LncRNA LINC01315 silencing modulates cancer stem cell properties and epithelial-to-mesenchymal transition in colorectal cancer via miR-484/DLK1 axis

Association between lncRNAs with stem cells in cancer; a particular focus on lncRNA-CSCs axis in cancer immunopathogenesis

A unique population of cells known as cancer stem cells (CSCs) is essential to developing and spreading cancer. Cancer initiation, maintenance, and progression are all believed to be significantly impacted by the distinct characteristics these cells exhibit regarding self-renewal, proliferation, and differentiation. Transcriptional, post-transcriptional, and translational processes are the only steps of gene expression that lncRNAs can affect. As a result, these proteins participate in numerous biological processes, including the repair of DNA damage, inflammatory reactions, metabolic control, the survival of cells, intercellular communication, and the development and specialization of cells. Studies have indicated that lncRNAs are important for controlling the increase in the subset of CSCs contributing to cancer development. The knowledge that is currently available about lncRNAs and their critical role in maintaining the biological properties of CSCs is highlighted in this study.

Comprehensive characterization of stemness-related lncRNAs in triple-negative breast cancer identified a novel prognostic signature related to treatment outcomes, immune landscape analysis and therapeutic guidance: a silico analysis with in vivo experiments

BACKGROUND

Cancer stem cells (CSCs) and long non-coding RNAs (lncRNAs) are known to play a crucial role in the growth, migration, recurrence, and drug resistance of tumor cells, particularly in triple-negative breast cancer (TNBC). This study aims to investigate stemness-related lncRNAs (SRlncRNAs) as potential prognostic indicators for TNBC patients.

METHODS

Utilizing RNA sequencing data and corresponding clinical information from the TCGA database, and employing Weighted Gene Co-expression Network Analysis (WGCNA) on TNBC mRNAsi sourced from an online database, stemness-related genes (SRGs) and SRlncRNAs were identified. A prognostic model was developed using univariate Cox and LASSO-Cox analysis based on SRlncRNAs. The performance of the model was evaluated using Kaplan-Meier analysis, ROC curves, and ROC-AUC. Additionally, the study delved into the underlying signaling pathways and immune status associated with the divergent prognoses of TNBC patients.

RESULTS

The research identified a signature of six SRlncRNAs (AC245100.6, LINC02511, AC092431.1, FRGCA, EMSLR, and MIR193BHG) for TNBC. Risk scores derived from this signature were found to correlate with the abundance of plasma cells. Furthermore, the nominated chemotherapy drugs for TNBC exhibited considerable variability between different risk score groups. RT-qPCR validation confirmed abnormal expression patterns of these SRlncRNAs in TNBC stem cells, affirming the potential of the SRlncRNAs signature as a prognostic biomarker.

CONCLUSION

The identified signature not only demonstrates predictive power in terms of patient outcomes but also provides insights into the underlying biology, signaling pathways, and immune status associated with TNBC prognosis. The findings suggest the possibility of guiding personalized treatments, including immune checkpoint gene therapy and chemotherapy strategies, based on the risk scores derived from the SRlncRNA signature. Overall, this research contributes valuable knowledge towards advancing precision medicine in the context of TNBC.

Baseline Expression of Exosomal miR-92a-3p and miR-221-3p Could Predict the Response to First-Line Chemotherapy and Survival in Metastatic Colorectal Cancer

The status of predictive biomarkers in metastatic colorectal cancer is currently underdeveloped. Our study aimed to investigate the predictive value of six circulating exosomal miRNAs derived from plasma (miR-92a-3p, miR-143-3p, miR-146a-5p, miR-221-3p, miR-484, and miR-486-5p) for chemosensitivity, resistance patterns, and survival. Thirty-one metastatic colorectal cancer patients were selected before receiving first-line irinotecan- or oxaliplatin-based chemotherapy. Blood samples were harvested at baseline and 4-6 months after the initiation of chemotherapy. The levels of exosomal expression for each miRNA were analyzed by qPCR. Our results for patients receiving first-line FOLFOX showed significantly higher baseline levels of miR-92a-3p (p = 0.007 **), miR-146a-5p (p = 0.036 *), miR-221-3p (p = 0.047 *), and miR-484 (p = 0.009 **) in non-responders (NR) vs. responders (R). Of these, miR-92a-3p (AUC = 0.735), miR-221-3p (AUC = 0.774), and miR-484 (AUC = 0.725) demonstrated a predictive ability to discriminate responses from non-responses, regardless of the therapy used. Moreover, Cox regression analysis indicated that higher expression levels of miR-92a-3p (p = 0.008 **), miR-143-3p (p = 0.009 **), miR-221-3p (p = 0.016 *), and miR-486-5p (p = 0.019 *) at baseline were associated with worse overall survival, while patients expressing higher baseline miR-92a-3p (p = 0.003 **) and miR-486-5p (p = 0.003 **) had lower rates of progression-free survival. No predictive values for candidate microRNAs were found for the post-chemotherapy period. In line with these findings, we conclude that the increased baseline exosomal expression of miR-92a-3p and miR-221-3p seems to predict a lack of response to chemotherapy and lower OS. However, further prospective studies on more patients are needed before drawing practice-changing conclusions.

Long non-coding RNA TDRG1 aggravates colorectal cancer stemness by binding with miR-873-5p to upregulate PRKAR2

The effects of long non-coding RNA TDRG1 have been established in several tumors; however, its roles in colorectal cancer (CRC) progression are never been found. Here, we found that TDRG1 level was upregulated in CRC cells compared to that in normal colon epithelial cells. Additionally, TDRG1 level was remarkably upregulated in 3D non-adherent spheres derived from the parental CRC cells. Further in vitro and in vivo revealed that TDRG1 knockdown suppressed the stemness of CRC cells. What's more, combined with bioinformatics analysis, luciferase reporter and RNA pull down experiments showed that TDRG1 could bind to miR-873-5p, downregulated its level and thus increase the expression of PRKAR2. Finally, it was shown that TDRG1 functioned through the miR-873-5p/PRKAR2 axis. This study demonstrated a novel TDRG1/miR-873-5p/PRKAR2 signaling in CRC progression.

RP11-79H23.3 Inhibits the Proliferation and Metastasis of Non-small-cell Lung Cancer Through Promoting miR-29c

Evidences indicate that long non-coding RNAs (lncRNAs) are closely involved and contributed to tumorigenesis and cancer progression. As a novel lncRNA, RP11-79H23.3 was found to be an anti-oncogene in bladder cancer. However, the essential roles and functions of RP11-79H23.3 in non-small-cell lung cancer (NSCLC) remains to be elucidated. Here, loss of functional assay was applied to gain insights into the functions of RP11-79H23.3 on the proliferation and metastasis capabilities of A549 and H1299 cells. Meantime, Real-time PCR was utilized to measure RP11-79H23.3 and miR-29c expression in NSCLC tissues. Dual-luciferase reporter assay, CCK8, colony formation assay, transwell and Western blot were performed to illustrate the potential molecular basis of RP11-79H23.3 in NSCLC. RP11-79H23.3 downregulation facilitated cell proliferation, migration, and invasion of NSCLC. The result of dual-luciferase reporter assay represented a direct interaction of RP11-79H23.3 with miR-29c, which suppressed miR-29c expression that showed inversely correlation in NSCLC. Moreover, RP11-79H23.3 siRNA facilitated the progression of NSCLC partially via regulating the expression of miR-29c and the activation of Wnt/β-catenin signaling pathway. Our findings highlighted that RP11-79H23.3, served as an anti-oncogene, accelerated NSCLC progression through sequestering miR-29c, providing a promising therapeutic target for NSCLC.