SPOCK1 contributes to the third-generation EGFR tyrosine kinase inhibitors resistance in lung cancer.

Explanation of the mechanism of resistance to third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and the development of a novel strategy for drug resistance are imperative in third-generation EGFR-TKIs-resistant non-small cell lung cancer (NSCLC). SPOCK1 was found to be abnormally expressed in various tumors including lung cancer, however, there was no study focused on the role of SPOCK1 in third-generation EGFR-TKIs resistant lung cancer cells. We investigated the roles of SPOCK1 in NSCLC with third-generation EGFR-TKIs resistance. We showed that SPOCK1 was upregulated in the osimertinib-resistant lung cancer cells and knockdown of SPOCK1 inhibits osimertinib-resistant cells growth and overcomes resistance. Furthermore, we demonstrated that the SPOCK1 was higher in clinical NSCLC specimens compared with the normal lung tissues, and the higher expression of SPOCK1 correlated with poor prognosis. In addition, the overexpression of SPOCK1 in NSCLC tissues was positively correlated with MMP11 and TGFβ1. Our study suggested that SPOCK1 could be an independent prognostic factor in NSCLC and would be a candidate for target therapy in osimertinib-resistant lung tumors.