Establishment and characteristics of two syngeneic human osteosarcoma cell lines from primary tumor and skip metastases

Aim： To characterize and compare the different biological behaviors of 2 novel human osteosarcoma cell lines, Zos and Zos-M, established respectively from the primary tumor and the skip metastasis of an osteosarcoma patient. Methods： In vitro studies included morphological observations, karyotype analysis, 3-（4,5- dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide cell proliferation assay, and cell sensitivity to chemotherapeutic drugs. Subcutaneous and intravenous inoculations into nude mice were carried out to study the tumorigenicity and the metastatic potential. RT-PCR was performed to assess the expression of the osteoblastic markers and some metastasis-related genes. Results： Both cell lines remained stable for more than 100 passages in vitro without interruption. The RT- PCR examination indicated that they retained the molecular characteristics of an osteoblastic lineage. The karyotype analysis displayed aneuploidy and various structural abnormalities. Both cell lines are tumorigenic; Zos-M differs from Zos by the former＇s ability to develop lung metastasis after intravenous injection. The comparison of the expression patterns of some metastasis-related genes revealed that the decreased expression of cadherin-11 in Zos-M may correlate with a high potential of metastases. Moreover, both cell lines are less sensitive to the current chemotherapy protocols. Conclusion： The establishment of osteosarcoma cell lines, Zos and Zos-M, and related animal models provide a useful resource for studying the aggressive behavior of osteosarcoma and will be helpful for screening effective treatment strategies.