Upregulation of HOXA11 during the progression of lung adenocarcinoma detected via multiple approaches

The altered expression of homeobox (HOX)A11 has been observed in various malignant tumor types, but it has remained to be determined in human lung adenocarcinoma (LUAD). In the present study, the expression of HOXA11 in LUAD and the potential associated mechanisms were assessed. Data from The Cancer Genome Atlas and Oncomine microarrays were gathered and in-house polymerase chain reaction data were produced to investigate the altered expression of HOXA11 in LUAD and its association with various clinicopathological characteristics. Genes co-expressed with HOXA11 were also identified by searching the cBioPortal and Multi Experiment Matrix databases, and performing a bioinformatics analysis, through which the potential molecular mechanisms of HOXA11 in LUAD were explored. The data analyses indicated that HOXA11 was overexpressed in the LUAD samples, and together with its co-expressed genes, it was indicated to participate in various key signaling pathways, including the focal adhesion, extracellular matrix-receptor interaction, axon guidance and small cell lung cancer signaling pathways. Furthermore, collagen type III α 1 chain (COL3A1), ephrin B2 (EFNB2), integrin subunit α 8 (ITGA8) and syndecan 2 (SDC2) were confirmed to be differentially expressed in LUAD vs. normal controls at the mRNA and protein level. Of note, LUAD patients with low expression of HOXA11 and ITGB1 had better overall survival rates. The present study indicated that HOXA11 may function as an oncogene in LUAD, and HOXA11 protein probably combines with ITGB1, COL3A1, EFNB2, ITGA8 and SDC2 to have a role in the focal adhesion pathway.