Targeted Microbubbles for Ultrasound Mediated Short Hairpin RNA Plasmid Transfection to Inhibit Survivin Gene Expression and Induce Apoptosis of Ovarian Cancer A2780/DDP Cells

Nanotherapeutic approaches for delivery of long non-coding RNAs: an updated review with emphasis on cancer

The long noncoding RNAs (lncRNAs) comprise a wide range of RNA species whose length exceeds 200 nucleotides, which regulate the expression of genes and cellular functions in a wide range of organisms. Several diseases, including malignancy, have been associated with lncRNA dysregulation. Due to their functions in cancer development and progression, lncRNAs have emerged as promising biomarkers and therapeutic targets in cancer diagnosis and treatment. Several studies have investigated the anti-cancer properties of lncRNAs; however, only a few lncRNAs have been found to exhibit tumor suppressor properties. Furthermore, their length and poor stability make them difficult to synthesize. Thus, to overcome the instability of lncRNAs, poor specificity, and their off-target effects, researchers have constructed nanocarriers that encapsulate lncRNAs. Recently, translational medicine research has focused on delivering lncRNAs into tumor cells, including cancer cells, through nano-drug delivery systems in vivo. The developed nanocarriers can protect, target, and release lncRNAs under controlled conditions without appreciable adverse effects. To deliver lncRNAs to cancer cells, various nanocarriers, such as exosomes, microbubbles, polymer nanoparticles, 1,2-dioleyl-3-trimethylammoniumpropane chloride nanocarriers, and virus-like particles, have been successfully developed. Despite this, every nanocarrier has its own advantages and disadvantages when it comes to delivering nucleic acids effectively and safely. This article examines the current status of nanocarriers for lncRNA delivery in cancer therapy, focusing on their potential to enhance cancer treatment.

Delivery of Anticancer Drugs Using Microbubble-Assisted Ultrasound in a 3D Spheroid Model

Tumor spheroids are promising three-dimensional (3D) in vitro tumor models for the evaluation of drug delivery methods. The design of noninvasive and targeted drug methods is required to improve the intratumoral bioavailability of chemotherapeutic drugs and reduce their adverse off-target effects. Among such methods, microbubble-assisted ultrasound (MB-assisted US) is an innovative modality for noninvasive targeted drug delivery. The aim of the present study is to evaluate the efficacy of this US modality for the delivery of bleomycin, doxorubicin, and irinotecan in colorectal cancer (CRC) spheroids. MB-assisted US permeabilized the CRC spheroids to propidium iodide, which was used as a drug model without affecting their growth and viability. Histological analysis and electron microscopy revealed that MB-assisted US affected only the peripheral layer of the CRC spheroids. The acoustically mediated bleomycin delivery induced a significant decrease in CRC spheroid growth in comparison to spheroids treated with bleomycin alone. However, this US modality did not improve the therapeutic efficacy of doxorubicin and irinotecan on CRC spheroids. In conclusion, this study demonstrates that tumor spheroids are a relevant approach to evaluate the efficacy of MB-assisted US for the delivery of chemotherapeutics.

Silencing TLR4 using an ultrasound-targeted microbubble destruction-based shRNA system reduces ischemia-induced seizures in hyperglycemic rats

The toll-like receptor 4 (TLR4) pathway is involved in seizures. We investigated whether ultrasound-targeted microbubble destruction (UTMD)-mediated delivery of short hairpin RNA (shRNA) targeting the TLR4 gene (shRNA-TLR4) can reduce ischemia-induced seizures in rats with hyperglycemia. A total of 100 male Wistar rats were randomly assigned to five groups: (1) Sham; (2) normal saline (NS); (3) shRNA-TLR4, where rats were injected with shRNA-TLR4; (4) shRNA-TLR4 + US, where rats were injected with shRNA-TLR4 followed by ultrasound (US) irradiation; and (5) shRNA-TLR4 + microbubbles (MBs) + US, where rats were injected with shRNA-TLR4 mixed with MBs followed by US irradiation. Western blot and immunohistochemical staining were used to measure TLR4-positive cells. Half of the rats in the NS group developed tonic-clonic seizures, and TLR4 expression in the CA3 region of the hippocampus was increased in these rats. In addition, the NS group showed an increased number of TLR4-positive cells compared with the Sham group, while there was a decreased number of TLR4-positive cells in the shRNA, shRNA + US, and shRNA + MBs + US groups. Our findings indicate that the TLR4 pathway is involved in the pathogenesis of ischemia-induced seizures in hyperglycemic rats and that UTMD technology may be a promising strategy to treat brain diseases.

Evaluation of the potential of ultrasound-mediated drug delivery for the treatment of ovarian cancer through preclinical studies

Ovarian cancer (OC) has the greatest mortality rate among gynecological cancers, with a five-year survival rate of <50%. Contemporary adjuvant chemotherapy mostly fails in the case of OCs that are refractory, metastatic, recurrent, and drug-resistant. Emerging ultrasound (US)-mediated technologies show remarkable promise in overcoming these challenges. Absorption of US waves by the tissue results in the generation of heat due to its thermal effect causing increased diffusion of drugs from the carriers and triggering sonoporation by increasing the permeability of the cancer cells. Certain frequencies of US waves could also produce a cavitation effect on drug-filled microbubbles (MBs, phospholipid bilayers) thereby generating shear force and acoustic streaming that could assist drug release from the MBs, and promote the permeability of the cell membrane. A new class of nanoparticles that carry therapeutic agents and are guided by US contrast agents for precision delivery to the site of the ovarian tumor has been developed. Phase-shifting of nanoparticles by US sonication has also been engineered to enhance the drug delivery to the ovarian tumor site. These technologies have been used for targeting the ovarian cancer stem cells and protein moieties that are particularly elevated in OCs including luteinizing hormone-releasing hormone, folic acid receptor, and vascular endothelial growth factor. When compared to healthy ovarian tissue, the homeostatic parameters at the tissue microenvironment including pH, oxygen levels, and glucose metabolism differ significantly in ovarian tumors. US-based technologies have been developed to take advantage of these tumor-specific alterations for precision drug delivery. Preclinical efficacy of US-based targeting of currently used clinical chemotherapies presented in this review has the potential for rapid human translation, especially for formulations that use all substances that are deemed to be generally safe by the U.S. Food and Drug Administration.

Ultrasound microbubble-mediated delivery of ANLN silencing-repressed EZH2 expression alleviates cervical cancer progression

Ultrasound-targeted microbubble destruction (UTMD) is a new gene therapy method that uses ultrasound and microbubbles carrying target genes to achieve gene transfection. However, whether UTMD-mediated ANLN silencing transfection helps to restrain the growth of cervical cancer (CC) is obscure. ANLN level in tumor tissues, adjacent tissues, and cells was tested using the database, qRT-PCR, and western blot. The optimal concentration of SF6 was determined by MTT assay. Mechanical index (MI) was selected by flow cytometry. After transfection with liposome or UTMD-mediated liposome, cell function experiments, qRT-PCR, and western blot were employed to assess CC cell biological behaviors and EZH2 level. Epithelial-mesenchymal transition (EMT)-related marker and apoptosis-related marker expressions were examined utilizing qRT-PCR and western blot. 10% SF6 and MI of 0.28 were selected for subsequent tests. ANLN was highly expressed in CC and cells. The transfection efficiency of the UTMD-siANLN group was higher than that of the L-siANLN group. Moreover, the repression of UTMD-siANLN on CC cell malignant phenotypes was stronger than L-siANLN. UTMD-siANLN attenuated EZH2 expression in CC cells. The modulatory role of UTMD-siANLN on EMT- and apoptosis-related markers was reversed by EZH2 overexpression. UTMD can improve the efficiency of siANLN transfection into CC cells to induce suppression of CC cell malignant phenotypes, which may become a new target of gene therapy for CC.

Highlights in ultrasound-targeted microbubble destruction-mediated gene/drug delivery strategy for treatment of malignancies

Ultrasound is one of the safest and most advanced medical imaging technologies that is widely used in clinical practice. Ultrasound microbubbles, traditionally used for contrast-enhanced imaging, are increasingly applied in Ultrasound-targeted Microbubble Destruction (UTMD) technology which enhances tissue and cell membrane permeability through cavitation and sonoporation, to result in a promising therapeutic gene/drug delivery strategy. Here, we review recent developments in the application of UTMD-mediated gene and drug delivery in the diagnosis and treatment of tumors, including the concept, mechanism of action, clinical application status, and advantages of UTMD. Furthermore, the future perspectives that should be paid more attention to in this field are prospected.

Gemcitabine-loaded microbubble system for ultrasound imaging and therapy

Ultrasound imaging presents many positive attributes, including safety, real-time imaging, universal accessibility, and cost. However, inherent difficulties in discrimination between soft tissues and tumors prompted development of stabilized microbubble contrast agents. This presents the opportunity to develop agents in which drug is entrapped in the microbubble shell. We describe preparation and characterization of theranostic poly(lactide) (PLA) and pegylated PLA (PEG-PLA) shelled microbubbles that entrap gemcitabine, a commonly used drug for pancreatic cancer (PDAC). Entrapping 6 wt% gemcitabine did not significantly affect drug activity, microbubble morphology, or ultrasound contrast activity compared with unmodified microbubbles. In vitro microbubble concentrations yielding ≥ 500nM entrapped gemcitabine were needed for complete cell death in MIA PaCa-2 PDAC drug sensitivity assays, compared with 62.5 nM free gemcitabine. In vivo administration of gemcitabine-loaded microbubbles to xenograft MIA PaCa-2 PDAC tumors in athymic mice was well tolerated and provided substantial tumoral image enhancement before and after destructive ultrasound pulses. However, no significant differences in tumor growth were observed among treatment groups, in keeping with the in vitro observation that much higher doses of gemcitabine are required to mirror free gemcitabine activity. STATEMENT OF SIGNIFICANCE: The preliminary results shown here are encouraging and support further investigation into increased gemcitabine loading. Encapsulation of gemcitabine within polylactic acid (PLA) microbubbles does not damage its activity towards pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC) cells. Excellent imaging and evidence of penetration into the highly desmoplastic PDAC tumors is demonstrated. Microbubble destruction was confirmed in vivo, showing that elevated mechanical index shatters the microbubbles for enhanced delivery. The potential to slow PDAC growth in vivo is shown, but higher gemcitabine concentrations are required. Current efforts are directed at increasing drug loading by inclusion of drug-carrying nanoparticles for effective in vivo treatment.

Microbubbles versus Extracellular Vesicles as Therapeutic Cargo for Targeting Drug Delivery

Extracellular vesicles (EVs) and microbubbles are nanoparticles in drug-delivery systems that are both considered important for clinical translation. Current research has found that both microbubbles and EVs have the potential to be utilized as drug-delivery agents for therapeutic targets in various diseases. In combination with EVs, microbubbles are capable of delivering chemotherapeutic drugs to tumor sites and neighboring sites of damaged tissues. However, there are no standards to evaluate or to compare the benefits of EVs (natural carrier) versus microbubbles (synthetic carrier) as drug carriers. Both drug carriers are being investigated for release patterns and for pharmacokinetics; however, few researchers have focused on their targeted delivery or efficacy. In this Perspective, we compare EVs and microbubbles for a better understanding of their utility in terms of delivering drugs to their site of action and future clinical translation.

Ultrasound Microbubble-Mediated VHL Regulates the Biological Behavior of Ovarian Cancer Cells

According to the literature, the von Hippel-Lindau (VHL) gene has a certain correlation with ovarian cancer. In this study, we investigated the effect and mechanism of ultrasound microbubble-mediated VHL on the biological function of ovarian cancer cells. Non-targeting lipid microbubbles and targeted lipid microbubbles were prepared. OVCAR-3 cells were treated with VHL mediated by ultrasound and microbubbles alone or together. Expressions of VHL, Akt, epithelial-mesenchymal-transition-related proteins and apoptosis-related proteins were detected by Western blot and quantitative real-time polymerase chain reaction as needed. The effect of ultrasound microbubble-mediated VHL on the proliferation, apoptosis, cell cycle, migration and invasion of OVCAR-3 cells was examined by Cell Counting Kit-8, flow cytometry, wound-healing assay and Transwell. Compared with other treatment methods, ultrasound microbubble mediation enhanced VHL expression in OVCAR-3 cells. Overexpression of liposome-mediated VHL inhibited the proliferation and migration; caused cell-cycle arrest; promoted apoptosis: downregulated the expressions of MMP2, MMP9, E-cadherin, Akt and Bcl-2; and upregulated the expressions of VHL and BCL2-associated X protein (BAX) in OVCAR-3 cells. The effect of microbubble-treated VHL was similar to liposome-mediated regulation, while ultrasound treatment enhanced the effect of VHL on OVCAR-3 cells. More interestingly, ultrasound microbubble-mediated VHL had the most obvious regulatory effect on OVCAR-3 cells. Ultrasound microbubble technology increases the transfection efficiency of VHL into OVCAR-3 cells and enhances the effect of VHL gene on the biological function of OVCAR-3 cells.

Targeted rod-shaped mesoporous silica nanoparticles for the co-delivery of camptothecin and survivin shRNA in to colon adenocarcinoma in vitro and in vivo

Simultaneous drug and gene delivery to cancer cells has been introduced to provide advantages of the synergistic effects of gene to sensitize the cancer cells to chemotherapeutic agent. In the current study, nucleolin-targeted co-delivery system, based on PEGylated rod-shaped mesoporous silica NPs was developed as a biocompatible nanocarrier for simultaneous delivery of camptothecin and survivin shRNA-expressing plasmid (iSur-DNA) to colon adenocarcinoma. The structural characterization including hydrodynamic radius and morphological characteristics of the prepared system demonstrated the mesoporous rod-shaped structure of the prepared system with 100-150 nm diameter. Camptothecin was loaded into the rod-shaped MSN NPs with encapsulation efficiency of 32%. At the next stage, the prepared camptothecin-loaded system was PEGylated and then iSur-DNA was condensed with C/P ratio of 6 to form PEG@MSNR-CPT/Sur. Then, the prepared camptothecin-iSur-DNA loaded PEGylated rod-shaped mesoporous silica NPs were tagged with AS1411 DNA aptamer (Apt-PEG@MSNR-CPT/Sur) in order to provide selective therapy against colorectal adenocarcinoma. The obtained results showed that the prepared platform controlled the release of anticancer drug, camptothecin. The experimental results indicated potent synergistic effect of iSur-pDNA and CPT in in vitro cytotoxicity, apoptosis induction and in vivo antitumor effect. In addition, tagging the system with AS1411 DNA aptamer facilitated drug uptake into nucleolin positive colorectal cancer cells leading to higher cellular toxicity and apoptosis induction in C26 cells compared to nucleolin-negative CHO cell line. Apt-PEG@MSNR-CPT/Sur system significantly supressed tumor growth rate in C26 tumor bearing mice while improving survival rate and pharmacokinetics of the platform in comparison with PEG@MSNR-CPT and PEG@MSNR-CPT/Sur. It could be concluded that the developed nucelolin targeted nanomedicine for co-delivery of camptothecin and iSur-DNA could serve as a versatile nanotherapeutic system against colorectal cancer.

New insights on the role of ROS in the mechanisms of sonoporation-mediated gene delivery

Reactive oxygen species (ROS) are hypothesized to play a role in the sonoporation mechanisms. Nevertheless, the acoustical phenomenon behind the ROS production as well as the exact mechanisms of ROS action involved in the increased cell membrane permeability are still not fully understood. Therefore, we investigated the key processes occurring at the molecular level in and around microbubbles subjected to ultrasound using computational chemistry methods. To confirm the molecular simulation predictions, we measured the ROS production by exposing SonoVue® microbubbles (MBs) to ultrasound using biological assays. To investigate the role of ROS in cell membrane permeabilization, cells were subjected to ultrasound in presence of MBs and plasmid encoding reporter gene, and the transfection level was assessed using flow cytometry. The molecular simulations showed that under sonoporation conditions, ROS can form inside the MBs. These radicals could easily diffuse through the MB shell toward the surrounding aqueous phase and participate in the permeabilization of nearby cell membranes. Experimental data confirmed that MBs favor spontaneous formation of a host of free radicals where HO was the main ROS species after US exposure. The presence of ROS scavengers/inhibitors during the sonoporation process decreased both the production of ROS and the subsequent transfection level without significant loss of cell viability. In conclusion, the exposure of MBs to ultrasound might be the origin of chemical effects, which play a role in the cell membrane permeabilization and in the in vitro gene delivery when generated in its proximity.

New Aspects of Ultrasound-Mediated Targeted Delivery and Therapy for Cancer

Ultrasound-mediated targeted delivery (UMTD), a novel delivery modality of therapeutic materials based on ultrasound, shows great potential in biomedical applications. By coupling ultrasound contrast agents with therapeutic materials, UMTD combines the advantages of ultrasound imaging and carrier, which benefit deep tissue penetration and high concentration aggregation. In this paper we introduced recent advances in ultrasound contrast agents and applications in tumor therapy. Ultrasound contrast agents were categorized by their functions, mainly including thermosensitive, pH-sensitive and photosensitive ultrasound contrast agents. The various applications of UMTD in tumor treatment were summarized as follows: drug therapy, transfection of anti-oncogene, RNA interference, vaccine immunotherapy, monoclonal antibody immunotherapy, adoptive cellular immunotherapy, cytokine immunotherapy, and so on. In the end, we elaborated on the current challenges and provided perspectives of UMTD for clinical applications.

Enhanced Amikacin Diffusion With Ultrasound and Microbubbles in a Mechanically Ventilated Condensed Lung Rabbit Model

The poor diffusion of intravenous antibiotics in lung tissue makes nosocomial pneumonia challenging to treat, notably in critical patients under mechanical ventilation. The combination of ultrasound and microbubbles (USMB) is an emerging method for non-invasive and targeted enhancement of uptake of various drugs in several organs. This study aims to evaluate if USMB may increase amikacin concentration in condensed lung tissues in a mechanically ventilated rabbit model. When applied 60 or 160 min after the beginning of an intravenous amikacin infusion, USMB increased amikacin concentration in the condensed lung tissue by 1.33 (p = 0.025) or 1.56-fold (p = 0.028) respectively. When applied 70 min after the beginning of an intravenous amikacin infusion, USMB increased amikacin concentration in the muscle tissue by 2.52 (p = 0.025). In conclusion, this study demonstrates that USMB is a promising method for the targeted delivery of amikacin in mechanically ventilated condensed lung, thus opening new therapeutic fields against lung infections.

A Macro Lens-Based Optical System Design for Phototherapeutic Instrumentation

Light emitting diode (LED) and ultrasound have been powerful treatment stimuli for tumor cell growth due to non-radiation effects. This research is the first preliminary study of tumor cell suppression using a macro-lens-supported 460-nm LED combined with high-frequency ultrasound. The cell density, when exposed to the LED combined with ultrasound, was gradually reduced after 30 min of induction for up to three consecutive days when 48-W DC, 20-cycle, and 50 V_p-p sinusoidal pulses were applied to the LEDs through a designed macro lens and to the ultrasound transducer, respectively. Using a developed macro lens, the non-directional light beam emitted from the LED could be localized to a certain spot, likewise with ultrasound, to avoid additional undesirable thermal effects on the small sized tumor cells. In the experimental results, compared to LED-only induction (14.49 ± 2.73%) and ultrasound-only induction (13.27 ± 2.33%), LED combined with ultrasound induction exhibited the lowest cell density (6.25 ± 1.25%). Therefore, our measurement data demonstrated that a macro-lens-supported 460-nm LED combined with an ultrasound transducer could possibly suppress early stage tumor cells effectively.

Microbubble Formulations: Synthesis, Stability, Modeling and Biomedical Applications

Microbubbles are increasingly being used in biomedical applications such as ultrasonic imaging and targeted drug delivery. Microbubbles typically range from 0.1 to 10 µm in size and consist of a protective shell made of lipids or proteins. The shell encapsulates a gaseous core containing gases such as oxygen, sulfur hexafluoride or perfluorocarbons. This review is a consolidated account of information available in the literature on research related to microbubbles. Efforts have been made to present an overview of microbubble synthesis techniques; microbubble stability; microbubbles as contrast agents in ultrasonic imaging and drug delivery vehicles; and side effects related to microbubble administration in humans. Developments related to the modeling of microbubble dissolution and stability are also discussed.

Ultrasound-Targeted Delivery Technology: A Novel Strategy for Tumor- Targeted Therapy

Background:

Ultrasound has been widely used in clinical diagnosis because it is noninvasive, inexpensive, simple, and reproducible. With the development of molecular imaging, material science, and ultrasound contrast agents, ultrasound-targeted delivery technology has emerged. The interaction of ultrasound and molecular probes can be exploited to change the structures of cells and tissues in order to promote the targeted release of therapeutic substances to local tumors. The targeted delivery of drugs, genes, and gases would not only improve the efficacy of tumor treatment but also avoid the systemic toxicity and side effects caused by antitumor treatments. This technology was recently applied in clinical trials and showed enormous potential for clinical application.

Objective:

This article briefly introduces the characteristics of the tumor microenvironment and the principle of ultrasound-targeted delivery technology. To present recent progress in this field, this review focuses on the application of ultrasound-targeted delivery technology in tumor-targeted therapy, including drug delivery, gene transfection, and gas treatment.

Results:

The results of this study show that ultrasound-targeted delivery technology is a promising therapeutic strategy for tumor treatment.

Conclusion:

Ultrasound-targeted delivery technology shows promise with regard to cancer treatment.

Recent Progress in Gene Therapy for Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy in developed countries. This is due to the lack of specific symptoms that hinder early diagnosis and to the high relapse rate after treatment with radical surgery and chemotherapy. Hence, novel therapeutic modalities to improve clinical outcomes in ovarian malignancy are needed. Progress in gene therapy has allowed the development of several strategies against ovarian cancer. Most are focused on the design of improved vectors to enhance gene delivery on the one hand, and, on the other hand, on the development of new therapeutic tools based on the restoration or destruction of a deregulated gene, the use of suicide genes, genetic immunopotentiation, the inhibition of tumour angiogenesis, the alteration of pharmacological resistance, and oncolytic virotherapy. In the present manuscript, we review the recent advances made in gene therapy for ovarian cancer, highlighting the latest clinical trials experience, the current challenges and future perspectives.

Clinical value of survivin and its underlying mechanism in ovarian cancer: A bioinformatics study based on GEO and TCGA data mining

OBJECTIVE

An increasing number of studies have confirmed that survivin (BIRC5) plays essential roles in ovarian cancer. Nevertheless, inconsistent or controversial results exist in some studies. In the present study, we sought to determine the clinical significance of survivin and its potential molecular pathways.

METHODS

The correlation between survivin (BIRC5) expression and diagnostic value, prognostic value and clinicopathological features was assessed by meta-analysis with more than 4000 patients from literature, GEO and TCGA. In addition, the potential molecular mechanism of survivin in ovarian cancer was also determined.

RESULTS

The pooled sensitivity and specificity were 0.71 (95%CI: 0.68-0.74) and 0.97 (95%CI: 0.94-0.98), respectively. The AUC of sROC was 0.8765. The results showed that there was also a significant relationship between survivin expression and poor overall survival (HR: 1.24, 95%CI: 1.14-1.35, p < 0.001), disease-free survival (HR: 1.53, 95%CI: 0.57-4.09, p < 0.001), as well as higher recurrence rate (HR: 1.11, 95%CI: 0.97-1.27). Moreover, survivin expression was also associated with tumor progression (cancerous vs. benign, OR: 11.29, 95%CI: 8.96-14.24, p < 0.001), TNM stage (III + IV vs. I + II, OR: 5.38, 95%CI: 4.16-6.97, p < 0.001), histological grades (G3 vs. G1 ∼ G2, OR: 4.36, 95%CI: 3.29-5.77, p < 0.001), and lymphatic metastasis (metastasis vs. non-metastasis, 3.35, 95%CI 2.36-4.75, p < 0.001). Bioinformatics analysis revealed the 50 most frequently altered neighboring genes of survivin in OC, and then Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted. GO analysis showed that these genes were related to signal conduction, cell cycle, apoptosis, and metabolism. KEGG pathways analysis indicated that these genes were primarily enriched in mitotic prometaphase, PLK1 signaling events and the regulation of glucokinase by the glucokinase regulatory protein.

CONCLUSION

Survivin (BIRC5) expression might become a specific but low-sensitivity biomarker in ovarian cancer patients, and its presence indicated poor prognosis and worse TNM stages. This protein might function as an oncoprotein by influencing specific pathways involving the 50 genes identified herein. Additional studies are needed to confirm these results.

Intron-specific shRNA-mediated downregulation of survivin and promotion of apoptosis in HeLa cells

Overexpression of the survivin gene contributes to tumorigenesis; it has been recognized as an important target for cancer therapy. In the present study, survivin expression was suppressed using recombinant plasmid mediated short hairpin RNAs (shRNAs) that were constructed to target exonic or intronic sequences of the survivin gene. In addition, a negative control shRNA was constructed. HeLa cells were transfected with specific shRNA constructs and the blocking efficiency of each shRNA was assessed at the mRNA and protein levels; and the five shRNA constructs with higher blocking efficiency were selected. Cell apoptosis was assessed by flow cytometry (FCM) following Annexin V-fluorescein isothiocyanate/propidium iodide double staining. Hoechst staining was used to detect the morphological diversity of the nuclei in apoptotic cells. The results demonstrated that survivin expression was effectively reduced by the transfection of shRNAs in HeLa cells. In addition, the apoptotic rates of the shRNA-treated groups were significantly increased compared with the negative control group according to the FCM results. The nuclei of HeLa cells exhibited apoptotic characteristics in the shRNA-treated groups as identified by Hoechst staining. Survivin-targeting shRNAs effectively downregulated the expression of the gene and markedly increased the apoptotic rate of HeLa cells. Data from the present study also indicated that the intron-specific shRNA demonstrate a high efficiency of inhibition of survivin expression and were able to induce cell apoptosis of HeLa cells through RNAi, potentially providing novel target sites for tumor therapy. In conclusion, the present study suggests that intron-specific blocking of survivin by RNAi may provide a tool for anticancer therapy.

Inhibition of prostate cancer growth using doxorubicin assisted by ultrasound-targeted nanobubble destruction

Ultrasound (US)-targeted microbubble destruction has been widely used as an effective drug-delivery system. However, nanobubbles (NBs) have better stability and stronger penetration than microbubbles, and drug delivery assisted by US-targeted NB destruction (UTND) still needs to be investigated. Our aim was to investigate the effect of doxorubicin (DOX) on the inhibition of prostate cancer growth under UTND. Contrast-enhanced US imaging of transplanted PC3 prostate cancer in mice showed that under a combination of 1 W/cm² US power and a 100 Hz intermittent pulse with a “5 seconds on, 5 seconds off” mode, NBs with an average size of (485.7±33) nm were effectively destroyed within 15 minutes in the tumor location. PC3 cells and 20 tumor-bearing mice were divided into four groups: a DOX group, a DOX + NB group, a DOX + US group, and a DOX + NB + US group. The cell growth-inhibition rate and DOX concentration of xenografts in the DOX + NB + US group were highest. Based on another control group and these four groups, another 25 tumor-bearing mice were used to observe the treatment effect of nine DOX injections under UTND. The xenografts in the DOX + NB + US group decreased more obviously and had more cellular apoptosis than other groups. Finally, electron microscopy was used to estimate the cavitation effect of NBs under US irradiation in the control group, NB group, US group, and NB + US group. The results of scanning electron microscopy showed that PC3 cells in the DOX + NB + US group had more holes and significantly increased cell-surface folds. Meanwhile, transmission electric microscopy confirmed that more lanthanum nitrate particles entered the parenchymal cells in xenografts in the NB + US group compared with the other groups. This study suggested that UTND technology could be an effective method to promote drugs to function in US-irradiated sites, and the underlying mechanism may be associated with a cavitation effect.

Immunogenicity of varicella zoster virus glycoprotein E DNA vaccine

In the present study a eukaryotic expression vector of varicella zoster virus (VZV) glycoprotein E (gE) was constructed and enabled to express in COS7 cells. Furthermore, a specific immune response against the VZV gE eukaryotic expression plasmid was induced in BALB/c mice. The VZV gE gene was amplified using polymerase chain reaction (PCR) and cloned into a eukaryotic expression vector, pcDNA3.1. The recombinant vector was subsequently transfected into COS7 cells using a liposome transfection reagent. The recombinant protein was instantaneously expressed by the transfected cells, as detected by immunohistochemistry, and the recombinant pcDNA-VZV gE plasmid was subsequently used to immunize mice. Tissue expression levels were analyzed by reverse transcription-PCR. In addition, the levels of serum antibodies and spleen lymphocyte proliferation activity were investigated. The amplified target gene included the full-length gE gene (~2.7 kb), and the recombinant expression vector induced gE expression in COS7 cells. In addition, the expression plasmid induced sustained expression in vivo following immunization of mice. Furthermore, the plasmid was capable of inducing specific antibody production and effectively stimulating T cell proliferation. Effective humoral and cellular immunity was triggered in the mice immunized with the VZV gE eukaryotic expression vector. The results of the present study laid the foundation for future research into a VZV DNA vaccine.

Evaluation of Antimetastatic Effect of lncRNA-ATB siRNA Delivered Using Ultrasound-Targeted Microbubble Destruction

Hepatocellular carcinoma (HCC) is one of the most common human malignancies around the world. The poor prognosis and high recurrence rate of HCC are largely the result of the high frequencies of intrahepatic and extrahepatic metastases. However, the treatment of metastasis is very limited. Ultrasound-targeted microbubble destruction (UTMD) technology has been recognized as a promising technology for drug and gene delivery in vivo and in vitro. Long noncoding RNA activated by transforming growth factor-β (TGF-β; lncRNA-ATB) was recently identified, which was upregulated in HCC metastases and associated with poor prognosis of HCC patients. In this study, we used microbubbles for UTMD-mediated siRNA transfection to silence lncRNA-ATB expression. We found that UTMD-mediated siRNA transfection significantly inhibited lncRNA-ATB expression and ZEB1 and ZEB2 expression and suppressed cell migration and invasion. We also demonstrated that transfecting siRNA against lncRNA-ATB by using UTMD was more efficient than that by using lipidosome. UTMD-mediated siRNA transfection against lncRNA-ATB may be a promising therapy for HCC metastasis.

Fluorescent genipin cross-linked REDV-conjugated polymeric microbubbles for human vascular endothelial cell (HVEC) targeting

Fluorescent polymeric microbubbles conjugated with REDV peptides were fabricated to achieve HVECs active targeting. The degradation, cytotoxicity and targeting features endowed them potential candidates in early molecular diagnosis for cardiovascular diseases.