Advances in research on oncolytic adenoviruses in tumor therapy / 病毒学报

Oncolytic adenoviruses (Ads), which are live, replication-competent viruses that can selectively replicate in tumor cells and lead to cell lysis, have been used in tumor therapy. But due to the complexity and high mutability of human tumors, it becomes a major strategy to improve the selectivity, efficacy, and safety of oncolytic Ads. The oncolytic Ads that can express short hairpin RNA, cytokines, suicide gene, and matrix-modulating proteins have higher antitumor activity than the wild type. Tumor-specific promoters, especially hTERT and HRE promoters, increase the selectivity of oncolytic Ads for tumor cells. Moreover, oncolytic Ads surface-modified by polyethylene glycol (PEG), liposomes, biodegradable nanoparticles, and polypeptides have reduced immunogenicity and hepatotoxicity and improved antitumor activity when systemically administered, and the selectivity of oncolytic Ads can be significantly increased when linking PEG to antibodies, small peptides, cytokines, and ligands. Therefore, engineered oncolytic Ads combining the advantages of viral and non-viral vectors, as well as immunotherapy, are a promising strategy for improving the efficacy of targeted virotherapy.

Differentiation of rat bone marrow mesenchymal stem cells into adipocytes and blockage of the differentiation / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the pathogenesis of tumors by blocking the normal differentiation process of stem cells.</p><p><b>METHODS</b>Bone marrow mesenchymal stem cells (BMSCs) from rats were isolated, cultured and purified by whole bone marrow adherence method. The rat BMSCs were induced to differentiate into adipocytes with dexamethasone, insulin and indomethacin. Blockage of the differentiation process was induced by 3-methylcholanthrene (3-MC).</p><p><b>RESULTS</b>The differentiation experiment showed that at 30 days after the induction, oil red O staining-positive cells occurred with increased intracytolasmic lipid droplets, characteristic for adipocytes. The differentiation blockage experiment showed that at 30 days after induction, the deposits of oil red O staining-cytoplasmic lipid droplets was significantly reduced, indicating that the blocked cells were adipocytes, but not fully differentiated. Morphological identification showed that cell contact inhibition disappeared, abnormal cell nuclei, increased number of micronucleus aberration and karyotype abnormalities, indicating that malignant transformation of the stem cells occurred after the differentiation blockage.</p><p><b>CONCLUSIONS</b>The results of this study show a blockage of the differentiation of that stem cells at the intermediate phase, and a tendency of malignant transformation of the stem cells. The results of our study provide new evidence that cancer stem cells may be originated by suppression of stem cell differentiation.</p>

Cyclin D1 gene G870A polymorphism and susceptibility to nasopharyngeal carcinoma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>The aim of this study was to investigate the susceptibility and prognostic implications of the cyclin D1 gene (CCND1) G870A polymorphism to nasopharyngeal carcinomas (NPC) in Han population in Yunnan China.</p><p><b>METHODS</b>Two hundred and forty one cases with NPC and 271 matched cancer-free controls were genotyped for the CCND1 G870A polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing. The adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated by using unconditional logistic regression model. Overall survival was assessed using univariate and multivariate analyses.</p><p><b>RESULTS</b>Contrast with homozygous CCND1 G870G, A allele significantly increasing risk of NPC was associated with homozygous A870A (OR = 4.79, 95% CI 2.77 - 8.28, P < 0.001) and heterozygous A870G (OR = 1.72, 95% CI 1.10 - 2.68, P = 0.017). The subjects at least having one CCND1 870A allele had OR of 2.40 (95% CI 1.59 - 3.63, P < 0.001). Furthermore, smoking may increase the risk of developing NPC interacting with CCND1 G870A polymorphism. Kaplan-Meier analysis and Cox regression analysis demonstrated that the five-year survival rate of subjects with AA, AG and GG genotype was 56.2%, 78.5% and 81.4% (AA vs GG, P = 0.003; AA vs AG, P = 0.012; AG vs GG, P = 0.132), but not independent prognostic factor in NPC (P = 0.501).</p><p><b>CONCLUSIONS</b>The CCND1 870A allele is associated with the NPC in Han population in Yunnan China, meanwhile, showed a significant prognosis for those patients.</p>