Lysyl oxidase and hypoxia-inducible factor 1α: biomarkers of gastric cancer

BACKGROUND Gastric cancer (GC) is one of the main causes of cancer mortality worldwide. Recent studies on tumor microenvironments have shown that tumor metabolism exerts a vital role in cancer progression. AIM To investigate whether lysyl oxidase (LOX) and hypoxia-inducible factor 1 alpha (HIF1 alpha) are prognostic and predictive biomarkers in GC. METHODS A total of 86 tissue and blood samples were collected from 140 patients admitted to our hospital between August 2008 and March 2012. Immunohistochemical staining was performed to measure the expression of LOX and HIF1 alpha in tumor and adjacent tissues collected from patients with GC. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis was used to detect the mRNA expression levels of LOX and HIF1 alpha in patients with GC. In addition, single-factor analysis was applied to analyze the relationship between LOX, HIF1 alpha and prognosis of GC. RESULTS Immunohistochemical staining suggested that the expression levels of LOX and HIF1 alpha increased in tumor tissues from patients with GC. QRT-PCR analysis indicated that mRNA expression of LOX and HIF1 alpha was also upregulated in tumor tissues, which was in accordance with the above results. We also detected expression of these two genes in blood samples. The expression level of LOX and HIF1 alpha was higher in healthy controls than in patients with GC. Additional analysis showed that the expression level of LOX and HIF1 alpha was related to the clinicopathological characteristics of GC. Expression of LOX and HIF1 alpha increased with the number of lymph node metastases and later tumor-node-metastasis stages. Single-factor analysis showed that high expression of LOX and HIF1 alpha led to poor prognosis of patients with GC. CONCLUSION LOX and HIF1 alpha can be used as prognostic and predictive biomarkers for GC.