CircRNA-001241 Mediates Sorafenib Resistance of Hepatocellular Carcinoma Cells by Sponging miR-21-5p and Regulating TIMP3 Expression

circ_0006089 facilitates gastric cancer progression and oxaliplatin resistance via miR-217/NRP1

BACKGROUND

Oxaliplatin (OXA) is a vital tool in the chemotherapy of gastric cancer (GC) patients. Circular RNAs (circRNAs) are a group of non-coding RNAs that have been associated with tumorigenesis. Nevertheless, the function of circRNAs in OXA resistance of GC is unknown.

METHODS

Circ_0006089/miR-217/NRP1 were elucidated through qRT-PCR in GC OXA-tolerant tissues and cell lines. OXA half-inhibitory concentration (IC50) was quantified by MTT assay. RNA pull-down and luciferase reporter tests were applied to characterize the interaction between circ_0006089 and miR-217, miR-217 and NRP1 in GC cells.

RESULTS

The findings disclosed that circ_0006089 and NRP1 was heightened whereas miR-217 was dramatically declined in OXA-tolerant GC tissues and cell lines. OXA resistance was reduced and the proliferation, migration and invasion ability of OXA cells were diminished after silencing circ_0006089. In addition, circ_0006089 raised OXA resistance by sponging miR-217. Further studies revealed that miR-217 bound to NRP1 and weakened OXA resistance. In addition, it was found that circ_0006089 accelerated GC progression and OXA resistance by upregulating NRP1 expression via sponging miR-217.

CONCLUSION

Circ_0006089 regulated OXA resistance in GC cells through miR-217/NRP1 axis, implying it was a promising biomarker for GC therapy.

microRNA 21 and long non-coding RNAs interplays underlie cancer pathophysiology: A narrative review

Non-coding RNAs (ncRNAs) are a diverse group of functional RNA molecules that lack the ability to code for proteins. Despite missing this traditional role, ncRNAs have emerged as crucial regulators of various biological processes and have been implicated in the development and progression of many diseases, including cancer. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are two prominent classes of ncRNAs that have emerged as key players in cancer pathophysiology. In particular, miR-21 has been reported to exhibit oncogenic roles in various forms of human cancer, including prostate, breast, lung, and colorectal cancer. In this context, miR-21 overexpression is closely associated with tumor proliferation, growth, invasion, angiogenesis, and chemoresistance, whereas miR-21 inactivation is linked to the regression of most tumor-related processes. Accordingly, miR-21 is a crucial modulator of various canonical oncogenic pathways such as PTEN/PI3K/Akt, Wnt/β-catenin, STAT, p53, MMP2, and MMP9. Moreover, interplays between lncRNA and miRNA further complicate the regulatory mechanisms underlying tumor development and progression. In this regard, several lncRNAs have been found to interact with miR-21 and, by functioning as competitive endogenous RNAs (ceRNAs) or miRNA sponges, can modulate cancer tumorigenesis. This work presents and discusses recent findings highlighting the roles and pathophysiological implications of the miR-21-lncRNA regulatory axis in cancer occurrence, development, and progression. The data collected indicate that specific lncRNAs, such as MEG3, CASC2, and GAS5, are strongly associated with miR-21 in various types of cancer, including gastric, cervical, lung, and glioma. Indeed, these lncRNAs are well-known tumor suppressors and are commonly downregulated in different types of tumors. Conversely, by modulating various mechanisms and oncogenic signaling pathways, their overexpression has been linked with preventing tumor formation and development. This review highlights the significance of these regulatory pathways in cancer and their potential for use in cancer therapy as diagnostic and prognostic markers.

The role of competing endogenous RNA network in the development of hepatocellular carcinoma: potential therapeutic targets

The current situation of hepatocellular carcinoma (HCC) management is challenging due to its high incidence, mortality, recurrence and metastasis. Recent advances in gene genetic and expression regulation have unveiled the significant role of non-coding RNA (ncRNA) in various cancers. This led to the formulation of the competing endogenous RNA (ceRNA) hypothesis, which posits that both coding RNA and ncRNA, containing miRNA response elements (MRE), can share the same miRNA sequence. This results in a competitive network between ncRNAs, such as lncRNA and mRNA, allowing them to regulate each other. Extensive research has highlighted the crucial role of the ceRNA network in HCC development, impacting various cellular processes including proliferation, metastasis, cell death, angiogenesis, tumor microenvironment, organismal immunity, and chemotherapy resistance. Additionally, the ceRNA network, mediated by lncRNA or circRNA, offers potential in early diagnosis and prevention of HCC. Consequently, ceRNAs are emerging as therapeutic targets for HCC. The complexity of these gene networks aligns with the multi-target approach of traditional Chinese medicine (TCM), presenting a novel perspective for TCM in combating HCC. Research is beginning to show that TCM compounds and prescriptions can affect HCC progression through the ceRNA network, inhibiting proliferation and metastasis, and inducing apoptosis. Currently, the lncRNAs TUG1, NEAT1, and CCAT1, along with their associated ceRNA networks, are among the most promising ncRNAs for HCC research. However, this field is still in its infancy, necessitating advanced technology and extensive basic research to fully understand the ceRNA network mechanisms of TCM in HCC treatment.

Synthetic miR-21 decoy circularized by tRNA splicing mechanism inhibited tumorigenesis in glioblastoma in vitro and in vivo models

Glioblastoma multiforme (GBM) is the deadliest primary central nervous system tumor. miRNAs (miRs), a class of non-coding RNAs, are considered pivotal post-transcriptional regulators of cell signaling pathways. miR-21 is a reliable oncogene that promotes tumorigenesis of cancer cells. We first performed an in silico analysis on 10 microarray datasets retrieved from TCGA and GEO databases to elucidate top differentially expressed miRs. Furthermore, we generated a circular miR-21 decoy, CM21D, using the tRNA-splicing mechanism in GBM cell models, U87 and C6. The inhibitory efficacy of CM21D with that of a linear form, LM21D, was compared under in vitro conditions and an intracranial C6 rat glioblastoma model. miR-21 significantly overexpressed in GBM samples and confirmed in GBM cell models using qRT-PCR. CM21D was more efficient than LM21D at inducing apoptosis, inhibiting cell proliferation and migration, and interrupting the cell cycle by restoring the expression of miR-21 target genes at RNA and protein levels. Moreover, CM21D suppressed tumor growth more effectively than LM21D in the C6-rat GBM model (p < 0.001). Our findings validate miR-21 as a promising therapeutic target for GBM. The introduced CM21D by sponging miR-21 reduced tumorigenesis of GBM and can be considered a potential RNA-base therapy to inhibit cancers.

The interplay between noncoding RNAs and drug resistance in hepatocellular carcinoma: the big impact of little things

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death in people, and a common primary liver cancer. Lacking early diagnosis and a high recurrence rate after surgical resection, systemic treatment is still an important treatment method for advanced HCC. Different drugs have distinct curative effects, side effects and drug resistance due to different properties. At present, conventional molecular drugs for HCC have displayed some limitations, such as adverse drug reactions, insensitivity to some medicines, and drug resistance. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), have been well documented to be involved in the occurrence and progression of cancer. Novel biomarkers and therapeutic targets, as well as research into the molecular basis of drug resistance, are urgently needed for the management of HCC. We review current research on ncRNAs and consolidate the known roles regulating drug resistance in HCC and examine the potential clinical applications of ncRNAs in overcoming drug resistance barriers in HCC based on targeted therapy, cell cycle non-specific chemotherapy and cell cycle specific chemotherapy.

Lnc-TMEM132D-AS1 as a potential therapeutic target for acquired resistance to osimertinib in non-small-cell lung cancer

Acquired resistance is a major obstacle to the therapeutic efficacy of osimertinib in non-small-cell lung cancer (NSCLC). Current knowledge about the role of long non-coding RNAs (lncRNAs) in this phenomenon is insufficient. In this study, we screened the differentially expressed lncRNAs between osimertinib-sensitive and -resistant NSCLC cell lines, and determined that lnc-TMEM132D-AS1 was significantly upregulated in osimertinib-resistant NSCLC cells, as well as in the plasma of osimertinib-resistant NSCLC patients. Lnc-TMEM132D-AS1 markedly decreased the osimertinib sensitivity of NSCLC cells. After osimertinib exposure, it increased the cell proliferation and colony formation, decreased the cell apoptosis, and induced M2/G-phase cell cycle arrest. After identifying its cytoplasmic localization, a functional lnc-TMEM132D-AS1-miRNA-mRNA interaction network and a protein-protein interaction (PPI) network were constructed to analyze its putative target genes and biological functions. Lnc-TMEM132D-AS1 could directly bind to miR-766-5p and lead to the upregulation of ectonucleoside triphosphate diphosphohydrolase-1 (ENTPD1), resulting in an increase in cell proliferation. Moreover, upregulated ENTPD1 was also associated with enhanced tumor infiltration of immunosuppressive cells and poor prognosis in NSCLC patients. In summary, lnc-TMEM132D-AS1 plays a crucial role in osimertinib resistance. It may serve as a prognostic biomarker and a potential therapeutic target for acquired resistance to osimertinib in NSCLC.