0.05 was considered as statistically significant. 3. been found to be frequently overexpressed on the surfaces of liver cancer (LC) cells, which contributes to both the growth and metastasis of LC cells. Recently, the expression of GPC3 has been reported to be inversely associated with glucose metabolism activity in Nifuroxazide LC patients, suggesting that GPC3 may play a role in the regulation of glucose metabolism in LC. However, the role of GPC3 in glucose metabolism CEACAM8 reprogramming, as well as in LC cell growth and metastasis, is unknown. Here, we found that GPC3 significantly contributed to the reprogramming of glucose metabolism in LC cells. On the one hand, GPC3 enhanced the glycolysis of LC cells through upregulation of the glycolytic genes of Glut1, HK2, and LDH-A. On the other hand, GPC3 repressed mitochondrial respiration through downregulation of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1was involved in both GPC3-regulated upregulation of glycolytic genes of HK2, PKM2, and Glut1 and downregulation of mitochondrial biogenesis regulator PGC-1in LC cells. Additionally, GPC3-regulated reprogramming of glucose metabolism played a critical role in the growth and metastasis of LC cells. 0.05 was considered as statistically significant. 3. Results 3.1. GPC3 Enhanced Nifuroxazide the Warburg Effect in Liver Malignancy Cells To study the part of GPC3 in the rules of LC cell glucose metabolism, we founded LC cell Nifuroxazide lines that differ only in their GPC3 status. HLE cells with relatively high GPC3 manifestation (Numbers and ) were transfected with nontargeting siRNA (siCtrl) or two siRNA focusing on GPC3 (si-GPC3#1 and si-GPC3#2) for the establishment of GPC3 knockdown cell models, and HLF cells with relatively low GPC3 manifestation were transfected with an empty vector (EV) or an expression vector encoding GPC3 (GPC3) for the establishment of GPC3 overexpression cell models (Numbers 1(a) and 1(b)). Our results showed that GPC3 knockdown HLE cells (si-GPC3#1 and si-GPC3#2) exhibited much lower cellular glucose uptake and lactate production, while higher pH value in the tradition medium compared with the control cells (siCtrl). In contrast, HLF cells with GPC3 overexpression (GPC3) displayed significantly higher cellular glucose uptake and lactate production, while lower pH value in the tradition medium compared with the control cells (EV) (Numbers 1(c)C1(e)). Open in a separate window Number 1 GPC3 enhanced the Warburg effect in LC cells. (a and b) Knockdown or overexpression of GPC3 in HLE and HLF cells was confirmed by quantitative real-time PCR (qRT-PCR) and western blot analysis at mRNA and protein levels. (c) Glucose uptake was measured in HLE and HLF cells transfected with siRNAs or manifestation vectors as indicated (si-GPC3#1 and si-GPC3#2, siRNAs against GPC3; siCtrl, control siRNA; GPC3, manifestation vector encoding GPC3; EV, vacant vector). (d). Lactate production was measured in HLE and HLF cells with treatment as indicated. (e) The pH value in the tradition medium was measured in HLE and HLF cells with treatment as indicated. (f) Oxygen consumption rate (OCR) was measured in HLE and HLF cells with treatment as indicated. (g) Relative enzyme activities of respiratory complexes ICV were measured in HLE and HLF cells with treatment as indicated. Data demonstrated are the imply??SEM from three independent experiments. 0.05; 0.01. Improved glycolysis in tumor cells is definitely always accompanied by decreased mitochondrial oxidative phosphorylation (OXPHOS) . We therefore hypothesized that mitochondrial OXPHOS in LC cells may be inhibited by GPC3. To test that, the effect of GPC3 on mitochondrial respiration was further examined. As demonstrated in Numbers 1(f) and 1(g), HLE cells with GPC3 knocked down (si-GPC3#1 and si-GPC3#2) exhibited a significantly higher oxygen usage rate and improved activities of respiratory chain complexes ICV than control cells (siCtrl), whereas HLF cells with pressured manifestation of GPC3 (GPC3) displayed a clearly lower oxygen usage rate and decreased activities of respiratory chain complexes ICV than control cells (EV). Collectively, these results indicate that GPC3 takes on an important part in the promotion of the Warburg effect in Nifuroxazide LC cells. 3.2. GPC3 Enhanced the Warburg Effect through Upregulation of Nifuroxazide Glycolytic Enzymes To explore the underlying mechanisms of GPC3 in the promotion of glycolysis, we 1st analyzed the expressions of the key glycolytic enzymes including Glut1, HK2, and LDH-A in HLE and HLF cells with different GPC3 levels. As demonstrated in Numbers 2(a) and 2(b), knockdown.