Effects of proline-rich tyrosine kinase 2 on growth and hematogenous metastasis of human colorectal cancer cells

Abstract

Objective To investigate the effects of the proline-rich tyrosine kinase 2 (Pyk2) on the growth and the hematogenous metastasis of the human colorectal cancer SW480 cells. Methods SW480 cells were stably transfected with empty vector (pcDNA4-A),vector containing Pyk2 + or Pyk2-,respectively.Cells from each group (SW480-Pyk2 +,SW480,SW480-vector and SW480-Pyk2- cells)were inoculated subcutaneously into 8 nude mice (BALB/C nu/nu) respectively.Six weeks later,the subcutaneous tumors were harvested and weighed.Lungs were harvested 6 weeks after nude mice lung metastasis model was constructed.Then the lung metastatic amounts were counted by microscopy.Results The mass of the subcutaneous tumors in SW480-Pyk2 + group (Mean Rank =6.19) was less than other groups ( SW480 18.69,SW480-vector 14.12),and that in SW480-Pyk2 - group ( Mean Rank =27.00) was more than other groups (X2 =20.646,P ＜ 0.05 ).The lung metastatic amounts in SW480-Pyk2 + group ( Mean Rank =6.62) were the least,those in SW480-Pyk2- group ( Mean Rank =28.38) were the most,and those in the remaining two groups ( SW480 16.06,SW480-vector 14.94) were moderate (X2 =21.948,P ＜ 0.05).The expression of Pyk2 was highly negatively correlated with the mass of the tumors and lung metastatic amounts (r =-0.776,- 0.777,P ＜ 0.05 ).Conclusion Pyk2 could inhibit the growth and the lung metastasis of SW480 cells in vivoin nude mice. Key words: Colorectal neoplasms; Proline-rich tyrosine kinase 2; Hematogenous metastasis