Combination therapy with venlafaxine and carbamazepine in depressive patients non-responding to venlafaxine : pharmacokinetic and clinical aspects

Résumé L'antidépresseur chiral venlafaxine (VEN) est à la fois un inhibiteur de la récapture de la sérotonine et de la noradrénaline. Le CYP2D6 et le CYP3A4 contribuent à son métabolisme stéreosélectif. Dix patients génotypés au CYP2D6 et dépressifs (F32x et F33x, ICD-10) ont participé à cette étude ouverte sur les conséquences pharmacocinétiques et pharmacodynamiques d'une « augmentation » avec la carbamazepine chez des non-répondeurs à la venlafaxine. Après une première période de traitement de quatre semaines avec VEN (195 - 52 mg/ jour), le seul patient qui présentait un déficience génétique de CYP2D6 (poor metaboliser), avait les taux plasmatiques de S-VEN et R-VEN les plus élevés, tandis que ceux de R-0-déméthyl-VEN étaient les plus bas dans ce groupe. Comme seulement 4 patients ont été des répondeurs après 4 semaines de traitement, 6 patients ont été inclus dans la deuxième période de traitement combiné VEN et carbamazépine. Cinq patients non-répondeurs ont complété cette deuxième période d'étude de quatre semaines. Chez l'unique non-répondeur au traitement combiné, on pouvait observer à la fin de la période d'étude une diminution importante des deux énantiomères de VEN, 0-desmethy'lvenlafaxine (ODV), N-desmethylvenlafaxine (NDV) et N, 0-didesmethylvenlafaxine (NODV) dans le plasma. Cela suggère un manque de compliance chez ce patient, mais une induction métabolique par la carbamazepine ne peut pas être exclue entièrement. L'administration de la carbamazepine (moyen ± s.d. (range) ; 360 ± 89 (200-400) mg/jour)) pendant quatre semaines n'a pas eu comme résultat une modification significative des concentrations plasmatiques des énantiomères de VEN et de ses métabolites 0- et N-démethylés chez les autres patients. En conclusion, ces observations préliminaires suggèrent qu'une combinaison de VEN et de carbamazepine représente une stratégie intéressante par son efficacité, sa tolérance et l'absence de modifications pharmcocinétiques, mais ces résultats devraient être vérifiés dans une plus grande étude

Uptake-release by MSCs of a cationic platinum(II) complex active in vitro on human malignant cancer cell lines

In this study, the in vitro stability of cisplatin (CisPt) and cationic platinum(II)-complex (caPt(II)-complex) and their in vitro activity (antiproliferative and anti-angiogenic properties) were investigated against three aggressive human tumor cell lines. caPt(II)-complex shown a high stability until 9 days of treatment and displayed a significant and higher activity than CisPt against both NCI-H28 mesothelioma (19.37 \ub1 9.57 \u3bcM versus 34.66 \ub1 7.65 \u3bcM for CisPt) and U87 MG glioblastoma (19.85 \ub1 0.97 \u3bcM versus 54.14 \ub1 3.19 for CisPt). Mesenchymal Stromal Cells (AT-MSCs) showed a significant different sensitivity (IC50=71.9 \ub1 15.1 \u3bcM for caPt(II)-complex and 8.7 \ub1 4.5 \u3bcM for CisPt) to the antiproliferative activity of caPt(II)-complex and CisPt. The ability of MSCs to uptake both the drugs in a similar amount of 2.49 pM /cell, suggested a possible development of new therapies based on cell mediated drug delivery

Gemcitabine-releasing mesenchymal stromal cells inhibit in vitro proliferation of human pancreatic carcinoma cells

BACKGROUND AIMS: Pancreatic cancer (pCa) is a tumor characterized by a fibrotic state and associated with a poor prognosis. The observation that mesenchymal stromal cells (MSCs) migrate toward inflammatory micro-environments and engraft into tumor stroma after systemic administration suggested new therapeutic approaches with the use of engineered MSCs to deliver and produce anti-cancer molecules directly within the tumor. Previously, we demonstrated that without any genetic modifications, MSCs are able to deliver anti-cancer drugs. MSCs loaded with paclitaxel by exposure to high concentrations release the drug both in vitro and in vivo, inhibiting tumor proliferation. On the basis of these observations, we evaluated the ability of MSCs (from bone marrow and pancreas) to uptake and release gemcitabine (GCB), a drug widely used in pCa treatment. METHODS: MSCs were primed by 24-h exposure to 2000 ng/mL of GCB. The anti-tumor potential of primed MSCs was then investigated by in vitro anti-proliferation assays with the use of CFPAC-1, a pancreatic tumor cell line sensitive to GCB. The uptake/release ability was confirmed by means of high-performance liquid chromatography analysis. A cell-cycle study and secretome evaluation were also conducted to better understand the characteristics of primed MSCs. RESULTS: GCB-releasing MSCs inhibit the growth of a human pCa cell line in vitro. CONCLUSIONS: The use of MSCs as a "trojan horse" can open the way to a new pCa therapeutic approach; GCB-loaded MSCs that integrate into the tumor mass could deliver much higher concentrations of the drug in situ than can be achieved by intravenous injection

Circulating T regulatory cells migration and phenotype in glioblastoma patients: An in vitro study

Glioblastoma multiforme (GBM) is the most aggressive primary human brain tumor. The relatively high amount of T regulatory lymphocytes present in the tumor, contributes to the establishment of an immunosuppressive microenvironment. Samples of peripheral blood were collected from GBM patients and healthy controls and a purified population of Treg (CD4+/ CD25bright) was isolated using flow cytometric cell sorting. Treg migrating capacities toward human glioma cell line conditioned medium were evaluated through an in vitro migration test. Our data show that supernatants collected from GBM cell lines were more attractant to Treg when compared to complete standard medium. The addition of an anti-CCL2 antibody to conditioned medium decreased conditioned medium-depending Treg migration, suggesting that CCL2 (also known as Monocyte Chemoattractant Protein, MCP-1) is implicated in the process. The number of circulating CD4+/\u3bcL or Treg/\u3bcL was similar in GBM patients and controls. Specific Treg markers (FOXP3; CD127; Helios; GITR; CTLA4; CD95; CCR2, CCR4; CCR7) were screened in peripheral blood and no differences could be detected between the two populations. These data confirm that the tumor microenvironment is attractive to Treg, which tend to migrate toward the tumor region changing the immunological response. Though we provide evidence that CCL2 is implicated in Treg migration, other factors are needed as well to provide such effect. \ua9 2013 Springer Science+Business Media New York

Neutralization of schwann cell-secreted VEGF is protective to in vitro and in vivo experimental diabetic neuropathy

The pathogenetic role of vascular endothelial growth factor (VEGF) in long-term retinal and kidney complications of diabetes has been demonstrated. Conversely, little is known in diabetic neuropathy. We examined the modulation of VEGF pathway at mRNA and protein level on dorsal root ganglion (DRG) neurons and Schwann cells (SC) induced by hyperglycaemia. Moreover, we studied the effects of VEGF neutralization on hyperglycemic DRG neurons and streptozotocin-induced diabetic neuropathy. Our findings demonstrated that DRG neurons were not affected by the direct exposition to hyperglycaemia, whereas showed an impairment of neurite outgrowth ability when exposed to the medium of SC cultured in hyperglycaemia. This was mediated by an altered regulation of VEGF and FLT-1 receptors. Hyperglycaemia increased VEGF and FLT-1 mRNA without changing their intracellular protein levels in DRG neurons, decreased intracellular and secreted protein levels without changing mRNA level in SC, while reduced the expression of the soluble receptor sFLT-1 both in DRG neurons and SC. Bevacizumab, a molecule that inhibits VEGF activity preventing the interaction with its receptors, restored neurite outgrowth and normalized FLT-1 mRNA and protein levels in co-cultures. In diabetic rats, it both prevented and restored nerve conduction velocity and nociceptive thresholds. We demonstrated that hyperglycaemia early affected neurite outgrowth through the impairment of SC-derived VEGF/FLT-1 signaling and that the neutralization of SC-secreted VEGF was protective both in vitro and in vivo models of diabetic neuropathy

Sensitivity of mesenchymal stromal cells to a new imidazole-based cationic Pt(II) complex with high in vitro anticancer activity

OBJECTIVE: Platinum drugs endowed with a novel chemical structure could offer an alternative therapeutic strategy, allowing to enlarge the spectrum of activity and to overcome the many drawbacks of the well-known cisplatin (CisPt) and its derivatives. Our group synthesised a new caPt(II)-complex that showed a very effective cytotoxic effect on triple-negative breast cancer cells and on cell lines partially resistant to cisplatin. In this study, we compared the in vitro stability of CisPt and caPt(II)-complex and their in vitro activity against human tumour cell lines. The drug sensitivity of Mesenchymal Stromal Cells (MSCs) and their ability to uptake and release the drugs was also investigated. MATERIALS AND METHODS: AT-MSCs were isolated, characterized and expanded from human adipose tissue. Drug stability was studied following incubation at 37\ub0C in complete cell culture medium both in the absence and in the presence of a monolayer of MSCs. The effect of CisPt and caPt(II)-complex was tested against mesothelioma (NCI-H28), glioblastoma (U87MG), pancreatic adenocarcinoma (CFPAC-1) and AT-MSCs by using a MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium) anti-proliferative assay in 96 multiwell plates. The amount of drugs incorporated and released by AT-MSCs drugs was evaluated by inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: We found that caPt(II)-complex had a high stability until 9 days of treatment while CisPt lost its anticancer activity after only 24 hours of treatment. CisPt was significantly more active (IC50= 9.64 \ub1 5.10 \ub5M) than caPt(II)-complex (IC50= 21.25 \ub1 6.68 \ub5M) on CFPAC1 proliferation. On the contrary, caPt(II)-complex showed a significant higher activity than CisPt both against NCI-H28 mesothelioma (19.37 \ub1 9.57 \ub5M versus 34.66 \ub1 7.65 \ub5M for CisPt) and U87 MG (19.85 \ub1 0.97 \ub5M versus 54.14 \ub1 3.19 for CisPt). AT-MSCs showed a sensitivity to the cytotoxic effect of caPt(II)-complex (IC50=92.8 \ub1 28.9 \ub5M) and CisPt (IC50= 93.5 \ub1 47.6 \ub5M) that does not differ significantly but with a higher variability of response to CisPt expressed by different donors of AT-MSCs. To the antiproliferative activity of caPt(II)-complex and CisPt, AT-MSCs showed a significant different sensitivity (IC50= 71.9 \ub1 15.1 \ub5M for caPt(II)-complex and 8.7 \ub1 4.5 \ub5M for CisPt). AT-MSCs are able to uptake both the drugs in a similar amount of 2.49 pM /cell. DISCUSSION AND CONCLUSION: The high stability of caPt(II)-complex together with its significant anticancer activity against mesothelioma and glioblastoma makes this new platinum derivative a very interesting molecule able to improve cancer chemotherapy. The low sensitivity of AT- MSCs to the antiproliferative action exerted by caPt(II)-complex together with their ability to uptake and release the drug will be further investigated in order to optimize the drug loading procedure and verify the possibility to set up a system of cell mediated delivery of caPt(II) complex

Melanoma cells homing to the brain : an in vitro model

We developed an in vitro contact through-feet blood brain barrier (BBB) model built using type IV collagen, rat astrocytes, and human umbilical vein endothelial cells (HUVECs) cocultured through Transwell porous polycarbonate membrane. The contact between astrocytes and HUVECs was demonstrated by electron microscopy: astrocytes endfeet pass through the 8.0 \u3bcm pores inducing HUVECs to assume a cerebral phenotype. Using this model we evaluated transmigration of melanoma cells from two different patients (M1 and M2) selected among seven melanoma primary cultures. M2 cells showed a statistically significant higher capability to pass across the in vitro BBB model, compared to M1. Expression of adhesion molecules was evaluated by flow cytometry: a statistically significant increased expression of MCAM, \u3b1v\u3b23, and CD49b was detected in M1. PCR array data showed that M2 had a higher expression of several matrix metalloproteinase proteins (MMPs) compared to M1. Specifically, data suggest that MMP2 and MMP9 could be directly involved in BBB permeability and that brain invasion by melanoma cells could be related to the overexpression of many MMPs. Future studies will be necessary to deepen the mechanisms of central nervous system invasion

CXCR6, a Newly Defined Biomarker of Tissue-Specific Stem Cell Asymmetric Self-Renewal, Identifies More Aggressive Human Melanoma Cancer Stem Cells

Background: A fundamental problem in cancer research is identifying the cell type that is capable of sustaining neoplastic growth and its origin from normal tissue cells. Recent investigations of a variety of tumor types have shown that phenotypically identifiable and isolable subfractions of cells possess the tumor-forming ability. In the present paper, using two lineage-related human melanoma cell lines, primary melanoma line IGR39 and its metastatic derivative line IGR37, two main observations are reported. The first one is the first phenotypic evidence to support the origin of melanoma cancer stem cells (CSCs) from mutated tissue-specific stem cells; and the second one is the identification of a more aggressive subpopulation of CSCs in melanoma that are CXCR6+. Conclusions/Significance: The association of a more aggressive tumor phenotype with asymmetric self-renewal phenotype reveals a previously unrecognized aspect of tumor cell physiology. Namely, the retention of some tissue-specific stem cell attributes, like the ability to asymmetrically self-renew, impacts the natural history of human tumor development. Knowledge of this new aspect of tumor development and progression may provide new targets for cancer prevention and treatment