The carboxyl terminus of Hsc70-interacting protein (CHIP) is an E3 ubiquitin ligase that plays a controversial role in different cancers, either as a tumor suppressor or a tumor promoter. To date, the exact function and underlying mechanism of CHIP in colorectal cancer (CRC) is not yet clear. Here we aimed to determine whether CHIP could affect the biological behaviors of CRC cells and its underlying mechanisms. Stably transfected CHIP overexpression and depletion DLD-1 and HT-29 cells were established using Lipofectamine 2000. Cell growth was monitored by x-Celligence system. Cell proliferation was detected using CCK-8 and Brdu proliferation assay. Cell apoptosis and cell cycle were detected by flow cytometry analysis. Cell migration and invasion abilities were monitored by x-Celligence system, wound healing assay and transwell assay. In vivo intraperitoneal metastasis assay was performed to investigate the influence of CHIP on the tumor metastasis of CRC cells in nude mice. The expression of ERK, AKT, NF-кB signaling subunits and EMT related proteins were detected by Western blotting. The influence and function of CHIP on the protein expression of CRC cells were also elucidated by liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis. CRC microarray tissue was analyzed to investigate the CHIP expression and its clinical significance. CHIP depletion inhibited cell growth, migration and invasion potential of CRC cells, accompanied by downregulation of MAPK and AKT signaling activities and upregulation of E-cadherin. CHIP overexpression dramatically enhanced the migration and invasion abilities, due to the upregulation of MAPK and AKT signaling and downregulation of E-cadherin. The proteomic analysis confirmed that E-cadherin was decreased in CHIP-overexpressing CRC cells. Furthermore, clinical tissue data revealed that CHIP expression was upregulated in CRC samples and was significantly correlated with poor survival of CRC patients. Mechanically, CHIP probably activated the MAPK and AKT signaling, which inactivated GSK-3β. The GSK-3β inactivation, in turn, upregulated Slug and led to E-cadherin downregulation and EMT initiation. Our finding suggested that CHIP functions as an oncogene in the migration and metastasis of CRC, and is a potential unfavorable independent predictive biomarker for CRC. CHIP activates the AKT pathway to promote EMT and metastasis in CRC through the CHIP-MAPK/AKT-GSK-3β-Slug-E-cadherin pathways.

Nuclear transcription factor kappa B (NF-κB) subunits exhibit crucial roles in tumorigenesis and chemo-sensitivity. Recent studies suggest that RelB, the key subunit of the alternative NF-κB pathway, plays a critical role in the progression of diverse human malignancies. However, the significance of RelB in colorectal cancer (CRC) remains unclear. Here, we systematically explored the functions of the alternative NF-κB subunit RelB in colon cancer cells and its underlying mechanism. Stably transfected RelB-shRNA DLD-1 cells were established using Lipofectamine 2000. NF-κB DNA-binding capability was quantified using an ELISA-based NF-κB activity assay. Cell growth was monitored by an x-Celligence system. Cell proliferation was analyzed by a CCK-8 and a Brdu proliferation assay. Response to 5-FU was assessed by an x-Celligence system. Cell apoptosis and cell cycle was detected using flow cytometry analyses. Cell migration and invasion abilities were detected by an x-Celligence system, Transwell inserts, and wound-healing assays. RelB expression and its clinical significance were analyzed using the CRC tissue microarray. The expression of NF-κB signaling subunits, AKT/mTOR signaling molecules, cell cycle related proteins, MMP2, MMP9, and Integrin β-1 were measured by Western blotting analyses. The RelB-silencing inhibited cell growth of DLD-1 cells. The RelB-silencing exerted the anti-proliferative by downregulation of AKT/mTOR signaling. The RelB-silencing caused G0–G1 cell cycle arrested likely due to decreasing the expression of Cyclin D1 and CDK4, concomitant with increased expression of p27Kip1. The RelB-silencing enhanced cytotoxic effect of 5-FU and induced cell accumulation in S-phase. The RelB-silencing impaired the migration and invasion potential of DLD-1 cells, which was related to downregulation of MMP2, MMP9, and Integrin β-1. Importantly, the RelB expression was correlated with depth of tumor invasion, lymph node metastasis, metastasis stage, and pTNM stage. High-RelB expression was significantly correlated with poor overall survival in CRC patients. Our studies here provided evidence that RelB plays an oncogenic role and conveys chemo-resistance to 5-FU. RelB can be considered as an independent indicator of prognosis in CRC.

Staphylococcus argenteus, a member of the Staphylococcus aureus complex, has increasingly been recognized as a human pathogen but is frequently misidentified as S. aureus in routine clinical laboratories. Reports of prosthetic joint infection (PJI) caused by this species remain rare. We describe a case of delayed-onset PJI in a 71-year-old woman following total knee arthroplasty. Repeated conventional cultures were negative after empirical vancomycin therapy. Metagenomic next-generation sequencing (mNGS) of wound exudate detected S. argenteus, which guided extended culture and subsequent isolation of low-abundance colonies. Species identification was confirmed by whole-genome sequencing (WGS), multilocus sequence typing (MLST), and reinterpretation of MALDI-TOF MS results. Antimicrobial susceptibility testing (AST) was performed and compared with WGS-based resistance prediction. Phylogenetic analysis was conducted using 452 publicly available S. argenteus genomes. This study aimed to describe the clinical diagnosis, microbiological identification, and genomic characterization of a Staphylococcus argenteus strain causing prosthetic joint infection. The isolate was identified as sequence type ST2250 and lacked the staphyloxanthin operon, consistent with the non-pigmented phenotype. WGS and phenotypic AST showed 100% concordance across 11 clinically relevant antibiotics. Phylogenomic analysis revealed that the strain clustered closely with Southeast Asian lineages. Following targeted therapy with intravenous vancomycin and surgical wound management, the patient showed rapid clinical improvement with resolution of local inflammation and complete wound healing. This is the first confirmed case of S. argenteus PJI in Suzhou, China. The case highlights the diagnostic value of mNGS in culture-negative PJI, the importance of molecular tools for correctly differentiating S. argenteus from S. aureus, and the potential of WGS to support resistance prediction for rare staphylococcal pathogens.