The role of the globular heads of C1q receptor (gC1qR) gene in regulating apoptosis of human cervical squamous cell carcinoma.

The globular heads of the human C1q receptor (gC1qR) are multi-compartmental and multi-functional cellular proteins. The list of biological responses mediated by the gC1qR includes growth perturbation and morphological abnormalities, along with the initiation of apoptosis. However, the effects of the gC1qR on the apoptosis of cervical squamous carcinoma cells (C33a and SiHa) have not been demonstrated. Here, human cervical tissues were examined for the expression of the gC1qR using real-time PCR and Western blot analysis. Apoptotic death of C33a and SiHa cells was assessed by flow cytometric analysis to detect the subG1 population. Viability, migration and proliferation of C33a and SiHa cells were detected via the water-soluble tetrazolium salt (WST-1) assay, the Transwell assay and the (3)H-thymidine incorporation into DNA assay ((3)H-TdR), respectively. These data showed that expression of the gC1qR protein was significantly decreased in human cervical squamous cell carcinoma tissues relative to normal cervix tissues. C33a and SiHa cells transfected with a GFP-gC1qR vector resulted in the up-regulation of cellular apoptosis and an apparent increase in the expression of the p38 mitogen-activated protein kinase (p38 MAPK). Further, the changes in C33a and SiHa cells viability, migration and proliferation observed upon overexpression of gC1qR could be abrogated using the p38 MAPK inhibitor SB202190. These data indicate that gC1qR inhibits viability, migration and proliferation of cervical squamous cells carcinoma via the p38 MAPK signalling pathway.