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author:("Qiao, cinxia")
1.  Anti-IGF-1R monoclonal antibody inhibits the carcinogenicity activity of acquired trastuzumab-resistant SKOV3 
Background
Antibody resistance, not only de novo but also acquired cases, usually exists and is related with lower survival rate and high risk of recurrence. Reversing the resistance often results in better clinical therapeutic effect. Previously, we established a trastuzumab-resistant ovarian cancer cell line, named as SKOV3-T, with lower HER2 and induced higher IGF-1R expression level to keep cell survival.
Methods
IGF-1R was identified important for SKOV3-T growth. Then, a novel anti-IGF-1R monoclonal antibody, named as LMAb1, was used to inhibit SKOV3-T in cell growth/proliferation, migration, clone formation and in vivo carcinogenicity.
Results
In both in vitro and in vivo assays, LMAb1 showed effective anti-tumor function, especially when being used in combination with trastuzumab, which was beneficial to longer survival time of mice as well as smaller tumor. It was also confirmed preliminarily that the mechanism of antibody might be to inhibit the activation of IGF-1R and downstream MAPK, AKT pathway transduction.
Conclusion
We achieved satisfactory anti-tumor activity using trastuzumab plus LMAb1 in trastuzumab-resistant ovarian cancer model. In similar cases, not only acquired but also de novo, good curative effect might be achieved using combined antibody therapy strategies.
doi:10.1186/s13048-014-0103-5
PMCID: PMC4260252  PMID: 25424625
IGF-1R; Monoclonal antibody; Acquired resistant; Trastuzumab; Ovarian cancer
2.  Potent anti-angiogenesis and anti-tumor activity of a novel human anti-VEGF antibody, MIL60 
Cellular and Molecular Immunology  2014;11(3):285-293.
Angiogenesis is crucial for tumor development, growth and metastasis. Vascular endothelial growth factor (VEGF) has been implicated in promoting solid tumor growth and metastasis via stimulating tumor-associated angiogenesis, and blocking the activity of VEGF can starve tumors. Avastin, which is a humanized anti-VEGF antibody, has been successfully applied in clinics since 2004. However, the price of Avastin is extremely high for Chinese people. Here, we report a novel human anti-VEGF neutralizing antibody, MIL60, which shows an affinity comparable to that of Avastin (the KD value of MIL60 was 44.5 pM, while that of Avastin was 42.7 pM). MIL60 displays favorable actions in inhibiting VEGF-triggered endothelial cell proliferation (the IC50 value of MIL60 was 31±6.4 ng/ml and that of Avastin was 47±8.1 ng/ml), migration (8 µg/ml or 0.8 µg/ml MIL60 versus the control: P<0.05) and tube formation (2 µg/ml or 0.2 µg/ml MIL60 versus the control: P<0.05) via the VEGFR2 signaling pathway. Moreover, MIL60 was shown to inhibit tumor growth and angiogenesis in vivo in xenograft models of human colon carcinoma and ovarian cancer using immunotherapy and immunohistochemistry analysis (MIL60 versus N.S.: P=0.0007; Avastin versus N.S.: P=0.00046). These data suggest that MIL60 is a potential therapeutic, anti-angiogenic agent. Our work provides a novel anti-VEGF antibody, which can be considered an anti-tumor antibody candidate and a new option for patients with various cancers.
doi:10.1038/cmi.2014.6
PMCID: PMC4085495  PMID: 24608894
angiogenesis; anti-VEGF antibody; cancer
3.  Structural basis of LaDR5, a novel agonistic anti-death receptor 5 (DR5) monoclonal antibody, to inhibit DR5/TRAIL complex formation 
BMC Immunology  2012;13:40.
Background
As a member of the TNF superfamily, TRAIL could induce human tumor cell apoptosis through its cognate death receptors DR4 or DR5, which can induce formation of the death inducing signaling complex (DISC) and activation of the membrane proximal caspases (caspase-8 or caspase-10) and mitochondrial pathway. Some monoclonal antibodies against DR4 or DR5 have been reported to have anti-tumor activity.
Results
In this study, we reported a novel mouse anti-human DR5 monoclonal antibody, named as LaDR5, which could compete with TRAIL to bind DR5 and induce the apoptosis of Jurkat cells in the absence of second cross-linking in vitro. Using computer-guided molecular modeling method, the 3-D structure of LaDR5 Fv fragment was constructed. According to the crystal structure of DR5, the 3-D complex structure of DR5 and LaDR5 was modeled using molecular docking method. Based on distance geometry method and intermolecular hydrogen bonding analysis, the key functional domain in DR5 was predicted and the DR5 mutants were designed. And then, three mutants of DR5 was expressed in prokaryotic system and purified by affinity chromatograph to determine the epitope of DR5 identified by LaDR5, which was consistent with the theoretical results of computer-aided analysis.
Conclusions
Our results demonstrated the specific epitope located in DR5 that plays a crucial role in antibody binding and even antineoplastic bioactivity. Meanwhile, revealed structural features of DR5 may be important to design or screen novel drugs agonist DR5.
doi:10.1186/1471-2172-13-40
PMCID: PMC3436762  PMID: 22788777
TRAIL; Death receptor 5; Monoclonal antibody; Apoptosis; Breast cancer
4.  Arg9 facilitates the translocation and downstream signal inhibition of an anti-HER2 single chain antibody 
BMC Research Notes  2012;5:336.
Background
HER2 plays a critical role in the pathogenesis of many cancers and is linked to poor prognosis or cancer metastases. Monoclonal antibodies, such as Herceptin against HER2-overexpressing cancers, have showed satisfactory clinical therapeutic effect. However, they have difficulty to surmount obstacles to enter cells or blood–brain barrier.
Results
In this study, a cell-penetrating peptide Arg9 was linked to the C-terminus of anti-HER2 single chain antibody (MIL5scFv). Flow cytometry, confocal microscopy and electron microscopy analysis all revealed that Arg9 peptide facilitated the penetration of MIL5scFv into HER2-negative cell line NIH3T3 and orientate in mitochondria. More interestingly, Western blot assay showed the potential enhanced bioactivity of MIL5scFv-Arg9 in HER2+ cell line SKOV3, indicating that Arg9 could help large molecules (e.g. antibody) to penetrate into cells and therefore enhance its anti-neoplastic function.
Conclusions
Our work represented an attractive by preliminary strategy to enhance the therapeutic effect of existing antibodies by entering cells easier, or more desirable, surmounting the physical barriers, especially in hard-to-reach cancers such as brain metastases cases.
doi:10.1186/1756-0500-5-336
PMCID: PMC3477046  PMID: 22748113
HER2; Single chain antibody; Translocation
5.  Defective anchoring of JNK1 in the cytoplasm by MKK7 in Jurkat cells is associated with resistance to Fas-mediated apoptosis 
Molecular Biology of the Cell  2011;22(1):117-127.
MKK7 works as a cytoplasmic anchoring protein for JNK1 in various cell lines but exhibits aberrant nuclear entry in Jurkat cells, which leads to resistance to Fas-mediated apoptosis.
The c-Jun N-terminal protein kinase (JNK) plays a context-dependent role in tumorigenesis. Stress-induced redistribution of JNK from the cytoplasm to the nucleus has been demonstrated as essential for stress-induced cell death. However, accumulation of basal JNK activity in the nucleus has frequently been seen in tumor cells. Our previous report revealed aberrant nuclear entry of JNK protein in Jurkat human leukemic T-cells even without JNK hyperactivation. Because inhibition of JNK activity, especially JNK1 activity, in Jurkat cells results in augmented Fas-mediated apoptosis, it is possible that aberrant subcellular localization of JNK, especially the JNK1 isoform, contributes to the resistance to Fas-mediated apoptosis. Here we report that MKK7 works as a cytoplasmic anchoring protein for JNK1 in various types of cells, including human peripheral blood mononuclear cell (PBMC) T-cells, but exhibits aberrant nuclear entry in Jurkat cells. Ectopic expression of a JNK1 mutant defective of nuclear entry or a nuclear JNK inhibitor leads to impaired UV-induced apoptosis in both PBMC T- and Jurkat cells. The same treatment shows no effect on Fas-mediated apoptosis of PBMC T-cells but sensitizes Jurkat cells to Fas-mediated apoptosis. Taken together, our work suggests that aberrant subcellular organization of the JNK pathway might render certain tumor cells resistant to Fas-mediated apoptosis.
doi:10.1091/mbc.E10-06-0492
PMCID: PMC3016969  PMID: 21148294
6.  Characterization of a Novel Anti-DR5 Monoclonal Antibody WD1 with the Potential to Induce Tumor Cell Apoptosis 
TNF-related apoptosis-inducing ligand (TRAIL) is a TNF family member capable of inducing apoptosis. Death receptor 5 (DR 5) is a key receptor of TRAIL and plays an important role in TRAIL-induced apoptosis. To prepare monoclonal antibodies (mAbs) against DR5, cDNA encoding soluble DR5 (sDR5) was firstly amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) with specific primers, and then inserted into a prokaryotic expression vector pET-30a. The recombinant plasmid was expressed in Escherichia coli strain BL21 (DE3), and sDR5 was purified by nickel affinity chromatography. As an antigen, sDR5 was used to immunize mice. Hybridomas secreting antibodies against sDR5 were identified. One positive clone was selected to produce antibody, WD1. ELISA and immunofluorescence demonstrated that WD1 could bind recombinant sDR5 and membranebound DR5 (mDR5) on Jurkat and Molt-4 cells. ATPLite assays showed that Jurkat and Molt-4 cells were sensitive to the antibody in a dose dependent manner. The Annexin V/PI assays and Giemsa's staining both showed that WD1 could induce Jurkat cell apoptosis efficiently. Transient transfection of 293T cells and indirect immunofluorescence assay demonstrated that mAb (WD1) couldn't cross-react with DR4. Our findings indicated that the novel antibody, WD1 could act as a direct agonist, bind DR5 characteristically, and initiate efficient apoptotic signaling and tumor regression. Thus, WD1 would be a leading candidate for potential cancer therapeutics.
doi:10.1038/cmi.2008.7
PMCID: PMC4072327  PMID: 18318995
TRAIL; death receptor 5; apoptosis; monoclonal antibody; ATPLite

Results 1-6 (6)