Multi-Omics Characteristics of Ferroptosis Associated with Colon Adenocarcinoma Typing and Survival.

BACKGROUND: Ferroptosis, an iron-dependent form of cell death, plays a crucial role in the progression of various cancers, including colon adenocarcinoma (COAD). However, the multi-omics signatures relevant to ferroptosis regulation in COAD diagnosis remain to be elucidated. METHODS: The transcriptomic, miRNAomic, and methylomic profiles of COAD patients were acquired from the Cancer Genome Atlas (TCGA). Ferroptosis activity in these patients was determined, represented by a ferroptosis score (FS), using single-sample gene set enrichment analysis (ssGSEA) based on the expression of ferroptosis-related genes. RESULTS: Results showed that the COAD patients with high-FS displayed favorable survival outcomes and heightened drug sensitivity. They also exhibited an up-regulation of genes involved in immune-related pathways (e.g., tumor necrosis factor signaling pathway), suggesting a correlation between immunity and ferroptosis in COAD progression. Furthermore, three survival prediction models were established based on 10 CpGs, 12 long non-coding RNAs (lncRNAs), and 14 microRNAs (miRNAs), respectively. These models demonstrated high accuracy in predicting COAD survival, achieving areas under the curve (AUC) >0.7. The variables used in the three models also showed strong correlations at different omics levels and were effective at discriminating between high-FS and low-FS COAD patients (AUC >0.7). CONCLUSIONS: This study identified different DNA methylation (DNAm), lncRNA, and miRNA characteristics between COAD patients with high and low ferroptosis activity. Furthermore, ferroptosis-related multi-omics signatures were established for COAD prognosis and classification. These insights present new opportunities for improving the efficacy of COAD therapy.

CXCL8, overexpressed in colorectal cancer, enhances the resistance of colorectal cancer cells to anoikis.

Anoikis is a form of apoptosis which occurs when anchorage-dependent cells either show loss of adhesion or inappropriate adhesion. Only a few cancer cells that detach from the primary site of the tumor acquire the ability to resist anoikis and form metastasis. The mechanism underlying the resistance of colorectal cancer (CRC) cells to anoikis remains unclear. Interleukin-8 (alternatively known as CXCL8) is associated with CRC angiogenesis and progression. Here, we found that a high abundance of CXCL8 or TOPK strongly correlated with poor overall and disease-free survival of 186 patients with CRC. A combination of high CXCL8 and high TOPK expressions had the worst prognosis. We showed that CXCL8 expression was negatively correlated with anoikis in CRC cells. CXCL8 treatment enhanced the resistance of CRC cells to apoptosis, which was accompanied by the increase of TOPK, and the activation of AKT and ERK. Moreover, we demonstrated that the inhibition of either ERK or AKT by specific chemical inhibitors attenuated the CXCL8-mediated resistance to anoikis. Treatment with AKT inhibitor abolished the effects of CXCL8 on TOPK expression, suggesting that TOPK was downstream of AKT in the process of anoikis. Taken together, we demonstrated that CXCL8 is strongly implicated in the resistance of CRC cells to anoikis, and that the AKT, TOPK and ERK pathway may be a potential therapeutic target for CRC.

CCL20 and CXCL8 synergize to promote progression and poor survival outcome in patients with colorectal cancer by collaborative induction of the epithelial-mesenchymal transition.

Liver metastases represent the major cause of death in patients with colorectal cancer (CRC). Recent studies have suggested that the chemotactic responses of tumor cells are necessary for metastatic spread to the liver, and CCL20 and CXCL8 have a strong association with CRC metastasis. The aim of our study was to identify the mechanisms by which CCL20 and CXCL8 synergize to promote metastatic progression and evaluated their potential as prognostic markers for CRC patients. The abilities of CCL20 and CXCL8 to promote CRC cell progression and epithelial-mesenchymal transition(EMT)phenotype were analyzed in vitro. Possible signaling pathways were investigated with specific pathway inhibitors and small interfering RNA (siRNA). 213 Patients with CRC who underwent surgery were enrolled for analysis of CCL20, CXCL8 and E-cadherin expressions in tumor tissues. Prognostic factors were then identified. CCL20 or CXCL8 alone was not sufficient to induce complete EMT in CRC cells, but both of them could coordinately induce EMT-like phenotype that was required to maintain CRC cell proliferation, migration and invasion. PI3K/AKT-ERK1/2 pathway crosstalk was demonstrated to be responsible for this process. Coexpression of CCL20 and CXCL8 was negatively correlated with E-cadherin expression in human CRC tissues. CRC patients with coexpression of CCL20 and CXCL8 were more likely to develop liver metastases and both coexpression was an independent high-risk factor for a most poor prognosis. CCL20 and CXCL8 synergize to promote CRC metastatic progression by coordinated induction of EMT via PI3K/AKT-ERK1/2 signaling axis. Detection of both coexpressions can be used to predict clinical outcomes in CRC patients.