Combined 18F-FDG PET/CT imaging and a gastric orthotopic xenograft model in nude mice are used to evaluate the efficacy of glycolysis-targeted therapy.

As discovered by Warburg 80 years ago most malignant cells rely more on glycolysis than normal cells. The high rate of glycolysis provides faster ATP production and greater lactic acid for tumor proliferation and invasion, thus indicating a potential target in anticancer therapy. Our previous studies demonstrated that 3-bromopyruvate (3-BrPA) and sodium citrate (SCT) inhibited tumor cell proliferation in vitro. However, the underlying mechanisms still warrant further investigation. In the present study, we employed the human SGC-7901 gastric cancer cell line, built an orthotopic xenograft model in nude mice, examined the treatment response by 18F-FDG PET/CT and investigated the mechanisms of 3-BrPA and SCT in vivo. Our results demonstrated that glycolysis and tumor growth were inhibited by intraperitoneal injection of 3-BrPA and SCT, which were imaged using an 18F-FDG PET/CT scanner. In addition, apoptosis induced by 3-BrPA and SCT was initiated by the upregulation of Bax and downregulation of Bcl-2, which promote cytochrome c release and subsequently activate caspase-9 and -3, and ultimately execute mitochondria-mediated apoptosis. Furthermore, apoptosis was also modulated by the generation of ROS and inhibition of survivin. Accordingly, 3-BrPA and SCT can inhibit glycolysis and induce gastric cancer apoptosis through the mitochondrial caspase-dependent pathway.

3-Bromopyruvate inhibits human gastric cancer tumor growth in nude mice via the inhibition of glycolysis.

[This retracts the article DOI: 10.3892/ol.2014.2779.].

3-bromopyruvate and sodium citrate target glycolysis, suppress survivin, and induce mitochondrial-mediated apoptosis in gastric cancer cells and inhibit gastric orthotopic transplantation tumor growth.

Glycolysis is the primary method utilized by cancer cells to produce the energy (adenosine triphosphate, ATP) required for cell proliferation. Therefore, inhibition of glycolysis may inhibit tumor growth. We previously found that both 3-bromopyruvate (3-BrPA) and sodium citrate (SCT) can inhibit glycolysis in vitro; however, the underlying inhibitory mechanisms remain unclear. In the present study, we used a human gastric cancer cell line (SGC-7901) and an orthotopic transplantation tumor model in nude mice to explore the specific mechanisms of 3-BrPA and SCT. We found that both 3-BrPA and SCT effectively suppressed cancer cell proliferation, arrested the cell cycle, induced apoptosis, and decreased the production of lactate and ATP. 3-BrPA significantly reduced the glycolytic enzyme hexokinase activity, while SCT selectively inhibited phosphofructokinase-1 activity. Furthermore, 3-BrPA and SCT upregulated the expression of pro-apoptotic proteins (Bax, cytochrome c, and cleaved caspase-3) and downregulated the expression of anti-apoptotic proteins (Bcl-2 and survivin). Finally, our animal model of gastric cancer indicated that intraperitoneal injection of 3-BrPA and SCT suppressed orthotopic transplantation tumor growth and induced tumor apoptosis. Taken together, these results suggest that 3-BrPA and SCT selectively suppress glycolytic enzymes, decrease ATP production, induce mitochondrial-mediated apoptosis, downregulate survivin, and inhibit tumor growth. Moreover, an intraperitoneal injection is an effective form of administration of 3-BrPA and SCT.

3-Bromopyruvate inhibits human gastric cancer tumor growth in nude mice via the inhibition of glycolysis.

Tumor cells primarily depend upon glycolysis in order to gain energy. Therefore, the inhibition of glycolysis may inhibit tumor growth. Our previous study demonstrated that 3-bromopyruvate (3-BrPA) inhibited gastric cancer cell proliferation in vitro. However, the ability of 3-BrPA to suppress tumor growth in vivo, and its underlying mechanism, have yet to be elucidated. The aim of the present study was to investigate the inhibitory effect of 3-BrPA in an animal model of gastric cancer. It was identified that 3-BrPA exhibited strong inhibitory effects upon xenograft tumor growth in nude mice. In addition, the antitumor function of 3-BrPA exhibited a dose-effect association, which was similar to that of the chemotherapeutic agent, 5-fluorouracil. Furthermore, 3-BrPA exhibited low toxicity in the blood, liver and kidneys of the nude mice. The present study hypothesized that the inhibitory effect of 3-BrPA is achieved through the inhibition of hexokinase activity, which leads to the downregulation of B-cell lymphoma 2 (Bcl-2) expression, the upregulation of Bcl-2-associated X protein expression and the subsequent activation of caspase-3. These data suggest that 3-BrPA may be a novel therapy for the treatment of gastric cancer.

Inhibitory effects of 3-bromopyruvate on human gastric cancer implant tumors in nude mice.

BACKGROUND: Gastric cancer is a common malignant tumor. Our previous study demonstrated inhibitory effects of 3-bromopyruvate (3-BrPA) on pleural mesothelioma. Moreover, we found that 3-BrPA could inhibit human gastric cancer cell line SGC-7901 proliferation in vitro, but whether similar effects might be exerted in vivo have remained unclear. AIM: To investigate the effect of 3-BrPA to human gastric cancer implant tumors in nude mice. MATERIALS AND METHODS: Animals were randomly divided into 6 groups: 3-BrPA low, medium and high dose groups, PBS negative control group 1 (PH7.4), control group 2 (PH 6.8-7.8) and positive control group receiving 5-FU. The TUNEL method was used to detect apoptosis, and cell morphology and structural changes of tumor tissue were observed under transmission electron microscopy (TEM). RESULTS: 3-BrPA low, medium, high dose group, and 5-FU group, the tumor volume inhibition rates were 34.5%, 40.2%, 45.1%, 47.3%, tumor volume of experimental group compared with 2 PBS groups (p<0.05), with no significant difference between the high dose and 5-FU groups (p>0.05). TEM showed typical characteristics of apoptosis. TUNEL demonstrated apoptosis indices of 28.7%, 39.7%, 48.7% for the 3-BrPA low, medium, high dose groups, 42.2% for the 5-FU group and 5% and 4.3% for the PBS1 (PH7.4) and PBS2 (PH6.8-7.8) groups. Compared each experimental group with 2 negative control groups, there was significant difference (p<0.05); there was no significant difference between 5-FU group and medium dose group (p>0.05), but there was between the 5-FU and high dose groups (p<0.05). CONCLUSIONS: This study indicated that 3-BrPA in vivo has strong inhibitory effects on human gastric cancer implant tumors in nude mice .