Hepatitis B viruses (HBV) specifically target the liver, where they efficiently infect quiescent hepatocytes. Thus, HBV virus has potential to be used as vectors for liver-directed gene transfer. We constructed a new HBV-based vector system. It is composed of transfer vector for transferring a foreign gene, green fluorescence protein (GFP) gene, and a helper vector. When the transfer vector and the helper vector were cotransfected into HepG2 cells, the recombinant HBV (rHBV) particles were generated by trans-complementation between two vectors. The rHBV particles carrying the foreign gene were identified by the Southern blot assay. To test gene delivery and the transduction of the rHBV, we infected primary human hepatocytes and immortalized, HepG2 cells with rHBV in vitro. The results using fluorescence microscopy confirmed that the inserted GFP gene was successfully transferred and expressed both in primary human hepatocytes and HepG2 cells.

The epider mal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), gefitinib, is an effective therapeutic drug used in the treatment of non-small cell lung cancers (NSCLCs) harboring EGFR mutations. However, acquired resistance significantly limits the efficacy of EGFR-TKIs and consequently, the current chemotherapeutic strategies for NSCLCs. It is, therefore, necessary to overcome this resistance. In the present study, the anticancer potential of natural extracts of Coptis chinensis (ECC) against gefitinib-resistant (GR) NSCLC cells were investigated in vitro and in vivo. ECC inhibited the viability, migration and invasion, and effectively induced the apoptosis of GR cells. These effects were associated with the suppression of EGFR/AKT signaling and the expression of anti-apoptotic proteins, Mcl-1 and Bcl-2, which were overexpressed in GR NSCLC cells. Combination treatment with ECC and gefitinib enhanced the sensitivity of GR cells to gefitinib in vitro, but not in vivo. However, ECC increased the survival of individual zebrafish without affecting the anticancer effect to cancer cells in vivo, which indicated a specific cytotoxic effect of ECC on cancer cells, but not on normal cells; this is an important property for the development of novel anticancer drugs. On the whole, the findings of the present study indicate the potential of ECC for use in the treatment of NSCLC, particularly in combination with EGFR-TKI therapy, in EGFR-TKI-resistant cancers.

Functional composition of tumor micro-environment (TME) has been regarded as one of the most important factors in tumor progression. Cancer cells induce immune suppressive condition in TME in order to evade immune system as well as to promote metastasis. Axl, Mer and CSF1R play important roles in making tumor friendly TME by increasing regulatory T cells (Tregs), M2 macrophages, myeloid-derived suppression cells (MDSCs) and suppressing antigen presentation. On the other hand, in cancer cells, overexpression of Axl is reported to have correlation with poor prognosis of patients through promoting epithelial-to-mesenchymal transition (EMT) and inducing drug resistance to chemo or targeted therapy. Q702 is an orally available selective Axl, Mer and CSF1R triple kinase inhibitor under IND enabling studies. In this poster, we present dual potentials of Q702 leading to tumor regression through: 1) immune stimulating activities of Q702 through decreasing Tregs, M2 macrophages, MDSCs population and promoting antigen presentation, 2) direct cytotoxic activity in tumor models including acute myeloid leukemia (AML) and EGFR TKI resistant non-small cell lung cancer (NSCLC). Citation Format: Yeong-In Yang, Hwankyu Kang, Dongsik Park, Yeejin Jeon, Jeongjun Kim, Baejung Choi, Jaeseung Kim, Jinkyung Rho, Jaecheol Lee, Kiyean Nam. Q702, selective Axl, Mer and CSF1R triple kinase inhibitor with dual potentials leading to tumor regression: Immuno-oncology therapy and targeted cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4139.