[Corrigendum] Fully human VEGFR2 monoclonal antibody BC001 attenuates tumor angiogenesis and inhibits tumor growth.

Subsequently to the publication of the above paper, an interested reader drew to the authors' attention that, for the scratch wound assay experiments shown in Fig. 1 on p. 2413, the panels showing the '0 h' experiments for the respective incubations with VEGF or BC001 were apparently identical. The authors were able to re­examine their original data files, and realized that this figure had been inadverently assembled incorrectly. The revised version of Fig. 1, containing the correct data for the '0 h / BC001' panel, is shown below. Note that the revisions made to this figure do not affect the overall conclusions reported in the paper. The authors are grateful to the Editor of International Journal of Oncology for allowing them the opportunity to publish this Corrigendum, and apologize to the readership for any inconvenience caused. [International Journal of Oncology 45: 2411­2420, 2014; DOI: 10.3892/ijo.2014.2690].

Neuroprotective Effects of Oxymatrine via Triggering Autophagy and Inhibiting Apoptosis Following Spinal Cord Injury in Rats.

Spinal cord injury (SCI) is a devastating neurological disorder characterized by high morbidity and disability. However, there is still a lack of effective treatments for it. The identification of drugs that promote autophagy and inhibit apoptosis in neurons is critical for improving patient outcomes following SCI. Previous studies have shown that increasing the activity of silent information regulator 1 (SIRT1) and downstream protein AMP-activated protein kinase (AMPK) in rat models of SCI is highly neuroprotective. Oxymatrine (OMT), a quinolizidine alkaloid, has exhibited neuroprotective effects in various central nervous system (CNS) diseases. However, its explicit effect and molecular mechanism in SCI are still unclear. Herein, we aimed to investigate the therapeutic effects of OMT and explore the potential role of autophagy regulation following SCI in rats. A modified compressive device (weight 35 g, time 5 min) was applied to induce moderate SCI in all groups except the sham group. After treatment with drugs or vehicle (saline), our results indicated that OMT treatment significantly reduced the lesion size, promoted survival of motor neurons, and subsequently attenuated motor dysfunction following SCI in rats. OMT significantly enhanced autophagy activity, inhibited apoptosis in neurons, and increased SIRT1 and p-AMPK expression levels. Interestingly, these effects of OMT on SCI were partially prevented by co-treatment with SIRT1 inhibitor EX527. Furthermore, combining OMT with the potent autophagy inhibitor chloroquine (CQ) could effectively abolish its promotion of autophagic flux. Taken together, these data revealed that OMT exerts a neuroprotective role in functional recovery against SCI in rats, and these effects are potentially associated with OMT-induced activation of autophagy via the SIRT1/AMPK signaling pathway.

Effect of translation and rotation fitting on analysis of corneal topography.

The purpose was to assess the suitability of quadratic equations for the accurate representation of corneal topography and consider the effect of translation and rotation fitting on the quality of fit and the curvature results. Topography images were recorded for the anterior and posterior surfaces of 490 corneas of 490 myopic patients using Pentacam. Elevation data were fitted to four shape models, three of which considered translational and/or rotational fitting. Differences between the models in the estimates of radii of curvature (R) and asphericity coefficients (Q) and in the quality of fit (as measured by the root mean square (RMS) error and the structural similarity index (SSIM)) were statistically analysed. The general shape model that considered both translational and rotational misalignments provided the best fit for the anterior (RMS = 1.18 ± 0.56 µm, SSIM = 0.99 ± 0.01) and posterior (RMS 3.64 ± 1.23 µm, SSIM = 0.99 ± 0.01) corneal surfaces in all subjects. The quality of fit degraded significantly (with p < 0.01 in all cases) when misalignments were not considered, increasing RMS to 5.20 ± 2.27 µm (anterior) and 17.10 ± 6.08 µm (posterior) and decreasing SSIM to 0.84 ± 0.18 (anterior) and 0.68 ± 0.22 (posterior) when both translational and rotational misalignments were ignored. The estimates of Rx, Ry, Qx and Qy as obtained when both forms of misalignment were considered varied, respectively, by as much as 0.18 mm, 0.23 mm, 0.27 and 0.54 for the anterior surface, and 0.25 mm, 0.39 mm, 0.32 and 0.37 for the posterior surface when misalignments were ignored. The variations were statistically significant, with p remaining below 0.01 in all cases. In conclusion, consideration of geometric misalignments helps improve the accuracy of describing corneal topography. The effects of misalignments on the estimates of corneal radius and asphericity are statistically significant and may in some cases be clinically significant.

Fully human VEGFR2 monoclonal antibody BC001 attenuates tumor angiogenesis and inhibits tumor growth.

The critical role of VEGFR2 in tumor neovascularization and progression has allowed the design of clinically beneficial therapies based on it. Here we show that BC001, a new fully human anti-VEGFR2 monoclonal antibody, inhibits VEGF-stimulated endothelial cell migration, tube formation, and effectively suppressed the transdifferentiation of cancer stem cells into endothelial cells in vitro. Since BC001 exhibited no activity against the mouse VEGFR2 and mouse based study was required to confirm its efficacy in vivo, BC101, the mouse analogue of BC001, was developed. BC101 significantly attenuated angiogenesis according to Matrigel plug assay and resulted in ~80% growth inhibition of mouse B16F10 homograft tumors relative to vehicle control. Similarly, human analogue BC001 suppressed the growth of human xenograft tumors HCT116 and BGC823. Furthermore, immunohistochemical results showed reduced expression of CD31, VEGFR2 and Ki-67, as well as increased expression of Caspase 3 in BC001-treated tumor, which indicated BC001 was able to significantly decrease microvessel density, suppress proliferation and promote apoptosis. These results demonstrate the fully human VEGFR2 monoclonal antibody BC001 can work as an effective inhibitor of tumor angiogenesis and tumor growth both in vitro and in vivo.

Down-regulation of some miRNAs by degrading their precursors contributes to anti-cancer effect of mistletoe lectin-I.

BACKGROUND AND PURPOSE: Mistletoe lectin-I (ML-I), the main anti-cancer component of mistletoe extracts, was originally thought to act exclusively on 28S rRNA. Here, we investigate the down-regulating effect and mechanism of CM-1, an ML-I isolated from Chinese mistletoe, on some miRNAs. EXPERIMENTAL APPROACH: The anti-cancer effects of CM-1 were assessed in vitro and in vivo in colorectal cancer cells. The miRNAs down-regulated by CM-1 were identified by miRNA microarray assay and validated by qRT-PCR analysis. The suppression of host gene transcription or by degradation of precursors was determined by qRT-PCR and enzyme activity assays respectively. The qRT-PCR, Western blot and immunohistochemistry were used to examine the expression of their target gene and related downstream effector. Cell proliferation was assayed in stably transfected HEK-293 cells with different levels of these miRNAs. KEY RESULTS: CM-1 showed prominent anti-neoplastic activity towards CLY and HT-29 cells both in vitro and in vivo. The miR-135a&b were the miRNAs most down-regulated by CM-1. Their host gene transcription was largely up-regulated, while their precursors were degraded directly by CM-1. The expression of their target gene adenomatous polyposis coli and the phosphorylation of related effector ß-catenin were both significantly up-regulated. The IC(50) values of CM-1 on derivative HEK-293 cells with high miR-135a&b levels were 2-4 times lower than that of control cells. CONCLUSIONS AND IMPLICATIONS: CM-1 down-regulated some miRNAs by degrading their precursors, which contributes to its prominent anti-cancer activity.

Differential sensitivity of colorectal cancer cell lines to artesunate is associated with expression of beta-catenin and E-cadherin.

Artesunate, a remarkable antimalarial agent, also reveals profound cytotoxic activity. In the present investigation, we compared the anticancer effects of artesunate on three colorectal cancer cell lines and analyzed the relationship between drug sensitivity and malignant phenotype of the tumor cells. The findings are as follows: poorly-differentiated was colorectal cancer cell line CLY showing nuclear beta-catenin accumulation and loss of E-cadherin; moderately-differentiated were Lovo cells with cytoplasmic distribution of the two proteins; and well-differentiated were HT-29 cells with membranous localization of them. Also, both in vitro and in vivo, poorly- or moderately-differentiated CLY and Lovo were more susceptible to artesunate treatment than well-differentiated HT-29. Furthermore, the sensitive response of CLY and Lovo to artesunate was associated with membranous translocation of beta-catenin and increased expression of E-cadherin, which indicated the inhibition of hyperactive Wnt signaling pathway and the reversion of the epithelial to mesenchymal transition, respectively. Due to the vital roles of Wnt pathway and the epithelial to mesenchymal transition in tumor differentiation, we thought artesunate could promote the re-differentiation and apoptosis of colorectal cancer cells by inhibition of hyperactive Wnt pathway and reversion of the epithelial to mesenchymal transition.

Artesunate attenuates the growth of human colorectal carcinoma and inhibits hyperactive Wnt/beta-catenin pathway.

Artesunate (ART), a remarkable antimalarial agent, also inhibited the growth of human colorectal carcinoma. As determined by MTT assay, flow cytometry analysis on apoptosis and indirect immunofluorescence analysis on the proliferation-associated marker Ki67, ART suppressed the proliferation and promoted the apoptosis of colorectal cancer cells in a dose-dependent manner. Furthermore, immunofluorescence analysis on beta-catenin and RT-PCR analysis on Wnt/beta-catenin target genes demonstrated ART translocated beta-catenin from nucleus to adherent junctions of membrane and reduced transcription mediated by beta-catenin. These results suggested the anticancer activity of ART correlated with the inhibition of hyperactive Wnt/beta-catenin signaling pathway. In vivo, ART significantly slowed the growth of colorectal tumor xenografts. Bioluminescent imaging also revealed that ART decreased the physiological activity of tumor xenografts and delayed spontaneous liver metastasis. These antitumor effects were related to the membranous translocation of beta-catenin and the inhibition of the unrestricted activation of Wnt/beta-catenin pathway, which was confirmed by the immunohistochemical staining of tumor tissues. These results and the known low toxicity are clues that ART might be a promising candidate drug for the treatment of colorectal carcinoma.

Establishment and characterization of a novel human colorectal cancer cell line (CLY) metastasizing spontaneously to the liver in nude mice.

Colorectal cancer (CRC) with liver metastasis is a fatal disease with rapid progression and poor patient outcome. However, the molecular mechanism involved in liver metastasis of CRC remains essentially unknown, largely because of the presence of few available CRC cell lines with liver metastasis origin and spontaneous metastatic potentials in nude mice. In this study, we established a novel metastatic CRC cell line, CLY, derived from liver metastasis of a 64-year-old Chinese CRC patient. The cell line was characterized by morphology, growth kinetics, tumorigenicity, spontaneous liver metastatic potential, and cytogenetics. Immunofluorescence analysis of beta-catenin and E-cadherin and methylation-specific PCR (MSP) of the E-cadherin gene (CDH1) promoter were also used to compare CLY with conventional CRC cell lines (HT-29 and Lovo). CLY exhibited compact and polygonal-shaped epithelial cells in vitro and its population doubling time was 29.5 h. Subcutaneous transplantation of CLY into nude mice resulted in subcutaneous tumor formation and spontaneous liver metastasis in all of 10 nude mice. Cytogenetic analysis identified aneuploidy karyotypes with a modal chromosome number of 60. In immunofluorescence analysis, CLY exhibited a low expression but high restricted nuclear localization of beta-catenin and a silenced expression of E-cadherin, which may be induced by hypermethylation of the E-cadherin gene (CDH1) promoter and differed from conventional CRC cell lines. Therefore, CLY is an ideal cell model for further exploring the metastatic mechanisms of CRC and testing new therapeutic reagents for CRC with liver metastasis.