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Osteosarcoma typically arises in tissues of mesenchymal origin, and is the most malignant bone tumor characterized by high local aggressiveness, with poor therapeutic outcome. Busulfan has been widely used to treat CML. So far, there are no reports on the therapeutic effect of busulfan on osteosarcoma. Here, we showed that busulfan dose-dependently reduced the cell viability and proliferation, and induced cell apoptosis, senescence, and reactive oxygen species levels in two osteosarcoma cell lines. Moreover, a series of loss-of-function and gain-of-function experiments further indicated that busulfan may have its anti-osteosarcoma effect by upregulating the microRNA-200 (miR-200) family which subsequently downregulated its target genes ZEB1 and ZEB2. Furthermore, treatment with busulfan potentially inhibited the growth of implanted osteosarcoma in nude mice. Taken together, our data suggest that busulfan may have an anti-osteosarcoma effect through downregulating ZEB1 and ZEB2 through activating the miR-200 family, highlighting a possibility of using busulfan as a novel therapy for osteosarcoma.

BackgroundChinese medical universities typically have a high number of students, a shortage of teachers and limited equipment, and as such histology courses have been taught using traditional lecture-based formats, with textbooks and conventional microscopy. This method, however, has reduced creativity and problem-solving skills training in the curriculum. The virtual microscope (VM) system has been shown to be an effective and efficient educational strategy. The present study aims to describe a VM system for undergraduates and to evaluate the effects of promoting active learning and problem-solving skills.MethodsTwo hundred and twenty-nine second-year undergraduate students in the Third Military Medical University were divided into two groups. The VM group contained 115 students and was taught using the VM system. The light microscope (LM) group consisted of 114 students and was taught using the LM system. Post-teaching performances were assessed by multiple-choice questions, short essay questions, case analysis questions and the identification of structure of tissue. Students’ teaching preferences and satisfaction were assessed using questionnaires.ResultsTest scores in the VM group showed a significant improvement compared with those in the LM group (p < 0.05). There were no substantial differences between the two groups in the mean score rate of multiple-choice questions and the short essay category (p > 0.05); however, there were notable differences in the mean score rate of case analysis questions and identification of structure of tissue (p < 0.05). The questionnaire results indicate that the VM system improves students’ productivity and promotes learning efficiency. Furthermore, students reported other positive effects of the VM system in terms of additional learning resources, critical thinking, ease of communication and confidence.ConclusionsThe VM system is an effective tool at Chinese medical university to promote undergraduates’ active learning and problem-solving skills as an assisted teaching platform.

Osteosarcoma is the most common primary bone tumor. Recent data indicated miRNAs may be involved in the pathogenesis of osteosarcoma, suggesting some novel targets for therapy. It is known that miR-429 is down-regulated and functions as a tumor suppressor by targeting c-myc and PLGG1 in gastric and breast cancer. However, the exact role of miR-429 in osteosarcoma remained unknown. In our study, we found MiR-429 was down-regulated in primary osteosarcoma lesion and osteosarcoma cell lines. Moreover, MiR-429 can inhibit the proliferation of osteosarcoma cell lines and induce more cell apoptosis. Also, we discovered MiR-429 plays a role in osteosarcoma by binding the 3'UTR of zinc finger E-box-binding homeobox 1 (ZEB1) mRNA, and that overexpression of ZEB1 could reverse the proliferation, subsequently blocking effect of miR-429. In conclusion, miR-429 serves as a tumor suppressor via interaction with ZEB1. Our finding may provide a new target for osteosarcoma therapy.

BackgroundDespite great advances, China’s postgraduate education faces many problems, for example traditional lecture-based learning (LBL) method provides fewer oppotunities to apply knowledge in a working situation. Task-based learning (TBL) is an efficient strategy for increasing the connections among skills, knowledge and competences. This study aimed to evaluate the effect of a modified TBL model on problem-solving abilities among postgraduate medical students in China.MethodsWe allocated 228 first-year postgraduate students at Third Military Medical University into two groups: the TBL group and LBL group. The TBL group was taught using a TBL program for immunohistochemistry. The curriculum consisted of five phases: task design, self-learning, experimental operations, discussion and summary. The LBL group was taught using traditional LBL. After the course, learning performance was assessed using theoretical and practical tests. The students’ preferences and satisfaction of TBL and LBL were also evaluated using questionnaires.ResultsThere were notable differences in the mean score rates in the practical test (P < 0.05): the number of high scores (>80) in the TBL group was higher than that in the LBL group. We observed no substantial differences in the theoretical test between the two groups (P > 0.05). The questionnaire results indicated that the TBL students were satisfied with teaching content, teaching methods and experiment content. The TBL program was also beneficial for the postgraduates in completing their research projects. Furthermore, the TBL students reported positive effects in terms of innovative thinking, collaboration, and communication.ConclusionsTBL is a powerful educational strategy for postgraduate education in China. Our modified TBL imparted basic knowledge to the students and also engaged them more effectively in applying knowledge to solve real-world issues. In conclusion, our TBL established a good foundation for the students’ future in both medical research and clinical work.Electronic supplementary materialThe online version of this article (10.1186/s12909-017-0994-0) contains supplementary material, which is available to authorized users.