Long non-coding RNA MIAT promotes the proliferation and invasion of laryngeal squamous cell carcinoma cells by sponging microRNA-613

Epithelial‑derived head and neck squamous tumourigenesis (Review)

Head and neck squamous cell carcinomas (HNSCCs), a heterogeneous group of cancers that arise from the mucosal epithelia cells in the head and neck areas, present great challenges in diagnosis, treatment and prognosis due to their complex aetiology and various clinical manifestations. Several factors, including smoking, alcohol consumption, oncogenic genes, growth factors, Epstein‑Barr virus and human papillomavirus infections can contribute to HNSCC development. The unpredictable tumour microenvironment adds to the complexity of managing HNSCC. Despite significant advances in therapies, the prediction of outcome after treatment for patients with HNSCC remains poor, and the 5‑year overall survival rate is low due to late diagnosis. Early detection greatly increases the chances of successful treatment. The present review aimed to bring together the latest findings related to the molecular mechanisms of HNSCC carcinogenesis and progression. Comprehensive genomic, transcriptomic, metabolomic, microbiome and proteomic analyses allow researchers to identify important biological markers such as genetic alterations, gene expression signatures and protein markers that drive HNSCC tumours. These biomarkers associated with the stages of initiation, progression and metastasis of cancer are useful in the management of patients with cancer in order to improve their life expectancy and quality of life.

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.

lncRNA MIAT promotes luminal B breast cancer cell proliferation, migration, and invasion in vitro

Long noncoding RNAs (lncRNAs) play a role in the emergence and progression of several human tumors, including luminal B breast cancer (BC). The biological functions and potential mechanisms of lncRNA myocardial infarction-associated transcripts (MIAT) in luminal B BC, on the contrary, are unknown. In this work, we used UALCAN database analysis to find high expression of lncRNA MIAT in luminal BC tissues and also confirmed high levels of lncRNA MIAT expression in luminal B BC tissues and cells. In vitro knockdown of MIAT inhibited the proliferation, migration, and invasion of BT474 cells. In addition, we found that miR-150-5p levels were significantly reduced in luminal B BC specimens and cells, and miR-150-5p levels were significantly increased when MIAT was knocked down. And TIMER database analysis showed that MIAT was positively associated with PDL1. Through bioinformatic tools and in vitro experiments, lncRNA MIAT could function as a competitive endogenous RNA (CeRNA) to further regulate programmed cell death ligand 1 (PDL1) expression by directly sponging miR-150-5p. In conclusion, our data suggest that MIAT, an oncogene, may sponge miR-150-5p to regulate PDL1 expression and affect proliferation, migration, and invasion in luminal B BC in vitro.

HDAC5-mediated PRAME regulates the proliferation, migration, invasion, and EMT of laryngeal squamous cell carcinoma via the PI3K/AKT/mTOR signaling pathway

Laryngeal squamous cell carcinoma (LSCC) is an aggressive and lethal malignant neoplasm with extremely poor prognoses. Accumulating evidence has indicated that preferentially expressed antigen in melanoma (PRAME) is correlated with several kinds of cancers. However, there is little direct evidence to substantiate the biological function of PRAME in LSCC. The purpose of the current study is to explore the oncogenic role of PRAME in LSCC. PRAME expression was analyzed in 57 pairs of LSCC tumor tissue samples through quantitative real-time PCR, and the correlation between PRAME and clinicopathological features was analyzed. The result indicated that PRAME was overexpressed in the LSCC patients and correlated with the TNM staging and lymphatic metastasis. The biological functions and molecular mechanism of PRAME in LSCC progression were investigated through in vitro and in vivo assays. Functional studies confirmed that PRAME facilitated the proliferation, invasion, migration, and epithelial-mesenchymal transition of LSCC cells, and PRAME also promoted tumor growth in vivo. HDAC5 was identified as an upstream regulator that can affect the expression of PRAME. Moreover, PRAME played the role at least partially by activating PI3K/AKT/mTOR pathways. The above findings elucidate that PRAME may be a valuable oncogene target, contributing to the diagnosis and therapy of LSCC.

MIAT Is an Upstream Regulator of NMYC and the Disruption of the MIAT/NMYC Axis Induces Cell Death in NMYC Amplified Neuroblastoma Cell Lines

Neuroblastoma (NBL) is the most common extracranial childhood malignant tumor and represents a major cause of cancer-related deaths in infants. NMYC amplification or overexpression is associated with the malignant behavior of NBL tumors. In the present study, we revealed an association between long non-coding RNA (lncRNA) myocardial infarction associated transcript (MIAT) and NMYC amplification in NBL cell lines and MIAT expression in NBL tissue samples. MIAT silencing induces cell death only in cells with NMYC amplification, but in NBL cells without NMYC amplification it decreases only the proliferation. MIAT downregulation markedly reduces the NMYC expression in NMYC-amplified NBL cell lines and c-Myc expression in NMYC non-amplified NBL cell lines, but the ectopic overexpression or downregulation of NMYC did not affect the expression of MIAT. Moreover, MIAT downregulation results in decreased ornithine decarboxylase 1 (ODC1), a known transcriptional target of MYC oncogenes, and decreases the glycolytic metabolism and respiratory function. These results indicate that MIAT is an upstream regulator of NMYC and that MIAT/NMYC axis disruption induces cell death in NMYC-amplified NBL cell lines. These findings reveal a novel mechanism for the regulation of NMYC in NBL, suggesting that MIAT might be a potential therapeutic target, especially for those with NMYC amplification.