Search results for "COLON"
showing 10 items of 2038 documents
γδ T cells as a potential tool in colon cancer immunotherapy
2014
γδ T cells are capable of recognizing tumor cells and exert potent cellular cytotoxicity against a large range of tumors, including colon cancer. However, tumors utilize numerous strategies to escape recognition or killing by patrolling γδ T cells, such a downregulation of NKG2D ligands, MICA/B and ULBPs. Therefore, the combined upregulation of T-cell receptorand NKG2D ligands on tumor cells and induction of NKG2D expression on γδ T cells may greatly enhance tumor killing and unlock the functions of γδ T cells. Here, we briefly review current data on the mechanisms of γδ T-cell recognition and killing of colon cancer cells and propose that γδ T cells may represent a promising target for the…
Efficient killing of human colon cancer stem cells by gammadelta T lymphocytes
2009
Colon cancer comprises a small population of cancer stem cells (CSC) that is responsible for tumor maintenance and resistant to cancer therapies, possibly allowing for tumor recapitulation once treatment stops. We previously demonstrated that such chemoresistance is mediated by autocrine production of IL-4 through the up-regulation of antiapoptotic proteins. Several innate and adaptive immune effector cells allow for the recognition and destruction of cancer precursors before they constitute the tumor mass. However, cellular immune-based therapies have not been experimented yet in the population of CSCs. Here, we show that the bisphosphonate zoledronate sensitizes colon CSCs to Vgamma9Vdelt…
Human NK cells selective targeting of colon cancer-initiating cells: a role for natural cytotoxicity receptors and MHC class I molecules
2013
Abstract Tumor cell populations have been recently proposed to be composed of two compartments: tumor-initiating cells characterized by a slow and asymmetrical growth, and the “differentiated” cancer cells with a fast and symmetrical growth. Cancer stem cells or cancer-initiating cells (CICs) play a crucial role in tumor recurrence. The resistance of CICs to drugs and irradiation often allows them to survive traditional therapy. NK cells are potent cytotoxic lymphocytes that can recognize tumor cells. In this study, we have analyzed the NK cell recognition of tumor target cells derived from the two cancer cell compartments of colon adenocarcinoma lesions. Our data demonstrate that freshly p…
Comparative Antitumor Effect of Preventive versus Therapeutic Vaccines Employing B16 Melanoma Cells Genetically Modified to Express GM-CSF and B7.2 i…
2012
Cancer vaccines have always been a subject of gene therapy research. One of the most successful approaches has been working with genetically modified tumor cells. In this study, we describe our approach to achieving an immune response against a murine melanoma model, employing B16 tumor cells expressing GM-CSF and B7.2. Wild B16 cells were injected in C57BL6 mice to cause the tumor. Irradiated B16 cells transfected with GM-CSF, B7.2, or both, were processed as a preventive and therapeutic vaccination. Tumor volumes were measured and survival curves were obtained. Blood samples were taken from mice, and IgGs of each treatment group were also measured. The regulatory T cells (Treg) o…
Functional Inactivation of pRB Results in Aneuploid Mammalian Cells After Release From a Mitotic Block
2002
AbstractThe widespread chromosome instability observed in tumors and in early stage carcinomas suggests that aneuploidy could be a prerequisite for cellular transformation and tumor initiation. Defects in tumor suppressers and genes that are part of mitotic checkpoints are likely candidates for the aneuploid phenotype. By using flow cytometric, cytogenetic, immunocytochemistry techniques we investigated whether pRB deficiency could drive perpetual aneuploidy in normal human and mouse fibroblasts after mitotic checkpoint challenge by microtubule-destabilizing drugs. Both mouse and human pRB-deficient primary fibroblasts resulted, upon release from a mitotic block, in proliferating aneuploid …
Genomic instability induced by α-pinene in Chinese hamster cell line.
2012
Here, we report the effects of exposure of mammalian cells to α-pinene, a bicyclic monoterpene used in insecticides, solvents and perfumes. Morphological analysis, performed in V79-Cl3 cells exposed for 1 h to increasing concentrations (25 up to 50 μM) of α-pinene, indicated a statistically significant increase in micronucleated and multinucleated cell frequencies; apoptotic cells were seen at 40 and 50 μM. This monoterpene caused genomic instability by interfering with mitotic process; in fact, 50% of cells (versus 19% of control cells) showed irregular mitosis with multipolar or incorrectly localised spindles. Cytogenetic analysis demonstrated high-frequency hypodiploid metaphases as well…
Quantification of Listeria monocytogenes in salads by real time quantitative PCR
2005
Abstract A real time quantitative PCR (RTQ-PCR) was carried out purifying DNA extracts of Listeria monocytogenes using a High Pure Listeria Sample Preparation Kit and quantifying in a LightCycler system with hybridisation probes. A standard curve was constructed with serial dilutions. A range linear relationship, from 10 to 10 5 L. monocytogenes colony forming units (CFU), was observed between threshold cycle ( C t ) and logarithmic concentration of the serial dilutions. The assay was linear in a range from 10 to 10 5 L. monocytogenes CFU and the coefficient of determination ( r 2 ) was > 0.98. RTQ-PCR presented an efficiency of > 85%. The accuracy of the PCR-based assay, expressed as % bia…
In situ activity of a bacteriocin-producing Lactococcus lactis strain. Influence on the interactions between lactic acid bacteria during sourdough fe…
2005
Aims: To biochemically characterize the bacteriocin produced by Lactococcus lactis ssp. lactis M30 and demonstrate its effect on lactic acid bacteria (LAB) during sourdough propagation. Methods and Results: A two-peptide bacteriocin produced by L. lactis ssp. lactis M30 was purified by ion exchange, hydrophobic interaction and reversed phase chromatography. Mass spectrometry of the two peptides and sequence analysis of the ltnA2 gene showed that the bacteriocin was almost identical to lacticin 3147. During a 20-day period of sourdough propagation the stability of L. lactis M30 was demonstrated, with concomitant inhibition of the indicator strain Lactobacillus plantarum 20, as well as the …
A taxonomic survey of lactic acid bacteria isolated from wheat (Triticum durum) kernels and non-conventional flours
2007
In order to explore the correspondence between raw material- and mature sourdough-lactic acid bacterial (LAB) communities, 59 Italian wheat (Triticum durum) grain samples, one bran and six non-conventional flour samples were analyzed through a culture-dependent approach. The highest cell count by an agar medium specific for LAB was 2.16 log CFU/g. From about 2300 presumptive LAB (Gram-positive and catalase-negative) colonies collected, a total of 356 isolates were subjected to identification by a genetic polyphasic strategy consisting of RAPD-PCR analysis, partial 16S rRNA gene sequencing, species-specific and multiplex PCRs. The isolates were recognized as 137 strains belonging to Aerococc…
PCR-DGGE fingerprints of microbial succession during a manufacture of traditional water buffalo mozzarella cheese.
2004
D . E R C O L I N I , G . M A U R I E L L O , G . B L A I O T T A , G . M O S C H E T T I A N D S . C O P P O L A . 2003. Aims: To monitor the process and the starter effectiveness recording a series of fingerprints of the microbial diversity occurring at different steps of mozzarella cheese manufacture and to investigate the involvement of the natural starter to the achievement of the final product. Methods and Results: Samples of raw milk, natural whey culture (NWC) used as starter, curd after ripening and final product were collected during a mozzarella cheese manufacture. Total microbial DNA was directly extracted from the dairy samples as well as bulk colonies collected from the plates…