Hsa_circ_0060927 participates in the regulation of Caudatin on colorectal cancer malignant progression by sponging miR-421/miR-195-5p

Advanced strategies of targeting circular RNAs as therapeutic approaches in colorectal cancer drug resistance

Colorectal cancer (CRC) stands second in terms of mortality and third among the highest prevalent kinds of cancer globally. CRC prevalence is rising in moderately and poorly developed regions and is greater in economically advanced regions. Despite breakthroughs in targeted therapy, resistance to chemotherapeutics remains a significant challenge in the long-term management of CRC. Circular RNAs (circRNAs) have been involved in growing cancer therapy resistance, particularly in CRC, according to an increasing number of studies in recent years. CircRNAs are one of the novel subclasses of non-coding RNAs, previously thought of as viroid. According to studies, circRNAs have been recommended as biological markers for therapeutic targets and diagnostic and prognostic purposes. That is particularly notable given that the expression of circRNAs has been linked to the hallmarks of CRC since they are responsible for drug resistance in CRC patients; thereby, circRNAs are significant for chemotherapy failure. Moreover, knowledge concerning circRNAs remains relatively unclear despite using all these advanced techniques. Here, in this study, we will go over the most recent published work to highlight the critical roles of circRNAs in CRC development and drug resistance and highlight the main strategies to overcome drug resistance to improve clinical outcomes.

The Role of the Dysregulation of Long Non-Coding and Circular RNA Expression in Medulloblastoma: A Systematic Review

Medulloblastoma (MB) is the most common malignant brain tumor in childhood. Although recent multi-omic studies have led to advances in MB classification, there is still room for improvement with regard to treatment response and survival. Therefore, identification of new and less invasive biomarkers is needed to refine the diagnostic process and to develop more personalized treatment strategies. In this context, non-coding RNAs (ncRNAs) could be useful biomarkers for MB. In this article, we reviewed the role of two types of ncRNAs, long non-coding (lncRNAs) and circular RNAs (circRNAs), as biomarkers for the diagnosis, subgroup classification, and prognosis of MB. We also reviewed potential candidates with specific functions and mechanisms of action in the disease. We performed a search in PubMed and Scopus using the terms ("long non coding RNAs" OR "lncRNAs") and ("circular RNAs" OR "circRNAs") AND "medulloblastoma" to identify biomarker discovery or functional studies evaluating the effects of these ncRNAs in MB. A total of 26 articles met the inclusion criteria. Among the lncRNAs, the tumorigenic effects of the upregulated lnc-IRX3-80 and lnc-LRRC47-78 were the most studied in MB. Among the circRNAs, the upregulation of circSKA3 and its functional impact in MB cell lines were the most consistent results, so this circRNA could be considered a potential biomarker in MB. Additional validation is required for many deregulated lncRNAs and circRNAs; therefore, further studies are warranted.

An epigenetic modulator with promising therapeutic impacts against gastrointestinal cancers: A mechanistic review on microRNA-195

Due to their high prevalence, gastrointestinal cancers are one of the key causes of cancer-related death globally. The development of drug-resistant cancer cell populations is a major factor in the high mortality rate, and it affects about half of all cancer patients. Because of advances in our understanding of cancer molecular biology, non-coding RNAs (ncRNAs) have emerged as critical factors in the initiation and development of gastrointestinal cancers. Gene expression can be controlled in several ways by ncRNAs, including through epigenetic changes, interactions between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) and proteins, and the function of lncRNAs as miRNA precursors or pseudogenes. As lncRNAs may be detected in the blood, circulating ncRNAs have emerged as a promising new class of non-invasive cancer biomarkers for use in the detection, staging, and prognosis of gastrointestinal cancers, as well as in the prediction of therapy efficacy. In this review, we assessed the role lncRNAs play in the progression, and maintenance of colorectal cancer, and how they might be used as therapeutic targets in the future.

Biological functions, mechanisms, and clinical significance of circular RNA in colorectal cancer

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide due to the lack of effective diagnosis and prognosis biomarkers and therapeutic targets, resulting in poor patient survival rates. Circular RNA (circRNA) is a type of endogenous non-coding RNA (ncRNA) with a closed-loop structure that plays a crucial role in physiological processes and pathological diseases. Recent studies indicate that circRNAs are involved in the diagnosis, prognosis, drug resistance, and development of tumors, particularly in CRC. Therefore, circRNA could be a potential new target for improving CRC diagnosis, prognosis, and treatment. This review focuses on the origin and biological functions of circRNA, summarizes recent research on circRNA's role in CRC, and discusses the potential use of circRNAs as clinical biomarkers for cancer diagnosis and prognosis, as well as therapeutic targets for CRC treatment.

Overexpression of hsa_circ_0061817 Can Inhibit the Proliferation and Invasion of Lung Cancer Cells Based on Active Compounds

Objective

This study was aimed at investigating the expression level of hsa_circ_0061817 in lung adenocarcinoma cells and its effect on cell proliferation and invasion and the possible mechanism of hsa_circ_0061817 in lung adenocarcinoma.

Methods

The overexpression plasmids of hsa_circ_0061817 (OE-hsacirc_0061817) were transfected into human lung A549 cells and mouse LLC-LUC cells, respectively. The cell viability was detected by CCK-8, and the cell proliferation was detected by cell clone formation assay and EdU assay. Transwell test was used to detect the ability of cell invasion, and apoptosis was detected by flow cytometry. WB was applied to determine the expression of apoptosis and epithelial mesenchymal transition- (EMT-) related proteins and also target proteins for observation the effect of OE-hsa_circ_0061817 on the growth of A549 cells in nude mice. Bioinformatics method was used to predict the binding microRNA (miRNA) of hsa_circ_0061817 and construct the regulatory network of competitive endogenous RNA (ceRNA) and functional analysis of miRNA target genes.

Results

Compared with PLO-ciR group, the cell viability, proliferation, and invasive ability of A549 and LLC-LUC were significantly reduced in OE-hsa_circ_00061817 group, while the apoptosis increased in OE-hsa_circ_00061817 group compared to PLO-ciR group. WB results showed that the expression of caspase 3, caspase 7, caspase 9, and E-cadherin increased significantly, while the expression levels of vimentin and N-cadherin decreased severely. Most importantly, OE-hsa_circ_00061817 inhibited the growth of A549 tumor-bearing nude mice. According to TargetScan and mirBase databases, hsa_circ_0061817 may competitively bind hsa_mir-181b-3p, hsa-mir-337-3p, hsa-mir-421, and hsa-mir-548d-3p. The results of functional enrichment showed that miRNA target genes were involved in many cancer-related biological processes, including negative regulation of apoptosis, gene expression, transcriptional imbalance in cancer, transforming growth factor-β, and P53 signal pathway.

Conclusions

Over expression of hsa_circ_0061817 inhibits the proliferation of lung adenocarcinoma A549 and LLC-LUC cells and may reduce the invasive ability of lung adenocarcinoma cells by weakening the process of EMT, which provides a new target for the prevention and treatment of lung adenocarcinoma.

The tumor suppressor function of hsa_circ_0006282 in gastric cancer through PTEN/AKT pathway

BACKGROUND

Circular RNAs (circRNAs) play key roles in carcinogenesis. However, the roles of circRNAs in gastric cancer are largely unknown. The aim of this study is to study the possible roles of hsa_circ_0006282 in gastric cancer.

METHODS

The hsa_circ_0006282 levels in gastric cancer cell lines, 85 gastritis tissues, and 103 paired gastric cancer tissues and non-tumor tissues were first detected by quantitative real-time reverse transcription-polymerase chain reaction. RNA interference and hsa_circ_0006282 expression plasmid were further used to manipulate hsa_circ_0006282 expression in gastric cancer. Finally, biological effects of hsa_circ_0006282 were analyzed by real-time cell analysis, flow cytometry, Transwell, cell cloning assay and Western blot analysis.

RESULTS

Hsa_circ_0006282 was down expressed in gastric cancer cells, gastritis tissues, and gastric cancer tissues. The abilities of cell proliferation, cell migration and resistance to apoptosis were enhanced after hsa_circ_0006282 was downregulated, while overexpression of hsa_circ_0006282 got opposite results. Besides, Western blot showed that the levels of protein kinase B (AKT) and cyclin-dependent kinase 2 (CDK2) were significantly increased and decreased after knockdown and up-regulation of hsa_circ_0006282, respectively, while phosphatase and tensin homolog deleted on chromosome ten (PTEN) was significantly opposite regulated. Finally, hsa_circ_0006282 promoted the expression of PTEN by sponging hsa-miR-136-5p.

CONCLUSION

By regulating the PTEN/AKT signaling pathway through competitively binding with hsa-miR-136-5p, hsa_circ_0006282 suppresses the growth of gastric cancer.