ABSTRACT
Recently, an increasing number of studies have reported that dysregulation of circular RNA (circRNA) expression plays critical roles in the progression of several cancers, including colorectal cancer (CRC). However, the detailed molecular mechanisms of circRNAs involvement in CRC remain largely unknown. Here, we confirmed that the level of circEGFR was significantly increased in CRC tissues compared to matched adjacent non-tumor tissues, and a high level of circEGFR was correlated with poor clinicopathological characteristics and poor prognosis in patients with CRC. Moreover, increased circEGFR expression promoted CRC cell proliferation, migration, and invasion in vitro. Mechanistically, circEGFR acted as a ceRNA for miR-106a-5p to relieve the repressive effect of miR-106a-5p on DDX5 mRNA. Moreover, circEGFR enhanced DDX5 expression, thereby upregulating p-AKT levels. Together, these findings showed that circEGFR promoted CRC cell proliferation, migration, and invasion through the miR-106a-5p/DDX5/AKT axis, and may serve as a promising diagnostic marker and therapeutic target for CRC patients.
Subject(s)
Humans , Colorectal Neoplasms/genetics , MicroRNAs/genetics , Gene Expression Regulation, Neoplastic , Cell Movement/genetics , Cell Line, Tumor , Cell Proliferation/genetics , DEAD-box RNA Helicases , RNA, CircularABSTRACT
Osteoarthritis (OA), a type of joint diseases, could result in breakdown of joint cartilage and underlying bone. Accumulating evidences suggested that long non-coding RNAs play important roles in OA progression. However, the underlyingmechanism of H19 in OA is still not fully explored. The expression levels of H19 and miR-106a-5p in OA samples frompatients or cultured chondrocytes were examined by quantitative real time polymerase chain reaction. Cell proliferation andapoptosis were analysed by MTT assay and flow cytometry, respectively. Western blotting was employed to detect theexpression levels of PCNA, CyclinD1, Caspase 3 and Cleaved Caspase 3. StarBase database, luciferase assay and RNAimmunoprecipitation were introduced to confirm the relationship between H19 and miR-106a-5p. The correlation of H19and miR-106a-5p was analysed by Spearman rank analysis. H19 expression was upregulated, while miR-106a-5p level wasdownregulated in OA samples and IL-1b-treated chondrocytes. H19 overexpression inhibited the proliferation and inducedapoptosis in IL-1b-treated chondrocytes, while H19 knockdown induced the opposite effect. Luciferase and RIP assaydemonstrated that miR-106a-5p was a direct target of H19. miR-106a-5p overexpression led to proliferation promotion andapoptosis inhibition in chondrocytes treated by IL-1b and it reversed the effect of H19 addition. We conclude that H19could regulate proliferation and apoptosis of chondrocytes treated by IL-1b in OA via sponging miR-106a-5p