Lung cancer is the leading cause of cancer-related death worldwide. Most targeted drugs approved for lung cancer treatment are tyrosine kinase inhibitors (TKIs) directed against EGFR or ALK, and are used mainly for adenocarcinoma. At present, there is no effective or tailored targeting agent for large cell carcinoma (LCC) or small cell lung cancer (SCLC). Therefore, we aimed to identify targeting peptides with diagnostic and therapeutic utility that possess broad subtype specificity for SCLC and non-small cell lung cancer (NSCLC). We performed phage display biopanning of H460 LCC cells to select broad-spectrum lung cancer-binding peptides, since LCC has recently been categorized as an undifferentiated tumor type within other histological subcategories of lung cancer. Three targeting phages (HPC1, HPC2, and HPC4) and their respective displayed peptides (HSP1, HSP2, and HSP4) were able to bind to both SCLC and NSCLC cell lines, as well as clinical specimens, but not to normal pneumonic tissues. In vivo optical imaging of phage homing and magnetic resonance imaging (MRI) of peptide-SPIONs revealed that HSP1 was the most favorable probe for multimodal molecular imaging. Using HSP1-SPION, the T2-weighted MR signal of H460 xenografts was decreased up to 42%. In contrast to the tight binding of HSP1 to cancer cell surfaces, HSP4 was preferentially endocytosed and intracellular drug delivery was thereby effected, significantly improving the therapeutic index of liposomal drug in vivo. Liposomal doxorubicin (LD) conjugated to HSP1, HSP2, or HSP4 had significantly greater therapeutic efficacy than non-targeting liposomal drugs in NSCLC (H460 and H1993) animal models. Combined therapy with an HSP4-conjugated stable formulation of liposomal vinorelbine (sLV) further improved median overall survival (131 vs. 84 days; P = 0.0248), even in aggressive A549 orthotopic models. Overall, these peptides have the potential to guide a wide variety of tailored theranostic agents for targeting therapeutics, non-invasive imaging, or clinical detection of SCLC and NSCLC.

No abstract

Epithelial cell adhesion molecule (EpCAM) is known to be overexpressed in epithelial cancers associated with enhanced malignant potential, particularly colorectal carcinoma (CRC) and head and neck squamous cell carcinoma (HNSCC). However, it is yet to be determined whether targeting EpCAM can directly inhibit the progression of malignance. Here, we have generated six novel monoclonal antibodies (mAbs) against EpCAM; these antibodies specifically bind to CRC and HNSCC cells, but not normal cells. One EpCAM mAb, EpAb2-6, was found to induce cancer cell apoptosis in vitro, inhibit tumor growth, and prolong the overall survival of mice with human colon or oral carcinoma xenografts. EpAb2-6 also increases the therapeutic efficacy of irinotecan, fluorouracil, and leucovorin (IFL) therapy in tumor-bearing mice. Subsequent analysis suggested that EpAb2-6 can potentially inhibit the growth and proliferation of tumorspheres. Investigation of the mechanism by which EpAb2-6 inhibits tumor growth revealed that EpAb2-6 inhibits tumor-necrosis-factor α converting enzyme (TACE/ADAM17) and γ-secretase activation and blocks EpCAM intracellular domain (EpICD) cleavage, thus preventing the nuclear localization of EpICD. Furthermore, EpAb2-6, which binds to positions in the EGF-II/TY domain of EpCAM, inhibits production of EpICD, thereby decreasing translocation of β-catenin into the nucleus and activation of p53 and p21 expression. Collectively, our results indicate that novel EpCAM mAbs can potentially be used for cancer-targeted therapy. Citation Format: Han-Chung Wu, Yi-Hsuan Chi, Mei-Ying Liao. An effective anti-EpCAM antibody EpAb2-6 for the treatment of colon cancer and its underlying mechanisms. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2906. doi:10.1158/1538-7445.AM2014-2906

Despite the efforts made for osteoarthritis (OA) treatment, the results are limited and can be improved by enhancing the OA homing strategy. Here, we used a phage display system to identify OA-targeting peptides, and combined them with magnetic resonance imaging detection reagents to expand their application to early OA diagnosis in rat and swine models. OA-targeting peptides showed better static and kinetic friction characteristics than scrambled peptides, when conjugated with hyaluronic acid for rheological lubrication studies using human OA specimens. Furthermore, mesenchymal stem cells, through CD44 binding to hyaluronic acid conjugated with OA-targeting peptides, showed better capacity for OA homing and repair than those conjugated with scrambled peptides. Protein–peptide docking revealed WXPXW as the consensus binding motifs that bind to collagen XII, a protein exclusively expressed in human and animal OA models. These results suggest the potential of OA-targeting peptides to promote diagnosis, treatment, and regenerative medicine for OA.