SNHG14 stimulates cell autophagy to facilitate cisplatin resistance of colorectal cancer by regulating miR-186/ATG14 axis

Colorectal cancer (CRC) is a malignant tumor with a high incidence and death rate in the world. Molecular interactions inside cells or tissues during tumor occurrence, development, and drug resistance are important for disease prevention and treatment. The long non-coding RNA SNHG14 has been proven to exert its oncogenic function in multiple cancers. However, there is no study regarding the role of SNHG14 in CRC research. In the present study, we applied RT-qPCR and western blot to determine the gene expression levels. MTT and TUNEL assays were used to detect cell proliferation and apoptosis rate. Cell migration and invasion abilities were determined by wound healing and transwell assays, respectively. StarBase was used to predict the potential binding sites and luciferase reporter assay was applied to confirm the direct interactions. Besides, we conducted a xenograft experiment to detect tumor growth rate in vivo. Our results showed that SNHG14 and ATG14 were both significantly higher in CRC tumor tissues than the normal ones, while miR-186 was decreased. The similar results were also observed in CRC cell lines. We confirmed that SNHG14 could directly interact with miR-186 and inhibited its expression. Meanwhile, miR-186 could directly bind ATG14 to inhibit its expression level. In vitro experiments showed that higher expression of SNHG14 led to higher cell proliferation, migration and invasion, while miR-186 significantly inhibited these tumor phenotypes. Furthermore, overexpression of ATG14 could strongly recover the CRC phenotypes attenuated by shSNHG14 or miR-186 mimics. Interestingly, we constructed cisplatin-resistant CRC cells and found that overexpression of ATG14 significantly enhanced the cell proliferation rate and inhibited cell apoptosis. Our research indicated that the novel axis of SNHG14/miR-186/ATG14 could play a vital role in regulating CRC cell progression. Moreover, this axis showed its clinical potential in regulating cisplatin resistance during CRC treatment.