The physiological role of microRNAs (miRNAs) in osteoblast differentiation remains elusive. Exosomal miRNAs isolated from human bone marrow-derived mesenchymal stem cells (BMSCs) culture were profiled using miRNA arrays containing probes for 894 human matured miRNAs. Seventy-nine miRNAs (∼8.84%) could be detected in exosomes isolated from BMSC culture supernatants when normalized to endogenous control genes RNU44. Among them, nine exosomal miRNAs were up regulated and 4 miRNAs were under regulated significantly (Relative fold>2, p<0.05) when compared with the values at 0 day with maximum changes at 1 to 7 days. Five miRNAs (miR-199b, miR-218, miR-148a, miR-135b, and miR-221) were further validated and differentially expressed in the individual exosomal samples from hBMSCs cultured at different time points. Bioinformatic analysis by DIANA-mirPath demonstrated that RNA degradation, mRNA surveillance pathway, Wnt signaling pathway, RNA transport were the most prominent pathways enriched in quantiles with differential exosomal miRNA patterns related to osteogenic differentiation. These data demonstrated exosomal miRNA is a regulator of osteoblast differentiation.

No abstract

Background: The complexity of breast cancer at the clinical, morphological and genomic levels has been extensively studied in the western population. However, the mutational genomic profiles in Chinese breast cancer patients have not been explored in any detail.Methods: We performed targeted sequencing using a panel consisting of 33 breast cancer-related genes to investigate the genomic landscape of 304 consecutive treatment-naïve Chinese breast cancer patients at Guangdong Provincial People's Hospital (GDPH), and further compared the results to those in 453 of Caucasian breast cancer patients from The Cancer Genome Atlas (TCGA). Results:The most frequently mutated gene was TP53 (45%), followed by PIK3CA (44%), GATA3 (18%), MAP3K1 (10%), whereas the copy-number amplifications were frequently observed in genes of ERBB2 (24%), MYC (23%), FGFR1 (13%) and CCND1 (10%). Among the 8 most frequently mutated or amplified genes, at least one driver was identifiable in 87.5% (n=267) of our GDPH cohort, revealing the significant contribution of these known driver genes in the development of Chinese breast cancer. Compared to TCGA data, the median age at diagnosis in our cohort was significantly younger (48 vs. 58 years; P<0.001), while the distribution of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) statuses were similar. The largest difference occurred in HR+/HER2-subtype, where 8 of the 10 driver genes compared had statistically significant differences in their frequency, while there were differences in 2 of 10 driver genes among the TNBC and HR+/HER2+ group, but none in the HR-/HER2+ patients in our cohort compared to the TCGA data. Collectively, the most significant genomic difference was a significantly higher prevalence for TP53 and AKT1 in Chinese patients. Additionally, more than half of TP53-mutation HR+/HER2-Chinese patients (~60%) are likely to harbor more severe mutations in TP53, such as nonsense, indels, and splicing mutations. Conclusions:We elucidated the mutational landscape of cancer genes in Chinese breast cancer and further identified significant genomic differences between Asian and Caucasian patients. These results should improve our understanding of pathogenesis and/or metastatic behavior of breast cancer across races/ ethnicities, including a better selection of targeted therapies. Zhang et al. 33-gene panel characterization of Chinese breast tumors

Osteosarcoma is the most common bone tumors in children and adolescents. Despite intensive chemotherapy, patients with advanced disease still have a poor prognosis, illustrating the need for alternative therapies. In this study, we explored the use of antibodies that block CD47 with a tumor growth suppressive effect on osteosarcoma. We first found that up-regulation of CD47 mRNA levels in the tumorous tissues from eight patients with osteosarcoma when compared with that in adjacent non-tumorous tissues. Further western-blot (WB) and immunohistochemistry (IHC) demonstrated that CD47 protein level was highly expressed in osteosarcoma compared to normal osteoblastic cells and adjacent non-tumorous tissues. Osteosarcoma cancer stem cell markers staining shown that the majority of CD44+ cells expressed CD47 albeit with different percentages (ranging from 80% to 99%). Furthermore, high CD47 mRNA expression levels were associated with a decreased probability of progression-free and overall survival. In addition, blockade of CD47 by specific Abs suppresses the invasive ability of osteosarcoma tumor cells and further inhibits spontaneous pulmonary metastasis of KRIB osteosarcoma cells in vivo. Finally, CD47 blockade increases macrophage phagocytosis of osteosarcoma tumor cells. In conclusion, our findings demonstrate that CD47 is a critical regulator in the metastasis of osteosarcoma and suggest that targeted inhibition of this antigen by anti-CD47 may be a novel immunotherapeutic approach in the management of this tumor.

Background HER2-low breast cancers were reported to have distinct clinicopathological characteristics from HER2-zero; however, the difference in their genetic features remains unclear. This study investigated the clinical and molecular features of breast tumors according to HER2 status. Methods We analyzed the clinicopathological and genomic data of 523 Chinese women with breast cancer. Genomic data was generated by targeted next-generation sequencing (NGS) of breast tumor samples using a commercial 520 gene panel. The cohort was stratified according to HER2 status as HER2-zero (n = 90), HER2-low (n = 231), and HER2-positive (n = 202) according to their immunohistochemistry and fluorescence in situ hybridization results. Results HER2-low breast tumors were enriched with hormone receptor-positive tumors, and who had lower Ki67 expression levels. Genes were differentially mutated across HER2 subgroups. HER2-low tumors had significantly more mutations involved in PI3K-Akt signaling than HER2-positive (p < 0.001) and HER2-zero breast tumors (p < 0.01). HER2-zero tumors had more mutations in checkpoint factors (p < 0.01), Fanconi anemia (p < 0.05), and p53 signaling and cell cycle pathway (p < 0.05) compared to HER2-low breast tumors. Compared with HER2-zero tumors, HER2-low tumors had significantly lower pathological complete response rates after neoadjuvant therapy (15.9% vs. 37.5%, p = 0.042) and proportion of relapsed/progressed patients across follow-up time points (p = 0.031), but had comparable disease-free survival (p = 0.271). Conclusion Our results demonstrate the distinct clinical and molecular features and clinical outcomes of HER2-low breast tumors.

Apolipoprotein E (APOE) ε4 allele and sigma-1 receptor (SIGMAR1) c.5C (Q2P) polymorphisms have been acknowledged as risk factors for developing Alzheimer's disease (AD). However, whether these polymorphisms influence the disease process is unclear. Therefore, two cohorts with a clinical diagnosis of AD were recruited, a postmortem confirmed Australian cohort (82 cases) from the Australian Brain Bank Network, and a Chinese cohort with detailed clinical assessments recruited through an epidemiology study in Shanghai and through the neurology department outpatients clinic of Shanghai Ruijin Hospital (330 cases). SIGMAR1 Q2P and APOE genotyping was performed on all cases. Dementia severity in the Chinese cohort was assessed using MMSE scores, and the stages of senile plaques and neurofibrillary tangles (NFT) assessed in the Australian cohort. Associations between SIGMAR1 Q2P and APOE genotypes and disease severity were assessed using SPSS. Results confirmed that APOE 4 allele associated with increased NFT stages and cognitive decline, with carriers with one APOE ε2 or ε3 allele often having better clinical outcomes compared to carriers with none or two ε2 or ε3 alleles respectively. SIGMAR1 c.5C polymorphism alone did not associate with MMSE score variability in Chinese or with pathological stages in Caucasians. However, the association studies revealed a significant genetic interaction between the APOE ε4 allele and SIGMAR1 2P carriers in both populations, i.e., in APOE non ε4 allele carriers, SIGMAR1 2P variant had increased cognitive dysfunction and more advanced stages of NFT. Our data demonstrate that SIGMAR1 and APOE interact to influence AD severity across ethnic populations.

Idiopathic scoliosis is the most common pediatric spinal deformity affecting 1% to 3% of the population, and adolescent idiopathic scoliosis (AIS) accounts for approximately 80% of these cases; however, the etiology and pathogenesis of AIS are still uncertain. The current study aims to identify the relationship between G protein-coupled receptor 126 (GPR126) gene and AIS predisposition, to identify the relationship between the genotypes of the GPR126 SNPs and the clinical phenotypes of AIS. We conducted a case-control study and genotyped twenty SNPs of GPR126 gene including ten exonic SNPs and ten intronic polymorphisms in 352 Chinese sporadic AIS patients and 149 healthy controls. We provided evidence for strong association of three intronic SNPs of the GPR126 gene with AIS susceptibility: rs6570507 A > G (p =0 .0035, OR = 1.729), rs7774095 A > C (p = 0.0078, OR = 1.687), and rs7755109 A > G (p = 0.0078, OR = 1.687). However, we did not identify any significant association between ten exonic SNPs of GPR126 and AIS. Linkage disequilibrium analysis indicated that rs7774095 A > C and rs7755109 A > G could be parsed into one block. The association between the intronic haplotype and AIS was further confirmed in an independent population with 110 AIS individuals and 130 healthy controls (p = 0.046, OR = 1.680). Furthermore, molecular mechanisms underlying intronic SNP regulation of GPR126 gene were studied. Although intronic SNPs associated with AIS didn't influence GPR126 mRNA alternative splicing, there was a strong association of rs7755109 A > G with decreased GPR126 mRNA level and protein levels. Our findings indicate that genetic variants of GPR126 gene are associated with AIS susceptibility in Chinese populations. The genetic association of GPR126 gene and AIS might provide valuable insights into the pathogenesis of adolescent idiopathic scoliosis.

No abstract