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The globo-series glycosphingolipids (SSEA3, SSEA4, and Globo H) were shown to express in many cancers selectively, and a combination of anti-SSEA4 and anti-Globo H antibodies was able to suppress tumor growth in mice inoculated with breast cancer cell lines. To further understand the effect, we focused on the combined effect of the two antibodies in target binding and antibody-dependent cellular cytotoxicity (ADCC) in vitro. Here, we report that the binding of anti-Globo H antibody (VK9) to MDA-MB231 breast cancer cells was influenced by anti-SSEA4 antibody (MC813-70), and a combination of both antibodies induced a similar effect as did anti-SSEA4 antibodies alone in a reporter-based ADCC assay, indicating that SSEA4 is a major target in breast cancer due to its higher expression than Globo H. Furthermore, we showed that a homogeneous anti-SSEA4 antibody (chMC813-70-SCT) designed to maximize the ADCC activity can be used to isolate a subpopulation of natural killer (NK) cells that exhibit an ∼23% increase in killing the target cells as compared to the unseparated NK cells. These findings can be used to predict a therapy outcome based on the expression levels of antigens and evaluate therapeutic antibody development.

Ovarian cancer has a high recurrence rate after platinum‐based chemotherapy. To improve the treatment of ovarian cancer and identify ovarian cancer‐specific antibodies, we immunized mice with the human ovarian carcinoma cell line, SKOV‐3, and generated hybridoma clones. Several rounds of screening yielded 30 monoclonal antibodies (mAbs) with no cross‐reactivity to normal cells. Among these mAbs, OV‐Ab 30‐7 was found to target integrin α3 and upregulate p53 and p21, while stimulating the apoptosis of cancer cells. We further found that binding of integrin α3 by OV‐Ab 30‐7 impaired laminin‐induced focal adhesion kinase phosphorylation. The mAb alone or in combination with carboplatin and paclitaxel inhibited tumor progression and prolonged survival of tumor‐bearing mice. Moreover, immunohistochemical staining of ovarian patient specimens revealed higher levels of integrin α3 in cancer cells compared with normal cells. By querying online clinical databases, we found that elevated ITGA3 expression in ovarian cancer is associated with poor prognosis. Taken together, our data suggest that the novel mAb, OV‐Ab 30‐7, may be considered as a potential therapeutic for ovarian cancer., The novel mAb, OV‐Ab 30‐7, can induce ovarian cancer cell apoptosis, and blockage integrin‐laminin signaling, and may be considered as a potential therapeutic for ovarian cancer.

Vascular endothelial growth factor receptor 2 (VEGFR2) is highly expressed in tumor‐associated endothelial cells, where it modulates tumor‐promoting angiogenesis, and it is also found on the surface of tumor cells. Currently, there are no Ab therapeutics targeting VEGFR2 approved for the treatment of prostate cancer or leukemia. Therefore, development of novel efficacious anti‐VEGFR2 Abs will benefit cancer patients. We used the Institute of Cellular and Organismic Biology human Ab library and affinity maturation to develop a fully human Ab, anti‐VEGFR2‐AF, which shows excellent VEGFR2 binding activity. Anti‐VEGFR2‐AF bound Ig‐like domain 3 of VEGFR2 extracellular region to disrupt the interaction between VEGF‐A and VEGFR2, neutralizing downstream signaling of the receptor. Moreover, anti‐VEGFR2‐AF inhibited capillary structure formation and exerted Ab‐dependent cell‐mediated cytotoxicity and complement‐dependent cytotoxicity in vitro. We found that VEGFR2 is expressed in PC‐3 human prostate cancer cell line and associated with malignancy and metastasis of human prostate cancer. In a PC‐3 xenograft mouse model, treatment with anti‐VEGFR2‐AF repressed tumor growth and angiogenesis as effectively and safely as US FDA‐approved anti‐VEGFR2 therapeutic, ramucirumab. We also report for the first time that addition of anti‐VEGFR2 Ab can enhance the efficacy of docetaxel in the treatment of a prostate cancer mouse model. In HL‐60 human leukemia‐xenografted mice, anti‐VEGFR2‐AF showed better efficacy than ramucirumab with prolonged survival and reduced metastasis of leukemia cells to ovaries and lymph nodes. Our findings suggest that anti‐VEGFR2‐AF has strong potential as a cancer therapy that could directly target VEGFR2‐expressing tumor cells in addition to its anti‐angiogenic action., Affinity‐maturated anti‐vascular endothelial growth factor receptor 2 (VEGFR2) therapeutic Ab has strong clinical potential for cancer treatment due to its simultaneous inhibition of tumor angiogenesis in vascular endothelial cells and tumorigenesis in VEGFR2‐expressing tumor cells.

The viral E proteins of dengue virus (DENV) and Zika virus (ZIKV) are the major viral proteins involved in receptor binding and fusion, and for the induction of protective antibodies against viral infections. DIII of the E proteins is an independent domain and stretches out on the virion surface that can elicit type-specific neutralizing antibodies. For recombinant DIII vaccine development, prime-boost immunizations can provide an advantage of eliciting more type-specific neutralizing antibodies by recalling DIII antigens after DIII booster to improve protection. Methods: The DIII of the E genes of DENV and ZIKV were fused with bacterial fliC gene for the expression of flagellin-DIII (FliC-DIII) fusion proteins. Prime-boost immunization strategies by the second-dose booster of four DENV serotype or ZIKV FliC-DIII fusion proteins were used to investigate the induction of neutralizing antibodies and protection against viral infections. Cross-reactive non-neutralizing antibodies in each group of antisera were also examined using in vitro antibody-dependent enhancement (ADE) assay. A series of glycan-masking E antigens were finally constructed for prime-boost immunizations to abolish the elicitation of cross-reactive non-neutralizing antibodies for ADE activity. Results: We showed that inclusion of a bivalent live-attenuated vaccine with a FliC-DIII booster is superior in eliciting neutralization titers and protection in vivo against all four-serotype DENVs. We also demonstrated that recombinant adenovirus vectors encoding four-serotype DENV prMEs with a FliC-DIII prime-boost scheme is capable of eliciting good antibody responses. In contract, recombinant adenovirus vector of ZIKV prME gene priming, followed by ZIKV FliC-DIII booster did not improve vaccine efficacy. The glycan-masking mutation on the ZIKV E protein ij loop (E-248NHT), but not on DENV2 E protein ij loop (E-242NHT), resulted in abolishing the elicitation of cross-reactive antibodies for DENV and ZIKV infection enhancements. Conclusions: Our findings can provide useful information for designing novel immunogens and vaccination strategies in an attempt to develop a safe and efficacious DENV or ZIKV vaccine.

Epithelial cell adhesion molecule (EpCAM) is highly expressed in colon cancers, but its role in cancer progression remains to be elucidated. In this work, we found that the extracellular domain of EpCAM (EpEX) activated EGFR and downstream ERK1/2 signaling to promote colon cancer cell migration and proliferation, as well as tumor growth. Mechanistically, we discovered that EpEX-EGFR-ERK1/2 signaling positively regulated intramembrane proteolysis (RIP) of EpCAM and shedding of the intracellular domain (EpICD). Treatment with an EGFR inhibitor ablated the EpEX-induced phosphorylation of ERK1/2 and AKT. Additionally, treatment with inhibitors of either EGFR or MEK decreased EpEX-induced EpICD shedding and further revealed that EpICD is necessary for nuclear accumulation of β-catenin and the induction of HIF1α target gene expression in vitro and in vivo. Moreover, an anti-EpCAM neutralizing monoclonal antibody, EpAb2-6, inhibited the nuclear translocation of EpICD and β-catenin and induced apoptosis in colon cancer cells. Importantly, analysis of colorectal cancer tissues showed that nuclear accumulation of EpICD was highly correlated with metastasis and poor prognosis, suggesting that it may play an important functional role in cancer progression. Thus, we provide novel insights into the mechanisms and functions of EpEX-mediated signaling, which may be considered as a promising target for the treatment of colon cancer.

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.

Dengue virus (DENV) circulates in tropical and subtropical areas around the world, where it causes high morbidity and mortality. There is no effective treatment of infection, with supportive care being the only option. Furthermore, early detection and diagnosis are important to facilitate clinical decisions. In this study, seven monoclonal antibodies (mAbs) recognizing nonstructural protein 1 (NS1) of DENV were generated by hybridoma techniques. These antibodies can be divided into two groups: serotype-specific (DB6-1, DB12-3, and DB38-1) and nonspecific (consisting of antibodies DB16-1, DB20-6, DB29-1, and DB41-2). The B-cell epitopes of DB20-6 and DB29-1 were identified by phage display and site-directed mutagenesis, and its binding motif, WXXWGK, was revealed to correspond to amino acid residues 115-120 of the DENV-2 NS1 protein. A diagnostic platform, consisting of a serotype-specific capture antibody and a complex detection antibody, exhibited a detection limit of about 1 ng/mL, which is sufficient to detect NS1 in clinical serum samples from dengue patients. This diagnostic platform displayed better specificity and sensitivity than two examined commercial NS1 diagnostic platforms. In summary, our results indicate that these newly generated mAbs are suitable for detection of NS1 protein of DENV-2 in clinical samples.

Mutation of KRAS in non-small-cell lung cancer (NSCLC) shows a poor response to epidermal growth factor receptor (EGFR) inhibitors and chemotherapy. Currently, there are no direct anti-KRAS therapies available. Thus, new strategies have emerged for targeting KRAS downstream signaling. Panobinostat is a clinically available histone deacetylase inhibitor for treating myelomas and also shows potentiality in NSCLC. However, the therapeutic efficacy of panobinostat against gefitinib-resistant NSCLC is unclear. In this study, we demonstrated that panobinostat overcame resistance to gefitinib in KRAS-mutant/EGFR-wild-type NSCLC. Combined panobinostat and gefitinib synergistically reduced tumor growth in vitro and in vivo. Mechanistically, we identified that panobinostat-but not gefitinib-inhibited TAZ transcription, and the combination of panobinostat and gefitinib synergistically downregulated TAZ and TAZ downstream targets, including EGFR and EGFR ligand. Inhibition of TAZ by panobinostat or short hairpin RNA sensitized KRAS-mutant/EGFR-wild-type NSCLC to gefitinib through abrogating AKT/mammalian target of rapamycin (mTOR) signaling. Clinically, TAZ was positively correlated with EGFR signaling, and coexpression of TAZ/EGFR conferred a poorer prognosis in lung cancer patients. Our findings identify that targeting TAZ-mediated compensatory mechanism is a novel therapeutic approach to overcome gefitinib resistance in KRAS-mutant/EGFR-wild-type NSCLC.

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.

Dengue fever is caused by four different serotypes of dengue virus (DENV) which is the leading cause of worldwide arboviral diseases in humans. Virus-like particles (VLPs) containing flavivirus prM/E proteins have been demonstrated to be a potential vaccine candidate; however, the structure of dengue VLP is poorly understood. Herein VLP derived from DENV serotype-2 were engineered becoming highly matured (mD2VLP) and showed variable size distribution with diameter of ~31 nm forming the major population under cryo-electron microscopy examination. Furthermore, mD2VLP particles of 31 nm diameter possess a T = 1 icosahedral symmetry with a groove located within the E-protein dimers near the 2-fold vertices that exposed highly overlapping, cryptic neutralizing epitopes. Mice vaccinated with mD2VLP generated higher cross-reactive (CR) neutralization antibodies (NtAbs) and were fully protected against all 4 serotypes of DENV. Our results highlight the potential of ‘epitope-resurfaced’ mature-form D2VLPs in inducing quaternary structure-recognizing broad CR NtAbs to guide future dengue vaccine design.

In patients who survive myocardial infarction, many go on to develop congestive heart failure (CHF). Despite ongoing efforts to develop new approaches for postinfarction therapy, there are still no effective therapeutic options available to CHF patients. Currently, the delivery of cardioprotective drugs relies entirely on passive uptake via the enhanced permeability and retention (EPR) effect which occurs in proximity to the infarction site. However, in ischemic disease, unlike in cancer, the EPR effect only exists for a short duration postinfarction and thus insufficient for meaningful cardioprotection. Splenic monocytes are recruited to the heart in large numbers postinfarction, and are known to interact with platelets during circulation. Therefore, the strategy is to exploit this interaction by developing platelet-like proteoliposomes (PLPs), biomimicking platelet interactions with circulating monocytes. PLPs show strong binding affinity for monocytes but not for endothelial cells in vitro, mimicking normal platelet activity. Furthermore, intravital multiphoton imaging shows that comparing to plain liposomes, PLPs do not aggregate on uninjured endothelium but do accumulate at the injury site 72 h postinfarction. Importantly, PLPs enhance the targeting of anti-inflammatory drug, cobalt protoporphyrin, to the heart in an EPR-independent manner, which result in better therapeutic outcome.

While there has been extensive development of anti-cancer drugs for treatment of prostate cancer, the therapeutic efficacy of such drugs remains inadequate in many cases. Here, we performed in vitro biopanning of the PC3 human prostate carcinoma cell line to select prostate cancer-specific peptides by phage display. We successfully identified specific peptides targeting prostate cancer cells, and their specificity was confirmed by cellular ELISA and flow cytometry. Moreover, we found that the phage clones also recognize other prostate cancer cell lines and surgical specimens from prostate cancer patients. The tumor targeting ability of these phages was validated in a xenograft model, in which high accumulation of targeting phage was observed. To investigate whether selected peptides are able to target tumors and enhance drug delivery into cancer cells, we synthesized peptide-PEGylated lipids and post-inserted them into preformed liposomal doxorubicin and vinorelbine. The results of our cellular uptake and MTT assays indicate that peptide-conjugated liposomes exhibit enhanced drug intracellular delivery and cytotoxicity. The conjugation of targeting peptide to imaging agents, such as quantum dots (QDs) and superparamagnetic iron oxide nanoparticles (SPIONs), results in more precise delivery of these agents to tumor sites. Furthermore, administration of liposomal doxorubicin and vinorelbine conjugated with targeting peptides was found to markedly increase the inhibition of human prostate tumor growth in mouse xenograft and orthotopic models. These results indicate that targeting peptide, SP204, has significant potential for targeted therapy and molecular imaging in prostate cancer.

It is more challenging to design peptide drugs than small molecules through molecular docking and in silico analysis. Here, we developed a structure-based approach with various computational and analytical techniques to optimize cancer-targeting peptides for molecular imaging and therapy. We first utilized a peptide-binding protein database to identify GRP78, a specific cancer cell-surface marker, as a target protein for the lead, L-peptide. Subsequently, we used homologous modeling and molecular docking to identify a peptide-binding domain within GRP78 and optimized a series of peptides with a new protein-ligand scoring program, HotLig. Binding of these peptides to GRP78 was confirmed using an oriented immobilization technique for the Biacore system. We further examined the ability of the peptides to target cancer cells through in vitro binding studies with cell lines and clinical cancer specimens, and in vivo tumor imaging and targeted chemotherapeutic studies. MicroSPECT/CT imaging revealed significantly greater uptake of (188)Re-liposomes linked to these peptides as compared with non-targeting (188)Re-liposomes. Conjugation with these peptides also significantly increased the therapeutic efficacy of Lipo-Dox. Notably, peptide-conjugated Lipo-Dox significantly reduced stem-cell subpopulation in xenografts of breast cancer. The structure-based optimization strategy for peptides described here may be useful for developing peptide drugs for cancer imaging and therapy.

Dengue virus (DENV) infection is currently at pandemic levels, with populations in tropical and subtropical regions at greatest risk of infection. Early diagnosis and management remain the cornerstone for good clinical outcomes, thus efficient and accurate diagnostic technology in the early stage of the disease is urgently needed. Serotype-specific monoclonal antibodies (mAbs) against the DENV1 nonstructural protein 1 (NS1), DA12-4, DA13-2, and DA15-3, which were recently generated using the hybridoma technique, are suitable for use in diagnostic platforms. Immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA) and Western blot analysis further confirmed the serotype specificity of these three monoclonal antibodies. The ELISA-based diagnostic platform was established using the combination of two highly sensitive mAbs (DA15-3 and DB20-6). The same combination was also used for the flow cytometry-based diagnostic platform. We report here the detection limits of flow cytometry-based and ELISA-based diagnostic platforms using these mAbs to be 0.1 and 1 ng/mL, respectively. The collected clinical patient serum samples were also assayed by these two serotyping diagnostic platforms. The sensitivity and specificity for detecting NS1 protein of DENV1 are 90% and 96%, respectively. The accuracy of our platform for testing clinical samples is more advanced than that of the two commercial NS1 diagnostic platforms. In conclusion, our platforms are suitable for the early detection of NS1 protein in DENV1 infected patients.

The objective of this study was to evaluate radiolabeled DOTA-SP90 as a radiotracer for breast cancer. The in vitro competition assay showed that radiolabeled DOTA-SP90 had significant binding affinity to BT-483 cancer cells. Biodistribution, nanoSPECT/CT and nanoPET/CT imaging results indicated that radiolabeled DOTA-SP90 can accumulate in tumors. In addition, radiolabeled DOTA-SP90 peptides can also detect metastatic tumors. Therefore, radiolabeled SP90 peptide may provide the potential capability as diagnostic agent for breast cancer patients.

Background EpCAM is a type I transmembrane glycoprotein with an extracellular domain (EpEX) and an intracellular domain (EpICD), which have 265 and 26 amino acid residues, respectively. EpCAM is highly expressed in advanced epithelial cancers and tumor-initiating cells, but its role in cancer progression remains to be elucidated. Methods To identify cell signaling pathways that are stimulated by EpEX, we used a Human Phospho-RTK Array Kit to screen for phosphorylation of RTKs. Inhibition of EpEX-induced EGFR-PI3K-AKT signaling was analyzed by small molecule inhibitors or shRNA knockdown. Results Here, we found that EpEX activated AKT signaling, thereby inducing the phosphorylation and nuclear exclusion of FOXO3a. The EGFR inhibitor, AG1478, and MEK inhibitor, U0126, both decreased the production of EpICD, which was found to be necessary for nuclear accumulation of β-catenin protein and expression of HIF1α target genes in vitro and in mouse xenograft models. We also demonstrated that treatment with an anti-EpCAM neutralizing antibody, EpAb2-6, decreased the ADAM17 and γ-secretase activity, the EpCAM-downstream gene expression, and tumor colony and sphere formation. We also found that EpAb2-6 inhibited EpEX-activated EGFR-PI3K-AKT signaling and induced apoptotic signaling through FOXO3a activation of HTRA2 gene expression. Importantly, we also showed that EpAb2-6 inhibited the nuclear translocation of EpICD and oncogenic signaling through β-catenin. Finally, in both metastatic and orthotopic animal models of colorectal cancer, EpAb2-6 therapy exhibited an antitumor effect and markedly extended the survival time of mice. Conclusions Our results demonstrate that EpEX contributes to malignancy by functioning as a growth factor, which activates EpICD-mediated signaling, thereby enhancing colon cancer cell survival. To the best of our knowledge, hEpAb2-6 is the first humanized anti-EpCAM antibody to directly trigger apoptosis in cancer cells. Thus, we provide novel insight into EpEX-EGFR signaling, which can be considered as a promising target for treatment of colon cancer. Legal entity responsible for the study The authors. Funding Academia Sinica. Disclosure All authors have declared no conflicts of interest.

Dengue fever is caused by four different serotypes of dengue virus (DENV) which is the leading cause of worldwide arboviral diseases in humans. Virus-like particles (VLPs) containing flavivirus prM/E proteins have been demonstrated to be a potential vaccine candidate; however, the structure of dengue VLP is poorly understood. Herein we show for the first time that mD2VLP particles possess a T=1 icosahedral symmetry with a groove located within the E-protein dimers near the 2-fold vertices that exposed highly overlapping, cryptic neutralizing epitopes through cryo-electron microscopy reconstruction. Mice vaccinated with highly matured virus-like particles derived from DENV serotype 2 (mD2VLP) can generate higher cross reactive (CR) neutralization antibodies (NtAbs) and were protected against all 4 serotypes of DENV through clonal expansion supported by hybridoma and B-cell repertoire analysis. Our results revealed that a “epitope-resurfaced” mature-form dengue VLP has the potential to induce quaternary structure-recognizing broad CR NtAbs.

Dengue fever is caused by four different serotypes of dengue virus (DENV) which is the leading cause of worldwide arboviral diseases in humans. The vaccine candidates under development require a tetravalent immunogen to induce a balanced immunity against all four serotypes of dengue virus. Herein we show that mice vaccinated with highly matured virus-like particles derived from DENV serotype 2 (mD2VLP) can generate higher and broader neutralization antibodies (NtAbs) against all 4 serotypes of DENV through clonal expansion supported by hybridoma and B-cell repertoire analysis. The cryo-electron microscopy reconstruction showed that mD2VLP particles possess a T=1 icosahedral symmetry with a groove located within the E-protein dimers near the 2-fold vertices that exposed highly overlapping, cryptic neutralizing epitopes. Most importantly, maternally transferred antibodies derived from mD2VLP-vaccinated female mice protected suckling mice from lethal challenge by all four serotypes of DENV. Our results support the fact that a universal dengue vaccine that protects against all four serotypes of dengue viruses can be achieved by using an immunogen such as mD2VLP.

Despite the low case fatality, Zika virus (ZIKV) infection has been associated with microcephaly in infants and Guillain-Barré syndrome. Antiviral and vaccine developments against ZIKV are still ongoing; therefore, in the meantime, preventing the disease transmission is critical. Primarily transmitted by Aedes species mosquitoes, ZIKV also can be sexually transmitted. We used AG129 mice lacking interferon-α/β and -γ receptors to study the testicular pathogenesis and sexual transmission of ZIKV. Infection of ZIKV progressively damaged mouse testes, increased testicular oxidative stress as indicated by the levels of reactive oxygen species, nitric oxide, glutathione peroxidase 4, spermatogenesis-associated-18 homolog in sperm and pro-inflammatory cytokines including IL-1β, IL-6, and G-CSF. We then evaluated the potential role of the antioxidant ebselen (EBS) in alleviating the testicular pathology with ZIKV infection. EBS treatment significantly reduced ZIKV-induced testicular oxidative stress, leucocyte infiltration and production of pro-inflammatory response. Furthermore, it improved testicular pathology and prevented the sexual transmission of ZIKV in a male-to-female mouse sperm transfer model. EBS is currently in clinical trials for various diseases. ZIKV infection could be on the list for potential use of EBS, for alleviating the testicular pathogenesis with ZIKV infection and preventing its sexual transmission., Author summary Male-to-female sexual transmission of ZIKV has been reported more than the other sexual modes. Here we observe the disease progression of ZIKV in the testicular tissue of mouse models by gaining access to interstitial cells, the basement membrane of seminiferous tubule, spermatogenic cells, and sperm. In addition, we develop an animal model to study male-to-female sexual transmission with a high transmissibility through seminal transfer that allows us to identify a possible therapeutic intervention. Our data indicate that testicular oxidative stress and pro-inflammatory response may contribute to testicular pathology as well as successful sexual transmission of ZIKV; thus, this could serve as a potential target for therapeutic purpose. We evaluated several potential antioxidants and found that ebselen (EBS) treatments in male mice display a better property to alleviate testicular pathogenesis and prevent seminal transmission of ZIKV than vitamin C or quercetin.

Nanocarriers, such as liposomes, have the potential to increase the payload of chemotherapeutic drugs while decreasing toxicity to non-target tissues; such advantageous properties can be further enhanced through surface conjugation of nanocarriers with targeting moieties. We previously reported that SP94 peptides, identified by phage display, exhibited higher binding affinity to human hepatocellular carcinoma (HCC) than to hepatocytes and other normal cells. Here, we confirm the tumor-targeting properties of SP94 peptide by near-infrared fluorescence imaging. Non-targeted PEGylated liposomal doxorubicin (LD) and SP94‑conjugated PEGylated liposomal doxorubicin (SP94‑LD) were compared by assessing pharmacokinetics, tissue distribution, and antitumor efficacy in xenograft-bearing mice, in order to investigate the effectiveness of SP94‑mediated targeting for cancer therapy. SP94‑LD demonstrated a significant increase in drug accumulation in tumors, while its plasma residence time was the same as its non-targeted equivalent. Consistent with this result, conjugation of targeting peptide SP94 enhances the therapeutic efficacy of liposomal doxorubicin in mouse models with hepatocellular carcinoma xenografts. Furthermore, combination targeted therapy exhibited a significant enhancement against orthotopic tumor growth, and markedly extended the survival of mice compared with all other treatments. Our study shows that SP94‑mediated targeting enhances antitumor efficacy by improving tumor pharmacokinetics and tissue distribution, allowing large amounts of antitumor drugs to accumulate in tumors.

Glutathione S-transferase mu 3 (GSTM3) is an enzyme involving in the detoxification of electrophilic compounds by conjugation with glutathione. Higher GSTM3 mRNA levels were reported in patients with ERα-positive breast cancer who received only tamoxifen therapy after surgery. Thus, this study aimed to clarify the oncogenic characteristics of GSTM3 in breast cancer and the mechanism of tamoxifen resistance. GSTM3 expression in human breast tumour tissues (n = 227) was analysed by RT-PCR and quantitative PCR. Western blot, promoter activity assays, and chromatin immunoprecipitation (ChIP) assays were used to investigate the mechanism of GSTM3 gene regulation. Hydrogen peroxide (H2O2)-induced cytotoxicity in breast cancer cells was detected by MTT assays and flow cytometry. The oncogenic characteristics of GSTM3 in MCF-7 cells were examined by siRNA knockdown in soft agar assays and a xenograft animal model. GSTM3 mRNA was highly expressed in ER- and HER2-positive breast cancers. Moreover, patients who received adjuvant Herceptin had increased GSTM3 mRNA levels in tumour tissue. Oestrogen-activated GSTM3 gene expression through ERα-mediated recruitment of SP1, EP300, and AP-1 complexes. GSTM3-silenced MCF-7 cells were more sensitive to H2O2, with significantly inhibited proliferation and colony formation abilities. Tamoxifen-resistant (Tam-R) cells lacking GSTM3 showed enhanced sensitivity to H2O2, but this result was contrary to that obtained after short-term tamoxifen exposure. The animal model suggested that GSTM3 silencing might suppress the tumourigenic ability of MCF-7 cells and increase tumour cell apoptosis. ROS production is one mechanism by which cancer drugs kill tumour cells, and according to our evidence, GSTM3 may play an important role in preventing breast cancer treatment-induced cellular cytotoxicity.

Thyroid hormone status has long been implicated in cancer development. Here we investigated the role of thyroxine (T4) in colorectal cancer cell lines HCT 116 (APC wild type) and HT-29 (APC mutant), as well as the primary cultures of cancer cells derived from patients. Cell proliferation was evaluated with standard assay and proliferation marker expression. β-Catenin activation was examined according to nuclear β-catenin accumulation and β-catenin target gene expression. The results showed that T4 increased colorectal cancer cell proliferation while cell number and viability were elevated by T4 in both established cell lines and primary cells. Moreover, the transcriptions of proliferative genes PCNA, CCND1, and c-Myc were enhanced by T4 in the primary cells. T4 induced nuclear β-catenin accumulation, as well as high cyclin D1 and c-Myc levels compared to the untreated cells. In addition, the β-catenin-directed transactivation of CCND1 and c-Myc promoters was also upregulated by T4. CTNNB1 transcription was raised by T4 in HCT 116, but not in HT-29, while the boosted β-catenin levels were observed in both. Lastly, the T4-mediated gene expression could be averted by the knockdown of β-catenin. These results suggested that T4 promotes β-catenin activation and cell proliferation in colorectal cancer, indicating that an applicable therapeutic strategy should be considered.

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 unknown whether progression of malignance can be directly inhibited by targeting EpCAM. Here, we have generated five novel monoclonal antibodies (mAbs) against EpCAM. One of these anti-EpCAM mAbs, EpAb2-6, was found to induce cancer cell apoptosis in vitro, inhibit tumor growth, and prolong the overall survival of both a pancreatic cancer metastatic mouse model and mice with human colon carcinoma xenografts. EpAb2-6 also increases the therapeutic efficacy of irinotecan, fluorouracil, and leucovorin (IFL) therapy in a colon cancer animal model and gemcitabine therapy in a pancreatic cancer animal model. Furthermore, EpAb2-6, which binds to positions Y95 and D96 of the EGF-II/TY domain of EpCAM, inhibits production of EpICD, thereby decreasing its translocation and subsequent signal activation. Collectively, our results indicate that the novel anti-EpCAM mAb can potentially be used for cancer-targeted therapy.

The purpose of this abstract was to assess the efficacy of peptide targeted chemotherapy for pancreatic carcinoma. Previously we have constructed four peptides that bind specifically to cancer cell lines, which were derived from three different carcinoma cell lines and their vascular endothelia: L-peptide: (L-P, anti-cancer cell membrane), RLLDTNRPLLPY; SP-94-P (anti-hepato-pancreatic cancer cell membrane), SFSHHTPILP; PC5-52-peptide (anti-tumor endothelia), SVSVGMKPSPRP; and control peptide, RLLDTNRGGGGG. These peptides were linked to pegylated liposomal iron oxide nanoparticles to identify the targeted tumor cells and vascular endothelia using MRI analysis, and were also linked to dextran coated liposomal doxorubicin (L-D) for treatment of non-obese diabetic, severe combined immunodeficiency (NOD-SCID) mice bearing pancreatic cancer cell (PANC-1) xenografts. Our results demonstrated that the tumor intensity of MRI is clearly decreased after SP-94-P-iron oxide was applied, and that in combination of application of L-P linked L-D (L-P-L-D) plus SP-94-P linked L-D (SP-94-P-L-D) and PC5-52-P linked L-D (PC5-52-P-L-D), they could inhibit pancreatic tumor growth with very mild adverse events. The use of the control peptide linked L-D also led to a decrease of the xenograft size, but also induced marked apoptotic change of their visceral organs. It is concluded that the combination of L-P-L-D, SP-94-P-L-D and PC5-52-P-L-D to treat pancreatic cancer xenograft in NOD SCID mice can clearly inhibit pancreatic cancer growth with minimal adverse events. Citation Format: Chin-Tarng Lin, Chen-Der Wu, Jen-Chieh Lee, Han-Chung Wu, Chung-Wei Lee, Chin-Feng Lin, Ming-Chieh Hsu. Peptide-targeted chemotherapy for pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3880.

We present the enhancement of targeted treatment on colon cancer cell via microscopic imaging ellipsometry (MIE). All spectroscopic MIE signals on 5μm×5μm area in visible range are captured within the modified Optrel MULTISKOP system. Colon cancer cells are cultured in Bottom-up Millicell EZ SLIDE 4-well structure under the environment (37°C, 10% CO 2 ). Original single colon cancer cell, single colon cancer cell under untargeted-treatment, and single colon cancer cell under targeted-treatment are studied by specular-reflective mode and off-specular scattering mode in this experiment. Some polarization-related and phase-related MIE images are analyzed to reveal the improvement of targeted-treatment by observing changes in specular and off-specular reflectance and absorption.

The anti-cancer efficacy of TNF-related apoptosis-inducing ligand (TRAIL)-based therapy is limited due to systemic toxicity, poor bioavailability, and the development of TRAIL-resistance. We developed a tumor-targeted LCPP (Lipid/Calcium/Phosphate/Protamine) nanoparticle (NP) to deliver TRAIL plasmid DNA (pDNA) into hepatocellular carcinoma (HCC) cells. TRAIL pDNA was encapsulated in a pH stimuli-responsive calcium phosphate (CaP) core, and protamine was added to facilitate nuclear delivery of pDNA. In addition, the intracellular release of Ca2+ from the CaP core overcame TRAIL resistance via calcium influx-dependent DR5 upregulation. TRAIL expression also attenuated fibrosis in the liver tissues surrounding HCCs by reverting activated hepatic stellate cells (HSCs) to a quiescent state or by directly inducing apoptosis in activated HSCs. Conclusion: TRAIL pDNA delivered by HCC-targeted LCPP NPs in combination with conventional sorafenib treatment attenuated HCC progression as well as liver fibrosis. Overall, our study presents an effective TRAIL-based cancer therapy that could be developed for clinical applications. This article is protected by copyright. All rights reserved.

Here, two types of cellulose-based in vitro diagnostic devices are demonstrated for the diagnosis of dengue virus infection in both buffer system and human serum: 1) paper-based ELISA for providing the semiquantitative information of the disease activity of serotype-2 dengue fever to healthcare persons (i.e., monitoring the disease activity with a specific serotype in single patients); 2) lateral flow immunoassays to screen for infection with serotype-2 dengue fever (i.e., rapid YES or NO diagnosis prepared for large populations, in terms of global public health). Paper-based ELISA (specific to serotype-2 dengue fever), which builds off of our previous studies and a revised previous ELISA procedure, owns multiple advantages: 1) high sensitivity (about 40 times higher than the current ELISA-based approaches, due to our therapeutic-based monoclonal antibody) and specificity (specific to dengue virus serotype-2 nonstructural protein-1 antigens); 2) tiny amount of sample and reagent used for single tests; 3) short operating duration (i.e., rapid diagnostic device); and, 4) inexpensiveness (appropriate for use in all developing and underdeveloped nations of the world). Due to the higher sensitivity and shorter operating duration of paper-based ELISA (compared with conventional ELISA, and lateral flow immunoassays also performed in this study), this study has not only been able to perform the diagnosis of dengue virus serotype-2 nonstructural protein-1 antigens in both buffer system and human serum but also to evaluate dengue virus serotype-2 envelope proteins in the buffer system, thus successfully achieving the first such use of these proteins as the target antigen for the development of diagnostic tools. These results provide a more comprehensive understanding for the genesis of dengue fever diagnostic tools (through antibody-antigen recognition).

Pancreatic adenocarcinoma is an aggressive disease with a high mortality rate. In this study, we have newly generated a monoclonal antibody (mAb), Pa65-2, which specifically binds to pancreatic cancer cells and tumor blood vessels. The target protein of Pa65-2 is identified as human clathrin heavy chain (CHC). In vitro and In vivo study showed that suppression of CHC either by shRNA or by Pa65-2 inhibited tumor growth and angiogenesis. One of the key functions of CHC was to bind with the hypoxia-inducing factor (HIF)-1α protein, increasing the stability of this protein and facilitating its nuclear translocation, thereby regulating the expression of VEGF. Taken together, our findings indicate that CHC plays a role in the processes of tumorigenesis and angiogenesis. Pa65-2 antibody or CHC shRNA can potentially be used for pancreatic cancer therapy.

Epithelial cell adhesion molecule (EpCAM) is highly expressed in advanced epithelial cancers and tumor-initiated cells (TICs), but its roles in cancer progression remain to be elucidated. Here, we showed that the extracellular domain of EpCAM (EpEX) could bind to EGFR through EGF-like domain I, and subsequently activated its downstream molecules, ERK1/2 and Akt. EGFR inhibitor and knockdown of EGFR by shRNA ablated EpEX-induced ERK1/2 phosphorylation. Regulated intramembrane proteolysis (RIP) of EpCAM was induced similarly by EpEX and EGF through EGFR-dependent activation of ERK pathway. MEK inhibitor, U0126, could abolish ADAM17 and PS2 phosphorylation induced by EpEX. EpAb2-6, an anti-EpEX neutralizing monoclonal antibody, inhibits EpEX-activated EGFR-PI3K-AKT pathway in detached colon cancer cells. Moreover, intracellular domain of EpCAM (EpICD), the product of RIP-induced cleavage of EpCAM, is necessary for nuclear accumulation of β-catenin, and their target gene expressions in vitro and in mouse xenograft models. We also found that an increase of nuclear EpICD observed in CRCs predicted metastasis and poor prognosis in CRC patients. Finally, in animal model studies, EpAb2-6 therapy exhibited an enhanced antitumor effect and markedly extended the survival time of mice with human colorectal cancer in metastatic and orthotopic models. These results demonstrate that EpEX works as a growth factor in activating EGFR-mediated signaling, and as a potential target for treatment of colon cancer. This research was supported by grants from Academia Sinica and Ministry of Science and Technology [MOST 104-0210-01-09-02,MOST 105-0210-01-13-01], and the National Science Council (NSC103-2321-B-001-064), Taiwan (to H-C Wu). Citation Format: Kang-Hao Liang, Jun-Kai Lai, I-I Kuan, Hsien-Cheng Tso, Han-Chung Wu. EpCAM/EpEX regulate tumor progression through EGFR signaling in colon cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 327. doi:10.1158/1538-7445.AM2017-327

Backgrounds: Being a crucial hormone regulating growth, metabolism and various physiological processes, the status of thyroid hormone has long been implicated in cancer risks and tumor developments. In the present study, we aimed to look at the role of thyroid hormone, thyroxine (T4), in colorectal cancer cell proliferation and β-catenin activation, which is highly involved in both normal and oncogenic developments of the gut. Materials and Methods: The effects of T4 in colorectal cancer cell lines HCT 116 (APC wild type) and HT-29 (APC mutant) as well as the primary cells derived from colorectal cancer patients were studied. Cell proliferation was evaluated according to cell counting, MTT assay and qRT-PCR. The activation of β-catenin was examined using Western blotting, qRT-PCR and immunoprecipitation. Results: The results showed that T4 increased the cell number of both HCT 116 and HT-29 cells compared to the untreated cells. In both cell lines, T4 induced nuclear β-catenin accumulation and the protein levels of WNT/β-catenin targets Cyclin D1 and c-Myc. The mRNA expression of CTNNB1 was elevated by T4 in HCT 116 cells, but not in HT-29 cells. In APC wild type HCT 116 cells, T4 increased the WNT4 mRNA expression and decreased the association between β-catenin and the WNT-regulated β-catenin destruction complex. Moreover, the cell numbers of T4-treated primary cells were higher compared to the untreated cells while the mRNA expressions of proliferative genes PCNA, CCND1 and c-Myc were elevated by T4. In the primary cells, T4-induced nuclear β-catenin accumulation, protein levels of Cyclin D1 and c-Myc, and mRNA expressions of CTNNB1 and WNT4 were also observed. Conclusions: T4 promoted cell proliferation and β-catenin activation in colorectal cancer. In the cells with different APC mutation status, the activation of β-catenin was regulated by different mechanisms. Citation Format: Yee-Shin Lee, Meng-Ti Hsieh, Yu-Tang Chin, Aleck Hercbergs, Paul J. Davis, Han-Chung Wu, Hung-Yun Lin. Thyroid hormone, thyroxine, promotes cell proliferation and β-catenin activation in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3625. doi:10.1158/1538-7445.AM2017-3625

Due to the development of drug resistance, the outcome for the majority of patients with acute myeloid leukemia (acute myelogenous leukemia; AML) remains poor. To prevent drug resistance and increase the therapeutic efficacy of treating AML, the development of new combinatory drug therapies is necessary. Sonic hedgehog (Shh) is expressed in AML biopsies and is essential for the drug resistance of cancer stem cells of AML. AML patients are frequently infected by bacteria and exposed to lipopolysaccharide (LPS). LPS itself, its derivatives, and its downstream effectors, such as tumor necrosis factor-α (TNF-α) and interferons (IFNs), have been shown to provoke anti-tumor effects. The application of a Shh inhibitor against AML cells in the presence of LPS/TNF-α/IFNs has not been investigated. We found that the Shh inhibitor cyclopamine in combination with LPS treatment synergistically induced massive cell apoptosis in THP-1 and U937 cells. The cytotoxic effects of this combined drug treatment were confirmed in 5 additional AML cell lines, in primary AML cells, and in an AML mouse model. Replacing cyclopamine with another Shh inhibitor, Sant-1, had the same effect. LPS could be substituted by TNF-α or IFNs to induce AML cell death in combination with cyclopamine. Our results suggest a potential strategy for the development of new therapies employing Shh antagonists in the presence of LPS/TNF-α/IFNs for the treatment of AML patients.

The purpose of this study was to analyze the encapsulation of superparamagnetic iron oxide nanoparticles (SPION) by the lipid nanoparticle conjugated with the 12-mer peptides (RLLDTNRPLLPY, L-peptide), and the delivery of this complex into living cells. The lipid nanoparticles employed in this work were highly hydrophilic, stable, and contained poly(ethylene-glycol) for conjugation to the bioactive L-peptide. The particle sizes of two different magnetic lipid nanoparticles, L-peptide modified (LML) and non-L-peptide modified (ML), were both around 170 nm with a narrow range of size disparity. The transversal relaxivity, r2, for both LML and ML nanoparticles were found to be significantly higher than the longitudinal relaxivity r1 (r2/r1 > 20). The in vitro tumor cell targeting efficacy of the LML nanoparticles were evaluated and compared to the ML nanoparticles, upon observing cellular uptake of magnetic lipid nanoparticles by the nasopharyngeal carcinoma cells, which express cell surface specific protein for the L-peptide binding revealed. In the Prussian blue staining experiment, cells incubated with LML nanoparticles indicated much higher intracellular iron density than cells incubated with only the ML and SPION nanoparticles. In addition, the MTT assay showed the negligible cell cytotoxicity for LML, ML and SPION nanoparticles. The MR imaging studies demonstrate the better T2-weighted images for the LML-nanoparticle-loaded nasopharyngeal carcinoma cells than the ML- and SPION-loaded cells.

Building on the initial successful optimization of a novel series of tetraindoles, a second generation of the compounds with changes in the core phenyl ring was synthesized to improve anticancer properties. 17 new compounds with different rigidity, planarity, symmetry and degree of conjugation of their core structures to 5-hydroxyindole units were synthesized. All the compounds were fully characterized and tested against breast cancer cell line (MDA-MB-231). The results revealed that the core structure is required for activity and it should be aromatic, rigid, planar, symmetrical and conjugated for optimal activity. Compound 29, which has strong anticancer activity against various tumor-derived cell lines, including Mahlavu (hepatocellular), SK-HEP-1 (hepatic), HCT116 (colon), MIA PaCa-2 (pancreatic), H441 (lung papillary), A549 (lung), H460 (non-small cell lung) and CL1-5 (lung carcinoma) with IC50 values ranging from 0.19 to 3.50μM, was generated after series of successive optimizations. It was found to induce cell cycle arrest and apoptosis in vitro and inhibit tumor growth in the non-obese diabetic-severe combined immunodeficiency (NOD/SCID) mice bearing xenografted MIA PaCa-2 human pancreatic cancer.

Solid tumors are known to recruit new blood vessels to support their growth. Therefore, unique molecules expressed on tumor endothelial cells can function as targets for the antiangiogenic therapy of cancer. Current efforts are focusing on developing therapeutic agents capable of specifically targeting cancer cells and tumor-associated microenvironments including tumor blood vessels. These therapies hold the promise of high efficacy and low toxicity. One recognized strategy for improving the therapeutic effectiveness of conventional chemotherapeutics is to encapsulate anticancer drugs into targeting liposomes that bind to the cell surface receptors expressed on tumor-associated endothelial cells. These anti-angiogenic drug delivery systems could be used to target both tumor blood vessels as well as the tumor cells, themselves. This article reviews the mechanisms and advantages of various present and potential methods using peptide-conjugated liposomes to specifically destroy tumor blood vessels in anticancer therapy.

It is known that solid tumors recruit new blood vessels to support tumor growth, but the molecular diversity of receptors in tumor angiogenic vessels might also be used clinically to develop better targeted therapy. In vivo phage display was used to identify peptides that specifically target tumor blood vessels. Several novel peptides were identified as being able to recognize tumor vasculature but not normal blood vessels in severe combined immunodeficiency (SCID) mice bearing human tumors. These tumor-homing peptides also bound to blood vessels in surgical specimens of various human cancers. The peptide-linked liposomes containing fluorescent substance were capable of translocating across the plasma membrane through endocytosis. With the conjugation of peptides and liposomal doxorubicin, the targeted drug delivery systems enhanced the therapeutic efficacy of the chemotherapeutic agent against human cancer xenografts by decreasing tumor angiogenesis and increasing cancer cell apoptosis. Furthermore, the peptide-mediated targeting liposomes improved the pharmacokinetics and pharmacodynamics of the drug they delivered compared with nontargeting liposomes or free drugs. Our results indicate that the tumor-homing peptides can be used specifically target tumor vasculature and have the potential to improve the systemic treatment of patients with solid tumors.

Hepatocellular carcinoma is the fourth leading cause of cancer death worldwide. Novel treatment strategies derived from increased knowledge of molecular oncology are constantly being developed to cure this disease. Here, we used phage display to identify a novel peptide (SP94), which binds specifically to hepatocellular carcinoma cells. In vitro, the phage clone PC94 was shown to bind to hepatocellular carcinoma cell lines by ELISA and flow cytometry analysis. In vivo, PC94 homed specifically to tumor tissues but not to normal visceral organs in severe combined immunodeficient mice bearing human hepatocellular carcinoma xenografts. This homing ability could be competitively inhibited by synthetic peptide, SP94. Immunohistochemical staining confirmed that PC94 localized to tumor tissues and that it could not be detected in SP94-competed tumor tissues. In addition, PC94 recognized the tumor tissue but not nontumor tissue in surgical specimens from hepatocellular carcinoma patients, with a positive rate of 61.3% (19 of 31). With the conjugation of SP94 and liposomal doxorubicin, the targeted drug delivery system enhanced the therapeutic efficacy against hepatocellular carcinoma xenografts through enhanced tumor apoptosis and decreased tumor angiogenesis. Our results indicate that SP94 has the potential to improve the systemic treatment of patients with advanced hepatocellular carcinoma. [Mol Cancer Ther 2008;7(3):579–89]

Colorectal cancer is one of the most commonly diagnosed cancers and a leading cause of cancer mortality worldwide. Current treatment for colorectal cancer results in only limited success, and more effective therapeutic approaches are thus urgently needed. The development of new methods for early detection and effective treatments for cancer is contingent on the identification of biomarkers on the surface of cancer cells, as well as isolation of tumor-specific ligands with high binding affinity to such biomarkers. In vitro biopanning of a phage-displayed peptide library was used to identify specific peptides binding to human colorectal carcinoma cells. The targeting peptide pHCT74 showed the greatest potential for drug delivery in both in vitro and in vivo studies. The use of biotinylated peptides combined with an affinity trapping method and liquid chromatography-tandem mass spectrometry identified the target protein for the pHCT74 peptide as α-enolase. In animal model studies, combined pHCT74-conjugated liposomal doxorubicin (pHCT74-LD) and pHCT74-conjugated liposomal vinorelbine (pHCT74-sLV) therapy exhibited an enhanced antitumor effect and markedly extended the survival of mice with human colorectal cancer in subcutaneous and orthotopic models. Our findings indicate that α-enolase-targeted lipid nanoparticles have great potential for application in targeted drug delivery systems for colorectal cancer therapy.

The four serotypes of dengue virus (DENV1-4) pose a serious threat to global health. Cross-reactive and non-neutralizing antibodies enhance viral infection, thereby exacerbating the disease via antibody-dependent enhancement (ADE). Studying the epitopes targeted by these enhancing antibodies would improve the immune responses against DENV infection. In order to investigate the roles of antibodies in the pathogenesis of dengue, we generated a panel of 16 new monoclonal antibodies (mAbs) against DENV4. Using plaque reduction neutralization test (PRNT), we examined the neutralizing activity of these mAbs. Furthermore, we used the in vitro and in vivo ADE assay to evaluate the enhancement of DENV infection by mAbs. The results indicate that the cross-reactive and poorly neutralizing mAbs, DD11-4 and DD18-5, strongly enhance DENV1-4 infection of K562 cells and increase mortality in AG129 mice. The epitope residues of these enhancing mAbs were identified using virus-like particle (VLP) mutants. W212 and E26 are the epitope residues of DD11-4 and DD18-5, respectively. In conclusion, we generated and characterized 16 new mAbs against DENV4. DD11-4 and D18-5 possessed non-neutralizing activities and enhanced viral infection. Moreover, we identified the epitope residues of enhancing mAbs on envelope protein. These results may provide useful information for development of safe dengue vaccine.

We have generated a novel monoclonal antibody (mAb), OCAb9-1, which specifically binds to various types of cancer cell lines, but not to normal cells. According to the results of immunoaffinity chromatography, LC-MS/MS analysis, co-immunoprecipitation, and RNA interference studies, the target protein of OCAb9-1 is the epithelial cell adhesion molecule (EpCAM). EpCAM is a type I transmembrane glycoprotein which is highly expressed in epithelial-transformed neoplasia and tumor-initiating cells (TICs). However, regulation of EpCAM gene expression in tumors and its role in tumorigenesis are not fully understood. In the present study, we show that EpCAM expression is elevated in several cancer cell lines and tumor tissues. Loss-of-function experiments were performed to demonstrate that EpCAM negatively regulates expression of p53 and p21, and promotes tumor cell growth, colony formation, migration and invasion. The median overall survival of tumor-bearing mice treated with OCAb9-1 was significantly higher than that of PBS-treated mice. Moreover, we report that the interplay between SUZ12 and JMJD3 results in dynamic regulation of lysine 27 trimethylation of histone 3 (H3K27me3). Taken together, our findings suggest that the anti-EpCAM mAb may be suitable for use in cancer diagnosis, prognosis, imaging and therapy. Furthermore, EpCAM overexpression in cancer cells is strongly associated with tumor progression, and may be regulated by epigenetic mechanisms.

Currently, epithelial ovarian cancer is viewed as a heterogeneous disease with five major histological subtypes. Clear cell carcinoma represents a specific histological subtype of epithelial ovarian cancer that demonstrates more aggressive clinical behavior and drug resistance compared with other subtypes. Nevertheless, clear cell carcinoma is treated in the same manner as the other subtypes without any particular consideration to its unique clinical characteristics. To improve the therapeutic efficacy of the current liposomal doxorubicin approach for the treatment of clear cell carcinoma, we aimed to develop a novel peptide-conjugated liposomal doxorubicin to actively target this subtype. Two phage clones (OC-6 and OC-26) that specifically bound to clear cell carcinoma were isolated from a phage peptide display library after biopanning procedures. The peptide sequences were translated and aligned (OCSP-6 for OC-6, and OCSP-26 for OC-26, respectively). Peptide-conjugated nanoparticles demonstrated better tumor endocytosis and time-dependent gradual increase of intracellular drug uptake than non-targeting liposomal nanoparticles. Furthermore, peptide-conjugated liposomal doxorubicin better controlled tumors than did non-targeting liposomal doxorubicin. The current work may pave a new way for the development of drugs that target each subtype of epithelial ovarian cancer in the future.

The mechanism of action, leakage of cytochrome c from mitochondria into cytosol, for the antineoplastic compound glyfoline was examined. Additionally, our current studies revealed that glyfoline induced apoptotic changes and arrested cell cycle procession at the G2/M phase in nasopharyngeal carcinoma (NPC). A reverse transcriptase polymerase chain reaction (RT-PCR) showed no specific changes of apoptosis-related gene expression (i. e., bax, ICE-alpha,beta, bcl-2, and c-myc). However, no similar changes were detected in fibroblasts and peripheral lymphocytes after glyfoline treatment suggesting that glyfoline has a higher affinity for tumor cells than for normal cells.

To understand whether the p53-regulated mdm2 gene expression was altered by the Epstein-Barr virus (EBV) in nasopharyngeal carcinoma (NPC), the NPC-TW01 cell line was infected by EBV through IgA receptor-mediated endocytosis. The mdm2 gene was expressed only in a small fraction of the NPC cell population and could be enhanced in the EBV-infected (EBV+) cells. In the animals bearing EBV+ and EBV- NPC xenografts, the MDM2+ cells only appeared in clusters in both EBV+ and EBV- tumors with stronger expression in EBV+ cells. Cotransfection of pmdm2-Luc plus pSV40-p53 plus pCMV-LMP1 in the NPC-TW06 line that had p53 heterozygous point mutation showed stronger mdm2 promoter activity than cells cotransfected with pmdm2-Luc plus pSV40-p53, but no mdm2 promoter activity was seen in cells cotransfected with pmdm2-Luc plus pCMV-LMP1. Only the EBV-LMP1 but not the EBV-LMP2A gene could enhance p53 to upregulated mdm2 expression. Tumor cells in NPC biopsy specimens revealed similar mdm2 expression as in the animal model. It is concluded that although EBV can indirectly enhance mdm2 gene expression in tumor cells that express this gene, it cannot turn on or directly regulate mdm2 expression in cells that do not express this gene. In other words, EBV plays a role as an enhancer in NPC tumorigenesis.

Severe acute respiratory syndrome (SARS) has emerged as a highly contagious, sometimes fatal disease. To find disease-specific B cell epitopes, phage-displayed random peptide libraries were panned on serum immunoglobulin (Ig) G antibodies from patients with SARS. Forty-nine immunopositive phage clones that bound specifically to serum from patients with SARS were selected. These phageborne peptides had 4 consensus motifs, of which 2 corresponded to amino acid sequences reported for SARS-associated coronavirus (SARSCoV). Synthetic peptide binding and competitive-inhibition assays further confirmed that patients with SARS generated antibodies against SARS-CoV. Immunopositive phage clones and epitope-based peptide antigens demonstrated clinical diagnostic potential by reacting with serum from patients with SARS. Antibody-response kinetics were evaluated in 4 patients with SARS, and production of IgM, IgG, and IgA were documented as part of the immune response. In conclusion, B cell epitopes of SARS corresponded to novel coronavirus. Our epitope-based serologic test may be useful in laboratory detection of the virus and in further study of the pathogenesis of SARS.

Studies of the pathogenesis of dengue hemorrhagic fever (DHF), a potentially life-threatening disease, have revealed the importance of initial high levels of virus replication. However, the possible involvement of virus during the transition from fever to defervescence, a critical stage in determining the severity of disease, has not been appreciated. Using quantitative reverse transcription-polymerase chain reaction, we examined the levels of plasma dengue viral load during both fever and defervescence periods in patients from a DEN-3 outbreak in southern Taiwan in 1998. Higher levels of plasma dengue viral RNA were found in DHF patients than in DF patients. During defervescence, while the level of plasma dengue viral RNA was undetectable in most DF patients, it remains high in all DHF patients. Using a modified immunoprecipitation assay, we demonstrated for the first time that the plasma dengue viruses persisting during defervescence were in the immune complexes for most DHF patients. These findings suggest that continued active viral replication or delay in the clearance of viremia contributes to the pathogenesis of DHF. Moreover, high levels of plasma dengue viral RNA during defervescence may serve as a disease marker for DHF.

Metastatic disease is the leading cause of cancer mortality. Identifying biomarkers and regulatory mechanisms is important toward developing diagnostic and therapeutic tools against metastatic cancer. In this study, we demonstrated that podocalyxin-like 1 (PODXL) is overexpressed in breast tumor cells and increased in lymph node metastatic cancer. Mechanistically, we found that the expression of PODXL was associated with cell motility and invasiveness. Suppression of PODXL in MDA-MB-231 cells reduced lamellipodia formation and focal adhesion kinase (FAK) and paxillin phosphorylation. PODXL knockdown reduced the formation of invadopodia, such as inhibiting the colocalization of F-actin with cortactin and suppressing phosphorylation of cortactin and neural Wiskott-Aldrich syndrome protein. Conversely, overexpression of PODXL in MCF7 cells induced F-actin/cortactin colocalization and enhanced invadopodia formation and activation. Invadopodia activity and tumor invasion in PODXL-knockdown cells are similar to that in cortactin-knockdown cells. We further found that the DTHL motif in PODXL is crucial for regulating cortactin phosphorylation and Rac1/Cdc42 activation. Inhibition of Rac1/Cdc42 impeded PODXL-mediated cortactin activation and FAK and paxillin phosphorylation. Moreover, inhibition of PODXL in MDA-MB-231 cells significantly suppressed tumor colonization in the lungs and distant metastases, similar to those in cortactin-knockdown cells. These findings show that overexpression of PODXL enhanced invadopodia formation and tumor metastasis by inducing Rac1/Cdc42/cortactin signaling network.

Many nasopharyngeal carcinoma (NPC) biopsy specimens contain Epstein-Barr virus (EBV). However, the response of NPC cells to EBV infection in vitro and in vivo is not well characterized. In this experiment we infected NPC cells with EBV particles through endocytosis of a complex of EBV immunoglobulin A (IgA) secretory component (SC) protein to observe the response of host cells to the foreign viral infection in vitro. We found that EBV particles were endocytosed and stabilized in NPC nuclei 24 hours after infection; the EBV genomes were then gradually decreased after serial passages within 3 to 4 weeks by the following pathway: the EBV genomes first moved toward the nuclear envelope from the center of the nucleus; after crossing the nuclear envelope, they moved into the cytoplasm and toward the plasma membrane and were discharged by exocytosis. At the 10th day of EBV infection, EBV-latent membrane protein-1 and Epstein-Barr nuclear antigen (EBNA)-1 protein expressions could be detected, but not EBV-viral capsid antigen. Observation of EBNA-1 protein and host growth factor and cytokine gene expressions in the weeks after incubation revealed that the EBNA-1 protein expression was decreased proportionally with decrease of EBV genome. The mRNA expression of epithelial growth factor receptor, transforming growth factor (TGF)-alpha, interleukin (IL)-1beta, IL-6, and granulocyte-macrophage colony-stimulating factor increased within 1 to 2 weeks after infection, and gradually recovered to the original level at 3 to 4 weeks, whereas the mRNAs of TGFbeta1, TGFbeta receptor type I (TGFbetaRI), TGFbetaR type II, IL-8, and tumor necrosis factor-alpha remained unchanged. It is concluded that in vitro EBV infection in NPC cells results in increase of certain growth factor and cytokine gene expressions in host cells. The change in gene expression returns to the original level approximately 3 to 4 weeks after infection because of exocytosis of EBV DNA by the infected cells through an unidentified mechanism.

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

A T60M mutation in the thiazide-sensitive sodium chloride cotransporter (NCC) is common in patients with Gitelman's syndrome (GS). This mutation prevents Ste20-related proline and alanine-rich kinase (SPAK)/oxidative stress responsive kinase-1 (OSR1)-mediated phosphorylation of NCC and alters NCC transporter activity in vitro. Here, we examined the physiologic effects of NCC phosphorylation in vivo using a novel Ncc T58M (human T60M) knock-in mouse model. Ncc(T58M/T58M) mice exhibited typical features of GS with a blunted response to thiazide diuretics. Despite expressing normal levels of Ncc mRNA, these mice had lower levels of total Ncc and p-Ncc protein that did not change with a low-salt diet that increased p-Spak. In contrast to wild-type Ncc, which localized to the apical membrane of distal convoluted tubule cells, T58M Ncc localized primarily to the cytosolic region and caused an increase in late distal convoluted tubule volume. In MDCK cells, exogenous expression of phosphorylation-defective NCC mutants reduced total protein expression levels and membrane stability. Furthermore, our analysis found diminished total urine NCC excretion in a cohort of GS patients with homozygous NCC T60M mutations. When Wnk4(D561A/+) mice, a model of pseudohypoaldosteronism type II expressing an activated Spak/Osr1-Ncc, were crossed with Ncc(T58M/T58M) mice, total Ncc and p-Ncc protein levels decreased and the GS phenotype persisted over the hypertensive phenotype. Overall, these data suggest that SPAK-mediated phosphorylation of NCC at T60 regulates NCC stability and function, and defective phosphorylation at this residue corrects the phenotype of pseudohypoaldosteronism type II.

Targeted delivery of drugs to tumors represents a significant advance in cancer diagnosis and therapy. Therefore, development of novel tumor-specific ligands or pharmaceutical nanocarriers is highly desirable. In this study, we utilized phage display to identify a new targeting peptide, SP90, which specifically binds to breast cancer cells, and recognizes tumor tissues from breast cancer patients. We used confocal and electron microscopy to reveal that conjugation of SP90 with liposomes enables efficient delivery of drugs into cancer cells through endocytosis. Furthermore, in vivo fluorescent imaging demonstrated that SP90-conjugated quantum dots possess tumor-targeting properties. In tumor xenograft and orthotopic models, SP90-conjugated liposomal doxorubicin was found to improve the therapeutic index of the chemotherapeutic drug by selectively increasing its accumulation in tumors. We conclude that the targeting peptide SP90 has significant potential in improving the clinical benefits of chemotherapy in the treatment and the diagnosis of breast cancer.