Clinical significance and function of RDH16 as a tumor-suppressing gene in hepatocellular carcinoma.

AIM: Our previous transcriptome sequencing analysis detected that retinol dehydrogenase 16 (RDH16) was dramatically downregulated in hepatocellular carcinoma (HCC). RDH16 belongs to the short-chain dehydrogenases/reductases super family, and its role in HCC remains unknown. This study aimed to investigate the expression and function of RDH16 in HCC. METHODS: The mRNA and protein level of RDH16 in HCC samples were detected by quantitative real-time polymerase chain reaction and immunohistochemistry analyses, respectively. The role of RDH16 in HCC was determined by in vitro and in vivo functional studies. RESULTS: Downregulation of RDH16 has been detected in approximately 90% of primary HCCs, which was significantly associated with high serum alpha-fetoprotein level, tumor size, microsatellite formation, thrombus, and poor overall survival of HCC patients. Compared with non-tumor tissues, higher density of methylation was identified in HCC samples. In addition, RDH16 increases the level of retinoic acid and blocks the de novo synthesis of fatty acid in HCC cells. Functional study shows that ectopic expression of RDH16 in HCC cells suppresses cell growth, clonogenicity, and cell motility. CONCLUSIONS: RDH16 might be a prognostic biomarker and intervention point for new therapeutic strategies in HCC.

Increased expression of EIF5A2, via hypoxia or gene amplification, contributes to metastasis and angiogenesis of esophageal squamous cell carcinoma.

BACKGROUND & AIMS: Solid tumors often become hypoxic, leading to activation of hypoxia-response genes. We investigated the effects of overexpression of the hypoxia response genes eIF5A2 in esophageal squamous cell carcinoma (ESCC). METHODS: We used quantitative real-time polymerase chain reaction and immunohistochemistry analyses to compare expression of eIF5A2 between paired ESCC samples and nontumor esophageal tissues, and fluorescence in situ hybridization to detect gene copy-number alterations. Luciferase reporter and chromatin immunoprecipitation assays were used to study interactions between eIF5A2 and hypoxia-inducible factor-1α (HIF1α). We determined the effects of eIF5A2 overexpression and knockdown in ESCC cell lines and growth of ESCC xenograft tumors in nude mice. RESULTS: Levels of eIF5A2 messenger RNA and protein were increased in >40% of ESCC samples compared with matched nontumor tissues, along with levels of HIF1α and vascular endothelial growth factor. Increased levels of EIF5A2 were significantly associated with ESCC metastasis to lymph nodes (P < .001) and tissue invasion (P = .037), and shorter survival times of patients (P < .001). Amplification of eIF5A2 was detected in 35.14% of ESCC samples that overexpressed eIF5A2. Hypoxia increased expression of eIF5A2 4- to 8-fold in ESCC cell lines; we observed bidirectional regulation between eIF5A2 and HIF1α. Transient transfection of ESCC cell lines with eIF5A2 increased their migratory and invasive abilities and markers of the epithelial to mesenchymal transition, and eIF5A2 knockdown or HIFα inhibition reduced these. In mice, xenograft tumors grown from ESCC cells that expressed eIF5A2 formed tumors more rapidly than cells that expressed only vector (controls); they also expressed higher levels of HIF1α and vascular endothelial growth factor, and formed more microvessels than controls. Knockdown of eIF5A2 in ESCC cells with interfering RNAs reduced their growth as xenograft tumors in mice, particularly when mice were given docetaxel or cisplatin. CONCLUSIONS: eIF5A2 is overexpressed by gene amplification or hypoxia in ESCCs, and associated with up-regulation of HIF1α, metastasis, and shorter survival times of patients. Increased expression of eIF5A2 increases metastasis and angiogenesis in ESCC via the HIF1α-mediated signaling pathway.

Gradually increased Golgi protein 73 expression in the progression of benign liver diseases to precancerous lesions and hepatocellular carcinoma correlates with prognosis of patients.

AIM: Serum Golgi protein 73 (sGP73) is a novel biomarker for hepatocellular carcinoma (HCC). However, there are few reports on the pattern of GP73 expression in the progression of benign liver diseases to precancerous lesions and HCC. This study aimed to investigate GP73 expression and its correlation with clinicopathological parameters. METHODS: Tissue GP73 (tGP73) levels were detected in specimens of group A (n = 186) including HCC, peritumoral tissue (PTL), high/low-grade hepatic atypical hyperplasia (AH), chronic hepatitis B (CHB) and normal controls (NC) by immunohistochemistry, and GP73 expression in group B (n = 159) and group C (n = 16) were detected by reverse transcription polymerase chain reaction and western blot, respectively. sGP73 levels were detected in subjects of group D (n = 287) by enzyme-linked immunoassay. RESULTS: GP73 expression increased gradually from NC, CHB, PTL to high-grade AH and HCC at both protein and mRNA levels (P < 0.05), while sGP73 in the HCC group was lower than in the liver cirrhosis (LC) group (P < 0.001). Both tGP73 and sGP73 levels were negatively associated with tumor size and tumor-node-metastasis stage, and tGP73 levels were positively associated with tumor differentiation. The high-tGP73 group showed significantly better overall and disease-free survival than the low-tGP73 group (P = 0.008, P = 0.018). Multivariate analysis revealed that the tGP73 level was an independent prognostic factor for HCC, but not sGP73. CONCLUSION: GP73 expression pattern suggests that the regulatory mechanism of GP73 is related to the progression of chronic liver diseases. Furthermore, a high level of tGP73 is a favorable prognostic factor for HCC.

Identification of small non-coding RNAs in the planarian Dugesia japonica via deep sequencing.

Freshwater planarian flatworm possesses an extraordinary ability to regenerate lost body parts after amputation; it is perfect organism model in regeneration and stem cell biology. Recently, small RNAs have been an increasing concern and studied in many aspects, including regeneration and stem cell biology, among others. In the current study, the large-scale cloning and sequencing of sRNAs from the intact and regenerative planarian Dugesia japonica are reported. Sequence analysis shows that sRNAs between 18nt and 40nt are mainly microRNAs and piRNAs. In addition, 209 conserved miRNAs and 12 novel miRNAs are identified. Especially, a better screening target method, negative-correlation relationship of miRNAs and mRNA, is adopted to improve target prediction accuracy. Similar to miRNAs, a diverse population of piRNAs and changes in the two samples are also listed. The present study is the first to report on the important role of sRNAs during planarian Dugesia japonica regeneration.

Association of TNF-α, IGF-1, and IGFBP-1 levels with the severity of osteopenia in mice with nonalcoholic fatty liver disease.

BACKGROUNDS: Nonalcoholic fatty liver disease (NAFLD) exhibits a close association with osteoporosis. This work aims to assess the potential effects of NAFLD on the progression of osteopenia in animal models. METHODS: Forty-eight C57BL/6 female mice were randomly divided to wild-type (WT) group and high-fat diet (HFD) group. The corresponding detections were performed after sacrifice at 16, 24 and 32 weeks, respectively. RESULTS: At 16 weeks, an remarkable increase in body weight and lipid aggregation in the hepatocytes of HFD group was observed compared to the WT group, while the bone structure parameters showed no significant difference. At 24 weeks, the levels of TNF-α and IL-6 in NAFLD mice were significantly increased, while the level of osteoprotegerin mRNA in bone tissue was decreased, and the level of receptor activator of nuclear factor Kappa-B ligand mRNA was increased. Meanwhile, the function of osteoclasts was increased, and the bone microstructure parameters showed significant changes. At 32 weeks, in the HFD mice, the mRNA levels of insulin-like growth factor-1 (IGF-1), runt-related transcription factor 2, and osterix mRNA were reduced, while the insulin-like growth factor binding protein-1 (IGFBP-1) level was increased. Simultaneously, the osteoblast function was decreased, and the differences of bone structure parameters were more significant, showing obvious osteoporosis. CONCLUSIONS: The bone loss in HFD mice is pronounced as NAFLD progresses, and the changes of the TNF-α, IL-6, IGF-1, and IGFBP-1 levels may play critical roles at the different stages of NAFLD in HFD.