Interleukin-12 (IL-12) has long been considered to be effective in triggering an anticancer immune response, however, the dosage has been limited by potential systemic immunotoxicity. Since focused ultrasound (FUS) has been confirmed to temporally and locally open the blood–brain barrier (BBB), the purpose of this study was to elucidate the possibility of combining FUS-induced BBB opening with IL-12 delivery to enhance the anticancer immunological response for glioma treatment. FUS energy combined with microbubble administration was delivered transcranially to open BBB, and C-6 glioma rats were used in this study. The efficacy in inducing BBB opening and the corresponding immunological response were primarily evaluated in normal animals. The anticancer immune-triggering chemokine, IL-12, was intraperitoneally administered during the treatment phase to evaluate the effect of immunological response on tumor progression. Glioma animals were sub-grouped to evaluate the effect of the immune response in suppressing glioma when IL-12 was combined with FUS-induced BBB opening. We performed flow cytometry to verify consequent immune cell population changes of peripheral/tissue lymphocytes as well as macrophages from the animals. Brain sections of sacrificed animals were also used for histological and immunohistochemical analysis. IL-12 level among experimental groups were measured via ELISA analysis. We also analyzed survival and followed tumor progression in vivo via T2-weighted magnetic resonance imaging. FUS-induced BBB opening had no obvious effect on the T lymphocytes population in normal animals, either in the brain or systemically. Yet, it triggered mild changes in the tumor-infiltrating lymphocyte (TIL) population, particularly in numbers of CD3+CD8+ cytotoxic T lymphocytes (CTLs) in the tumor region. IL-12 administration triggered a profound increase in all TIL populations, including CD3+CD4+ T helper cells (Th), CTL, and CD4+CD25+ regulatory T cells (Treg), but combined FUS-BBB opening with IL-12 administration produced the most significant IL-12 increase, CTL increase and CTL/Treg ratio increase, thus contributing to the most significant suppression of tumor progression and increased animal survival. This study provides evidence that FUS-BBB opening can enhance immune-modulating agent delivery to the brain, which improve the anticancer immune response in brain tumor treatment.

Background: Glioblastoma multiforme (GBM) is the most aggressive type of glioma and carries the poorest chances of survival. There is therefore an urgent need to understand the mechanisms of glioma tumorigenesis and develop or improve therapeutics. The aim of this study was to assess the possible prognostic value of cyclin-dependent kinase 6 (CDK6) and the effects of microRNA-495 (miR-495) manipulation on CDK6 expression and cell survival in glioma cells. Methods: Analyses of clinical specimens from GBM patients were used. Expression of CDK6 was analyzed by real-time polymerase chain reaction (RT-PCR), Western blotting, and immunohistochemistry. Expression of CDK6 was also analyzed after over-expression of miR-495 in T98 cells; both cell proliferation and RB phosphorylation were examined. Cell proliferation, cell cycle distribution, and RB phosphorylation were also examined after knockdown of CDK6 in U87-MG and T98 cells. Results: Analyses of clinical specimens from GBM patients identified that CDK6 is significantly expressed in gliomas. CDK6 antigen expression was higher in tumor cores and margins than in adjacent normal brain tissues, and higher levels of CDK6 expression in the tumor margin correlated with decreased survival. Over-expression of miR-495 in T98 cells downregulated the expression of CDK6 and inhibited retinoblastoma phosphorylation, and knockdown of CDK6 in U87-MG and T98 cells by siRNAs resulted in cell cycle arrest at the G1/S transition and inhibition of cell proliferation. Conclusions: This study revealed miR-495 is down-regulated in glioma tissues. Furthermore, miR-495 regulated CDK6 expression and involved in glioma cell growth inhibition, which indicated the possible role of miR-495 in tumor progression.

The piezoresistive characteristics of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) pressure sensors with inter-digitated (IDE) and cross-point electrode (CPE) structures have been investigated. A small variation of the resistance of the pressure sensors with IDE without bottom indium-tin-oxide (b-ITO) film and with CPE structures was observed owing to the single carrier-conducting pathway. For the IDE pressure sensors with b-ITO, the piezoresistive characteristics at low and high pressure were similar to those of the pressure sensors with IDE without b-ITO and with CPE structures, respectively, leading to increased piezoresistive pressure sensitivity as the PEDOT:PSS film thickness decreased. A maximum sensitivity of more than 42 kΩ/Pa was achieved. When the normal pressure was applied, the increased number of conducting points or the reduced distance between the PEDOT oligomers within the PEDOT:PSS film resulted in a decrease of the resistance. The piezoresistive pressure sensors with a single carrier-conducting pathway, i.e., IDE without b-ITO and CPE structures, exhibited a small relaxation time and a superior reversible operation, which can be advantageous for fast piezoresistive response applications.

Sonodynamic therapy (SDT) is a novel tumor treatment that combines biosafe sonosensitizers and noninvasive focused ultrasound to eradicate solid tumors. Sonosensitizers such as 5-aminolevulinic acid and fluorescein have great potential in tumor treatment. Here, rodent subcutaneous and brain tumor models were used to evaluate the treatment effect of both 5-ALA- and fluorescein-mediated SDT. The subcutaneous tumor growth rates of both SDT groups were significantly inhibited compared with that of the control groups. For intracranial tumors, 5-ALA-SDT treatment significantly inhibited brain tumor growth, while fluorescein-SDT exerted no therapeutic effect in animals. The distribution of fluorescein in the brain tumor region underwent further assessment. Seven days post tumor implantation, experimental animals received fluorescein and were sacrificed for brain specimen collection. Analysis of the dissected brains revealed no fluorescence signals, indicating an absence of fluorescein accumulation in the early-stage glioma tissue. These data suggest that the fluorescein-SDT treatment response is closely related to the amount of accumulated fluorescein. This study reports the equivalent effects of 5-ALA and fluorescein on the treatment of somatic tumors. For orthotopic brain tumor models, tumor vascular permeability should be considered when choosing fluorescein as a sonosensitizer. In conclusion, both fluorescein and 5-ALA are safe and effective SDT sonosensitizers, and the tumor microenvironment and pathologic type should be considered in the selection of adequate sonosensitizers.

BACKGROUND AND OBJECTIVES: Combining focused ultrasound (FUS)–induced blood-brain barrier opening with bevacizumab (BEV) has demonstrated survival benefits in preclinical models. This study aimed to evaluate the safety and feasibility of repeated FUS-BEV treatments in patients with recurrent glioblastoma and to explore imaging and serum biomarkers in relation to disease status. METHODS: This was a prospective, single-arm, open-label pilot trial. The primary end point was 6-month progression-free survival (PFS). Disease progression was assessed according to the Response Assessment in Neuro-Oncology criteria by independent radiological review. Radiological response was evaluated using fluid-attenuated inversion-recovery sequences to compare FUS-exposed vs nonexposed regions. Plasma cell–free DNA (cfDNA) concentrations were measured before and after FUS treatment. RESULTS: Between July 2020 and August 2023, 6 patients received a median of 14.5 sessions of biweekly FUS-BEV (10 mg/kg). The median PFS was 11 months, with a 6-month PFS rate of 66.7%. The only FUS-related adverse event was transient scalp heating (grade 1; 1.9%). A fluid-attenuated inversion recovery normalization effect emerged within 1 month after treatment. Plasma cfDNA increased significantly post-FUS, with total cfDNA rising 2.03 ± 0.76-fold, EGFR cfDNA 1.77 ± 0.76-fold, and HMBS cfDNA 1.68 ± 0.66-fold. CONCLUSION: Repeated FUS-BEV treatment is safe and feasible in patients with recurrent glioblastoma. Randomized controlled trials are warranted to confirm its therapeutic efficacy and validate imaging and liquid biopsy biomarkers.