Jie Zhang

Background: Head and neck fibrosarcoma is a rare malignant tumor, accounting for about 1% of all head and neck tumors. It can also occur in the jaw bone, for which surgical resection is the main treatment but the recurrence rate is high and the prognosis is usually poor. Due to the lack of models mimicking the biological characteristics of the tumor, there is little progress in the research of the pathogenesis and treatment of fibrosarcoma. Therefore, there is an urgent need to explore a high-fidelity model that can reflect the biological characteristics of fibrosarcoma for the sake of improving the therapeutic outcome and prognosis, and preventing recurrence. Patient-derived xenografts (PDX) may more accurately reflect the human disease, and is an attractive platform to study disease biology and develop treatments and biomarkers. In this study we describe the establishment of jaw fibrosarcoma PDX models and compare PDX tumors to those of human origin. Methods: Tumor biopsies from a patient with jaw fibrosarcoma were implanted in immunodeficient mice. Primary and PDX tumors were characterized extensively by histology, immunohistochemistry and humanized identification. Based on the finding of our previous preliminary research that plumbagin had an anti-tumor effect against head and neck cancer, we used this model in the present study to evaluate the anti-tumor effect of plumbagin on jaw fibrosarcoma. Results: The established PDX model maintained the histological and immunohistochemical characteristics of the primary tumor. Plumbagin significantly inhibited the tumor growth in the jaw fibrosarcoma PDX model. Conclusion: We successfully established a PDX model of jaw fibrosarcoma and demonstrated that this PDX model preserved the important molecular characteristics of the human primary tumor, thus providing a powerful tool for treatment research and new drug development of jaw fibrosarcoma. In addition, plumbagin was found to have an inhibitory effect on the growth of PDX modeled jaw fibrosarcoma, which provides a preliminary research basis for its clinical application.

Melanoma is an invasive and malignant type of tumor with unsatisfactory therapeutic outcomes. The present study aimed to detect the expression levels of microRNA (miR)‑125b in formalin‑fixed paraffin‑embedded (FFPE) melanoma tissues and the association of its expression levels with the clinical features, diagnosis and prognosis of melanoma. Expression levels of miR‑125b in 29 FFPE melanoma specimens (16 primary and 13 metastatic tumors), and 16 intradermal nevus (IDN) specimens as a control, were detected by reverse transcription‑quantitative PCR. Associations among miR‑125b expression and mortality, patient age and sex, tumor location and size, lymph node metastasis (LNM) and TNM stage were analyzed by t‑test. The diagnostic value of miR‑125b for melanoma was evaluated by receiver operating characteristic (ROC) curve analysis. Prognosis of patients in the microRNA‑125b low‑ and high‑expression groups was analyzed by Fisher's exact test. The association between miR‑125b expression and the overall survival of patients with melanoma was assessed using Kaplan‑Meier curve analysis and a Cox proportional hazards model. The results revealed that the expression levels of miR‑125b in primary and metastatic melanomas were significantly lower than those in the IDN control group (P<0.05), and the expression levels of miR‑125b in the metastatic group were significantly lower than those in the primary group (P0.05). ROC curve analysis revealed that the area under the curve (AUC) was 0.880, with a 95% CI of 0.777‑0.984 (P<0.05). The overall survival rate of the patients with a low expression level of miR‑125b (20.0%) was lower than that of patients with a high expression level of miR‑125b (64.3%) (P<0.05). miR‑125b expression was an independent predictor of overall survival in patients with melanoma [hazard ratio (HR), 0.252; 95% CI, 0.087‑0.729]. Overall, these findings indicated that a low expression level of miR‑125b was associated with higher LNM and TNM stage in patients with melanoma, and that this has a certain diagnostic value. miR‑125b may be used for the early screening of melanoma and determining the prognosis of patients with melanoma, and may be a potential target for the treatment of the disease.