LINC00586 Represses ASXL1 Expression Thus Inducing Epithelial-To-Mesenchymal Transition of Colorectal Cancer Cells Through LSD1-Mediated H3K4me2 Demethylation

Long noncoding RNA LINC01550 inhibits colorectal cancer malignancy by suppressing the Wnt/β-catenin signaling pathway

Colorectal cancer (CRC) is a common gastrointestinal malignancy. Long noncoding RNAs (lncRNAs) are associated with the progression of various cancers, including CRC. Herein, we explored the function of lncRNA LINC01550 in CRC. LINC01550 expression in CRC was analyzed using The Cancer Genome Atlas (TCGA). The diagnostic value of LINC01550 was evaluated using ROC curves. The relationship between clinicopathological variables and LINC01550 expression was explored, and its prognostic value was assessed using Kaplan-Meier and Cox regression analyses. The relationship between LINC01550 expression and immune cell infiltration was analyzed using CIBERSORT. Tumor-associated mutations and drug sensitivity were compared between high and low LINC01550 expression groups. The effects of LINC01550 overexpression on CRC cells were investigated using CCK-8, flow cytometry, wound healing, Transwell, qRT-PCR, and western blot assays. LINC01550 was downregulated in CRC tissues, and the low expression of LINC01550 was correlated with advanced stage and metastasis. CRC patients with low LINC01550 expression had poorer overall survival. LINC01550 expression was an independent risk factor for CRC prognosis. APC and TP53 mutations were more frequent in the low LINC01550 expression group, while the high LINC01550 expression group was significantly more sensitive to 5-fluorouracil, irinotecan, trametinib, gemcitabine, rapamycin, and XAV939. LINC01550 overexpression suppressed the proliferation, migration, invasion, and epithelial-mesenchymal transition of HCT-116 and HT-29 cells and promoted apoptosis. LINC01550 exerted these effects by inhibiting Wnt/β-catenin signaling. Our results suggest LINC01550 as a diagnostic and prognostic predictor in CRC that acts as a tumor suppressor and a potential therapeutic target.

The functions and mechanisms of long non-coding RNA in colorectal cancer

CRC poses a significant challenge in the global health domain, with a high number of deaths attributed to this disease annually. If CRC is detected only in its advanced stages, the difficulty of treatment increases significantly. Therefore, biomarkers for the early detection of CRC play a crucial role in improving patient outcomes and increasing survival rates. The development of a reliable biomarker for early detection of CRC is particularly important for timely diagnosis and treatment. However, current methods for CRC detection, such as endoscopic examination, blood, and stool tests, have certain limitations and often only detect cases in the late stages. To overcome these constraints, researchers have turned their attention to molecular biomarkers, which are considered a promising approach to improving CRC detection. Non-invasive methods using biomarkers such as mRNA, circulating cell-free DNA, microRNA, LncRNA, and proteins can provide more reliable diagnostic information. These biomarkers can be found in blood, tissue, stool, and volatile organic compounds. Identifying molecular biomarkers with high sensitivity and specificity for the early and safe, economic, and easily measurable detection of CRC remains a significant challenge for researchers.

Emerging role of RNA modification and long noncoding RNA interaction in cancer

RNA modification, especially N6-methyladenosine, 5-methylcytosine, and N7-methylguanosine methylation, participates in the occurrence and progression of cancer through multiple pathways. The function and expression of these epigenetic regulators have gradually become a hot topic in cancer research. Mutation and regulation of noncoding RNA, especially lncRNA, play a major role in cancer. Generally, lncRNAs exert tumor-suppressive or oncogenic functions and its dysregulation can promote tumor occurrence and metastasis. In this review, we summarize N6-methyladenosine, 5-methylcytosine, and N7-methylguanosine modifications in lncRNAs. Furthermore, we discuss the relationship between epigenetic RNA modification and lncRNA interaction and cancer progression in various cancers. Therefore, this review gives a comprehensive understanding of the mechanisms by which RNA modification affects the progression of various cancers by regulating lncRNAs, which may shed new light on cancer research and provide new insights into cancer therapy.

Additional Sex Combs-like Family Associated with Epigenetic Regulation

The additional sex combs-like (ASXL) family, a mammalian homolog of the additional sex combs (Asx) of Drosophila, has been implicated in transcriptional regulation via chromatin modifications. Abnormal expression of ASXL family genes leads to myelodysplastic syndromes and various types of leukemia. De novo mutation of these genes also causes developmental disorders. Genes in this family and their neighbor genes are evolutionary conserved in humans and mice. This review provides a comprehensive summary of epigenetic regulations associated with ASXL family genes. Their expression is commonly regulated by DNA methylation at CpG islands preceding transcription starting sites. Their proteins primarily engage in histone tail modifications through interactions with chromatin regulators (PRC2, TrxG, PR-DUB, SRC1, HP1α, and BET proteins) and with transcription factors, including nuclear hormone receptors (RAR, PPAR, ER, and LXR). Histone modifications associated with these factors include histone H3K9 acetylation and methylation, H3K4 methylation, H3K27 methylation, and H2AK119 deubiquitination. Recently, non-coding RNAs have been identified following mutations in the ASXL1 or ASXL3 gene, along with circular ASXLs and microRNAs that regulate ASXL1 expression. The diverse epigenetic regulations linked to ASXL family genes collectively contribute to tumor suppression and developmental processes. Our understanding of ASXL-regulated epigenetics may provide insights into the development of therapeutic epigenetic drugs.