Search results for "Say"

Comparative analysis of the effects of a sphingosine kinase inhibitor to temozolomide and radiation treatment on glioblastoma cell lines.

2017

ABSTRACT Glioblastoma multiforme (GBM) exhibits high resistance to the standard treatment of temozolomide (TMZ) combined with radiotherapy, due to its remarkable cell heterogeneity. Accordingly, there is a need to target alternative molecules enhancing specific GBM autocrine or paracrine mechanisms and amplifying the effect of standard treatment. Sphingosine 1-phosphate (S1P) is such a lipid target molecule with an important role in cell invasion and proliferation. Sphingosine kinase inhibitors (SKI) prevent S1P formation and induce increased production of reactive oxygen species (ROS), which may potentiate radiation cytotoxicity. We analyzed the effect of SKI singular versus combined treat…

Tumor-Associated Fibroblasts Promote HER2-Targeted Therapy Resistance through FGFR2 Activation

2020

AbstractPurpose:Despite the therapeutic success of existing HER2-targeted therapies, tumors invariably relapse. This study aimed at identifying new mechanisms responsible for HER2-targeted therapy resistance.Experimental Design:We have used a platform of HER2-targeted therapy–resistant cell lines and primary cultures of healthy and tumor-associated fibroblasts (TAF) to identify new potential targets related to tumor escape from anti-HER2 therapies.Results:We have shown that TAFs promote resistance to HER2-targeted therapies. TAFs produce and secrete high levels of FGF5, which induces FGFR2 activation in the surrounding breast cancer cells. FGFR2 transactivates HER2 via c-Src, leading to res…

Targeting COPZ1 non-oncogene addiction counteracts the viability of thyroid tumor cells

2017

Abstract Thyroid carcinoma is generally associated with good prognosis, but no effective treatments are currently available for aggressive forms not cured by standard therapy. To find novel therapeutic targets for this tumor type, we had previously performed a siRNA-based functional screening to identify genes essential for sustaining the oncogenic phenotype of thyroid tumor cells, but not required to the same extent for the viability of normal cells (non-oncogene addiction paradigm). Among those, we found the coatomer protein complex ζ1 (COPZ1) gene, which is involved in intracellular traffic, autophagy and lipid homeostasis. In this paper, we investigated the mechanisms through which COPZ…

Chronic Sulforaphane Application Does Not Induce Resistance in Renal Cell Carcinoma Cells.

2018

Background/aim Since the natural compound sulforaphane (SFN) has been shown to stop tumor growth, renal cell carcinoma (RCC) patients often use this drug in addition to their prescribed oncotherapy. The aim of this study was to examine whether resistance to SFN may develop after long-term application. Materials and methods Several RCC cell lines were incubated with SFN for short periods of time (24-72 h) or long periods of time (8 weeks) and cell growth, proliferation, and cell-cycle proteins were analyzed. Results Both short- and long-term application of SFN distinctly reduced RCC cell growth and proliferation. However, differences in the distribution of cells in each phase of the cell cyc…

Artesunate Inhibits Growth of Sunitinib-Resistant Renal Cell Carcinoma Cells through Cell Cycle Arrest and Induction of Ferroptosis

2020

Although innovative therapeutic concepts have led to better treatment of advanced renal cell carcinoma (RCC), efficacy is still limited due to the tumor developing resistance to applied drugs. Artesunate (ART) has demonstrated anti-tumor effects in different tumor entities. This study was designed to investigate the impact of ART (1&ndash

Inhibition of colon cancer growth by docosahexaenoic acid involves autocrine production of TNFα

2016

IF 7.932; International audience; The omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) has anti-inflammatory and anti-cancer properties. Among pro-inflammatory mediators, tumor necrosis factor a (TNF alpha) plays a paradoxical role in cancer biology with induction of cancer cell death or survival depending on the cellular context. The objective of the study was to evaluate the role of TNFa in DHA-mediated tumor growth inhibition and colon cancer cell death. The treatment of human colorectal cancer cells, HCT-116 and HCT-8 cells, with DHA triggered apoptosis in autocrine TNF alpha-dependent manner. We demonstrated that DHA-induced increased content of TNF alpha mRNA occurred thr…

Hypoxia-Inducible Factor-1α Activity as a Switch for Glioblastoma Responsiveness to Temozolomide

2018

Rationale: The activity of the transcription factor, hypoxia-inducible factor (HIF)-1?, is a common driver of a number of the pathways involved in the aggressiveness of glioblastomas (GBMs), and it has been suggested that the reduction in this activity observed, soon after the administration of temozolomide (TMZ), can be a biomarker of an early response in GBM models. As HIF-1? is a tightly regulated protein, studying the processes involved in its downregulation could shed new light on the mechanisms underlying GBM sensitivity or resistance to TMZ. Methods: The effect of HIF-1? silencing on cell responsiveness to TMZ was assessed in four genetically different human GBM cell lines by evaluat…

2017

AbstractInterleukin-4 plays a critical role in the regulation of immune responses and has been detected at high levels in the tumour microenvironment of cancer patients, where concentrations correlate with the grade of malignancy. In prostate cancer, interleukin-4 has been associated with activation of the androgen receptor, increased proliferation and activation of survival pathways such as Akt and NF-κB. However, its role in therapy resistance has not yet been determined. Here we investigate the influence of interleukin-4 on primary epithelial cells from prostate cancer patients. Our data demonstrate an increase in the clonogenic potential of these cells when cultured in the presence of i…

Ligand-dependent Hedgehog pathway activation in Rhabdomyosarcoma : the oncogenic role of the ligands

2017

Altres ajuts: This work was supported by grants from Institut Català d'Oncologia (ICO), Instituto de Salud Carlos III (RTICC-RD12/0036/0016, /0020, /0035, /0057; and PI14/00647), Fundació A BOSCH, Fundació Amics Joan Petit, ajuts predoctorals del VHIR and RIS3CAT grants COMRDI15-1-0014 (ACCIÓ and FEDER). Altres ajuts: FEDER/COMRDI15-1-0014 Rhabdomyosarcoma (RMS) is the most common type of soft tissue sarcoma in children. The Hedgehog (HH) pathway is known to develop an oncogenic role in RMS. However, the molecular mechanism that drives activation of the pathway in RMS is not well understood. The expression of HH ligands was studied by qPCR, western blot and immunohistochemistry. Functional …

Red wine extract disrupts Th17 lymphocyte differentiation in a colorectal cancer context

2020

International audience; Scope: Scope: It is well established that immune response and inflammation promote tumoral progression. Immune cells communicate through direct contact or through cytokine secretion, and it is the pro-inflammatory status that will tip the balance toward tumor progression or anti-tumor immunity. It is demonstrated here that a red wine extract (RWE) can decrease inflammation through its action on the inflammasome complex. This study determines whether an RWE could impact other key actors of inflammation, including T helper 17 (Th17) immune cells in particular. Methods and results: Methods and results: Using an RWE containing 4.16 g of polyphenols/liter of wine, it is s…