Effects of inducible overexpression of DNp73alpha on cancer cell growth and response to treatment in vitro and in vivo.

The p73 gene has a complex regulation, which leads to the expression of different isoforms, often with opposite biological effects. We have generated in the human colocarcinoma cell line HCT116, expressing a wild-type p53, an inducible DNp73alpha expressing system. Two clones (HCT116/DN3 and HCT116/DN14), upon doxycycline addition, show a strong expression of DNp73alpha. In vitro the two DNp73alpha overexpressing clones grow at similar rate of the control transfected clone (HCT116/8a) and similarly respond to DNA damage. When injected in mice, HCT116/DN3, HCT116/DN14, and HCT116/8a cells grew similarly in the absence or presence of tetracycline. In HCT116/DN3 and HCT116/DN14 tumors, tetracycline induced a strong expression of DNp73alpha both as mRNA and protein. These results indicate that in this system the overexpression of the DNp73alpha does not induce a more aggressive phenotype and does not seem to be associated with a reduced response of the cells to treatment with anticancer agents.

Trail activity in human ovarian cancer cells: potentiation of the action of cytotoxic drugs.

The ability of the TRAIL ligand to induce cell killing in three ovarian cancer cell lines was investigated using a glutathione-S-transferase (GST)-TRAIL fusion protein. One of the three lines was sensitive to TRAIL, which induced cell killing in a range of concentrations similar to those necessary to kill the TRAIL-sensitive leukaemic cell line Jurkat. The relative mRNA expression of the four TRAIL receptors did not explain the different sensitivities of the three ovarian cancer cell lines to TRAIL treatment. The TRAIL-sensitive IGROV-1 cell line expressed slightly lower levels of the anti-apoptotic protein FLIP than the two TRAIL-insensitive cell lines (A2780 and SKOV-3). Nevertheless, although TRAIL did not significantly reduce cell growth in the A2780 and SKOV-3 cells it did enhance the activity of paclitaxel and cisplatin (DDP), the two most widely used drugs for the treatment of ovarian cancer, increasing their ability to induce apoptosis. The use of TRAIL in combination with classical anticancer agents might thus boost the apoptotic response, improving the activity of DDP and paclitaxel in ovarian cancer.

Microsatellite instability and genetic alterations in ovarian cancer.

Inactivation of the mismatch repair system (MMR) leads to the accumulation of mutations, particularly in highly repeated sequences (microsatellite). The resulting microsatellite instability can profoundly affect the cellular behaviour, since many genes playing important roles in the mechanisms of signal transduction, apoptosis, DNA repair and cell cycle control can be altered in tumors presenting microsatellite instability. Germline mutations in MMR genes are associated with hereditary non polyposis colon cancer. Microsatellite instability and the associated frameshift mutations in genes have been well described in sporadic colon, gastric and endometrium tumors. In this review we collected the data available on the impact of microsatellite instability in ovarian cancer and the possible consequences of this instability to the presence of mutations in genes containing in their coding regions repeated nucleotides and to the response of these tumors to chemotherapy.

Laparoscopic treatment of post-hysterectomy colovaginal fistula in diverticular disease. Case report.

Colonic diverticular disease is a benign condition typical of the Western world, but it is not rare for even the 1st episode of diverticulitis to carry potentially fatal complications. The evolution of a peridiverticular process generally poses problems for medical treatment and exposes patients to repeated episodes of diverticulitis, making surgical treatment necessary in approximately 30% of symptomatic patients. One of the most worrying complications of diverticulosis is internal fistula. The most common types of fistula are colovesical and colovaginal, against which the uterus can act as an important protective factor. The symptoms and the clinical and instrumental management of patients with diverticular fistulas are much the same as for patients with episodes of acute diverticulitis. Staging of the disease (according to Hinchey) should be done promptly so that the necessary action can be taken prior to surgery, implementing total parenteral nutrition (TPN), nasogastric aspiration and broad-spectrum antibiotic treatment. The best surgical approach to adopt in patients with diverticulitis complicated by fistula is still not entirely clear, though the 3-step strategy is currently tending to be abandoned due to its high morbidity and mortality rates. There is a widespread conviction, however, that the 2-step strategy (Hartmann, or resection with protective stomy) and the 1-step alternative should be reserved, respectively, for patients in Hinchey stages 3, 4 and 1, 2 with a situation of attenuated local inflammation. The 1-step approach seems to be safe and effective. This report describes a case of colovaginal fistula in a patient with colonic diverticulosis who had recently undergone hysterectomy, but who, unlike such cases in the past, was treated in a single step using a laparoscopic technique.

IgE binding to soluble and insoluble wheat flour proteins in atopic and non-atopic patients suffering from gastrointestinal symptoms after wheat ingestion.

BACKGROUND: The involvement of IgE-mediated hypersensitivity reactions in the genesis of gastrointestinal symptoms after ingestion of foods containing wheat has been rarely reported. OBJECTIVE: To detect IgE specifically binding to wheat proteins in the sera of atopic and non-atopic patients suffering from gastrointestinal symptoms after ingestion of wheat and to evaluate the reliability of skin prick test and CAP in the diagnosis of food allergy to wheat. METHODS: The sera of patients (10 atopic and 10 non-atopic) previously diagnosed as suffering from irritable bowel syndrome and complaining of symptoms after wheat ingestion were analysed by immunoblotting for IgE binding to water/salt-soluble and insoluble wheat flour proteins. RESULTS: All the atopic patients and only one of the non-atopic patients were positive to wheat CAP. For the patients tested, skin prick test was positive for all the atopic patients and for only one of the non-atopic patients. However, immunoblotting experiments showed the presence of specific IgE to wheat proteins in all the patients. Ten out of 11 of the wheat CAP-positive patients had IgE binding to a soluble 16-kDa band, but the same band was recognized, in a slighter way, by only two out of nine of the wheat CAP-negative patients. Moreover, although almost all of the patients were negative in CAP testing with gluten, 19 out of 20 recognized protein bands belonging to the prolamin fraction. CONCLUSIONS: For the atopic patients the positivity to skin prick test and CAP to wheat was in accordance with the immunoblotting results and a food allergy to wheat could be diagnosed. In these patients a major allergen was a 16-kDa band corresponding to members of the cereal alpha-amylase/trypsin inhibitors protein family, the major allergens involved in baker's asthma. In the non-atopic patients the positive immunoblotting results contrasted with the responses of the allergologic tests, indicating that the allergenic wheat protein preparations currently used are of limited value in detecting specific IgE to wheat and that the fraction of irritable bowel syndrome (IBS) patients with food allergy may be larger than believed.