Osteosarcoma Metastases With Direct Cardiac Invasion: A Case Report and Review of the Pediatric Literature

Cardiac tumours in children: a single-centre experience and literature review

Cardiac tumours are extremely rare in children. Although more than 90% are benign, children can develop obstructive or embolisation derived symptoms, arrhythmias, constitutional symptoms, cardiac tamponade, or even sudden death. Although the majority are asymptomatic, and some spontaneously regress, appropriate follow-up is needed on a case-by-case basis, as patients may develop late symptoms. Definitive diagnosis is only possible through histological analysis; however, it is possible to infer tumour type with a high grade of certainty based on imaging features, particularly cardiac magnetic resonance. Surgical resection is advocated for those causing symptoms, obstruction, cardiac dysfunction, and high risk of embolisation. The aim of this review is to present the state of the art related to cardiac tumours in the paediatric population, in the context of our own experience.

Small direct right ventricular cardiac metastasis of osteosarcoma in a 10-year-old boy affirmed by cardiac MRI

Background

Metastatic osteosarcoma with direct cardiac involvement is an exceptionally rare finding. Reliable detection of cardiac metastases is known to be crucial for patients therapy and prognosis.

Case Summary

In a 10-year-old boy affected by osteosarcoma of the left femur, a baseline Fluorine-18-fluorodeoxy-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) was performed to assess the full extent of disease. Whole-body scan detected numerous bone metastases together with a single pulmonary metastasis. Moreover, increased tracer uptake was observed in the intracavitary right cardiac ventricle in the position of a subtle spot of calcification. Because of nondetectability of a cavitary lesion on echocardiography, cardiac magnetic resonance imaging (CMRI) examination was performed to evaluate cardiac ¹⁸F-FDG PET/CT finding. CMRI revealed a small nodule in the right ventricle attached to the trabeculae, highly suspicious of a direct cardiac metastasis. After 4 cycles of chemotherapy, complete regression of tracer uptake of the lesion was observed on a follow-up ¹⁸F-FDG PET/CT scan.

Conclusion

CMRI is able to detect even small, clinically asymptomatic cardiac metastases in young patients affected by osteosarcoma.

Cardiovascular recurrence of high-grade osteosarcoma presenting as atrial thrombosis and pulmonary embolism: A case report and review of the pediatric literature

In the era of neoadjuvant and adjuvant chemotherapy, extrapulmonary involvement by high-grade osteosarcoma (HGOS) is rare. Importantly however, HGOS metastasis in the form of cardiovascular tumor thrombus portends a dismal prognosis. Thus, prompt and accurate identification of tumor thrombus is crucial. We report here two unique cases of recurrent HGOS, presenting as thrombotic events, in order to increase awareness and index of suspicion among practitioners regarding this presentation. Additionally, we review 14 previously reported pediatric cases of cardiovascular metastatic HGOS.

Long Noncoding RNA SNHG16 Promotes Osteosarcoma Cells Migration and Invasion via Sponging miRNA-340

Long noncoding RNA host gene 16 (SNHG16) has a key role in a variety of cancer progression. However, the role and mechanism of SNHG16 in osteosarcoma (OS) remain unknown. In this study, we examined the functional role of SNHG16 in OS cells through knocked-down SNHG16 by using siRNA. We found that SNHG16 is overexpressed in OS tissues and cell lines. Inhibition of SNHG16 reduced OS cells proliferation, stimulated apoptosis, and decreased migration and invasion. In addition, SNHG16 reduced miR-340 expression in OS cells. The results showed that SNHG16 involves in the migration and invasion of OS cells through sponging miRNA-340. Together, our data support an important role of SNHG16 in regulating OS cell invasion and migration that highlights SNHG16 may be regarded as a potential target for OS treatment.

Inhibitory effect of icariin on osteosarcoma cell proliferation via the Wnt/β-catenin signaling pathway

Osteosarcoma, is a kind of malignant tumor derived from malignant interstitial cells. The pathogenesis of osteosarcoma remains unclear and despite use of chemotherapy drugs, resistance to these drugs affects the success of treatment. The present study was conducted to investigate the effects of icariin (ICA) on osteosarcoma cell proliferation and to investigate the role of the Wnt/β-catenin signaling pathway in the inhibition process of ICA on osteosarcoma cell proliferation. Different concentrations of ICA were selected to treat the osteosarcoma cell line 143B for 24 h, and then the onset concentration of ICA when it inhibited the growth of osteosarcoma cancer cell line 143B was detected via an MTT assay. The effect of ICA on the apoptosis of colon cancer cell line 143B under this concentration was detected using a flow cytometer. RNA in osteosarcoma cell line 143B was extracted, followed by reverse transcription. The expression levels of related and apoptotic proteins in the Wnt/β-catenin signaling pathway using ICA were detected by semi-quantitative PCR and western blot analysis, respectively. The expression quantities of vascular endothelial growth factor (VEGF) and MMP-9 were detected by ELISA. MTT assay showed that ICA inhibited the growth of 143B when its concentration was 5 µM (p<0.01). Flow cytometry showed that the number of apoptotic cells after ICA treatment was significantly higher than that in control group (p<0.01). RNA in osteosarcoma cell line 143B was extracted, followed by reverse transcription. Semi-quantitative PCR and western blot analysis revealed that the expression levels of p-GSK3β, β-catenin, c-Myc and cyclin D1 in cells after ICA treatment were significantly downregulated (p<0.01), while the expression level of caspase-3 was significantly increased (p<0.01). ELISA showed that the expression quantities of VEGF and MMP-9 were significantly decreased (p<0.01). Thus, ICA can significantly inhibit osteosarcoma cell proliferation and promote osteosarcoma cell apoptosis, which may be realized by affecting the expression of the Wnt/β-catenin signaling pathway and blocking the expression of related proteins.

Ginseng polysaccharide serves as a potential radiosensitizer through inducing apoptosis and autophagy in the treatment of osteosarcoma

Recent studies have confirmed that the combined use of anti-cancer drugs with ionizing radiation (IR) could improve the sensitivity of osteosarcoma (OS) cells. Therefore, it is necessary to identify potential effective drugs for the enhancement of IR-radiosensitivity. In the current study, we found that 20, 10, 5, and 1 μM of ginseng polysaccharide (GPS) significantly suppressed MG-63 cell viability with or without γ-ray radiation in a dose- and time-dependent manner. Strikingly, 20 μM of GPS combined with 5 Gy treatment suppressed colony formation capacity by nearly 13.75∼fold compared with IR treatment alone. Our results showed that GPS could markedly induce early apoptosis and autophagy in MG-63 cells. A higher drug concentration and a greater exposure dose were directly associated with more apoptosis and autophagy in cells. Western blot analysis showed that GPS decreased the phosphorylation of p38 and AKT as well as the protein expression of Bax and cleaved-caspase3. In summary, GPS inhibited proliferation and increased apoptosis and autophagic death in OS cells, indicating that GPS may be a potential effective auxiliary drug for improving the IR sensitivity of OS patients.