RESUMO
<p><b>BACKGROUND</b>The E-26 transformation-specific related gene (ERG) is frequently expressed in cytogenetically normal acute myeloid leukemia (CN-AML). Herein, we performed a meta-analysis to investigate the relationship between the prognostic significance of ERG expression and CN-AML.</p><p><b>METHODS</b>A systematic review of PubMed database and other search engines were used to identify the studies between January 2005 and November 2016. A total of 667 CN-AML patients were collected from seven published studies. Of the 667 patients underwent intensive chemotherapy, 429 had low expression of ERG and 238 had high expression of ERG. Summary odds ratio (OR) and the 95% confidence interval (CI) for the ERG expression and CN-AML were calculated using fixed- or random-effects models. Heterogeneity was assessed using Chi-squared-based Q- statistic test and I2 statistics. All statistical analyses were performed using R.3.3.1 software packages (R Foundation for Statistical Computing, Vienna, Austria) and RevMan5.3 (Cochrane Collaboration, Copenhagen, Denmark).</p><p><b>RESULTS</b>Overall, patients with high ERG expression had a worse relapse (OR = 2.5127, 95% CI: 1.5177-4.1601, P = 0.0003) and lower complete remission (OR = 0. 3495, 95% CI: 0.2418-0.5051, P< 0.0001). With regard to the known molecular markers, both internal tandem duplications of the fms-related tyrosine kinase 3 gene (OR = 3.8634, 95% CI: 1.8285-8.1626, P = 0.004) and brain and acute leukemia, cytoplasmic (OR = 3.1538, 95% CI: 2.0537-4.8432, P< 0.0001) were associated with the ERG expression. In addition, the results showed a statistical significance between French-American-British (FAB) classification subtype (minimally differentiated AML and AML without maturation, OR = 4.7902, 95% CI: 2.7772-8.2624, P< 0.0001; acute monocytic leukemia, OR = 0.2324, 95% CI: 0.0899-0.6006, P = 0.0026) and ERG expression.</p><p><b>CONCLUSION</b>High ERG expression might be used as a strong adverse prognostic factor in CN-AML.</p>
RESUMO
<p><b>OBJECTIVE</b>To establish and characterize imatinib-resistant gastrointestinal stromal tumor (GIST) xenografts. Further provided an ideal experimental platform through the imatinib-resistant GIST xenografts to investigate the mechanism of resistance to imatinib.</p><p><b>METHODS</b>Imatinib-resistant GIST cells were injected under the skin of athymic nude mice to establish animal models of human imatinib-resistant GIST. The molecular and histopathologic features of GIST xenografts were also analysed and compared with their counterpart of cell lines.</p><p><b>RESULTS</b>The xenograft tumor models had been established by subcutaneously injection of GIST cells into nude mice. Immunohistochemistry results showed CD117 expression was positive in GIST-PR2 xenograft tumor, but negative in GIST-R. In GIST-PR1, tumor areas showing rhabdomyoblastic differentiation were presented next to areas with classic GIST morphology. The rhabdomyoblastic component demonstrated consistently positivity for desmin and myogenin, whereas CD117 was completely negative. The mutation profiles of these xenograft tumors were the same as their counterpart of cell lines.</p><p><b>CONCLUSIONS</b>Human GIST xenografts with mutation in c-kit have been established from imatinib-resistant GIST lines. Those models will enable further studies on mechanisms of resistance, combination therapies and allow testing of novel targeted therapies.</p>