Low-frequency ultrasound-mediated microvessel disruption combined with docetaxel to treat prostate carcinoma xenografts in nude mice: A novel type of chemoembolization

Social Distress among Cancer Patients: Differential Effects of Risk Factors and Attenuating Role of Culturally Specific Social Support

Introduction: We investigated the association between social distress or toxicity and patients' clinical conditions, demographic characteristics, and social support and networks, and whether this association differs along the distribution of patients' distress levels. This study included 156 patients treated at King Abdulaziz Medical City, Riyadh, Saudi Arabia. Methods: We used the previously validated Social Toxicity Assessment Tool in Cancer (STAT-C) to assess cancer patients' distress. We analyzed distress level, the outcome variable of interest, and covariates to show distribution and identify associations. We then used logistic quantile regression for bounded outcomes to assess the association between social distress or toxicity and patients' clinical conditions, demographic characteristics, and social support and network. As an extension, we examined the interaction between disease status and social support, focusing on the moderating role of social support in attenuating the impact of disease status on social distress. Results: The median age of the patients was 51.2 (SD = 21.4, range 22 to 89), with 48.1% being older than 50 years. Of the 156 cancer patients analyzed, 82 (52.6%) were classified as burdened, and 50% of those with uncontrolled disease status were socially distressed. However, there were more socially distressed patients diagnosed within a year and patients undergoing treatment. There was a greater number of patients who shared their diagnosis with family, colleagues, and neighbors with social distress. The odds of suffering from social distress were higher in younger patients (50 years or younger) than in older patients. Social distress was lower in patients who underwent combined chemotherapy, surgery, and radiation compared with patients who received a single treatment regimen (OR = 0.65, CI, -0.820 to -0.036, p = 0.033). The odds of social distress were 67% higher in patients diagnosed within one year than in patients diagnosed more than one year prior (OR = 1.664, CI, 0.100-0.918, p = 0.015). Patients with uncontrolled disease conditions who shared their diagnosis and treatment with social networks were 48% less likely to experience social distress. Thus, sharing cancer diagnoses with social networks has a statistically significant moderating effect by attenuating the impact of disease status on social distress. Conclusion: Understanding the risk factors for social distress may be important for cancer management. Additionally, identifying the moderating role that patients' sharing of cancer diagnoses in social networks plays in attenuating the impact of disease status on social distress may provide healthcare providers with valuable insights for holistic culture-specific care.

Low-frequency ultrasound irradiation increases paclitaxel-induced sarcoma cells apoptosis and facilitates the transmembrane delivery of drugs

Sarcoma is a malignant tumor derived from interstitial tissues and requires comprehensive treatment including chemotherapy. Paclitaxel (PTX) is an active agent against sarcoma, but its effect is not sufficiently acceptable and needs to be improved. Low-frequency ultrasound (LFU) has been documented to improve the efficacy of drugs by inducing reversible changes in membrane permeability; however, the effects of the combined use of LFU and PTX for sarcoma tumors remain unclear and warrant further investigation. We investigated the effects of 30 kHz LFU treatment combined with PTX on sarcoma cells A-204 and HT-1080 by analyzing in vitro apoptosis and cell growth inhibition rates, and determined their antitumor effects by examining tumor weights with or without LFU in the S180 sarcoma xenograft model. Drug concentrations in the subcutaneous tumors were measured using high performance liquid chromatography (HPLC). LFU combined with PTX significantly induced cell apoptosis, and blocked the cell cycle of sarcoma cells in G2/M phase, and furthermore, inhibited the activation of JAK2/STAT3 signaling pathway. Meanwhile, LFU combined with PTX inhibited the expression of PD-L1 in vitro, suggesting the potential of enhanced antitumor immunity by this treatment. LFU combined with PTX significantly inhibited the growth of S180 tumors transplanted subcutaneously in Institute of Cancer Research (ICR) mice, and its enhanced effect may be associated with increased local concentrations of PTX in tumor tissues in vivo, with no significant adverse subsequences on body weight observed. We conclude that the combination of LFU and PTX has synergistic antitumor effects and is a candidate for subcutaneous treatment of sarcoma by further increasing the intracellular concentration of PTX.

Ultrasound Therapy, Chemotherapy and Their Combination for Prostate Cancer

Prostate cancer is the second leading cause of cancer death in men. Its current treatment includes various physical and chemical approaches for the localized and advanced prostate cancer [e.g. metastatic castrate resistant prostate cancer (mCRPC)]. Although many new drugs are now available for prostate cancer, none is suitable for local treatment that can reduce adverse effects often associated with the current physical treatment. Of the drugs approved by FDA for mCRPC, the best mean improvement in overall survival is only about 4.8 months. Therefore, there is a need for improved treatment approaches for prostate cancer, especially drug-resistant cancer.

Ultrasound therapy represents a useful new physical approach for the drug-resistant cancer treatment by facilitating the entry of the related chemotherapy drug into the target cancer cells. There are two versions of ultrasound: High Intensity Focused Ultrasound (HIFU) and Low Intensity Pulsed Ultrasound (LIPUS). HIFU has been a promising treatment option for prostate cancer due to its noninvasiveness and various biological effects on cancer tissue. It has been approved for the treatment of cancer and in recent years there have been numerous findings suggesting HIFU can reduce cancer cell viability and possibly reverse the spread of cancerous tumors. LIPUS is currently being studied as an alternative treatment option for prostate cancer. Preliminary studies have found LIPUS to reduce cancer cell viability without the side effects seen in HIFU. Reversible cell membrane damage caused by LIPUS could allow increased uptake of anticancer drugs, enhancing cytotoxicity and death of cancer cells. In this way, a low dose of anticancer drug is more effective toward cancer cells while there is less damage to normal cells. The combination of LIPUS with certain chemotherapeutic agents can be an exciting physical-chemical combination therapy for prostate cancer. This review will focus on this topic as well as the clinical use of HIFU to provide an understanding of their current use and future potential role for prostate cancer therapy.

Improving the Therapeutic Effect of Ultrasound Combined With Microbubbles on Muscular Tumor Xenografts With Appropriate Acoustic Pressure

Ultrasound combined with microbubbles (USMB) is a promising antitumor therapy because of its capability to selectively disrupt tumor perfusion. However, the antitumor effects of repeated USMB treatments have yet to be clarified. In this study, we established a VX2 muscular tumor xenograft model in rabbits, and performed USMB treatments at five different peak negative acoustic pressure levels (1.0, 2.0, 3.0, 4.0, or 5.0 MPa) to determine the appropriate acoustic pressure. To investigate whether repeated USMB treatments could improve the antitumor effects, a group of tumor-bearing rabbits was subjected to one USMB treatment per day for three consecutive days for comparison with the single-treatment group. Contrast-enhanced ultrasonic imaging and histological analyses showed that at an acoustic pressure of 4.0 MPa, USMB treatment contributed to substantial cessation of tumor perfusion, resulting in severe damage to the tumor cells and microvessels without causing significant effects on the normal tissue. Further, the percentages of damaged area and apoptotic cells in the tumor were significantly higher, and the tumor growth inhibition effect was more obvious in the multiple-treatment group than in the single USMB treatment group. These findings indicate that with an appropriate acoustic pressure, the USMB treatment can selectively destroy tumor vessels in muscular tumor xenograft models. Moreover, the repeated treatments strategy can significantly improve the antitumor effect. Therefore, our results provide a foundation for the clinical application of USMB to treat solid tumors using a novel therapeutic strategy.

Advances in low-frequency ultrasound combined with microbubbles in targeted tumor therapy

The development of low-frequency ultrasound imaging technology and the improvement of ultrasound contrast agent production technology mean that they play an increasingly important role in tumor therapy. The interaction between ultrasound and microbubbles and their biological effects can transfer and release microbubbles carrying genes and drugs to target tissues, mediate the apoptosis of tumor cells, and block the embolization of tumor microvasculature. With the optimization of ultrasound parameters, the development of targeted microbubbles, and the emergence of various composite probes with both diagnostic and therapeutic functions, low-frequency ultrasound combined with microbubble contrast agents will bring new hope for clinical tumor treatment.

Effect of docetaxel-loaded lipid microbubble in combination with ultrasound-triggered microbubble destruction on the growth of a gastric cancer cell line

Although gastric cancer therapy has been improved, more efficient treatment strategies still need to be developed. In the present study, a docetaxel (DOC)-loaded lipid microbubble (DLLD) was prepared and the effect of DLLD combined with ultrasound-triggered microbubble destruction (UTMD) on the growth of a gastric cancer cell line was investigated. The following four groups were included in the present study: Control, DOC, DLLD and DLLD plus UTMD. The determined entrapment efficiency of DLLD is 76±3.5%. The present study demonstrated that treatment with DLLD plus UTMD could significantly inhibit the growth of the cultured gastric cancer cell line BGC-823 via arresting the cell cycle in G₂/M phase, inhibiting cell DNA synthesis, promoting cell apoptosis and disrupting mitochondrial membrane potential, as compared with treatment with DOC or DLLD alone. Furthermore, the expression of p53, p21 and Bax were identified to be significantly upregulated, while that of Bcl-2 was significantly downregulated in the DLLD plus UTMD group. Therefore, treatment with DLLD plus UTMD was more efficient in inhibiting cell proliferation and inducing cell apoptosis in the gastric cancer cell line, when compared with treatment with DOC or DLLD alone, suggesting that DLLD plus UTMD could serve as a promising strategy for the treatment of gastric cancer.

Spatially Uniform Tumor Treatment and Drug Penetration by Regulating Ultrasound with Microbubbles

Tumor microenvironment has different morphologies of vessels in the core and rim regions, which influences the efficacy of tumor therapy. Our study proposed to improve the spatial uniformity of the antivascular effect and drug penetration within the tumor core and rim in combination therapies by regulating ultrasound-stimulated microbubble destruction (USMD). Focused ultrasound at 2 MHz and lipid-shell microbubbles (1.12 ± 0.08 μm, mean ± standard deviation) were used to perform USMD. The efficiency of the antivascular effect was evaluated by intravital imaging to determine the optimal USMD parameters. Tumor perfusion and histological alterations in the tumor core and rim were used to analyze the spatial uniformity of the antivascular effect and liposomal-doxorubicin (5 mg/kg) penetration in the combination therapy. Tumor vessels of specific sizes were disrupted by regulating USMD: vessels with sizes of 11 ± 3, 14 ± 5, 19 ± 7, and 23 ± 10 μm were disrupted by stimulation at acoustic pressures of 3, 5, 7, and 9 MPa, respectively (each p < 0.05). The effective treatment time of USMD (at 2 × 10⁷ microbubbles/mouse, 7 MPa, and three cycles) was 60-120 min, which resulted in the disruption of 21-44% of vessels smaller than 50 μm. The reductions in perfusion and vascular density after combination therapy did not differ significantly between the tumor core and rim. This study found that regulating USMD can result in homogeneous antivascular effects and drug penetration within tumors and thereby improve the efficacy of combination therapies.

UTMD-Promoted Co-Delivery of Gemcitabine and miR-21 Inhibitor by Dendrimer-Entrapped Gold Nanoparticles for Pancreatic Cancer Therapy

Conventional chemotherapy of pancreatic cancer (PaCa) suffers the problems of low drug permeability and inherent or acquired drug resistance. Development of new strategies for enhanced therapy still remains a great challenge. Herein, we report a new ultrasound-targeted microbubble destruction (UTMD)-promoted delivery system based on dendrimer-entrapped gold nanoparticles (Au DENPs) for co-delivery of gemcitabine (Gem) and miR-21 inhibitor (miR-21i).

Methods: In this study, Gem-Au DENPs/miR-21i was designed and synthesized. The designed polyplexes were characterized via transmission electron microscopy (TEM), Gel retardation assay and dynamic light scattering (DLS). Then, the optimum exposure parameters were examined by an ultrasound exposure platform. The cellular uptake, cytotoxicity and anticancer effects in vitro were analyzed by confocal laser microscopy, spectra microplate reader, flow cytometry and a chemiluminescence imaging system. Lastly, the anticancer effects in vivo were evaluated by contrast-enhanced ultrasound (CEUS), hematoxylin and eosin (H&E) staining, TUNEL staining and comparison of tumor volume.

Results: The results showed that the Gem-Au DENPs/miR-21i can be uptake by cancer cells and the cellular uptake was further facilitated by UTMD with an ultrasound power of 0.4 W/cm² to enhance the cell permeability. Further, the co-delivery of Gem and miR-21i with or without UTMD treatment displayed 82-fold and 13-fold lower IC50 values than the free Gem, respectively. The UTMD-promoted co-delivery of Gem and miR-21i was further validated by in vivo treatment and showed a significant tumor volume reduction and an increase in blood perfusion of xenografted pancreatic tumors.

Conclusion: The co-delivery of Gem and miR-21i using Au DENPs can be significantly promoted by UTMD technology, hence providing a promising strategy for effective pancreatic cancer treatments.