Expression of hypoxia-inducible factor-1α affects tumor proliferation and antiapoptosis in surgically resected lung cancer

Hypoxia-inducible factor (HIF)-1 is a transcription factor that allows cells to adapt to hypoxic situations. HIF-1 is known to control tissue proliferation, antiapoptosis, angiogenesis and glucose metabolism. Furthermore, HIF-1 is involved in the growth of numerous cancer types. The present study aimed to examine the expression of HIF-1α immunohistochemically in resected lung cancers. The present study included 216 consecutive patients with lung cancer who underwent resection between April 2013 and January 2015. The patients' clinicopathological data were summarized, including imaging findings, tumor pathological characteristics, and the patient's age, sex and smoking status. The intratumoral expression of HIF-1α, survivin, c-Myc and the Ki-67 proliferation index were evaluated immunohistochemically. The patients were divided into two groups, according to the expression of HIF-1α (low vs. high) and the clinicopathological characteristics of these groups were compared. It was revealed that HIF-1α expression was significantly associated with ground glass opacity ratio, maximum standardized uptake value index, histological type (squamous cell carcinoma), differentiation and lymphatic invasion. Regarding the immunohistochemical findings, HIF-1α expression was significantly correlated with the expression levels of c-Myc (P<0.01) and survivin (P<0.01). Furthermore, the Ki-67 proliferation index was significantly higher in high-HIF-1α tumors compared with in low-HIF-1α tumors (P=0.01). The multivariate analysis identified squamous cell carcinoma, high SUVmax and lymphatic invasion as significant and independent factors for high HIF-1α expression. In conclusion, HIF-1 was highly expressed in certain subgroups of lung cancer with specific histopathology and images. HIF-1α expression was associated with tumor proliferation and antiapoptosis in lung cancer.