5-FU and the dietary flavonoid carvacrol: a synergistic combination that induces apoptosis in MCF-7 breast cancer cells.

Along with the benefits of chemotherapy in the treatment of breast cancer, the side effects of these drugs along with drug resistance make their use complicated. One of the solutions to overcome this problem is the use of herbal products and combination therapy. In this research, we try to investigate the effects of carvacrol, a monoterpene flavonoid, in combination with the chemotherapy drug 5-FU. Combination index method was used for the drug-drug interactions analysis based on the Chou and Talalay method and the data from MTT assays. Apoptosis was assessed by the ELISA cell death method. P-glycoprotein expression was evaluated at the gene level by Real-time PCR. Here, we described the first experimental evidence for the existence of synergism between carvacrol and 5-FU in the in vitro model of breast cancer. MTT assay results showed combination treatment of the cells with carvacrol and 5-FU decreased 5-FU concentrations significantly. Incubation of the cells with carvacrol neutralized P-glycoprotein overexpression in qPCR assay (P ≤ 0.05). Compared with adding verapamil (a P-glycoprotein inhibitor) to 5-FU, the combination of carvacrol and 5-FU caused a further increase in the percentage of apoptotic cells when the cells were treated with both agents. Our results suggest that carvacrol can downregulate P-gp expression and combination therapy with carvacrol and 5-FU is considered a novel approach to improve the efficacy of chemotherapeutics in cancer patients with high P-glycoprotein expression.

Interaction of viral oncogenic proteins with the Wnt signaling pathway.

It is estimated that up to 20% of all types of human cancers worldwide are attributed to viruses. The genome of oncogenic viruses carries genes that have protein products that act as oncoproteins in cell proliferation and transformation. The modulation of cell cycle control mechanisms, cellular regulatory and signaling pathways by oncogenic viruses, plays an important role in viral carcinogenesis. Different signaling pathways play a part in the carcinogenesis that occurs in a cell. Among these pathways, the Wnt signaling pathway plays a predominant role in carcinogenesis and is known as a central cellular pathway in the development of tumors. There are three Wnt signaling pathways that are well identified, including the canonical or Wnt/ß-catenin dependent pathway, the noncanonical or ß-catenin-independent planar cell polarity (PCP) pathway, and the noncanonical Wnt/Ca2+ pathway. Most of the oncogenic viruses modulate the canonical Wnt signaling pathway. This review discusses the interaction between proteins of several human oncogenic viruses with the Wnt signaling pathway.

Cytotoxic Effects of Coated Gold Nanoparticles on PC12 Cancer Cell.

BACKGROUND: The use of gold nanoparticles in medicine and especially in cancer treatment has been of interest to researchers. The effectiveness of this nanoparticle on cells significantly depends on the amount of its entry into the cells. This study was performed to compare the rate and mechanism of effect of gold nanoparticles coated with different amino acid on PC12 cancer cell line. MATERIALS AND METHODS: The PC12 cells line were exposed to various concentrations of amino acid coated and uncoated gold nanoparticles (0.5, 2.5 and 5 µM). Cell death rate was determined according to level of Lactate dehydrogenase (LDH) release from cells and MTT assay. In addition cell morphology and the amount of Cellular Reactive oxygen species (ROS) were studied. RESULTS: The uncoated gold nanoparticles have shown minor effects on cellular life. Gold nanoparticles coated by tryptophan at high concentrations (2.5, 5 and 25µM) increase in cancer cells metabolic activity. Gold nanoparticles coated by Aspartate also produce the largest amount of LDH and ROS in cancer cells and therefore caused of highest rate of apoptosis. CONCLUSION: The results showed that the nanoparticles coated with amino acids are affected on cellular metabolism and apoptosis more than uncoated nanoparticles. Also the smallest coated nanoparticles (coated by aspartate) have the most influence and by increasing the size, this effect was reduced.