A Pleiotropic Role of Long Non-Coding RNAs in the Modulation of Wnt/β-Catenin and PI3K/Akt/mTOR Signaling Pathways in Esophageal Squamous Cell Carcinoma: Implication in Chemotherapeutic Drug Response

Clinical Significance of LINC00261 in the Pathogenesis of Pancreatic, Colorectal, Hepatocellular, and Gallbladder Cancer

Pancreatic (PC), colorectal (CRC), hepatocellular (HCC), and gallbladder (GC) cancers together account for nearly 20% of all cancer cases. However, specific biomarkers and therapeutic targets for these cancers are lacking. Diagnosing these cancers early and providing timely, appropriate treatment to improve patient outcomes is crucial. In this context, previous studies, including ours, have highlighted the potential of non-coding RNAs, particularly long non-coding RNAs (lncRNAs), in diagnosing and prognosis of various cancers. This review focuses on the mechanistic role of the recently identified lncRNA LINC00261 in PC, CRC, HCC, and GC. Our comprehensive literature analysis revealed that LINC00261 functions as a tumor suppressor, and its reduced expression is associated with larger tumor size, advanced tumor-node-metastasis (TNM) stages, lymphatic metastasis, and poorer overall survival rates. Additionally, we discovered that LINC00261 acts as a molecular sponge for miRNAs, such as miR-550a-3p, miR-23a-3p, miR-148a, miR-324-3p, and miR-105-5p, regulating critical cancer-related signaling pathways, including PI3K/Akt/mTOR, Protein kinase B, and Mammalian target of rapamycin (mTOR). Further bioinformatic analysis revealed that LINC00261 regulates key cellular processes, such as protein-DNA complex formation, ribonuclease complex activity, histone deacetylase complexes, and nuclear matrix interactions. Overall, we believe that LINC00261 holds significant promise as a future biomarker and, when combined with existing treatment strategies, may enhance cancer patient care and survival.

Etomidate suppresses proliferation, migration, invasion, and glycolysis in esophageal cancer cells via PI3K/AKT pathway inhibition

Esophageal cancer remains a formidable challenge in oncology, characterized by its poor prognosis and limited therapeutic options. Recent investigations have unveiled the potential of repurposing existing drugs for cancer treatment. Notably, etomidate, an anesthetic agent traditionally used for inducing general anesthesia, has emerged as a promising candidate demonstrating significant anticancer properties across various tumor types. The present study aims to investigate the effects of etomidate on esophageal carcinoma cells, with a specific focus on its ability to modulate the PI3K/AKT signaling pathway and inhibit tumor proliferation. This study employed both in vitro and in vivo methodologies to assess the effects of etomidate on esophageal cancer cells. In vitro experiments evaluated the effects of etomidate on cell proliferation, migration, invasion, and glycolytic processes. An in vivo xenograft mouse model was established to investigate the therapeutic potential of etomidate on tumor growth and assess its impact on the PI3K/AKT signaling pathway in a physiologically relevant context. Etomidate demonstrated a significant inhibitory effect on the proliferation, migration, invasion, and glycolytic capacity of esophageal cancer cells. This multifaceted suppression of tumorigenic properties was closely associated with the inhibition of the PI3K/AKT pathway, as evidenced by reduced phosphorylation levels of PI3K and AKT. In vivo studies using a murine model of esophageal cancer corroborated these findings. Etomidate administration resulted in a substantial reduction in tumor volume and mass, accompanied by increased apoptotic activity and the inhibition of the PI3K/AKT pathway within the tumor tissue. This study demonstrates etomidate's potent inhibition of esophageal cancer progression through suppression of the PI3K/AKT pathway. These promising results warrant further clinical investigation of etomidate as a potential therapeutic strategy for esophageal cancer.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-024-00661-y.

SLC39A14 promotes the development of esophageal squamous cell carcinoma through PI3K/Akt/mTOR signaling pathway

OBJECTIVES

This study aims to investigate the expression of solute carrier family 39 member 14 (SLC39A14) in esophageal squamous cell carcinoma (ESCC) tissues and its prognosis, as well as the impact of SLC39A14 expression on the biological behavior of ESCC cells and associated mechanisms.

METHODS

Bioinformatics analysis was utilized to compare the differential expression of SLC39A14 mRNA between esophageal cancer tissues and adjacent non-cancerous tissues. Immunohistochemistry was employed to evaluate SLC39A14 protein expression in human ESCC tissues and normal esophageal tissues, followed by an analysis of its association with clinicopathological parameters in esophageal cancer patients. Through cell proliferation, migration, invasion, and Western blot assays, we deeply evaluated the specific effects of SLC39A14 gene knockdown (or overexpression) on ESCC cells and explored its potential biological functions in ESCC. Subsequently, we validated the role of SLC39A14 in ESCC in a xenograft model. Furthermore, LY294002 drug intervention was used to verify the regulatory effect of SLC39A14 on PI3K/Akt/mTOR signaling pathway.

RESULTS

Both mRNA and protein levels of SLC39A14 were significantly elevated in tumor tissues from ESCC patients compared to adjacent normal tissues. Notably, higher levels of SLC39A14 expression positively correlated with ESCC tumor size (p = 0.010) and clinical T stage (p = 0.025), while exhibiting a negative correlation with overall patient survival rates (p = 0.023). In vitro experiments demonstrated that knocking down SLC39A14 significantly inhibited cell proliferation, migration and invasion. In vivo study showed that SLC39A14 facilitated progression within murine models bearing ESCC tumors. Mechanistic analyses suggested that pro-carcinogenic effects exerted by SLC39A14 are mediated through activation of the PI3K/Akt/mTOR signaling pathway.

CONCLUSIONS

Our findings suggest that SLC39A14 may serve as a potential biomarker for ESCC due to its pro-oncogenic role during ESCC progression.

miRNA signatures affecting the survival outcome in distant metastasis of triple-negative breast cancer

Triple-negative breast cancer (TNBC) constitutes for 10-15% of all breast cancer cases. Tumor heterogeneity, high invasiveness, distant metastasis, lack of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 expression contribute to TNBC associated with poor overall survival outcomes amongst diseased individuals. The disparity in clinico-pathological and metastatic patterns to distant sites has substantially enhanced the incidences of tumor recurrence. Survival outcomes amongst metastatic TNBC patients are worse in comparison to non-metastatic TNBC counterparts. MicroRNAs (miRNAs) have emerged as significant drivers to function either as oncogene or tumor suppressors by exerting modulating effects on the expression of target genes in the TNBC tumor microenvironment. The pleiotropic nature of miRNAs expands their preclinical and clinical utility in combating both metastatic and non-metastatic TNBC cases and thereby improves their survival outcomes. The present review article aims to highlight the varying survival outcomes in metastatic and non-metastatic TNBC cases. The present review article emphasizes the therapeutic and prognostic potential of miRNAs in TNBC to improve survival outcomes by retarding distant metastasis to lung, bone, brain, and lymph nodes.

Unraveling the role of LncRNAs in glioblastoma progression: insights into signaling pathways and therapeutic potential

Glioblastoma (GBM) is one of the most aggressive types of brain cancer, characterized by its poor prognosis and low survival rate despite current treatment modalities. Because GBM is lethal, clarifying the pathogenesis's underlying mechanisms is important, which are still poorly understood. Recent discoveries in the fields of molecular genetics and cancer biology have demonstrated the critical role that non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), play in the molecular pathophysiology of GBM growth. LncRNAs are transcripts longer than 200 nucleotides that do not encode proteins. They are significant epigenetic modulators that control gene e expression at several levels. Their dysregulation and interactions with important signaling pathways play a major role in the malignancy and development of GBM. The increasing role of lncRNAs in GBM pathogenesis is thoroughly examined in this review, with particular attention given to their regulation mechanisms in key signaling pathways such as PI3K/AKT, Wnt/β-catenin, and p53. It also looks into lncRNAs' potential as new biomarkers and treatment targets for GBM. In addition, the study discusses the difficulties in delivering lncRNA-based medicines across the blood-brain barrier and identifies areas that need more research to advance lncRNA-oriented treatments for this deadly cancer.

LncRNA taurine upregulated gene 1 in liver disease

Long non-coding RNAs (lncRNAs) are RNA sequences exceeding 200 nucleotides in length that lack protein-coding capacity and participate in diverse biological processes in the human body, particularly exerting a pivotal role in disease surveillance, diagnosis, and progression. Taurine upregulated gene 1 (TUG1) is a versatile lncRNA, and recent studies have revealed that the aberrant expression or function of TUG1 is intricately linked to the pathogenesis of liver diseases. Consequently, we have summarized the current understanding of the mechanism of TUG1 in liver diseases such as liver fibrosis, fatty liver, cirrhosis, liver injury, hepatitis, and liver cancer. Moreover, mounting evidence suggests that interventions targeting TUG1 or its downstream pathways may hold therapeutic promise for liver diseases. This review elucidates the characteristics, mechanisms, and targets of TUG1 in liver diseases, offering a theoretical basis for the prevention, diagnosis, treatment, and prognostic biomarkers of liver diseases.

Non‑coding RNA: A promising diagnostic biomarker and therapeutic target for esophageal squamous cell carcinoma (Review)

Esophageal cancer (EC) is a common form of malignant tumor in the digestive system that is classified into two types: Esophageal squamous cell carcinomas (ESCC) and esophageal adenocarcinoma. ESCC is known for its early onset of symptoms, which can be difficult to identify, as well as its rapid progression and tendency to develop drug resistance to chemotherapy and radiotherapy. These factors contribute to the high incidence of disease and low cure rate. Therefore, a diagnostic biomarker and therapeutic target need to be identified for ESCC. Non-coding RNAs (ncRNAs) are a class of molecules that are transcribed from DNA but do not encode proteins. Initially, ncRNAs were considered to be non-functional segments generated during transcription. However, with advancements in high-throughput sequencing technologies in recent years, ncRNAs have been associated with poor prognosis, drug resistance and progression of ESCC. The present study provides a comprehensive overview of the biogenesis, characteristics and functions of ncRNAs, particularly focusing on microRNA, long ncRNAs and circular RNAs. Furthermore, the ncRNAs that could potentially be used as diagnostic biomarkers and therapeutic targets for ESCC are summarized to highlight their application value and prospects in ESCC.

Comprehensive landscape and future perspectives of non-coding RNAs in esophageal squamous cell carcinoma, a bibliometric analysis from 2008 to 2023

Objectives: Summarize the progress and hot topic evolution of non-coding RNAs (ncRNAs) research in esophageal squamous cell carcinoma (ESCC) in recent years and predict future research directions. Methods: Relevant articles from the Web of Science until 31 October 2023 were obtained. Bibliometric analysis of included articles was performed using software (VOSviewer, CiteSpace, and Bibliometrix). The volume and citation of publications, as well as the country, institution, author, journal, keywords of the articles were used as variables to analyze the research trends and hot spot evolution. Results: 1,118 literature from 2008 to 2023 were retrieved from database, with 25 countries/regions, 793 institutions, 5,426 authors, 261 journals involved. Global cooperation was centered on China, Japan, and the United States. Zhengzhou University, an institution from China, had the highest publication. The most prolific author was Guo Wei, and the most prolific journal was Oncology Letters. Analysis of keywords revealed that the research in this field revolved around the role of ncRNAs in the occurrence, development, diagnosis, treatment, and prognosis of ESCC, mainly including micro RNAs, long non-coding RNAs, and then circular RNAs. Conclusion: Overall, research on ncRNAs in ESCC remains strong. Previous research has mainly focused on the basic research, with a focus on the mechanism of ncRNAs in the occurrence, development, diagnosis, treatment, and prognosis of ESCC. Combining current research with emerging disciplines to further explore its mechanisms of action or shifting the focus of research from preclinical research to clinical research based on diagnosis, treatment, and prognosis, will be the main breakthrough in this field in the future.

Long noncoding RNA SNHG6 silencing sensitized esophageal cancer cells to 5-FU via EZH2/STAT pathway

Chemotherapy was the main treatment method for esophageal cancer (EC) patients. However, chemotherapy resistance due to multiple factors is a major barrier to EC treatment. For investigating how small nucleolar RNA host gene 6 (SNHG6) affected the 5-fluorouracil (5-FU) resistance in EC as well as its possible molecular mechanism. This work conducted cell viability assay, clone formation, scratch assays together with cell apoptosis for evaluating the roles of SNHG6 and enhancer of zeste homolog 2 (EZH2, the histone-lysine N-methyltransferase). Relevant molecular mechanism was identified by RT-qPCR analysis together with Western-blot (WB) assays. Our data showed that SNHG6 expression increased in EC cells. SNHG6 promotes colony formation and migration, whereas suppresses EC cell apoptosis. SNHG6 silencing markedly promoted 5-FU-mediated suppression on KYSE150 and KYSE450 cells. Additional mechanism studies showed that SNHG6 modulating STAT3 and H3K27me3 via promoting EZH2 level. Similar to the function of SNHG6, abnormal expression of EZH2 promotes the malignancy of EC and intensifies its resistance to 5-FU. In addition, overexpression of EZH2 abolished the role of SNHG6 silencing in 5-FU sensitivity in EC cells. SNHG6 overexpression promoted malignancy of EC and increased EC cell resistance to 5-FU. Besides, further molecular mechanism studies provided a novel regulatory pathways that SNHG6 knockdown promoted EC cell sensitivity to 5-FU by modulating STAT3 and H3K27me3 via promoting EZH2 expression.

LINC00324 promotes cell proliferation and metastasis of esophageal squamous cell carcinoma through sponging miR-493-5p via MAPK signaling pathway

Long non-coding RNAs have been demonstrated to promote proliferation and metastasis via regulating the miRNA/mRNA regulatory axis in various malignancies. Based on our preliminary study, we investigated the mechanism of LINC00324 through miR-493-5p/MAPK1 in esophageal squamous cell carcinoma (ESCC) pathogenesis. Herein, we confirmed that LINC00324 is significantly upregulated in ESCC primary cells and esophageal squamous cell carcinoma cell line KYSE-70. Silencing of LINC00324 modulates cell proliferation markers, p21, p27, c-Myc, and Cyclin D1 and epithelial-to-mesenchymal transition markers, slug, snail, ZEB1, vimentin, ZO-1, and E-cadherin protein expression in ESCC. Through bioinformatics and dual luciferase reporter assays, we identified miR-493-5p as the direct target molecule of LINC00324. We further revealed that LINC00324 negatively regulates miR-493-5p expression in ESCC. Moreover, our multiple gain-and loss-of-functional experiments proved that a combination of miR-493-5p and LINC00324 significantly rescued ESCC cell proliferation and metastatic phenotypes. Mechanistically, LINC00324 promotes ESCC pathogenesis by acting as a competing endogenous RNA and sponges miR-493-5p activity thereby activating MAPK1 during ESCC progression. We believe that targeting LINC00324 /miR-493-5p/MAPK1 axis may provide new therapeutic avenues for ESCC.

Epigenetic regulation of gastrointestinal cancers mediated by long non-coding RNAs

Long noncoding RNAs (lncRNAs), as well-known modulator of the epigenetic processes, have been shown to contribute to normal cellular physiological and pathological conditions such as cancer. Through the interaction with epigenetic regulators, an aberrant regulation of gene expression can be resulted due to their dysregulation, which in turn, can be involved in tumorigenesis. In the present study, we reviewed the lncRNAs' function and mechanisms that contributed to aberrant epigenetic regulation, which is directly related to gastrointestinal cancer (GI) development and progression. Findings indicated that epigenetic alterations may involve in tumorigenesis and are valuable biomarkers in case of diagnosing, assessing of risk factors, and predicting of GI cancers. This review summarized the accumulated evidence for biological and clinical application to use lncRNAs in GI cancers, including colorectal, gastric, oral, liver, pancreatic and oesophageal cancer.