Extracellular Membrane Vesicles of Escherichia coli Induce Apoptosis of CT26 Colon Carcinoma Cells.

Escherichia coli (E. coli) is commonly utilized as a vehicle for anti-tumor therapy due to its unique tumor-targeting capabilities and ease of engineering modification. To further explore the role of E. coli in tumor treatment, we consider that E. coli outer membrane vesicles (E. coli-OMVs) play a crucial role in the therapeutic process. Firstly, E. coli-OMVs were isolated and partially purified by filtration and ultracentrifugation, and were characterized using techniques such as nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and Western Blot (WB). The obtained extracellular nanoparticles, containing OMVs, were found to inhibited the growth of CT26 tumor in mice, while the expression of Bax protein was increased and the expression of Bcl-2 protein decreased. In vitro experiments showed that E. coli-OMVs entered CT26 cells and inhibited cell proliferation, invasion and migration. In addition, in the presence of E. coli-OMVs, we observed an increase in apoptosis rate and a decrease in the ratio of Bcl-2/Bax. These data indicate that E. coli-OMVs inhibits the growth of CT26 colon cancer by inducing apoptosis of CT26 cells. These findings propose E. coli-OMVs as a promising therapeutic drug for colorectal cancer (CRC), providing robust support for further research in related fields.

[Preparation of bacterial outer membrane vesicles with anti-GPC3 single-chain antibody and identification of their targeting effects on hepatocellular carcinoma].

This study aims to prepare bacterial outer membrane vesicles (OMVs) with anti-glypican-3 (GPC3) single-chain antibody and analyze their targeting effects on Hep G2 hepatocellular carcinoma (HCC) cells and tissue. The recombinant plasmid pET28a-Hbp-hGC 33-scFv was constructed by ligating Hbp-hGC 33-scFv to pET28a. Western blotting was employed to determine the prokaryotic expression of the fusion protein Hbp-hGC 33-scFv, on the basis of which the optimal induction conditions were determined. Hbp-hGC 33-OMVs secreted from the recombinant expressing strains were collected by ultrafiltration concentration and then characterized. The localization of Hbp-hGC 33-scFv in bacteria and Hbp-hGC 33-OMVs was analyzed by immune electron microscopy. The binding of Hbp-hGC 33-scFv to Hep G2 cells was observed by immunofluorescence. The Hep G2 tumor-bearing mouse model was established, and the targeted retention of Hbp-hGC 33-OMVs in the tumor site of mice was observed by a fluorescence imaging system in vivo. The results showed that the actual molecular weight of the fusion protein was 175.3 kDa, and the optimal induction conditions were as follows: OD600=0.5, IPTG added at a final concentration of 0.5 mmol/L, and overnight induction at 16 ℃. The prepared Hbp-hGC 33-OMVs were irregular spherical structures with an average particle size of (112.3±4.6) nm, expressing OmpC, OmpA, and the fusion protein Hbp-hGC 33-scFv. The Hbp-hGC 33-OMVs prepared in this study demonstrated stronger ability of binding to Hep G2 cells than the wild-type OMVs (P=0.008). All the data indicated that Hbp-hGC 33-OMVs with anti-GPC3 single-chain antibody were successfully prepared and could be used for research on the targeted therapy of hepatocellular carcinoma.

The prognostic genes model of breast cancer drug resistance based on single-cell sequencing analysis and transcriptome analysis.

Breast cancer (BC) represents a multifaceted malignancy, with escalating incidence and mortality rates annually. Chemotherapy stands as an indispensable approach for treating breast cancer, yet drug resistance poses a formidable challenge. Through transcriptome data analysis, we have identified two sets of genes exhibiting differential expression in this context. Furthermore, we have confirmed the overlap between these genes and those associated with exosomes, which were subsequently validated in cell lines. The investigation screened the identified genes to determine prognostic markers for BC and utilized them to formulate a prognostic model. The disparities in prognosis and immunity between the high- and low-risk groups were validated using the test dataset. We have discerned different BC subtypes based on the expression levels of prognostic genes in BC samples. Variations in prognosis, immunity, and drug sensitivity among distinct subtypes were examined. Leveraging data from single-cell sequencing and prognostic gene expression, the AUCell algorithm was employed to score individual cell clusters and analyze the pathways implicated in high-scoring groups. Prognostic genes (CCT4, CXCL13, MTDH, PSMD2, and RAB27A) were subsewoquently validated using RT-qPCR. Consequently, we have established a model for predicting prognosis in breast cancer that hinges on drug resistance and ERGs. Furthermore, we have evaluated the prognostic value of this model. The genes identified as prognostic markers can now serve as a reference for precise treatment of this condition.

Melanoma extracellular vesicles inhibit tumor growth and metastasis by stimulating CD8 T cells.

Tumor cell-derived extracellular vesicles (EVs) play a crucial role in mediating immune responses by carrying and presenting tumor antigens. Here, we suggested that melanoma EVs triggered cytotoxic CD8 T cell-mediated inhibition of tumor growth and metastasis. Our results indicated that immunization of mice with melanoma EVs inhibited melanoma growth and metastasis while increasing CD8 T cells and serum interferon γ (IFN-γ) in vivo. In vitro experiments showed that melanoma EV stimulates dendritic cells (DCs) maturation, and mature dendritic cells induce T lymphocyte activation. Thus, tumor cell-derived EVs can generate anti-tumor immunity in a prophylactic setting and may be potential candidates for cell-free tumor vaccines.

Bifidobacterium-derived membrane vesicles inhibit triple-negative breast cancer growth by inducing tumor cell apoptosis.

BACKGROUND: Bacterial outer membrane vesicles have gained increasing attention for its antitumor effect and application in drug delivery. However, the bacterial membrane vesicles (MVs) that are secreted by Gram-positive bacteria are rarely mentioned. Bifidobacterium has a certain anti-tumor effect, but there is a certain risk when injected into human body. Here we investigated the potential of Bifidobacterium-derived membrane vesicles (B-MVs) as therapeutic agents to treat triple-negative breast cancer. METHODS AND RESULTS: Firstly, we discovered that Bifidobacterium can produce B-MVs and isolated them. In vivo, we found that B-MVs can inhibit tumor growth in mice and the mice were in good state. H&E staining displayed extensive apoptotic cells in tumor tissues. Western blotting and immunohistochemistry showed that B-MVs increased the expression of Bax, while decreased the expression of Bcl-2. These results suggested that B-MVs may induce apoptosis of tumor cells in vivo. Furthermore, to further confirm this phenomenon, we conducted experiments in vitro. Hoechst 33,258 staining assay, flow cytometry and western blotting also demonstrated B-MVs promoted cell apoptosis in vitro. CONCLUSIONS: We speculate B-MVs may inhibit tumor growth by inducing tumor cell apoptosis in triple-negative breast cancer, which provided a new direction in the treatment of TNBC.

Dauer larva-derived extracellular vesicles extend the life of Caenorhabditis elegans.

There is growing evidence that extracellular vesicles (EVs) play a functional role in tissue repair and anti-aging by transferring the contents of donor cells to recipient cells. We hypothesized that Dauer (C. elegans), known as "ageless" nematodes, can also secrete extracellular vesicles and influence the lifespan of C. elegans. Here, we isolated EVs of dauer larvae (dauer EVs). Dauer EVs were characterized using transmission electron microscopy, nanoparticle tracking analysis (NTA), and Western blot analysis. Wild-type C. elegans were fed in the presence or absence of dauer EVs and tested for a range of phenotypes, including longevity, mobility and reproductive capacity. Results showed that dauer EVs increased the average lifespan of nematodes by 15.74%, improved mobility, slowed age-related pigmentation as well as body length, and reduced the accumulation of reactive oxygen species and lipids, while not impairing nematode reproductive capacity. These findings suggest that dauer EVs can extend the lifespan of C. elegans as well as the healthy lifespan by reducing ROS accumulation, with potential anti-aging capacity.

Comparative proteomics identify HSP90A, STIP1 and TAGLN-2 in serum extracellular vesicles as potential circulating biomarkers for human adenomyosis.

Extracellular vesicles (EVs) carry specific proteins involved in intercellular communication. EVs with different protein contents are released into circulation in different diseases. Recent studies have identified proteins in adenomyosis (AM)-derived EVs (AMEVs) from blood as biomarkers for this disease. AM is an extension of endometrial tissue into the uterine myometrium. Magnetic resonance imaging (MRI) is the most accurate imaging tool for identifying adenomyosis. Therefore, the present study aimed to investigate the role of EVs in diagnosing AM. In the present study, tissue AMEVs (T-AMEVs) were isolated from lesion homogenates of patients with adenomyosis, and blood AMEVs (B-AMEVs) were isolated from peripheral blood of patients with AM via differential centrifugation and density gradient centrifugation. T-AMEVs and B-AMEVs were characterized by electron microscopy, western blotting and mass spectrometry and analysed using FunRich3.1.3 software. T-AMEVs (average diameter, 150.9±102.2 nm) and B-AMEVs (194.1±66.81 nm) expressed the CD9, CD63 and flotillin-2 EV markers. A total of 211 proteins expressed in T-AMEVs and B-AMEVs overlapped with Vesiclepedia database entries, including 2 epithelial-to-mesenchymal transition (EMT)-associated proteins and 6 invasion-associated proteins. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these 211 proteins were associated with the 'regulation of cell morphogenesis' and 'cytoskeletal organization' terms, as well as the PPAR and HIF-1 signalling pathways, which are related to the proliferation and metastasis of endometrial cells that cannot invade the myometrium under normal circumstances. Among the 211 proteins, HSP90A, STIP1 and TAGLN-2 were expressed in T-AMEVs and B-AMEVs, but not in serum EVs of women without adenomyosis/endometriosis, and these proteins might be the potential biomarkers for adenomyosis. These findings provide insights into the molecular features of adenomyosis and the new candidate biomarkers for diagnosis.

Subgroups of Extracellular Vesicles: Can They Be Defined by "Labels?"

Extracellular vesicles (EVs) are a class of lipid bilayer membranes, containing lipids, nucleic acids (DNA and RNA), proteins, and other substances. They are produced by almost all types of cells and act as signaling intermediaries between cells and/or tissues through different mechanisms involving complex signals. EVs produced by each type of cells are composed of highly heterogeneous and inhomogeneous subgroups with different biological functions. Therefore, in the past few decades, researchers have tried to use different "labels" to define the subgroups of EVs, and explore the differences in them. However, a unified standard for defining the populations of EVs has not yet been established so far. In this study, we review and summarize the use of different "labels" to define subgroups of EVs.

Melanoma-Derived Exosomes Endow Fibroblasts with an Invasive Potential via miR-21 Target Signaling Pathway.

BACKGROUND: Tumor-derived exosomes are messengers that participate in tumor progression. Fibroblasts are associated with the metastasis of cancer depending on their cellular plasticity. We hypothesize that tumor-derived exosomes endow the fibroblasts in tumor microenvironment with invasive phenotype to the benefit of tumor metastasis. MATERIALS AND METHODS: Exosomes derived from B16-F10 cells were identified by nanoparticle tracking analyzer (NTA), dynamic light scattering (DLS), Western blot (WB), and transmission electron microscopy (TEM). Cell invasion and migration assays were performed using the xCELLigence real-time cell analyzer (RTCA). Role of tumor-derived exosomal miR-21 in cell invasion was determined by qPCR. RESULTS: The invasion analysis showed that exosome-treated fibroblast cells had greater invasive capability as compared to untreated fibroblast cells, with the higher expressions of MMP2 and MMP9. miR-21 is at least partially responsible for this effect. After ingestion of melanoma-derived exosomes during incubation, mouse embryonic fibroblasts cells emerged cellular invasiveness with the presentation of a marked increase in miR-21 expression. MiR-21 promoted invasion of fibroblasts by down-regulation of tissue inhibitor of metalloproteinase 3 (TIMP3) expression and increasing of matrix metalloprotein (MMP) expression in fibroblast cells via melanoma-derived exosomes in a time-dependent manner. CONCLUSION: Our results suggest that tumor-derived exosomes may facilitate stromal fibroblasts an aggressive phenotype to equip the tumor progression.

Adenomyosis-derived extracellular vesicles endow endometrial epithelial cells with an invasive phenotype through epithelial-mesenchymal transition.

Extracellular vesicles from highly metastatic tumor cells have been shown to mediate epithelial-mesenchymal transition (EMT)-related events in recipient cells. In endometrial epithelial cells, EMT processes are known to be involved in the development of adenomyosis. We aimed to investigate whether adenomyosis-derived extracellular vesicles (AMEVs) are able to induce an EMT process in endometrial epithelial cells. In this study, AMEVs were isolated from patients with adenomyosis and characterized by transmission electron microscopy, Western blot, and nanoparticle tracking. Primary endometrial epithelial cells (EECs) were derived from normal endometrium tissues from patients with leiomyoma and co-cultured with AMEVs in vitro. AMEV uptake was examined by fluorescence confocal microscopy. The invasion of EECs was confirmed by Transwell assay. Immunohistochemistry, Western blot, and qRT-PCR were performed on EECs to illustrate the expression levels of cytokeratin 19, E-cadherin, vimentin, and zinc finger E-box-binding homeobox 1 (ZEB1). The results indicated that the cellular fluorescence intensity gradually increased after 48 h of co-culture, but decreased after 72 h. After co-culturing with AMEVs for 72 h, EECs expressed significantly lower levels of cytokeratin 19 and E-cadherin, and significantly higher levels of vimentin and ZEB1. Together these results demonstrated that AMEVs induce an EMT process and enhance the invasion of EECs. These changes may contribute to the pathogenesis and progression of adenomyosis.

Characteristics and Changes of DNA in Extracellular Vesicles.

Extracellular vesicles (EVs) have been known to carry multiple bioactive molecules, including lipids, mRNA/miRNA, and proteins. However, recent studies show that specific DNAs are also packed into EVs secreted by various cells, which are considered as powerful markers for diagnosis and prognosis of disease. DNAs in EVs are derived from parental cells, representing the mutation and even spanning of the whole genomic DNA of parental cells. Interestingly, increasing numbers of studies have found that the genetic materials in different EVs are not only universal but also random and different, which may be related to the size of EVs. In this review, we discuss the different characteristics of DNAs in EVs and the rules of their variation. We hope our review will trigger the continuing exploration of the origins, characteristics, and variations of DNAs in EVs.

Focused characteristics and effects of light reflected from spherical lipid membrane of giant unilamellar vesicles.

Lipid vesicle is spherical membranous structure with a concave surface on the inside. When a beam of light illuminates a lipid vesicle, the light reflected from the vesicular concave membrane can be focused to have higher intensity and generate enhanced effects. By observing and simulating light reflected from giant unilamellar vesicles (GUVs), the intensity distribution of the light reflected from a spherical concave lipid membrane was investigated. The reflected light had focused characteristics. Its intensity was concentrated 10,000 times and even exceeded the intensity of incident light in a confined region, creating another effective light source in the lipid vesicle. The fluorescence quenching of sulfo-Cy5 encapsulated in spherical GUVs was stronger than that of the outside solution when irradiated by a 632.8 nm laser. When irradiated with ultraviolet light C (UVC), the damage to plasmid DNA encapsulated with spherical GUVs was greater than that of pure plasmid DNA solution and plasmid DNA mixed with lipid membrane fragments. Therefore, in addition to the effects of incident light, the focused light reflected from GUVs could generate incremental effects on encapsulated photoreactive materials if the spherical structure of the lipid membrane was maintained. These results proved that concave lipid membranes of spherical vesicles can focus light and utilize it to generate enhanced effects. The capability of light focusing and its influence on DNA may provide new insights for understanding the function of lipid membranes in cellular life.

Ultrasound-enhanced delivery of doxorubicin/all-trans retinoic acid-loaded nanodiamonds into tumors.

AIM: To build up a combined therapy strategy to address limitations of the enhanced permeability and retention (EPR) effect and improve the efficiency of tumor therapy. MATERIALS & METHODS: A pH-sensitive nanocomplex for co-delivery of doxorubicin (DOX) and all-trans retinoic acid (ATRA) was developed based on nanodiamonds (DOX/ATRA-NDs) to enhance intracellular retention of drugs. Meanwhile, ultrasound was employed to enhance tumor vascular penetration of DOX-ATRA-NDs. RESULTS: The distribution of DOX/ATRA-NDs in the tumor tissues increased threefold when ultrasound was applied at 1 MHz and 0.6 W/cm2. Comparing with unmodified chemotherapeutics, the combined therapy induced more tumor cells apoptosis and greater tumor growth inhibition in both liver and breast tumor models. CONCLUSION: DOX-ATRA-NDs demonstrate great potential in clinical applications.

Encapsulation of Nucleic Acids into Giant Unilamellar Vesicles by Freeze-Thaw: a Way Protocells May Form.

Protocells are believed to consist of a lipid membrane and encapsulated nucleic acid. As the lipid membrane is impermeable to macromolecules like nucleic acids, the processes by which nucleic acids become encapsulated inside lipid membrane compartments are still unknown. In this paper, a freeze-thaw method was modified and applied to giant unilamellar vesicles (GUVs) and deoxyribonucleic acid (DNA) in mixed solution resulting in the efficient encapsulation of 6.4 kb plasmid DNA and similar length linear DNA into GUVs. The mechanism of encapsulation was followed by observing the effect of freeze-thaw temperatures on GUV morphological change, DNA encapsulation and ice crystal formation, and analyzing their correlation. Following ice crystal formation, the shape of spherical GUVs was altered and membrane integrity was damaged and this was found to be a necessary condition for encapsulation. Heating alone had no effects on DNA encapsulation, but was helpful for restoring the spherical shape and membrane integrity of GUVs damaged during freezing. These results suggested that freeze-thaw could promote the encapsulation of DNA into GUVs by a mechanism: the vesicle membrane was breached by ice crystal formation during freezing, DNA entered into damaged GUVs through these membrane gaps and was encapsulated after the membrane was resealed during the thawing process. The process described herein therefore describes a simple way for the encapsulation of nucleic acids and potentially other macromolecules into lipid vesicles, a process by which early protocells might have formed.

Lactation-Related MicroRNA Expression in Microvesicles of Human Umbilical Cord Blood.

BACKGROUND The complex process by which lactation is initiated upon neonate delivery remains incompletely understood. Microvesicles (MVs) can transmit microRNAs (miRNAs) into recipient cells to influence cell function, and recent studies have identified miRNAs essential for mammary gland development and lactation. This study aimed to investigate the expression of lactation-related miRNAs in MVs isolated from human umbilical cord blood immediately after delivery. MATERIAL AND METHODS Umbilical cord blood samples were collected from 70 healthy pregnant women, and MVs were isolated through differential centrifugation and characterized by transmission electron microscopy, Western blotting, and nanoparticle tracking analysis. Lactation-related miRNAs were screened using bioinformatics tools for miRNA target prediction, gene ontology, and signaling pathway analyses. miRNA PCR arrays were used for miRNA expression analysis, and the results were validated by real-time PCR. Upon exposure of HBL-100 human mammary epithelial cells to MVs, MV uptake was examined by fluorescence confocal microscopy and b-casein secretion was detected by ELISA. RESULTS Spherical MVs extracted from umbilical cord blood expressed CD63 and had an average diameter of 167.0±77.1 nm. We profiled 337 miRNAs in human umbilical cord blood MVs and found that 85 were related to lactation by bioinformatics analysis. The 25 most differentially expressed lactation-related miRNAs were validated by real-time PCR. MV uptake by HBL-100 cells was after 4 h in culture, and significantly increased secretion of ß-casein was observed after 96 h from cells exposed to MVs (P<0.05). CONCLUSIONS Umbilical cord blood MVs contain many lactation-related miRNAs and can induce ß-casein production by HBL-100 cells in vitro. Thus, umbilical cord blood MVs may mediate secretion of ß-casein through miRNAs, thereby playing an important role in fetal-maternal crosstalk.

Dickkopf Wnt signaling pathway inhibitor 1 regulates the differentiation of mouse embryonic stem cells in vitro and in vivo.

Embryonic stem cells (ESCs) are pluripotent stem cells derived from early stage embryos. It remains unclear whether inhibiting the Wnt/ß­catenin signaling pathway using dickkopf Wnt signaling pathway inhibitor 1 (DKK1) impacts on the differentiation potential of mouse ESCs in vitro and in vivo. In the present study, immunohistochemical staining was used to measure the expression of markers of the three germ layers in ESCs and teratomas derived from ESCs. The expression of markers for the Wnt/ß­catenin signaling pathway were detected by reverse transcription­polymerase chain reaction (RT­qPCR). Immunohistochemistry and western blotting indicated that the expression levels of octamer­binding transcription factor 4 in the DKK1­treated ESC group were significantly greater compared with the control ESCs. Reduced expression levels of NeuroD and bone morphogenetic protein 4 were observed in the DKK1­treated ESCs and teratomas derived from DKK1­treated ESCs compared with the control group. Increased expression levels of SOX17 were observed in the DKK1­treated ESCs compared with the control group. RT­qPCR indicated that ß­catenin expression was significantly reduced in DKK1­treated ESCs and teratomas derived from DKK1­treated ESCs compared with the control groups. Western blotting indicated no alterations in the expression of GSK­3ß, however, the levels of phosphorylated­GSK­3ß were significantly greater in the DKK1 treatment groups, while cyclin D1 and c­Myc expression levels were significantly reduced in the DKK1 treatment groups compared with the control groups. These results suggest that inhibiting Wnt signaling in ESCs using DKK1 may promote mouse ESCs to differentiate into endoderm in vitro and in vivo, and suppress the tumorigenicity of ESCs.

Differential expression of estrogen receptor α and ß isoforms in multiple and solitary leiomyomas.

Uterine leiomyomas are benign myometrial neoplasms that function as one of the common indications for hysterectomy. Clinical and biological evidences indicate that uterine leiomyomas are estrogen-dependent. Estrogen stimulates cell proliferation through binding to the estrogen receptor (ER), of which both subtypes α and ß are present in leiomyomas. Clinically, leiomyomas may be singular or multiple, where the first one is rarely recurring if removed and the latter associated to a relatively young age or genetic predisposition. These markedly different clinical phenotypes indicate that there may different mechanism causing a similar smooth muscle response. To investigate the relative expression of ERα and ERß in multiple and solitary uterine leiomyomas, we collected samples from 35 Chinese women (multiple leiomyomas n = 20, solitary leiomyoma n = 15) undergoing surgery to remove uterine leiomyomas. ELISA assay was performed to detect estrogen(E2) concentration. Quantitative real-time PCR analysis was performed to detect ERα and ERß mRNA expression. Western blot and immunohistochemical analysis were performed to detect ERα and ERß protein expression. We found that ERα mRNA and protein levels of in multiple leiomyomas were significantly lower than those of solitary leiomyomas, whereas ERß mRNA and protein levels in multiple leiomyomas were significantly higher than those in solitary leiomyomas, irrespectively of the menstrual cycle stage. In both multiple and solitary leiomyomas, ERα expression was higher than that of ERß. E2 concentration in multiple and solitary leiomyomas correlated with that of ERα expression. ERα was present in nuclus and cytoplasma while estrogen receptor ß localized only in nuclei in both multiple and solitary leiomyomas. Our findings suggest that the difference of ERα and ERß expression between multiple and solitary leiomyomas may be responsible for the course of the disease subtypes.

An in vivo study of the effects on serum glucose, amylase and histopathology of the feline pancreatic tissue treated by focused ultrasound.

Pancreatic cancer is one of the most malignant neoplasms originating in the digestive system. Focused ultrasound (FUS) treatment instead of the surgery operation has been used to treat Pancreatic cancer noninvasively in clinical trials. The endocrine and exocrine glands in pancreas provide the two unique functions for a person to be healthy. It is critically important to find out if the FUS treatment can still keep the normal functions of the two glands. The goal of this study is to examine and analyze changes in histopathology and serum glucose and amylase levels of the targeted in-vivo felines after the FUS treatment. Various percentage volumes of pancreas of felines were insonified. The FUS treatment (7.5 MHz of central frequency; 5 W of acoustical power; transducer f-number = 0.33; 6 s insonification time per point) effectively generated coagulative necrosis at the insonified site while leaving tissue outside the insonified site intact. It was also observed that all felines endured well with the FUS treatment; changes introduced to pancreatic tissue after up to 50% of a pancreas by volume was insonified by the FUS procedure did not affect its normal endocrine and exocrine functions.

[Effect of high-intensity focused ultrasound combined with gemcitabine on subcutaneous pancreatic cancer in nude mice].

OBJECTIVE: To investigate the effect of high-intensity focused ultrasound (HIFU) and gemcitabine on xenograft growth in nude mice bearing human pancreatic cancer. METHODS: Nude mouse models bearing subcutaneous human pancreatic cancer cell line PANC-1 xenograft were randomized into 4 groups, including a control group and 3 treatment groups subjected to treatments with HIFU, gemcitabine, or both. After the treatments, the tumor was measured on a weekly basis for 5 weeks, and the tumor growth curve was drawn. The tumor inhibition rate was calculated and the expression of vascular endothelial growth factor (VEGF) in the tumor tissue was examined by immunohistochemistry. RESULTS: The tumor volume showed significant differences between the 3 treatment groups (P<0.01), but all significantly smaller than that in the control group; HIFU combined with gemcitabine resulted in the most obvious reduction in the tumor volume. VEGF expression in the tumor tissue was the lowest in the combined treatment group and the highest in the control group. CONCLUSION: HIFU therapy produces definite therapeutic effect on human pancreatic cancer in the nude mouse model, and its combination with chemotherapy is the optimal treatment modality.

RNAi-mediated MMP-9 silencing inhibits mouse melanoma cell invasion and migration in vitro and in vivo.

MMP-9 participates in tumour growth, invasion, metastasis and vascularisation. Thus, inhibition of MMP-9 may be involved in the process of tumourigenesis. We have investigated the effect of RNAi-mediated MMP-9 silencing on inhibiting invasion and migration of mouse melanoma cell B16. A specific and optimised siRNA vector was used to target MMP-9 mRNA synthesis in B16 cells. Changes of invasion and migration capability of B16 cell were examined after transfection at different time, and a footpad tumour model was performed to measure the effect of MMP-9 siRNA on melanoma tumourigenesis in vivo. In vitro, down-regulation of MMP-9 expression significantly inhibited B16 cell invasion and migration. In vivo, intratumoural injection of plasmid DNA expressing MMP-9 siRNA every 3 days for three times remarkably inhibited melanoma growth and also suppressed tumour metastasis. The results indicate that RNA-mediated targeting of MMP-9 may have promising applications for the treatment of melanoma.