Project description:Improved treatment strategies for sarcoma rely on clarification of the molecular mediators of disease progression. Recently, we identified the secreted glycoprotein NELL1 modulates osteosarcoma (OS) disease progression in part via altering the sarcomatous extracellular matrix and cell-ECM interactions. Of known NELL1 interactor proteins, Contactin-associated protein-like 4 (Cntnap4) encodes a member of the neurexin superfamily of transmembrane molecules best known for its presynaptic functions in the central nervous system. Here, CRISPR/Cas9 gene deletion of CNTNAP4 reduced OS tumor growth, sarcoma-associated angiogenesis, and pulmonary metastases. CNTNAP4 knockout (KO) in OS tumor cells largely phenocopied the effects of NELL1 KO, including reductions in sarcoma cell attachment, migration, and invasion. Moreover, CNTNAP4 KO cells were unresponsive to the effects of NELL1 treatment. Transcriptomic analysis combined with protein phosphoarrray demonstrated notable reductions in MAPK signaling with CNTNAP4 deletion, the ERK agonist isoproterenol restored OS cell functions among CNTNAP4 KO tumor cells. Finally, human primary cells and tissues in combination with publicly available sequencing data confirmed the significance of CNTNAP4 signaling in human sarcomas. In summary, our findings demonstrate the biological importance of NELL-1/CNTNAP4 signaling in disease progression of human sarcomas and suggest that targeting NELL-1/CNTNAP4 signaling represents a strategy with therapeutic benefit in sarcoma patients.
Project description:Sarcomas produce abnormal extracellular matrix (ECM) which in turn provides instructive cues for cell growth and invasion. Neural EGF Like-Like molecule 1 (NELL-1) is a secreted glycoprotein characterized by its non-neoplastic osteoinductive effects, yet highly expressed in skeletal sarcomas. Here, NELL1 gene deletion markedly reduced invasive behavior across human osteosarcoma (OS) cell lines. This resulted in reduced OS disease progression, inhibited metastatic potential and improved survival in a xenograft model. These observations were recapitulated with Nell1 conditional knockout in mouse models of p53/Rb driven sarcomagenesis, including reduced tumor frequency, and extended tumor free survival. Transcriptomic and phospho-proteomic analysis demonstrated NELL1 loss skews the expression of matricellular proteins associated with reduced FAK signaling. Culture on OS enriched matricellular proteins reversed phenotypic and signaling changes among NELL1 knockout sarcoma cells. These findings in mouse and human models suggest that NELL-1 expression alters the sarcoma matrix, thereby modulating cellular invasive potential and prognosis. Disruption of NELL-1 signaling may represent a novel therapeutic approach to short circuit sarcoma disease progression.
Project description:It has been reported that GLI2 promotes proliferation, migration, and invasion of mesenchymal stem cell and osteosarcoma cells. To examine the molecular mechanisms of GLI2-mediated osteosarcoma metastasis, we performed a microarray analysis. The gene encoding ribosomal protein S3 (RPS3) was identified as a target of GLI2. Real-time PCR revealed that RPS3 was upregulated in osteosarcoma cell lines compared with normal osteoblast cells. Knockdown of GLI2 decreased RPS3 expression, whereas forced expression of a constitutively active form of GLI2 upregulated the expression of RPS3. RPS3 knockdown by siRNA decreased the migration and invasion of osteosarcoma cells. Although forced expression of constitutively active GLI2 increased the migration of human mesenchymal stem cells, knockdown of RPS3 reduced the up-regulated migration. In contrast, forced expression of RPS3 increased migration and invasion of osteosarcoma cells. Moreover, reduction of migration by GLI2 knockdown was rescued by forced expression of RPS3. Immunohistochemical analysis showed that RPS3 expression was increased in primary osteosarcoma lesions with lung metastases compared with those without. These findings indicate that GLI2–RPS3 signaling may be a marker of invasive osteosarcoma and a therapeutic target for patients with osteosarcoma.
Project description:Since its first identification in prostate cancers and prostate tissues, transient receptor potential melastatin-subfamily member 8 (TRPM8) is subsequently found to be overexpressed in a wide range of cancers and is shown to be implicated in tumorigenesis and tumor progression. Here, we used N-(3-aminopropyl)-2-[(3-methylphenyl) methoxy] -N-(2-thienylmethyl) benzamide hydrochloride (AMTB), a specific TRPM8 antagonist, to explore its antitumoral effect on osteosarcoma. We find that AMTB suppress osteosarcoma cell proliferation, metastasis and induce cellular apoptosis. Xenograft model in nude mice experiments also define that AMTB can increase the sensitivity of tumor cells to cisplatin, the cytotoxic chemotherapeutic regimens in treating osteosarcoma. Molecularly, AMTB specific antagonizes TRPM8 which is upregulated in osteosarcoma and its expression level in osteosarcoma tissues is negatively related to patients’ prognosis. Finally, RNA sequencing analysis was performed to explore the mechanism underlying the antitumoral effect of AMTB on osteosarcoma cells and the results prove that AMTB suppresses the Transforming Growth Factor β (TGFβ) signaling pathway. Our study provides evidence that TRPM8 could be a potential therapeutic target and AMTB can suppress growth and metastasis of osteosarcoma cells through repressing the TGFβ signaling pathway and increase the sensitivity of tumor cells to cisplatin.
Project description:Osteosarcoma is the most common primary bone sarcoma. About 50% of patients develop metastatic disease and their 5-year survival lingers at around 20-30%. T cell checkpoint blockade immunotherapies have revolutionized cancer treatment in the last decade, but their impact remains limited in osteosarcoma. In order to reveal potentially novel immunotherapeutic strategies for advanced osteosarcoma, we conducted an immunogenomic characterization of a unique sample set comprising multiple osteosarcoma samples from seven patients, collected throughout the progression of the disease. We performed RNA-sequencing and imaging mass cytometry analysis on those samples to reveal the immunological landscape during osteosarcoma progression. Transcriptional and phenotypical hallmarks of cytotoxic T cell-driven anti-cancer immunity were enriched in metastatic lesions as compared to primary tumors. In parallel, we found a pronounced increase in the expression of cancer testis antigens, particularly MAGEA-related antigens, in osteosarcoma metastases. Their overexpression in metastatic lesions was confirmed at protein level and positive expression of MAGEA3 in primary tumors showed a significant association with metastasis free survival. Importantly, we demonstrated the presentation of MAGE-derived peptides in three osteosarcoma cell lines. These findings indicate a concurrent augmentation of cytotoxic anti-tumor immune responses and expression of MAGEA antigens from primary to metastatic osteosarcoma. This observation warrants the exploration of MAGEA antigens as potential targets for immunotherapy in the treatment of advanced osteosarcoma.