CapG a putative oncogen is involved in invasiveness of breast cancer cells

Objective:

The aim of this work was to study the correlation between CapG-expression level and clinico-pathological parameter in breast cancer as well as functional characterization of CapG and analysis of CapG-transcriptome in mamma carcinoma cell lines to understand the pathogenic mechanism of CapG upregulation.

Material and Methods:

CapG expression level in breast cancer tissue of 78 patients was analyzed by qRT-PCR on an ALF-sequencer. For CapG-expression levels in MaCa-cell lines qPCR with relative quantification was used. Statistical significance was calculated using chi² test or fisher's test, respectively. CapG-knockdown was performed using siRNA and stable CapG-overexpression was achieved by retroviral vector based transfection. Determining invasiveness was performed using the BioCoat™Matrigel™ based invasion assay. Subcellular fractionation and increased CapG-protein level was analyzed by immunoblotting. Microarray was performed to study CapG-transcriptome and analyzed by gene ontology tools.

Results:

CapG-overexpression was detected in 28% of breast cancer tissues and significantly associates with metastasis-status (M1) and negative ER-status (both p ≤0,05). Invasiveness of MaCa-cell lines correlated with CapG-expression level and CapG knockdown or over-expression decrease or increase invasiveness, respectively. Moreover, CapG nuclear-localization was observed in high invasive MaCa-cell lines or after transfection. Analyzing CapG-transcriptome revealed new gene candidates, which might help to understand the role of CapG in the process of metastasis.

Conclusion:

CapG might be stated as an oncogene involved in invasiveness, regulate gene transcription and dissemination of breast cancer cells.