Identification of key biomarkers and functional pathways in osteosarcomas with lung metastasis: Evidence from bioinformatics analysis

Machine learning and experimental analyses identified miRNA expression models associated with metastatic osteosarcoma

Osteosarcoma (OS), as the most common primary bone cancer, has a high invasiveness and metastatic potential, therefore, it has a poor prognosis. This study identified early diagnostic biomarkers using miRNA expression profiles associated with osteosarcoma metastasis. In the first step, we used RNA-seq and online microarray data from osteosarcoma tissues and cell lines to identify differentially expressed miRNAs. Then, using seven feature selection algorithms for ranking, the first-ranked miRNAs were selected as input for five machine learning systems. Using network analysis and machine learning algorithms, we developed new diagnostic models that successfully differentiated metastatic osteosarcoma from non-metastatic samples based on newly discovered miRNA signatures. The results showed that miR-34c-3p and miR-154-3p act as the most promising models in the diagnosis of metastatic osteosarcoma. Validation for this model by RT-qPCR in benign tissue and osteosarcoma biopsies confirmed the lower expression of miR-34c-3p and miR-154-3p in OS samples. In addition, a direct correlation between miR-34c-3p expression, miR-154-3p expression and tumor grade was discovered. The combined values of miR-34c-3p and miR-154-3p showed 90 % diagnostic power (AUC = 0.90) for osteosarcoma samples and 85 % (AUC = 0.85) for metastatic osteosarcoma. Adhesion junction and focal adhesion pathways, as well as epithelial-to-mesenchymal transition (EMT) GO terms, were identified as the most significant KEGG and GO terms for the top miRNAs. The findings of this study highlight the potential use of novel miRNA expression signatures for early detection of metastatic osteosarcoma. These findings may help in determining therapeutic approaches with a quantitative and faster method of metastasis detection and also be used in the development of targeted molecular therapy for this aggressive cancer. Further research is needed to confirm the clinical utility of miR-34c-3p and miR-154-3p as diagnostic biomarkers for metastatic osteosarcoma.

The neurological and non-neurological roles of the primary microcephaly-associated protein ASPM

Primary microcephaly (MCPH), is a neurological disorder characterized by small brain size that results in numerous developmental problems, including intellectual disability, motor and speech delays, and seizures. Hitherto, over 30 MCPH causing genes (MCPHs) have been identified. Among these MCPHs, MCPH5, which encodes abnormal spindle-like microcephaly-associated protein (ASPM), is the most frequently mutated gene. ASPM regulates mitotic events, cell proliferation, replication stress response, DNA repair, and tumorigenesis. Moreover, using a data mining approach, we have confirmed that high levels of expression of ASPM correlate with poor prognosis in several types of tumors. Here, we summarize the neurological and non-neurological functions of ASPM and provide insight into its implications for the diagnosis and treatment of MCPH and cancer.

A natural halogenated fluoride adenosine analog 5'-fluorodeoxy adenosine induced anticolon cancer activity in vivo and in vitro

Adenosine (ADO) and its analogs have been introduced into the anticancer clinical trials, especial for the ADO derivatives with fluoride. The biosynthesis of fluorinase produces a fluorine-containing ADO analog 5'-fluorodeoxy adenosine (5'-FDA). The toxicity and application of 5'-FDA has not been evaluated, which limits the application of ADO analogs. In order to study its potential mechanism, we carried out the following experiments. In our research, 5'-FDA displayed good antitumor activity in colon cancer cells and two colon cancer models. As a result, 5'-FDA concentration-dependently inhibited the proliferation, migration, and invasion in colon cancer cells through its proapoptosis and cell cycle arrest pathway. Furthermore, 5'-FDA inhibited the growth of colon cancer and its pulmonary metastasis in CT26 inbred mice without affecting their body weight. It was found that 5'-FDA remarkably increased the protein levels of Caspase 3 and cleaved-Caspase 9 and decreased Cyclin A2 and CDK2 via the regulation of p53 signaling pathway, and increased the protein levels of Caspase 8 and cleaved-Caspase 8 which participated in apoptosis pathway. All in all, 5'-FDA displayed excellent therapeutic effects on colon cancer and its pulmonary metastasis. We believed that our study provided a theoretical basis for further preclinical research of 5'-FDA in the treatment of cancer.

A calpain-6/YAP axis in sarcoma stem cells that drives the outgrowth of tumors and metastases

Sarcomas include cancer stem cells, but how these cells contribute to local and metastatic relapse is largely unknown. We previously showed the pro-tumor functions of calpain-6 in sarcoma stem cells. Here, we use an osteosarcoma cell model, osteosarcoma tissues and transcriptomic data from human tumors to study gene patterns associated with calpain-6 expression or suppression. Calpain-6 modulates the expression of Hippo pathway genes and stabilizes the hippo effector YAP. It also modulates the vesicular trafficking of β-catenin degradation complexes. Calpain-6 expression is associated with genes of the G2M phase of the cell cycle, supports G2M-related YAP activities and up-regulated genes controlling mitosis in sarcoma stem cells and tissues. In mouse models of bone sarcoma, most tumor cells expressed calpain-6 during the early steps of tumor out-growth. YAP inhibition prevented the neoformation of primary tumors and metastases but had no effect on already developed tumors. It could even accelerate lung metastasis associated with large bone tumors by affecting tumor-associated inflammation in the host tissues. Our results highlight a specific mechanism involving YAP transcriptional activity in cancer stem cells that is crucial during the early steps of tumor and metastasis outgrowth and that could be targeted to prevent sarcoma relapse.

Prominin 1 Significantly Correlated with Bone Metastasis of Breast Cancer and Influenced the Patient’s Prognosis

Background

This study is aimed at identifying the important biomarkers associated with bone metastasis (BM) in breast cancer (BRCA).

Methods

The GSE175692 dataset was used to detect significant differential expressed genes (DEGs) between BRCA samples with or without BM, and DEG-related pathways were then explored. Further, we constructed the protein-protein interaction (PPI) network on GEGs and filtered 5 vital nodes. We then performed the Cox regression, Kaplan-Meier analysis, nomogram, and ROC curve to filter the most significant prognosis genes. The GSE14020 and GSE124647 datasets were used to verify the expression and prognostic value of hub genes, respectively. Finally, the gene set enrichment analysis (GSEA) was performed to reveal the potential mechanism.

Results

Totally, 74 DEGs were detected, which mainly correlated with infectious disease, signaling molecules, and interaction. The 5 important DEGs were then filtered, and the Cox regression further showed that 2 genes, including prominin 1 (PROM1) and C-C motif chemokine ligand 2 (CCL2), were related to the prognosis of BRCA metastasis patients. Especially, PROM1 presented a better prognostic performance on the survival probability of patients than CCL2. Verification analysis further confirmed the abnormal expression and significant prognostic influence of PROM1. Finally, GSEA revealed that PROM1 was negatively related to IGF1 and mTOR pathways in BRCA metastasis.

Conclusion

PROM1 was an important biomarker associated with BRCA bone metastasis and affected the prognosis of metastatic BRCA patients. It may play a vital role in metastatic BRCA by negatively regulating IGF1 and mTOR pathways.

Immunoseroproteomic profiling in autoantibody to ENO1 as potential biomarker in immunodiagnosis of osteosarcoma by serological proteome analysis (SERPA) approach

Osteosarcoma (OS) is the most common highly malignant primary solid bone tumor. Despite its relatively low incidence among cancers, it remains one of the most harmful primary malignant tumors in childhood and adolescence. It is now evident that serum autoantibodies against tumor-associated antigens (TAAs) could be used as serological cancer biomarkers in types of cancers. Serological proteome analysis (SERPA) approach was applied to profile anti-TAA autoantibody response in sera from patients with OS and normal human, as well as explore difference between this response. This approach can detect autoantibodies that could serve as clinical biomarkers and immunotherapeutic agents. Enzyme-linked immunosorbent assay (ELISA) and Western blotting were further used to validate the level of identified TAAs. ENO1 as a 47kD TAA in OS was identified and characterized by SERPA. Analysis of 172 serum samples with OS, osteochondroma (OC), and normal human sera (NHS) by ELISA showed higher frequency of anti-ENO1 autoantibodies in OS sera compared to others. Interestingly, decrease of ENO1 immunoreactivity was observed in most patients after treatments, which may imply a potential association between anti-ENO1 autoantibody titers and disease progression. Nine of twelve sera reacted strongly against purified ENO1, but three reacted weakly against purified ENO1, which indicated 75.0% sera with positive optimal density values from ELISA were consistently positive in Western blotting. The expression of ENO1 in OS tissues was evaluated by immunohistochemistry in tumor microarray. ENO1 was one of the autoantibodies that elicit autoimmune responses in OS and can be used as biomarkers in immunodiagnosis and progression of OS.