Anticancer effect of novel platinum nanocomposite beads on oral squamous cell carcinoma cells.

Nanoparticles are used in industry and medicine, because of their physiochemical properties, such as size, charge, large surface area and surface reactivity. Recently, metal nanoparticles were reported to show cell toxicity on cancer cells. In this study, we focused novel platinum nanoparticles-conjugated latex beads (P2VPs), platinum nanocomposite (PtNCP) beads, and investigated the possibility to incorporate novel anti-cancer effect of these combined nanoparticles. Oral squamous cell carcinoma cell lines, HSC-3-M3 cells were injected subcutaneously into the back of nude mice to produce a xenograft model. PtNCP beads were injected locally and examined by measuring tumor volume and comparing pathological histology. PtNCP beads treatment suppressed tumor growth and identified increasing pathological necrotic areas, in vivo. PtNCP beads inhibited the cell viability of HSC-3-M3 cells in dose-dependent manner and induced the cytotoxicity with extracellular LDH value, in vitro. Furthermore, SEM images were morphologically observed in PtNCP beads-treated HSC-3-M3 cells. The aggregation of the PtNCP beads on the cell membrane, the destructions of the cell membrane and globular structures were observed in the SEM image. Our results indicated that a potential anti-cancer effect of the PtNCP beads, suggesting the possibility as a therapeutic tool for cancer cell-targeted therapy. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2281-2287, 2019.

Ky-2, a hybrid compound histone deacetylase inhibitor, regulated inflammatory response in LPS-driven human macrophages.

Histone deacetylase has attracted much attention as an epigenetic factor, and the modulation of histone and transcription factor acetylation status is important for regulating gene expression. Moreover, histone deacetylase inhibitors are involved in cellular growth and differentiation. In the present study, we examined the effects of Ky-2, a hybrid-compound HDAC inhibitor, on inflammatory reactions and the polarization of macrophages in vitro. Human monocyte-like THP-1 cells were polarized to macrophage-like cells using phorbol 12-myristate 13-acetate, and then polarized to M1 macrophages with LPS. Ky-2 inhibited HDAC2 expression and enhanced the acetylation of histone H3 in THP-1 cells. It also downregulated the expression of the IL-1ß-encoding gene and the LPS-induced phosphorylation of p38 mitogen-activated protein kinases in THP-1 cells. Moreover, the expression of nod-like receptor protein 3 and cleaved caspase-1 p20 was downregulated in Ky-2-treated THP-1 cells. In contrast, this agent upregulated the expression of IL-1ra in LPS-treated THP-1 cells. These results indicate that Ky-2-treatment downregulates the expression of the inflammatory cytokine, IL-1ß, in LPS-treated THP-1 cells, suggesting that Ky-2 might regulate M1 macrophage polarization through the suppression of inflammatory responses such as NLRP3 inflammasome activation.

Epidermal growth factor receptor-targeted sonoporation with microbubbles enhances therapeutic efficacy in a squamous cell carcinoma model.

Sonoporation is a drug and gene delivery system using ultrasonication that allows the intracellular delivery of foreign molecules that cannot enter cells under normal conditions. We previously reported that sonoporation with microbubbles (MBs) could achieve effective intracellular drug delivery to human gingival squamous carcinoma Ca9-22 cells. In this study, we developed anti-epidermal growth factor receptor (EGFR) antibody-conjugated MBs (EGFR-MBs) and evaluated their capacity to enhance anti-cancer drug toxicity in vitro and in vivo. We first assessed the effect of sonoporation with EGFR-MBs on Ca9-22 cells by the WST-8 assay, flow cytometry and Hoechst's staining in vitro. Sonoporation and EGFR-MB had a strong cytotoxic effect on Ca9-22 cells with low-dose bleomycin. Furthermore, bleomycin delivery using sonoporation with EGFR-MBs remarkably increased the number of apoptotic cells. We next examined the effect of EGFR-MBs in a murine squamous cell carcinoma model. Bleomycin delivery by sonoporation with EGFR-MBs exhibited remarkable antitumor activity. Together, our results show that EGFR-MBs and ultrasound treatment increases the efficacy and specificity of intracellular drug uptake, suggesting this could be a novel drug-targeting modality for oral squamous cell carcinoma chemotherapy treatment.

Predictability and accuracy of maxillary repositioning during bimaxillary surgery using a three-dimensional positioning technique.

OBJECTIVE: The purpose of this retrospective study was to evaluate the predictability and accuracy of maxillary repositioning during bimaxillary surgery using a three-dimensional positioning technique. STUDY DESIGN: Twenty-six adult patients who underwent bimaxillary surgery requiring high superior maxillary impactions were divided into 2 groups. In group A, a three-dimensional positioning technique during maxillary repositioning was used along with an intermediate occlusal splint. In group B, only an intermediate occlusal splint with internal reference points was used. Both groups had measurements from predictive tracings compared to postoperative cephalograms to assess the accuracy of horizontal and vertical movements of the maxilla. RESULTS: Group A showed excellent correlation between the planned and actual maxillary positions in vertical and horizontal dimensions. In group B, the maxilla tended to move anteriorly than planned. CONCLUSIONS: Use of the three-dimensional positioning technique offered a predictive and accurate method for maxillary repositioning.

Mechanisms of G1 cell cycle arrest and apoptosis in myeloma cells induced by hybrid-compound histone deacetylase inhibitor.

OBJECTIVES: Histone deacetylase (HDAC) inhibitors are new therapeutic agents, used to treat various types of malignant cancers. In the present study, we investigated the effects of Ky-2, a hybrid-compound HDAC inhibitor, on the growth of mouse myeloma cells. MATERIALS AND METHODS: Myeloma cells, HS-72, P3U1, and mouse normal cells were used in this study. Effect of HDAC inhibitors on cell viability was determined by WST-assay and trypan blue assay. Cell cycle was analyzed using flow cytometer. The expression of cell cycle regulatory and the apoptosis associated proteins were examined by Western blot analysis. Hoechst's staining was used to detect apoptotic cells. RESULTS: Our findings showed that Ky-2 decreased the levels of HDACs, while it enhanced acetylation of histone H3. Myeloma cell proliferation was inhibited by Ky-2 treatment. Interestingly, Ky-2 had no cytotoxic effects on mouse normal cells. Ky-2 treatment induced G1-phase cell cycle arrest and accumulation of a sub-G1 phase population, while Western blotting analysis revealed that expressions of the cell cycle-associated proteins were up-regulated. Also, Ky-2 enhanced the cleavage of caspase-9 and -3 in myeloma cells, followed by DNA fragmentation. In addition, Ky-2 was not found to induce apoptosis in bcl-2 overexpressing myeloma cells. CONCLUSION: These findings suggest that Ky-2 induces apoptosis via a caspase-dependent cascade and Bcl-2-inhibitable mechanism in myeloma cells.

Ultrasonography for intraoperative determination of tumor thickness and resection margin in tongue carcinomas.

PURPOSE: Exact estimation of tumor thickness and the status of the resection margin in tongue carcinoma are important prognostic factors for local recurrence, subclinical nodal metastasis, and survival. This study aims to evaluate the accuracy of intraoral ultrasonography-guided measurement of tumor thickness and define an adequate intraoperative resection margin in squamous cell carcinomas of the tongue. MATERIALS AND METHODS: In this prospective study, 13 patients with presurgical, biopsy-proven, clinical T1N0 or T2N0 tongue squamous cell carcinomas who underwent a partial glossectomy were examined preoperatively with ultrasonography to assess tumor thickness under general anesthesia. Nine cases underwent resection by a conventional method, whereas we introduced elastic needles with a metal core to mark a deep surgical margin of 10 mm from the deepest tumor invasion front under ultrasonographic monitoring as a new technique in the remaining 4 cases. Each resected specimen was immediately immersed in gelatin solution while maintaining its original shape and orientation and was placed under refrigeration to solidify. Ultrasonographic observations of the gelatin-embedded specimens were performed from the superior surface of the gelatin block. RESULTS: Very fine ultrasonographic images of the resected specimen could be easily obtained without any special skills, and surgical clearance could be verified intraoperatively. The ultrasonographic tumor thickness measurements corresponded well with those of histologic sections, with a consistency ratio of 91.4% to 98.2% (Pearson correlation coefficient = 0.981, P < .05). CONCLUSION: Intraoperative ultrasonography is a reliable method to objectively evaluate tumor thickness and surgical margin clearance.

Targeted drug delivery system for oral cancer therapy using sonoporation.

Ultrasound-mediated destruction of microbubbles has been proposed as an innovative non-invasive drug delivery system for cancer therapy. We developed a specific drug delivery system for squamous cell carcinoma that uses sonoporation with the anti-epidermal growth factor receptor (EGFR) antibody. Administration of a low dose of bleomycin (BLM) by sonoporation with the anti-EGFR antibody produced a marked growth inhibition of Ca9-22 cells in vitro. In addition, scanning electron microscopic analysis revealed apparent surface deformation of Ca9-22 cells treated with sonoporation in the presence of the antibody. Interestingly, the population of apoptotic cells was remarkably increased when a low dose of BLM was delivered using sonoporation with the Fab fragment of the anti-EGFR antibody. These findings indicate that sonoporation with the Fab fragment makes it possible to administer drugs into cells more efficiently and specifically, suggesting a novel application for chemotherapy and gene therapy treatments for oral squamous cell carcinoma.

Delivery of cytolethal distending toxin B induces cell cycle arrest and apoptosis in gingival squamous cell carcinoma in vitro.

The cytolethal distending toxin (Cdt) from Actinobacillus actinomycetemcomitans consists of three proteins, CdtA, CdtB, and CdtC, which are responsible for cell cycle arrest and apoptosis. In the present study, local delivery systems of recombinant CdtB and CdtB-expressing plasmid were established using Ca9-22, human gingival squamous cell carcinoma cell line. When CdtB was delivered to Ca9-22 cells using a BioPORTER, a 32-kDa protein was detected by Western blotting, and G2 cell cycle arrest and apoptosis occurred. In addition, the CdtB delivered upregulated the expression of phosphorylated p53 and the cyclin-dependent kinase inhibitor p21(CIP1/WAF1) in Ca9-22 cells, suggesting that these intracellular molecules might contribute to the induction of G2 cell cycle arrest and apoptosis. When the CdtB-expressing plasmid was transfected into Ca9-22 cells by lipofection or electroporation, CdtB (32 kDa) was clearly detected. Further, TdT-mediated dUTP nick end labeling positive cells were observed after transfection of the CdtB-expressing plasmid. These findings indicated that delivery of the CdtB protein and transfection of the cdtB gene induced cell cycle arrest and apoptosis in Ca9-22 cells in vitro, and we conclude that it may be possible to induce apoptosis in human gingival squamous cell carcinoma by electroporation of the cdtB gene.