Long non-coding RNA HOXD-AS1 promotes tumor progression and predicts poor prognosis in colorectal cancer

: Mounting evidence has indicated that long non‑coding RNAs (lncRNA) serve important roles in tumor development. Previous studies have demonstrated that the lncRNA HOXD cluster antisense RNA 1 (HOXD‑AS1) promotes tumor progression in numerous types of cancer; however, the role of HOXD‑AS1 in colorectal cancer (CRC) remains unclear. In the present study, the expression levels of HOXD‑AS1 were detected in CRC tissues and cell lines using quantitative polymerase chain reaction. In addition, the biological effects of HOXD‑AS1 on CRC were evaluated in vitro by cell counting kit‑8, colony formation and Transwell assays, and in vivo by tumorigenesis and metastasis assays. The results demonstrated that HOXD‑AS1 was upregulated in CRC tissues and cell lines, and that overexpression of HOXD‑AS1 was associated with poor prognosis in patients with CRC. Furthermore, knockdown of HOXD‑AS1 inhibited cell proliferation, cell invasion, epithelial‑mesenchymal transition and stem cell formation in vitro, as well as tumor growth and metastasis in vivo. Mechanistically, HOXD‑AS1 functioned as a competing endogenous RNA for miR‑217. In conclusion, the present study demonstrated that HOXD‑AS1 may promote CRC progression and metastasis by competing for miR‑217. In addition, HOXD‑AS1 may be considered an indicator of prognosis in patients with CRC.