Low intensity-pulsed ultrasound induced apoptosis of human hepatocellular carcinoma cells in vitro

Electromagnetic fields regulate calcium-mediated cell fate of stem cells: osteogenesis, chondrogenesis and apoptosis

Electromagnetic fields (EMF) are increasing in popularity as a safe and non-invasive therapy. On the one hand, it is widely acknowledged that EMF can regulate the proliferation and differentiation of stem cells, promoting the undifferentiated cells capable of osteogenesis, angiogenesis, and chondroblast differentiation to achieve bone repair purpose. On the other hand, EMF can inhibit tumor stem cells proliferation and promote apoptosis to suppress tumor growth. As an essential second messenger, intracellular calcium plays a role in regulating cell cycle, such as proliferation, differentiation and apoptosis. There is increasing evidence that the modulation of intracellular calcium ion by EMF leads to differential outcomes in different stem cells. This review summarizes the regulation of channels, transporters, and ion pumps by EMF-induced calcium oscillations. It furtherly discusses the role of molecules and pathways activated by EMF-dependent calcium oscillations in promoting bone and cartilage repair and inhibiting tumor stem cells growth.

Application of Ultrasound to Enhancing Stem Cells Associated Therapies

Pluripotent stem cell therapy exhibits self-renewal capacity and multi-directional differentiation potential and is considered an important regenerative approach for the treatment of several diseases. However, insufficient cell transplantation efficiency, uncontrollable differentiation, low cell viability, and difficult tracing limit its clinical applications and treatment outcome. Ultrasound (US) has mechanical, cavitation, and thermal effects that can produce different biological effects on organs, tissues, and cells. US can be combined with different US-responsive particles for enhanced physical-chemical stimulation and drug delivery. In the meantime, US also can provide a noninvasive and harmless imaging modality for deep tissue in vivo. An in-depth evaluation of the role and mechanism of action of US in stem cell therapy would enhance understanding of US and encourage research in this field. In this article, we comprehensively review progress in the application of US alone and combined with US-responsive particles for the promotion of proliferation, differentiation, migration, and in vivo detection of stem cells and the potential clinical applications.

A Tissue Engineering Acoustophoretic (TEA) Set-up for the Enhanced Osteogenic Differentiation of Murine Mesenchymal Stromal Cells (mMSCs)

Quickly developing precision medicine and patient-oriented treatment strategies urgently require novel technological solutions. The randomly cell-populated scaffolds usually used for tissue engineering often fail to mimic the highly anisotropic characteristics of native tissue. In this work, an ultrasound standing-wave-based tissue engineering acoustophoretic (TEA) set-up was developed to organize murine mesenchymal stromal cells (mMSCs) in an in situ polymerizing 3-D fibrin hydrogel. The resultant constructs, consisting of 17 cell layers spaced at 300 µm, were obtained by continuous wave ultrasound applied at a 2.5 MHz frequency. The patterned mMSCs preserved the structured behavior within 10 days of culturing in osteogenic conditions. Cell viability was moderately increased 1 day after the patterning; it subdued and evened out, with the cells randomly encapsulated in hydrogels, within 21 days of culturing. Cells in the structured hydrogels exhibited enhanced expression of certain osteogenic markers, i.e., Runt-related transcription factor 2 (RUNX2), osterix (Osx) transcription factor, collagen-1 alpha1 (COL1A1), osteopontin (OPN), osteocalcin (OCN), and osteonectin (ON), as well as of certain cell-cycle-progression-associated genes, i.e., Cyclin D1, cysteine-rich angiogenic inducer 61 (CYR61), and anillin (ANLN), when cultured with osteogenic supplements and, for ANLN, also in the expansion media. Additionally, OPN expression was also augmented on day 5 in the patterned gels cultured without the osteoinductive media, suggesting the pro-osteogenic influence of the patterned cell organization. The TEA set-up proposes a novel method for non-invasively organizing cells in a 3-D environment, potentially enhancing the regenerative properties of the designed anisotropic constructs for bone healing.

Ultrasound-Targeted Microbubble Destruction: Modulation in the Tumor Microenvironment and Application in Tumor Immunotherapy

Tumor immunotherapy has shown strong therapeutic potential for stimulating or reconstructing the immune system to control and kill tumor cells. It is a promising and effective anti-cancer treatment besides surgery, radiotherapy and chemotherapy. Presently, some immunotherapy methods have been approved for clinical application, and numerous others have demonstrated promising in vitro results and have entered clinical trial stages. Although immunotherapy has exhibited encouraging results in various cancer types, however, a large proportion of patients are limited from these benefits due to specific characteristics of the tumor microenvironment such as hypoxia, tumor vascular malformation and immune escape, and current limitations of immunotherapy such as off-target toxicity, insufficient drug penetration and accumulation and immune cell dysfunction. Ultrasound-target microbubble destruction (UTMD) treatment can help reduce immunotherapy-related adverse events. Using the ultrasonic cavitation effect of microstreaming, microjets and free radicals, UTMD can cause a series of changes in vascular endothelial cells, such as enhancing endothelial cells’ permeability, increasing intracellular calcium levels, regulating gene expression, and stimulating nitric oxide synthase activities. These effects have been shown to promote drug penetration, enhance blood perfusion, increase drug delivery and induce tumor cell death. UTMD, in combination with immunotherapy, has been used to treat melanoma, non-small cell lung cancer, bladder cancer, and ovarian cancer. In this review, we summarized the effects of UTMD on tumor angiogenesis and immune microenvironment, and discussed the application and progress of UTMD in tumor immunotherapy.

Combined Treatment with Ultrasound and Immune Checkpoint Inhibitors for Prostate Cancer

Background: Ultrasound (US) is mostly used for diagnostic purpose but could be used for cancer treatments with a US intensity or frequency fitted to such a purpose. Prostate cancer (PC) has the highest prevalence in the urological field, but indications for immune checkpoint inhibitors (ICIs) for PC are limited to very few cases. In this study, we compared the antitumor effect of US irradiation alone with the combined use of US and ICIs in vitro and in vivo. Methods: PC cell line TRAMP-C2 cells were used in our experiments. TRAMP-C2 cells were irradiated with US with pulse repeated frequencies (PRF) of 1, 10, and 100 Hz. Cell proliferation was evaluated by MTS assay and apoptotic cells were analyzed using flow cytometry. To verify the antitumor effect of US irradiation on PC in vivo, we conducted animal experiments using mice. TRAMP-C2-bearing mice were irradiated with US with PRF of 10 and 100 Hz. Three weeks after the start of US irradiation, anti-PD-1 antibody was administered to the mice. Finally, mice were sacrificed and tumors were collected. Immunohistochemical (IHC) analyses were assessed for cleaved caspase-3 and CD3 in tumor cell extracts. Results: Cell proliferation assays showed that 1 and 10 Hz US significantly inhibited cell survival (p < 0.0001). In addition, US irradiation induced apoptosis at 1, 10, and 100 Hz (p = 0.0129, p = 0.0150, and p = 0.0017, respectively). In animal experiments, a significant tumor growth inhibitory effect was observed at 10 and 100 Hz, and 100 Hz + ICIs (p < 0.05, respectively). Hematoxylin−eosin (H−E) staining showed a significant increase in the necrotic area of the tumor at 100 Hz and 100 Hz + ICIs (p < 0.05, respectively). In addition, under IHC staining the expression level of cleaved caspase-3 and the number of CD3-positive cells increased at 100 Hz (p < 0.05, respectively). Conclusion: US irradiation induced apoptosis in cells and reduced cell viability. In vivo tumor growth was suppressed by combined treatment with US irradiation and ICIs. Further research on immune system activation will lead to less invasive and more efficient treatments for PC.

Low-Intensity Pulsed Ultrasound Promotes Repair of 4-Vinylcyclohexene Diepoxide-Induced Premature Ovarian Insufficiency in SD Rats

Women with premature ovarian insufficiency (POI) may be more vulnerable to a variety of health risks. To seek a new method to treat the disease, the effects of low-intensity pulsed ultrasound (LIPUS) on promoting repair of ovarian injury in female SD rats induced by 4-vinylcyclohexene diepoxide (VCD) were explored in this research. A total of 24 female SD rats were subjected to intraperitoneal injection of VCD to induce POI. Successful modeling was achieved in 22 rats, which were then randomized into VCD + LIPUS group (n = 13) and VCD group (n = 9). The control group (n = 5) was injected with equal normal saline. Hematoxylin and eosin staining, enzyme-linked immunosorbent assay, Western blot analysis, scanning electron microscope, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated nick end labeling assay were applied to detect the results. The results indicated that rats in the VCD group showed disorder in the estrous cycle, the number of atresia follicles and apoptosis granulosa cells increased (p < .05). After the LIPUS treatment, the estrous cycle recovered, the number of follicles increased (p < .05), the level of E2 and anti-Müllerian hormone enhanced (p < .05), and the follicle-stimulating hormone decreased (p < .05). The expression of NF-κB p65, TNFα, Bax, ATF4, and caspase-3 in ovarian tissue was significantly decreased (p < .05). These findings showed that LIPUS could promote the repair of the VCD-induced ovarian damage in SD rats, which has the potential to be further applied in the clinic.

Application of low-intensity pulsed therapeutic ultrasound on mesenchymal precursors does not affect their cell properties

Ultrasound is considered a safe and non-invasive tool in regenerative medicine and has been used in the clinic for more than twenty years for applications in bone healing after the approval of the Exogen device, also known as low-intensity pulsed ultrasound (LIPUS). Beyond its effects on bone health, LIPUS has also been investigated for wound healing of soft tissues, with positive results for various cell processes including cell proliferation, migration and angiogenesis. As LIPUS has the potential to treat chronic skin wounds, we sought to evaluate the effects produced by a conventional therapeutic ultrasound device at low intensities (also considered LIPUS) on the migration capacity of mouse and human skin mesenchymal precursors (s-MPs). Cells were stimulated for 3 days (20 minutes per day) using a traditional ultrasound device with the following parameters: 100 mW/cm2 with 20% duty cycle and frequency of 3 MHz. At the parameters used, ultrasound failed to affect s-MP proliferation, with no evident changes in morphology or cell groupings, and no changes at the cytoskeletal level. Further, the migration and invasion ability of s-MPs were unaffected by the ultrasound protocol, and no major changes were detected in the gene/protein expression of ROCK1, integrin β1, laminin β1, type I collagen and transforming growth factor β1. Finally, RNA-seq analysis revealed that only 10 genes were differentially expressed after ultrasound stimulation. Among them, 5 encode for small nuclear RNAs and 2 encode for proteins belonging to the nuclear pore complex. Considering the results overall, while the viability of s-MPs was not affected by ultrasound stimulation and no changes were detected in proliferation/migration, RNA-seq analysis would suggest that s-MPs do respond to ultrasound. The use of 100 mW/cm2 intensity or conventional therapeutic ultrasound devices might not be optimal for the stimulation the properties of cell populations. Future studies should investigate the potential application of ultrasound using variations of the tested parameters.

Low-Intensity Pulsed Ultrasound Effect on MIO-M1 Cell Viability: Setup Validation and Standing Waves Analysis

Low-intensity pulsed ultrasound (LIPUS) has been proposed for novel therapies still under study, where similar parameters and protocols have been used for producing opposite effects that range from increasing cell viability to provoking cell death. Those divergent outcomes make the generalization of expected effects difficult for cell models not yet studied. This paper presents the effect of LIPUS on the viability of the MIO-M1 cell line for two well-established setups and different protocols; the acoustic intensities, duty factors, and treatment duration were varied. Measurements and models for acoustic and thermal analysis are included for proposing a solution to improve the reproducibility of this kind of experiments. Results indicate that MIO-M1 viability is less affected for the cells treated through a dish that is partially immersed in water; in these conditions, the cells neither show detrimental nor proliferative effects at intensities lower than 0.4 W/cm2 at 20% duty factor. However, cell viability was reduced when LIPUS was followed by cell subculturing. Treating the cells through a gel, with the culture dish placed on the transducer, increases cell mortality by the production of standing waves and mixed vibration-acoustical effects. Using the water-based setup with a 1° dish inclination reduces the effects of standing waves.

Ultrasound Therapy: Experiences and Perspectives for Regenerative Medicine

Ultrasound has emerged as a novel tool for clinical applications, particularly in the context of regenerative medicine. Due to its unique physico-mechanical properties, low-intensity ultrasound (LIUS) has been approved for accelerated fracture healing and for the treatment of established non-union, but its utility has extended beyond tissue engineering to other fields, including cell regeneration. Cells and tissues respond to acoustic ultrasound by switching on genetic repair circuits, triggering a cascade of molecular signals that promote cell proliferation, adhesion, migration, differentiation, and extracellular matrix production. LIUS also induces angiogenesis and tissue regeneration and has anti-inflammatory and anti-degenerative effects. Accordingly, the potential application of ultrasound for tissue repair/regeneration has been tested in several studies as a stand-alone treatment and, more recently, as an adjunct to cell-based therapies. For example, ultrasound has been proposed to improve stem cell homing to target tissues due to its ability to create a transitional and local gradient of cytokines and chemokines. In this review, we provide an overview of the many applications of ultrasound in clinical medicine, with a focus on its value as an adjunct to cell-based interventions. Finally, we discuss the various preclinical and clinical studies that have investigated the potential of ultrasound for regenerative medicine.

Can ultrasound irradiation be a therapeutic option for prostate cancer?

BACKGROUND

Focal therapies for prostate cancer (PC) can reduce adverse events and do not lead to androgen-independent progression. Ultrasound could be used for cancer treatments if the repetition frequency is fitted to the purpose. We investigated the possible therapeutic effect of ultrasound irradiation on PC cells.

MATERIALS AND METHODS

We irradiated two PC cell lines, androgen-dependent LNCaP and -independent PC-3 with ultrasound (3.0 W/cm² , 3 MHz, irradiation time rate: 20%) for 2 minutes for 1 day or 3 consecutive days at a repetition frequency of 1, 10, or 100 Hz in vitro. Cell proliferation and apoptosis were determined after irradiation.

RESULTS

Cell proliferation of PC-3 was significantly inhibited after 1 day (P < .0001) and 3 days (P < .0001) of 10 Hz ultrasound irradiation, and that of LNCaP after 1 day (P < .0001) and 3 days (P < .0001) of irradiation. LNCaP was more sensitive to ultrasound at both lower and higher cell density but PC-3 was only sensitive at a lower cell density (P < .01). Irradiation with 10 Hz ultrasound-induced significantly more PC-3 apoptotic cells than control (1 day, P = .0137; 3 days, P = .0386) rather than irradiation with 1 Hz. Apoptosis via caspase-3 was induced at 10 Hz in 1-day (P < .05) irradiation in both cell lines.

CONCLUSIONS

Ultrasound irradiation with even 1 day of 10 Hz significantly inhibited cell proliferation in both LNCaP and PC-3, especially by the remarkable induction of apoptosis in vitro. Our study indicated that ultrasound irradiation can be a therapeutic option for PC and further studies in vivo will be undertaken.

Pulsed Ultrasounds Reduce Pain and Disability, Increasing Rib Fracture Healing, in a Randomized Controlled Trial

INTRODUCTION

Rib fractures are an important health issue worldwide, with significant, pain, morbidity, and disability for which only symptomatic treatment exists.

OBJECTIVES

Based on our previous experimental model, the objective of the current study was to assess for the first time whether pulsed ultrasound (PUS) application could have beneficial effects on humans.

METHODS

Prospective, double-blinded, randomized, controlled trial of 51 patients. Four were excluded, and 47 were randomized into the control group (N = 23) or PUS group (N = 24). The control group received a PUS procedure without emission, and the PUS group received 1 Mhz, 0.5 W/cm2 for 1 min/cm2. Pain level, bone callus healing rate, physical and work activity, pain medication intake, and adverse events were blindly evaluated at baseline and one, three, and six months.

RESULTS

There were no significant differences at baseline between groups. PUS treatment significantly decreased pain by month 1 (P = 0.004), month 3 (P = 0.005), and month 6 (P = 0.025), significantly accelerated callus healing by month 1 (P = 0.013) and month 3 (P < 0.001), accelerated return to physical activity by month 3 (P = 0.036) and work activity (P = 0.001) by month 1, and considerably reduced pain medication intake by month 1 (P = 0.057) and month 3 (P = 0.017). No related adverse events were found in the PUS group.

CONCLUSIONS

This study is the first evidence that PUS treatment is capable of improving rib fracture outcome, significantly accelerating bone callus healing, and decreasing pain, time off due to both physical activity and convalescence period, and pain medication intake. It is a safe, efficient, and low-cost therapy that may become a new treatment for patients with stable rib fractures.

Ultrasound cavitation enhanced chemotherapy: In vivo research and clinical application

IMPACT STATEMENT

The novelty of this research is that we used ultrasound cavitation to enhance the effects of chemotherapy in the subcutaneous and orthotopic hepatic carcinomas in nude mice. Case reports of the effects of the targeting ultrasound cavitation and chemotherapy on malignant tumors in clinical patients were also examined. We found that low-frequency ultrasound cavitation combined with chemotherapy is effective in the inhibition of tumor growth to some extent.

Curcumin Encapsulated Lecithin Nanoemulsions: An Oral Platform for Ultrasound Mediated Spatiotemporal Delivery of Curcumin to the Tumor

Systemic toxicity caused by conventional chemotherapy is often regarded as one of the major challenges in the treatment of cancer. Over years, the trigger-based modality has gained much attention as it holds the spatiotemporal control over release and internalization of the drug. In this article, we are reporting an increase in the anti-tumor efficacy of curcumin due to ultrasound pulses. MDA MB 231 breast cancer and B16F10 melanoma cells were incubated with lecithin-based curcumin encapsulated nanoemulsions and exposed to ultrasound in the presence and absence of microbubble. Ultrasound induced sonoporation enhanced the cytotoxicity of curcumin in MDA MB 231 and B16F10 cancer cells in the presence of microbubble by 100- and 64-fold, respectively. To study the spatiotemporal delivery of curcumin, we developed B16F10 melanoma subcutaneous tumor on both the flanks of C57BL/6 mice but only the right tumor was exposed to ultrasound. Insonation of the right tumor spatially enhanced the cytotoxicity and enabled the substantial regression of the right tumor compared to the unexposed left tumor which grew continuously in size. This study showed that the ultrasound has the potential to target and increase the drug’s throughput to the tumor and enable effective treatment.

On-Chip Sonoporation-Based Flow Cytometric Magnetic Labeling

Tracing magnetically labeled cells with magnetic resonance imaging (MRI) is an emerging and promising approach to uncover in vivo behaviors of cells in cell therapy. Today, existing methods for the magnetic labeling of cells are cumbersome and time-consuming, which has greatly limited the progress of such studies on cell therapy. Thus, in this study, using the flow cytometric loading technology, we develop a sonoporation-based microfluidic chip (i.e., a microfluidic chip integrated with ultrasound; MCU), to achieve the safe, instant, convenient, and continuous magnetic labeling of cells. For the MCU we designed, a suitable group of operating conditions for safely and efficiently loading superparamagnetic iron oxide (SPIO) nanoparticles into DC2.4 cells was identified experimentally. Under the identified operating conditions, the DC2.4 cells could be labeled in approximately 2 min with high viability (94%) and a high labeling quantity of SPIO nanoparticles (19 pg of iron per cell). In addition, the proliferative functions of the cells were also well maintained after labeling. Furthermore, the in vivo imaging ability of the DC2.4 cells labeled using the MCU was verified by injecting the labeled cells into the leg muscle of the C57BL/6 mice. The results show that the excellent imaging outcome can be continuously achieved for 7 days at a density of 10⁶ cells/mL. This work can provide insight for the design of magnetic cell labeling devices and promote the MRI-based study of cell therapies.

Sonophoresis Enhanced Transdermal Delivery of Cisplatin in the Xenografted Tumor Model of Cervical Cancer

Background

Transdermal drug delivery system has been researched for a long time because of its advantage in decreasing side effects such as nausea, vomiting, and gastrointestinal disturbance. Sonophoresis has been shown to be very effective in promoting the transdermal delivery of drugs. This study is on purpose to research the feasibility of sonophoresis promoting cisplatin in the treatment of cervical cancer and the optimum drug delivery mode.

Methods

Thirty-two female nude-mice model of cervical cancer were randomly divided into 4 groups (n=8 in each group): control group without any intervention, low, medium and high concentration groups were treated with the corresponding cisplatin concentrations of 0.2mg/mL, 0.4mg/mL and 0.8mg/mL, respectively, with concurrent sonophoresis applied on the skin of local tumor, 1 mL at a time, once a day for a total of 5 days. Therapeutic pulsed ultrasound (TPU) was 1.0 MHz, 2.0 W/cm² and 60-min duration. Weight of mice and tumor diameters were measured every day during the intervention. The concentration of cisplatin in tumors was detected by HPLC. Meanwhile, tumor, skin, liver and kidney gross structures and ultrastructure were observed in order to evaluate the effectiveness and safety of experimental conditions. In addition, apoptosis and proliferation-related factors (MPO, Caspase-3, PCNA) were detected by immunohistochemistry, immunofluorescence and TUNEL assay.

Results

The weight of nude mice in each group showed an increasing trend, except for a decrease of weight in the 0.8 mg/mL group. No obvious tumor inhibition effect was observed. Cisplatin was detected in the 0.4 mg/mL group and 0.8 mg/mL group, with relative concentrations of 0.081±0.033 mg/mL and 0.111±0.021 mg/mL, respectively. Both skin and kidney inflammation were observed in the 0.8 mg/mL group. The expression of MPO, caspase-3 and TUNEL was concentration dependent, with the highest expression in the 0.8 mg/mL group, followed by the 0.4 mg/mL group, with no significant differences between the control and the 0.2 mg/mL group. PCNA was highly expressed in both the control and 0.2 mg/mL groups but decreased in the 0.4 mg/mL and 0.8 mg/mL groups.

Conclusion

Sonophoresis enhanced transdermal delivery of cisplatin in a xenograft tumor model of cervical cancer. Considering the occurrence of skin inflammation and renal injury caused by cisplatin, the recommended concentration to be administered is 0.4mg/mL.

Regulation of exosomes secretion by low-intensity pulsed ultrasound in lung cancer cells

Low-intensity pulsed ultrasound (LIPUS) is a noninvasive therapeutic method which gradually being used in clinic including cancers. Exosomes mediate intercellular communication functions in disease development and the potential clinical applications in diagnosis and therapy. However, few studies have discussed the relationship between LIPUS and exosomes. Herein, we show that low intensity (0.6-2.1 W/cm² or 0.6-3.4 W/cm²) LIPUS promoted exosomes secretion whereas higher intensity (3.4-5.0 W/cm² or 5.0 W/cm²) LIPUS inhibited exosomes secretion, and this phenomenon is associated with autophagy. Pretreatment with 3-MA or down-regulation of LC3 potentiated low intensity LIPUS's promotion of exosomes secretion and conferred resistance to higher intensity LIPUS's effects on exosomes secretion. Furthermore, pretreatment with PP242 attenuated LIPUS-influenced exosomes secretion while expression of constitutively active Akt (Ad-myr-Akt) elevated LIPUS-influenced exosomes secretion, implying mTOR-dependent mechanism involved. The findings indicate that LIPUS influences exosomes secretion by targeting mTOR-mediated LC3 signaling in SPC-A1 and SPC-A1-BM cells. Our data provided initial evidence to connect LIPUS and secretion of exosomes, and highlight that LIPUS may be exploited in exosome-related diseases.

Low-intensity pulsed ultrasound promotes the proliferation of human bone mesenchymal stem cells by activating PI3K/AKt signaling pathways

Low-intensity pulsed ultrasound (LIPUS) is a promising therapy that is widely used in clinical applications and fundamental research. Previous research has shown that LIPUS exposure has a positive effect on stem cell proliferation. However, the impact of LIPUS exposure on human bone marrow mesenchymal stem cells (hBMSCs) remains unknown. In our study, the effect and mechanism of LIPUS exposure on the proliferation of hBMSCs were investigated, and the optimal parameters of LIPUS were determined. hBMSCs were obtained and identified by flow cytometry, and the proliferation of hBMSCs was measured using the Cell Counting Kit-8 assay to determine cell cycle and cell count. Expression levels of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKt) pathway proteins and cyclin D1 were determined by western blot analysis. Next, hBMSCs were successfully cultured and identified as multipotent mesenchymal stem cells. We found that LIPUS could promote the proliferation of hBMSCs when the exposure time was 5 or 10 minutes per day. Furthermore, 50 or 60 mW/cm² LIPUS had a more significant effect on cell proliferation, but if cells were irradiated by LIPUS for 20 minutes once a day, an intensity of at least 50 mW/cm² could markedly inhibit cell growth. Cell cycle analysis demonstrated that LIPUS treatment drives cells to enter S and G2/M phases from the G0/G1 phase. LIPUS exposure increased phosphorylation of PI3K/AKt and significantly upregulated expression of cyclin D1. However, these effects were inhibited when cells were treated with PI3K inhibitor (LY294002), which in turn reduced LIPUS-mediated proliferation of hBMSCs. These results suggest that LIPUS exposure may be involved in the proliferation of hBMSCs via activation of the PI3K/AKt signaling pathway and high expression of cyclin D1, and the intensity of 50 or 60 mW/cm² and exposure time of 5 minutes were determined to be the optimal parameters for LIPUS exposure.

Low-intensity pulsed ultrasound in combination with SonoVue induces cytotoxicity of human renal glomerular endothelial cells via repression of the ERK1/2 signaling pathway

OBJECTIVES

Low-intensity pulsed ultrasound (LIPUS) and SonoVue have been used widely for diagnosis and therapeutic treatment. The effects of LIPUS and SonoVue on the microvascular system and underlying molecular mechanisms have not been established.

METHODS

Cultured human renal glomerular endothelial cells (HRGECs) were treated with 5-min ultrasonic irradiation, 20% SonoVue or the combination of both treatments. Cell proliferation, viablity, and apoptosis were measured by MTT assay, Trypan blue exclusion assay and flow cytometry, respectively. Activation of extracellular regulated protein kinases (ERK) were examined by Western blot.

RESULTS

We found that LIPUS and SonoVue alone do not induce cytotoxicity of HRGECs; however, the combination of the two treatments reduces cell proliferation and increases cell death. In addition, the combination of LIPUS and SonoVue suppressed the activation of ERK 1/2 in HRGRCs. With pretreatment of the inhibitor of ERK1/2 signaling, PD98059, LIPUS, and SonoVue does not induce additional cell death and inhibition of proliferation.

CONCLUSIONS

LIPUS combined with SonoVue induces cytotoxicity of HRGECs via repression of the ERK1/2 signaling pathway.

Honeysuckle flowers extract loaded Bombyx mori silk fibroin films for inducing apoptosis of HeLa cells

This study aimed to prepare silk fibroin (SF) films loaded with honeysuckle flowers extract (HFE) for inducing apoptosis of HeLa cells. We mixed solution of SF and HFE by air-drying for preparing the honeysuckle flowers extract loaded silk fibroin (SFH) films. The physical properties including morphologies, contact angle, roughness, and Z range were characterized. MTS assay and fluorescence micrographs proved that SFH films inhibited the proliferation rate of HeLa cells due to induction of HFE into SF films. Furthermore, cell apoptosis assay and cell cycle analysis confirmed that the apoptosis of HeLa cells resulted from SFH films. Therefore, SFH films designed in our study might be a promising candidate material for cancer therapy.

Inhibitory effects of low-intensity pulsed ultrasound sonication on the proliferation of osteosarcoma cells

To date, there is limited data on the biological effects of low-intensity pulsed ultrasound (LIPUS) on primary malignant bone tumors. The purpose of the present study was to investigate the antitumor effects of LIPUS on osteosarcoma cells. The effects of LIPUS on cell viability, induction of apoptosis, mitochondrial membrane potential and intracellular signaling molecules in the LM8 osteosarcoma cell line were investigated. LIPUS inhibited cell viability (P=0.0022) and mitochondrial membrane potential (P=0.0019) in LM8 cells. Flow cytometry analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling staining revealed significantly higher numbers of apoptotic (P<0.0001) and necrotic cells (P=0.0091) compared with cells without treatment. LIPUS treatment significantly increased phosphorylated Akt (P<0.0001) and IκBα (P=0.0001) levels, and reduced phosphorylated mitogen-activated protein kinase 7 (P<0.0001) and phosphorylated checkpoint kinase 1 (P=0.0008) levels. These results suggest that LIPUS is a non-invasive adjuvant therapy that is able to inhibit cellular proliferation in osteosarcoma cells.