Low-intensity ultrasound enhances the anticancer activity of cetuximab in human head and neck cancer cells

Advances of ultrasound in tumor immunotherapy

Immunotherapy has become a revolutionary method for treating tumors, offering new hope to cancer patients worldwide. Immunotherapy strategies such as checkpoint inhibitors, chimeric antigen receptor T-cell (CAR-T) therapy, and cancer vaccines have shown significant potential in clinical trials. Despite the promising results, there are still limitations that impede the overall effectiveness of immunotherapy; the response to immunotherapy is uneven, the response rate of patients is still low, and systemic immune toxicity accompanied with tumor cell immune evasion is common. Ultrasound technology has evolved rapidly in recent years and has become a significant player in tumor immunotherapy. The introductions of high intensity focused ultrasound and ultrasound-stimulated microbubbles have opened doors for new therapeutic strategies in the fight against tumor. This paper explores the revolutionary advancements of ultrasound combined with immunotherapy in this particular field.

Low-intensity ultrasound combined with arsenic trioxide induced apoptosis of glioma via EGFR/AKT/mTOR

AIMS

This study aimed to explore whether low-intensity ultrasound (LIUS) combined with low-concentration arsenic trioxide (ATO) could inhibit the proliferation of glioma and, if so, to clarify the potential mechanism.

MAIN METHODS

The effects of ATO and LIUS alone or in combination on glioma were examined by CCK8, EdU, and flow cytometry assays. Western blot analysis was used to detect changes in expression of apoptosis-related proteins and their effects on the EGFR/AKT/mTOR pathway. The effects of ATO and LIUS were verified in vivo in orthotopic xenograft models, and tumor size, arsenic content in brain tissue, survival, and immunohistochemical changes were observed.

KEY FINDINGS

LIUS enhanced the inhibitory effect of ATO on the proliferation of glioma, and EGF reversed the proliferation inhibition and protein changes induced by ATO and LIUS. The anti-glioma effect of ATO combined with LIUS was related to downstream AKT/mTOR pathway changes caused by inhibition of EGFR activation, which enhanced apoptosis of U87MG and U373 cells. In vivo experiments showed significant increases in arsenic content in brain tissue, as well as decreased tumor sizes and longer survival times in the combined treatment group compared with other groups. The trends of immunohistochemical protein changes were consistent with the in vitro results.

SIGNIFICANCE

This study showed that LIUS enables ATO to exert anti-glioma effects at a safe dose by inhibiting the activation of EGFR and the downstream AKT/mTOR pathway to regulate apoptosis. LIUS in combination with ATO is a promising novel method for treating glioma and could improve patient prognosis.

Current status and future perspective of sonodynamic therapy for cancer

There is a tremendous need for prevention and effective treatment of cancer due to the associated morbidity and mortality. In this study, we introduce sonodynamic therapy (SDT), which is expected to be a new cancer treatment modality. SDT is a promising option for minimally invasive treatment of solid tumors and comprises three different components: sonosensitizers, ultrasound, and molecular oxygen. These components are harmless individually, but in combination they generate cytotoxic reactive oxygen species (ROS). We will explore the molecular mechanism by which SDT kills cancer cells, the class of sonosensitizers, drug delivery methods, and in vitro and in vivo studies. At the same time, we will highlight clinical applications for cancer treatment. The progress of SDT research suggests that it has the potential to become an advanced field of cancer treatment in clinical application. In this article, we will focus on the mechanism of action of SDT and its application to cancer treatment, and explain key factors to aid in developing strategies for future SDT development.

Potential Role of Individual and Combined Effects of T-2 Toxin, HT-2 Toxin and Neosolaniol on the Apoptosis of Porcine Leydig Cells

T-2 toxin usually co-occurs with HT-2 toxin and neosolaniol (NEO) in the grains and feed. Our previous studies found that T-2 toxin and its metabolites’ binary or ternary combination exposure to porcine Leydig cells (LCs) displayed synergism in certain range of dosage and cannot be predicted based on individual toxicity. However, the possible mechanism of these mycotoxins’ combined exposure to cell lesions remains unknown. Based on 50% cell viability, the mechanism of apoptosis in porcine Leydig cells was investigated after exposure to T-2, HT-2, NEO individual and binary or ternary combinations. Compared with control, the adenosine triphosphate (ATP) content decreased, reactive oxygen species (ROS) level increased, and mitochondrial membrane potential (MMP) decreased in all treated groups. Additionally, the cell apoptosis rates were significantly increased in test groups (p < 0.05), and the B-cell lymphoma 2 (Bcl-2) Associated X (Bax)/Bcl-2 ratio and the expression of caspase 3, caspase 8, cytochrome c (Cytc) in the treated group are all significantly higher than the control group. Moreover, the expression of Cytc and caspase 8 gene in NEO and T-2+NEO groups was significantly higher than that in other individual and combined groups. It can be concluded that the toxicities of T-2, HT-2, and NEO individually and in combination can induce apoptosis related to the oxidative stress and mitochondrial damage, and the synergistic effect between toxins may be greater than a single toxin effect, which is beneficial for assessing the possible risk of the co-occurrences in foodstuffs to human and animal health.

Identification of Three Autophagy-Related Long Non-Coding RNAs as a Novel Head and Neck Squamous Cell Carcinoma Prognostic Signature

Head and neck squamous cell carcinoma (HNSCC) has a poor prognosis. Considerable evidence indicates that autophagy and non-coding RNA play essential roles in the biological processes involved in cancers, but associations between autophagy-related long non-coding RNAs (lncRNAs) and HNSCC remain unclear. In the present study, HNSCC RNA sequences and autophagy-related gene data were extracted from The Cancer Genome Atlas database and the Human Autophagy Database. A total of 1,153 autophagy-related lncRNAs were selected via calculating Pearson’s correlation coefficient. Three prognosis-related autophagy lncRNAs were identified via univariate Cox regression, least absolute shrinkage and selection operator analysis, and multivariate Cox regression analysis. We also constructed a prognostic model based on these autophagy-related lncRNAs and evaluated its ability to accurately and independently predict the prognosis of HNSCC patients. The area under the curve (AUC) was 0.864 (3-year) and 0.836 (5-year), and our model can independently predict the prognosis of HNSCC. The prognostic value of the three autophagy lncRNAs was confirmed via analysis of samples from five databases. To further identify the functions of the three lncRNAs, a co-expression network was constructed and pathway analysis was performed. In that analysis the lncRNAs were correlated with 189 related genes and 20 autophagy-related genes, and these lncRNAs mainly involved homologous recombination, the Fanconi anemia pathway, the autophagy-related pathway, and immune-related pathways. In addition, we validated the expression levels of three lncRNAs and autophagy markers (ATG12, BECN1, and MAP1LC3B) based on TIMER, Oncomine, and HPA database analysis. Our results indicated that TTTY15 was increased in HPV positive and HPV negative HNSCC patients, and three autophagy markers were up-regulated in all HNSCCC patients. Lastly, association between three lncRNAs and autophagy markers was performed, and our results showed that TTTY15 and MIF-AS1 were associated with autophagy markers. Collectively, these results suggested that three autophagy-related lncRNAs have prognostic value in HNSCC patients.

Low‑intensity ultrasound enhances the chemosensitivity of hepatocellular carcinoma cells to cisplatin via altering the miR‑34a/c‑Met axis

Recently, the use of low-intensity ultrasound (LIUS) combined with chemotherapeutic agents is widely used in clinical practice, mainly for the treatment of cancer; however, the mechanisms as to how LIUS enhances the antitumor effects of these agents are not fully understood. The aim of the present study was to explore the synergistic antitumor effects and mechanisms of cisplatin (DDP) combined with LIUS (LIUS-DDP) in hepatocellular carcinoma (HCC). We reported that LIUS effectively enhanced Huh7 and HCCLM3 cell sensitivity to a low concentration of DDP. Reverse transcription-quantitative polymerase chain reaction analysis revealed that LIUS could increase the expression of microRNA-34a (miR-34a) in HCC cells following DDP treatment. In addition, LIUS-DDP significantly increased intracellular reactive oxygen species (ROS) levels in vitro, and the upregulation of miR-34a induced by LIUS-DDP was reversed by the ROS scavenger N-acetylcysteine, suggesting that LIUS upregulates the expression of miR-34a via production of ROS. In addition, knockdown of miR-34a in HCC cells significantly suppressed the synergistic effects of LIUS-DDP treatment. Conversely, overexpression of miR-34a enhanced these synergistic effects. The results of a dual-luciferase assay indicated that c-Met, a well-known oncogene, was a target of miR-34a. We also determined that LIUS-DDP treatment inhibited the expression of c-Met, possibly due to increased ROS production, which upregulated miR-34a expression. Furthermore, overexpression of c-Met reversed the synergistic effects of LIUS-DDP treatment. Our findings suggest that LIUS could enhance the chemosensitivity of HCC cells to DDP by altering the miR-34a/c-Met axis. Therefore, DDP combined with LIUS may be a potential therapeutic application for the clinical treatment of patients with HCC.

Suppression of human 8-oxoguanine DNA glycosylase (OGG1) augments ultrasound-induced apoptosis in cervical cancer cells

PURPOSE

Human 8-oxoguanine DNA glycosylase (OGG1) is a major base excision repair enzyme, and it was reported to suppress the activation of intrinsic apoptotic signaling pathway in response to oxidative stress. In this study, our aim was to investigate the effects of OGG1 downregulation on ultrasound-induced apoptosis in cervical cancer cells.

METHODS

OGG1 expression was silenced by shRNA in the cervical cancer SW756 and CaSki cells. Cell viability was evaluated by MTT assay after OGG1 knockdown following ultrasound treatment. Ultrasound-induced apoptosis was measured by Annexin V-FITC/propidium iodide. Intracellular reactive oxygen species (ROS) production and Ca(2+) concentration were detected using a fluorescent probe, 2',7'-dichlorofluorescin diacetate (DCFH-DA) and a green fluorescent dye fluo-4AM, respectively. Western blotting was used to analyze the expression of Bcl-2, Bax, cleaved caspase-3, and nuclear factor-κB p65 (NF-κB p65).

RESULTS

The results indicated that OGG1 knockdown did not suppress cell proliferation, but significantly augmented ultrasound-induced inhibitory effects on the cell viability, and increased ultrasound-induced early apoptosis and late apoptosis and necrosis in the SW756 and CaSki cells when exposure to ultrasound (1MHz) at 1.5W/cm(2) for 30 and 60s. OGG1 knockdown significantly increased intracellular ROS production and Ca(2+) concentration after incubation of 6, 24, and 48h post-ultrasound treatment. The downregulation of Bcl-2 protein and the upregulation of Bax, cleaved caspase-3, and NF-κB p65 protein levels were observed in the shRNA-OGG1 cells and mock-shRNA cells, but no significant change of these protein levels was found between of them.

CONCLUSIONS

These results indicate that downregulation of OGG1 expression can augment ultrasound-induced apoptosis in cervical cancer cells, which suggests that OGG1 suppression might provide a new insight for ultrasound-induced therapeutic effects on cervical cancer treatment.

Intra-tumor AvidinOX allows efficacy of low dose systemic biotinylated Cetuximab in a model of head and neck cancer

For locally advanced and metastatic head and neck squamous cell carcinoma (HNSCC), the current clinical use of Cetuximab in chemo/radiotherapy protocols is often associated to severe systemic toxicity. Here we report in vitro data in human FaDu pharynx SCC cells, showing that inactive concentrations of biotinylated Cetuximab (bCet) become active upon anchorage to AvidinOX on the surface of tumor cells. AvidinOX-anchored bCet induces apoptosis and DNA damage as well as specific inhibition of signaling, degradation and abrogation of nuclear translocation of EGFR. In the mouse model of FaDu cancer, we show that intra-tumor injection of AvidinOX allows anti-tumor activity of an otherwise inactive, intraperitoneally delivered, low dose bCet. Consistently with in vitro data, in vivo tumor inhibition is associated to induction of apoptosis, DNA damage and reduced angiogenesis. AvidinOX is under clinical investigation for delivering radioactive biotin to inoperable tumors (ClinicalTrials.gov NCT02053324) and present data support its use for the local treatment of HNSCC in combination with systemic administration of low dose bCet.

Recent advances in head and neck squamous cell carcinoma--a review

The current review presents the results of the most recent studies performed on different aspects of human head and neck squamous cell carcinoma, including radiosensitivity induction, efficiency improvement of monoclonal antibodies using low-intensity ultrasound, chemical compounds such as toll-like receptor (TLC) agonists, dasatinib, resveratrol and niclosamide, nuclear inhibition of cancer using STAT3 decoy oligonucleotide, efficiency of anti-EGFR monoclonal antibodies in detection of head and neck cancers and other related issues.

Ultrasound induced cancer immunotherapy

Recently, the use of ultrasound (US) has been shown to have potential in cancer immunotherapy. High intensity focused US destruction of tumors may lead to immunity forming in situ in the body by immune cells being exposed to the tumor debris and immune stimulatory substances that are present in the tumor remains. Another way of achieving anti-cancer immune responses is by using US in combination with microbubbles and nanobubbles to deliver genes and antigens into cells. US leads to bubble destruction and the forces released to direct delivery of the substances into the cytoplasm of the cells thus circumventing the natural barriers. In this way tumor antigens and antigen-encoding genes can be delivered to immune cells and immune response stimulating genes can be delivered to cancer cells thus enhancing immune responses. Combination of bubbles with cell-targeting ligands and US provides an even more sophisticated delivery system whereby the therapy is not only site specific but also cell specific. In this review we describe how US has been used to achieve immunity and discuss the potential and possible obstacles in future development.