Background: Cancer cells reprogram their metabolism to meet specific bioenergetic/biosynthetic needs. Abnormal expression of energy metabolism enzymes may sustain aggressive phenotypes, therapeutic resistance and it may disclose novel therapeutic targets. We analyzed mRNA expression of glucose metabolism, key-enzyme genes in normal mucosa (NM), primary tumor (PT) and liver metastasis (LM) of CRC patients (pts) who underwent surgery and systemic therapy for advanced disease. Methods: Tissues of chemotherapy-naive, non-diabetic CRC pts were retrospectively studied by RT-qPCR for mRNA expression of the following genes: hexokinase-1 (HK1) and 2 (HK2), embryonic pyruvate kinase (PKM2), lactate dehydrogenase-A (LDH-A),glucose transporter-1 (SLC2A), voltage-dependent anion-selective channel protein-1 (VDAC1). The RT-qPCR ΔCt values (Cttarget–Ctreference) were used for calculating the expression level of each target gene with B2M and GUSB adopted as reference genes. A preliminary assessment was planned in a random sample of 24/72 enrolled pts (33%) to verify whether differences were detectable. T-test (Tt) and Wilcoxon test (Wt) were used for comparing ΔCt values between tissues (PT versus NM, LM versus NM, PT versus LM). Results: In the 24 pts, assays repeated with B2M and GUSB showed higher PT mRNA expression than NM for HK1 (Tt p = 0.0001; Wt p = 0.0004), LDH-A (Tt p < 0.0001, Wt p < 0.0001), PKM2 (Tt p < 0.0001, Wt p < 0.0001), SCL2A (Tt p < 0.0001, Wt p < 0.0001), VDAC1(Tt p = 0.0002, Wt p = 0.0004). The same significant associations were found when comparing LM versus NM tissues. There was a trend for higher mRNA expression of these genes in LM than in PT, but at this stage differences did not reach statistical significance. Conclusions: These results indicate enhanced glucose uptake (SCL2A, HK), glycolysis (LDH, PKM2) and mithocondrial trafficking (VDAC1) in CRC. Final analysis will include correlations with RAS/RAF mutational status and survival outcomes.
Glucose metabolism enzymes gene expression analysis and selective metabolic advantage in the progression of colorectal cancer (CRC)
RUZZO, ANNAMARIA;GIACOMINI, ELISA;MAGNANI, MAURO
2015
Abstract
Background: Cancer cells reprogram their metabolism to meet specific bioenergetic/biosynthetic needs. Abnormal expression of energy metabolism enzymes may sustain aggressive phenotypes, therapeutic resistance and it may disclose novel therapeutic targets. We analyzed mRNA expression of glucose metabolism, key-enzyme genes in normal mucosa (NM), primary tumor (PT) and liver metastasis (LM) of CRC patients (pts) who underwent surgery and systemic therapy for advanced disease. Methods: Tissues of chemotherapy-naive, non-diabetic CRC pts were retrospectively studied by RT-qPCR for mRNA expression of the following genes: hexokinase-1 (HK1) and 2 (HK2), embryonic pyruvate kinase (PKM2), lactate dehydrogenase-A (LDH-A),glucose transporter-1 (SLC2A), voltage-dependent anion-selective channel protein-1 (VDAC1). The RT-qPCR ΔCt values (Cttarget–Ctreference) were used for calculating the expression level of each target gene with B2M and GUSB adopted as reference genes. A preliminary assessment was planned in a random sample of 24/72 enrolled pts (33%) to verify whether differences were detectable. T-test (Tt) and Wilcoxon test (Wt) were used for comparing ΔCt values between tissues (PT versus NM, LM versus NM, PT versus LM). Results: In the 24 pts, assays repeated with B2M and GUSB showed higher PT mRNA expression than NM for HK1 (Tt p = 0.0001; Wt p = 0.0004), LDH-A (Tt p < 0.0001, Wt p < 0.0001), PKM2 (Tt p < 0.0001, Wt p < 0.0001), SCL2A (Tt p < 0.0001, Wt p < 0.0001), VDAC1(Tt p = 0.0002, Wt p = 0.0004). The same significant associations were found when comparing LM versus NM tissues. There was a trend for higher mRNA expression of these genes in LM than in PT, but at this stage differences did not reach statistical significance. Conclusions: These results indicate enhanced glucose uptake (SCL2A, HK), glycolysis (LDH, PKM2) and mithocondrial trafficking (VDAC1) in CRC. Final analysis will include correlations with RAS/RAF mutational status and survival outcomes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
