Central nervous system metastasis from osteosarcoma: Case report and literature review

Survival outcomes of patients with brain metastasis of osteosarcoma can be improved by aggressive multi-disciplinary interventions including chemotherapy

BACKGROUND/OBJECTIVE

Brain metastasis in osteosarcoma (BMO) is rare and its clinical characteristics are often buried among studies on brain metastasis of bone and soft tissue sarcomas. The aim of the present study was to summarize the incidence, clinical characteristics, treatment and outcomes of patients with BMO.

METHODS

This retrospective study included 7 patients with BMO who received treatment in our center between 2005 and 2019. The clinical medical records of the 7 patients, together with data of 70 BMO patients published in 33 articles and retrieved by means of PubMed and Medline, were analyzed, retrospectively.

RESULTS

Data analysis of the 97 BMO patients showed a high correlation between the interval from the primary diagnosis to BMO occurrence and the interval from the primary diagnosis to prior metastases. Multivariate analysis showed that chemotherapy, radiotherapy and surgery were three main factors affecting the overall survival of BMO patients (HR = 0.427; HR = 0.372; HR = 0.296). Surgery combined with chemotherapy or radiotherapy offered a better overall survival than surgery alone.

CONCLUSION

Patients with BMO may obtain survival benefits from regular neuroimaging and early aggressive multi-disciplinary interventions including surgical resection, postoperative radiotherapy and chemotherapy.

SYNOPSIS

This is a retrospective study describing the characteristics of metastasic intervals, locations, clinical features and prognosis in 97 patients with brain metastasis of osteosarcoma (BMO). Multivariate analysis showed that chemotherapy was effective as surgery and radiotherapy for the treatment of BMO. Our findings emphasize the importance of regular neuroimaging and early aggressive multi-disciplinary interventions including surgical resection, postoperative radiotherapy and chemotherapy.

Analysis of the subcellular location of FAM230B and its interaction with premature miR-302b in osteosarcoma

INTRODUCTION

FAM230B has been characterized as an oncogenic lncRNA in papillary thyroid cancer and gastric cancer, while its role in osteosarcoma (OS) is unclear. This research was conducted to analyze the interaction between FAM230B and miR-302b in OS.

MATERIALS AND METHODS

Paired OS and non-tumor tissues donated by 58 OS patients were subjected to RNA preparation and RT-qPCR to quantify the expression of FAM230B and miR-302b (both mature and premature). The subcellular location of FAM230B and its interaction with premature miR-320b were analyzed by cellular fractionation assay and RNA pull-down assay, respectively. The roles of FAM230B and miR-302b in OS cell movement were evaluated using Transwell assay.

RESULTS

Increased FAM230B and premature miR-302b and decreased mature miR-302b were observed in OS. FAM230B was detected in both nuclear and cytoplasm samples and directly interacted with premature miR-302b. FAM230B overexpression in OS cells 143B and HOS decreased miR-302b maturation and increased cell invasion and migration, while miR-302b overexpression suppressed cell invasion and migration. FAM230B silencing restrained cell invasion and migration, and miR-302b inhibitor accelerated cell invasion and migration. MiR-302b knockdown significantly reversed the suppressive effects of shFAM230B on migration and invasion of 143B and HOS cells.

CONCLUSION

FAM230B is accumulated to high levels in OS and may serve as an endogenous competing RNA for premature miR-302b in the nucleus to promote OS cell invasion and migration.

Cerebral metastasis from osteosarcoma: “Bone” in the brain

Although brain metastases from bone and soft tissue sarcoma are uncommon, advances in sarcoma treatment have led to an increasing incidence of them. We present a 23-year-old male with a history of metastatic femoral osteosarcoma, who presented with headache and unsteady gait and was diagnosed with a cerebellar metastasis. CT scan revealed a mass in the left cerebellar parenchyma with large intralesional central calcification and perilesional edema. Corticosteroid treatment led to neurological symptoms resolution, with a rapid tapering. The patient had also lung metastases and we opted to administer systemic treatment with the tyrosine kinase inhibitor cabozantinib. Given the relative radioresistance of osteosarcomas, the patient did not receive radiation therapy.

Microvesicles derived from human bone marrow mesenchymal stem cells promote U2OS cell growth under hypoxia: the role of PI3K/AKT and HIF-1α

Studies have demonstrated that mesenchymal stem cells (MSCs) can promote tumor growth, and MSC microvesicles (MVs) are very important in the tumor microenvironment and information transfer between cells during tumorigenesis and development. However, the potential effects and mechanisms of MSC-MVs on tumor growth are still controversial. Here in this study, we investigated the roles and effects of human bone marrow MSC-MVs (hBMSC-MVs) on human osteosarcoma (U2OS) cell growth under hypoxia in vitro and in vivo. BMSC-MVs were harvested and purified by ultracentrifugation. U2OS cells were treated with different concentrations of hBMSC-MVs under hypoxia. Cell viability and migration was measured by MTT test, transwell invasion assay and scratch migration assay. The expression of the signaling molecules of AKT, VEGF, GLUT1 and Bax, cleaved-caspase3 in U2OS cells cultured with MVs under hypoxia was determined by western blot. U2OS/siHIF-1α or U2OS/NC cells mixed with/without MVs were subcutaneously injected into nude mice; the tumor size and weight were detected. We found that hBMSC-MVs promoted U2OS cell proliferation and migration under hypoxia in vitro, and that was partially associated with the PI3K/AKT and HIF-1α pathways. MVs co-injected with U2OS cells promoted tumor growth in a mouse xenograft model. siHIF-1α transfection reversed these changes to some extent. The function of hBMSC-MVs on U2OS cell progression and tumor growth was associated with PI3K/AKT and HIF-1α pathway under hypoxia. These findings support a new mechanism suggesting the contribution of MSC-MVs to tumor growth.