Search results for "POINT"

Physiological concentrations of phytosterols enhance the apoptotic effects of 5-fluorouracil in colon cancer cells

2018

Abstract Combining natural products as co-adjuvants in 5-fluorouracil (5-FU) chemotherapy might enhance the effectiveness of 5-FU by avoiding a high dosage and/or reducing treatment times. We explored the anticancer efficacy of the phytosterols (PS) at concentrations achievable in the human colon, as well as their potential as sensitizing agents of human colon cancer cells (Caco-2 and HT-29) to 5-FU treatment. Cells proliferation, combination index, cell cycle, apoptosis, caspases activation, ROS production, and ΔΨm were determined. Co-treatment (PS+5-FU) had an antiproliferative additive effect, and moreover, in general a significantly improved efficacy was observed on cell cycle arrest at…

PTP1B phosphatase as a novel target of oleuropein activity in MCF-7 breast cancer model.

2019

Phosphatase PTP1B has become a therapeutic target for the treatment of type 2-diabetes, whereas recent studies have revealed that PTP1B plays a pivotal role in pathophysiology and development of breast cancer. Oleuropein is a natural, phenolic compound with anticancer activity. The aim of this study was to address the question whether PTP1B constitutes a target for oleuropein in breast cancer MCF-7 cells. The cellular MCF-7 breast cancer model was used in the study. The experiments were performed using cellular viability tests, Elisa assays, immunoprecipitation, flow cytometry analyses and computer modelling. Herein, we evidenced that the reduced activity of phosphatase PTP1B after treatmen…

[1,2]Oxazolo[5,4-e]isoindoles as promising tubulin polymerization inhibitors

2016

Abstract A series of [1,2]Oxazolo [5,4- e ]isoindoles has been synthesized through a versatile and high yielding sequence. All the new structures showed in the 1 HNMR spectra, the typical signal in the 8.34–8.47 ppm attributable to the H-3 of the [1,2]oxazole moiety. Among all derivatives, methoxy benzyl substituents at positions 3 and 4 or/and 5 were very effective in reducing the growth of different tumor cell lines, including diffuse malignant peritoneal mesothelioma (DMPM), an uncommon and rapidly malignancy poorly responsive to available therapeutic options. The most active compound 6j was found to impair tubulin polymerization, cause cell cycle arrest at G2/M phase and induce apoptosi…

New insights into the mechanism of action of pyrazolo[1,2-a]benzo[1,2,3,4]tetrazin-3-one derivatives endowed with anticancer potential

2018

Due to the scarce biological profile, the pyrazolo[1,2-a]benzo[1,2,3,4]tetrazine-3-one scaffold (PBT) has been recently explored as promising core for potential anticancer candidates. Several suitably decorated derivatives (PBTs) exhibited antiproliferative activity in the low-micromolar range associated with apoptosis induction and cell cycle arrest on S phase. Herein, we selected the most active derivatives and submitted them to further biological explorations to deepen the mechanism of action. At first, a DNA targeting is approached by means of flow Linear Dichroism experiments so as to evaluate how small planar molecules might interact with DNA, including the interference with the catal…

Carob leaf polyphenols trigger intrinsic apoptotic pathway and induce cell cycle arrest in colon cancer cells

2017

IF 3.973; International audience; Chemoprevention of Colorectal cancer (CRC) is the major concern for improving public health. We investigated the protective effects of carob, Ceratonia siliqua L, leaf polyphenols (CLP) against CRC. Phenolic content analysis showed that CLP is enriched with gallic acid and m-coumaric acid. We observed that CLP exerted a dose dependent cytotoxic effect through the induction of apoptosis on CRC cell lines, with an IC50 around 20 mu g/mL CLP induced intrinsic apoptotic pathway through the caspase-9 activation and PARP cleavage in HCT-116 and CT-26 cells. Moreover, CLP induced cell cycle arrest in the G1 phase through p53 activation. Gallic acid and m-coumaric …

Design, synthesis, and biological evaluation of a new class of benzo[b]furan derivatives as antiproliferative agents, with in silico predicted antitu…

2018

A new series of 3-benzoylamino-5-(1H-imidazol-4-yl)methylaminobenzo[b]furans were synthesized and screened as antitumor agents. As a general trend, tested compounds showed concentration-dependent antiproliferative activity against HeLa and MCF-7 cancer cell lines, exhibiting GI50 values in the low micromolar range. In most cases, insertion of a methyl substituent on the imidazole moiety improved the antiproliferative activity. Therefore, methyl-imidazolyl-benzo[b]furans compounds were tested in cell cycle perturbation experiments, producing cell cycle arrest with proapoptotic effects. Their core similarity to known colchicine binding site binders led us to further study the structure featur…

Polyphenols from Pennisetum glaucum grains induce MAP kinase phosphorylation and cell cycle arrest in human osteosarcoma cells

2019

Abstract Osteosarcoma is the most common bone tumor with a high prevalence among children and adolescents. Polyphenols are widely investigated for their chemopreventive and chemotherapeutic proprieties. In the present study, we explored the pro-apoptotic effects of pearl millet, Pennisetum glaucum, phenolic compounds (PGPC) on osteosarcoma U-2OS cells. Our results show that PGPC induced U-2OS cells death, in a dose dependent manner, with an IC50 of 80 μg/mL. Annexin-V and 7-AAD staining show that PGPC induced cell death mainly through caspase-dependent apoptosis as shown by a decrease in cell death when co-treated with pan-caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketon…

2020

Immune checkpoint inhibitors (ICPi) have shown their superiority over conventional therapies to treat some cancers. ICPi are effective against immunogenic tumors. However, patients with tumors poorly infiltrated with immune cells do not respond to ICPi. Combining ICPi with other anticancer therapies such as chemotherapy, radiation, or vaccines, which can stimulate the immune system and recruit antitumor T cells into the tumor bed, may be a relevant strategy to increase the proportion of responding patients. Such an approach still raises the following questions: What are the immunological features modulated by immunogenic therapies that can be critical to ensure not only immediate but also l…

2018

Background: Chemotherapy is currently evaluated in order to enhance the efficacy of immune checkpoint blockade (ICB) therapy in colorectal cancer. However, the mechanisms by which these drugs could...

The IgG1 B-cell receptor provides survival and proliferative signals analogue to the Igα but not the Igβ co-receptor.

2016

The function of the IgM B-cell receptor (BCR) is dependent on intact signaling of the co-receptors Igα and Igβ, both of which contain a cytoplasmic tail bearing an immunoreceptor tyrosine-based activation motif. We have previously demonstrated that the cytoplasmic tail of the IgG1 BCR can partially compensate for the loss of the signaling moiety of Igα. Here, we show that unlike Igα, Igβ signaling is indispensable for the development and function of IgG1-expressing B cells. Deletion of the cytoplasmic signaling tail of Igβ compromised the survival and proliferation not only of IgM(+) B cells but also of IgG1-expressing B cells. In the absence of the signaling tail of Igβ, the transcription …