LncRNA LINC-PINT Inhibits Malignant Behaviors of Laryngeal Squamous Cell Carcinoma Cells via Inhibiting ZEB1

Dissecting the Single-Cell Diversity and Heterogeneity Underlying Cervical Precancerous Lesions and Cancer Tissues

The underlying cellular diversity and heterogeneity from cervix precancerous lesions to cervical squamous cell carcinoma (CSCC) is investigated. Four single-cell datasets including normal tissues, normal adjacent tissues, precancerous lesions, and cervical tumors were integrated to perform disease stage analysis. Single-cell compositional data analysis (scCODA) was utilized to reveal the compositional changes of each cell type. Differentially expressed genes (DEGs) among cell types were annotated using BioCarta. An assay for transposase-accessible chromatin sequencing (ATAC-seq) analysis was performed to correlate epigenetic alterations with gene expression profiles. Lastly, a logistic regression model was used to assess the similarity between the original and new cohort data (HRA001742). After global annotation, seven distinct cell types were categorized. Eight consensus-upregulated DEGs were identified in B cells among different disease statuses, which could be utilized to predict the overall survival of CSCC patients. Inferred copy number variation (CNV) analysis of epithelial cells guided disease progression classification. Trajectory and ATAC-seq integration analysis identified 95 key transcription factors (TF) and one immunohistochemistry (IHC) testified key-node TF (YY1) involved in epithelial cells from CSCC initiation to progression. The consistency of epithelial cell subpopulation markers was revealed with single-cell sequencing, bulk sequencing, and RT-qPCR detection. KRT8 and KRT15, markers of Epi6, showed progressively higher expression with disease progression as revealed by IHC detection. The logistic regression model testified the robustness of the resemblance of clusters among the various datasets utilized in this study. Valuable insights into CSCC cellular diversity and heterogeneity provide a foundation for future targeted therapy.

Long non-coding RNA LINC-PINT is associated with favorable prognosis in cancer patients: a systematic review and meta-analysis

Background

There is growing evidence that long non-coding RNA long iatrogenic non-protein-coding RNA p53-induced transcript (LINC-PINT) is highly expressed in cancer tissue and is associated with the prognosis of cancer patients. The present study systematically analyzed the prognostic significance of LINC-PINT expression in cancer patients. We aimed to reveal the association between LINC-PINT expression and survival in cancer patients.

Methods

We collected eligible studies through the PubMed, Embase, and Cochrane library searches until February 1, 2024. We collected the following data from the enrolled studies: first author, publication year, country, cancer type, case number, cancer stage, detection method and cut-off value of LINC-PINT expression, follow-up period, and survival outcome. The prognostic significance of LINC-PINT expression was evaluated by conducting a meta-analysis. StataSE17 (Stata, College Station, TX, USA) was used for all analyses.

Results

Eleven eligible studies with 2,876 cancer patients were collected. The pooled results revealed that LINC-PINT expression was associated with favorable overall survival (OS) and disease-free survival (DFS) in cancer patients [for OS, hazard ratio (HR) =0.72, 95% confidence interval (CI): 0.64-0.80, P<0.001; for DFS, HR =0.70, 95% CI: 0.60-0.82, P<0.001].

Conclusions

LINC-PINT expression was associated with favorable OS and DFS, and it may serve as a valuable prognostic marker in cancer patients.

LINC-PINT plays an anti-tumor role in nasopharyngeal carcinoma by binding to XRCC6 and affecting its function

BACKGROUND

LINC-PINT was downregulated in nasopharyngeal carcinoma (NPC) and correlated with treatment efficiency of NPC. However, the underlying mechanism of LINC-PINT in NPC has not yet been fully explored.

METHOD

We used CellTiter luminescent assay, clone formation assay, Hoechst staining, and SYTO-9/PI staining to examine cell viability and cell apoptosis regulated by LINC-PINT in NPC cells. Xenograft tumor model, HE staining, Ki67 staining, and TUNEL assay were conducted to assess the role of LINC-PINT in vivo. Bioinformatics and RNA immunoprecipitation assay was performed to identify the binding protein of LINC-PINT. Fluorescence in situ hybridization and immunofluorescence were utilized to measure the colocalization of XRCC6 with LINC-PINT and DNA-PKcs. Mito-Tracker red CMXRos staining was used to label mitochondria in cells specifically.

RESULT

We found LINC-PINT was downregulated in many tumors (including NPC) and associated with poor prognosis. The cell viability was significantly inhibited and cell apoptosis was remarkably promoted in LINC-PINT overexpressed cells in contrast to control cells. The growth of tumor xenografts was significantly suppressed and the tumor weight was significantly decreased in LINC-PINT overexpression group compared to the control group. Correspondingly, the positive Ki67 foci was decreased while TUNEL foci was increased in LINC-PINT overexpression group. Mechanically, we verified XRCC6 as a new binding protein of LINC-PINT through RNA binding domains prediction, RIP and colocalization of LINC-PINT and XRCC6. By binding to XRCC6, LINC-PINT interfered the formation of DNA-PK complex, regulated mitochondria accumulation status and affected the modification of apoptosis proteins, leading to more cell apoptosis.

CONCLUSION

Our study provided the first evidence that LINC-PINT promotes cell apoptosis in NPC by binding to XRCC6 and affecting its function.

Exosomal lncRNA LINC02191 Promotes Laryngeal Squamous cell Carcinoma Progression by Targeting miR-204-5p/RAB22A Axis and Regulating PI3K/Akt/mTOR Pathway

Recent research has explored the potential use of serum-derived biomarkers in cancer screening, and mounting evidence has illustrated the pivotal roles of long noncoding RNAs (lncRNAs) in regulating laryngeal squamous cell carcinoma (LSCC) progression. LINC02191 is a newly identified lncRNA and no studies have investigated its role in malignant tumors. This study aims to explore the functions and mechanisms of lncRNA LINC02191 in LSCC. LINC02191 was knocked down in LSCC cells using shRNAs for loss-of-function experiments. RT-qPCR revealed that LINC02191 was upregulated in LSCC patients' serum exosomes, tissues and cells. Western blotting and RT-qPCR were implemented for detecting molecular protein and RNA levels. Colony formation, CCK-8, wound healing and Transwell assays were employed for examining LSCC cell malignant behaviors in vitro. A tumor-bearing mouse model (n = 4/group) was established for examining LINC02191 role in vivo. The results showed that LINC02191 silencing hindered LSCC cell proliferation, invasiveness, migration as well as EMT in vitro and impeded tumorigenesis in xenograft mouse model. Luciferase reporter assay was utilized for verifying the interaction between LINC02191, miR-204-5p and RAB22A. Pearson correlation analysis was employed to evaluate their expression correlation in LSCC tissue specimens (N = 30). Mechanistically, LINC02191 upregulated RAB22A by binding to miR-204-5p, and knocking down LINC02191 inhibited PI3K/Akt/mTOR signaling transduction in LSCC cells and tumor-bearing mice. Moreover, RAB22A overexpression reversed LINC02191 depletion-triggered suppression of LSCC cell aggressiveness and inactivation of PI3K/Akt/mTOR signaling. In conclusion, LINC02191 aggravates LSCC by targeting miR-204-5p/RAB22A/PI3K/Akt/mTOR signaling pathway, which indicates that LINC02191 may serve as a promising target for LSCC treatment.

Long non-coding RNA LINC-PINT as a novel prognostic biomarker in human cancer: a meta-analysis and machine learning

Long intergenic non-protein coding RNA, P53 induced transcript (LINC-PINT) exhibits different expression patterns in the majority of tumors, yet its relationship with cancer prognosis remains a subject of debate. This study aims to comprehensively investigate the prognostic significance of LINC-PINT in diverse human cancer. A systematic search was conducted in PubMed, Embase, Cochrane Library, and Web of Science databases to identify pertinent studies exploring the correlation between LINC-PINT expression and cancer patients. Moreover, bioinformatics analysis and in vitro validation were used to validate the results of the meta-analysis and to investigate the potential oncogenic mechanism of LINC-PINT. The meta-analysis encompassed 8 studies, involving 911 patients. The pooled analysis demonstrated a significant association between upregulation of LINC-PINT expression and better survival (P = 0.002) during the cancers. Meanwhile, its downregulation was correlated with advanced tumor staging (P = 0.04) and tumor differentiation (P = 0.03). Additionally, bioinformatics analysis showed that LINC-PINT expression was observed to be linked with Tumor Mutational Burden (TMB) and Microsatellite Instability (MSI) in tumors, the results of bioinformatics were verified by qRT-PCR. And functional enrichment analysis hinted at its involvement in tumorigenesis and tumor progression. Dysregulated LICN-PINT expression is associated with the clinical prognostic and pathological features of various cancers, exhibiting substantial potential as a novel prognostic biomarker.

Downregulation of long noncoding RNA HCP5/miR-216a-5p/ZEB1 axis inhibits the malignant biological function of laryngeal squamous cell carcinoma cells

Previous studies find that long noncoding RNA human leukocyte antigen complex P5 (HCP5) is regarded as an oncogene via accelerating cancer cell growth, invasion, metastasis, vascularization, and drug resistance in renal cell carcinoma, gastric cancer, and colorectal cancer. Nevertheless, the effect and regulatory mechanism of HCP5 in laryngeal squamous cell carcinoma (LSCC) remains unknown. In this study, HCP5 expression levels were confirmed to be prominently raised in LSCC cell lines. HCP5 knockdown reduced cell proliferation and migration and invasive ability of LSCC cell lines. Furthermore, miR-216a-5p was confirmed to sponge HCP5, and its expression was prominently downregulated in LSCC cell lines and upregulated in HCP5-silenced LSCC cell lines. miR-216a-5p overexpression downregulated the cell proliferation and migration and invasive ability of LSCC cells. Additionally, the protein level of zinc finger E-box binding homeobox 1 (ZEB1), one target gene of miR-216a-5p, was highly expressed in LSCC cell lines, and its expression level was downregulated by HCP5 knockdown and miR-216a-5p overexpression. An miR-216a-5p inhibitor reversed the effect of HCP5 knockdown on the proliferation and migration and invasive ability of LSCC cells. In conclusion, knocking down HCP5 may be a strategy to suppress the malignant biological function via regulating miR-216a-5p/ZEB1. Therefore, HCP5 may become a prospective therapeutic target for LSCC.

PINTology: A short history of the lncRNA LINC-PINT in different diseases

LINC-PINT is a p53-induced long intergenic noncoding transcript that plays a crucial role in many diseases, especially cancer. This long noncoding RNA (lncRNA) gene produces in total 102 (LNCipedia) alternatively spliced variants (LINC-PINT:1 to LINC-PINT:102). The functions of known variants include RNA transcripts, host transcripts for circular RNA (circRNA) generation and as sources for the translation of short peptides. In most human tumors, LINC-PINT is down-regulated where it serves as a tumor suppressor. However, the diversity of its functions in other maladies signifies its general clinical importance. Current LINC-PINT molecular functions include RNA-protein interactions, miRNA sponging and epigenetic modulation with these mechanisms operating in different cellular contexts to exert effects on biological processes ranging from DNA damage responses, cell cycle and growth arrest, senescence, cell migration and invasion, and apoptosis. Genetic polymorphisms in LINC-PINT have also been functionally associated with cancer and other pathologies including the autoimmune diseases pemphigus foliaceus and arthritis. Hence, LINC-PINT shows great potential as a clinical biomarker, especially for the diagnosis and prognosis of cancer. In this review, we explore the current knowledge highlighting the distinctive molecular functions of LINC-PINT in specific cancers and other disease states. This article is categorized under: RNA in Disease and Development > RNA in Disease.

TWIST1 methylation by SETD6 selectively antagonizes LINC-PINT expression in glioma

Gliomas are one of the most common and lethal brain tumors among adults. One process that contributes to glioma progression and recurrence is the epithelial to mesenchymal transition (EMT). EMT is regulated by a set of defined transcription factors which tightly regulate this process, among them is the basic helix-loop-helix family member, TWIST1. Here we show that TWIST1 is methylated on lysine-33 at chromatin by SETD6, a methyltransferase with expression levels correlating with poor survival in glioma patients. RNA-seq analysis in U251 glioma cells suggested that both SETD6 and TWIST1 regulate cell adhesion and migration processes. We further show that TWIST1 methylation attenuates the expression of the long-non-coding RNA, LINC-PINT, thereby promoting EMT in glioma. Mechanistically, TWIST1 methylation represses the transcription of LINC-PINT by increasing the occupancy of EZH2 and the catalysis of the repressive H3K27me3 mark at the LINC-PINT locus. Under un-methylated conditions, TWIST1 dissociates from the LINC-PINT locus, allowing the expression of LINC-PINT which leads to increased cell adhesion and decreased cell migration. Together, our findings unravel a new mechanistic dimension for selective expression of LINC-PINT mediated by TWIST1 methylation.