Colorectal cancer (CRC) ranks as the third most commonly diagnosed cancer and the second leading cause of cancer-related deaths worldwide. Studies have shown that CRC patients with KRAS mutations, especially KRASG12D, have an increased risk of metastasis. Emerging evidence indicates that long non-coding RNAs (lncRNAs) are crucial in the carcinogenesis and progression of various cancers, regulating multiple biological processes but the link between KRASG12D mutations and lncRNAs in CRC remains unclear. Therefore, this study was designed to identify a novel lncRNA involved in KRASG12D-mutated CRC and to elucidate its molecular mechanisms. The analysis of differentially expressed lncRNAs in the GSE201412 dataset revealed that LINC02159 was significantly upregulated following treatment with the KRASG12D inhibitor MTRX1133 Data from the GTEx database indicated that LINC02159 is highly expressed in CRC tumour tissues and is associated with better patient outcomes. In vitro and in vivo experiments suggest that LINC02159 acts as a tumour suppressor in CRC progression. Specifically, LINC02159 knockdown negated the inhibitory effects of MRTX1133 on tumourigenesis and its promotive effect on ferroptosis in KRASG12D-mutated CRC cells. LINC02159 expression is regulated by METTL14, with METTL14 knockdown decreasing m6A methylation of LINC02159, leading to its increased expression in CRC cells. Additionally, LINC02159 stabilised FOXC2 expression through de-ubiquitination. Rescue experiments further clarified that the METTL14/LINC02159/FOXC2 signalling axis is crucial for the inhibitory effects of MRTX1133 in KRASG12D-mutated CRC. Our study provides novel insights into the therapeutic potential of MRTX1133 in treating KRASG12D-mutated CRC by identifying a METTL14/LINC02159/FOXC2 signalling axis that mediates drug response. Our findings highlight the importance of understanding the molecular mechanisms of lncRNAs in cancer to develop effective targeted therapies.
Colon cancer is a common malignant tumor in the digestive tract, with relatively high rates of morbidity and mortality. It is the third most common type of tumor in the world. The effective treatment of advanced colon cancer is limited, so it is particularly important to study the new pathogenesis of colon cancer. Ferroptosis is a nonapoptotic regulated cell death mode driven by iron-dependent lipid peroxidation, a process which has been discovered in recent years. Autophagy involves lysosomal degradation pathways that promote or prevent cell death. High levels of autophagy are associated with ferroptosis, but a clear association has not yet been made between ferroptosis and autophagy in colon cancer. Through the analysis of transcriptome expression profiling data in colon cancer, we obtained the common upregulated genes and downregulated genes by recording the intersection of the differentially expressed genes in each dataset. Solute Carrier Family 2 Member 1 (SLC2A1) was identified by combining autophagy genes obtained from GeneCards and ferroptosis genes obtained from FerrDb. In order to explore the clinical significance and prognostic value of SLC2A1, we utilized massive databases to conduct an in-depth exploration of the methylation of SLC2A1, and we also investigated the differences in immune infiltration between tumor and normal tissues. We found that there are abundant methylation sites in SLC2A1 and that the methylation of SLC2A1 is correlated with the immunosuppression of tumor tissue. We discovered that during the induction of environmental factors, the transcription and methylation levels of SLC2A1 were greatly increased, autophagy and ferroptosis were inhibited, and the immune system was defective, resulting in a poor prognosis for patients. These results suggest that the autophagy and ferroptosis-related gene SLC2A1 is involved in the tumor immune regulation of colon cancer, and SLC2A1 may become a new therapeutic target for colon cancer.
26 February 2022 in Canadian Journal of Gastroenterology and Hepatology
Gastric cancer is one of the cancers with the highest incidence in the world. Gamma-glutamyltransferase 5 (GGT5) is expressed in different cancers and its role in cancers remains unclear. In this study, we aimed to evaluate the value of GGT5 in stomach adenocarcinoma (STAD). In TCGA, patients with high GGT5 expression had poor overall survival ( ). Based on GSE62254, high expression of GGT5 was associated with poor OS ( ) and PFS ( ). The same result was observed in GSE14210. We further discovered that GGT5 expression was associated with stage, grade, and T stage. Further prognostic analysis of GGT5 showed that GGT5 was associated with prognosis in both univariate analysis ( ) and multivariate analysis ( ). We used gene set enrichment analysis (GSEA) to explore the possible mechanism of GGT5. GSEA suggests that overexpression of GGT5 may be involved in leukocyte transendothelial migration, JAK-STAT signaling pathway, MAPK signaling pathway, and melanoma. The high-expression GGT5 group had higher concentrations of M2 macrophages, T cell regulators, and monocytes, but the contents of plasma cells and M1 macrophages were higher in the low-expression GGT5 group. The results showed that the ESTIMATEScore, ImmuneScore, and StromalScore of the high-expression GGT5 group were higher than those of the low-expression GGT5 group. PD1 and CTLA4 expression levels were higher in the high-expression GGT5 group. The high-expression GGT5 group may be more effective for immunotherapy. These results suggested that GGT5 could be a potential prognostic molecular predictor in STAD.
27 September 2024 in Journal of Cellular and Molecular Medicine
Colorectal cancer (CRC) represents a significant malignancy within the digestive system, characterized by high incidence and mortality rates. In recent years, molecular targeted therapy has been introduced as a supplementary strategy in CRC management, complementing traditional modalities such as surgery, radiation and chemotherapy. The identification of novel therapeutic targets for CRC remains critically important. Ferroptosis, a unique form of programmed cell death distinct from apoptosis and necrosis, is characterized by cellular damage resulting from iron‐induced lipid peroxidation, leading to cell death. This study utilizes a combination of bioinformatics analysis and clinical specimen validation to demonstrate that the long non‐coding RNA (lncRNA) ALMS1‐IT1 is significantly upregulated in CRC tissues and strongly associated with ferroptosis. Through a series of experimental investigations, we have determined that ALMS1‐IT1 negatively regulates ferroptosis in CRC cells, thereby promoting cancer growth and metastasis, acting as an oncogenic factor. Furthermore, we explored the molecular interactions of ALMS1‐IT1, revealing its role in activating STAT3 protein phosphorylation. This activation enhances the immune evasion capabilities of CRC cells. Rescue experiments indicated that STAT3 activation is essential for ALMS1‐IT1's suppression of ferroptosis, immune evasion and oncogenic behaviour in CRC. Our findings underscore the critical biological role of ALMS1‐IT1 in the progression of CRC and suggest its potential as a target for drug development.