Abstract:

Objective To study the expressions of matrix metalloproteinases-9(MMP-9) and proliferating cell nuclear antigen(PCNA) in telomerase and alternative lengthening of telomere osteosarcoma,and discuss the effects of MMP-9 and PCNA
 in the occurrence and development of osteosarcoma. Methods The expressions of MMP-9,PCNA,human telomerase reverse transcriptasc(hTERT) and promyelocytic leukemia body(PML) were examined using immunohistochemical SP staining method in 2
7 cases of osteosarcoma and 10 cases of normal bone tissues.Results  ①The positive rates of MMP-9 and PCNA expressions in osteosarcoma tissues were 88.89% and 85.19% respectively,in normal bone tissues were 10% and 0%,there were significant differences between two groups(P<0.001);② The expressions of MMP-9 in osteosarcoma of telomerase  were twelve cases of  (+++),five cases of  (++),one case of  (+),two cases of　(－).The expressions of MMP-9 in osteosarcoma of alternative lengthening of telomere were zero case of(+++),four cases of (++),two cases of (+),one case of (－),there were statistically significant differences between telomerase and telomere alternative osteosarcoma( P<0.05).③ The expressions of PCNA in osteosarcoma of telomerase were ten cases of  (+++),six cases of (++),one case of  (+),two cases of(－),the expressions of PCNA  in osteosarcoma of alternative lengthening of telomere were zero case of (+++),four cases of (++),two cases of (+),one case of (－),there were statistically significant differences between telomerase and telome
re alternative osteosarcoma( P<0.05).Conclusion There are statistically significant differences of the expressions of MMP-9 and PCNA between osteosarcoma of telomerase and telomere alternative osteosarcoma.The abilities of metastasis and invasion and  proliferation in telomerase osteosarcoma are stronger than those of  alternative lengthening of telomere osteosarcoma.

Key words: osteosarcoma;matrix metalloproteinases-9;proliferating cell nuclear antigen；telomerase； alternative lengthening of telomere