Long noncoding RNA HOXD-AS1 in various cancers: a meta-analysis and TCGA data review

Background and aims: HOXD antisense growth-associated long noncoding RNA (HOXD-AS1) was reported to be upregulated in various cancers, such as gastric cancer, hepatocellular carcinoma, colorectal cancer, and glioma. Here, we conducted a meta-analysis and The Cancer Genome Atlas data review to investigate the clinicopathologic and prognostic value of HOXD-AS1 in patients with malignant tumors. Materials and methods: Systematic literatures were searched from PubMed, Medline, Cochrane Library, Web of Science, EMBASE database, Ovid, Chinese CNKI, and the Chinese WanFang database. The role of HOXD-AS1 in cancers was evaluated by pooled ORs and HRs with 95% CIs. The Cancer Genome Atlas dataset was used to explore the prognostic value of HOXD-AS1 in various cancers. RESULTS: Fifteen studies with 1,678 patients were included in this meta-analysis. The results indicated that HOXD-AS1 was associated with tumor size, differentiation, lymph node metastasis, and TNM stage. Moreover, the high HOXD-AS1 expression indicated a poor overall survival (OS) rate and can be an independent predictive factor for OS. The TCGA dataset, which included 9,502 cancer patients, showed that the expression of HOXD-AS1 was related to poor OS and disease-free survival. We also analyzed the prognostic role in different kinds of cancers such as digestive cancers, female reproductive system cancers, respiratory system cancers, and urinary system cancers. CONCLUSION: This study demonstrated that HOXD-AS1 was closely correlated with tumor size, lymph node metastasis, distant metastasis, and TNM stage, and an increased HOXD-AS1 expression could be a reliable prognostic biomarker in human cancers. However, more studies are needed to confirm this conclusion.