BACKGROUND: Individual three-dimensional (3D) scaffolds can be constructed by 3D printing via Computer Aided Design based on the given anatomical measurements of related tissues. A rapid and accurate reconstruction of bone, cartilage, muscle and vessel also can be achieved by 3D printing; however, many problems still remain unsolved.OBJECTIVE: To summarize the principle and classification of 3D printing, the classification, characteristics and histocompatibility of scaffolds through reviewing the articles addressing 3D printing applied in bone tissue engineering,thereby providing theoretical foundation for the study on the construction of tissue-engineered bone.METHODS: PubMed and CNKI databases were retrieved for the literatures regarding the application of 3D printing technology in bone tissue engineering published from January 2001 to January 2017 using the keywords of three-dimensional printing, rapid prototyping manufacturing, bone tissue engineering in English and Chinese,respectively. Finally, 30 articles were reviewed and discussed in accordance with the inclusion and exclusion criteria.RESULTS AND CONCLUSION: The microstructures of normal tissues can be reconstructed and seed cells are printed on the 3D scaffolds synchronously by 3D printing technology. Moreover, the scaffold degradation and cell differentiation are synchronous, which contributes to tissue repair. Biological ceramics have been widely used in bone tissue engineering because of its good biocompatibility and mechanical properties. However, the urgent problems such as angiogenesis and cellular signal transduction still need to be addressed.

Objective To investigate the expression of c-Myc in gastric mucosa associated lymphoid tissue (MALT) lymphoma and its implications on prognosis.Methods The clinical data of 79 patients hospitalized in our hospital from 2009 to 2015 were retrospectively analyzed.In these patients,38 patients were low-grade MALT lymphoma,20 patients were high-grade MALT lymphoma,21 patients were diffused large B cell lymphoma (DLBCL).Real-time PCR was used to detect the levels of c-Myc expression in gastric MALT tissues and pair-matched adjacent normal tissues.The relationship between the expression of c-Myc and prognosis of patients was evaluated combing with the clinical data.Results Compared with the normal tissues,the expression levels of c-Myc protein were 15.7％ (6/38),25％ (5/20) and 28.5％ (6/21)in patients with low-grade MALT lymphoma,high-grade MALT lymphoma,and DLBCL.The relative expression levels of cMyc mRNA were gradually elevated in low-grade MALT lymphoma,high-grade MALT lymphoma and DLBCL.The tumor size and depth of invasion can influence the expression level of c-Myc.Survival analysis found that the overall survival rates and relapse-free survival rates were lower in patients with c-Myc positive expression than those of patients with negative expression (P ＜ 0.05).Conclusion C-Myc plays a key role in the malignant transformation of gastric MALT lymphoma.

Objective To investigate the application value of the human B cell-confinement receptor P2RY8 in the diagnosis and prognosis of hepatocellular carcinoma (HCC) and its association with tumor immunity. Methods The Cancer Genome Atlas database was used to compare the expression of P2RY8. R software package was used to analyze the correlation between P2RY8 and tumor staging, and the receiver operating characteristic (ROC) curve and a nomogram model were established for diagnosis and survival. Tumor Immune Evaluation Resource was used to analyze immune cell infiltration, immune cell biomarkers, and immune checkpoints. STRING database was used to analyze protein-protein interaction network information. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to analyze the function of P2RY8 and its interacting genes. For the purpose of validation, HCC tissue samples were collected from 64 patients who underwent radical surgery for HCC from June 2007 to November 2008, and the corresponding adjacent tissue samples were collected from 35 patients out of these patients (tissue chips were purchased from Shanghai Outdo Biotech Co., Ltd.); related clinical data and follow-up data were analyzed, and immunohistochemistry was used to measure the expression of P2RY8 in HCC and adjacent tissue samples. The t -test was used for comparison of normally distributed continuous data between two groups; the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups, and the Kruskal-Wallis H test was used for comparison between multiple groups. The chi-square test was used for comparison of categorical data between two groups. A Spearman correlation analysis was used to investigate the correlation between two variables. The Kaplan-Meier method was used to plot survival curves, and the log-rank test was used to calculate survival rates. Results P2RY8 was overexpressed in HCC, and the expression level of P2RY8 could accurately differentiate tumor from normal tissue, with an area under the ROC curve of 0.794. The patients with a higher expression level of P2RY8 tended to have a better prognosis ( P =0.005). The data from 64 clinical samples also confirmed that compared with the patients with a low expression level of P2RY8, the patients with a high expression level of P2RY8 had significantly higher 3-year survival rate (78.9% vs 46.2%, P =0.007), 5-year survival rate (76.3% vs 38.5%, P =0.002), and overall survival time [92.5 (48.8-102.0) months vs 33.0 (25.0-95.5) months, P =0.022], and the Kaplan-Meier survival curve further indicated that the expression level of P2RY8 was associated with the prognosis of HCC patients. In addition, P2RY8 was positively correlated with immune cell infiltration and immune checkpoint in HCC. The GO/KEGG pathway enrichment analyses showed that P2RY8 was enriched in the signal transduction pathways such as humoral immunity and cellular immunity. Conclusion P2RY8 participates in the development, progression, and immune regulation of HCC, and therefore, P2RY8 can serves as a potential biomarker and a therapeutic target for the diagnosis and prognosis of HCC.