Evaluation of the neoadjuvant chemotherapy response in osteosarcoma using the MRI DWI-based machine learning radiomics nomogram.

Objective: To evaluate the value of a nomogram combined MRI Diffusion Weighted Imaging (DWI) and clinical features to predict the treatment response of Neoadjuvant Chemotherapy (NAC) in patients with osteosarcoma. Methods: A retrospective analysis was conducted on 209 osteosarcoma patients admitted into two bone cancer treatment centers (133 males, 76females; mean age 16.31 ± 11.42 years) from January 2016 to January 2022. Patients were classified as pathological good responders (pGRs) if postoperative histopathological examination revealed ≥90% tumor necrosis, and non-pGRs if <90%. Their clinical features were subjected to univariate and multivariate analysis, and features with statistically significance were utilized to construct a clinical signature using machine learning algorithms. Apparent diffusion coefficient (ADC) values pre-NAC (ADC 0) and post two chemotherapy cycles (ADC 1) were recorded. Regions of interest (ROIs) were delineated from pre-treatment DWI images (b=1000 s/mm²) for radiomic features extraction. Variance thresholding, SelectKBest, and LASSO regression were used to select features with strong relevance, and three machine learning models (Logistic Regression, RandomForest and XGBoost) were used to construct radiomics signatures for predicting treatment response. Finally, the clinical and radiomics signatures were integrated to establish a comprehensive nomogram model. Predictive performance was assessed using ROC curve analysis, with model clinical utility appraised through AUC and decision curve analysis (DCA). Results: Of the 209patients, 51 (24.4%) were pGRs, while 158 (75.6%) were non-pGRs. No significant ADC1 difference was observed between groups (P>0.05), but pGRs had a higher ADC 0 (P<0.01). ROC analysis indicated an AUC of 0.681 (95% CI: 0.482-0.862) for ADC 0 at the threshold of ≥1.37×10-3 mm²/s, achieving 74.7% sensitivity and 75.7% specificity. The clinical and radiomics models reached AUCs of 0.669 (95% CI: 0.401-0.826) and 0.768 (95% CI: 0.681-0.922) respectively in the test set. The combined nomogram displayed superior discrimination with an AUC of 0.848 (95% CI: 0.668-0.951) and 75.8% accuracy. The DCA suggested the clinical utility of the nomogram. Conclusion: The nomogram based on combined radiomics and clinical features outperformed standalone clinical or radiomics model, offering enhanced accuracy in evaluating NAC response in osteosarcoma. It held significant promise for clinical applications.

Non-Contact Measurement and Identification Method of Large Flexible Space Structures in Low Characteristic Scenes.

The end-operation accuracy of the satellite-borne robotic arm is closely related to the satellite attitude control accuracy, and the influence of the vibration of the satellite's flexural structure on the satellite attitude control is not negligible. Therefore, a stable and reliable vibration frequency identification method of the satellite flexural structure is needed. Different from the traditional non-contact measurement and identification methods of large flexible space structures based on marker points or edge corner points, the condition of non-marker points relying on texture features can identify more feature points, but there are problems such as low recognition and poor matching of features. Given this, the concept of 'the comprehensive matching parameter' of scenes is proposed to describe the scene characteristics of non-contact optical measurement from the two dimensions of recognition and matching. The basic connotation and evaluation index of the concept are also given in the paper. Guided by this theory, the recognition accuracy and matching uniqueness of features can be improved by means of equivalent spatial transformation and novel relative position relationship descriptor. The above problems in non-contact measurement technology can be solved only through algorithm improvement without adding hardware devices. On this basis, the Eigensystem Realization Algorithm (ERA) method is used to obtain the modal parameters of the large flexible space structure. Finally, the effectiveness and superiority of the proposed method are verified by mathematical simulation and ground testing.

Porous Se@SiO2 Nanoparticles Enhance Wound Healing by ROS-PI3K/Akt Pathway in Dermal Fibroblasts and Reduce Scar Formation.

Hypertrophic scarring, which is characterized by excessive extracellular matrix deposition and abnormal fibroblast homeostasis, is an undesirable outcome of dermal wound healing. Once formed, the scar will replace the normal function of local skin, and there are few noninvasive clinical treatments that can cure it. Se@SiO2 nanoparticles were synthesized to suppress oxidative stress, which induced the presence and activation of myofibroblasts during wound recovery. The characterization, antioxidant capacity and biological safety of Se@SiO2 NPs were evaluated. A full-thickness excisional wound model was established, and the wounds were divided into three groups. The re-epithelization and distribution of collagen fibers were assessed using hematoxylin and eosin staining and Masson's trichome staining after specific treatments. Our results revealed that the Se@SiO2 NPs accelerated dermal wound healing and suppressed the formation of hypertrophic scars, accompanied by oxidative stress inhibition. Moreover, we found that Se@SiO2 NPs worked by activating the PI3K/Akt pathway and upregulating the phosphorylation of Akt. The findings of our study provide a new method to promote dermal scar-free wound healing by suppressing excessive oxidative stress and through PI3K/Akt pathway activation.

Machine Learning-Based Radiomics Nomogram With Dynamic Contrast-Enhanced MRI of the Osteosarcoma for Evaluation of Efficacy of Neoadjuvant Chemotherapy.

OBJECTIVES: This study aims to evaluate the value of machine learning-based dynamic contrast-enhanced MRI (DCE-MRI) radiomics nomogram in prediction treatment response of neoadjuvant chemotherapy (NAC) in patients with osteosarcoma. METHODS: A total of 102 patients with osteosarcoma and who underwent NAC were enrolled in this study. All patients received a DCE-MRI scan before NAC. The Response Evaluation Criteria in Solid Tumors was used as the standard to evaluate the NAC response with complete remission and partial remission in the effective group, stable disease, and progressive disease in the ineffective group. The following semi-quantitative parameters of DCE-MRI were calculated: early dynamic enhancement wash-in slope (Slope), time to peak (TTP), and enhancement rate (R). The acquired data is randomly divided into 70% for training and 30% for testing. Variance threshold, univariate feature selection, and least absolute shrinkage and selection operator were used to select the optimal features. Three classifiers (K-nearest neighbor, KNN; support vector machine, SVM; and logistic regression, LR) were implemented for model establishment. The performance of different classifiers and conventional semi-quantitative parameters was evaluated by confusion matrix and receiver operating characteristic curves. Furthermore, clinically relevant risk factors including age, tumor size and site, pathological fracture, and surgical staging were collected to evaluate their predictive values for the efficacy of NAC. The selected clinical features and imaging features were combined to establish the model and the nomogram, and then the predictive efficacy was evaluated. RESULTS: The clinical relevance risk factor analysis demonstrates that only surgical stage was an independent predictor of NAC. A total of seven radiomic features were selected, and three machine learning models (KNN, SVM, and LR) were established based on such features. The prediction accuracy (ACC) of these three models was 0.89, 0.84, and 0.84, respectively. The area under the subject curve (AUC) of these three models was 0.86, 0.92, and 0.93, respectively. As for Slope, TTP, and R parameters, the prediction ACC was 0.91, 0.89, and 0.81, respectively, while the AUC was 0.87, 0.85, and 0.83, respectively. In both the training and testing sets, the ACC and AUC of the combined model were higher than those of the radiomics models (ACC = 0.91 and AUC = 0.95), which indicate an outstanding performance of our proposed model. CONCLUSIONS: The radiomics nomogram demonstrates satisfactory predictive results for the treatment response of patients with osteosarcoma before NAC. This finding may provide a new decision basis to improve the treatment plan.

Multislice spiral computed tomography imaging in evaluating hemophilic arthropathy.

BACKGROUND: Certain hemophilia patients are unable to cooperate with or afford magnetic resonance imaging (MRI) examinations. The purpose of our study was to explore the value of multislice spiral computed tomography (MSCT) in evaluating hemophilic arthropathy (HA). METHODS: Thirty-eight patients with 73 joints of HA were consecutively selected from January 2016 to May 2018 for this prospective study. All 73 joints were examined by X-ray, CT, and MRI within 2 days. The MRI scores of the joints were determined by the International Prophylaxis Study Group (IPSG) standard. The CT findings were quantified according to the IPSG standard, except for cartilage injury, which was quantified by joint space narrowing using the X-ray Pettersson score. The CT and MRI scores were compared by the paired Wilcoxon signed-rank test. The correlations between the CT score of joint space narrowing and MRI score of cartilage injury and the total CT and MRI scores were analyzed by Spearman rank correlation. The kappa test was used to compare the consistency of CT and MRI scores. RESULTS: MRI was superior to CT based on the scores for small amount of effusion (P < 0.05), synovial hypertrophy and hemosiderin deposition in the mild groups (P < 0.05). The CT and MRI scores were not significantly different for moderate and massive effusion, synovial hypertrophy, and hemosiderin deposition in the moderate and severe groups, bone erosion or cystic changes (P > 0.05), and there was a high degree of consistency between the two scores (kappa > 0.81). The consistency between the Pettersson scores of joint space narrowing on CT and the IPSG scores of cartilage injury on MRI was high (kappa = 0. 774, P < 0.05). CONCLUSION: The image scores of MSCT are generally consistent with MRI except for mild synovitis, which can be used as an alternative for the evaluation of HA.

Using synovial volume measurement by MRI to evaluate the effect of 32P Radiation synovectomy on hemophilic arthropathy patients.

OBJECTIVE: To evaluate the potential of synovial membrane volume measurement by MRI in monitoring the effect of radiation synovectomy on patients of Hemophilic Arthropathy (HA). METHODS: We studied 63 diseased joints of 42 HA patients who received hospitalized services at the Hemophilia Diagnosis and Treatment Center of Henan Provincial People's Hospital from May 2011 to January 2015. Unenhanced and enhanced MR scanning of each diseased joint was performed simultaneously. The volumes of synovial membrane of 21 joints from 16 patients before and after being treated with 32P radiation synovectomy (PRS) were measured and compared using image post-processing software and workstation. Two sample matching t test was conducted to analyze the synovial membrane volumes of the same joint measured by unenhanced and enhanced MR, as well as change of MR enhancement ratio after treatments. RESULTS: The synovial membrane volumes measured by unenhanced versus enhanced MR scanning showed no statistical significance. Significant reduction (t = 7.831, p < 0.001) of the synovial membrane volume after treatment (2479.45±46.48 mm3 versus 2983.30±42.87 mm3 before treatment) was observed. MR enhancement ratio of synovial membrane decreased after treatment (0.92±0.06 after vs 1.17±0.07 before treatment) with statistical significance. CONCLUSION: The synovial membrane volume and MR enhancement ratio can be used to monitor patient response to PRS treatment.

Improved display of cervical intervertebral discs on water (iodine) images: incidental findings from single-source dual-energy CT angiography of head and neck arteries.

OBJECTIVE: To (a) assess the diagnostic performance of material decomposition (MD) water (iodine) images for the evaluation of cervical intervertebral discs (IVDs) in patients who underwent dual-energy head and neck CT angiography (HNCTA) compared with 70-keV images and (b) to explore the correlation of water concentration with the T2 relaxation time of IVDs. MATERIALS AND METHODS: Twenty-four consecutive patients who underwent dual-energy HNCTA and cervical spine MRI were studied. The diagnostic performance of water (iodine), 70-keV and MR images for IVD bulge and herniation was assessed. A subjective image score for each image set was recorded. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of IVDs to the cervical spinal cord were compared between water (iodine) and 70-keV images. Disc water concentration as measured on water (iodine) images was correlated with T2 relaxation time. RESULTS: IVD evaluations for bulge and herniation did not differ significantly among the three image sets (pairwise comparisons; all p > 0.05). SNR and CNR were significantly improved on water (iodine) images compared with those on 70-keV images (p < 0.001). Although water (iodine) images showed higher image quality scores when evaluating IVDs compared with 70-keV images, the difference is not significant (all adjusted p > 0.05). IVD water concentration exhibited no correlation with relative T2 relaxation time (all p > 0.05). CONCLUSION: Water (iodine) images facilitated analysis of cervical IVDs by providing higher SNR and CNR compared with 70-keV images. The disc water concentration measured on water (iodine) images exhibited no correlation with relative T2 relaxation time. KEY POINTS: • There was no significant difference in cervical IVD evaluations for bulge and herniation among water (iodine) images, 70-keV images and MR images. • Water (iodine) images provided higher objective and subjective image quality than 70-keV images, though the difference of subjective evaluation was not statistically significant. • The disc water concentration exhibited no correlation with relative T2 relaxation time, which reflects the inferiority of the water (iodine) images in evaluating disc water content compared with T2 maps.

The FOXK1-CCDC43 Axis Promotes the Invasion and Metastasis of Colorectal Cancer Cells.

BACKGROUND/AIMS: The CCDC43 gene is conserved in human, rhesus monkey, mouse and zebrafish. Bioinformatics studies have demonstrated the abnormal expression of CCDC43 gene in colorectal cancer (CRC). However, the role and molecular mechanism of CCDC43 in CRC remain unknown. METHODS: The functional role of CCDC43 and FOXK1 in epithelial-mesenchymal transition (EMT) was determined using immunohistochemistry, flow cytometry, western blot, EdU incorporation, luciferase, chromatin Immunoprecipitation (ChIP) and cell invasion assays. RESULTS: The CCDC43 gene was overexpressed in human CRC. High expression of CCDC43 protein was associated with tumor progression and poor prognosis in patients with CRC. Moreover, the induction of EMT by CCDC43 occurred through TGF-ß signaling. Furthermore, a positive correlation between the expression patterns of CCDC43 and FOXK1 was observed in CRC cells. Promoter assays demonstrated that FOXK1 directly bound and activated the human CCDC43 gene promoter. In addition, CCDC43 was necessary for FOXK1- mediated EMT and metastasis in vitro and vivo. Taken together, this work identified that CCDC43 promoted EMT and was a direct transcriptional target of FOXK1 in CRC cells. CONCLUSION: FOXK1-CCDC43 axis might be helpful to develop the drugs for the treatment of CRC.

[Value of endoscopic ultrasound-guided fine needle aspiration in pretest prediction and diagnosis of pancreatic ductal adenocarcinoma].

OBJECTIVE: To identify the predictive factors for differentiating pancreatic ductal adenocarcinoma (PDAC) from other neoplastic solid pancreatic lesions and assess the accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for diagnosis of PDAC. METHODS: We retrospectively analyzed the clinical data of patients referred for EUS-FNA evaluation of pancreatic lesions in the Digestive Endoscopic Center of Nanfang Hospital between January, 2009 and May, 2016. The cases with unknown diagnosis, missing data, repeated punctures, cystic lesions and benign lesions were excluded from the analysis. The positivity rates of EUS-FNA were compared between patients with PDAC and those with non-PDAC lesions, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS-FNA were assessed in the diagnosis of PDAC. Univariate and multivariate logistic regression analyses were used to identify the factors for differentiating PDAC from non-PDAC lesions based on the demographic characteristics, clinical presentations, laboratory data, and endoscopic ultrasonography imaging features of the patients. RESULTS: Among the 75 patients with solid neoplastic pancreatic lesions, 54 (72.0%) were found to have PDAC and 21 (28.0%) had non-PDAC lesions. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EUS-FNA for the diagnosis of PDAC were 77.8%, 100.0%, 100.0%, 63.6% and 84.0%, respectively. No significant difference was found in the positivity rate of EUS-FNA between patients with PDAC and those with non-PDAC lesions (77.8% vs 76.2%, P > 0.05). Multivariate regression analysis identified abdominal pain (OR=5.163, 95%CI: 1.093-24.389, P=0.038), lesion size (OR=0.926, 95%CI: 0.877-0.978, P=0.006), characteristics of the solid lesions (OR=7.105, 95%CI: 1.440-35.043, P=0.016), and evidence of metastases (OR=6.165, 95%CI: 1.332-28.533, P=0.020) as the independent factors for predicting PDAC. CONCLUSIONS: The pretest characteristics including abdominal pain, evidence of metastases, and lesion size and lesion characteristics defined by endoscopic ultrasonography findings can reliably predict a diagnosis of PDAC. EUS-FNA has a high sensitivity and a high specificity for the diagnosis of PDAC.

Diagnostic classification of endosonography for differentiating colorectal ulcerative diseases: A new statistical method.

AIM: To establish a classification method for differential diagnosis of colorectal ulcerative diseases, especially Crohn's disease (CD), primary intestinal lymphoma (PIL) and intestinal tuberculosis (ITB). METHODS: We searched the in-patient medical record database for confirmed cases of CD, PIL and ITB from 2008 to 2015 at our center, collected data on endoscopic ultrasound (EUS) from randomly-chosen patients who formed the training set, conducted univariate logistic regression analysis to summarize EUS features of CD, PIL and ITB, and created a diagnostic classification method. All cases found to have colorectal ulcers using EUS were obtained from the endoscopy database and formed the test set. We then removed the cases which were easily diagnosed, and the remaining cases formed the perplexing test set. We re-diagnosed the cases in the three sets using the classification method, determined EUS diagnostic accuracies, and adjusted the classification accordingly. Finally, the re-diagnosing and accuracy-calculating steps were repeated. RESULTS: In total, 272 CD, 60 PIL and 39 ITB cases were diagnosed from 2008 to 2015 based on the in-patient database, and 200 CD, 30 PIL and 20 ITB cases were randomly chosen to form the training set. The EUS features were summarized as follows: CD: Thickened submucosa with a slightly high echo level and visible layer; PIL: Absent layer and diffuse hypoechoic mass; and ITB: Thickened mucosa with a high or slightly high echo level and visible layer. The test set consisted of 77 CD, 30 PIL, 23 ITB and 140 cases of other diseases obtained from the endoscopy database. Seventy-four cases were excluded to form the perplexing test set. After adjustment of the classification, EUS diagnostic accuracies for CD, PIL and ITB were 83.6% (209/250), 97.2% (243/250) and 85.6% (214/250) in the training set, were 89.3% (241/270), 97.8% (264/270) and 84.1% (227/270) in the test set, and were 86.7% (170/196), 98.0% (192/196) and 85.2% (167/196) in the perplexing set, respectively. CONCLUSION: The EUS features of CD, PIL and ITB are different. The diagnostic classification method is reliable in the differential diagnosis of colorectal ulcerative diseases.

Slow-pull and different conventional suction techniques in endoscopic ultrasound-guided fine-needle aspiration of pancreatic solid lesions using 22-gauge needles.

AIM: To evaluate the cytological diagnostic capacity and sample quality of the slow-pull technique and compare them with different suction techniques. METHODS: From July 2010 to December 2015, 102 patients with pancreatic solid lesions who underwent endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) with 22-gauge needles were retrospectively evaluated. EUS-FNA diagnosis was based on a cytological examination, and final diagnosis was based on a comprehensive standard of cytological diagnosis, surgical pathology and clinical or imaging follow-up. Cytological specimens were characterized for cellularity and blood contamination. The cytological diagnostic capacity and sample quality of the slow-pull technique and suction techniques with 5-mL/10-mL/20-mL syringes were analyzed. RESULTS: Of all of the EUS-FNA procedures, the slow-pull technique and suction techniques with 5-mL/10-mL/20-mL syringes were used in 31, 19, 34 and 18 procedures, respectively. There were significant differences between these four suction techniques in terms of cytological diagnostic accuracy (90.3% vs 63.2% vs 58.8% vs 55.6%, P = 0.019), sensitivity (88.2% vs 41.7% vs 40.0% vs 36.4%, P = 0.009) and blood contamination (score ≥ 2 for 29.0% vs 52.6% vs 70.6% vs 72.2%, P = 0.003). The accuracy and sensitivity of the slow-pull technique were significantly higher than those of the suction techniques using 5-mL (P = 0.03, P = 0.014), 10-mL (P = 0.005; P = 0.006) and 20-mL syringes (P = 0.01, P = 0.01). Blood contamination was significantly lower in the slow-pull technique than in the suction techniques with 10-mL (P = 0.001) and 20-mL syringes (P = 0.007). CONCLUSION: The slow-pull technique may increase the cytological diagnostic accuracy and sensitivity with slight blood contamination during EUS-FNA when using 22-gauge needles for solid pancreatic masses.

Automated segmentation of liver and liver cysts from bounded abdominal MR images in patients with autosomal dominant polycystic kidney disease.

Liver and liver cyst volume measurements are important quantitative imaging biomarkers for assessment of disease progression in autosomal dominant polycystic kidney disease (ADPKD) and polycystic liver disease (PLD). To date, no study has presented automated segmentation and volumetric computation of liver and liver cysts in these populations. In this paper, we proposed an automated segmentation framework for liver and liver cysts from bounded abdominal MR images in patients with ADPKD. To model the shape and variations in ADPKD livers, the spatial prior probability map (SPPM) of liver location and the tissue prior probability maps (TPPMs) of liver parenchymal tissue intensity and cyst morphology were generated. Formulated within a three-dimensional level set framework, the TPPMs successfully captured liver parenchymal tissues and cysts, while the SPPM globally constrained the initial surfaces of the liver into the desired boundary. Liver cysts were extracted by combined operations of the TPPMs, thresholding, and false positive reduction based on spatial prior knowledge of kidney cysts and distance map. With cross-validation for the liver segmentation, the agreement between the radiology expert and the proposed method was 84% for shape congruence and 91% for volume measurement assessed by the intra-class correlation coefficient (ICC). For the liver cyst segmentation, the agreement between the reference method and the proposed method was ICC = 0.91 for cyst volumes and ICC = 0.94 for % cyst-to-liver volume.

KLF8 promotes tumorigenesis, invasion and metastasis of colorectal cancer cells by transcriptional activation of FHL2.

The transcription factor Krüppel-like factor (KLF)8 plays an important role in the formation of several human tumors, including colorectal cancer. We recently identified four-and-a-half LIM protein 2 (FHL2) as a critical inducer of the epithelial-to-mesenchymal transition (EMT) and invasion. However, the molecular mechanism by which KLF8 affects FHL2-mediated tumor proliferation, EMT and metastasis remains unknown. Here, we showed that KLF8 overexpression promoted EMT and metastatic phenotypes. KLF8 expression was stimulated by transforming growth factor (TGF)-ß1. Moreover, KLF8 acted as a potential EMT inducer by stimulating vimentin expression and inducing a loss of E-cadherin in stable KLF8-transfected cells. KLF8 overexpression induced a strong increase in FHL2 expression, and a positive correlation between the expression patterns of KLF8 and FHL2 was observed in CRC cells. Promoter reporter and chromatin immunoprecipitation (ChIP) assays demonstrated that KLF8 directly bound to and activated the human FHL2 gene promoter. However, siRNA-mediated repression of FHL2 in KLF8-overexpressing cells reversed the EMT and the proliferative and metastatic phenotypes. In vivo, KLF8 promoted FHL2-mediated proliferation and metastasis via orthotopic implantation. Taken together, this work identified KLF8-induced FHL2 activation as a novel and critical signaling mechanism underlying human breast/colorectal cancer invasion and metastasis.

Suppression of KLF8 induces cell differentiation and sensitizes colorectal cancer to 5-fluorouracil.

KLF8 is a member of the KLF transcription factor family that plays an important role in oncogenesis. However, the role of KLF8 in colorectal cancer remains unknown. The aims of the present study were to examine KLF8 expression in colorectal cancers, to determine the role of KLF8 in cell differentiation and to investigate the antiproliferative effect of KLF8 silencing. The expression of KLF8 and phospho-ERK proteins was analyzed, and the effects of KLF8 suppression on cell differentiation and growth were evaluated. In addition, the biological impact of KLF8 knockdown on colorectal cancer cells was investigated in vitro and in vivo. The expression of the KLF8 protein was higher in 10/14 (71.43%) fresh cancer tissues compared with adjacent normal tissues, and the blockade of ERK signaling by U0126 decreased the expression of KLF8 in a time- and dose-dependent manner. Furthermore, KLF8-siRNA induced the expression of carcinoembryonic antigen (CEA) and E-cadherin as well as the maturation of F-actin. KLF8 suppression inhibited serum-dependent, anchorage­dependent and -independent cell growth. Moreover, KLF8 silencing induced apoptosis and sensitized cancer cells to 5-fluorouracil (5-FU). A strong antitumorigenic effect by lenti-KLF8-shRNA, which was enhanced when combined with 5-FU treatment, was exerted in nude mice. Thus, KLF8 suppression induced cell differentiation and inhibited tumorigenesis.

Somatostatin ameliorates lipopolysaccharide-induced tight junction damage via the ERK-MAPK pathway in Caco2 cells.

Dysfunction of the epithelial barrier is an important pathogenic factor of inflammatory bowel disease and other inflammatory conditions of the gut. Somatostatin (SST) has been demonstrated to reduce local and systemic inflammation reactions and maintain the integrity of the blood-brain barrier (BBB). To determine the beneficial effect of SST on lipopolysaccharide (LPS)-induced damage of the tight junction (TJ) and its mechanisms, Caco2 cells pretreated with SST (1nM) or MEK inhibitor U0126 (10µM) were exposed to LPS. LPS significantly reduced the expression of TJ proteins in a dose-dependent way. LPS (100µg/ml) greatly induced Caco2 monolayer barrier dysfunction by decreasing transepithelial resistance and increasing epithelial permeability. Pretreatment with SST effectively improved the barrier dysfunction of Caco2 cells. SST significantly increased the expression of TJ proteins occludin and ZO-1 and inhibited the redistribution of TJ proteins due to LPS stimulation. Furthermore, SST decreased the LPS-induced phosphorylation of ERK1/2, and a selective MEK inhibitor markedly protected the barrier function against LPS disturbance by blocking the activation of the ERK-MAPK pathway in Caco2 cells. Besides, LPS significantly increased the mRNA level of SSTR5, which was partly inhibited by pretreatment with SST. In conclusion, the present study indicates that SST protects the Caco2 monolayer barrier against LPS-induced tight junction breakdown by down-regulating the activation of the ERK-MAPK pathway and suppression the activation of SSTR5.

A novel colon cancer gene therapy using rAAV­mediated expression of human shRNA-FHL2.

FHL2 (Four and a half LIM-only protein 2) has been identified as an oncogene in colon cancer and suppression of FHL2 induces cell differentiation and tumorigenesis in colon cancer cell lines. The aim of this study was to develop a novel and effective approach to knockdown FHL2, which can serve as a promising target of colon cancer therapy. Recombinant adeno-associated virus (rAAV) was generated bearing with FHL2-shRNA and transfected into LoVo cells. Cell cycle and growth were assessed. The interaction between FHL2 and G0/G1 cell cycle and growth was evaluated by flow cytometry, western blot analysis and WST-1 assay. We showed that suppression of FHL2 by rAAV-shRNA induced G0/G1 cell cycle arrest and inhibited cell growth. Apoptosis-related proteins and their activity was investigated at the same time. rAAV-FHL2­shRNA activated intrinsic and extrinsic apoptotic pathways and increased cell susceptibility to apoptotic stimuli by 5-FU. Moreover, a xenograft model was established to explore rAAV-FHL2-shRNA with 5-FU mediated tumorigenesis in vivo. A strong anti-tumorigenic effect of rAAV-FHL2-shRNA was shown in nude mice and this antitumor effect was enhanced when combined with 5-FU treatment. These findings implicate FHL2 as a cell cycle and growth modulator and thus inhibit apoptosis in colon cancer cells. rAAV-shRNA-FHL2 may serve as a novel and potent therapeutic or 5-FU co-therapeutic agent for colon cancer.

Inhibition of the transcription factor Sp1 suppresses colon cancer stem cell growth and induces apoptosis in vitro and in nude mouse xenografts.

The transcription factor specificity protein 1 (Sp1) plays a role in the development and progression of various types of human cancers, while cancer stem cells (CSCs) are important in cancer cell self-renewal, resistance to chemotherapy and metastatic potential. This study investigated the role of Sp1 in colon CSC growth and apoptosis. Colon CSCs were successfully enriched using special culture medium and identified by typical CSC gene expression. In a quiescent state, these CSCs formed spheres with slow proliferation; overexpressed Sp1, CD44, CD166 and CD133 proteins; upregulated mesenchymal markers; and a downregulated epithelial marker were noted. In ex vivo experiments, the Sp1 protein was expressed in 74.8% of colon cancer tissues, whereas it was expressed only in 42.2% of the distant normal colon mucosae. Furthermore, inhibition of SP1 expression using Sp1 siRNA or mithramycin A (MIT) led to marked suppression of CSC growth and induced apoptosis. In addition, the percentage of CD44+/CD166+ cells was significantly downregulated both in vivo and in vitro following Sp1 inhibition. In conclusion, Sp1 suppression attenuated the characteristics of colon CSCs. Thus, Sp1 inhibition may be potentially useful for the future development of a novel therapeutic strategy to control colon cancer.

Lack of any association between insertion/deletion (I/D) polymorphisms in the angiotensin-converting enzyme gene and digestive system cancer risk: a meta-analysis.

OBJECTIVE: To investigate the association between the gene polymorphisms of angiotensin-converting enzyme (ACE) and digestive system cancer risk. METHOD: A search was performed in Pubmed, Medline, ISI Web of Science and Chinese Biomedical (CBM) databases, covering all studies until Sep 1st, 2013. Statistical analysis was performed by using Revman5.2 and STATA 12.0. RESULTS: A total of 15 case-control studies comprising 2,390 digestive system cancer patients and 9,706 controls were identified. No significant association was found between the I/D polymorphism and digestive cancer risk (OR =0.93, 95%CI = (0.75, 1.16), P =0.53 for DD+DI vs. II). In the subgroup analysis by ethnicity and cancer type, no significant associations were found for the comparison of DD+DI vs. II. Results from other comparative genetic models also indicated a lack of associations between this polymorphism and digestive system cancer risks. CONCLUSIONS: This meta-analysis suggested that the ACE D/I polymorphism might not contribute to the risk of digestive system cancer.

Hepatocyte function within a stacked double sandwich culture plate cylindrical bioreactor for bioartificial liver system.

Bioartificial liver (BAL) system is promising as an alternative treatment for liver failure. We have developed a bioreactor with stacked sandwich culture plates for the application of BAL. This bioreactor design addresses some of the persistent problems in flat-bed bioreactors through increasing cell packing capacity, eliminating dead flow, regulating shear stress, and facilitating the scalability of the bioreactor unit. The bioreactor contained a stack of twelve double-sandwich-culture plates, allowing 100 million hepatocytes to be housed in a single cylindrical bioreactor unit (7 cm of height and 5.5 cm of inner diameter). The serial flow perfusion through the bioreactor increased cell-fluid contact area for effective mass exchange. With the optimal perfusion flow rate, shear stress was minimized to achieve high and uniform cell viabilities across different plates in the bioreactor. Our results demonstrated that hepatocytes cultured in the bioreactor could re-establish cell polarity and maintain liver-specific functions (e.g. albumin and urea synthesis, phase I&II metabolism functions) for seven days. The single bioreactor unit can be readily scaled up to house adequate number of functional hepatocytes for BAL development.

Identification of a functional p53 responsive element within the promoter of XAF1 gene in gastrointestinal cancer cells.

It has been reported that XAF1 expression in gastric cancer is negatively correlated with p53. Our purpose was to clarify the regulatory mechanism of p53 on XAF1 expression. The effects of overexpressed wild-type and mutant p53 on XAF1 expression were evaluated. Binding capacity of core XAF1 promoter sequence to the recombinant p53 protein was examined. Site-directed mutation of putative p53 binding sequence and p53 knockdown by siRNA were performed. The protein expression and promoter activities of XAF1 in cells with null p53 were higher than that with wild-type and mutant p53. Ectopic overexpression of wild-type p53 suppressed XAF1 expression. A half-site (-95 to -86 nt) and a quarter-site (-4 to +1 nt) of p53 responsive element were found within XAF1 promoter. Both sequences bound to recombinant p53 effectively and specifically. Site-mutation of p53 responsive sequences abrogated the binding capacity. However, only the mutation of half-site increased XAF1 promoter activities. Suppression of p53 not only decreased the binding capacity of p53 responsive halfsite but also increased XAF1 transcription. In conclusion, we demonstrated that p53 could suppress the transcription of XAF1 through interaction with a high affinity responsive element (-95 to -86 nt) within XAF1 promoter, indicating a novel exclusive mechanism between these two tumor suppressors.