Hematoporphyrin monomethyl ether enhances the killing action of ultrasound on osteosarcoma in vivo

Functional anti-bone tumor biomaterial scaffold: construction and application

Bone tumors, including primary bone tumors and bone metastases, have been plagued by poor prognosis for decades. Although most tumor tissue is removed, clinicians are still confronted with the dilemma of eliminating residual cancer cells and regenerating defective bone tissue after surgery. Therefore, functional biomaterial scaffolds are considered to be the ideal candidates to bridge defective tissues and restrain cancer recurrence. Through functionalized structural modifications or coupled therapeutic agents, they provide sufficient mechanical strength and osteoinductive effects while eliminating cancer cells. Numerous novel approaches such as photodynamic, photothermal, drug-conjugated, and immune adjuvant-assisted therapies have exhibited remarkable efficacy against tumors while exhibiting low immunogenicity. This review summarizes the progress of research on biomaterial scaffolds based on different functionalization strategies in bone tumors. We also discuss the feasibility and advantages of the combined application of multiple functionalization strategies. Finally, potential obstacles to the clinical translation of anti-tumor bone bioscaffolds are highlighted. This review will provide valuable references for future advanced biomaterial scaffold design and clinical bone tumor therapy.

Mitochondria-targeted organic sonodynamic therapy agents: concept, benefits, and future directions

Sonodynamic therapy (SDT) is an emerging and potentially less invasive therapeutic approach for cancer that employs ultrasound (US)-sensitive agents combined with US irradiation to generate cytotoxic reactive oxygen species (ROS) in deep tumor regions. Among various cellular organelles, the mitochondria are particularly susceptible to ROS, making them an attractive target for SDT. Organic-based SDT agents with mitochondria-targeting affinity have gained considerable interest as potential alternatives to conventional SDT agents, offering significant advantages in the field of SDT. However, to date, a comprehensive review focusing on mitochondria-targeted SDT agents has not yet been published. In this review, we provide an overview of the general concept, importance, benefits, and limitations of mitochondria-targeted organic SDT agents in comparison to conventional SDT methods. Finally, we discuss the current challenges and future directions for the design and development of efficient SDT agents. By addressing these issues, we aim to stimulate further research and advancements in the field of mitochondria-targeted SDT, ultimately facilitating the translation of these agents into clinical applications.

Spotlight on porphyrins: Classifications, mechanisms and medical applications

Photodynamic therapy (PDT) and sonodynamic therapy (SDT) are non-invasive treatment methods with obvious inhibitory effect on tumors and have few side effects, which have been widely concerned and explored by researchers. Sensitizer is the main factor in determining the therapeutic effect of PDT and SDT. Porphyrins, a group of organic compounds widespread in nature, can be activated by light or ultrasound and produce reactive oxygen species. Therefore, porphyrins as sensitizers in PDT have been widely explored and investigated for many years. Herein, we summarize the classical porphyrin compounds and their applications and mechanisms in PDT and SDT. The application of porphyrin in clinical diagnosis and imaging is also discussed. In conclusion, porphyrins have good application prospects in disease treatment as an important part of PDT or SDT, and in clinical diagnosis and imaging.

Development and characteristics of novel sonosensitive liposomes for vincristine bitartrate

The aim of drug delivery is to increase therapeutic efficacy. Externally triggered drug delivery systems enable site-specific and time-controlled drug release. To achieve this goal, our strategy was based on ultrasound-triggered release of an anticancer agent from sonosensitive liposomes (SL). To realize the ultrasound-triggered drug release, a lipophilic sonosensitizer, hematoporphyrin monomethyl ether (HMME) was incorporated into the lipid bilayer of liposomes. Once irradiated by the ultrasound in tumor tissues, the sonodynamic effect generated by HMME could lead to an efficient disruption of the lipid bilayer in the SL. After encapsulating vincristine bitartrate (VIN) as the model drug, the ultrasound-triggered lipid bilayer breakdown can trigger the instant release of VIN, enabling ultrasound-controlled chemotherapy with great specificity. In the in vitro and in vivo studies, by integrating tumor-specific targeting and stimuli-responsive controlled release into one system, VIN-loaded SL showed excellent antitumor efficacy. The SL could potentially produce viable clinical strategies for improved targeting efficiency of VIN for the treatment of related cancer. More importantly, this report provides an example of controlled release by means of a novel class of ultrasound triggering system.

Ultrasound-triggered breast tumor sonodynamic therapy through hematoporphyrin monomethyl ether-loaded liposome

Sonodynamic therapy (SDT) which employs ultrasound-triggered sonosensitizers to generate reactive oxygen species (ROS) has been proved to be effective for treatment of cancers. However, it is still desirable for sonosensitizers to be delivered to tumors as effectively as possible. In this study, we prepared the hematoporphyrin monomethyl ether (HMME)-loaded liposome as the sonosensitizers for SDT and evaluated their effects on human MCF-7 breast cancer cells in vitro and in vivo. Liposomes prepared by thin film hydration technique were about 100 nm in size with positive zeta potential and exhibited spherical in shape. Following irradiation of ultrasound which generates intracellular ROS, the liposome facilitated the delivery of HMME to tumor cells. HMME-loaded liposomes showed low cytotoxicity under basal condition but significant sonodynamic effects under ultrasonic irradiation. Notably, HMME-loaded liposomes exhibited spatial distribution of HMME in tumor tissues of mice. The promoted delivery of HMME into the tumors by liposomes was shown by the greater tumor growth inhibition than free HMME after 20-day treatment. Taken together, these results show that HMME-loaded liposome functions as a promising sonosensitizer for SDT, implying the efficient antitumor effects of HMME-based SDT on breast tumor.

Adjuvant Biophysical Therapies in Osteosarcoma

Osteosarcoma (OS) is a primary bone sarcoma, manifesting as osteogenesis by malignant cells. Nowadays, patients’ quality of life has been improved, however continuing high rates of limb amputation, pulmonary metastasis and drug toxicity, remain unresolved issues. Thus, effective osteosarcoma therapies are still required. Recently, the potentialities of biophysical treatments in osteosarcoma have been evaluated and seem to offer a promising future, thanks in this field as they are less invasive. Several approaches have been investigated such as hyperthermia (HT), high intensity focused ultrasound (HIFU), low intensity pulsed ultrasound (LIPUS) and sono- and photodynamic therapies (SDT, PDT). This review aims to summarize in vitro and in vivo studies and clinical trials employing biophysical stimuli in osteosarcoma treatment. The findings underscore how the technological development of biophysical therapies might represent an adjuvant role and, in some cases, alternative role to the surgery, radio and chemotherapy treatment of OS. Among them, the most promising are HIFU and HT, which are already employed in OS patient treatment, while LIPUS/SDT and PDT seem to be particularly interesting for their low toxicity.

A review on the use of magnetic fields and ultrasound for non-invasive cancer treatment

Current popular cancer treatment options, include tumor surgery, chemotherapy, and hormonal treatment. These treatments are often associated with some inherent limitations. For instances, tumor surgery is not effective in mitigating metastases; the anticancer drugs used for chemotherapy can quickly spread throughout the body and is ineffective in killing metastatic cancer cells. Therefore, several drug delivery systems (DDS) have been developed to target tumor cells, and release active biomolecule at specific site to eliminate the side effects of anticancer drugs. However, common challenges of DDS used for cancer treatment, include poor site-specific accumulation, difficulties in entering the tumor microenvironment, poor metastases and treatment efficiency. In this context, non-invasive cancer treatment approaches, with or without DDS, involving the use of light, heat, magnetic field, electrical field and ultrasound appears to be very attractive. These approaches can potentially improve treatment efficiency, reduce recovery time, eliminate infections and scar formation. In this review we focus on the effects of magnetic fields and ultrasound on cancer cells and their application for cancer treatment in the presence of drugs or DDS.

High-affinity graphene oxide-encapsulated magnetic Zr-MOF for pretreatment and rapid determination of the photosensitizers hematoporphyrin and hematoporphyrin monomethyl ether in human urine prior to UPLC-HRMS

In this paper, a high-affinity graphene oxide-encapsulated magnetic Zr-MOF (GO-Mag@Zr-MOF) was synthesized and characterized by SEM, TEM, and XPS for its morphology, structure, and components. Subsequently, the as-prepared GO-Mag@Zr-MOF was, for the first time, employed as magnetic solid-phase extraction (MSPE) adsorbent for pretreatment and determination of photodynamic therapy (PDT) with the photosensitizers hematoporphyrin (Hp) and hematoporphyrin monomethyl ether (HMME) in human urine samples coupled with ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). The synthesized GO-Mag@Zr-MOF revealed excellent adsorption efficiency for Hp and HMME in urine samples. Under optimal conditions, the spiked recoveries of the developed method were in the range of 89.5-105.6% with RSDs less than 10%. The limits of detection (LODs) were found to be 0.036 and 0.042 μg/L for Hp and HMME, respectively, while limits of quantitation (LOQs) were 0.12 and 0.14 μg/L. The proposed method was found to be rapid, effective, sensitive, and accurate for clinical analysis. Moreover, this paper, for the first time, carefully expounded the mass spectrum cracking mechanisms of Hp and HMME. Graphical abstract ᅟ.

How the Future of Sonography May Change the Outlook for Patients With Osteosarcoma

Sonography currently provides a variety of tools to support the diagnosis and treatment of osteosarcoma and, with the development of therapeutic ultrasound practices, could play an increasingly important role in the treatment of future patients with osteosarcoma. Currently, computed tomography, magnetic resonance imaging, and radiography are the preferred imaging modalities for bone lesions; treatment options for osteosarcoma primarily include highly toxic chemotherapies and surgeries that often result in limb loss. Unfortunately, osteosarcoma is rarely eliminated, and despite this, patients lose their lives after having a significant reduction in quality of life. Evolving therapies such as high-frequency focused ultrasound, ultrasound-enhanced delivery of photodynamic therapy, and low-intensity pulsed ultrasound may offer these patients an improved quality of life while also increasing efficacy of treatment. This canine case study illustrates the various ways in which sonography might contribute to the treatment plan for patients with osteosarcoma. It may provide a comparable model for the reimagining of treatment for future patients with osteosarcoma using a suite of therapeutic ultrasound applications.

5-Aminolevulinic Acid-Based Sonodynamic Therapy Induces the Apoptosis of Osteosarcoma in Mice

Objective

Sonodynamic therapy (SDT) is promising for treatment of cancer, but its effect on osteosarcoma is unclear. This study examined the effect of 5-Aminolevulinic Acid (5-ALA)-based SDT on the growth of implanted osteosarcoma and their potential mechanisms in vivo and in vitro.

Methods

The dose and metabolism of 5-ALA and ultrasound periods were optimized in a mouse model of induced osteosarcoma and in UMR-106 cells. The effects of ALA-SDT on the proliferation and apoptosis of UMR-106 cells and the growth of implanted osteosarcoma were examined. The levels of mitochondrial membrane potential (ΔψM), ROS production, BcL-2, Bax, p53 and caspase 3 expression in UMR-106 cells were determined.

Results

Treatment with 5-ALA for eight hours was optimal for ALA-SDT in the mouse tumor model and treatment with 2 mM 5-ALA for 6 hours and ultrasound (1.0 MHz 2.0 W/cm²) for 7 min were optimal for UMR-106 cells. SDT, but not 5-ALA, alone inhibited the growth of implanted osteosarcoma in mice (P<0.01) and reduced the viability of UMR-106 cells (p<0.05). ALA-SDT further reduced the tumor volumes and viability of UMR-106 cells (p<0.01 for both). Pre-treatment with 5-ALA significantly enhanced the SDT-mediated apoptosis (p<0.01) and morphological changes. Furthermore, ALA-SDT significantly reduced the levels of ΔψM, but increased levels of ROS in UMR-106 cells (p<0.05 or p<0.01 vs. the Control or the Ultrasound). Moreover, ALA-SDT inhibited the proliferation of osteosarcoma cells and BcL-2 expression, but increased levels of Bax, p53 and caspase 3 expression in the implanted osteosarcoma tissues (p<0.05 or p<0.01 vs. the Control or the Ultrasound).

Conclusions

The ALA-SDT significantly inhibited osteosarcoma growth in vivo and reduced UMR-106 cell survival by inducing osteosarcoma cell apoptosis through the ROS-related mitochondrial pathway.

A review of low-intensity ultrasound for cancer therapy

The literature describing the use of low-intensity ultrasound in four major areas of cancer therapy-sonodynamic therapy, ultrasound-mediated chemotherapy, ultrasound-mediated gene delivery and anti-vascular ultrasound therapy-was reviewed. Each technique consistently resulted in the death of cancer cells, and the bio-effects of ultrasound were attributed primarily to thermal actions and inertial cavitation. In each therapeutic modality, theranostic contrast agents composed of microbubbles played a role in both therapy and vascular imaging. The development of these agents is important as it establishes a therapeutic-diagnostic platform that can monitor the success of anti-cancer therapy. Little attention, however, has been given either to the direct assessment of the mechanisms underlying the observed bio-effects or to the viability of these therapies in naturally occurring cancers in larger mammals; if such investigations provided encouraging data, there could be prompt application of a therapy technique in the treatment of cancer patients.

Effect of ultrasound sonication on clonogenic survival and mitochondria of ovarian cancer cells in the presence of methylene blue

OBJECTIVES

This study aimed to investigate the effect of ultrasound sonication in the presence of methylene blue on clonogenic survival and mitochondria of ovarian cancer cells.

METHODS

Human ovarian cancer HO-8910 cells, which were incubated with different concentrations of methylene blue for 1 hour, were exposed to an ultrasonic wave for 5 seconds with intensity of 0.46 W/cm(2). Clonogenic survival of HO-8910 cells after ultrasound sonication was measured by a colony-forming unit assay. Mitochondrial structural changes were observed on transmission electron microscopy, and the mitochondrial membrane potential was evaluated by confocal laser-scanning microscopy with rhodamine 123 staining.

RESULTS

The colony-forming units of HO-8910 cells decreased considerably after ultrasound sonication in the presence of methylene blue. Transmission electron microscopy showed slightly enlarged mitochondria in the ultrasound-treated cells in the absence of methylene blue; however, seriously damaged mitochondria, even with almost complete disappearance of cristae, were found in the cells treated by ultrasound sonication in the presence of methylene blue. The mitochondrial membrane potential collapsed significantly when HO-8910 cells were treated by ultrasound sonication in the presence of methylene blue (P < .05).

CONCLUSIONS

Ultrasound sonication in the presence of methylene blue markedly damaged mitochondrial structure and function and decreased clonogenic survival of HO-8910 cells.

Progress of photodynamic therapy applications in the treatment of musculoskeletal sarcoma (Review)

Photodynamic therapy (PDT) has clinical approval for use as a minimally invasive therapeutic procedure that is able to exert selective cytotoxic activity toward pathological cells, particularly malignant cells. Following a number of recent technological improvements, PDT has been widely applied to the diagnosis and treatment of malignancies, including lung, esophageal, gastrointestinal, bladder, prostate, head and neck, oral and skin cancer. Studies have shown that osteosarcoma is a malignant tumor afflicting young adults worldwide, and recently, the incidence of bone and soft-tissue malignant tumors has been shown to be increasing, so the use of PDT has become an area of focus for the diagnosis and treatment of musculoskeletal sarcoma.

The induction of the apoptosis of cancer cell by sonodynamic therapy: a review

Ultrasound can be used not only in the examination, but also in the therapy, especially in the therapy of cancer, which has got effect in the treatment. Sonodynamic therapy is an experimental cancer therapy which uses ultrasound to enhance the cytotoxic effects of drugs known as sonosensitizers. It has been tested in vitro and in vivo. The ultrasound could penetrate the tissue and cell under some of conditions which directly changes the cell membranes permeability, thereby allowing the delivery of exogenous molecules into the cells in some degree. Ultrasound could inhibit the proliferation or induce the apoptosis of the cancer cell in vitro or in vivo. Recent research indicated low frequency and low intensity ultrasound could induce cells apoptosis, and which could be strengthened by sonodynamic sensitivities, microbubbles, chemotherapeutic drugs and so on. Most kinds of ultrasound suppressed the proliferation of cancer cell through inducing the apoptosis of cancer cell. The mechanism of apoptosis is not clear. In this review, we will focus on and discuss the mechanisms of the induction of the apoptosis of cancer cell by ultrasound.

The ABCG2 transporter is a key molecular determinant of the efficacy of sonodynamic therapy with Photofrin in glioma stem-like cells

We aimed to investigate the role of the ABCG2 transporter in the efficacy of sonodynamic therapy (SDT) with Photofrin in the glioma stem-like cells (GSCs) isolated and cultured from U251 glioma cells. Immunocytochemistry and flow cytometry analyses showed that ABCG2 was overexpressed in GSCs, and the percentage of ABCG2-positive GSCs was approximately 100%. The effect of ABCG2 on Photofrin extrusion in the absence or presence of a specific inhibitor of ABCG2 (fumitremorgin C; FTC) was investigated by determining the intracellular concentration of Photofrin in GSCs incubated with 20μg/ml Photofrin. Extrusion of Photofrin by ABCG2 was inhibited by 10μM FTC, which significantly increased the intracellular Photofrin concentration (p<0.05) from 0.32±0.11μg/10(6) cells to 0.89±0.13μg/10(6) cells. MTT and TUNEL assays showed that the antitumor effect of SDT (incubation of GSCs with 20μg/ml Photofrin for 6h in the dark and ultrasonic activation at 1.0MHz and 0.5W/cm(2) for 2min) was significantly improved by FTC pretreatment (p<0.05). Moreover, incubation of GSCs with FTC significantly increased the relative production of ROS in response to SDT. The overexpression of ABCG2 in GSCs results in efflux of Photofrin, indicating that the antitumor effect of SDT with Photofrin may be reduced in GSCs overexpressing ABCG2. However, since FTC improves the efficacy of SDT in GSCs by inhibiting ABCG2-mediated efflux of Photofrin, FTC may be useful in SDT treatment of ABCG2-expressing cancer cells.

Expression and significance of Kruppel-like factor 6 gene in osteosarcoma

PURPOSE

Osteosarcoma is primary malignant tumour of bone. Kruppel-like factor 6 (KLF6) is a tumor suppressor gene frequently inactivated in a number of human cancers and a ubiquitously expressed zinc-finger transcription factor. The present study aimed to first explore the relationship between the expression level of the KLF6 gene in osteosarcoma and the occurrence of bone tumours.

METHODS

KLF6 mRNA and protein expression levels in osteosarcoma and normal bone tissue were assayed by real-time quantitative PCR and immunohistochemistry. KLF6 mRNA and protein expression levels in osteosarcoma cells and normal osteoblasts were detected by semi-quantitative reverse transcription PCR and Western blotting, respectively.

RESULTS

Both the expression of KLF6 mRNA and protein in osteosarcoma cells and tissues were significantly lower than that in normal cells and tumour-adjacent tissues.

CONCLUSIONS

KLF6 is a putative tumor suppressor gene involved in osteosarcoma which can be used as a new therapeutic target and an important marker for early diagnosis and postoperative monitoring.

Glioma stem-like cells are less susceptible than glioma cells to sonodynamic therapy with photofrin

Despite remarkable progress in diagnosis and treatment, malignant glioma, a highly lethal cancer of the central nervous system, remains incurable. Although glioma stem-like cells (GSCs) represent a relatively small fraction of the cells in malignant glioma, they can proliferate and self renew extensively, being crucial for tumor recurrence. Cancer treatment by sonodynamic therapy (SDT) chiefly depends on antitumor effects of reactive oxygen species (ROS) generated from a sonosensitizer activated by ultrasound. Although SDT effectively kills glioma cells, its efficiency against GSCs is not established. We attempted to compare the susceptibility of GSCs to SDT, using Photofrin, a porphyrin-derivative photosensitizer, with that of glioma cells. Cell viability and apoptosis assays showed that SDT damaged both GSCs and U251 glioma cells, but GSCs were significantly less susceptible to SDT (p < 0.01). To elucidate the mechanism of the antitumor effects of SDT, we evaluated intracellular ROS production and Photofrin uptake: ROS production and Photofrin content were significantly lower (p < 0.01) in GSCs than in U251 glioma cells. Thus, cellular differences in sonosensitizer uptake and ROS production influence the antitumor effects of SDT. Furthermore, the resistance of GSCs may be caused by decreased sonosensitizer uptake due to ABCG2 overexpression.

Hypocrellin B-mediated sonodynamic action induces apoptosis of hepatocellular carcinoma cells

OBJECTIVE

The present study aims to investigate apoptosis of hepatocellular carcinoma cells induced by hypocrellin B-mediated sonodynamic action.

METHODS

The hypocrellin B concentration was kept constant at 2.5 μM and cells from the hepatocellular carcinoma HepG2 cell line were exposed to ultrasound with an intensity of 0.46 W/cm(2) for 8s. Cell cytotoxicity was quantified using an MTT assay 24 h after sonodynamic therapy (SDT) of hypocrellin B. Apoptosis was investigated using a flow cytometry with Annexin V-FITC and propidium iodine staining. Intracellular reactive oxygen species (ROS) levels were detected using a flow cytometry with 2,7-dichlorodihydrofluorecein diacetate (DCFH-DA) staining.

RESULTS

The cytotoxicity of hypocrellin B-mediated sonodynamic action on HepG2 cells was significantly higher than those of other treatments including ultrasound alone, hypocrellin B alone and sham treatment. Flow cytometry showed that hypocrellin B-induced sonodynamic action markedly enhanced the apoptotic rate of HepG2 cells. Increased ROS was observed in HepG2 cells after being treated with hypocrellin B-mediated sonodynamic action.

CONCLUSIONS

Our data demonstrated that hypocrellin B-mediated sonodynamic action remarkably induced apoptosis of HepG2 cells, suggesting that apoptosis is an important mechanism of cell death induced by hypocrellin B-mediated SDT.

TEM observation of ultrasound-induced mitophagy in nasopharyngeal carcinoma cells in the presence of curcumin

The present study was designed to observe the initiation of mitophagy in tumor cells after ultrasound treatment in the presence of curcumin under transmission electron microscopy. Nasopharyngeal carcinoma CNE2 cells were incubated with 10 μM curcumin and then exposed to ultrasound for 8 sec at an intensity of 0.46 W/cm(2). Severely swollen mitochondria, disrupted mitochondria and mitophagy were noted in the CNE2 cells after ultrasound treatment in the presence of curcumin. Our findings demonstrated that ultrasound treatment in the presence of curcumin significantly initiated mitophagy in CNE2 cells, which suggests that mitophagy serves as an important event in the process of cell death of nasopharyngeal carcinoma cells.

Low-intensity ultrasound-induced cellular destruction and autophagy of nasopharyngeal carcinoma cells

Ultrasound therapy, as a non-invasive modality, has been attracting extensive attention in the management of malignant tumors. The present study aimed to investigate low-intensity ultrasound-induced cellular destruction and autophagy in nasopharyngeal carcinoma cells in vitro. Nasopharyngeal carcinoma CNE2 cells were subjected to ultrasound exposure, as tumor model cells, at an intensity of 1.35 W/cm(2). Cytotoxicity was investigated 24 h after ultrasound treatment. Nuclear damage was observed using nuclear staining with Hoechst 33258. Mitochondrial dysfunction was measured using confocal laser scanning microscopy with rhodamine123 staining. Mitochondrial morphology and autophagy were observed using transmission electron microscopy (TEM). Low-intensity ultrasound significantly killed CNE2 cells proportional to the ultrasonic treatment time. Upon nuclear staining, nuclear condensation and typical apoptotic bodies were noted in the CNE2 cells exposed to ultrasound wave for 12 sec. A collapse in mitochondrial membrane potential was noted in the treated cells. Upon TEM, swollen mitochondria, more vacuoles and autophagy were noted after ultrasound treatment. Our findings demonstrate that low-intensity ultrasound significantly damages CNE2 cells and emphasize that autophagy may be an important event in ultrasound-induced cell death.

Apoptosis of ovarian cancer cells induced by methylene blue-mediated sonodynamic action

OBJECTIVE

The present study aims to investigate apoptosis of ovarian cancer cells induced by methylene blue (MB)-mediated sonodynamic therapy (SDT).

METHODS

The MB concentration was kept constant at 100μM and ovarian cancer HO-8910 cells were exposed to ultrasound therapy for 5s with an intensity of 0.46W/cm(2). The cytotoxicity was investigated 24h after MB-mediated sonodynamic action. Apoptosis was analyzed using a flow cytometer with Annexin V-FITC and propidium iodine (PI) staining as well as fluorescence microscopy with Hoechst 33258 staining. Intracellular reactive oxygen species (ROS) level was measured by flow cytometer with 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) staining.

RESULTS

The cytotoxicity of MB-mediated SDT on HO-8910 cells after MB-mediated SDT was significantly higher than those of other treatments including ultrasound alone, MB alone and sham treatment. Flow cytometric analysis showed a significant increase in the early and late apoptotic cell populations by MB-mediated SDT of HO-8910 cells. Nuclear condensation and increased ROS levels were also found in HO-8910 cells treated by MB-mediated SDT.

CONCLUSIONS

Our findings demonstrated that MB-mediated sonodynamic action significantly induced apoptosis of HO-8910 cells and an increase in intracellular ROS level. This indicates that apoptosis is an important mechanism of cell death induced by MB-mediated SDT. Thus, MB-mediated SDT might be a potential therapeutic strategy for combating ovarian cancer.

Ultrasound induces cellular destruction of nasopharyngeal carcinoma cells in the presence of curcumin

OBJECTIVES

Curcumin, a natural pigment from the traditional Chinese herb, has shown promise as an efficient enhancer of ultrasound. The present study aims to investigate ultrasound-induced cellular destruction of nasopharyngeal carcinoma cells in the presence of curcumin in vitro.

METHODS

Nasopharyngeal carcinoma cell line CNE2 cells were incubated by 10μm curcumin and then were treated by ultrasound for 8s at the intensity of 0.46W/cm(2). Cytotoxicity was evaluated using MTT assay and light microscopy. Mitochondrial damage was analyzed using a confocal laser scanning microcopy with Rhodamine 123 and ultrastructural changes were observed using a transmission electron microscopy (TEM).

RESULTS

MTT assay showed that cytotoxicity induced by ultrasound treatment alone and curcumin treatment alone was 18.16±2.37% and 24.93±8.30%, respectively. The cytotoxicity induced by the combined treatment of ultrasound and curcumin significantly increased up to 86.67±7.78%. TEM showed that microvillin disappearance, membrane blebbing, chromatin condensation, swollen mitochondria, and mitochondrial myelin-like body were observed in the cells treated by ultrasound and curcumin together. The significant collapse of mitochondrial membrane potential (MMP) was markedly observed in the CNE2 cells after the combined treatment of curcumin and ultrasound.

CONCLUSIONS

Our findings demonstrated that ultrasound sonication in the presence of curcumin significantly killed the CNE2 cells and induced ultrastructural damage and the dysfunction of mitochondria, suggesting that ultrasound treatment remarkably induced cellular destruction of nasopharyngeal carcinoma cells in the presence of curcumin.

Study on the interaction between hematoporphyrin monomethyl ether and DNA and the determination of hematoporphyrin monomethyl ether using the resonance light scattering technique

The interaction between photosensitizer anticancer drug hematoporphyrin monomethyl ether (HMME) and ctDNA has been studied based on the decreased resonance light scattering (RLS) phenomenon. The RLS, UV-vis and fluorescence spectra characteristics of the HMME-ctDNA system were investigated. Besides, the phosphodiesters quaternary ammonium salt (PQAS), a kind of new gemini surfactant synthesized recently, was used to determine anticancer drug HMME based on the increasing RLS intensity. Under the optimum assay conditions, the enhanced RLS intensity was proportional to the concentration of HMME. The linear range was 0.8-8.4microgmL(-1), with correlation coefficient R(2)=0.9913. The detection limit was 0.014microgmL(-1). The human serum samples and urine samples were determined satisfactorily, which proved that this method was reliable and applicable in the determination of HMME in body fluid. The presented method was simple, sensitive and straightforward and could be a significant method in clinical analysis.

Hematoporphyrin monomethyl ether enhances the killing of ultrasound on osteosarcoma cells involving intracellular reactive oxygen species and calcium ion elevation

OBJECTIVE

The present study aims to investigate the possible mechanisms of hematoporphyrin monomethyl ether (HMME) enhancing the cytotoxicity of ultrasound in osteosarcoma cells.

METHODS

Osteosarcoma cell line UMR-106 was treated by HMME and ultrasound radiation, with the HMME concentration kept at 20 μg/mL and ultrasound radiation for 10 seconds at the intensity of 0.5 W/cm². Cell proliferation was investigated at 12, 24, 36, and 48 hours using MTT assay after ultrasound and HMME treatment. Ultrastructural morphology was observed using transmission electron microscopy (TEM). Intracellular reactive oxygen species (ROS) was measured using a flow cytometry with DCFH-DA staining and intracellular free calcium ion (Ca(2+)) with Fluo-3-AM staining.

RESULTS

The UMR-106 cells proliferated rapidly in the sham radiation and HMME treatment alone group, but ultrasound-treated cells and HMME-ultrasound-treated cells proliferated slowly. There was a significant difference between HMME-ultrasound treatment and the controls, including ultrasound radiation, HMME treatment alone, and sham radiation (P < .05). TEM showed endoplasmic reticulum and mitochondrial swelling in the ultrasound-treated cells, and more cells presented apoptosis and necrosis after treatment with ultrasound and HMME together. Intracellular ROS and Ca(2+) in the cells increased more significantly after both ultrasound and HMME treatment than after ultrasound treatment alone.

CONCLUSIONS

HMME could effectively enhance the inhibition effect of ultrasound on osteosarcoma cells. Intracellular ROS and Ca(2+) in the UMR-106 cells increased more significantly after the treatment of HMME and ultrasound together, indicating that the enhancement of HMME on ultrasound cytotoxicity to osteosarcoma cells possibly involves both intracellular ROS and Ca(2+) elevation.

Ultrasound-Induced Cell Death of Nasopharyngeal Carcinoma Cells in the Presence of Curcumin

Objectives. Curcumin, a natural pigment from a traditional Chinese herb, has been attracting extensive attention. The present study aims to investigate cell death of nasopharyngeal carcinoma (NPC) cells induced by ultrasound sonication in the presence of curcumin in vitro. Methods. The NPC cell line CNE2 was chosen as a tumor model, and curcumin concentration was kept constant at 10 µM while the cells were subjected to ultrasound exposure for 8 s at an intensity of 0.46 W/cm2. Cell death was evaluated using flow cytometry with annexinV-FITC and propidium iodine staining, and nuclear staining with Hoechst 33258. Mitochondrial membrane potential and intracellular reactive oxygen species (ROS) were analyzed using flow cytometry with rhodamine 123 and dichlorodihydrofluorecein diacetate staining. Results. Flow cytometry showed that the combination of ultrasound and curcumin significantly increased the necrotic or late apoptotic rate by up to 31.37% compared with the controls. Nuclear condensation was observed in the nuclear staining, and collapse of ΔΨm and ROS increase were found in the CNE2 cells after the treatment with curcumin and ultrasound. Conclusions. The findings demonstrate that the presence of curcumin significantly enhances the ultrasound-induced cell death and ROS level, and induces the collapse of ΔΨm, suggesting that ultrasound sonication can increase the cell death of NPC cells in the presence of curcumin and that the treatment using curcumin and ultrasound together is a potential therapeutic modality in the management of malignant tumors.