Search results for "colonic"
showing 10 items of 329 documents
Chemotherapy Sensitizes Colon Cancer Initiating Cells to Vγ9Vδ2 T Cell-Mediated Cytotoxicity
2013
Colon cancer comprises a small population of cancer initiating stem cells (CIC) that is responsible for tumor maintenance and resistance to anti-cancer therapies, possibly allowing for tumor recapitulation once treatment stops. Combinations of immune-based therapies with chemotherapy and other anti-tumor agents may be of significant clinical benefit in the treatment of colon cancer. However, cellular immune-based therapies have not been experimented yet in the population of colon CICs. Here, we demonstrate that treatment with low concentrations of commonly used chemotherapeutic agents, 5- fluorouracyl and doxorubicin, sensitize colon CICs to Vc9Vd2 T cell cytotoxicity. Vc9Vd2 T cell cytotox…
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…
The role of drug sequence in therapeutic selectivity of the combination of 5-fluorouracil and cis-platin.
1989
The therapeutic efficacy of 5-fluorouracil (FUra) and cis-dichlorodiamine-platinum (cis-DDP) in mice bearing transplantable leukemia and solid tumors was evaluated using different sequences of combination of these agents. The optimal sequence was cis-DDP administered 24 h after FUra. The administration of FUra at its maximally tolerated dose (MTD) followed 24 h later by low doses of cis-DDP yielded less toxicity and higher response rate against L1210 and colon 26 than the administration of these two agents in the opposite sequence or concurrently at the MTD. The sequence of administration of these two agents was not therapeutically important when the antitumor activity was evaluated against…
N-Glycosylation modification of proteins is an early marker of the enterocytic differentiation process of HT-29 cells
1990
International audience; The human colon cancer cell line HT-29 remains totally undifferentiated when glucose is present in the culture medium (HT-29 Glc+), while the same cells may undergo typical enterocytic differentiation after reaching confluence when grown in glucose-deprived medium (HT-29 Glc-). Recently, we demonstrated a deficiency in the overall N-glycan processing in confluent undifferentiated cells, whereas differentiated cells follow a classical pattern of N-glycosylation. The main changes in N-glycosylation observed in confluent undifferentiated cells may be summarised as follows: 1) the conversion of high mannose into complex glycopeptides is greatly decreased; 2) this decreas…
TGF-beta as a T cell regulator in colitis and colon cancer
2005
TGF-beta is a pleiotropic cytokine with powerful immunosuppressive functions. Mice deficient for TGF-beta1 show a dramatic phenotype with severe multiorgan inflammation and die shortly after birth. Recent investigations have highlighted the role of TGF-beta in suppression of T cell mediated autoimmune inflammation and anti-tumor immunity. In addition to its direct anti-inflammatory effects on T cells, TGF-beta has been implicated as central regulator of regulatory T cells. TGF-beta not only mediates the suppression of effector T cells by Tregs, recent evidence also reveals a role for TGF-beta along with TCR stimulation in the peripheral induction of regulatory T cells from naïve CD4+CD25- c…
Advances in endoscopic imaging of colorectal neoplasia.
2010
Colon cancer screening is arguably the most important activity performed by gastroenterologists. Recent decreases in rates of death from colorectal cancer indicate that screening methods such as colonoscopy have a positive impact. There is still room for improvement, however, particularly in prevention of right-sided colon cancer. Practice issues, such as making colonoscopy more comfortable, safer, and less costly, are keys to continued success in cancer prevention. Colonoscopy techniques, technologies, and quality control measures have advanced to improve detection, classification, and removal of early neoplasias. In particular, slow, careful inspection of the colon by gastroenterologists …
E-selectin modulates the malignant properties of T84 colon carcinoma cells.
2002
The extravasation of metastatic cells is regulated by molecular events involving the initial adhesion of tumor cells to the endothelium and subsequently the migration of cells in the host connective tissue. E-selectin on endothelial cells and sialyl Lewis X carbohydrate component on tumor cells are mainly involved in the adhesion of colon carcinoma cells to the endothelium of target organ. Interaction of T84 colon cancer cells to purified E-selectin in vitro caused an increase in the tyrosine phosphorylation of a number of proteins as well as the modulation of cellular properties correlated to the metastatic phenotype. Specifically, E-selectin-stimulated actin reorganization, increased coll…
Push-and-pull enteroscopy using a single-balloon technique for difficult colonoscopy.
2006
Background and study aims Several factors predict difficult or incomplete colonoscopy with a standard colonoscope, including female gender, low body mass index, extensive diverticulosis, and prior pelvic surgery. Patients and methods A push-and-pull enteroscopy device and a single-balloon technique was used in 14 patients (six men, eight women; mean age 62 +/- 15 years) after failure of ileocolonoscopy or endoscopic therapy using either a standard or a pediatric colonoscope. The original ileocolonoscopy had been performed to investigate colon polyps (n = 6), an obscure inflammatory process in the ileocecal region (n = 6), or iron deficiency anemia with a positive fecal occult stool test (n …