Targeting the monocarboxylate transporter MCT2 and lactate dehydrogenase A LDHA in cancer cells with FX-11 and AR-C155858 inhibitors.

OBJECTIVE: In 1930, Otto Warburg reported that "aerobic glycolysis" is the intrinsic property of all tumor cells' fermentation of glucose to L-Lactate by lactate dehydrogenase A (LDHA) activity. This only produces per mole of glucose two moles of adenosine triphosphate (ATP), compared with 32 moles of ATP in a normal cell. Thus, tumor cells have to uptake 30 folds more glucose, the resulting accumulated lactate are then transported by a monocarboxylate transporter (MCT) with the participation of a CD147 molecule. Inhibition of MCT1 by RNA interference (RNAi) disrupted the unique metabolism of the tumor and caused tumor cell death. However, the effectiveness of the strategies depends on the targeted delivery of the therapeutics. MATERIALS AND METHODS: In this study, a synergistic approach was used to target LDHA and MCT1 with small molecule inhibitors FX11 and AR-C155858, respectively. Cell cytotoxicity assays (AlamarBlue assay), and Mitochondria Membrane Potential (JC-1) dye assays were performed on human breast cancer cells MCF-7 and colorectal cancer cells HCT116. To achieve this aim, the following objectives were proposed: the effect of metabolic inhibitors on tumor glycolytic metabolite environment, and the efficacy of metabolite inhibitors on human breast and colorectal cancer cells in vitro. Then, gene expression analysis was performed using Qiagen RT2 Profiler PCR array for apoptosis. All these assays were performed on human breast cancer cells MCF-7 and colorectal cancer cells HCT116. Normal human fibroblasts were used as control cells under normal and hypoxic culture conditions. RESULTS: In this study, the use of FX-11 inhibitors under normoxia or hypoxia in two or more cancer and normal cell lines has a direct effect on LDHA, whereby it inhibits its production, and this reduces the growth and cell proliferation of tumors. One of the more significant findings to emerge from this study is that using AR-C155858 inhibitor alone has increased the cell proliferation and showed no significant changes compared with the control. The other major finding was that combination of the two inhibitors, FX-11 and AR-C155858, under normoxia or hypoxia in two different cell lines MCF-7 and HCT-116 measured a decrease in the cells proliferative and red/green ratio. CONCLUSIONS: We successfully demonstrated that a combination of MCT1 inhibitor and LDHA inhibitor led to better outcomes. Indeed, this makes LDHA an ideal metabolic therapeutic target.

Vorinostat induces G2/M cell cycle arrest in breast cancer cells via upregulation of PTEN.

OBJECTIVE: Breast cancer (BC) is the most common type of cancer in females worldwide. Various approaches were proposed to treat the disease, with no sole agent proved efficient. Thus, understanding the molecular mechanisms of different drugs became mandatory. The present study aimed at evaluating the role of erlotinib (ERL) and vorinostat (SAHA) in inducing apoptosis in breast cancer cells. The role of these drugs was assessed also on the expression profile of some cancer-related genes; PTEN, P21, TGF, and CDH1. MATERIALS AND METHODS: In the present study, breast cancer cells (MCF-7) and MDA-MB-231 along with human amniotic cells (WISH) were treated with two concentrations (50, and 100 µM) of erlotinib (ERL) and vorinostat (as known as SAHA) for 24 h. Cells were harvested for downstream analysis. DNA content and apoptosis were analyzed by flow cytometer, and qPCR was performed to assess the expression of different cancer-related genes. RESULTS: The results indicated that ERL and SAHA arrested both breast cancer cells at the G2/M phase after 24 h compared to normal cells and control. For apoptosis, BC cells showed an elevated level of total apoptosis (early and late) increasing the concentrations of the two applied drugs, with the most effective concentration of ERL at 100 µM in the 24-h treatment. In the control cells, SAHA was proved to be the most effective drug at a concentration of 100 µM with a percentage of apoptosis ranging from 1.7-12% in the 24-h treatment. Necrosis also was dose-dependent in the two breast cancer cell lines used. We further evaluated the expression profiles of PTEN, P21, TGF-ß, and CDH1. In MCF-7, data indicated that for TGF-ß, PTEN, and P21, the most effective treatment was SAHA at a concentration of 100 µM, while for CDH1, the most effective concentration was ERL at 100 µM. A similar profile was observed in MDA-MB-232, where for TGF-ß, PTEN, and P21, the most effective treatment was SAHA at a concentration of 100 µM, while for CDH1, the most effective concentration was SAHA at 50 µM. CONCLUSIONS: Our results shed some light on the role of ERL and SAHA in regulating the expression of cancer-related genes, though these data need further investigation.

The inhibitory and anticancer properties of Annona squamosa L. seed extracts.

Although Annona squamosa Linn. (Annonaceae) has been used in traditional medicine and is known to have several pharmacological properties, its impact on EGFR kinase has not been fully investigated. An assay (biochemical) was used to govern the potential of different A. squamosa seed extracts to scavenge free radicals in petroleum ether, acetone, ethanol, and methanol. We also tested A. squamosa leaf extracts for their ability to inhibit the growth of HEK 293, MCF7, and HepG2 cell lines. The PSE, ASE, ESE, and MSE all contained anti-cancer substances like anethole, cyclopentane, 1,1,3-trimethyl, and phosphonate oxide tributyl, according to phytochemical analysis. ESE extracts from A. squamosa seeds have been selected based on free radical generation probabilities, cytotoxicity studies, and phytochemical analysis. Subsequent insilico studies have been conducted, and the results have shown that interactions between compounds present in ESE extracts and the EGFR kinase are what give these compounds their inhibitory effects. Preliminary phytochemical and pharmacological activities were studied and reported. A. squamosa ESE extracts inhibited the growth of MCF7 cells, and a pharmacokinetic study showed that the compounds anethole, cyclopentane, 1,1,3-trimethyl, and phosphonium oxide tributyl had few undesirable side effects. These substances can be used to both prevent and treat cancer diseases.