA mutations, or as a result of the direct effect of ROS cytotoxicity, has been implicated in many mitochondrial disorders, including LHON. The purpose of this study was to investigate the role of oxidative stress induced apoptosis in LHON. METHODS: The 2-deoxy-D-ribose induced apoptotic response of peripheral blood lymphocytes from six patients with LHON and six healthy subjects was investigated using light microscopy, flow cytometry, agarose gel electrophoresis, and the measurement of mitochondrial membrane potential. RESULTS: Cells of patients with LHON had a higher rate of apoptosis than those of controls and there was evidence of mitochondrial involvement in the activation of the apoptotic cascade. CONCLUSIONS: These differences in oxidative stress induced apoptosis are in line with the hypothesis that redox homeostasis could play a role in the expression of genetic mutations in different individuals and could represent a potential target in the development of new therapeutic strategies.

DNA end labelling (TUNEL) in a 3 year old girl with Leigh syndrome and prevalent cortical involvement.

Neuropathological study of a 3 1/2 year old girl with familial Leigh syndrome who also harboured a rare ATPase gene mutation disclosed extensive and unusual lesions in the cerebral cortex, despite a typical histological pattern. Early lesions in the periacqueductal grey matter of the brainstem, characterised by capillary congestion and initial regressive neuronal changes, were also observed, along with TUNEL reactive neuronal cells showing morphological signs typical of apoptosis in cortical areas with neuronal cell loss. The finding of lesions in atypical brain areas and for the first time, very early regressive neuronal phenomena, suggest that early changes in crucial brain areas may have been a cause of death. The abundance of TUNEL positive nuclei in cortical areas in the present case suggests that the apoptosis may be involved in the mechanism of neuronal death in Leigh syndrome.

Expression of macrophage migration inhibitory factor in diffuse systemic sclerosis.

OBJECTIVE: To evaluate whether, in patients with the diffuse form of systemic sclerosis (dSSc), macrophage migration inhibitory factor (MIF) production is dysregulated. METHODS: 10 patients with dSSc and 10 healthy controls, matched for age and sex, were studied. MIF expression was evaluated by immunohistochemistry on formalin fixed skin biopsies of patients with dSSc and controls. MIF levels were assayed in the sera and in the supernatants of skin cultured fibroblasts by a colorimetric sandwich enzyme linked immunosorbent assay (ELISA). MIF concentrations in culture medium samples and in serum samples were compared by Student's two tailed t test for unpaired data. RESULTS: Anti-MIF antibody immunostained the basal and mainly suprabasal keratinocytes. Small perivascular clusters of infiltrating mononuclear cells were positive; scattered spindle fibroblast-like cells were immunostained in superficial and deep dermal layers. The serum concentrations of MIF in patients with dSSc (mean (SD) 10705.6 (9311) pg/ml) were significantly higher than in controls (2157.5 (1288.6) pg/ml; p=0.011); MIF levels from dSSc fibroblast cultures (mean (SD) 1.74 (0.16) ng/2 x 10(5) cells) were also significantly higher than in controls (0.6 (0.2) ng/2 x 10(5) cells; p=0.008). CONCLUSION: These results suggest that MIF may be involved in the amplifying proinflammatory loop leading to scleroderma tissue remodelling.

Interferons and their receptors in human papillomavirus lesions of the uterine cervix.

PURPOSE OF INVESTIGATION: In this study we analyzed the immunohistochemical expression of specific types of interferon (IFN) in human papillomavirus (HPV) associated cervical lesions. METHODS: Reactivity to anti-IFN-alpha,-beta and -gamma and to anti-IFN-alpha/beta- and gamma-receptors was tested in 33 cervical punch biopsies from 24 HPV-infected women and nine healthy controls. The HPV-infected cases were subdivided into low-risk and high-risk groups, according to the known "oncogenic" potential of the HPV-types detected by PCR. RESULTS: Cervical epithelium and stroma in HPV-negative as well as low-risk HPV-positive samples were diffusely stained by anti IFN-alpha, beta and gamma antibodies. In contrast, a significantly lower percentage of high-risk HPV-infected tissues was immunoreactive to IFN-beta in the stroma and IFN-gamma in the epithelium. There were no relevant differences between control and HPV cases in the expression of IFN-receptors. CONCLUSION: We show that a decreased production of some specific classes of IFN is associated with high-risk-type HPV lesions suggesting an important role of IFN distribution patterns in the pathogenesis of HPV lesions.

Macrophage migration inhibitory factor in the human endometrium: expression and localization during the menstrual cycle and early pregnancy.

Macrophage migration inhibitory factor (MIF) was discovered as an activated T-lymphocyte-derived protein that inhibits the random migration of macrophages in vitro. Subsequently, knowledge of the physiological actions of MIF was extended to include its role as a proinflammatory cytokine that affects several functions of macrophages and lymphocytes. Previous reports have suggested an involvement of MIF in reproduction. However, no data are currently available on the presence of this cytokine in the human endometrium. In this study, the expression and tissue localization of MIF was evaluated in specimens of cycling endometrium, first trimester placenta bed biopsy, and isolated endometrial glands by Western blot analysis, immunohistochemistry, ELISA, and reverse transcription-polymerase chain reaction. The results demonstrated that MIF is expressed in human endometrium across the menstrual cycle and in early pregnancy. Immunohistochemical localization identified the protein in glandular epithelium, in stromal and predecidualized stromal cells of cycling endometrium, as well as in the decidua of first-trimester placenta. The proinflammatory features and specific actions of MIF on lymphoid cells suggest its potential involvement in several aspects of endometrial physiology.

Altered glutathione anti-oxidant metabolism during tumor progression in human renal-cell carcinoma.

It has been proposed that oxidative stress develops in tumors, with important consequences for growth and progression. To investigate this hypothesis, we measured low m.w. thiols, disulfides, protein-mixed disulfides and a pool of major anti-oxidant enzymes in renal-cortex as well as renal-cell carcinoma (RCC) specimens at stages I-II and III. Our data showed (i) a significant increase in the levels of total intracellular glutathione at both tumor stages (levels were 2.6-2.8 fold higher than those in the normal renal cortex), (ii) a marked lowering of the GSH/GSSG ratio in stage I-II accompanied by a significant decrease of many GSH-dependent enzymes (i.e., GPX, GST, GGT, GR) and (iii) unchanged GSH/GSSG ratio and GSH-dependent enzyme activity in stage III with respect to normal renal cortex. These results indicate that relevant variations exist in the glutathione antioxidant system in the different stages of RCC and support the hypothesis that oxidative stress plays an important role in RCC growth and progression.

Thymic hyperplasia and lung carcinomas in a line of mice transgenic for keratin 5-driven HPV16 E6/E7 oncogenes.

Human Papillomavirus type 16 (HPV-16) is the cause of both benign lesions and ano-genital cancers. In HPV-associated cancers the transforming properties of the expressed viral E6 and E7 proteins have been revealed by a number of different assays. We have generated transgenic mice expressing HPV-16 E6/E7 genes under the control of the murine keratin 5 gene promoter, which should confer cell-type specific expression in the basal cells of squamous stratified epithelia. Transgenic mice developed thymic hyperplasia and lung neoplasia with 100% frequency, the thymus showing a size increase at 2 months and reaching the maximum dimension at 6 months, when lung carcinomas appeared. After this time the size of hyperplastic thymi decreased, while malignant formations invaded the mediastinal area. Hepatic metastasis could be also observed in some of the animals at the autopsy and death invariably occurred around 10-11 months of age.

Enhanced 2-deoxy-D-ribose-induced-apoptosis, a phenotype of lymphocytes from old donors, is not observed in the Werner syndrome.

Werner syndrome (WS) is an inherited disease characterized by the premature appearance of features of normal aging in young adults. To evaluate the relationship between Werner syndrome and aging, we analyzed the apoptotic response of peripheral blood lymphocytes (PBLs) from two WS patients (mean age 34 years old) incubated with 2-deoxy-D-ribose (dRib), a reducing sugar that induces apoptosis in quiescent cells through an oxidative stress; the results have been compared to two control groups (mean age 35 and 83 years old, respectively). The presence of apoptotic cells was detected by light microscopy, flow cytometry, and agarose gel electrophoresis. In all three groups an increased time-dependent apoptotic response was evident, but the apoptotic response to dRib was lower in WS's cells than in cells from age-matched controls and less than in cells from older subjects. Our results confirm a low susceptibility of WS cells to DNA damaging agents as dRib and suggest that the pathogenic mechanisms underlying normal cellular aging and WS's cellular senescence may be different.

Microcystic adenoma of the pancreas (glycogen-rich cystadenoma) with stromal amyloid deposits.

AIMS: We report a case of a pancreatic glycogen-rich microcystic serous adenoma with stromal amyloid deposits, focusing on the significance of isolated amyloid deposits in tumours. METHODS AND RESULTS: The architectural pattern was characterized by thin-walled cysts lined by a single layer of flat or cuboidal epithelial cells intensely stained by the PAS-reaction only before diastase digestion, suggesting the presence of glycogen. Tumour stroma was composed of broad fibrocollagenous tissue with lamellar hyalinized areas which were positively stained by Congo red and showed green birefringence and dichroism with polarized light. For amyloid protein characterization, immunohistochemical studies were performed with anti-beta amyloid protein and anti-amyloid precursor pre-A4695. The former antibody diffusely stained tumour stroma, while the latter stained only scattered stroma cells. CONCLUSIONS: This is the first documented case of amyloid deposition in pancreatic serous adenoma. We indicate that the source of amyloid is an APP-like precursor secreted by stromal myofibroblasts.

Macrophage migration inhibitory factor in prostatic adenocarcinoma: correlation with tumor grading and combination endocrine treatment-related changes.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a ubiquitary cytokine whose expression has been investigated in tumors, showing a correlation between tumor aggressiveness and production of this protein by neoplastic cells. The aim of our study was to correlate MIF expression with tumor grade (Gleason scoring system) and histopathological changes after combined endocrine treatment (CET) of prostate adenocarcinoma. METHODS: We analyzed MIF immunoreactivity in 124 paired needle biopsies and radical prostatectomy specimens from 62 prostate cancer patients, of which 20 had been treated with CET. RESULTS: In untreated prostates, MIF expression significantly correlated with tumor grading, being stronger in low-grade than in high-grade adenocarcinoma. In treated prostates, histopathological changes also correlated with MIF immunoreactivity, but not in a significant manner. CONCLUSIONS: The results of the current study demonstrated that with histological dedifferentiation, prostate adenocarcinoma cells show a reduced MIF expression. This finding may be the consequence of a reduced MIF synthesis or the result of an enhanced and altered secretion by tumor cells into the surrounding stroma. The consequent abnormal interaction between MIF and environmental factors might influence tumor growth and diffusion. On the other hand, the minor but not significantly reduced MIF expression by tumor cells after CET seems to exclude a hormonal regulation of MIF secretion.

Apoptotic response and cell cycle transition in ataxia telangiectasia cells exposed to oxidative stress.

The recently identified ATM gene plays a role in a signal transduction network activating multiple cellular functions in response to DNA damage. An attractive hypothesis is that the ATM protein is involved in a specialized antioxidant system responsible for detoxifying reactive oxygen intermediate and that the absence or dysfunction of this protein in AT cells would render them less capable of dealing with oxidative stress. In order to investigate the role of the ATM gene in cell cycle control and programmed cell death, Lymphoblastoid cell lines derived from four Ataxia-Telangiectasia (AT) patients and six controls have been analyzed. All cell lines were incubated with 2-deoxy-D-ribose (dRib), a reducing sugar that induces apoptosis through oxidative stress. The result showed an impaired response to dRib-induced apoptosis in AT cells, as well as a defect of cellular cycle arrest in G1/S phase and a normal expression of p53 protein. This indicate that the kinase activity of ATM gene product plays a very important role in the cellular response to oxidative stress. In conclusion the altered response of AT cells to oxidative stress and particularly their resistance to apoptotic cell death, could explain the high predisposition of these cells to progress toward malignant transformation.

DNA/nuclear protein content in the evaluation of cell cycle modifications during colon carcinogenesis.

OBJECTIVE: To investigate the colorectal adenomacarcinoma sequence by biparametric DNA/nuclear protein flow cytometry with the aim of evaluating cell cycle modifications during carcinogenesis. STUDY DESIGN: Paraffin-embedded specimens of 27 adenomas with mild/moderate dysplasia, 20 adenomas with severe dysplasia/intramucosal adenocarcinomas, 28 adenocarcinomas and 14 normal colon mucosa specimens were analyzed by biparametric DNA/nuclear protein content flow cytometric analysis in order to evaluate cell cycle modifications during colorectal carcinogenesis. RESULTS: The mean G0-G1A fraction of the cell cycle was 50.6% (SD +/- 17.2), 25.7% (SD +/- 15.1), 27.8% (SD +/- 11.7) and 29% (SD +/- 13.8) for normal mucosa, adenomas with mild/moderate dysplasia, adenomas with severe dysplasia and adenocarcinomas, respectively. The difference between normal mucosa and the other groups was statistically significant (P < .05), while no significant differences were detectable between adenomas with different degrees of dysplasia and adenocarcinomas. CONCLUSION: Our results show a decrease in G0-G1A in adenomas with mild/moderate dysplasia, suggesting that modification of the cell cycle may represent an early step in colon carcinogenesis, and they support the hypothesis that disregulation of cell cycle-controlling genes is an early event in the adenoma-carcinoma sequence.

Vitamin E serum levels and gastric cancer: results from a cohort of patients in Tuscany, Italy.

Alpha-tocopherol has been reported to play an important role against oxidative damage and in the inhibition of cell transforming and mutagenesis. We analysed vitamin E serum levels in 51 cases of patients affected by gastric cancer at different stages of the disease, and in 49 age-matched controls. All patients had normal values of alpha-tocopherol. However, when patients have been grouped according to histotype of gastric lesions, a significant vitamin E increase has been found in diffuse gastric cancer histotype compared to the intestinal histotype. Our results suggest that a correlation between vitamin E serum levels and gastric cancer histotype should be considered.

Charge heterogeneity of macrophage migration inhibitory factor (MIF) in human liver and breast tissue.

Macrophage migration inhibitory factor (MIF) is an ubiquitous protein playing various immunological and hormonal roles. Theoretical electrophoretic coordinates calculated from protein sequence in the SWISS-PROT database (AC P14174) are 12 kDa and pI 8.24. Using two-dimensional (2-D) immunoblotting, we have detected isoelectric forms at ca. 11.9 kDa, with pI values of 7.8 and 6.98 in human liver tissue, breast tissue and a cell line and in preparations of human MIF expressed in E. coli. This evidence suggests that MIF charge heterogeneity originates from a post-translational modification not requiring eukaryote-specific enzymes. We have also detected in human liver a minor immunoreactive spot at pI 6.23, which coincides with the MIF spot in the liver map in SWISS-2DPAGE. The pI 6.23 isoform also conceivably derives from post-translational modification, as MIF is known to be encoded in the human genome by a single copy gene.

Villous adenoma of the bladder.

Villous adenomas of the bladder are rare tumors and up to now they have not been seen to undergo malignant transformation. We report a case of villous adenoma of the bladder with areas of adenocarcinoma in a 72-year-old man. We describe all the morphological, histochemical and immunohistochemical features characterizing this tumor. We recommend adequate pathological sampling and a thorough follow-up of patients with villous adenoma. The prognosis and the behaviour of these adenomatous papillary lesions, morphologically similar to colonic adenomas, in the bladder is unclear. We report a case with focal area of adenocarcinoma and review the literature.