Decoding Multi-DoF Movements Using a CST-Based Force Generation Model With Single-DoF Training.

Recent developments in dexterous myoelectric prosthetics have established a hardware base for human-machine interfaces. Although pattern recognition techniques have seen successful deployment in gesture classification, their applications remain largely confined to certain specific discrete gestures. Addressing complex daily tasks demands an immediate need for precise simultaneous and proportional control (SPC) for multiple degrees of freedom (DoFs) movements. In this paper, we introduce an SPC approach for multi-DoF wrist movements using the cumulative spike trains (CSTs) of motor unit pools, merely leveraging single-DoF training. The efficacy of our proposed approach was validated offline against existing methods respectively based on non-negative matrix factorization and motor unit spike trains, using experimental data. The experimental process includes both single-DoF (for training) and multi-DoF (for testing) movements. We evaluated the performance using Pearson correlation coefficient (R) and the normalized root mean square error (nRMSE). The results reveal that our method outperforms comparative approaches in force estimation for both testing datasets (3 and 4). On average, for dataset 3, R and nRMSE of the flexion/extension DoF (the pronation/supination DoF) are 0.923±0.037 (0.901±0.040) and 12.3±3.1% (12.9±2.2%); similarly, those of dataset 4 are 0.865±0.057 (0.837±0.053) and 14.9±2.9% (15.4±2.0%), respectively. The outcomes demonstrate the effectiveness of our method in simultaneous and proportional force estimation for multi-DoF wrist movements, showing a promising potential as a neural-machine interface for SPC of dexterous myoelectric prostheses.

ASSOCIATION BETWEEN RETINAL PIGMENT EPITHELIUM TEAR AND ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY: A Systematic Review and Meta-Analysis.

PURPOSE: To identify the prevalence of retinal pigment epithelium tear (RPET) after anti-vascular endothelial growth factor (VEGF) therapy and determine the efficacy of continued anti-VEGF therapy in patients with RPET. METHODS: All relevant clinical trials and observational studies in several online databases were screened. The main outcomes were the incidence of RPET after anti-VEGF therapy and changes in visual acuity for patients with RPET treated with continued anti-VEGF. RESULTS: The pooled incidence of RPET after anti-VEGF therapy from 24 studies with 17,354 patients was 1.9% (95% CI: 1.3-2.7). Most new RPET cases were concentrated in the first month at baseline or after the first injection during anti-VEGF therapy and gradually decreased by the subsequent month or injection. 13 studies with 157 patients reported that for patients who received anti-VEGF therapy after RPET, their pooled best-corrected visual acuity improved, but did not reach a significant level (standardized mean differences 0.34; 95% CI: -0.03 to 0.71). CONCLUSION: The incidence of RPET after anti-VEGF therapy is low. The intravitreal anti-VEGF injection may accelerate this process. For patients with RPET, maintenance of anti-VEGF therapy ensures visual acuity stability.

Cumulative Spike Train Estimation for Muscle Excitation Assessment From Surface EMG Using Spatial Spike Detection.

Estimating cumulative spike train (CST) of motor units (MUs) from surface electromyography (sEMG) is essential for the effective control of neural interfaces. However, the limited accuracy of existing estimation methods greatly hinders the further development of neural interface. This paper proposes a simple but effective approach for identifying CST based on spatial spike detection from high-density sEMG. Specifically, we use a spatial sliding window to detect spikes according to the spatial propagation characteristics of the motor unit action potential, focusing on the spikes of activated MUs in a local area rather than those of a specific MU. We validated the effectiveness of our proposed method through an experiment involving wrist flexion/extension and pronation/supination, comparing it with a recognized CST estimation method and an MU decomposition based method. The results demonstrated that the proposed method obtained higher accuracy on multi-DoF wrist torque estimation leveraging the estimated CST compared to the other three methods. On average, the correlation coefficient (R) and the normalized root mean square error (nRMSE) between the estimation results and recorded force were 0.96 ± 0.03 and 10.1% ± 3.7%, respectively. Moreover, there was an extremely high interpretive extent between the CSTs of proposed method and the MU decomposition method. The outcomes reveal the superiority of the proposed method in identifying CSTs and can provide promising driven signals for neural interface.

Global prevalence of myopic macular degeneration in general population and patients with high myopia: A systematic review and meta-analysis.

The prevalence of myopic macular degeneration (MMD) in the general population and patients with high myopia worldwide has not been fully investigated. Therefore, we screened all population-based studies that reported the prevalence of MMD, and pooled prevalence of MMD using a random-effect model. Subgroup analyses were performed to explore the differences in MMD prevalence in the general population and patients with high myopia according to ethnicity, region of residence (urban/rural), and grading system. Finally, 16 studies were included in this meta-analysis. Results obtained from 2,963 patients from seven countries on four continents indicated that the pooled prevalence of MMD in patients with high myopia was 49.0% (95% CI: 31.5%-66.7%). Results obtained from 71,052 participants from 10 countries on four continents suggested that the pooled prevalence of MMD in the general population was 1.7% (95% CI: 1.1%-2.6%). In the general population, living in urban areas and East Asians were associated with a high prevalence of MMD. Among patients with high myopia, only East Asians were at a higher risk of developing MMD. In conclusion, MMD was particularly prevalent in patients with high myopia. Compared with Europeans, East Asians (Chinese and Japanese) have a higher propensity of developing MMD, both in the general population and in patients with high myopia. It remains unclear whether the higher prevalence of MMD in patients with high myopia in East Asia is caused by differences in given age or given degree of myopia.Systematic review registration number: 202270014 (INPLASY.COM).

Comparison of the second-line treatments for patients with small cell lung cancer sensitive to previous platinum-based chemotherapy: A systematic review and Bayesian network analysis.

Objective: It remains unclear what the best second-line treatment is for patients with small-cell lung cancer sensitive to previous platinum-based chemotherapy. Methods: We systematically screened randomized controlled trials from several online databases. The primary outcome was objective response rate (ORR), and the secondary outcomes were disease control rate (DCR), overall survival (OS), progression-free survival (PFS), and hematological complications graded 3 to 5. The efficacy of included treatments was ranked by surface under the cumulative ranking curve (SUCRA) value. Results: We included eleven trials involving 1560 patients in quantitative analysis. Triple chemotherapy containing platinum (TP, combination of cisplatin, etoposide, and irinotecan) was associated with favorable ORR (intravenous topotecan vs TP; odds ratio: 0.13, 95% CI:0.03-0.63; SUCRA, 0.94) and PFS (vs intravenous topotecan; hazard ratio, 0.5; 95% CI: 0.25-0.99; SUCRA, 0.90). Belotecan ranked highest for OS (SUCRA, 0.90), while intravenous topotecan plus Ziv-aflibercept ranked highest for DCR (SUCRA, 0.75). TP was more likely to cause anemia and thrombocytopenia while intravenous topotecan plus Ziv-aflibercept resulted in most neutrocytopenia. Conclusion: TP is the first recommendation for the second-line treatment of sensitive relapsed SCLC. TP achieved priority in ORR and PFS with the most frequent adverse effects in anemia and thrombocytopenia. For patients who cannot tolerate the hematological adverse effects of triple chemotherapy, amrubicin is an optional option. Amrubicin had relatively good ORR and PFS, accompanied by fewer hematological complications. The rechallenge of the platinum doublet is inferior to amrubicin in ORR, DCR, and PFS. Oral topotecan has a similar effect compared with IV topotecan, but oral topotecan was associated with slightly higher safety and less stress in nursing. Belotecan contributed to the best PFS with slightly better safety but was not ideal in other outcomes. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022358256.

Protective effects of equol on the cartilage and subchondral bone in ovariectomized rats with osteoarthritis.

Objectives: This study aimed to determine the therapeutic effect of equol (EQ) on osteoporotic osteoarthritis (OP OA). Materials and Methods: Thirty-six 12-week-old female Sprague-Dawley rats were randomly divided into sham group, OP OA group, and EQ group (n=12). OP OA was induced by anterior cruciate ligament transection (ACLT) combined with ovariectomy (OVX). EQ was orally administrated (10 µg/g/day) after the operation for 12 weeks. The efficacy was evaluated by gross pathology and histopathologic evaluation. The underlying mechanism was investigated by immunohistochemical analysis, micro-computed tomography (micro-CT) scanning, and tartrate-resistant acid phosphatase (TRAP) staining. Results: EQ effectively retarded cartilage degeneration, decreased the levels of matrix metalloproteinases-13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), nuclear factor-kappa B P65 (NF-κB P65) and caspase-3, and increased the levels of collagen type II (Col-II), Col-I, aggrecan (AGG), and inhibitor of NF-κB α (IκBα) in the cartilage. In addition, EQ increased bone mineral density, improved the microstructural parameters of the subchondral bone (SB), and decreased the number of osteoclasts. Conclusion: EQ exerted a chondroprotective effect on OP OA in rats, associated with inhibition of the NF-κB signaling pathway and chondrocyte apoptosis. Furthermore, EQ showed an osteoprotective effect on SB via inhibiting osteoclastic activities.

Hazard Classification and Stability Analysis of High and Steep Slopes from Underground to Open-Pit Mining.

The stability of high and steep slopes in open-pit mines is closely related to the mine operations and the lives of the surrounding residents, so it is important to ensure the safety and stability of the slopes. Hazard classification and stability analysis of high and steep slopes under different working conditions are studied using the Shizhuyuan non-ferrous metal mine from underground to open-pit mining as a typical example. Firstly, data on rock mechanics parameters were obtained through site investigation and sampling. Then, the slope model of the open-pit mine was established and some slopes were selected in the model for qualitative and quantitative analysis. The strength reduction method and the limit equilibrium method were used to calculate the safety factor under each working condition and point out the potential instability areas. The results show that the selected slopes are safe and stable under all working conditions. Finally, on the premise of maintaining the safety and stability of the mine, the final slope angle was optimized from the original 45°21'35″ to 55°30'41″ to reduce production costs and increase mining efficiency. The final open-pit boundary that meets the stability requirements was eventually obtained.

Evaluation Method of the Vibration Reduction Effect Considering the Real Load- and Frequency-Dependent Stiffness of Slab-Track Mats.

The purpose of this research was to investigate and improve the accuracy of the existing slab-track mat (STM) specifications in the evaluation of the vibration reduction effect. The static nonlinearity and dynamic mechanical characteristics of three types of STMs were tested, and then a modified fractional derivative Poynting-Thomson (FDPT) model was used to characterize the preload and frequency dependence. A modified vehicle-floating slab track (FST) coupled dynamic model was established to analyze the actual insertion loss. The insertion loss error evaluated by the frequency-dependent tangent stiffness increased with the increase in STM nonlinearity, and the error obtained by the third preload tangent stiffness was usually greater than that of the second preload. Compared with the secant stiffness, the second preload frequency-dependent tangent stiffness was more suitable for evaluating STMs with high-static-low-dynamics (HSLD) stiffness. In order to reflect the frequency dependence effect and facilitate engineering applications, it is recommended that second preload tangent stiffness corresponding to the natural frequency of the FST be used for evaluation. Furthermore, the insertion loss of the STMs with monotonically increased stiffness decreased as the axle load increased, and the opposite was true for the STMs with monotonically decreased stiffness. The vibration isolation efficiency of the STMs with HSLD stiffness was both stable and better than that of the STMs with monotonic stiffness.

Norcantharidin inhibits tumor growth and vasculogenic mimicry of human gallbladder carcinomas by suppression of the PI3-K/MMPs/Ln-5γ2 signaling pathway.

BACKGROUND: Vasculogenic mimicry (VM) is a novel tumor blood supply in some highly aggressive malignant tumors. Recently, we reported VM existed in gallbladder carcinomas (GBCs) and the formation of the special passage through the activation of the PI3K/MMPs/Ln-5γ2 signaling pathway. GBC is a highly aggressive malignant tumor with disappointing treatments and a poor prognosis. Norcantharidin (NCTD) has shown to have multiple antitumor activities against GBCs, etc; however the exact mechanism is not thoroughly elucidated. In this study, we firstly investigated the anti-VM activity of NCTD as a VM inhibitor for GBCs and its underlying mechanisms. METHODS: In vitro and in vivo experiments to determine the effects of NCTD on proliferation, invasion, migration, VM formation, hemodynamic and tumor growth of GBC-SD cells and xenografts were respectively done by proliferation, invasion, migration assays, H&E staining and CD31-PAS double stainings, optic/electron microscopy, tumor assay, and dynamic micro-MRA. Further, immunohistochemistry, immunofluorescence, Western blotting and RT-PCR were respectively used to examine expression of VM signaling-related markers PI3-K, MMP-2, MT1-MMP and Ln-5γ2 in GBC-SD cells and xenografts in vitro and in vivo. RESULTS: After treatment with NCTD, proliferation, invasion, migration of GBC-SD cells were inhibited; GBC-SD cells and xenografts were unable to form VM-like structures; tumor center-VM region of the xenografts exhibited a decreased signal in intensity; then cell or xenograft growth was inhibited. Whereas all of untreated GBC-SD cells and xenografts formed VM-like structures with the same conditions; the xenograft center-VM region exhibited a gradually increased signal; and facilitated cell or xenograft growth. Furthermore, expression of MMP-2 and MT1-MMP products from sections/supernates of 3-D matrices and the xenografts, and expression of PI3-K, MMP-2, MM1-MMP and Ln-5γ2 proteins/mRNAs of the xenografts were all decreased in NCTD or TIMP-2 group; (all P < 0.01, vs. control group); NCTD down-regulated expression of these VM signaling-related markers in vitro and in vivo. CONCLUSIONS: NCTD inhibited tumor growth and VM of human GBCs in vitro and in vivo by suppression of the PI3-K/MMPs/Ln-5γ2 signaling pathway. It is firstly concluded that NCTD may be a potential anti-VM agent for human GBCs.

Norcantharidin inhibits growth of human gallbladder carcinoma xenografted tumors in nude mice by inducing apoptosis and blocking the cell cycle in vivo.

BACKGROUND: Gallbladder carcinoma, a lethal malignant neoplasm with poor prognosis, has dismal results of surgical resection and chemoradiotherapy. We previously reported that norcantharidin (NCTD) is useful against growth, proliferation, and invasion of human gallbladder carcinoma GBC-SD cells in vitro. In this study, we further studied the inhibitory effect of NCTD on the growth of xenografted tumors of human gallbladder carcinoma in nude mice in vivo and the underlying mechanisms. METHODS: The tumor xenograft model of human gallbladder carcinoma in nude mice in vivo was established with subcutaneous GBC-SD cells. The experimental mice were randomly divided into control, 5-FU, NCTD, and NCTD+5-FU groups which were given different treatments. Tumor growth in terms of size, growth curve, and inhibitory rate was evaluated. Cell cycle, apoptosis, and morphological changes of the xenografted tumors were assessed by flow cytometry and light/electron microscopy. The expression of the cell cycle-related proteins cyclin-D1 and p27 as well as the apoptosis-related proteins Bcl-2, Bax, and survivin were determined by the streptavidin-biotin complex (SABC) method and RT-PCR. RESULTS: NCTD inhibited the growth of the xenografted tumors in a dose- and time-dependent manner. Tumor volume decreased (5.61+/-0.39 vs. 9.78+/-0.61 cm3, P=0.000) with an increased tumor inhibitory rate (42.63% vs. 0%, P=0.012) in the NTCD group compared with the control group. The apoptosis rate increased (15.08+/-1.49% vs. 5.49+/-0.59%, P=0.0001) along with a decreased percentage of cells in S phase (43.47+/-2.83% vs. 69.85+/-1.96%, P=0.0001) in the NTCD group compared with the control group. The morphological changes of apoptosis such as nuclear shrinkage, chromatin aggregation, chromosome condensation, and typical apoptosis bodies in the xenografted tumor cells induced by NCTD were observed by light and electron microscopy. The expression of cyclin-D1, Bcl-2 and survivin proteins/mRNAs decreased significantly, with increased expression of p27 and Bax proteins/mRNAs in the NCTD group compared with the control group. CONCLUSION: NCTD inhibits the growth of xenografted tumors of human gallbladder carcinoma in nude mice by inducing apoptosis and blocking the cell cycle in vivo.

Inhibitory effect of norcantharidin on the growth of human gallbladder carcinoma GBC-SD cells in vitro.

BACKGROUND: Gallbladder carcinoma is a lethal malignant neoplasm with dismal surgical results. Unfortunately, the adjuvant therapies for gallbladder carcinoma such as chemotherapy and radiotherapy are also disappointing. We reported that norcantharidin (NCTD), a demethylated form of cantharidin, which is an active ingredient of the Chinese medicine Mylabris, was used against human gallbladder carcinoma GBC-SD cells. In the present study, we further studied the mechanism underlying the inhibitory effect of NCTD on growth of human gallbladder carcinoma GBC-SD cells in vitro. METHODS: Human gallbladder carcinoma GBC-SD cells were grown in cell culture and divided into a NCTD group and a control group. The inhibitory effect of NCTD on growth of GBC-SD cells was investigated by evaluation of proliferation, cell cycle, apoptosis and morphological changes of the cells. Cell proliferation was assessed by tetrazolium-based colorimetric assay. The induction of cell cycle arrest and apoptosis was measured by flow cytometry. The morphological changes of the cells were observed by light- and electron-microscopy. To elucidate the anticancer mechanism of NCTD, expression of the proliferation-related gene proteins PCNA, Ki-67, cyclin-D1 and p27 and the apoptosis-related gene proteins Bcl-2, Bax and Survivin were determined by the streptavidin-biotin complex method and RT-PCR. RESULTS: NCTD inhibited the proliferation of GBC-SD cells in a dose- and time-dependent manner, with an IC50 of 56.18 microg/ml at 48 hours. The flow cytometric profiles revealed that NCTD (at the IC50 for 48 hours) significantly increased the proportion of cells in G2/M phase and significantly decreased the proportion of cells in S phase, with a significantly increased rate of cell apoptosis. After treatment with the 48-hour IC50 dose of NCTD, cell shrinkage, vacuolar cytoplasm, membrane budding, karyorrhexis, karyolysis, chromosome condensation and chromatin aggregation in some GBC-SD cells were observed by light-microscopy; decreased microvilli, Golgiosome atrophy, mitochondrial swelling, nuclear shrinkage, chromosome condensation and typical apoptosis bodies were seen by electron-microscopy, and the morphological changes of apoptosis occurred in GBC-SD cells. The expression of PCNA, Ki-67 and Bcl-2 proteins decreased significantly; the Pix or relative levels of PCNA mRNA, cyclin-D1 mRNA, Bcl-2 mRNA and Survivin mRNA decreased significantly, whereas the Pix or relative levels of p27 mRNA and Bax mRNA increased significantly. CONCLUSIONS: NCTD inhibits the growth of human gallbladder carcinoma GBC-SD cells in vitro. Its anticancer mechanism may correlate with inhibition of cell proliferation, arrest of the cell cycle, blockage of DNA synthesis, influence on cell metabolism, induction of cell apoptosis and influence on expression of the proliferation-related genes PCNA, Ki-67, cyclin-D1 and p27, and the apoptosis-related genes Bcl-2, Bax and Survivin in human gallbladder carcinoma GBC-SD cells.

[Anti-tumor mechanism of norcantharidin for the implanted tumors of human gallbladder carcinoma in nude mice in vivo].

OBJECTIVE: To explore the anti-tumor mechanism of norcantharidin (NCTD) for the implanted tumors of human gallbladder carcinoma in nude mice in vivo. METHODS: Animal model of implanted tumors of human gallbladder carcinoma in nude mice was established. Mice were randomly divided into control, 5-FU, NCTD and NCTD + 5-FU groups and were taken different treatment. The expressions of PCNA, Ki-67, cyclin D1, p27, Bcl-2, Bax, Survivin, nm23/nm23-H1, MMP2 and TIMP2 proteins or genes in each tissue section of every group were determined by immunohistochemistry and RT-PCR. RESULTS: (1) On proliferation-related gene proteins, the expression of PCNA, Ki-67, cyclin D1 was significantly decreased, with significantly increased expression of p27 protein, in paraffin sections of NCTD group when compared with control group (P < 0.05); The expression of PCNA mRNA, cyclin D1 mRNA was decreased, with significantly increased expression of p27 mRNA in NCTD group. (2) On apoptosis-related gene proteins, the expression of Bcl-2 was significantly decreased in paraffin sections of NCTD group when compared with control group (P < 0.05); The expression of Bcl-2 mRNA, Survivin mRNA was significantly decreased, with significantly increased expression of Bax mRNA in NCTD group. (3) There was significant difference on invasion around tumor and lung metastasis in NCTD group when compared with control group (P < 0.01). On metastasis-related gene proteins, the expression of nm23 and TIMP2 was significantly increased, with significantly decreased expression of MMP2 in paraffin sections of NCTD group when compared with control group (P < 0.05); The expression of nm23-H1 mRNA, TIMP2 mRNA was significantly increased, with significantly decreased expression of MMP2 mRNA in NCTD group. CONCLUSIONS: The anti-tumor mechanism of NCTD for human gallbladder carcinoma in nude mice might correlated with inhibition of cell proliferation, blockage of cell cycle, induction of cell apoptosis, reducing of cell motility and invasive capability, alteration of the expression of proliferation-, apoptosis- and metastasis-related gene proteins such as PCNA, Ki-67, cyclin D1, p27, Bcl-2, Bax, Survivin, nm23, MMP2 and TIMP2.

[Effects of norcantharidin on angiogenesis of human gallbladder carcinoma and its anti-angiogenic mechanisms].

OBJECTIVE: To investigate the effects of norcantharidin (NCTD) on angiogenesis of human gallbladder carcinoma and its anti-angiogenic mechanisms. METHODS: Human gallbladder carcinoma cells of the line GBC-SD were cultured. BALB/c nude mice were inoculated subcutaneously with the GBC-SD cells and then randomly divided into 6 groups: NCTD group, injected intraperitoneally with 1/5 of the LD(50) of NCTD twice a week for 6 weeks; 5-fluorouracil (5-FU) group, injected intraperitoneally with 1/5 of the LD(50) of 5-FU twice a week for 6 weeks; endostatin (ES) group, intraperitoneally with ES; NCTD + 5-FU group, injected intraperitoneally with 1/5 of the LD(50) of NCTD and 1/5 of the LD(50) of 5-FU twice a week for 6 weeks; NCTD + ES group, injected intraperitoneally with 1/5 of the LD(50) of NCTD and ES twice a week for 6 weeks; and normal saline (NS) group (control group), injected with NS. The mice were killed in the 7th week. The tumors were taken out to measure their volumes and undergo microscopy. SABC method of immunohistochemistry was used to measure the microvessel density (MVD) and the protein expression of the angiogenesis-related factors: proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), angiopoietin (Ang)-2, thrombospondin (TSP), and tissue inhibitor of metalloprotease (TIMP)(2). Suspension of single tumor cell was prepared to examine the cell apoptosis by flow cytometry. RT-PCR was used to examine the mRNA expression of PCNA, VEGF, Ang-2, TSP, and TIMP2. RESULTS: (1) The MVD of the NCTD group was 4.12 +/- 1.4, significantly lower than those of the 5-FU group (15.8 +/- 5.9) and control group (17.6 +/- 3.2) (both P < 0.01), but not significantly different from those of the NCTD + 5-FU group (3.8 +/- 1.7), ES group (4.5 +/- 2.1), and NCTD + ES group (2.9 +/- 1.5) (all P > 0.05). The mice treated with NCTD showed significantly smaller tumor volume, lower PCNA protein expression, higher apoptotic rate, and higher PCNA/apoptosis ratio (P < 0.05 or P < 0.01), and significant correlation between MVD and tumor volume and between MVD and PCNA/apoptosis ratio (both P < 0.05). (2) The protein expression of VEGF and of Ang-2 of the NCTD group were both significantly lower than those of the control and 5-FU groups (all P < 0.01), however, not significantly different from those of the ES, NCTD + 5-FU, and NCTD + ES groups; and the protein expression of TSP and of TIMP2 of the NCTD group were both significantly higher than those of the control and 5-FU groups (all P < 0.01), however, not significantly different from those of the ES, NCTD + 5-FU, and NCTD + ES groups. MVD was positively correlated with VEGF and Ang-2 expression and negatively correlated with the expression of TSP and TIMP2 (all P < 0.05). (3) In comparison with the control group, the mRNA expression of VEGF and of Ang-2 of the tumor cells of the NCTD group were both significantly lower and the mRNA expression of TIMP2 was significantly higher. CONCLUSION: NCTD down-regulates the expression of the angiogenic factors, such as VEF|GF and Ang-2, and up-regulates the expression of the anti-angiogenic factors, such as TDP and TIMP2, thus inhibiting the angiogenesis in tumor, such as human gallbladder carcinoma, and further inhibiting the growth of tumor.

Effect of norcantharidin on proliferation and invasion of human gallbladder carcinoma GBC-SD cells.

AIM: To investigate the effect of norcantharidin on proliferation and invasion of human gallbladder carcinoma GBC-SD cells in vitro and its anticancer mechanism. METHODS: Human gallbladder carcinoma GBC-SD cells were cultured by cell culture technique. The growth and the invasiveness of GBC-SD cells in vitro were evaluated by the tetrazolium-based colorimetric assay and by the Matrigel experiment and the crossing-river test. Expression of PCNA, Ki-67, MMP2 and TIMP2 proteins of GBC-SD cells was determined by streptavidin-biotin complex method. RESULTS: In vitro norcantharidin inhibited the growth and proliferation of GBC-SD cells in a dose- and time-dependent manner, with the IC50 value of 56.18 microg/mL at 48 h. Norcantharidin began to inhibit the invasion of GBC-SD cells at the concentration of 5 microg/mL, and the invasive action of GBC-SD cells was inhibited completely and their crossing-river time was prolonged significantly at 40 microg/mL. After treatment with norcantharidin, the expression of PCNA, Ki-67, and MMP2 was significantly decreased. With the increase in TIMP2 expression, the MMP2 to TIMP2 ratio was decreased significantly (P<0.05). CONCLUSION: Norcantharidin inhibits the proliferation and growth of human gallbladder carcinoma cells in vitro at relatively low concentrations by inhibiting PCNA and Ki-67 expression. Its anti-invasive activity may be the result of decrease in MMP2 to TIMP2 ratio and reduced cell motility.

Influence of norcantharidin on proliferation, proliferation-related gene proteins proliferating cell nuclear antigen and Ki-67 of human gallbladder carcinoma GBC-SD cells.

BACKGROUND: Gallbladder carcinoma is a highly lethal and aggressive disease with early metastasis, strong invasion and poor prognosis. Most patients with this disease are at the advanced and un-resectable stage and should be considered for palliative treatment such as chemotherapy and radiotherapy. Unfortunately, reports of chemotherapy and radiotherapy for gallbladder carcinoma are disappointing. We investigated the influence of norcantharidin (NCTD) on proliferation, proliferation-related gene proteins PCNA and Ki-67 of human gallbladder carcinoma GBC-SD cells in vitro. METHODS: GBC-SD cell lines of human gallbladder carcinoma were cultured by the cell culture technique. The experiment was divided into NCTD group and control group. The tetrazolium-based colorimetric assay was used to evaluate cell growth. The streptavidin-biotin complex method was used to determine the expressions of proliferation-related gene proteins PCNA and Ki-67 of human gallbladder carcinoma GBC-SD cells. RESULTS: NCTD inhibited the growth and proliferation of GBC-SD cells from 10 mg/L or after 6 hours in a dose-and time-dependent manner, with the IC50 value of 56.18 microg/ml at 48 hours. After treatment with NCTD, the expression of PCNA (0.932+/-0.031 vs. 0.318+/-0.023, P<0.001) and Ki-67 (0.964+/-0.092 vs. 0.297+/-0.018, P<0.001) proteins were decreased significantly. CONCLUSION: NCTD inhibits the proliferation of human gallbladder carcinoma GBC-SD cells in vitro and the expression of their proliferation-related gene proteins PCNA and Ki-67.

[The in vitro effect of norcantharidin on proliferation and invasion of human gallbladder carcinoma GBC-SD cells and its mechanism].

OBJECTIVE: To study the effect and mechanism of action of norcantharidin on proliferation and invasion of GBC-SD cells. METHODS: GBC-SD cells of human gallbladder carcinoma were cultured by cell culture technique. The tetrazolium-based colorimetric assay was used to evaluate cell growth. The Matrigel experiment and the crossing-river test were used to examine the invasiveness of GBC-SD cells. Expression of MMP(2), TIMP(2), PCNA and Ki-67 proteins of GBC-SD cells was determined by streptavidin-biotin complex method. RESULTS: Norcantharidin inhibited the growth and proliferation of GBC-SD cells in a dose and time dependent manner, with an IC(50) value of 56.18 micro g/ml at 48 h. The Matrigel experiment showed that norcantharidin began to inhibit the in vitro invasion of GBC-SD cells at the concentration of 5 micro g/ml. At 40 micro g/ml, the invasive action of GBC-SD cells was inhibited completely and their crossing-river time was prolonged significantly. After treatment with norcantharidin, the expression of PCNA, Ki-67, MMP(2) was significantly decreased. With the increase in TIMP(2) expression, the MMP(2) to TIMP(2) ratio was decreased significantly (P < 0.05). CONCLUSION: Norcantharidin inhibits the in vitro proliferation and growth of human gallbladder carcinoma cells at relatively low concentrations by inhibiting PCNA and Ki-67 expression. Its anti-invasive activity may be the results of decrease in MMP(2) to TIMP(2) ratio and reduced cell motility.