LUCAT1 as an oncogene in tongue squamous cell carcinoma by targeting miR-375 expression

Long non‑coding RNA lung cancer‑associated transcript 1 regulates ferroptosis via microRNA‑34a‑5p‑mediated GTP cyclohydrolase 1 downregulation in lung cancer cells

Ferroptosis, a recently discovered type of programmed cell death triggered by excessive accumulation of iron‑dependent lipid peroxidation, is linked to several malignancies, including non‑small cell lung cancer. Long non‑coding RNAs (lncRNAs) are involved in ferroptosis; however, data on their role and mechanism in cancer therapy remains limited. Therefore, the aim of the present study was to identify ferroptosis‑associated mRNAs and lncRNAs in A549 lung cancer cells treated with RAS‑selective lethal 3 (RSL3) and ferrostatin‑1 (Fer‑1) using RNA sequencing. The results demonstrated that lncRNA lung cancer‑associated transcript 1 (LUCAT1) was significantly upregulated in lung adenocarcinoma and lung squamous cell carcinoma tissues. Co‑expression analysis of differentially expressed mRNAs and lncRNAs suggested that LUCAT1 has a crucial role in ferroptosis. LUCAT1 expression was markedly elevated in A549 cells treated with RSL3, which was prevented by co‑incubation with Fer‑1. Functionally, overexpression of LUCAT1 facilitated cell proliferation and reduced the occurrence of ferroptosis induced by RSL3 and Erastin, while inhibition of LUCAT1 expression reduced cell proliferation and increased ferroptosis. Mechanistically, downregulation of LUCAT1 resulted in the downregulation of both GTP cyclohydrolase 1 (GCH1) and ferroptosis suppressor protein 1 (FSP1). Furthermore, inhibition of LUCAT1 expression upregulated microRNA (miR)‑34a‑5p and then downregulated GCH1. These results indicated that inhibition of LUCAT1 expression promoted ferroptosis by modulating the downregulation of GCH1, mediated by miR‑34a‑5p. Therefore, the combination of knocking down LUCAT1 expression with ferroptosis inducers may be a promising strategy for lung cancer treatment.

A key regulatory loop AK4P1/miR-375/SP1 in pancreatic adenocarcinoma

Pancreatic adenocarcinoma is one of the leading lethal human cancer types and is notorious for its poor prognosis. A series of bioinformatic analyses and experimental validations were employed to explore the role and mechanism of pseudogene-derived RNAs in pancreatic adenocarcinoma. Consequently, a total of 13 upregulated and 7 downregulated pseudogene-derived RNAs in pancreatic adenocarcinoma were identified. Survival analysis revealed a statistically predictive role of AK4P1 for unfavourable prognosis of patients with pancreatic adenocarcinoma. Subcellular location analysis indicated that AK4P1 was mainly located in cytoplasm, in which AK4P1 might competitively bind to tumour suppressive miR-375 in pancreatic adenocarcinoma. Further analysis showed that SP1 was a potential downstream target gene of miR-375 in pancreatic adenocarcinoma. Intriguingly, expression determination validated that SP1 could positively regulate AK4P1 levels in pancreatic adenocarcinoma. Finally, AK4P1 might also exert its effects by interacting with oncogenic parental gene AK4 in pancreatic adenocarcinoma. Conclusively, the present study elucidated a key regulatory loop AK4P1/miR-375/SP1 in pancreatic adenocarcinoma.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

The paradigm of miRNA and siRNA influence in Oral-biome

Short nucleotide sequences like miRNA and siRNA have attracted a lot of interest in Oral-biome investigations. miRNA is a small class of non-coding RNA that regulates gene expression to provide effective regulation of post-transcription. On contrary, siRNA is 21-25 nucleotide dsRNA impairing gene function post-transcriptionally through inhibition of mRNA for homologous dependent gene silencing. This review highlights the application of miRNA in oral biome including oral cancer, dental implants, periodontal diseases, gingival fibroblasts, oral submucous fibrosis, radiation-induced oral mucositis, dental Pulp, and oral lichenoid disease. Moreover, we have also discussed the application of siRNA against the aforementioned disease along with the impact of miRNA and siRNA to the various pathways and molecular effectors pertaining to the dental diseases. The influence of upregulation and downregulation of molecular effector post-treatment with miRNA and siRNA and their impact on the clinical setting has been elucidated. Thus, the mentioned details on application of miRNA and siRNA will provide a novel gateway to the scholars to not only mitigate the long-lasting issue in dentistry but also develop new theragnostic approaches.

Mutation-associated transcripts reconstruct the prognostic features of oral tongue squamous cell carcinoma

Tongue squamous cell carcinoma is highly malignant and has a poor prognosis. In this study, we aimed to combine whole-genome sequencing, whole-genome methylation, and whole-transcriptome analyses to understand the molecular mechanisms of tongue squamous cell carcinoma better. Oral tongue squamous cell carcinoma and adjacent normal tissues from five patients with tongue squamous cell carcinoma were included as five paired samples. After multi-omics sequencing, differentially methylated intervals, methylated loop sites, methylated promoters, and transcripts were screened for variation in all paired samples. Correlations were analyzed to determine biological processes in tongue squamous cell carcinoma. We found five mutated methylation promoters that were significantly associated with mRNA and lncRNA expression levels. Functional annotation of these transcripts revealed their involvement in triggering the mitogen-activated protein kinase cascade, which is associated with cancer progression and the development of drug resistance during treatment. The prognostic signature models constructed based on WDR81 and HNRNPH1 and combined clinical phenotype-gene prognostic signature models showed high predictive efficacy and can be applied to predict patient prognostic risk in clinical settings. We identified biological processes in tongue squamous cell carcinoma that are initiated by mutations in the methylation promoter and are associated with the expression levels of specific mRNAs and lncRNAs. Collectively, changes in transcript levels affect the prognosis of tongue squamous cell carcinoma patients.

Dysregulation and implications of lncRNAs and miRNAs in oral tongue squamous cell carcinoma: In reply with emphasis on the role of ceRNAs

Increasing evidence indicates that long noncoding RNAs (lncRNAs) as competing endogenous RNAs (ceRNAs) competitively sequestering microRNAs (miRNAs) participate in biological processes of oral tongue squamous cell carcinoma (TSCC). In this Letter, the ceRNA regulatory networks consisting of lncRNA/miRNA/mRNA axes in TSCC were summarized. Dysregulated profiles containing 33 lncRNAs and 31 miRNAs were identified by cancer-associated phenotypes verification. Almost all the lncRNAs could exert the oncogenic roles to sponge miRNAs and regulate targeting mRNA expression, thereby modulating cell proliferation, cell cycle, apoptosis, invasion, migration, metastasis, epithelial-mesenchymal transition, as well as chemoresistance. Significantly, the implications of functional ceRNAs deactivated in tumor cells contribute to the exploitation of novel diagnostic and therapeutic strategies for TSCC.

E2F transcription factor 1 is involved in the phenotypic modulation of esophageal squamous cell carcinoma cells via microRNA-375

E2F family of transcription factors modulates multiple cellular functions associated with cell cycle and apoptosis. Here, we focused on the relevance of E2F1 to esophageal squamous cell carcinoma (ESCC) and identification of E2F1-mediated network in this study. Query of Gene Expression Omnibus database revealed that E2F1 was the core gene that was upregulated in ESCC. E2F1 downregulation inhibited ESCC cell activity. microRNA (miR)-375 was confirmed to be a downstream target of E2F1. E2F1 bound to miR-375 promoter and inhibited miR-375 transcription. Moreover, miR-375 inhibitor mitigated the repressive impacts of si-E2F1 on ESCC cells in part. Further study showed that sestrin 3 (SESN3) could interact with miR-375, and its knockdown annulled the stimulative effect of miR-375 inhibitor on ESCC development. Finally, E2F1 and SESN3 downregulation inhibited the phosphatidylinositol 3 kinase (PI3K)/AKT pathway activity in cells, while miR-375 inhibitor promoted PI3K/AKT pathway activation. These findings suggest that E2F1 inhibited miR-375 expression and promoted SESN3 expression to activate the PI3K/AKT pathway in ESCC.

LUCAT1 as an oncogene in tongue squamous cell carcinoma by targeting miR-375 expression

Emerging studies suggested that lncRNAs play a crucial molecular role in cancer development and progression. LncRNA LUCAT1 has been proved as oncogenic molecular in lung cancer, glioma, osteosarcoma, renal carcinoma and oesophageal squamous cell carcinoma. However, its roles and function mechanisms in tongue squamous cell carcinoma (TSCC) are still unknown. We showed that the expression of LUCAT1 was up‐regulated in the TSCC cells and tissues and the higher LUCAT1 expression was associated with the poor overall survival (OS). Knockdown expression of LUCAT1 suppressed TSCC cell proliferation, cycle and migration. In addition, we demonstrated that miR‐375 overexpression inhibited the luciferase activity of LUCAT1 wild‐type and knockdown LUCAT1 promoted the miR‐375 expression in TSCC cell. Furthermore, we indicated that miR‐375 expression was down‐regulated in the TSCC cell lines and tissues and the lower expression of miR‐375 was associated with poor OS. The expression of miR‐375 was inversely correlated with LUCAT1 expression in the TSCC tissues. Knockdown LUCAT1 promoted TSCC cell proliferation, cell cycle and migration partly through regulating miR‐375 expression. In summary, this study suggested the tumorigenic effect of lncRNA LUCAT1 in TSCC cells by targeting miR‐375 expression.