Prognostic Significance of Glycolytic Metabolic Change Related to HIF-1alpha in Oral Squamous Cell Carcinomas

BACKGROUND: Growing tumors adapt to a hypoxic environment and increase anaerobic glycolysis. This metabolic switch is related to aggressive behavior. We investigated the relationship between glycolytic metabolism biomarkers associated with hypoxia-inducible factor (HIF)-1alpha and prognosis. METHODS: We performed immunohistochemical staining of HIF-1alpha, pyruvate dehydrogenase kinase (PDK) 1 and lactate dehydrogenase (LDH) 5 in 74 patients with oral squamous cell carcinoma (SCC) who had received curative radical resection. RESULTS: High reactivity of HIF-1alpha, PDK 1 and LDH 5 was observed in 29 (39.2%), 32 (43.2%) and 54 (73.0%) patients, respectively. Expression levels of the three biomarkers were significantly correlated. All three markers were highly expressed in 16 (21.6%) patients. Elevated expression of the three markers was associated with increased invasiveness (p = 0.043) and recurrence (p = 0.017) of tumors. In survival analysis, upregulation of the three markers was additionally associated with shorter disease free survival (DFS, p = 0.001) and overall survival (OS, p = 0.002). High expression of all three markers was a strong independent prognostic factor for DFS (p = 0.030) and OS (p = 0.026). CONCLUSIONS: Oral SCC with altered glycolytic metabolism exhibits a more invasive and aggressive phenotype. Our results indicate that glycolytic metabolism biomarkers related to HIF-1alpha may be independent prognostic factors in patients with oral SCC.

Expression of LDH-5 in Colorectal Carcinomas: Correlation with Prognosis and Tumor Angiogenesis

PURPOSE: Lactate dehydrogenase-5 (LDH-5) is one of five isoenzymes and is the most important for anaerobic glycolysis. LDH-5 is transcriptionally regulated by hypoxia-inducible factor (HIF). HIF plays a role in the response to hypoxia by activating genes involved in vascular remodeling, cell proliferation, and erythropoiesis. In this study, we investigated the clinicopathologic significance and angiogenesis of LDH-5 expression in colorectal cancer. METHODS: We retrospectively reviewed the medical records of 83 patients with colorectal cancer who underwent a surgical resection at Soonchunhyang Cheonan Hospital from January 2001 to December 2003. LDH-5 and HIF-1alpha protein expressions were evaluated in 83 human colorectal cancer specimens. These factors were related to TNM stage, lymph node metastasis, vascular, neural, and lymphatic invasion, and prognosis. RESULTS: LDH-5 was positive in 66% (55 patients) of the tumors, and HIF-1alpha was positive in 66% (55 patients) of the tumors. LDH-5 expression was significantly associated with HIF-1alpha protein expression (P<0.001). Also, LDH-5 expression was significantly associated with TNM stage and lymph node metastasis (P<0.001) while HIF-1alpha expression was significantly associated with TNM stage (P<0.001), lymph node metastasis (P<0.001), vascular invasion (P=0.011), and lymphatic invasion (P=0.005). The survival of the patients with high LDH-5 expression was worse than that of patients with low LDH-5 expression (P=0.032). CONCLUSION: Our study shows a high expression of LDH-5 in colorectal cancer. The up-regulation of LDH-5 parallels an increase in HIF-1alpha expression. The immunohistochemical assessment of tissue LDH-5 and HIF-1alpha provides important prognostic information for colorectal carcinomas.

Soluble expression and characterization of mouse lactate dehydrogenase-C4 in Escherichia coli / 解放军医学杂志

Objective A prokaryotic expression vector was constructed by inserting the coding sequence of mouse sperm specific lactate dehydrogenase C into pET-28a(+)and the recombinant mLDHC44 protein was purified by Ni+-NTA agrose.Methods The cDNA of mouse sperm specific lactate dehydrogenase C was obtained by RT-PCR,with total RNA of mouse testis tissues as templates.The coding sequence of mouse LDHC4 was amplified by PCR with specific primers.This recombinant vector was transformed into Escherichia coli BL21(DE3).The recombinant mLDHC4 protein was induced by isopropy-?-D-thiogalactoside(IPTG)and identified by sodium dodecyl sulfate polyacrylamide electrophoresis and LDH activity determination.After purified with Ni+-NTA agrose,the mLDHC4 protein was probed with antisera from the pVAX1-mLDHC4 vaccine(the eukaryotic expression vector of mouse sperm specific lactate dehydrogenase C)immunized BALB/c mice by Western blot analysis.Results After digested with BamH I-EcoR I,the recombinant plasmids produced right fragment which was about 1000bp.Sequencing showed that the sequence of the cloned fragment was in agreement with sequence in GenBank.This recombinant vector was named as pET-28a(+)-mLDHC4.With induction of IPTG,The recombinant protein with molecular weight of about 35 kD was expressed and the enzyme activity of this protein was high.After purified with Ni+-NTA agrose,this mLDHC4 protein formed a specific band by sodium dodecyl sulfate polyacrylamide electrophoresis and probed with antisera from immunized BALB/c mice and then formed a specific band in the nitrocellulose membrane.Conclusion The coding sequence of mouse lactate dehydrogenase subunit C had been cloned into the prokaryotic expression vector pET-28a(+)and the mLDHC4 protein could be expressed at a high level,the specificity of this protein was high and the activity was strong.