Inhibition of herpes simplex virus type 2 by vaginal lactobacilli

The protective effect of selected vaginal Lactobacillus strains (L. brevis CD2, L. salivarius FV2, L. plantarum FV9) towards herpes simplex virus type 2 (HSV-2) infection in vitro has been analyzed. Living bacterial cells affect different steps of virus multiplication. The effect on the early phases of virus infection appeared related to the bacterial adhesive potential to the cell membrane while all the strains strongly reduced intracellular events of virus multiplication. The anti HSV-2 activity was not mediated by a virucidal effect. Instead it was exerted through bacterial soluble factors able to down regulate the production of infective virions. In fact HSV-2 yield was significantly reduced in infected cells fed with cell-free supernatants of lactobacilli grown in cell culture medium. Purified lactic acid and H(2)O(2), Lactobacillus metabolites with known antimicrobial activity, produced a dose-dependent virucidal effect. Lactic acid successfully interfered with viral intracellular antigen synthesis and both the virucidal activity and the inhibition of replication were correlated to acidic pH values. L. brevis CD2, the most active strain, does not produce H(2)O(2) and neutralized lactic acid had no effect, thus indicating that factors other than H(2)O(2) and lactic acid could be responsible for the antiviral effect.

Nuclear and cytoplasmic expression of survivin in 67 surgically resected pancreatic cancer patients

Pancreatic cancer is one of the most aggressive gastrointestinal cancer with less than 10% long-term survivors. The apoptotic pathway deregulation is a postulated mechanism of carcinogenesis of this tumour. The present study investigated the prognostic role of apoptosis and apoptosis-involved proteins in a series of surgically resected pancreatic cancer patients. All patients affected by pancreatic adenocarcinoma and treated with surgical resection from 1988 to 2003 were considered for the study. Patients' clinical data and pathological tumour features were recorded. Survivin and Cox-2 expression were evaluated by immunohistochemical staining. Apoptotic cells were identified using the TUNEL method. Tumour specimen of 67 resected patients was included in the study. By univariate analysis, survival was influenced by Survivin overexpression. The nuclear Survivin overexpression was associated with better prognosis (P=0.0009), while its cytoplasmic overexpression resulted a negative prognostic factor (P=0.0127). Also, the apoptotic index was a statistically significant prognostic factor in a univariate model (P=0.0142). By a multivariate Cox regression analysis, both the nuclear (P=0.002) and cytoplasmic (P=0.040) Survivin overexpression maintained the prognostic statistical value. This is the first study reporting a statistical significant prognostic relevance of nuclear and cytoplasmic Survivin overexpression in pancreatic cancer. In particular, patients with high nuclear Survivin staining showed a longer survival, whereas patients with high cytoplasmic Survivin staining had a shorter overall survival.

Role of extracellular matrix in regulation of staurosporine-induced apoptosis in breast cancer cells

Autocrine and paracrine mechanisms modulate the synthesis and secretion of extracellular matrix (ECM); moreover, each component of the ECM is capable of modulating the synthesis and release of other ECM molecules. Therefore, the synthesis of ECM glycoprotein fibronectin and laminin was studied in the human breast cancer cell lines MCF7 and MDA MB 23, plated on different ECM. Our results showed that the cells plated on a fibronectin substrate increased laminin synthesis: this event correlated with an increase in alpha2 and alpha3 integrin subunits. Staurosporine-induced apoptosis was then analyzed in the cell lines plated on different ECM. Staurosporine treatment determined the apoptosis of 35 and 33% respectively of MDA MB 231 and MCF7; these values increased to 60 and 64% in cells plated on laminin, to 48 and 63% in cells plated on fibronectin and to 64 and 69% in cells plated on matrigel. Moreover, staurosporine treatment decreased bcl-2 expression in the cells plated on fibronectin and laminin. Yet, staurosporine treatment determined PARP cleavage and PARP partial disappearance when the cells were plated on matrigel. Finally, a partial loss of function mutant Ras protein that activated only Raf pathway, was expressed in MCF7, in order to identify whether the increase of apoptosis induced by extracellular matrix involved the Raf/MAP kinase pathway. The increase of apoptosis of the cells plated on matrigel suggested that the activation of the Raf pathway is probably involved in the decrease of survival on matrigel. These data demonstrate that the modification of ECM modulates the apoptotic process of breast cancer cells and suggest that it is worthwhile to dissect the role of ECM in the control of apoptotic process.