Epithelial-mesenchymal transition (EMT) plays an important role in
cancer invasion and
metastasis by enabling
cancer cells to depart from the primary
tumor, invade surrounding tissue and disseminate to distant organs. The existence and function of EMT in
cervical cancer is poorly understood. Placental
growth factor (PLGF) has been shown to associate with EMT in various
cancers. However, whether PLGF is involved in EMT in
cervical cancer remains unclear. Thus the present study examined the relationship between PLGF expression and EMT-related
proteins in 110 cervical lesions samples. We detected that PLGF was expressed in 61.8% cervical lesion sections. In addition, PLGF expression is positively correlated with low expression level of
E-cadherin and high expression level of
vimentin. Serum samples and cervical lavage samples were collected from patients with pre-invasive and invasive lesion of uterine cervix or normal control group, the PLGF levels were determined by
enzyme-linked
immunosorbent assay (ELISA). We found that a significantly high level of PLGF could be detected both in serum and vaginal lavage compared with normal women group, and there is no significant difference between serum and lavage in PLGF level. In addition, whatever in lavage or in serum, the PLGF level in stage I and II was significantly higher than it in CINIII or
cancer in situ. However, there is no significant difference between the stage I and stage II; we also found that exogenous PLGF promotes molecular changes of epithelial-mesenchymal transition (EMT) in siha cells. In addition, application of a specific EKR1/2 inhibitor could reverse the effects of PLGF. These findings suggested that PLGF could regulate the expression of EMT-related
proteins and promote migration of siha cells through ERK/MAPK signaling pathway.
Therapies that targets PLGF/Flt-1/ERK/MAPK signaling pathway may be beneficial in treatment of
cervical cancer.