Growth inhibition, G1-arrest, and apoptosis in MCF-7 human breast cancer cells by novel highly lipophilic 5-fluorouracil derivatives

Abstract

In this study we evaluate the antitumour activity, the cell cycle arrest and apoptotic properties of novel lipophilic benzene-fused seven-membered 5-fluorouracil (5-FU) analogs in comparison to 5-FU on MCF-7 human breast cancer cells. The lipophilicities of ESB-786B, ESB-252A and ESB-928A were predicted by using the CDR option of the PALLAS 2.0 program. Cytotoxic assays were evaluated in MCF-7 cells treated with the sulforhodamine B colorimetric method. Cell cycle perturbations were studied by flow cytometry. Apoptosis was determined by both DNA fragmentation and annexin V-FITC and propidium iodide staining. The novel derivatives were more lipophilic than 5-FU and induced a marked growth inhibition, in a dose-dependent manner. After treatment with IC(50) value (ranged from 2.5 to 22 microM) for each compound, light microscopy observation showed modifications in the morphology of MCF-7 cells. In addition, the 5-FU analogs arrest cells in the G(0)/G(1) phase of the cell cycle whereas 5-FU induced arrest in S-phase. Moreover, induction of apoptosis was demonstrated by the annexin-V-based assay and confirmed using DNA fragmentation analysis on MCF-7 cells, a cell line in which the induction of DNA laddering is very difficult. The novel benzannelated seven-membered 5-FU analogs can be considered as specific apoptotic inducers. These experimental findings provide support for the use of these novel compounds as new weapons in the fight against breast cancer.

3,3′,5-Triiodo-l-thyronine inhibits ductal pancreatic adenocarcinoma proliferation improving the cytotoxic effect of chemotherapy

“…The T 3 -dependent cell growth inhibition was also confirmed by FACS analysis indicating a substantial reduction of cell population entering in S phase and evidencing an increase in the percentage of resting cells in G 0 /G 1 phase of the cell cycle, as already reported for Neuro-2a cells, (Lebel et al 1994, Garcia-Silva et al 2002 rat chondrocyte primary culture (Ballock et al 2000), murine embryonic carcinoma P19 cells (Nygard et al 2003), and rat oligodendrocyte precursor cells (Tokumoto et al 1999). It is widely recognized that anti-proliferative agents can induce cell cycle perturbations associated with growth arrest (Otto et al 1996, Marchal et al 2004. In this context our results indicated that T 3 not only exerts an anti-proliferative action on our cells, but is also able to alter the cell cycle distribution.…”

Apoptosis as a Therapeutic Target in Cancer and Cancer Stem Cells: Novel Strategies and Futures Perspectives

“…The following two consequences can be stated: (a) in contrast to 5-FU, the six-membered compounds 11-13 provoked a G0/G1-phase cell cycle arrest when the MCF-7 cells were treated during 48 h with the IC50 of the compounds, mainly at the expense of the S-phase populations. The fact that at similar doses the novel derivatives exhibit different sequences of cell cycle perturbations in comparison with 5-FU indicates that these compounds act by different pathways [12]. In the case of 12 it is worth pointing out that, moreover, there is an increase in the G2/M-phase of the cancerous cells; and (b) the apoptotic indices of the target compounds are very important, especially for 13 (58.29% for 11, 63.05% for 12, and 76.22% for 13).…”

“…Cell cycle a Apoptosis b a Determined by flow cytometry [12]. b Apoptosis was determined using an Annexin V-based assay [12].…”

“…b Apoptosis was determined using an Annexin V-based assay [12]. The data indicate the percentage of cells undergoing apoptosis in each sample.…”

“…Therefore, apoptosis plays an important role in the treatment of cancer as it is a popular target of many treatment strategies. 5-fluorouracil (5-FU), an antimetabolite analogue of uracil employed primarily in the treatment of a variety of solid malignant tumours, leads to a wide range of biological effects which can act as triggers for apoptotic cell death [12,13]. However, resistance to the drug remains a major clinical problem.…”