Effectiveness of Antibody-Drug Conjugate (ADC): Results of In Vitro and In Vivo Studies.

BACKGROUND Human lung cancer is still the leading cause of cancer-related mortality around the world, although a variety of new therapies have been used in the treatment of this disease. Antibody-drug conjugate (ADC) has revolutionized the field of cancer therapy in recent decades. Unlike traditional chemotherapy that damages the healthy cells, ADC first utilizes monoclonal antibodies to bind tumor-specific antigen targets and then deliver a highly potent cytotoxic agent to kill tumor cells. Thus, ADC can benefit cancer patients because this drug has less severe adverse effects. MATERIAL AND METHODS One type of ADC for non-small cell lung cancer (NSCLC) was designed in this study: Erbitux-vc-PAB-MMAE. It is a mouse/human chimeric monoclonal antibody, Erbitux, conjugating to the tubulin inhibitor auristatin. The efficacy of ADC was investigated through in vitro and in vivo studies. RESULTS Our in vitro study demonstrated that Erbitux-vc-PAB-MMAE could effectively inhibit proliferation of human lung cancer A549 cells, and arrested cell cycle at G2/M phase. In a mouse xenograft model, the results indicated that Erbitux-vc-PAB-MMAE could be exactly delivered to tumor tissues, and effectively inhibited tumor growth via promoting apoptosis of cancer cells. CONCLUSIONS The antibody portion of an ADC drug (Erbitux) was used as a vector to bring the effector molecule (tubulin inhibitor MMAE) to the targeted tumor tissue. This antibody-drug conjugate can exert a strong anti-tumor effect.

On-line comprehensive two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography for preparative isolation of Peucedanum praeruptorum.

A new on-line comprehensive preparative two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography (2D NPLC × RPLC) system was developed for the separation of complicated natural products. It was based on the use of a silica gel packed medium-pressure column as the first dimension and an ODS preparative HPLC column as the second dimension. The two dimensions were connected with normal-phase (NP) and reversed-phase (RP) enrichment units, involving a newly developed airflow assisted adsorption (AAA) technique. The instrument operation and the performance of this NPLC × RPLC separation method were illustrated by gram-scale isolation of ethanol extract from the roots of Peucedanum praeruptorum. In total, 19 compounds with high purity were obtained via automated multi-step preparative separation in a short period of time using this system, and their structures were comprehensively characterized by ESI-MS, (1)H NMR, and (13)C NMR. Including two new compounds, five isomers in two groups with identical HPLC and TLC retention values were also obtained and identified by 1D NMR and 2D NMR. This is the first report of an NPLC × RPLC system successfully applied in an on-line preparative process. This system not only solved the interfacing problem of mobile-phase immiscibility caused by NP and RP separation, it also exhibited apparent advantages in separation efficiency and sample treatment capacity compared with conventional methods.