Abstract: Abstract: Objective: To study the influence of the local tumor microenvironments on LPPCN formation(linearly patterned programmed cell necrosis, LPPCN). Methods: The left femoral arteries of 9 C57BL mice were ligated and then B16F10 melanoma cells suspension was injected into the left ischemic skeletal muscles and non- ischemic right controls respectively to build the ischemic animal model; Biomechanical animal model was built by injecting the B16F10 melanoma cells suspension into the the abdominal cavity and left skeletal muscles of 10 C57BL mice.HE staining was performed to compare the LPPCN distribution among groups.Immunohistochemistry was employed to detect the expression of matrix metalloproteinase-2 & 9 .Results: The LPPCN cell numbers in the ischemic group were significantly higher than those in the control group （P<0.01）； and the skeletal muscle group significantly higher than those in the abdominal cavity group（P<0.01）.Similarly,the expression of MMP-2 and MMP-9 was higher in the ischemic group than that in the control group （P<0.01）and the skeletal muscle group significantly higher than those in the abdominal cavity group（P<0.01）.Conclusion:Hypoxia and microenvironment pressure of tumor can increase MMP-2, MMP-9 expression and influence the LPPCN formation.

Key words: Melanoma, LPPCN, Animal model, Hypoxia, Tumor angiogenesis