OPN-a splicing variant expression in non-small cell lung cancer and its effects on the bone metastatic abilities of lung cancer cells in vitro

Background: Osteopontin (OPN) is known to be involved in the development of certain cancers, including non-small cell lung cancer (NSCLC). However, its role in tumour progression remains unclear. The present study investigated the expression and biological impact of the OPN variant, OPN-a in NSCLC. Materials and Methods: OPN-a splicing variant expression in human NSCLC tissues was analyzed by real-time qPCR and immunohistochemistry (IHC), respectively. The impact of OPN-a on cellular functions of lung cancer cells was also evaluated. In addition, an in vitro model was developed for the assessment of interactions between lung cancer cells and bone tissue. Results: The expression of OPN-a was higher in lung cancer tissues compared to normal controls. OPN-a promoted the malignant phenotypes of A549 cells by enhancing cell-adherent abilities to bone tissues, which could be mediated by the interaction with the cell surface receptor αvβ3 integrin. Conclusion: OPN-a may represent a bone metastatic factor in human lung cancer, as well as a potential therapy target.