Dynamic Gardner cross-over in a simple glass.

The criticality of the jamming transition responsible for amorphous solidification has been theoretically linked to the marginal stability of a thermodynamic Gardner phase. While the critical exponents of jamming appear independent of the preparation history, the pertinence of Gardner physics far from equilibrium is an open question. To fill this gap, we numerically study the nonequilibrium dynamics of hard disks compressed toward the jamming transition using a broad variety of protocols. We show that dynamic signatures of Gardner physics can be disentangled from the aging relaxation dynamics. We thus define a generic dynamic Gardner cross-over regardless of the history. Our results show that the jamming transition is always accessed by exploring increasingly complex landscape, resulting in anomalous microscopic relaxation dynamics that remains to be understood theoretically.

Controlled generation of self-sustained oscillations in complex artificial neural networks.

Spatially distinct, self-sustained oscillations in artificial neural networks are fundamental to information encoding, storage, and processing in these systems. Here, we develop a method to induce a large variety of self-sustained oscillatory patterns in artificial neural networks and a controlling strategy to switch between different patterns. The basic principle is that, given a complex network, one can find a set of nodes-the minimum feedback vertex set (mFVS), whose removal or inhibition will result in a tree-like network without any loop structure. Reintroducing a few or even a single mFVS node into the tree-like artificial neural network can recover one or a few of the loops and lead to self-sustained oscillation patterns based on these loops. Reactivating various mFVS nodes or their combinations can then generate a large number of distinct neuronal firing patterns with a broad distribution of the oscillation period. When the system is near a critical state, chaos can arise, providing a natural platform for pattern switching with remarkable flexibility. With mFVS guided control, complex networks of artificial neurons can thus be exploited as potential prototypes for local, analog type of processing paradigms.

[Expression of TGF-ß in bladder neck contracture after transurethral enucleation and resection of the prostate].

OBJECTIVE: To explore the role of transforming growth factor-ß (TGF-ß) in bladder neck contracture (BNC) after transurethral enucleation and resection of the prostate (TUERP). METHODS: This study included 300 BPH patients undergoing TUERP, aged 51－89 (69.19 ± 8.43) years, with the prostate volume of 14.4－355.8 (63.18 ± 47.63) ml and preoperative IPSS of 15－35 (26.07 ± 5.9), QOL score of 3－6 (4.43 ± 0.67), PSA content of 0.17－23.16 (2.94 ± 3.77) ug/L, urinary leukocyte increase in 50 cases, post-void residual urine volume (PVR) of 0－440 (83.53 ± 86.85) ml, and maximum urinary flow rate (Qmax) of 2.3－14.5 (7.77 ± 3.47) ml/s. During TUERP, we collected the tissues from the bladder neck at 5 and 7 o'clock as well as the BPH tissue and the tissue from the residual prostate for HE staining, immunohistochemistry (the SP method) and examination of the infiltration degree of inflammatory cells and expressions of TGF-ß1 and TGF-ß3. During the 6－24 months follow-up, 6 of the patients were confirmed with BNC based on the clinical symptoms and the results of uroflowmetry and cystoscopy, and underwent transurethral bladder neck incision and detection of the expressions of TGF-ß1 and TGF-ß3 in the bladder neck tissue with BNC. RESULTS: The bladder neck tissue without BNC was mainly composed of smooth muscle and fibrous tissues with local infiltration of inflammatory cells, and the residual prostate tissue primarily comprised fibrous and muscle tissues, mixed with a little prostatic epithelial tissue. The bladder neck tissue with BNC, compared with that harvested during the initial TUERP, exhibited significantly increased expression of TGF-ß1 (ï¼»68.20 ± 10.88ï¼½% vs ï¼»36.14 ± 7.62ï¼½%, P < 0.05), decreased expression of TGF-ß3 (ï¼»8.55 ± 4.73ï¼½% vs ï¼»20.77 ± 8.69ï¼½%, P < 0.05), and enhanced infiltration of inflammatory cells (P < 0.05). The bladder neck tissue without BNC, in comparison with the BPH tissue, showed dramatically up-regulated expressions of TGF-ß1 (ï¼»27.05 ± 8.21ï¼½% vs ï¼»1.61 ± 0.69ï¼½%, P < 0.001) and TGF-ß3 (ï¼»14.09 ± 4.19ï¼½% vs ï¼»0.32 ± 0.11ï¼½%, P < 0.001) and increased infiltration of inflammatory cells (P < 0.05). CONCLUSIONS: After TUERP, the expression of TGF-ß1 is increased, that of TGF-ß3 decreased and the infiltration of inflammatory cells enhanced in the bladder neck tissue with BNC, which suggests that BNC may be related to the expression of TGF-ß and that BNC after TUERP could be prevented by regulating the expression of TGF-ß.

Covering Problems and Core Percolations on Hypergraphs.

We introduce two generalizations of core percolation in graphs to hypergraphs, related to the minimum hyperedge cover problem and the minimum vertex cover problem on hypergraphs, respectively. We offer analytical solutions of these two core percolations for uncorrelated random hypergraphs whose vertex degree and hyperedge cardinality distributions are arbitrary but have nondiverging moments. We find that for several real-world hypergraphs their two cores tend to be much smaller than those of their null models, suggesting that covering problems in those real-world hypergraphs can actually be solved in polynomial time.

DCA for genome-wide epistasis analysis: the statistical genetics perspective.

Direct coupling analysis (DCA) is a now widely used method to leverage statistical information from many similar biological systems to draw meaningful conclusions on each system separately. DCA has been applied with great success to sequences of homologous proteins, and also more recently to whole-genome population-wide sequencing data. We here argue that the use of DCA on the genome scale is contingent on fundamental issues of population genetics. DCA can be expected to yield meaningful results when a population is in the quasi-linkage equilibrium (QLE) phase studied by Kimura and others, but not, for instance, in a phase of clonal competition. We discuss how the exponential (Potts model) distributions emerge in QLE, and compare couplings to correlations obtained in a study of about 3000 genomes of the human pathogen Streptococcus pneumoniae.

Kinked Entropy and Discontinuous Microcanonical Spontaneous Symmetry Breaking.

Spontaneous symmetry breaking (SSB) in statistical physics is a macroscopic collective phenomenon. For the paradigmatic Q-state Potts model it means a transition from the disordered color-symmetric phase to an ordered phase in which one color dominates. Existing mean field theories imply that SSB in the microcanonical statistical ensemble (with energy being the control parameter) should be a continuous process. Here we study microcanonical SSB on the random-graph Potts model and discover that the entropy is a kinked function of energy. This kink leads to a discontinuous phase transition at certain energy density value, characterized by a jump in the density of the dominant color and a jump in the microcanonical temperature. This discontinuous SSB in random graphs is confirmed by microcanonical Monte Carlo simulations, and it is also observed in bond-diluted finite-size lattice systems.

Entropy Inflection and Invisible Low-Energy States: Defensive Alliance Example.

Lower temperature leads to a higher probability of visiting low-energy states. This intuitive belief underlies most physics-inspired strategies for addressing hard optimization problems. For instance, the popular simulated annealing (SA) dynamics is expected to approach a ground state if the temperature is lowered appropriately. Here, we demonstrate that this belief is not always justified. Specifically, we employ the cavity method to analyze the minimum strong defensive alliance problem and discover a bifurcation in the solution space, induced by an inflection point in the entropy-energy profile. While easily accessible configurations are associated with the lower-free-energy branch, the low-energy configurations are associated with the higher-free-energy branch within the same temperature range. There is a discontinuous phase transition between the high-energy configurations and the ground states, which generally cannot be followed by SA. We introduce an energy-clamping strategy to obtain superior solutions by following the higher-free-energy branch, overcoming the limitations of SA.

Co-emergence of multi-scale cortical activities of irregular firing, oscillations and avalanches achieves cost-efficient information capacity.

The brain is highly energy consuming, therefore is under strong selective pressure to achieve cost-efficiency in both cortical connectivities and activities. However, cost-efficiency as a design principle for cortical activities has been rarely studied. Especially it is not clear how cost-efficiency is related to ubiquitously observed multi-scale properties: irregular firing, oscillations and neuronal avalanches. Here we demonstrate that these prominent properties can be simultaneously observed in a generic, biologically plausible neural circuit model that captures excitation-inhibition balance and realistic dynamics of synaptic conductance. Their co-emergence achieves minimal energy cost as well as maximal energy efficiency on information capacity, when neuronal firing are coordinated and shaped by moderate synchrony to reduce otherwise redundant spikes, and the dynamical clusterings are maintained in the form of neuronal avalanches. Such cost-efficient neural dynamics can be employed as a foundation for further efficient information processing under energy constraint.

[Finasteride inhibits microvascular density and VEGF expression in the seminal vesicle of rats].

OBJECTIVE: To investigate the effect of finasteride on the microvascular density (MVD) and the expression of the vascular endothelial growth factor (VEGF) in the seminal vesicle of rats. METHODS: Forty male SD rats were randomly and equally divided into groups A, B, C and D, those in groups A and B fed with normal saline as the control and those in C and D with finasteride at 40 mg per kg of the body weight per day, A and C for 14 days and B and D for 28 days. Then the seminal vesicles of the animals were harvested for HE staining, measurement of MVD, determination of the expressions of CD34 and VEGF by immunohistochemistry, and observation of histomorphological changes in the seminal vesicle. RESULTS: The expressions of CD34 in groups C and D were decreased by 6.7% and 15.8% as compared with those in A and B (P<0.01), and that in group D decreased by 9.3% in comparison with that in C (P<0.01). The expression indexes of VEGF in groups C and D were decreased by 6.9% and 14.1% as compared with those in A and B (P<0.01), and that in group D decreased by 9.0% in comparison with that in C (P<0.01). CONCLUSIONS: Finasteride can inhibit the expression of VEGF in the seminal vesicle tissue of the rat and hence suppress the angiogenesis of microvessels of the seminal vesicle.

The bulk and the tail of minimal absent words in genome sequences.

Minimal absent words (MAW) of a genomic sequence are subsequences that are absent themselves but the subwords of which are all present in the sequence. The characteristic distribution of genomic MAWs as a function of their length has been observed to be qualitatively similar for all living organisms, the bulk being rather short, and only relatively few being long. It has been an open issue whether the reason behind this phenomenon is statistical or reflects a biological mechanism, and what biological information is contained in absent words. In this work we demonstrate that the bulk can be described by a probabilistic model of sampling words from random sequences, while the tail of long MAWs is of biological origin. We introduce the concept of a core of a MAW, which are sequences present in the genome and closest to a given MAW. We show that in E. faecalis, E. coli and yeast the cores of the longest MAWs, which exist in two or more copies, are located in highly conserved regions the most prominent example being ribosomal RNAs. We also show that while the distribution of the cores of long MAWs is roughly uniform over these genomes on a coarse-grained level, on a more detailed level it is strongly enhanced in 3' untranslated regions (UTRs) and, to a lesser extent, also in 5' UTRs. This indicates that MAWs and associated MAW cores correspond to fine-tuned evolutionary relationships, and suggest that they can be more widely used as markers for genomic complexity.

[SERS Enhancement Factor Analysis and Experiment of Carbon Nanotube Arrays Coated by Ag Nanoparticles].

To intuitive and accurate quantitatively analyze Raman enhancement of surface enhanced Raman scattering substrate structure, three-dimensional composite structure of silver nanoparticles modified vertically aligned carbon nanotube array is produced by magnetron sputtering and thermal annealing process; Relevant experiments using Rhodamine 6G (R6G) solution as the molecular probes are conducted to analyze surface enhanced Raman enhancement factor (EF), combining with confocal Raman microscopy systems. The result of scanning electron microscopy (SEM) shows that a large number of silver nanoparticles are attached onto the tips and sidewalls of the ordered carbon nanotubes array uniformly. EF of the sample which was produced 30 min annealing time and 450 degrees C annealing temperature evaluates to 2.2 x 10(3), and the reasons for the low EF are analyzed: on the one hand, thickness of silver film sputtered on vertically aligned carbon nanotube array is non-uniform, leading to distribution of silver nanoparticles is uneven after annealing, so that the value of sample roughness is too large, EF value is low; on the other hand, the excitation light source is not the advantage wavelength of silver nanoparticles in the experiments.

Osteopontin promoter polymorphisms at locus -443 significantly affect the metastasis and prognosis of human hepatocellular carcinoma.

UNLABELLED: Osteopontin (OPN) plays a crucial role in hepatocellular carcinoma (HCC) metastasis. However, little is known about the impact of OPN polymorphisms on cancer progression. In this study, we first identified the single nucleotide polymorphisms (SNPs) in the OPN promoter region by direct sequencing in 30 HCCs, and then evaluated the prognostic values of the selected ones in two large cohorts of 826 HCC patients. The identified SNPs were functionally analyzed using in vitro and in vivo assays and their correlations with OPN levels were also evaluated. Only SNP at locus -443 and their related haplotypes (Ht2: -1748A/-616G/-443T/-155* [*indicates base deletion]; Ht3: -1748A/-616G/-443C/-155*) were significantly associated with overall survival (OS) and time to recurrence (TTR). The patients with the -443TT/TC genotype or Ht2 had a shorter OS and TTR compared with those with -443CC genotype or Ht3. This was further confirmed in the validation cohort. Moreover, this correlation remained significant in patients with small HCCs (≤5 cm). Multivariate analyses indicated that the prognostic performance of the -443 genotypes (OS, P=0.031; TTR, P=0.005) and their related haplotypes (OS, P=0.002; TTR, P=0.001) was independent of other clinicopathological factors. The Ht2 and -443TT genotype could significantly increase the promoter transcriptional activity and expression level of OPN compared with the Ht3 or -443CC genotype, and lead to an obvious increase in both in vitro invasion and in vivo tumor growth and lung metastasis of HCC cells (P<0.05). CONCLUSION: The genetic variation at locus -443 of the OPN promoter plays important roles in the regulation of OPN expression and cancer progression of HCCs, which is a novel determinant and target for HCC metastasis and prognosis.

MicroRNA-26a suppresses tumor growth and metastasis of human hepatocellular carcinoma by targeting interleukin-6-Stat3 pathway.

UNLABELLED: Down-regulation of microRNA-26a (miR-26a) is associated with poor prognosis of hepatocellular carcinoma (HCC), but its functional mechanism in HCC remains unclear. In this study, we investigated the roles of miR-26a in tumor growth and metastasis of HCC and found that miR-26a was frequently down-regulated in HCC tissues. Down-regulation of miR-26a correlated with HCC recurrence and metastasis. Through gain- and loss-of-function studies, miR-26a was demonstrated to significantly inhibit in vitro cell proliferation, migration, and invasion. In addition, miR-26a induced G1 arrest and promoted apoptosis of HCC cells. Importantly, miR-26a suppressed in vivo tumor growth and metastasis in nude mice models bearing human HCC. Interleukin-6 (IL-6) was identified as a target of miR-26a. Knockdown of IL-6 induced effects on HCC cells similar to those induced by miR-26a. In contrast, IL-6 treatment abrogated the effects induced by miR-26a up-regulation. Moreover, miR-26a dramatically suppressed expression of signal transducer and activator of transcription 3 (Stat3) target genes, including Bcl-2, Mcl-1, cyclin D1, and MMP2. IL-6 treatment antagonized this effect, while knockdown of IL-6 by IL-6 short hairpin RNA (shIL-6) induced inhibitory effects on the expression of p-Stat3 and its main target genes, similar to miR-26a. The messenger RNA and protein levels of IL-6 inversely correlated with miR-26a in HCCs. Patients with high miR-26a or low IL-6 in HCC tissues had a better prognosis with longer overall survival (OS) and time to recurrence (TTR). In multivariate analysis, miR-26a, IL-6, and their combination were demonstrated to be independent prognostic indicators for OS and TTR of HCC patients. CONCLUSION: miR-26a could suppress tumor growth and metastasis of HCC through IL-6-Stat3 signaling and is a novel prognostic marker and therapeutic target for HCC.

[Transurethral seminal vesiculoscopy combined with finasteride for recurrent hematospermia].

OBJECTIVE: To evaluate the clinical effectiveness of transurethral seminal vesiculoscopy (TUSV) combined with finasteride in the treatment of recurrent hemospermia. METHODS: This study included 32 patients with recurrent hematospermia, with the disease course of 3 months to 4 years. After administration of finasteride at 5 mg/d for 2 weeks, the patients underwent TUSV for both exploration of the causes and treatment, followed by medication with finasteride at the same dose for another 2 weeks. Postoperative follow-up was conducted for observation of the outcomes and complications. RESULTS: TUSV was successfully accomplished in all the 32 cases, which revealed 16 cases of seminal vesiculitis, 10 seminal calculi, 1 seminal vesicle cyst, 2 seminal vesicle polyps, and 3 seminal vesicle abscess. The operative time was 20 to 51 (31.0 +/- 5.2) minutes. Postoperative complications included 1 case of acute epididymitis and 3 cases of breast discomfort within the first 4 weeks. No incontinence, urethral stricture, rectal injury, retrograde ejaculation, and sexual dysfunction occurred postoperatively. All the patients but 1 were followed up for 6 months to 2 years. Twenty-nine of the cases were cured, and 2 experienced recurrence. CONCLUSION: Transurethral seminal vesiculoscopy combined with finasteride is safe and effective for the treatment of recurrent hemospermia.

Postoperative serum osteopontin level is a novel monitor for treatment response and tumor recurrence after resection of hepatitis B-related hepatocellular carcinoma.

BACKGROUND: Presurgery serum osteopontin (OPN) level has been demonstrated to correlate to tumor recurrence and survival of hepatocellular carcinoma (HCC) patients. This study investigated the postoperative dynamic changes of serum OPN level and its clinical significance in HCC patients. METHODS: Presurgery serum OPN levels were measured by enzyme-linked immunosorbent assay in cohort A of 179 HCC patients and were compared with the multiple controls including different kinds of liver diseases and healthy individuals. In cohort B of 110 patients with resectable HCCs, besides preoperative assays, serum OPN was monitored at 1 week, 1, and ≥2 months after operation. RESULTS: The baseline presurgery serum OPN of HCC patients was significantly higher than that of the patients with the other kinds of liver diseases (p < 0.0001). The prognostic values of presurgery serum OPN level in HCC patients were further confirmed. The postsurgery OPN levels were significantly elevated within 1 week after HCC resection, then decreased at 1 month and reached the nadir later than 2 months after operations. It increased again at the time of tumor recurrence, then declined after the second removal of recurrent HCCs. Moreover, postoperative OPN in α-fetoprotein-negative and -positive HCC patients had the same changing pattern; it only correlated to liver function and C-reactive protein level. CONCLUSIONS: After a transient fluctuation, serum OPN levels significantly decrease after curative resection of HCCs. Postoperative serum OPN could serve as a surrogate serologic biomarker for monitoring treatment response and tumor recurrence after HCC resection, including α-fetoprotein-negative ones.

Downregulation of HTPAP transcript variant 1 correlates with tumor metastasis and poor survival in patients with hepatocellular carcinoma.

Our previous study has identified HTPAP as a novel metastasis suppressor from chromosome 8p which is often deleted in metastatic HCC. We sought to further evaluate the expression levels of transcript variants of HTPAP (HTPAP-1, HTPAP-2 and HTPAP-3) in 67 HCC tumor tissues and 11 normal liver tissues by RT-PCR with specific TaqMan probes and primer sets, and explore their association with HCC metastasis and survival. We found that the expression levels of three HTPAP transcript variants were quite different in HCCs. Only HTPAP-1 was found to be significantly associated with HCC metastasis (P=0.00053), overall survival (P=0.0023) and time to recurrence (P=0.010) of HCC. Patients with a lower expression of HTPAP-1 were inclined to accompany intrahepatic metastases and tumor thrombi (P<0.05) and had a poor prognosis. In vitro, three fusion pEGFP-N1 vectors encoding HTPAP-1, HTPAP-2 and HTPAP-3 were introduced into HCC cells respectively to track HTPAPs' expressions and identify their function. We found overexpression of HTPAP-1 conferred HCC cells reduced ability of invasion without significant impact on cell proliferation, and also displayed a distinct cell location on cell membrane and in cytoplasm, which were different from two other variants. Consequently, HTPAP-1 may be the transcript of HTPAP to exhibit a suppressive role on HCC metastasis, and can be a prognostic marker for HCC.

Thrombin is a therapeutic target for metastatic osteopontin-positive hepatocellular carcinoma.

UNLABELLED: We previously identified osteopontin (OPN) as a promoter and thus a potential therapeutic target for hepatocellular carcinoma (HCC) metastasis. The serine protease thrombin interacts with OPN and can modify its biological activity. To explore the role of thrombin alone or in conjunction with OPN in HCC, we studied the correlation of thrombin levels to HCC prognosis in patients with various OPN levels, and evaluated the effects of OPN fragments generated by thrombin cleavage on proliferation and adhesion of HCC cells. We found that the thrombin level was strongly associated with the metastatic potential of HCC cell lines, and that thrombin was remarkably overexpressed in HCC tissue compared with adjacent nontumor tissue. In addition, HCC tissue from patients with recurrent disease displayed much higher thrombin levels, particularly in those with elevated OPN levels. Only HCCs with elevated OPN levels had a significant correlation between high thrombin levels and overall survival (OS; P < 0.01), or time to recurrence (TTR; P < 0.0001) of HCC. Multivariate analysis revealed that thrombin was an independent prognostic indicator. In vitro assays demonstrated that thrombin promotes the proliferation and adhesion of OPN+ HCC cells. Furthermore, thrombin activated the focal adhesion kinase (FAK) pathway of OPN+ HCC cells, which was blocked by the inhibition of integrin ß1. CONCLUSION: Thrombin plays an important role in OPN-mediated aggressive phenotype of HCC through activation of integrin ß1-FAK signaling, and is an independent poor prognostic factor for HCC. Thus, thrombin may be a potential therapeutic target to inhibit HCC metastasis in OPN+ patients.

[High expression of thrombin receptor PAR1 in peritumoral liver tissue is associated with poor survival after curative resection of hepatocellular carcinoma in early stage].

OBJECTIVE: To evaluate the relationship between PAR1 (Protease-Activated Receptor 1) expression and the clinicopathologic features and to investigate the prognostic value of PAR1 expression in hepatocellular carcinoma (HCC) in early stage after curative resection. METHODS: Real-time PCR was used to detect PAR1 expression in 41 pairs of tumors and matched peritumoral samples of HCC in early stage. Prognostic value of PAR1 mRNA expression was evaluated. Meanwhile, another 49 tissue paraffin slices of HCC were tested using immunohistochemistry (Envision) and the prognostic value of PAR1 expression and other clinicopathologic factors were evaluated. RESULTS: Peritumoral PAR1 mRNA expression was significantly increased in HCCs from the patients with tumor recurrence as compared with those without recurrence (P < 0.05). Peritumoral PAR1 protein expression was related to tumor differentiation (P < 0.05). Kaplan-Meier analysis showed that Peritumoral PAR1 protein expression was associated with the overall survival (OS) (P < 0.05) of HCC patients and the time to recurrence (TTR) (P < 0.05). The 1, 3 and 5 -year overall survival time and the cumulative recurrence time in the high PAR1 protein expression group were significantly lower as compared to the low PAR1 expression group in the peritumoral liver tissue. CONCLUSIONS: Peritumoral PAR1 expression is closely associated with the prognosis of early stage HCC patients after curable surgery. PAR1 may be involved in thrombin-mediated invasion process and may be used as a prognostic marker for HCC.

[The effect of RhoE on CD44 promoter and the malignant behaviors of colorectal cancer cell].

OBJECTIVE: To study the effect of RhoE on the transcriptional regulation of cd44 and in vivo tumorigenicity of nude mice. METHODS: cd44 promoter was amplified from human embryonic kidney HEK293 cells with PCR and insert into Dual-Luciferase Reporter plasmid pGL3-Basic. After confirmed with sequence analysis, the generated recombinant was transfected into SW480 and LoVo cells to monitor their activity. Colon cancer SW480 and LoVo cells were cotransfected with pGL3-CD44 promoter along with pcDNA3. 1-RhoE and pcDNA3. 1 respectively. SW480 and LoVo cells were stably transfected with pcDNA3. 1-RhoE and the control group and were inoculated into nude mice to observe tumor growth. Immunohistochemistry assay was applied to observe the morphology of tumor cells and the expression of CD44 molecules. RESULTS: The cd44 promoter sequence was amplified correctly, Dual-Luciferase Reporter Assay showed that the constructed reporter gene has promoter activity. The expression of cd44 promoter sequence containing reporter gene in pcDNA3. 1-RhoE expression positive LoVo cells was inhibited; HE staining demonstrated that the pcDNA3. 1-RhoE transfected tumor cells was significantly smaller than that in the control group, and consistent size and shape tumor cells were observed but no tumor giant cells, the corresponding volume of the tumor nuclei were also small. CONCLUSION: RhoE could partially reverse the malignant biological behavior of tumors by inhibiting the transcriptional regulation of cd44 promoter.

[The effect of RhoA and proteasome inhibitor MG132 on angiogenesis in tumors].

OBJECTIVE: To investigate the effect of RhoA to VEGF, HIF-1alpha and MVD (microvascular density) and the effect of MG132 to RhoA. METHODS: The constitutively-active mutant vectors of RhoA (pCEFL-GST-V14RhoA) were transfected into gastric cancer cell line MKN-45 by Lipofectamine 2000, single clones were selected by G418 and identified with western blot. The content of VEGF in the conditioned media was detected by ELISA. Constitutively-active RhoA nude mice models were established and treated with MG132. The effect of RhoA and MG132 on expression of HIF-1alpha, VEGF and CD31 were detected by immunohistochemistry. RESULTS: Cell line of stable-transfected constitutively-active RhoA was established and constitutively-active RhoA could stimulate secretion of VEGF but MG132 inhibited that. Constitutively-active RhoA could obviously induce growth of tumor (P < 0.05), but MG132 inhibited it (P < 0.05). Constitutively-active RhoA could promote protein of HIF-1alpha, VEGF and CD31 but MG132 inhibited the function of RhoA (P < 0.05). CONCLUSION: Our studies indicates that MG132 could affect angiogenesis of tumors through inhibition the regulating function of RhoA on HIF-1alpha, VEGF and CD31.