Cellular signaling: aspects for tumor diagnosis and therapy

Patterns of Cell Death Induced by Thiohydantoins in Human MCF-7 Breast Cancer Cells

BACKGROUND

Conventional therapies for breast cancer is still a challenge due to use of cytotoxic drugs not highly effective with major adverse effects. Thiohydantoins, are biologically active heterocyclic compounds reported by several biological activities, including anticarcinogenic properties, i.e., this work aimed to assess the use of thiohydantoin as a potential antitumor agent against MCF-7 breast cancer cells.

METHODS

MTT and neutral red assays were used to assess the possible cytotoxic activity of compounds against MCF-7 cells. Cell volume measurement and analysis were performed by flow cytometry, fluorescence analysis was carried out to determine patterns of cell death induced by thiohydantoins.

RESULTS

The treatment with micromolar doses of thiohydantoins promoted a decrease in the viability of MCF-7 breast tumor cells. Also were observed the increase in ROS and NO production, reduction in cell volume, loss of membrane integrity, mitochondrial depolarization, and increased fluorescence for annexin V and caspase-3. These findings indicate cell death by apoptosis and increased formation of autophagic vacuoles and stopping the cell cycle in the G1/ G0 phase.

CONCLUSIONS

Our results indicate that thiohydantoins are cytotoxic to breast tumor cells, and this effect is linked to the increase in ROS production. This phenomenon changes tumorigenic pathways, that lead to a halt of the cell cycle in G1/G0, an important checkpoint for DNA errors, which may have altered the process by which cells produce energy, causing a decrease in mitochondrial viability and thus leading to the apoptotic process. Furthermore, the results indicate increased autophagy, a vital process linked to a decrease in lysosomal viability and considered as a cell death and tumor suppression mechanism.

Effects of Baneh (Pistacia atlantica) Gum on Human Breast Cancer Cell Line (MCF-7) and Its Interaction with Anticancer Drug Doxorubicin

Pistacia atlantica is one of the species of Anacardiaceae that grows in the wild in different regions of Iran. Traditionally, anacardiaceae family has antibacterial, fungicidal, and cytotoxic properties. Therefore, the present study was designed to investigate the possible cytotoxic and anti-proliferative properties of Baneh gum. Cytotoxicity of the plant gum was determined using MTT assay on MCF-7 human breast cancer cells. The cellular makers of apoptosis (caspase3 and P53) and cell proliferation (Cyclin-D1) were evaluated by western blotting. Doxorubicin was used as anticancer control drug in combination treatment. The result showed that Baneh gum (100 µg/mL) significantly induced cell damage, activated caspase3, and increased P53 protein level. In addition, Cyclin-D1 was significantly decreased in gum-incubated cells. Furthermore, combination treatment of cells with Baneh gum (25 µg/mL) and doxorubicin (200 nM) produced a significant cytotoxic effect as compared to each drug alone. In conclusion, Baneh gum (100 µg/mL) has a potential pro-apoptotic/anti-proliferative property against human breast cancer cells and its combination with doxorubicin in low doses may induce cell death effectively and be a potent modality to treat this type of cancer.

Synthetic lethality: emerging targets and opportunities in melanoma

Great progress has been made in the treatment of melanoma through use of targeted therapies and immunotherapy. One approach that has not been fully explored is synthetic lethality, which exploits somatically acquired changes, usually driver mutations, to specifically kill tumour cells. We outline the various approaches that may be applied to identify synthetic lethal interactions and define how these interactions may drive drug discovery efforts.

Cytotoxic Effect of Thymus caramanicus Jalas on Human Oral Epidermoid Carcinoma KB Cells

Abstract Identifying new chemotherapeutic agents with fewer side effects is a major concern for scientists today. Thymus caramanicus Jalas (Lamiaceae family) is one of the species of Thymus that grows wild in different regions of Iran. Traditionally, leaves of this plant are used in the treatment of diabetes, arthritis and cancer. Here was investigated the cytotoxic property of Thymus caramanicus essential oil and extract in human oral epidermoid carcinoma KB cells. Cell viability was measured by MTT and neutral red assays. The cells were exposed to different concentrations of essential oil (0.05-1 µL/mL) and extract (25-150 µg/mL) for 24 h. Doxorubicin was used as anticancer control drug. The data showed that the essential oil (IC50=0.44 µL/mL) and extract (IC50=105 µg/mL) induce potent cytotoxic property. Surprisingly, cytotoxic effects of essential oil and extract of this plant on KB cancer cells were greater than those on normal gingival HGF1-PI1 cell line. In addition, Thymus caramanicus could potentiate the effect of doxorubicin in sub-effective concentrations. The results of the present study indicate that essential oils and extracts of Thymus caramanicus have potential anti-proliferative property on KB cells and can be used as pharmaceutical case study for oral cancer treatments.

Inhibitory and Cytotoxic Activities of Chrysin on Human Breast Adenocarcinoma Cells by Induction of Apoptosis

Objectives:

Chrysin, an active natural bioflavonoid found in honey and many plant extracts, was first known for its antioxidant and anti-inflammatory effects. The fact that antioxidants have several inhibitory effects against different diseases, such as cancer, led to search for food rich in antioxidants. In this study, we investigated the antiproliferative and apoptotic effects of chrysin on the cultured human breast cancer cells (MCF-7).

Materials and Methods:

Cells were cultured in Roswell Park Memorial Institute medium and treated with different chrysin concentrations for three consecutive days. Cell viability was quantitated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The percentage of apoptotic cells was determined by flow cytometry using Annexin V-fluorescein isothiocyanate.

Results:

The MTT assay showed that chrysin had an antiproliferative effect on MCF-7 cells in a dose- and time-dependent manner. The 50% cell growth inhibition values for chrysin against MCF-7 cells were 19.5 and 9.2 μM after 48 and 72 h, respectively. Chrysin induced apoptosis in MCF-7 cells as determined by flow cytometry. Chrysin inhibits the growth of the breast cancer cells by inducing cancer cell apoptosis which may, in part, explain its anticancer activity.

Conclusion:

This study shows that chrysin could also be considered as a promising chemotherapeutic agent and anticancer activity in treatment of the breast cancer cells in future.

SUMMARY

Chrysin had an antiproliferative effect on human breast cancer cells (MCF-7) cells in a dose- and time-dependent manner

Chrysin induced apoptosis in MCF-7 cells, as determined by flow cytometry

Chrysin inhibits the growth of the breast cancer cells by inducing cancer cell apoptosis

Chrysin may have anticancer activity.

Abbreviations used: Human breast cancer cells (MCF-7), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), phosphate-buffered saline (PBS), normal fibroblast mouse (L929).

Label-free monitoring of whole cell vitality

The Intelligent Mobile Lab (IMOLA) delivers metabolic and morphological parameters of living cells in a label-free and real time way. It represents a key technology for the development of new cell-based assays. Electrochemical microsensors are used to measure the extracellular acidification (pH), cellular respiration (pO2), changes in cell number and morphology (electric impedance) in a controlled environment. These parameters are closely linked to the intracellular signaling network of the living cells. They are thus likely to respond sensitively to changes in cellular vitality. A wide spectrum of cell types can be tested with the system, including adherent and suspended cells, continuous cell lines, primary cells or tissue samples. The platform is described in detail and applications in the field's oncology, toxicology and environmental monitoring are shown.

Proapoptotic and Antiproliferative Effects of Thymus caramanicus on Human Breast Cancer Cell Line (MCF-7) and Its Interaction with Anticancer Drug Vincristine

Thymus caramanicus Jalas is one of the species of thymus that grows in the wild in different regions of Iran. Traditionally, leaves of this plant are used in the treatment of diabetes, arthritis, and cancerous situation. Therefore, the present study was designed to investigate the selective cytotoxic and antiproliferative properties of Thymus caramanicus extract (TCE). MCF-7 human breast cancer cells were used in this study. Cytotoxicity of the extract was determined using MTT and neutral red assays. Biochemical markers of apoptosis (caspase 3, Bax, and Bcl-2) and cell proliferation (cyclin D1) were evaluated by immunoblotting. Vincristine was used as anticancer control drug in extract combination therapy. The data showed that incubation of cells with TCE (200 and 250 μg/mL) significantly increased cell damage, activated caspase 3 and Bax/Bcl2 ratio. In addition, cyclin D1 was significantly decreased in TCE-treated cells. Furthermore, concomitant treatment of cells with extract and anticancer drug produced a significant cytotoxic effect as compared to extract or drugs alone. In conclusion, thymus extract has a potential proapoptotic/antiproliferative property against human breast cancer cells and its combination with chemotherapeutic agent vincristine may induce cell death effectively and be a potent modality to treat this type of cancer.

Anti-proliferative and pro-apoptotic effect of carvacrol on human hepatocellular carcinoma cell line HepG-2

Carvacrol is one of the members of monoterpene phenol and is present in the volatile oils of Thymus vulgaris, Carum copticum, origanum and oregano. It is a safe food additive commonly used in our daily life, and few studies have indicated that carvacrol has anti-hepatocarcinogenic activities. The rationale of the study was to examine whether carvacrol affects apoptosis of human hepatoma HepG2 cells. In this study, we showed that carvacrol inhibited HepG2 cell growth by inducing apoptosis as evidenced by Hoechst 33258 stain and Flow cytometric (FCM) analysis. Incubation of HepG2 cells with carvacrol for 24 h induced apoptosis by the activation of caspase-3, cleavage of PARP and decreased Bcl-2 gene expression. These results demonstrated that a significant fraction of carvacrol treated cells died by an apoptotic pathway in HepG2 cells. Moreover, carvacrol selectively altered the phosphorylation state of members of the MAPK superfamily, decreasing phosphorylation of ERK1/2 significantly in a dose-dependent manner, and activated phosphorylation of p38 but not affecting JNK MAPK phosphorylation. These results suggest that carvacrol may induce apoptosis by direct activation of the mitochondrial pathway, and the mitogen-activated protein kinase pathway may play an important role in the antitumor effect of carvacrol. These results have identified, for the first time, the biological activity of carvacrol in HepG2 cells and should lead to further development of carvacrol for liver disease therapy.

From cell signaling to cancer therapy

Cancer has been seriously threatening the health and life of humans for a long period. Despite the intensive effort put into revealing the underlying mechanisms of cancer, the detailled machinery of carcinogenesis is still far from fully understood. Numerous studies have illustrated that cell signaling is extensively involved in tumor initiation, promotion and progression. Therefore, targeting the key molecules in the oncogenic signaling pathway might be one of the most promising ways to conquer cancer. Some targeted drugs, such as imatinib mesylate (Gleevec), herceptin, gefitinib (Iressa), sorafenib (Nexavar) and sunitinib (Sutent), which evolve from monotarget drug into multitarget ones, have been developed with encouraging effects.