Circ_0120175 promotes laryngeal squamous cell carcinoma development through up-regulating SLC7A11 by sponging miR-330-3p

High hsa_circ_0081621 expression indicates a poor prognosis of laryngeal squamous cell carcinoma: A bioinformatics analysis and retrospective clinical study

Laryngeal squamous cell carcinoma (LSCC) is the second most common malignant tumour of the head and neck with a low 5-year survival rate. There is need to identify novel biomarkers for diagnosis and treatment of LSCC. The present study identified differentially expressed circular RNAs (circRNAs/circs) in LSCC and larynx adjacent non-carcinoma epithelial specimens by analysing the circRNA microarray dataset GSE117001. hsa_circ_0081621 had highest expression among three circRNAs (hsa_circ_0015211, hsa_circ_0023326 and hsa_circ_0081621) in LSCC specimens by reverse transcription-quantitative PCR. The expression levels of hsa_circ_0081621 in 67 LSCC specimens were detected by fluorescence in situ hybridization (FISH). Expression levels of hsa_circ_0081621 were analysed in relation to clinicopathological parameters and prognosis of patients with LSCC. According to FISH results, 59.7% of LSCC specimens exhibited high hsa_circ_0081621 expression. In LSCC specimens, hsa_circ_0081621 high expression was associated with lymph node metastasis and high clinical stage. High expression levels of hsa_circ_0081621 were associated with a poor 5-year overall survival rate in patients with LSCC. In addition, high hsa_circ_0081621 expression was an independent prognostic factor for patients with LSCC. hsa_circ_0081621 may participate in malignant progression of LSCC, and its high expression could be used for prognostic assessment of patients with LSCC.

Circ_103128 is associated with the tumorigenesis of medulloblastoma

BACKGROUND & AIMS

Medulloblastoma (MB) is a primary malignant tumor of the brain. They are categorized as WHO grade IV neoplasms, and mostly occur in children. The traditional therapy for MB is surgery, followed by radiation and chemotherapy, but the clinical outcome is still poor and has a high possibility of recurrence. The mechanism underlying the development of MB should be further investigated to develop novel therapeutic strategies.

METHODS

Research has demonstrated that circRNAs contribute to tumorigenesis, but the functional mechanism of circRNAs in MB has not been fully explored and remains vague. The differentially expressed circRNAs between MB and normal cerebellar tissues were analyzed based on the microarray expression profiles to characterize the potential mechanism of circRNAs in MB.

RESULTS

The results revealed that circRNA_103128 was highly expressed in MB, and cellular and animal experiments were performed to verify its tumorigenic effect in MB. Furthermore, a bioinformatics analysis and literature review previous literature were performed, confirming miR-129-5p as a target gene downstream of circRNA_103128. In addition, SOX4 was predicted to be a downstream target protein of miR-129-5p. Subsequently, miR-129-5p expression was inhibited, which revealed the regulatory mechanism of circRNA_103128. The latter promotes MB cell growth, migration, and invasion by the sponge effect of miR-129-5p, thereby affecting the expression of SOX4.

CONCLUSIONS

This study is the first to systematically demonstrate that circRNA_103128 may play an important regulatory role in MB through a sponge effect with miR-129 -5p, which affects SOX4 expression and regulates tumorigenesis and tumor cell development in MB.

Circular RNA circSLC7A11 contributes to progression and stemness of laryngeal squamous cell carcinoma via sponging miR-877-5p from LASP1

Background

Laryngeal squamous cell carcinoma (LSCC) belongs to tumors of head and neck. Circular RNA circSLC7A11 functions as oncogenes in various tumors. However, the role of circSLC7A11 in LSCC remains largely unknown. Here, we aimed to clarify the circSLC7A11 function in LSCC.

Methods

Relevance between circSLC7A11 expressions and LSCC clinicopathological was checked using chi-square. Relevance between circSLC7A11 expressions and LSCC patients' survival time was validated using Kaplan-Meier analysis. CircSLC7A11 expressions in LSCC tissues and cells were determined using quantitative real-time PCR. CircSLC7A11 functions in LSCC were examined by Cell Counting Kit-8, EdU analysis, Western blot, flow cytometry, sphere formation assay, and Transwell analysis. Meanwhile, circSLC7A11 mechanism in LSCC was determined using dual-luciferase reporter analysis, RNA pull-down, RNA Immunoprecipitation.

Results

CircSLC7A11 was highly expressed in LSCC, and high circSLC7A11 expressions were interrelated to the TNM stage. Also, LSCC patients with high circSLC7A11 owned shorter overall survival. Functional studies revealed that circSLC7A11 knockdown reduced LSCC cell proliferation, migration, invasion, stemness characteristics, and enhanced cell apoptosis. Mechanistic study data corroborated that circSLC7A11 targeted miR-877-5p, miR-877-5p targeted LASP1. LASP1 was negatively interrelated to miR-877-5p and was positively interrelated to circSLC7A11 in LSCC tissues. Also, circSLC7A11 knockdown reduced the LASP1 levels, and miR-877-5p inhibitor co-transfection reversed this reduction. Rescue assays further demonstrated that circSLC7A11 accelerated LSCC through miR-877-5p/LASP1.

Conclusion

CircSLC7A11 exerted oncogenic functions in LSCC by miR-877-5p/LASP1, hinting that circSLC7A11 was a novel biomarker for LSCC.

Diagnostic and Prognostic Value of microRNAs in Patients with Laryngeal Cancer: A Systematic Review

Laryngeal squamous cell cancer (LSCC) is one of the most common malignant tumors of the head and neck region, with a poor survival rate (5-year overall survival 50-80%) as a consequence of an advanced-stage diagnosis and high recurrence rate. Tobacco smoking and alcohol abuse are the main risk factors of LSCC development. An early diagnosis of LSCC, a prompt detection of recurrence and a more precise monitoring of the efficacy of different treatment modalities are currently needed to reduce the mortality. Therefore, the identification of effective diagnostic and prognostic biomarkers for LSCC is crucial to guide disease management and improve clinical outcomes. In the past years, a dysregulated expression of small non-coding RNAs, including microRNAs (miRNAs), has been reported in many human cancers, including LSCC, and many miRNAs have been explored for their diagnostic and prognostic potential and proposed as biomarkers. We searched electronic databases for original papers that were focused on miRNAs and LSCC, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. According to the outcome, 566 articles were initially screened, of which 177 studies were selected and included in the analysis. In this systematic review, we provide an overview of the current literature on the function and the potential diagnostic and prognostic role of tissue and circulating miRNAs in LSCC.

MALAT1-miRNAs network regulate thymidylate synthase and affect 5FU-based chemotherapy

Background

The active metabolite of 5-Fluorouracil (5FU), used in the treatment of several types of cancer, acts by inhibiting the thymidylate synthase encoded by the TYMS gene, which catalyzes the rate-limiting step in DNA replication. The major failure of 5FU-based cancer therapy is the development of drug resistance. High levels of TYMS-encoded protein in cancerous tissues are predictive of poor response to 5FU treatment. Expression of TYMS is regulated by various mechanisms, including involving non-coding RNAs, both miRNAs and long non-coding RNAs (lncRNAs).

Aim

To delineate the miRNAs and lncRNAs network regulating the level of TYMS-encoded protein.

Main body

Several miRNAs targeting TYMS mRNA have been identified in colon cancers, the levels of which can be regulated to varying degrees by lncRNAs. Due to their regulation by the MALAT1 lncRNA, these miRNAs can be divided into three groups: (1) miR-197-3p, miR-203a-3p, miR-375-3p which are downregulated by MALAT1 as confirmed experimentally and the levels of these miRNAs are actually reduced in colon and gastric cancers; (2) miR-140-3p, miR-330-3p that could potentially interact with MALAT1, but not yet supported by experimental results; (3) miR-192-5p, miR-215-5p whose seed sequences do not recognize complementary response elements within MALAT1. Considering the putative MALAT1-miRNAs interaction network, attention is drawn to the potential positive feedback loop causing increased expression of MALAT1 in colon cancer and hepatocellular carcinoma, where YAP1 acts as a transcriptional co-factor which, by binding to the TCF4 transcription factor/ β-catenin complex, may increase the activation of the MALAT1 gene whereas the MALAT1 lncRNA can inhibit miR-375-3p which in turn targets YAP1 mRNA.

Conclusion

The network of non-coding RNAs may reduce the sensitivity of cancer cells to 5FU treatment by upregulating the level of thymidylate synthase.

Emerging roles of PIWI-interacting RNAs (piRNAs) and PIWI proteins in head and neck cancer and their potential clinical implications

Head and neck squamous cell carcinoma (HNSCC) are among the well-known neoplasms originating in the oral cavity, pharynx, and larynx. Despite advancements in chemotherapy, radiotherapy, and surgery, the survival rates of the patients are low, which has posed a major therapeutic challenge. A growing number of non-coding RNAs (ncRNAs), for instance, microRNAs, have been identified whose abnormal expression patterns have been implicated in HNSCC. However, more recently, several seminal research has shown that piwi-interacting RNAs (piRNAs), a promising and young class of small ncRNA, are linked to the emergence and progression of cancer. They can regulate transposable elements (TE) and gene expression through multiple mechanisms, making them potentially more powerful regulators than miRNAs. Hence, they can be more promising ncRNAs candidates for cancer therapeutic intervention. Here, we surveyed the roles and clinical implications of piRNAs and their PIWI proteins partners in tumorigenesis and associated molecular processes of cancer, with a particular focus on HNSCC, to offer a new avenue for diagnosis, prognosis, and therapeutic interventions for the malignancy, improving patient's outcomes.