Interference of EFNA4 suppresses cell proliferation, invasion and angiogenesis in hepatocellular carcinoma by downregulating PYGO2.

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Ephrin A4 (EFNA4) acts as an oncogene in multiple cancers but is little known in HCC. It is revealed that EFNA4 is highly expressed in patients with HCC and influences the proliferation of HCC cells; however, detailed regulatory mechanism of EFNA4 in HCC needs to be unveiled. Here, we discovered that EFNA4 was highly expressed in HCC cell lines. EFNA4 knockdown greatly suppressed cell proliferation, migration and invasion, as well as inhibiting angiogenesis in Huh7 cells. EFNA4 was demonstrated to interact with pygopus-2 (PYGO2) and positively regulate PYGO2 expression. Gene gain- and loss-of-function experiments revealed that the anti-tumor effect of EFNA4 knockdown was partly abolished by PYGO2 overexpression. Furthermore, EFNA4 knockdown blocked wnt/ß-catenin signaling in Huh7 cells, which was then abolished by PYGO2. In conclusion, this study further ensured the oncogenic role of EFNA4 in HCC, and disclosed that EFNA4 knockdown suppressed cell proliferation, invasion, angiogenesis, and wnt/ß-catenin signaling in HCC by downregulating PYGO2.

NR4A1 knockdown confers hepatoprotection against ischaemia-reperfusion injury by suppressing TGFß1 via inhibition of CYR61/NF-κB in mouse hepatocytes.

Nuclear receptor subfamily 4, group A, member 1 (NR4A1) can aggravate ischaemia-reperfusion (I/R) injury in the heart, kidney and brain. Thus, the present study aimed to unravel the role of NR4A1 on hepatic I/R injury. For this purpose, the mouse hepatic I/R model and H/R-exposed mouse hepatocytes model were established to stimulate the hepatic and hepatocellular damage. Then, the levels of ALT and AST as well as TNF-α and IL-1ß expression were measured in the mouse serum and supernatant of hepatocyte s, respectively. Thereafter, we quantified the levels of NR4A1, CYR61, NF-kB p65 and TGFß1 under pathological conditions, and their interactions were analysed using ChIP and dual-luciferase reporter gene assays. The in vivo and in vitro effects of NR4A1, CYR61, NF-kB p65 and TGFß1 on I/R-induced hepatic and H/R-induced hepatocellular damage were evaluated using gain- and loss-of-function approaches. NR4A1 was up-regulated in the hepatic tissues of I/R-operated mice and in H/R-treated hepatocytes. Silencing NR4A1 relieved the I/R-induced hepatic injury, as supported by suppression of ALT and AST as well as TNF-α and IL-1ß. Meanwhile, NR4A1 knockdown attenuated the H/R-induced hepatocellular damage by inhibiting the apoptosis of hepatocyte s. Moreover, we also found that NR4A1 up-regulated the expression of CYR61 which resulted in the activation of the NF-κB signalling pathway, thereby enhancing the transcription of TGFß1, which was validated to be the mechanism underlying the contributory role of NR4A1 in hepatic I/R injury. Taken together, NR4A1 silencing reduced the expression of CYR61/NF-κB/TGFß1, thereby relieving the hepatic I/R injury.

Downregulation of miR-497-5p prevents liver ischemia-reperfusion injury in association with MED1/TIMP-2 axis and the NF-κB pathway.

Liver ischemia-reperfusion (I/R) injury is a common clinical pathological phenomenon, which is accompanied by the occurrence in liver transplantation. However, the underlying mechanism is not yet fully understood. MicroRNAs (miRNAs) play an important role in liver I/R injury. Therefore, the study of miRNAs function will contribute a new biological marker diagnosis of liver I/R injury. This study aims to evaluate effects of miR-497-5p in liver I/R injury in mice. The related regulatory factors of miR-497-5p in liver I/R injury were predicted by bioinformatics analysis. Vascular occlusion was performed to establish the liver I/R injury animal models. Hypoxia/reoxygenation (H/R) was performed to establish the in vitro models. Hematoxylin-eosin (HE) staining was conducted to assess liver injury. The inflammatory factors were evaluated by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was adopted to assess the cell apoptosis. The expression of miR-497b-5p was increased in liver I/R injury. Knockdown of miR-497b-5p inhibited the production of inflammatory factors and cell apoptosis. Overexpression of mediator complex subunit 1 (MED1) and tissue inhibitor of metalloproteinase 2 (TIMP2) inhibited cell apoptosis to alleviate liver I/R injury. miR-497b-5p could activate the nuclear factor kappa-B (NF-κB) pathway by inhibiting the MED1/TIMP-2 axis to promote liver I/R injury. This study may provide a new strategy for the treatment of liver I/R injury.

TM4SF1, a binding protein of DVL2 in hepatocellular carcinoma, positively regulates beta-catenin/TCF signalling.

The interaction between Axin and DVL2 is critical for the breaking down of the beta-catenin destruction complex and the activation of the Wnt/beta-catenin cascade. However, this biological process remains poorly understood. In the present study, TM4SF1 was identified as the interacting partner of DVL2 and positively regulated as Wnt/beta-catenin signalling by strengthening the DVL2-Axin interaction. The expression levels of TM4SF1 were elevated in hepatocellular carcinoma (HCC) and were induced by Kras signalling. The overexpression of TM4SF1 promoted the growth and motility of HCC cells, and up-regulated the target genes (Axin2 and cyclin D1). The down-regulation of TM4SF1 impaired the capability of HCC cells for growth, migration and metastasis. In addition, the down-regulation of TM4SF1 promoted the ubiquitination of beta-catenin. In summary, these results reveal the oncogenic functions of TM4SF1 in HCC progression and suggest that TM4SF1 might be a target for treatment.

Circular RNA hsa_circ_0004277 Stimulates Malignant Phenotype of Hepatocellular Carcinoma and Epithelial-Mesenchymal Transition of Peripheral Cells.

Accumulating evidence shows that exosomal circRNAs reflect the physiological status of donor cells, and various cell reactions are induced after exosomal circRNAs are captured by recipient cells. In this study, qRT-PCR was performed to detect circ-0004277 expression in hepatocellular carcinoma (HCC) cell lines, tissues, and plasma exosomes. The effects of circ-0004277 on the proliferation and migration of HCC cells were assessed by cell counting, 5-ethynyl-2'-deoxyuridine assays, Transwell migration assays, and tumor formation in nude mice. We found that circ-0004277 was significantly upregulated in HCC cells, tissues, and plasma exosomes compared to that in normal controls. Overexpression of circ-0004277 enhanced the proliferation, migration, and epithelial-mesenchymal transition (EMT) of HCC cells in vivo and in vitro. Furthermore, exosomes from HCC cells enhanced circ-0004277 expression in surrounding normal cells and stimulated EMT progression. ZO-1, a tight junction adapter protein, was downregulated in HCC tissues. In conclusion, our findings suggest that circ-0004277 promotes the malignant phenotype of HCC cells via inhibition of ZO-1 and promotion of EMT progression. In addition, exosomal circ-0004277 from HCC cells stimulates EMT of peripheral cells through cellular communication to further promote the invasion of HCC into normal surrounding tissues.

WDR34 Activates Wnt/Beta-Catenin Signaling in Hepatocellular Carcinoma.

BACKGROUND: Wnt ligand binding initiates the interaction between Frizzled and Dvl proteins. However, the regulation of Frizzled-Dvl proteins interaction remains largely unknown. AIMS: The present study aims to elucidate the regulation of Frizzled-Dvl interaction by WDR34. METHODS: The protein levels of WDR34 in hepatocellular carcinoma (HCC) tissues were examined by western blot and immunohistochemistry. The effects of WDR34 on the growth and migration of HCC cells were examined using MTT assay and Boyden chamber assay. The interaction between Frizzled and Dvl was evaluated by immunoprecipitation and GST pull-down assay. RESULTS: In this study, we have shown that WDR34, the binding protein of Frizzled (Fz) activated beta-catenin/TCF signaling by enhancing the interaction between Fz and Dvl2. WDR34 was found to up-regulate in HCC tissues, and its expression was negatively correlated with the survival of HCC patients. WDR34 promoted the growth, colony formation and migration of HCC cells. However, knocking down the expression of WDR34 inhibited the growth, colony formation and migration of HCC cells. CONCLUSION: Taken together, this study demonstrated the oncogenic roles of WDR34 in the progression of HCC and suggested that WDR34 might be a therapeutic target for HCC.

STIP1 is over-expressed in hepatocellular carcinoma and promotes the growth and migration of cancer cells.

Wnt/beta-catenin signaling is frequently activated in hepatocellular carcinoma (HCC). Better understanding the mechanism for its over-activation would help the therapy. In this study, we have shown that the stress-induced phosphoprotein 1 (STIP1) is up-regulated in the HCC tissues. Functional studies showed that STIP1 promoted the growth, colony formation and migration of cancer cells. However, knocking down the expression of STIP1 inhibited the growth, colony formation and migration of cancer cells. Molecular mechanism study showed that STIP1 interacted with Axin, enhanced the interaction between Axin and DVL2, thus activated beta-catenin/TCF signaling. Taken together, our study demonstrated the oncogenic roles of STIP1 in the progression of HCC, and suggested that STIP1 might be a therapeutic target.

NUP37, a positive regulator of YAP/TEAD signaling, promotes the progression of hepatocellular carcinoma.

Activation of YAP/TEAD signaling is very common in the progression of HCC (Hepatocellular carcinoma). Nuclear pore complex (NPC) regulates the shuttling of proteins between cytoplasm and nucleus. Nuclear accumulation of YAP protein has been observed in the majority of HCC tissues. However, whether NPC could regulate the YAP/TEAD signaling remains unknown. In this study, it was found NUP37, the component of NPC, significantly up-regulated in HCC clinical samples and mouse model. Over-expression of NUP37 promoted the growth, migration and invasion of HCC cells, while knocking down the expression of NUP37 inhibited the growth, migration, invasion and metastasis of HCC cells and improved the survival of the mouse model. NUP37 interacted with YAP and activated YAP/TEAD signaling by enhancing the interaction between YAP and TEAD. Taken together, these data demonstrated the oncogenic roles of NUP37 in the progression of HCC and suggested that NUP37 might be a promising therapeutic target.

PKMYT1 promoted the growth and motility of hepatocellular carcinoma cells by activating beta-catenin/TCF signaling.

Over-activation of beta-catenin/TCF signaling has been frequently observed in hepatocellular carcinoma (HCC). Better understanding the molecular mechanism for the aberrant activation of beta-catenin/TCF signaling would provide novel insights into the treatment of this malignancy. In this study, we have shown that the expression of PKMYT1 was up-regulated in HCC. PKMYT1 positively regulated the growth, migration, colony formation, metastasis and epithelia mesenchymal transition (EMT) of HCC cells. Mechanically, PKMTY1 activated the beta-catenin/TCF signaling by binding and inactivating GSK3beta. Taken together, our study demonstrated the oncogenic activity of PKMYT1 in the progression of HCC and suggested that PKMYT1 might be a therapeutic target.

CIZ1 interacts with YAP and activates its transcriptional activity in hepatocellular carcinoma cells.

Dysregulation of Hippo-Yes-associate protein (YAP) signaling has important roles in the tumorigenesis of hepatocellular carcinoma (HCC). Our previous studies have shown that Cip1 interacting zinc finger protein 1 (CIZ1) activated YAP signaling in the HCC cells and promoted the growth and migration of cancer cells. However, the mechanisms for the activation of YAP signaling by CIZ1 are unknown. In this study, it was found that CIZ1 interacted with the transcriptional factor YAP in HCC cells. The nuclear matrix anchor domain of CIZ1 is responsible for its interaction with YAP. Moreover, CIZ1 enhanced the interaction between YAP and TEAD. Knocking down the expression of CIZ1 impaired the transcriptional activity as well as the biological functions of YAP. Taken together, our study demonstrated that CIZ1 is a positive regulator of YAP signaling, and CIZ1 might be a therapeutic target for HCC.

CIZ1 is upregulated in hepatocellular carcinoma and promotes the growth and migration of the cancer cells.

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, and the prognosis for the HCC remains very poor. Although dys-regulation of CIZ1 (Cip1 interacting zinc finger protein 1) has been observed in various cancer types, its expression and functions in HCC remain unknown. In this study, the mRNA level of CIZ1 in the HCC tissues were examined using real-time polymerase chain reaction, and the effects of CIZ1 on the growth, migration, and metastasis of HCC cells were examined by crystal violet assay, Boyden chamber assay, and in vivo image system, respectively. In addition, the molecular mechanisms were investigated by luciferase assay. Upregulation of CIZ1 in the clinical HCC samples was observed. Forced expression of CIZ1 promoted the growth and migration of HCC cells, while knocking down the expression of CIZ1 inhibited the growth, migration, and metastasis of HCC cells. Molecular mechanism studies revealed that CIZ1 activated YAP/TAZ signaling in HCC cells. Taken together, our study demonstrated the oncogenic roles of CIZ1 in HCC cells and CIZ1 might be a promising therapeutic target for HCC.

LiverAtlas: a unique integrated knowledge database for systems-level research of liver and hepatic disease.

BACKGROUND: A large amount of liver-related physiological and pathological data exist in publicly available biological and bibliographic databases, which are usually far from comprehensive or integrated. Data collection, integration and mining processes pose a great challenge to scientific researchers and clinicians interested in the liver. METHOD: To address these problems, we constructed LiverAtlas (http://liveratlas.hupo.org.cn), a comprehensive resource of biomedical knowledge related to the liver and various hepatic diseases by incorporating 53 databases. RESULTS: In the present version, LiverAtlas covers data on liver-related genomics, transcriptomics, proteomics, metabolomics and hepatic diseases. Additionally, LiverAtlas provides a wealth of manually curated information, relevant literature citations and cross-references to other databases. Importantly, an expert-confirmed Human Liver Disease Ontology, including relevant information for 227 types of hepatic disease, has been constructed and is used to annotate LiverAtlas data. Furthermore, we have demonstrated two examples of applying LiverAtlas data to identify candidate markers for hepatocellular carcinoma (HCC) at the systems level and to develop a systems biology-based classifier by combining the differential gene expression with topological features of human protein interaction networks to enhance the ability of HCC differential diagnosis. CONCLUSION: LiverAtlas is the most comprehensive liver and hepatic disease resource, which helps biologists and clinicians to analyse their data at the systems level and will contribute much to the biomarker discovery and diagnostic performance enhancement for liver diseases.

Immunohistochemical expression and prognostic value of CD97 and its ligand CD55 in primary gallbladder carcinoma.

BACKGROUND: CD97 as a member of the EGF-TM7 family with adhesive properties plays an important role in tumor aggressiveness by binding its cellular ligand CD55, which is a complement regulatory protein expressed by cells to protect them from bystander complement attack. Previous studies have shown that CD97 and CD55 both play important roles in tumor dedifferentiation, migration, invasiveness, and metastasis. The aim of this study was to investigate CD97 and CD55 expression in primary gallbladder carcinoma (GBC) and their prognostic significance. METHODS: Immunohistochemistry was used to investigate the expression of CD97 and CD55 proteins in 138 patients with GBC. RESULTS: CD97 and CD55 were absent or only weakly expressed in the normal epithelium of the gallbladder but in 69.6% (96/138) and 65.2% (90/138) of GBC, respectively, remarkably at the invasive front of the tumors. In addition, CD97 and CD55 expressions were both significantly associated with high histologic grade (both P = 0.009), advanced pathologic T stage (P = 0.01 and 0.009, resp.) and clinical stage (both P = 0.009), and positive venous/lymphatic invasion (both P = 0.009). Multivariate analyses showed that CD97 (hazard ratio, 3.236; P = 0.02) and CD55 (hazard ratio, 3.209; P = 0.02) expressions and clinical stage (hazard ratio, 3.918; P = 0.01) were independent risk factor for overall survival. CONCLUSION: Our results provide convincing evidence for the first time that the expressions of CD97 and CD55 are both upregulated in human GBC. The expression levels of CD97 and CD55 in GBC were associated with the severity of the tumor. Furthermore, CD97 and CD55 expressions were independent poor prognostic factors for overall survival in patients with GBC.

Screening of autoantibodies as potential biomarkers for hepatocellular carcinoma by using T7 phase display system.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide. Autoantibodies to tumor-associated proteins in the serum profile, as new biomarkers, may improve the early detection of HCC. METHODS: In this study, we interrogated a HCC cDNA T7 phage library for tumor-associated proteins using biopan enrichment techniques with HCC patient and normal sera. The enrichment of tumor-associated proteins after biopanning was tested using plaque assay and immunochemical detection. The putative tumor-associated phage clones were collected for PCR and sequencing analysis. Identities of those selected sequences were revealed through the sequence BLAST program. The identified phage-expressed proteins were then used to develop phage protein ELISA to measure matching autoantibodies using 70 HCC patients, 50 chronic hepatitis patients, and 70 normal serum samples. The logistic regression model and leave-one-out validation were used to evaluate predictive accuracies with a single marker as well as with combined markers. RESULTS: Twenty-six phage-displayed proteins have sequence identity with known or putative tumor-associated proteins. Immunochemical reactivity of patient sera with phage-expressed proteins showed that the autoantibodies to phage-expressed protein CENPF, DDX3, HSPA4, HSPA5, VIM, LMNB1, and TP53 had statistical significance in HCC patients. Measurements of the seven autoantibodies combined in a logistic regression model showed that combined measurements of these autoantibodies was more predictive of disease than any single antibody alone, underscoring the importance of identifying multiple potential markers. CONCLUSION: Autoantibody in the serum profiling is a promising approach for early detection and diagnosis of HCC. The panel of autoantibodies appears preferable to achieve superior accuracy rather than an autoantibody alone, and may have significant relevance to tumor biology, novel drug development, and immunotherapies.

A systems biology-based classifier for hepatocellular carcinoma diagnosis.

AIM: The diagnosis of hepatocellular carcinoma (HCC) in the early stage is crucial to the application of curative treatments which are the only hope for increasing the life expectancy of patients. Recently, several large-scale studies have shed light on this problem through analysis of gene expression profiles to identify markers correlated with HCC progression. However, those marker sets shared few genes in common and were poorly validated using independent data. Therefore, we developed a systems biology based classifier by combining the differential gene expression with topological features of human protein interaction networks to enhance the ability of HCC diagnosis. METHODS AND RESULTS: In the Oncomine platform, genes differentially expressed in HCC tissues relative to their corresponding normal tissues were filtered by a corrected Q value cut-off and Concept filters. The identified genes that are common to different microarray datasets were chosen as the candidate markers. Then, their networks were analyzed by GeneGO Meta-Core software and the hub genes were chosen. After that, an HCC diagnostic classifier was constructed by Partial Least Squares modeling based on the microarray gene expression data of the hub genes. Validations of diagnostic performance showed that this classifier had high predictive accuracy (85.88∼92.71%) and area under ROC curve (approximating 1.0), and that the network topological features integrated into this classifier contribute greatly to improving the predictive performance. Furthermore, it has been demonstrated that this modeling strategy is not only applicable to HCC, but also to other cancers. CONCLUSION: Our analysis suggests that the systems biology-based classifier that combines the differential gene expression and topological features of human protein interaction network may enhance the diagnostic performance of HCC classifier.

Cytotoxicity, permeability, and inflammation of metal oxide nanoparticles in human cardiac microvascular endothelial cells: cytotoxicity, permeability, and inflammation of metal oxide nanoparticles.

Wide applications and extreme potential of metal oxide nanoparticles (NPs) increase occupational and public exposure and may yield extraordinary hazards for human health. Exposure to NPs has a risk for dysfunction of the vascular endothelial cells. The objective of this study was to assess the cytotoxicity of six metal oxide NPs to human cardiac microvascular endothelial cells (HCMECs) in vitro. Metal oxide NPs used in this study included zinc oxide (ZnO), iron(III) oxide (Fe(2)O(3)), iron(II,III) oxide (Fe(3)O(4)), magnesium oxide (MgO), aluminum oxide (Al(2)O(3)), and copper(II) oxide (CuO). The cell viability, membrane leakage of lactate dehydrogenase, intracellular reactive oxygen species, permeability of plasma membrane, and expression of inflammatory markers vascular cell adhesion molecule-1, intercellular adhesion molecule-1, macrophage cationic peptide-1, and interleukin-8 in HCMECs were assessed under controlled and exposed conditions (12-24 h and 0.001-100 µg/ml of exposure). The results indicated that Fe(2)O(3), Fe(3)O(4), and Al(2)O(3) NPs did not have significant effects on cytotoxicity, permeability, and inflammation response in HCMECs at any of the concentrations tested. ZnO, CuO, and MgO NPs produced the cytotoxicity at the concentration-dependent and time-dependent manner, and elicited the permeability and inflammation response in HCMECs. These results demonstrated that cytotoxicity, permeability, and inflammation in vascular endothelial cells following exposure to metal oxide nanoparticles depended on particle composition, concentration, and exposure time.

VEGFA+936C/T and -634G/C polymorphisms and gastric cancer risk: a meta-analysis.

AIM: To estimate the association of vascular endothelial growth factor A (VEGFA) +936C/T and -634G/C polymorphisms and gastric cancer (GC) risk, a meta-analysis was performed. A total of nine studies were identified with 2,281 GC cases and 2,820 controls. This meta-analysis indicated significant associations between the VEGFA -634G/C polymorphism and GC risk were found for GC versus GG (OR 1.21, 95% CI 1.03-1.42) and GG+CC versus GC (OR 0.78, 95% CI 0.68-0.90) overall, for GC versus GG (OR 1.68, 95% CI 1.19-2.35) and GC+CC versus GG (OR 1.54, 95% CI 1.13-2.10) among Europeans, and for GG+CC versus GC (OR 0.82, 95% CI 0.70-0.96) among Asians. No association were observed between GC risk and the variant genotypes of VEGFA +936C/T in different genetic models. In summary, the results suggest that the VEGFA -634G/C polymorphism may contribute to GC susceptibility.

Inhibition of tumorigenesis and invasion of hepatocellular carcinoma by siRNA-mediated silencing of the livin gene.

Livin, a member of the inhibitor of apoptosis protein family, is overexpressed in a variety of solid tumors and cancer cell lines. Livin overexpression has been reported in hepatocellular carcinoma (HCC), suggesting the biological significance of livin in HCC progression. However, the mechanisms of livin and the consequence of its down-regulation in HCC have not been fully elucidated. A small interfering RNA (siRNA) eukaryotic expression vector specific to livin was constructed by gene recombination, and the nucleic acid was sequenced. It was then transfected into the human HCC cell line SMMC-7721. RT-PCR and Western blotting were used to validate the gene-silencing efficiency of livin in SMMC-7721 cells. Stable clones were obtained by G418 screening. Using multiple cellular and molecular approaches, such as an apoptosis assay, MTT assay, flow cytometry, Western blotting and a migration assay, the effects of livin inhibition on cell growth, migration and the induction of apoptosis in SMMC-7721 cells were observed. The siRNA eukaryotic expression vector specific to livin was constructed by gene recombination, and efficiently decreased the mRNA and protein expression of livin. The targeted inhibition of livin strongly sensitized SMMC-7721 cells to pro-apoptotic stimuli, and was associated with caspase-3 activation. In addition, the MMT assay indicated that the silencing of livin inhibited the cell growth of SMMC-7721 cells by specifically inhibiting cell mitosis. The results also showed that the silencing of livin strongly reduced the invasive capacity of SMMC-7721 cells. The findings suggest that livin expression not only provides HCC cells with increased resistance to apoptotic stimuli, but also contributes significantly to the proliferation and invasive capacity of HCC cells. Inhibition of livin may be a potential targeted approach for the treatment of HCC.

Inhibiting colorectal carcinoma growth and metastasis by blocking the expression of VEGF using RNA interference.

Angiogenesis plays an essential role in tumor growth and metastasis and is a promising target for cancer therapy. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. The present study was designed to determine the role of VEGF in tumor growth and metastasis using RNA interference (RNAi) technology. Four small interfering RNA (siRNA) sequences for the VEGF gene were cloned into expression plasmids and transfected into human colorectal carcinoma (CRC) SW620 cells. Stable transfection of these plasmids decreased VEGF protein expression, leading to the potent suppression of tumor cell proliferation, migration, invasion, and angiogenesis in vitro. Furthermore, in subcutaneous and intrasplenic/portal injection models involving athymic nude mice, the tumor growth and metastasis of SW620 cells expressing VEGF siRNA were significantly inhibited compared with untransfected cells or cells transfected with control vector alone. Immunohistochemical analyses of tumor sections revealed a decreased vessel density and decreased VEGF expression in the animals where siRNA against VEGF were expressed. These results indicate that RNAi of VEGF can be an effective antiangiogenic strategy for CRC.

[Study of a multivariate statistical 5-ALA-based discrimination method for fluorescence spectra of colonic tissue of SD rats].

In order to diagnosis colon early cancer with laser-induced 5-ALA-PpIX fluorescence spectra, a multivariate statistical method to distinguish these fluorescence spectra acquired in vivo was developed. 343 spectra were collected from 8 normal SD rats, and 20 1,2-DMH-induced SD colon cancer models, and 12 second generation rats of induced rats. 150 min after trail intravenous injections of 5-ALA at a dose of 25 mg x kg(-1) BW, fluorescence spectra excited with 370 nm Ti-laser were collected in vivo. All spectra were divided into a calibration group and a prediction group. After preprocessing, 4 principal components were extracted with PCA. And then, discrimination models were built by stepwise multivariate logistic regression (SMLR) on calibration group. 3 pathological styles were combined each other, and then 3 SMLR models were derived. Normal tissues were classified from early cancers and advanced cancers with sensitivity of 100% and 98.4%, and specificity of 96% and 100%, and accuracy of 98% and 99.2% on prediction group, respectively. The multivariate statistical discrimination method of PCA and SMLR together can effectively distinguish normal tissues from early cancers and advanced cancers with high sensitivity and specificity by means of systemic 5-ALA at low dose. Laser induced fluorescence 5-ALA-based technique is promising for the detection of colonic early cancer.