Expression Of STAT3, MMP-1and TIMP-1in Gastric Cancer Tissues And Correlation With Pathological Features

Aim: To investigate the mRNA and protein expression of STAT3, MMP-1andTIMP-1in gastric cancer (GC) tissues, and to explore the correlation between thesegenes and the biological behaviors of GC.Methods: Semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR) was employed to detected the mRNA expression of STAT3, MMP-1andTIMP-1in GC tissues (n=30), adjacent non-tumor tissues (n=30) and superficialgastritis (SG) tissues (n=30). Immunohistochemistry was performed using SP methodto detect the protein expression of Stat3(unphosphorylated), MMP-1and TIMP-1inthese tissues. The correlation between the pathological features of GC and theexpression of STAT3, MMP-1as well as TIMP-1, was evaluated.Results: The mRNA expression of STAT3in GC, adjacent non-tumor and SGtissues were0.821±0.128,0.355±0.100and0.398±0.096, respectively. Comparedwith expression level in other tissues, that in GC tissues was significantly higher(P<0.05). The mRNA expression of MMP-1in GC, adjacent non-tumor and SGtissues were0.749±0.133,0.335±0.106and0.345±0.063, respectively. Comparedwith expression level in other tissues, that in GC tissues was significantly increased(P<0.05). The mRNA expression of TIMP-1in GC tissues (0.386±0.125) wascomparable to that in adjacent non-tumor tissues (0.343±0.078) and SG tissues(0.345±0.061)(P>0.05), but the mRNA expression of TIMP-1in GC tissues wassignificantly correlated with the differentiation of GC cells and lymph nodemetastasis. The mRNA expression of STAT3, MMP-1and TIMP-1was significantlyassociated with the differentiation of GC cells and lymph node metastasis, but notrelated to age, gender and tumor size. The positive rate of unphosphorylated Stat3expression in GC, adjacent normal and SG tissues were86.7%,16.7%and10.0%,respectively. Compared with positive rate in other tissues, that in GC tissues wasdramatically higher (P<0.05). The positive rate of MMP-1protein expression in GC,adjacent normal and SG tissues were63.3%,13.3%and16.7%, respectively.Compared with positive rate in other tissues, that in GC tissues was markedly higher (P<0.05). However, no significant difference was observed in the TIMP-1-positiverate among the three groups (23.3,16.7and10.0%, respectively; P>0.05).Conclusion: The mRNA and protein expression of STAT3and MMP-1in GCtissues were significantly higher than that in other tissues. The mRNA expression ofSTAT3, MMP-1and TIMP-1was related with the differentiation of GC cells andlymph node metastasis. It is implied that STAT3and MMP-1may be involved in thedevelopment and metastasis of GC, treatment targeting TIMP-1may be a promisingstrategy.