樋田 泰浩

BACKGROUND: Inflammation is one of the hallmarks of cancer and is associated with tumor growth. Tumor endothelial cells (TECs) demonstrate inflamed phenotypes. Endothelial inflammation initiates thrombus formation, which is the second cause of cancer-related deaths. Epigallocatechin-3-O-gallate (EGCG), a natural compound in green tea, has demonstrated an anti-inflammatory effect. However, the tumor progression inhibition effect of EGCG by targeting TEC inflammation remains unclear. This study addresses the anti-tumor effect of EGCG, especially its anti-inflammatory role in TECs. METHODS: In vitro, the effect of EGCG on TECs were studied using real-time quantitative PCR and immunofluoresence to analyza gene and protein expression. In vivo, a cyclic RGD liposome delivery system (MEND) was employed to efficiently deliver EGCG to TECs in tumor-bearing mice. RESULTS: In vitro, EGCG significantly reduces inflammatory cytokine expression, including tumor necrosis factor-α, interleukin-6, IL-8, and IL-1β through NF-κB signaling inhibition. Additionally, von Willebrand factor reduction in TECs, which is involved in platelet adhesion and thrombosis formation, was analyzed. Our results revealed that EGCG-MEND significantly inhibited TEC inflammation and thrombus formation in tumors. Additionally, EGCG-MEND improved tumor immunity by reducing programmed death-ligand 1 expression and promoting high endothelial venule formation by recruiting CD8+ T cells. CONCLUSION: Our results indicate the anti-tumor potential of EGCG-MEND in normalizing the inflammatory immune microenvironment and inhibiting thrombosis by targeting TEC.

When performing thoracoscopic partial resections of nonpalpable lung tumors such as ground-glass opacities (GGOs) and small tumors, detecting the location of the lesion and assessing the resection margins can be challenging. We have developed a novel method to ease this difficulty, the One-stop Solution for a nonpalpable lung tumor, Marking, Resection, and Confirmation of the surgical margin in a Hybrid operating room (OS-MRCH), which uses a hybrid operating room wherein the operating table is seamlessly integrated with cone-beam computed tomography (CBCT). We performed the OS-MRCH method on 62 nodules including primary lung cancer presenting with GGO. Identification of the lesion and confirmation of the margin were performed in 58 of the cases, while nodules were detected in all. The frequency of computed tomography (CT) scans performed prior to resection was one time in 51 cases, two times in eight cases, and ≥3 times in three cases. Additional resection was performed in two cases. The median operative time was 85.0 minutes, and the median pathological margin was 11.0 mm. The key advantages of this method are that all surgical processes can be completed in a single session, specialized skill sets are not required, and it is feasible to perform in any facility equipped with a hybrid operating room. To overcome its disadvantages, such as longer operating time and limited patient positioning, we devised various methods for positioning patients and for CT imaging of the resected specimens. OS-MRCH is a simple, useful, and practical method for performing thoracoscopic partial resection of nonpalpable lung tumors.

Thrombosis is a well-known cardiovascular disease (CVD) complication that has caused death in many patients with cancer. Oral bacteria have been reported to contribute to systemic diseases, including CVDs, and tumor metastasis. However, whether oral bacteria-induced thrombosis induces tumor metastasis remains poorly understood. In this study, the cariogenic oral bacterium Streptococcus mutans was used to examine thrombosis in vitro and in vivo. Investigation of tumor metastasis to the lungs was undertaken by intravenous S. mutans implantation using a murine breast cancer metastasis model. The results indicated that platelet activation, aggregation, and coagulation were significantly altered in S. mutans-stimulated endothelial cells (ECs), with elevated neutrophil migration, thereby inducing thrombosis formation. Streptococcus mutans stimulation significantly enhances platelet and tumor cell adhesion to the inflamed ECs. Furthermore, S. mutans-induced pulmonary thrombosis promotes breast cancer cell metastasis to the lungs in vivo, which can be reduced by using aspirin, an antiplatelet drug. Our findings indicate that oral bacteria promote tumor metastasis through thrombosis formation. Oral health management is important to prevent CVDs, tumor metastasis, and their associated death.