Hsa_circ_0079557 Promotes the Proliferation of Colorectal Cancer Cells Through the hsa_circ_0079557/miR-502-5p/CCND1 Axis.

BACKGROUND/AIM: Recent studies have demonstrated the crucial regulatory roles of circular RNAs (circRNAs) in cancer initiation and progression. The sponge mechanism of circRNAs has been shown to be widely active in various types of tumors. However, many circRNAs still have not been verified to function through this mechanism. This study aimed to investigate the regulatory mechanism of hsa_circ_0079557 in colorectal cancer (CRC) and its role in CRC progression. MATERIALS AND METHODS: Raw gene expression profile datasets were downloaded from Gene Expression Omnibus (GEO) and combined to form a new dataset. Hsa_circ_0079557 was found to be highly expressed in CRC. Its role was evaluated in vitro and in vivo through a series of experiments, including quantitative real-time polymerase chain reaction (qRT-PCR), flow cytometry, colony formation, cell counting kit-8 (CCK-8), transwell assays, scratch wound healing assays, nude mice experiments, and immunohistochemistry (IHC). The association between hsa_circ_0079557 and the identified target microRNAs (miRNA) was confirmed through fluorescence in situ hybridization (FISH) and dual-luciferase reporter assays. The downstream target proteins were predicted using the web-based tool "TargetScan," and their expressions were determined using Western blot (WB). RESULTS: Hsa_circ_0079557 was found to be relatively up-regulated in CRC tissues and cell lines. Suppression of hsa_circ_0079557 expression inhibited cell proliferation in vitro and in vivo. Additionally, hsa_circ_0079557 acted as a "molecular sponge" for miR-502-5p, up-regulating the expression of Cyclin D1 (CCND1). CONCLUSION: In this study, we identify a highly expressed circRNA in CRC and propose a novel pathway of hsa_circ_0079557/miR-502-5p/CCND1 in CRC.

Experiment Study on Damage Properties and Acoustic Emission Characteristics of Layered Shale under Uniaxial Compression.

The gently tilt-layered shale displays anisotropic behavior and includes structural planes that cause the rock to exhibit weakened features. As a result, the load-bearing capacity and failure mechanisms of this type of rock differ significantly from those of other rock types. A series of uniaxial compression tests were performed on shale samples from the Chaoyang Tunnel to investigate damage evolution patterns and typical failure characteristics of gently tilt-layered shale. An acoustic emission testing system was incorporated to analyze the acoustic emission parameters of the shale samples during the loading process. The results indicate that the failure modes of the gently tilt-layered shale are significantly correlated with the structural plane angles and water content. The shale samples gradually transition from tension failure to tension-shear compound failure as the structural plane angles and water content increase, with an increasing level of damage. The maximum values of AE ringing counts and AE energy for shale samples with diverse structural plane angles and water content are reached near the peak stress and serve as precursors to rock failure. The primary factor influencing the failure modes of the rock samples is the structural plane angle. The precise correspondence between the structural plane angle, water content, crack propagation patterns, and failure modes of gently tilted layered shale can be captured by the distribution of the RA-AF values.