HGFK1 is associated with a better prognosis and reverses inhibition by gefitinib in NSCLC cases.

Purpose: Non small cell lung cancer (NSCLC) is the leading worldwide source of cancer-related deaths. Although some drugs targeting EGFR mutations have been developed, most advanced cases are still incurable. New targets for anticancer drugs are demanded. The kringle 1 domain of hepatocellular growth factor alpha chain (HGFK1) is a potent anti-angiogenesis factor. It has also emerged as a potential anticancer factor in hepatocellular carcinoma (HCC). The expression of HGFK1 protein in patients with NSCLC has not been reported to date.

Method: Here, we assessed HGFK1 expression by Western blotting in 103 cases with advanced NSCLC to investigate the impact of HGFK1 on survival.

Results: Results revealed 33 (30.1%) patients were classified as high expressors, this being significantly associated with less remote metastasis (P = 0.002) but not with lymph node metastasis (P = 0.062). There was also a significant association between HGFK1 expression and tumor size (P = 0.025) as well as clinical stage (P = 0.012). Kaplan-Meier survival analysis showed that both overall survival (OS) and progression free survival (PFS) of patients with HGFK1 expression were longer than those of patients without HGFK1 expression (P = 0.004 and P = 0.001 respectively). HGFK1 reversed gefitinib inhibition in the resistant NSCLC cell line A431/GR but did not inhibit the proliferation of NSCLC cells A431 and A431/GR directly. Reversion of gefitinib inhibition in A431/GR cells by HGFK1 was related to decreased phosphorylation of ERK and STAT5.

Conclusions: HGFK1 may be a useful prognostic factor of advanced NSCLC patients and a potential drug for gefitinib resistant patients.