MicroRNA-4461 derived from bone marrow mesenchymal stem cell exosomes inhibits tumorigenesis by downregulating COPB2 expression in colorectal cancer.

Colorectal cancer (CRC) is one of the main cause of cancer-related deaths. It's reported that bone marrow mesenchymal stem cells (BMSCs) affects tumor development through secreting exosomes. This study aims to investigate the function of BMSCs-derived exosome miR-4461 in CRC. The results of qRT-PCR showed that miR-4461 expression in DLD1, HCT116 and SW480 CRC cells and CRC tissues was lower than that in FHC cells and normal tissues, respectively. And COPB2 mRNA expression was negatively correlated with miR-4461. Western blot was used to detect COPB2 protein expression. Dual-luciferase reporter assay results revealed that miR-4461 targeted COPB2. Transwell assay and CCK-8 assay demonstrated that COPB2 knockdown inhibited HCT116 and SW480 cells proliferation, migration and invasion abilities. Furthermore, BMSCs-derived exosome miR-4461 downregulated COPB2 expression and inhibited HCT116 and SW480 cells migration and invasion. The findings demonstrated that miR-4461 could be a potential target for the diagnosis and treatment of colorectal cancer.

Anti-PD-1/PD-L1 therapy for colorectal cancer: Clinical implications and future considerations.

Colorectal cancer (CRC) is the third most prevalent cancer in the world. The PD-1/PD-L1 pathway plays a crucial role in modulating immune response to cancer, and PD-L1 expression has been observed in tumor and immune cells within the tumor microenvironment of CRC. Thus, immunotherapy drugs, specifically checkpoint inhibitors, have been developed to target the PD-1/PD-L1 signaling pathway, thereby inhibiting the interaction between PD-1 and PD-L1 and restoring T-cell function in cancer cells. However, the emergence of resistance mechanisms can reduce the efficacy of these treatments. To counter this, monoclonal antibodies (mAbs) have been used to improve the efficacy of CRC treatments. mAbs such as nivolumab and pembrolizumab are currently approved for CRC treatment. These antibodies impede immune checkpoint receptors, including PD-1/PD-L1, and their combination therapy shows promise in the treatment of advanced CRC. This review presents a concise overview of the use of the PD-1/PD-L1 blockade as a therapeutic strategy for CRC using monoclonal antibodies and combination therapies. Additionally, this article outlines the function of PD-1/PD-L1 as an immune response suppressor in the CRC microenvironment as well as the potential advantages of administering inflammatory agents for CRC treatment. Finally, this review analyzes the outcomes of clinical trials to examine the challenges of anti-PD-1/PD-L1 therapeutic resistance.

Management of sternal osteomyelitis and mediastinal infection following median sternotomy.

BACKGROUND: Median sternotomy is considered the most usually performed procedure in cardiac operations. This study aimed to assess clinical effectiveness of bilateral pectoralis major muscle flaps (BPMMF) for management of sternal osteomyelitis and mediastinal infection following median sternotomy. METHODS: Clinical data were collected and retrospectively analyzed from twelve patients who underwent the BPMMF transposition for management of sternal osteomyelitis and mediastinal infection following median sternotomy from January 2006 to June 2009. Procedure consisted of rigorous debridement of necrotic tissues, dead space obliteration using the BPMMF, and placement of drainage tubes connected to a negative pressures generator for adequate drainage. RESULTS: No patients died of drainage, and all 12 patients had viable BPMMF when discharged from hospital. At 1 week post discharge, 2 patients presented with sternal infection but recovered following local debridement and medication. No patients showed infection recurrence during the follow-up period over 10 months. CONCLUSIONS: Sternal osteomyelitis and mediastinal infection following median sternotomy may be effectively managed through rigorous debridement of infected soft tissues, resection of the damaged sternal segment, transposition of the BPMMF to fill the damaged sternum resulting from debridement, and adequate postoperative drainage.