RESUMO
BACKGROUND This study investigated the molecular mechanism of the effect of CD44 on the recurrence of EGC after ESD, including the potential regulator and signaling pathways of CD44. MATERIAL AND METHODS We searched the miRNA online database (www.mirdb.org) with the "seed sequence" located within the 3'-UTR of the target gene, and performed luciferase assay to test the miRNA/mRNA relationship. We also determined the expression of CD44 in the EGC and control samples. In addition, statistical analysis was used to explore the role of miR-328 as a biomarker to predict the recurrence after ECD. RESULTS We validated CD44 to be the direct gene via luciferase reporter assay system. We also established the negative regulatory relationship between miR-328 and CD44 via studying the relative luciferase activity at different concentrations of miR-328 mimics. We also conducted real-time PCR and Western blot analysis to study the mRNA and protein expression level of CD44 among different groups (recurrence-positive and recurrence-negative) or cells treated with different concentrations of miR-328 mimics/inhibitors, indicating the negative regulatory relationship between miR-328 and CD44. We also investigated the relative viability of EGC cells when transfected with miR-328 mimics (50 nM and 100 nM) and miR-328 inhibitors (100 nM) to validate miR-328 to be negatively interfering with the viability of EGC cells. miR-328 was also recognized as a potential biomarker to predict recurrence after ESD in EGC patients via analysis of the recurrence-free rate among different groups of EGC patients. CONCLUSIONS The expression level of miR-328 can function as a predictive biomarker of recurrence after ECD in patients with EGC via targeting CD44.
Assuntos
Biomarcadores Tumorais/biossíntese , Receptores de Hialuronatos/metabolismo , MicroRNAs/biossíntese , Recidiva Local de Neoplasia/genética , Neoplasias Gástricas/genética , Regiões 3' não Traduzidas , Adulto , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Ressecção Endoscópica de Mucosa/métodos , Endoscopia Gastrointestinal/métodos , Feminino , Gastroscopia/métodos , Humanos , Receptores de Hialuronatos/biossíntese , Receptores de Hialuronatos/genética , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Resultado do TratamentoRESUMO
Long noncoding RNAs (lncRNAs) are important regulators of the biological functions and underlying molecular mechanisms of colorectal cancer (CRC). However, the role of the lncRNA ZEB1-AS1 in CRC is not thoroughly understood. In this study, we found that ZEB1-AS1 was markedly upregulated in CRC. ZEB1-AS1 knockdown significantly suppressed CRC cell proliferation and induced apoptosis, whereas enhanced expression of ZEB1-AS1 had the opposite effect. Bioinformatics analysis identified miR-181a-5p as a candidate target of ZEB1-AS1. Moreover, we found an inverse correlation between ZEB1-AS1 and miR-181a-5p expression in CRC tissue. Inhibition of miR-181a-5p significantly upregulated ZEB1-AS1, whereas overexpression of miR-181a-5p had the opposite effect, suggesting that ZEB1-AS1 is negatively regulated by miR-181a-5p. Using luciferase reporter and RIP assays, we found that miR-181a-5p directly targets ZEB1-AS1. Importantly, ZEB1-AS1 may act as an endogenous 'sponge' to regulate miRNA targets by competing for miR-181a-5p binding. In summary, our findings provide the evidence supporting the role of ZEB1-AS1 as an oncogene in CRC. Our study also demonstrates that miR-181a-5p targets not only protein-coding genes but also the lncRNA ZEB1-AS1.