OIP5-AS1 contributes to tumorigenesis in hepatocellular carcinoma by miR-300/YY1-activated WNT pathway

Natural products and long noncoding RNA signatures in gallbladder cancer: a review focuses on pathogenesis, diagnosis, and drug resistance

Gallbladder cancer (GBC) is an aggressive and lethal malignancy with a poor prognosis. Long noncoding RNAs (lncRNAs) and natural products have emerged as key orchestrators of cancer pathogenesis through widespread dysregulation across GBC transcriptomes. Functional studies have revealed that lncRNAs interact with oncoproteins and tumor suppressors to control proliferation, invasion, metastasis, angiogenesis, stemness, and drug resistance. Curcumin, baicalein, oleanolic acid, shikonin, oxymatrine, arctigenin, liensinine, fangchinoline, and dioscin are a few examples of natural compounds that have demonstrated promising anticancer activities against GBC through the regulation of important signaling pathways. The lncRNAs, i.e., SNHG6, Linc00261, GALM, OIP5-AS1, FOXD2-AS1, MINCR, DGCR5, MEG3, GATA6-AS, TUG1, and DILC, are key players in regulating the aforementioned processes. For example, the lncRNAs FOXD2-AS1, DILC, and HOTAIR activate oncogenes such as DNMT1, Wnt/β-catenin, BMI1, and c-Myc, whereas MEG3 and GATA6-AS suppress the tumor proteins NF-κB, EZH2, and miR-421. Clinically, specific lncRNAs can serve as diagnostic or prognostic biomarkers based on overexpression correlating with advanced TNM stage, metastasis, chemoresistance, and poor survival. Therapeutically, targeting aberrant lncRNAs with siRNA or antisense oligos disrupts their oncogenic signaling and inhibits GBC progression. Overall, dysfunctional lncRNA regulatory circuits offer multiple avenues for precision medicine approaches to improve early GBC detection and overcome this deadly cancer. They have the potential to serve as novel biomarkers as they are detectable in bodily fluids and tissues. These findings enhance gallbladder treatments, mitigating resistance to chemo- and radiotherapy.

Research progress on the role of RNA N6-methyladenosine methylation in HCV infection

Hepatitis C virus (HCV) is a positive-stranded RNA virus causing chronic liver diseases. The chemical modification of RNA is a research hotspot in related fields in recent years, including the methylation and acetylation of adenine, guanine, cytosine and other bases, among which methylation is the most important modification form. m⁶A (N⁶-methyladenosine), as the most abundant RNA modification form, plays an important role in HCV virus infection by modifying viral RNA and cell transcripts. This review aims to summarize the current knowledge on the roles of m⁶A modification in HCV infection, and discuss the research prospect.

Tetramethylpyrazine and Astragaloside IV have synergistic effects against spinal cord injury-induced neuropathic pain via the OIP5-AS1/miR-34a/Sirt1/NF-κB axis

BACKGROUND

Both Tetramethylpyrazine (TMPZ) and Astragaloside IV (AGS-IV) can ameliorate neuronal apoptosis and neuroinflammation in CNS diseases. This study revolves around the underlying mechanism of TMPZ and AGS-IV in spinal cord injury (SCI)-associated neuropathic pain (NP).

MATERIALS AND METHODS

An in-vivo NP model was constructed in Sprague-Dawley (SD) rats via SCI. qRT-PCR was employed to detect OIP5-AS1 and miR-34a. The paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) of the rats were evaluated. Neuronal apoptosis in the spinal cord of rats was examined by Nissl staining and TUNEL staining. The interactions between OIP5-AS1 and miR-34a as well as miR-34a and Sirt1 were investigated through dual luciferase assay and RIP assay. The protein expressions of Bad, Bax, Caspase-3, iNOS, COX2, NF-κB, and Sirt1 were examined by western blot.

RESULTS

TMPZ and AGS-IV combination relieved behavioral symptoms of neuropathic pain in the SCI rat model, enhanced the levels of OIP5-AS1 and Sirt1, and lowered the profile of miR-34a. OIP5-AS1 downregulation weakened the neuroprotective function of TMPZ and AGS-IV in SCI rats and reversed their anti-inflammatory and anti-apoptotic effects on LPS-elicited primary spinal cord neurons. miR-34a was identified as a target of OIP5-AS1. Upregulated miR-34a partly abated the protective functions of TMPZ and AGS-IV in primary spinal cord neurons. Additionally, miR-34a targeted and repressed Sirt1, thus activating the NF-κB pathway and inflammatory reactions. Sirt1 inhibition reduced the protective effects mediated by OIP5-AS1.

CONCLUSION

TMPZ and AGS-IV ameliorate SCI-elicited NP via the OIP5-AS1/miR-34a/Sirt1/NF-κB pathway.

circUBAP2 inhibits cisplatin resistance in gastric cancer via miR-300/KAT6B axis

Circular RNAs play an important role in regulating cisplatin (CDDP) resistance in gastric cancer (GC). The aim of this study was to examine the role and downstream regulation mechanisms of circUBAP2 in CDDP resistance of GC. The expression of circUBAP2 in GC and its correlation with the prognosis of GC patients were analyzed using qRT-PCR and the Kaplan-Meier plotter database. The effects of circUBAP2 on cell viability and apoptosis were investigated by Cell Counting Kit 8 assay and flow cytometry. The expressions of drug-resistance-related proteins, P-gp and MRP1, were detected by Western blot. The interaction between circUBAP2 and miR-300 was confirmed using RNA pulldown and immunoprecipitation assays. The correlation between miR-300 and KAT6B was assessed using dual-luciferase reporter assay and TCGA database. CircUBAP2 was downregulated in GC tissues and cell lines, and correlated with the poor prognosis of GC. In addition, circUBAP2 enhanced apoptosis but inhibited cell viability and the CDDP resistance of GC cells in vitro . CircUBAP2 acted as a sponge of microRNA-300 (miR-300) and was negatively correlated with miR-300. Moreover, the upregulation of miR-300 partially removed the effects of circUBAP2 on cell viability, apoptosis and CDDP resistance in GC cells. MiR-300 directly targeted to lysine acetyltransferase 6B (KAT6B), and KAT6B overexpression showed an inhibitory effect on cell viability and CDDP resistance of GC cells. Our data suggested that the circUBAP2/miR-300/KAT6B axis was involved in the inhibition of CDDP resistance in GC, which might provide a novel focus for potential GC therapy.

Long non-coding RNA OIP5-AS1 (Cyrano): A context-specific regulator of normal and disease processes

Long non-coding (lnc) RNAs have been implicated in a plethora of normal biological functions, and have also emerged as key molecules in various disease processes. OIP5-AS1, also commonly known by the alias Cyrano, is a lncRNA that displays broad expression across multiple tissues, with significant enrichment in particular contexts including within the nervous system and skeletal muscle. Thus far, this multifaceted lncRNA has been found to have regulatory functions in normal cellular processes including cell proliferation and survival, as well as in the development and progression of a myriad disease states. These widespread effects on normal and disease states have been found to be mediated through context-specific intermolecular interactions with dozens of miRNAs and proteins identified to date. This review explores recent studies to highlight OIP5-AS1's contextual yet pleiotropic roles in normal homeostatic functions as well as disease oetiology and progression, which may influence its utility in the generation of future theranostics.

The circular RNA hsa_circ_000780 as a potential molecular diagnostic target for gastric cancer

Background

The present study aimed to identify a specific circular RNA (circRNA) for early diagnosis of gastric cancer (GC).

Methods

Totally 82 patients with GC, 30 with chronic nonatrophic gastritis and 30 with chronic atrophic gastritis were included in this study. Four of the 82 GC patients were selected for screening. Total RNA from malignant and adjacent tissue samples was extracted, and circRNAs in four patients were screened. According to the screening results, the eight most upregulated and downregulated circRNAs with a statistically significant association with GC were identified by real-time fluorescent quantitative polymerase chain reaction (PCR). Then, the most regulated circRNA was selected for further sensitivity and specificity assessments. CircRNA expression was examined by quantitative reverse transcriptase PCR in 78 GC (21 and 57 early and advanced GC, respectively) and adjacent tissue samples, as well as in gastric fluid samples from 30 patients with chronic nonatrophic gastritis, 30 with chronic atrophic gastritis, and 78 GC.

Results

A total of 445 circRNAs, including 69 upregulated and 376 downregulated circRNAs, showed significantly altered expression in GC tissue samples. Hsa_circ_000780 was significantly downregulated in 80.77% of GC tissue samples, with levels in GC tissue samples correlating with tumor size, tumor stage, T stage, venous invasion, carcinoembryonic antigen amounts, and carbohydrate antigen 19–9 levels. Strikingly, this circRNA was found in the gastric fluid of patients with early and advanced GC.

Conclusions

The present study uncovered a new circRNA expression profile in human GC, with hsa_circ_000780 significantly downregulated in GC tissue and gastric fluid specimens. These findings indicate that hsa_circ_000780 should be considered a novel biomarker for early GC screening.

Role of lncRNAs in the Development of an Aggressive Phenotype in Gallbladder Cancer

Long non-coding RNAs are sequences longer than 200 nucleotides that are involved in different normal and abnormal biological processes exerting their effect on proliferation and differentiation, among other cell features. Functionally, lncRNAs can regulate gene expression within the cells by acting at transcriptional, post-transcriptional, translational, or post-translational levels. However, in pathological conditions such as cancer, the expression of these molecules is deregulated, becoming elements that can help in the acquisition of tumoral characteristics in the cells that trigger carcinogenesis and cancer progression. Specifically, in gallbladder cancer (GBC), recent publications have shown that lncRNAs participate in the acquisition of an aggressive phenotype in cancer cells, allowing them to acquire increased malignant capacities such as chemotherapy resistance or metastasis, inducing a worse survival in these patients. Furthermore, lncRNAs are useful as prognostic and diagnostic biomarkers since they have been shown to be differentially expressed in tumor tissues and serum of individuals with GBC. Therefore, this review will address different lncRNAs that could be promoting malignant phenotypic characteristics in GBC cells and lncRNAs that may be useful as markers due to their capability to predict a poor prognosis in GBC patients.

Functional interplay between long non-coding RNAs and the Wnt signaling cascade in osteosarcoma

Osteosarcoma is a common and highly malignant bone tumor among children, adolescents and young adults. However, the underlying molecular mechanisms remain largely unexplored. LncRNAs are transcripts with no or limited protein-coding capacity in human genomes, and have been demonstrated to play crucial functions in initiation, progression, therapeutic resistance, recurrence and metastasis of tumor. Considerable studies revealed a dysregulated lncRNA expression pattern in osteosarcoma, which may act as oncogenes or suppressors to regulate osteosarcoma progression. Wnt signaling pathway is an important cascade in tumorigenesis by modulation of pleiotropic biological functions including cell proliferation, apoptosis, differentiation, stemness, genetic stability and chemoresistance. Hyperactivation or deficiency of key effectors in Wnt cascade is a common event in many osteosarcoma patients. Recently, increasing evidences have suggested that lncRNAs could interplay with component of Wnt pathway, and thereby contribute to osteosarcoma onset, progression and dissemination. In this review, we briefly summarize Wnt signaling-related lncRNAs in osteosarcoma progression, aiming to gain insights into their underlying crosstalk as well as clinical application in osteosarcoma therapeutic modalities.