Design, synthesis and biological evaluation of novel macrocyclic derivatives bearing aniline pyrimidine scaffolds as EGFR-TKIs.

Based on EGFR-TKI Osimertinib as lead compound, a series of novel macrocyclic derivatives bearing aniline pyrimidine scaffolds were designed and synthesized by macrocyclization. Their structures were identified by 1H NMR, 13C NMR, 19F NMR and HRMS. The pharmacological activities of the target compounds were tested and the preliminary structure-activity relationship was discussed. Among them, 17-membered ring compound H1 displayed the best inhibitory activities against EGFRL858R/T790M and EGFRd746-750/T790M with IC50 value of 2.92 nM and 0.34 nM, respectively. Exhilaratingly, 17-membered ring compound H7 possessed the most potent antiproliferative activity against BaF3-EGFRdel19/T790M cell lines (IC50 = 0.035 µm), which rivaled that of Osimertinib (IC50 = 0.033 µm).

Multi-Layer Graph Attention Network for Sleep Stage Classification Based on EEG.

Graph neural networks have been successfully applied to sleep stage classification, but there are still challenges: (1) How to effectively utilize epoch information of EEG-adjacent channels owing to their different interaction effects. (2) How to extract the most representative features according to confused transitional information in confused stages. (3) How to improve classification accuracy of sleep stages compared with existing models. To address these shortcomings, we propose a multi-layer graph attention network (MGANet). Node-level attention prompts the graph attention convolution and GRU to focus on and differentiate the interaction between channels in the time-frequency domain and the spatial domain, respectively. The multi-head spatial-temporal mechanism balances the channel weights and dynamically adjusts channel features, and a multi-layer graph attention network accurately expresses the spatial sleep information. Moreover, stage-level attention is applied to easily confused sleep stages, which effectively improves the limitations of a graph convolutional network in large-scale graph sleep stages. The experimental results demonstrated classification accuracy; MF1 and Kappa reached 0.825, 0.814, and 0.775 and 0.873, 0.801, and 0.827 for the ISRUC and SHHS datasets, respectively, which showed that MGANet outperformed the state-of-the-art baselines.

[Nursing Digital Transformation: An Example of an Electronic Whiteboard in a Regional Hospital in Central Taiwan].

The electronic whiteboard system is an important part of smart medical care. This system has been digitized and upgraded gradually over time, and now functions as a dashboard, incorporating sound effects, touch control, image display, face recognition, and other functions that maximize usage efficiency. In hospitals, electronic whiteboards are specialized for dedicated use in one of two areas: nursing stations and wards. Those used in nursing stations may upload data into the medical information system based on departmental and institutional requirements. Systems are built to the specific needs of different clinical departments and thus differ widely in terms of settings and functionality. Therefore, hospitals should promote regular communication among doctors, nurses, and patients.

SERS and MALDI-TOF MS based plasma exosome profiling for rapid detection of osteosarcoma.

Osteosarcoma is the most frequent primary bone cancer, particularly among children and adolescents. The early diagnosis of osteosarcoma is significant for timely clinical treatment to reduce the mortality of patients. Exosomes play a significant role in intercellular communication and serve as promising biomarkers in liquid biopsy for the diagnosis and monitoring of tumors. Herein, we report the utility of surface-enhanced Raman scattering (SERS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for rapid identification of osteosarcoma. We firstly profiled the intrinsic SERS signals and MALDI-TOF mass fingerprints of different subgroups of extracellular vesicles (EVs) and the corresponding cells, demonstrating that the SERS signals and MALDI-TOF mass spectra of exosomes from different types of cells were more discriminative compared to those of large and medium EVs and the cells themselves. Then, we characterized plasma-derived exosomes of 15 osteosarcoma patients and 15 healthy volunteers using SERS and MALDI-TOF MS, revealing distinctive biochemical differences in the spectra. We further utilized a data fusion approach to combine the two types of spectroscopic techniques, differentiating osteosarcoma patients from healthy controls with higher precision than either technique. The results reveal that the non-invasive liquid biopsy method using SERS and MALDI-TOF MS fingerprinting of exosomes has great potential for rapid diagnosis of osteosarcoma.

Impaired Limb Functional Outcome of Peripheral Nerve Regeneration Is Marked by Incomplete Recovery of Paw Muscle Atrophy and Brain Functional Connectivity in a Rat Forearm Nerve Repair Model.

Skilled sensorimotor deficit is an unsolved problem of peripheral nerve injury (PNI) led by limb trauma or malignancies, despite the improvements in surgical techniques of peripheral nerve anastomosis. It is now accepted that successful functional recovery of PNI relies tremendously on the multilevel neural plasticity from the muscle to the brain. However, animal models that recapitulate these processes are still lacking. In this report, we developed a rat model of PNI to longitudinally assess peripheral muscle reinnervation and brain functional reorganization using noninvasive imaging technology. Based on such model, we compared the longitudinal changes of the rat forepaw intrinsic muscle volume and the seed-based functional connectivity of the sensorimotor cortex after nerve repair. We found that the improvement of skilled limb function and the recovery of paw intrinsic muscle following nerve regeneration are incomplete, which correlated with the functional connectivity between the primary motor cortex and dorsal striatum. Our results were highly relevant to the clinical observations and provided a framework for future investigations that aim to study the peripheral central sensorimotor circuitry underlying skilled limb function recovery after PNI.

Establishment of a dynamic osteosarcoma biobank: Ruijin experience.

Outcomes for patients with metastatic and recurrent osteosarcoma remain poor and a better understanding of the biology of this malignancy is critical to the development of prognostic biomarkers and novel therapies. The purpose of this study was to establish a biobank of osteosarcoma which has the potential of monitoring tumors dynamically with exosomes, to facilitate clinical and basic scientific research. The osteosarcoma biological specimen and clinical data of osteosarcoma were collected in Ruijin Hospital in two stages. In the first stage (2015-2017), the collection of tissue specimens and blood samples were performed at diagnostic biopsy, definitive surgery, recurrence and lung metastasis, according to the Children's Oncology Group protocol. In the second stage (2017-2019), the tissue specimens were collected the same as before, but the blood samples were collected at the beginning of each MAP-I (methotrexate, cisplatin, doxorubicin, ifosfamide) chemotherapy cycle, and every 6 months after the last chemotherapy up to 3 years, according to our modified protocol, to dynamically monitor the status of possible alteration of gene expression profiling in the osteosarcoma. A total of 268 patients with osteosarcoma were enrolled in this study, 161 were men and 107 were women, with the mean age of 24.51 ± 15.58 years. Local recurrence occurred in 29 patients and lung metastasis in 51. The numbers of tissue and blood specimens reached 360 and 1023, respectively. 11 specimens were from recurrent osteosarcoma and 25 were from lung metastasis. The corresponding clinical and demographic data were collected in our electronic database. The osteosarcoma biobank built with our modified protocol mentioned above has the potential of monitoring tumors dynamically with exosomes and could provide specimens to the researches improving the biological understanding and outcome of this disease.

[Using Healthcare Failure Mode and Effects Analysis to Reduce Intra-Arterial Thrombectomy Preoperative Preparation Error Rates in the Emergency Room].

BACKGROUND & PROBLEMS: Intra-arterial thrombectomy (IAT) is a novel surgery that may restore cerebral blood flow in patients with ischemic stroke and lower the risks of permanent brain damage and disability. Because the process of preoperative preparation for IAT is complicated, error rates for this process have been reported in previous studies to be as high as 100%. Although these errors did not result in serious damage to patients, the risk to patient safety remains. Therefore, reducing the error rate for IAT preoperative preparation is necessary to improve patient safety. PURPOSE: To reduce the rate of IAT preoperative preparation error in an emergency room. RESOLUTION: This project applied healthcare failure mode and effect analysis (HFMEA) to evaluate the potential risks of IAT preoperative preparation in an emergency room. Based on the resultant hazard score, critical preventive measures were adopted, including creating a quick response code consent form, designing order packages, developing a checklist form, modifying stroke operating procedures and policies, planning suitable education content for staffs, developing criteria for evaluating preoperative preparation procedures, and installing vital signs equipment. RESULTS: After implementation of these measures, the hazard scores of 13 out of the 16 potential failure causes decreased to < 8, and the progress rate was 81.3%. The follow-up error rate for preoperative preparation was 0% in October 2019, which fulfilled the goal of this project. CONCLUSIONS: Preoperative preparation for IAT is complicated and time-consuming. In this project, HFMEA was introduced to ensure that preoperative preparation was accomplished in a complete and timely manner. Based on the results, after implementation, preparation work was effectively completed and operations were performed on schedule. Other hospitals may consider using this tool to evaluate potential risks to patient safety and to develop solutions to improve the quality of healthcare processes.

Establishment and validation of a novel survival prediction scoring algorithm for patients with non-small-cell lung cancer spinal metastasis.

BACKGROUND: This study was to develop an algorithm capable of predicting the survival of patients with NSCLC spinal metastasis for individualized therapy. METHODS: We identified 176 consecutive patients with NSCLC spinal metastasis between 2006 and 2017. Twenty-four features, including age, gender, smoking, KPS, paralysis, histological subtype, tumor stage, surgery, EGFR status, CEA, CA125, CA19-9, NSE, SCC, CYFRA21-1, calcium, AKP, albumin, the number of spinal, extra-spinal bone and visceral metastasis, time to metastasis, pathological fracture, and primary or secondary metastasis, were retrospectively analyzed. Features associated with survival in the multivariate analyses were included in a scoring model, which was prospectively validated in another 63 patients (NCT03363685). RESULTS: The median follow-up period was 12.00 months (interquartile range 6.00-23.40 months). One hundred forty-seven patients died during follow-up, with a median survival of 13.6 months being observed. Multivariate analysis revealed that the following features were associated with survival: age, smoking, CA125, SCC, KPS, and EGFR status. A scoring system based on these features was created to stratify patients into low-risk (0-3), intermediate-risk (4-6) and high-risk (7-10) groups, whose estimated median survival times 29.10, 10.40 and 3.90 months, respectively. The Harrell's c-index was 0.72. Model validation supported this model's validity and reproducibility. CONCLUSIONS: In patients with NSCLC spinal metastasis, survival was associated with age, smoking, CA125, SCC, KPS, and EGFR status. A validated scoring system based on these features was devised that can predict the survival times of those patients. This scoring system provides a basis for applying the NOMS framework and for facilitating individual treatment.

Exosomal miR-675 from metastatic osteosarcoma promotes cell migration and invasion by targeting CALN1.

Exosomal microRNAs(miRNAs) transfer from tumor to stromal cells is reportedly associated with cancer progression and metastasis in various epithelial cancers. However, the role of exosomal miRNA in the metastasis of osteosarcoma(OS) -the most common bone malignancy-still largely remains unknown. In this study, we purified exosomes with a median size close to 100 nm from cell culture media as well as patient serum, and proved that exosomes derived from the metastatic, but not the non-metastatic OS cells increase the migration and invasion of non-malignant fibroblast cells (hFOB1.19) in vitro. Furthermore, the differential miRNA cargo between metastatic and non-metastatic OS is identified by small RNA sequencing and RT-PCR validation, we found a highly expression of exosomal, but not cellular miR-675 level in the metastatic OS cell-lines compared with non-metastatic counterparts. Meanwhile, we also found that exosomal miR-675 could down-regulate CALN1 expression in recipient cell, which may influence the invasion and migration of hFOB1.19. Finally, the up regulation serum exosomal miR-675 and down regulation of CALN1 in tumor specimen was also found to be associated with the metastatic phenotype in OS patients. Our findings indicate that the exosomal miR-675 is a gene associated with OS and serum exosomal miR-675 expression may serve as a novel biomarker for the metastasis of OS.

Extracellular Vesicle RNA Sequencing Reveals Dramatic Transcriptomic Alterations Between Metastatic and Primary Osteosarcoma in a Liquid Biopsy Approach.

BACKGROUND: Osteosarcoma (OS) is a highly metastasizing bone malignancy despite wide surgical resection of the primary lesion. A liquid biopsy approach to detect residual disease and identify therapeutic targets is still lacking. In this report, we aimed to track the metastasis of OS via extracellular vesicle (EV) RNA profiling in a non-invasive manner. METHODS: We applied RNA sequencing for 10 matched metastatic and primary OS EV samples, including two pairs of cell lines and three pairs of plasma, and compared the expressed mutation, gene expression, fusion transcript, and alternative splicing (AS) between metastatic and primary OS at the transcriptome-wide level. Additional paired tissue/EVs were sequenced and public datasets were used to validate the EV-based metastatic biopsy. RESULTS: EVs were characterized through size-profiling, immunolabeling, and morphological examination. A drastic increase of mutation burden was observed in metastatic OS versus the non-metastatic counterpart. Hierarchical clustering of the expression profiles differentiated the metastatic EVs from the non-metastatic, with a signature enriched in cell-adhesion signaling and tyrosine kinase pathways. Moreover, 30 cancer-related gene fusions were identified in EV RNA as AS events tend to be more frequently observed in metastatic EVs. Further investigation suggested that over 70% of expressed point mutations from EVs could be validated in paired cell line/EV and tissue/EV analyses, and the expression signature significantly predicted 5-year survivorship of 42 patients from a public dataset. CONCLUSION: We have demonstrated a liquid biopsy-based approach for tracking cancer transcriptomic alterations, which is a promising source of prognostic and therapeutic biomarkers for metastatic OS. CLINICAL TRIAL REGISTRATION: NCT03108677.

[The Spiritual Health Status and Spiritual Care Behaviors of Nurses in Intensive Care Units and Related Factors].

BACKGROUND: Patients suffer sudden and life-threatening conditions in intensive care units (ICU), which frequently result in traumatic changes in physical, mental, and spiritual health. Little research has been conducted on the spiritual health and spiritual care behaviors of nurses in ICU. PURPOSE: To explore the relationship among demographic characteristics, spiritual health, and spiritual care behaviors in ICU nurses. METHODS: A descriptive correlational research was used and 219 nurses from three teaching hospitals were enrolled as study participants. A structured questionnaire consisting of a demographic datasheet, a spiritual health scale, and a spiritual care behavior scale was used for data collection. SPSS for Windows version 22.0 was used for statistical analysis. RESULTS: The participants received few hours of spiritual-care education. The highest scored item for spiritual health was "connecting with people". The highest scored item for spiritual care behavior was "helping the patient out of adversity". Participants who were older in age and who had more years of clinical experience exhibited spiritual care behaviors such as "helping the patient out of adversity" and "retaining hope" more frequently with their ICU patients. CONCLUSIONS / IMPLICATIONS FOR PRACTICE: The older and more clinically experienced nurses in this study performed spiritual care behaviors at a higher frequency than their younger, less experienced counterparts. Therefore, it is recommended that hospitals retain more-experienced nursing staff to elevate the level of holistic health care. Concurrently, training in spiritual care skills should be provided to younger and less experienced nurses in order to facilitate more spiritual care behaviors. The results of this study provide a reference for providing spiritual care behaviors to patients.

Antitumor effect of focal adhesion kinase inhibitor PF562271 against human osteosarcoma in vitro and in vivo.

Focal adhesion kinase (FAK) overexpression is related to invasive and metastatic properties in different kinds of cancers. Target therapy by inhibiting FAK has achieved promising effect in some cancer treatments, but its effect in human osteosarcoma has not been well studied. In the present study, we analyzed the antitumor efficacy of PF562271, an FAK inhibitor, against osteosarcoma in vitro and in vivo. Phosphorylated FAK (Y397) was highly expressed in primary human osteosarcoma tumor samples and was associated with osteosarcoma prognosis and lung metastasis. PF562271 greatly suppressed proliferation and colony formation in human osteosarcoma cell lines. In addition, treatment of osteosarcoma cell lines with PF562271 induced apoptosis and downregulated the activity of the protein kinase B/mammalian target of rapamycin pathway. PF562271 also impaired the tube formation ability of endothelial cells in vitro. Finally, oral treatment with PF562271 in mice dramatically reduced tumor volume, weight, and angiogenesis of osteosarcoma xenografts in vivo. These results indicate that FAK inhibitor PF562271 can potentially be effectively used for the treatment of osteosarcoma.

Metformin inhibits the proliferation, metastasis, and cancer stem-like sphere formation in osteosarcoma MG63 cells in vitro.

Metformin is an oral drug that has been widely used to treat type 2 diabetes mellitus. Interestingly, accumulated evidence indicate that metformin may reduce the risk of cancer in patients with type 2 diabetes and inhibit tumor cell growth and survival in numerous malignancies, including osteosarcoma (OS) cells. In the present study, we aimed to investigate the effects of metformin on the proliferation, migration, invasion, and sphere formation in OS MG63 cells in vitro. Metformin suppressed OS MG63 cell proliferation in a dose- and time-dependent manner and markedly blocked anti-metastatic potentials, migration, and invasion, by downregulating matrix metalloproteinase 2 (MMP2) and MMP9. Besides, we established OS cancer stem-like cell (CSC) model with sarcosphere formation assay and demonstrated that metformin posed damage on CSCs in OS by inhibiting sphere formation and by inducing their stemness loss. The stemness of CSCs in OS such as self-renewal and differentiation potentials was both impaired with a significant decrease of Oct-4 and Nanog activation. Consistent with this, the positive rates of CD90, CD133, and stage-specific embryonic antigen-4 (SSEA-4) were all observed with reductions in response to metformin exposure. In addition, Western blot showed that metformin activated AMPKα at Tyr172, followed by a downregulated phosphorylation of mammalian target of rapamycin (mTOR)/S6 and feedback activation of p-AKT Ser(473) in both OS MG63 cells and CSCs. This indicates that AMPK/mTOR/S6 signaling pathway might be involved in the growth inhibition of both OS MG63 cells and CSCs. These results suggest that metformin, a potential anti-neoplastic agent, might make it a novel therapeutic choice for the treatment of OS in the future.

Open reduction and internal fixation of Ideberg IV and V glenoid intra-articular fractures through a Judet approach: a retrospective analysis of 11 cases.

OBJECTIVES: To evaluate the methods and the outcomes of complex intra-articular glenoid fractures, treated by open reduction and internal fixations. METHODS: The outcomes of 11 cases of complex intra-articular glenoid scapular fractures were retrospectively analyzed. The fractures were classified as type IV in five cases, type Va in two and Vb in four cases, according to Ideberg classification system. The mean step or gap between the main articular fragments was 6.3 ± 6.2 (4-25) mm. The fractures were openly reduced through a Judet approach and fixed with reconstructive plates or bands placed on the lateral and medial side of affected scapula, respectively. The main articular fragments were strengthened with a 4.0-mm cannulated screw in five cases. The bone union, the anterior flexion, the external and internal rotation of the shoulders were checked and recorded. The functional outcomes were evaluated using DASH questionnaire, Constant and UCLA shoulder score systems, respectively. RESULTS: 11 patients were followed up with an average of 28.2 ± 12.6 (12-50) months. All the fractures were united smoothly without second intervention. At the latest visiting, the mean anterior flexion of affected shoulder was 157.3 ± 7.37° (range 150°-170°), the mean external rotation of the affected shoulder was 58.2 ± 7.5° (range 50°-70°). When the shoulder in the internal rotation, the extended thumb reached to L4 or L1 or T10 or T7 in one case, to T12 in two cases and to T8 in four cases, respectively, the mean Constant score was 91.7 ± 2.8 (86-96) points. The mean UCLA score was 32.7 ± 1.7 (30-35) points, leading to four cases of excellent and seven cases of good results. The mean DASH score was 7.4 ± 3.3 (3.4-13) points. CONCLUSION: Good outcomes could be obtained when Ideberg IV and V glenoid fractures were treated by open reduction and internal fixation through a Judet approach.

Key genes associated with osteoporosis revealed by genome wide gene expression analysis.

Gene expression profiles of circulating monocytes were analyzed to identify key genes associated with osteoporosis. Raw microarray data were downloaded from gene expression omnibus under accession number GSE7158, including 8 microarray dataset for patients with high peak bone mass (PBM) and 8 for low PBM. Package linear models for microarray data of R was adopted to screen out differentially expressed genes (DEGs). Gene ontology enrichment analysis and Kyoto encyclopedia of genes and genomes pathway analysis were performed with plug-ins of cytoscape. Protein-protein interaction network was constructed using FunCoup. A total of 283 DEGs were identified in low-PBM group, including 135 up- and 148 down-regulated genes. A considerable part of DEGs were localized in plasma membrane. Several ion transport-related pathways were revealed, such as mineral absorption and carbohydrate digestion and absorption. A range of DEGs were identified and some of them were related to calcium transport as well as osteoporosis. These findings are helpful in disclosing the pathogenetic mechanisms of osteoporosis.

Hydrothermal preparation and characterization of ultralong strontium-substituted hydroxyapatite whiskers using acetamide as homogeneous precipitation reagent.

The ultralong strontium- (Sr-) substituted hydroxyapatite (SrHAp) whiskers were successfully prepared using acetamide as homogeneous precipitation reagent. The effect of the Sr substitution amount on the lattice constants and proliferation of human osteoblast cells (MG-63) was further investigated. The results showed that the SrHAp whiskers with diameter of 0.2-12 µm and ultralong length up to 200 µm were obtained and the Sr substitution level could be facilely tailored by regulating the initial molar ratio of Sr/(Sr + Ca) in raw materials. The Sr(2+) replaced part of Ca(2+) and the lattice constants increased apparently with the increase of the Sr substitution amount. Compared with the pure HAp whiskers, the Sr substitution apparently stimulated the proliferation of MG-63 at certain extracted concentrations. Our study suggested that the obtained SrHAp whiskers might be used as bioactive and mechanical reinforcement materials for hard tissue regeneration applications.

Multimodal Nature of the Single-cell Primate Brain Atlas: Morphology, Transcriptome, Electrophysiology, and Connectivity.

Primates exhibit complex brain structures that augment cognitive function. The neocortex fulfills high-cognitive functions through billions of connected neurons. These neurons have distinct transcriptomic, morphological, and electrophysiological properties, and their connectivity principles vary. These features endow the primate brain atlas with a multimodal nature. The recent integration of next-generation sequencing with modified patch-clamp techniques is revolutionizing the way to census the primate neocortex, enabling a multimodal neuronal atlas to be established in great detail: (1) single-cell/single-nucleus RNA-seq technology establishes high-throughput transcriptomic references, covering all major transcriptomic cell types; (2) patch-seq links the morphological and electrophysiological features to the transcriptomic reference; (3) multicell patch-clamp delineates the principles of local connectivity. Here, we review the applications of these technologies in the primate neocortex and discuss the current advances and tentative gaps for a comprehensive understanding of the primate neocortex.

Anthropometry of the proximal tibia of patients with knee arthritis in Shanghai.

We measured the resected bony surface of the proximal tibia from reconstructed 3D models of the 179 arthritis knees using CT data. We found that the mediolateral (ML) dimension (69.6 ± 9.2 mm) and anteroposterior (AP) dimension (46.1 ± 6.1 mm) were less than those of Westerners. It was observed the medial anteroposterior (MAP) dimension (47.1 ± 7.2 mm) was much larger and closer to middle point of ML dimension than lateral anteroposterior (LAP) dimension (42.9 ± 6.3 mm). The aspect ratio (AR) (1.5 ± 0.07) was constant in Shanghai population. Only half of the prostheses we used in clinic mostly matched the resected bony surface of Shanghai population very well in ML, AP and AR dimension.

[Inhibitory effect and significance of rapamycin on the mammalian target of rapamycin signaling pathway in osteosarcoma stem cells and osteosarcoma cells].

OBJECTIVE: To observe the effect of rapamycin on the MG-63 osteosarcoma cells (OC), osteosarcoma stem cells (OSC) and on mTOR signaling pathway, and explore the feasibility of rapamycin as a novel therapeutic measure in osteosarcoma chemotherapy regimens. METHODS: OC and OSC were cultured in vitro. Immunofluorescence assay was used to detect the expression of Nanog and Oct4 in OC and OSC. OC and OSC were treated with rapamycin in concentrations of 0, 20, 50 and 100 nmol/L. Semi-quantitative PCR and RT-PCR were used to detect the mTOR mRNA and CCK-8 assay was used to detect cell proliferation, and the cell morphology was observed under an inverted microscope. RESULTS: The cores of MG-63 cellular spheres exhibited embryonic stem cell characteristics such as Nanog and Oct4 expession. The mTOR pathway was activated in the OSC and the expression of mTOR mRNA was higher in OSC (0.761 ± 0.080) than that in OS (0.406 ± 0.090, P < 0.05) by semi-quantitative PCR. RT-PCR showed that the expression of mTOR mRNA was lower in OSCs treated with 100 nmol/L rapamycin (0.961 ± 0.060) than that with 0 nmol/L rapamycin (1.654 ± 0.246, P < 0.05). Cell counting kit-8 (CCK-8) assay showed that the proliferation of OC treated with 20, 50 and 100 nmol/L rapamycin was significantly inhibited, compared with that with 0 nmol/L rapamycin (P < 0.05). Compared with 0 nmol/L rapamycin, the proliferation of OSC treated with 20 and 50 nmol/L rapamycin was not significantly inhibited (P > 0.05), but that with 100 nmol/L rapamycin was significantly inhibited (P < 0.05). The invert microscopic observation revealed that rapamycin inhibited the formation of OSC spheres. CONCLUSIONS: Rapamycin can effectively inhibit cell proliferation and the ability of sphere formation of OSCs. It will provide a basis for a novel therapeutic approach in osteosarcoma chemotherapy regimens.