High‐mobility group AT‐hook 2 promotes growth and metastasis and is regulated by miR‐204‐5p in oesophageal squamous cell carcinoma

Abstract

Background: To investigate the expression of high-mobility group AT-hook 2 (HMGA2) and miR-204-5p in oesophageal squamous cell carcinoma (ESCC) and their biological roles in ESCC development and progression. Methods: HMGA2 and miR-204-5p expression levels in ESCC tissues and cell lines were detected by qRT-PCR, Western blotting and immunohistochemical staining.ESCC cell lines were transfected with a small interfering RNA for HMGA2 and miR-204-5p mimic to downregulate and upregulate the expression levels of HMGA2 and miR-204-5p, respectively. The growth, migration and invasion abilities of ESCC cells were assessed by MTT, colony formation, wound-healing and Transwell assays, respectively. A luciferase reporter gene assay was used to determine whether the 3′-untranslated coding regions of HMGA2 could be directly bound by miR-204-5p. Results: HMGA2 expression was markedly upregulated (P < .001), while miR-204-5p expression was markedly downregulated (P = .003) in ESCC tissues compared with adjacent normal tissues. HMGA2 expression was correlated with tumour size, invasion depth, lymph node metastasis and tumour-node-metastasis stage (all P < .05) and was identified as an independent prognostic factor for ESCC patients. The expression levels of HMGA2 and miR-204-5p were negatively correlated (r 2 = 0.609, P < .001). HMGA2 knockdown or miR-204-5p overexpression markedly inhibited ESCC cell growth, migration and invasion (P < .05). In addition, restoration of HMGA2 expression partly reversed the inhibitory effects of miR-204-5p overexpression on migration and invasion (P < .05). The luciferase reporter gene assay suggested that HMGA2 is a direct downstream target of miR-204-5p. Conclusion: HMGA2 functions as an oncogene in the growth and metastasis of ESCC and is negatively regulated by miR-204-5p.

CXCR4 promotes the growth and metastasis of esophageal squamous cell carcinoma as a critical downstream mediator of HIF‐1α

“…The clinical features of the patients are listed in Table 1. IHC analyses of the specimens were performed with anti‐HIF‐1α and anti‐CXCR4 antibodies as described previously 21 . Survival time was defined from the date of surgery to the date of death or the last follow‐up.…”

“…Proteins from tissues or cells were extracted with protein lysate containing protease inhibitors. Western blotting was performed as previously described 21 . The protein bands were detected by enhanced chemiluminescence.…”

“…IHC analyses of the specimens were performed with anti-HIF-1α and anti-CXCR4 antibodies as described previously. 21 Survival time was defined from the date of surgery to the date of death or the last follow-up. All operations for human subjects were approved by the Research Ethics Committee of our hospital, and informed consent forms were signed and provided by all patients.…”

“…Western blotting was performed as previously described. 21 The protein bands were detected by enhanced chemiluminescence. Table S3 lists all antibodies used in this study.…”

MicroRNAs and Stem-like Properties: The Complex Regulation Underlying Stemness Maintenance and Cancer Development

“…Indeed, Lin28a binds highly conserved elements located in Hmga2 mRNA to properly control Hmga2 accumulation during differentiation [42]. HMGA2 expression is undetectable in adult tissues, and it is significantly overexpressed in different cancers as hepatocellular carcinomas, esophageal squamous cell carcinoma, tongue squamous cell carcinoma, and thyroid carcinoma [192][193][194][195][196]. It represents another ESC-specific factor that can induce tumorigenesis using multiple mechanisms.…”