Comment on Xu XW et al.: Prognostic significance of VEGF expression in osteosarcoma: a meta-analysis

Correlation of vascular endothelial growth factor with survival and pathological characteristics of patients with osteosarcoma: A systematic review and meta-analysis

OBJECTIVE

This study aimed to assess the prognostic role of vascular endothelial growth factor (VEGF) expression in osteosarcoma.

METHODS

Systematic searches of PubMed, Embase, CINAHL, Cochrane Library, ScienceDirect, and Web of Science were conducted. The correlation between VEGF expression and patients' survival was our primary endpoint. The secondary endpoints were the associations between VEGF level and patients' sociodemographic and pathological characteristics. The pooled hazard ratio (HR) or odd ratio (OR) and corresponding 95% confidence intervals (CIs) were obtained to assess the associations between VEGF expression and the target factors. Subgroup and meta-regression analyses were conducted to explore potential factors that associated with VEGF efficacy.

RESULTS

The combined HR suggested that a positive VEGF status has a negative impact on overall survival (OS) (HR = 2.58; 95% CI, 2.09-3.19; P < 0.0001) and disease-free survival (DFS) (HR = 2.54; 95% CI, 1.84-3.50; P < 0.0001) in patients with osteosarcoma. Meta-regression analysis ruled out the influence of cut-off value, disease stage, histological subtype, disease grade, tumour location, geographic area, publication year, and method of HR acquisition on heterogeneity. Results showed that VEGF expression was closely correlated with tumour staging, chemotherapy response, and metastasis.

CONCLUSION

Based on the study results, VEGF could serve as an effective biomarker of prognosis in patients with osteosarcoma. Besides, VEGF was related to increased tumour malignancy, which might help guide clinical decision-making regarding therapy and outcomes.

MicroRNA-638 expression change in osteosarcoma patients via PLD1 and VEGF expression

The present study aimed to investigate the function and mechanism of microRNA-638 (miR-638) in osteosarcoma. MiR-638 expression change in patients with osteosarcoma was detected by reverse transcription-quantitative polymerase chain reaction. Expression of miR-638 was observed to be downregulated in patients with osteosarcoma compared with the control group. In vitro, overexpression of miR-638 induced apoptosis, and inhibited cell proliferation and invasion of osteosarcoma cells. Overexpression of miR-638 induced Bcl-2 associated X and caspase-3 protein expression, and suppressed cyclin D1, phospholipase D1 (PLD1) and vascular endothelial growth factor (VEGF) protein expression in osteosarcoma. The promotion of PLD1 decreased the effects of miR-638 on osteosarcoma cell proliferation. In summary, it was demonstrated that miRNA-638 expression change in patients with osteosarcoma and an in vitro model via PLD1 and VEGF expression and miRNA-638 may be potential clinical indicators of osteosarcoma.

Expression profile of Twist, vascular endothelial growth factor and CD34 in patients with different phases of osteosarcoma

The aim of the present study was to investigate the clinical significance of Twist, vascular endothelial growth factor (VEGF) and CD34 expression in osteosarcoma (OS) in order to elucidate potential therapeutic targets for the treatment of OS. Immunohistochemistry was performed to detect the protein expression of Twist, VEGF and CD34 in OS and osteochondroma (OC) tissues. The ratio of the protein expression of Twist and VEGF in OS and OC tissues as well as at different phases of OS was compared using chi-squared tests. Microvessel density (MVD), as determined by CD34 labeling, in OS and OC tissue as well as at different phases of OS was compared using the Student's t-test. In addition, associations between Twist, VEGF and MVD were assessed using the Spearman's rank correlation test. The results revealed that out of the 32 OS tissues examined, 56.25% exhibited Twist positive expression, 71.88% exhibited VEGF positive expression and the MVD was increased compared with that of the OC tissue. The positive rate of Twist and VEGF expression in phase III OS tissues was significantly increased compared with that in phase I/II OS tissues (Twist: χ²=5.732, P=0.018; VEGF: χ²=7.513, P=0.006). The MVD in phase III OS tissues (31.08±3.36 per field) was significantly higher compared with that of the phase I/II OS tissues (41.2±4.17 per field; t=7.536, P<0.001). Spearman's rank correlation analysis revealed that Twist expression was positively associated with VEGF expression (r=0.371, P=0.002) and with MVD (r=0.393, P=0.001) in OS; in addition, VEGF expression was found to have a positive correlation with MVD (r=0.469, P=0.001). In conclusion, the results of the present study demonstrated that OS tissues exhibited elevated Twist and VEGF expression as well as MVD compared with OC tissue. In addition, metastatic OS (phase III) exhibited an increased positive rate of Twist and VEGF expression as well as MVD values compared with non-metastatic OS (phase I/II). Furthermore associations were detected between Twist and VEGF expression as well as VEGF and MVD. Therefore, inhibition of Twist expression may have potential therapeutic use for the treatment of OS.