Erratum: Retracted: Phosphotyrosine picked threonine kinase stimulates proliferation of human osteosarcoma cells in vitro and in vivo.

[This corrects the article DOI: 10.5114/aoms/115135.].

Phosphotyrosine picked threonine kinase stimulates proliferation of human osteosarcoma cells in vitro and in vivo.

Introduction: Osteosarcoma (OS) is the most common primary bone tumor, and the main affected population is adolescents. The survival of OS patients was 10-20% when surgery was used as a single treatment. There is less basic research on OS than other tumors, and we need more ways to improve the survival rate. Phosphotyrosine picked threonine kinase (TTK) has been widely reported as an oncogene in multiple types of cancers, and it is also known as a clinical therapeutic target. This study aims to assess TTK expression levels in human OS tissues and its link with the clinical characteristics of OS patients, and to evaluate the potential role in OS development. Material and methods: Immunohistochemical (IHC) assays were conducted to detect the expression levels of TTK in a total of 74 OS tissues and the corresponding adjacent tissues. Furthermore, according to the staining intensity of TTK in tumor tissues, patients were divided into TTK high and low expression groups. The possible correlation between TTK expression levels and clinical features were analyzed, and the effects of TTK on OS cell proliferation were detected through colony formation and cell counting kit-8 (CCK8) assays. The effects of TTK on tumor growth were detected using an animal model. Results: Phosphotyrosine picked threonine kinase was abnormally highly expressed in human OS tissues. Meanwhile, TTK was significantly correlated with the clinical characteristics such as tumor size (p = 0.004*) and clinical stage (p = 0.014*) of OS patients. Our results also revealed that the inhibition of TTK dramatically suppressed the proliferation of OS cells in vitro and blocked tumor growth in mice. Conclusions: We demonstrated the involvement of TTK in the development of OS, and therefore we suggest that TTK should be considered as a promising therapy target for OS.

Identification of Kinesin Family Member 2A (KIF2A) as a Promising Therapeutic Target for Osteosarcoma.

BACKGROUND: Osteosarcoma is known as a type of common human bone malignancy, and more therapeutic targets are still required to combat this disease. In recent years, the involvement of KIF2A in cancer progression has been widely revealed; however, its potential effect on osteosarcoma development remains unknown. This study is to assess the KIF2A expression levels in human osteosarcoma tissues and explore its potential role in osteosarcoma development. METHODS: Immunohistochemical (IHC) assays were conducted to evaluate the expression levels of KIF2A in a total of 74 samples of osteosarcoma tissues and adjacent nontumor tissues. According to the staining intensity in tumor tissues, patients were divided into highly expressed and low expression KIF2A groups. The possible links between the KIF2A expression and the clinical pathological features were explored and analyzed, and the effects of KIF2A on osteosarcoma cell proliferation, migration, and invasion were detected through colony formation assay, MTT assay, wound closure assay, and transwell assay, respectively. The effects of KIF2A on tumor growth and metastasis were detected by the use of animal models. RESULTS: KIF2A was highly expressed in human osteosarcoma tissues. Meanwhile, KIF2A was obviously correlated to the tumor size (P = 0.001∗) and clinical stage (P = 0.014∗) of osteosarcoma patients. Our results also revealed that the ablation of KIF2A dramatically blocked the proliferation, migration, and invasion capacity of osteosarcoma cells in vitro and blocked tumor growth and metastasis in mice. CONCLUSIONS: We investigated the involvement of KIF2A in the development and metastasis of osteosarcoma and therefore thought KIF2A as a promising therapeutic target for osteosarcoma treatment.

Identification of Lysosome-Associated Protein Transmembrane-4 as a Novel Therapeutic Target for Osteosarcoma Treatment.

OBJECTIVE: The aim of the study is to evaluate the expression of lysosome-associated protein transmembrane-4 (LAPTM4B) in human osteosarcoma tissue samples collected in our hospital, and to explore the possible correlations between the clinical pathological features of osteosarcoma patients and LAPTM4B expression. METHODS: Immunohistochemical (IHC) assays were performed to detect the expression levels of LAPTM4B in 62 tissue samples of osteosarcoma tissues and corresponding non-tumor tissues. According to LAPTM4B staining intensity in tumor tissues, osteosarcoma patients were classified into LAPTM4B high expression and low expression groups. In addition, the potential correlations between LAPTM4B expression levels and clinical pathological features were evaluated. In addition, we detected the effects of LAPTM4B on the proliferation and invasion of esteosarcoma cells through colony formation assay and transwell assay, respectively. We further explored the potential effects of LAPTM4B on tumor growth and metastasis using in vivo animal model. RESULTS: We revealed that LAPTM4B was highly expressed in human osteosarcoma tissues. We determined the significance between LAPTM4B and clinical features, including the tumor size (P = 0.004*) and the clinical stage (P = 0.035*) of osteosarcoma patients. Our results further demonstrated that ablation of LAPTM4B obviously blocked the proliferation and invasion of osteosarcoma cells in vitro and restrained tumor growth and metastasis in mice. CONCLUSION: We investigated the potential involvement of LAPTM4B in osteosarcoma progression and confirmed LAPTM4B as a novel therapeutic target for osteosarcoma.