Prognostic value of long non-coding RNA HOST2 expression and its tumor-promotive function in human osteosarcoma.

OBJECTIVE: Aberrant expression of long noncoding RNA (lncRNA) is associated with carcinogenesis of various tumors. The aim of current study was to explore the clinical significance and biological function of long non-coding RNA HOST2 (lnc-HOST2) in patients with osteosarcoma.

PATIENTS AND METHODS: The expression of lnc-HOST2 was detected by quantitative Real-time PCR (qRT-PCR) in 163 osteosarcoma specimens and matched the normal tissues. The significance of lnc-HOST2 as a prognostic factor as well as its relationship with survival was determined. The effects of lnc-HOST2 expression on the biological behavior of osteosarcoma cells were investigated by MTT and flow cytometry. qRT-PCR and Western blot were used to evaluate the mRNA and protein expression of apoptosis-related factors.

RESULTS: The expression levels of lnc-HOST2 in osteosarcoma tissues were significantly higher than those in corresponding noncancerous bone tissues (p < 0.01). Statistical assay indicated that the expression level of lnc-HOST2 was positively correlated with tumor stage (p = 0.003) and distant metastasis (p = 0.000). Furthermore, Kaplan-Meier analysis suggested that patients with high lnc-HOST2 showed poorer overall survival than those with low lnc-HOST2 (p = 0.000). The univariate and multivariate analysis further revealed that lnc-HOST2 expression was an independent prognostic factor for overall survival. Then, functionally, down-regulation of lnc-HOST2 suppressed proliferation and induced cell apoptosis in osteosarcoma cells. Notably, we confirmed that up-regulation of lnc-HOST2 led to Bcl-2 downregulation and Bax upregulation in osteosarcoma cells.

CONCLUSIONS: We provided the first evidence that lnc-HOST2 may serve as a novel prognostic marker in osteosarcoma. Further, targeting lnc-HOST2 may represent an attractive target therapy for osteosarcoma.