lncRNA TUG1 Facilitates Colorectal Cancer Stem Cell Characteristics and Chemoresistance by Enhancing GATA6 Protein Stability

Unraveling molecular similarities between colorectal polyps and colorectal cancer: a systems biology approach

BACKGROUND/AIMS

Colorectal cancer (CRC) and colorectal polyps are intimately linked, with polyps acting as precursors to CRC. Understanding the molecular mechanisms governing their development is crucial for advancing diagnosis and treatment. Employing a systems biology approach, we investigated the molecular similarities between polyp and CRC.

METHODS

We analyzed gene expression profiles, protein-protein interactions, transcription factors, and gene ontology to identify common differentially expressed genes (DEGs) and unravel shared molecular pathways.

RESULTS

Our analysis revealed 520 commonly dysregulated genes in polyps and CRC, serving as potential biomarkers and pivotal contributors to disease progression. Gene ontology analysis elucidated distinct biological processes associated with upregulated and downregulated DEGs in both conditions, highlighting common pathways, including signal transduction, cell adhesion, and positive regulation of cell proliferation. Moreover, protein-protein interaction networks shed light on subnetworks involved in rRNA processing, positive regulation of cell proliferation, mRNA splicing, and cell division. Transcription factor analysis identified major regulators and differentially expressed transcription factors in polyp and CRC. Notably, we identified common differentially expressed transcription factors, including ZNF217, NR3C1, KLF5, GATA6, and STAT3, with STAT3 and NR3C1 exhibiting increased expression.

CONCLUSIONS

This comprehensive analysis enriches our understanding of the molecular mechanisms underlying polyp formation and CRC development, providing potential targets for further investigation and therapeutic intervention. Our findings contribute substantively to crafting personalized strategies for refining the diagnosis and treatment of polyps and CRC.

Deciphering the functional landscape and therapeutic implications of noncoding RNAs in the TGF-β signaling pathway in colorectal cancer: A comprehensive review

Colorectal cancer (CRC) remains a major global health concern, necessitating an in-depth exploration of the intricate molecular mechanisms underlying its progression and potential therapeutic interventions. Transforming Growth Factor-β (TGF-β) signaling, a pivotal pathway implicated in CRC plays a dual role as a tumor suppressor in the early stages and a promoter of tumor progression in later stages. Recent research has shed light on the critical involvement of noncoding RNAs (ncRNAs) in modulating the TGF-β signaling pathway, introducing a new layer of complexity to our understanding of CRC pathogenesis. This comprehensive review synthesizes the current state of knowledge regarding the function and therapeutic potential of various classes of ncRNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), in the context of TGF-β signaling in CRC. The intricate interplay between these ncRNAs and key components of the TGF-β pathway is dissected, revealing regulatory networks that contribute to the dynamic balance between tumor suppression and promotion. Emphasis is placed on how dysregulation of specific ncRNAs can disrupt this delicate equilibrium, fostering CRC initiation, progression, and metastasis. Moreover, the review provides a critical appraisal of the emerging therapeutic strategies targeting ncRNAs associated with TGF-β signaling in CRC. The potential of these ncRNAs as diagnostic and prognostic biomarkers is discussed, highlighting their clinical relevance. Additionally, the challenges and prospects of developing RNA-based therapeutics, such as RNA interference and CRISPR/Cas-based approaches, are explored in the context of modulating TGF-β signaling for CRC treatment. In conclusion, this review offers a comprehensive overview of the intricate interplay between ncRNAs and the TGF-β signaling pathway in CRC. By unraveling the functional significance of these regulatory elements, we gain valuable insights into the molecular landscape of CRC, paving the way for the development of novel and targeted therapeutic interventions aimed at modulating the TGF-β signaling cascade through the manipulation of ncRNAs.

Emerging roles of non-coding RNAs in colorectal cancer oxaliplatin resistance and liquid biopsy potential

Colorectal cancer (CRC) is one of the most common malignancies of the digestive tract, with the annual incidence and mortality increasing consistently. Oxaliplatin-based chemotherapy is a preferred therapeutic regimen for patients with advanced CRC. However, most patients will inevitably develop resistance to oxaliplatin. Many studies have reported that non-coding RNAs (ncRNAs), such as microRNAs, long non-coding RNAs, and circular RNAs, are extensively involved in cancer progression. Moreover, emerging evidence has revealed that ncRNAs mediate chemoresistance to oxaliplatin by transcriptional and post-transcriptional regulation, and by epigenetic modification. In this review, we summarize the mechanisms by which ncRNAs regulate the initiation and development of CRC chemoresistance to oxaliplatin. Furthermore, we investigate the clinical application of ncRNAs as promising biomarkers for liquid CRC biopsy. This review provides new insights into overcoming oxaliplatin resistance in CRC by targeting ncRNAs.

Long Non-Coding RNA and microRNA Interplay in Colorectal Cancer and Their Effect on the Tumor Microenvironment

As the current staging and grading systems are not sufficient to stratify patients for therapy and predict the outcome of the disease, there is an urgent need to understand cancer in its complexity. The mutual relationship between tumour and immune or stromal cells leads to rapid evolution and subsequent genetic and epigenetic changes. Immunoscore has been introduced as a diagnostic tool for colorectal cancer (CRC) only recently, emphasising the role of the specific tumor microenvironment in patient's prognosis and overall outcome. Despite the fact that non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), cannot be translated into proteins, they significantly affect cell's transcriptome and translatome. miRNA binding to mRNA efficiently blocks its translation and leads to mRNA destruction. On the other hand, miRNAs can be bound by lncRNAs or circular RNAs (circRNAs), which prevents them from interfering with translation. In this way, ncRNAs create a multi-step network that regulates the cell's translatome. ncRNAs are also shed by the cell as exogenous RNAs and they are also found in exosomes, suggesting their role in intercellular communication. Hence, these mechanisms affect the tumor microenvironment as much as protein signal molecules. In this review, we provide an insight into the current knowledge of the microenvironment, lncRNAs', and miRNAs' interplay. Understanding mechanisms that underlie the evolution of a tissue as complex as a tumour is crucial for the future success in therapy.

The pathogenic roles of lncRNA-Taurine upregulated 1 (TUG1) in colorectal cancer

Colorectal cancer (CRC) is a gastrointestinal tumor that develops from the colon, rectum, or appendix. The prognosis of CRC patients especially those with metastatic lesions remains unsatisfactory. Although various conventional methods have been used for the treatment of patients with CRC, the early detection and identification of molecular mechanisms associated with CRC is necessary. The scientific literature reports that altered expression of long non-coding RNAs (lncRNAs) contributed to the pathogenesis of CRC cells. LncRNA TUG1 was reported to target various miRNAs and signaling pathways to mediate CRC cell proliferation, migration, and metastasis. Therefore, TUG1 might be a potent predictive/prognostic biomarker for diagnosis of CRC.

Downregulation of miR-221-3p by LncRNA TUG1 Promoting the Healing of Closed Tibial Fractures in Mice

Objective

To probe into the effect of LncRNA TUG1 on the healing of closed tibial fracture in mice.

Methods

The closed tibial fracture model of mice was established, selecting the mouse osteoblast line MC3T3-E1, with the cells separated into four groups. The expression levels of TUG1 and miR-221-3p were determined by RT-qPCR analysis, with the targeting relationship between TUG1 and miR-221-3p authenticated by dual luciferase reporter (DLR) assay, detection of cell migration (CM) ability based on Transwell cell migration (TCM) assay, and cell proliferation (CP) acquired by cell counting kit-8 (CCK-8).

Results

Prediction results of the target gene by bioinformatics software showed that miR-221-3p had binding sites with the 3'-UTR of TUG1, and DLR assay authenticated the targeting relationship between LncRNA TUG1 and miR-221-3p. Downregulation of TUG1 inhibited osteoblast CP and CM and promoted osteoblast cell apoptosis (CA). Cell cycle analysis indicated that miR-221-3p provoked cell cycle arrest in G1 stage of MC3T3-E1 cells. The siLncRNA-NC group had higher anticyclin D1 and D3 levels than the siLncRNA TUG1 group, with a lower CA rate in the former, implying that miR-221-3p overexpression inhibited osteoblast CP and CM and LncRNA TUG1 inhibited CA. Downregulation of miR-221-3p partly reversed the retardation out of downregulating TUG1 on osteoblast CP and CM. Bcl-2 level was higher in the LncRNA TUG1 group compared to the siLncRNA TUG1 and miR-221-3p overexpression groups, with remarkably lower SDF-1 level in the miR-221-3p overexpression group than those in the control, miRNA-NC, and LncRNA TUG1 groups.

Conclusion

The downregulation of miR-221-3p by LncRNA TUG1 can promote the healing of closed tibial fractures in mice.

Regulation of the Cancer Stem Phenotype by Long Non-Coding RNAs

Cancer stem cells are a cell population within malignant tumors that are characterized by the ability to self-renew, the presence of specific molecules that define their identity, the ability to form malignant tumors in vivo, resistance to drugs, and the ability to invade and migrate to other regions of the body. These characteristics are regulated by various molecules, such as lncRNAs, which are transcripts that generally do not code for proteins but regulate multiple biological processes through various mechanisms of action. LncRNAs, such as HOTAIR, H19, LncTCF7, LUCAT1, MALAT1, LINC00511, and FMR1-AS1, have been described as key regulators of stemness in cancer, allowing cancer cells to acquire this phenotype. It has been proposed that cancer stem cells are clinically responsible for the high recurrence rates after treatment and the high frequency of metastasis in malignant tumors, so understanding the mechanisms that regulate the stem phenotype could have an impact on the improvement of cancer treatments.

The functions of long noncoding RNAs on regulation of F-box proteins in tumorigenesis and progression

Accumulated evidence has revealed that F-box protein, a subunit of SCF E3 ubiquitin ligase complexes, participates in carcinogenesis and tumor progression via targeting its substrates for ubiquitination and degradation. F-box proteins could be regulated by cellular signaling pathways and noncoding RNAs in tumorigenesis. Long noncoding RNA (lncRNA), one type of noncoding RNAs, has been identified to modulate the expression of F-box proteins and contribute to oncogenesis. In this review, we summarize the role and mechanisms of multiple lncRNAs in regulating F-box proteins in tumorigenesis, including lncRNAs SLC7A11-AS1, MT1JP, TUG1, FER1L4, TTN-AS1, CASC2, MALAT1, TINCR, PCGEM1, linc01436, linc00494, GATA6-AS1, and ODIR1. Moreover, we discuss that targeting these lncRNAs could be helpful for treating cancer via modulating F-box protein expression. We hope our review can stimulate the research on exploration of molecular insight into how F-box proteins are governed in carcinogenesis. Therefore, modulation of lncRNAs is a potential therapeutic strategy for cancer therapy via regulation of F-box proteins.

LncRNA <i>SNHG16</i> promotes colorectal cancer proliferation by regulating ABCB1 expression through sponging miR-214-3p

Mounting evidence indicates that long non-coding RNAs (lncRNAs) have critical roles in colorectal cancer (CRC) progression, providing many potential diagnostic biomarkers, prognostic biomarkers, and treatment targets. Here, we sought to investigate the role and underlying regulatory mechanism of lncRNA small nucleolar RNA host gene 16 (SNHG16) in CRC. The expressions of SNHG16 in CRC were identified by RNA-sequencing and quantitative reverse transcription PCR. The functions of SNHG16 were explored by a series of in vitro and in vivo assays (colony formation assay, flow cytometry assay, and xenograft model). Bioinformatics analysis, RNA fluorescencein situ hybridization and luciferase reporter assay were used to investigate the regulatory mechanism of effects of SNHG16. SNHG16 was found to be significantly elevated in human CRC tissues and cell lines. Functional studies suggested that SNHG16 promoted CRC cell growth both in vitro and in vivo. Mechanistically, we identified that SNHG16 is expressed predominantly in the cytoplasm. SNHG16 could interact with miR-214-3p and up-regulated its target ABCB1. This study indicated that SNHG16 plays an oncogenic role in CRC, suggesting it could be a novel biomarker and therapeutic target in CRC.