Identification of the functional role of AF1Q in the progression of breast cancer.
A novel highly metastatic MDA-MB-231HM cells, derived from MDA-MB-231, was established in our institute. RT-PCR, real-time PCR and Western blot showed that AF1Q gene was differentially expressed between highly metastatic MDA-MB-231HM cells and its parental MDA-MB-231 cells. However, its molecular mechanisms in breast cancer metastasis remain to be characterized. To investigate the effects of AF1Q on the progression of human breast cancer cells, in the present study, recombinant expression plasmid vectors of the human AF1Q gene was transfected into MDA-MB-231 cells. We demonstrated that AF1Q overexpression enhanced the in vitro proliferation and invasive potential of breast cancer cells. Focused microarray analyses showed that 22 genes were differentially expressed between AF1Q transfected cells and its parental counterparts. Integrin alpha3, accompanied by up-regulation of Ets-1 and MMP-2, significantly enhanced the in vitro invasive potential of human breast cancer cells mediated by AF1Q. Estrogen-responsive ring finger protein gene (EFP), also played a role in the enhancement of in vitro proliferation of human breast cancer cells mediated by AF1Q, accompanied by down-regulation of 14-3-3delta. The association was ERalpha independent. These results were further demonstrated by RNA interference (RNAi) experiment in vitro. In in vivo study, we also demonstrated that AF1Q transfected breast cancer cells grew much faster and had more pulmonary metastases than vector-transfected or its parental counterparts. On the contrary, AF1Q knockdown cells grew slower and had less pulmonary metastasis. Similar effects of AF1Q on integrin alpha3, Ets-1, MMP-2, EFP, and 14-3-3delta expression observed in vitro studies were also found in the in vivo study. Taken together, these results provide functional evidences that overexpression of AF1Q leads to a more progression in human breast cancer, at least in part, through regulating the integrin alpha3, Ets-1, MMP-2, EFP, and 14-3-3delta expression.
Chang
Xin-Zhong
XZ
Department of Oncology, Breast Cancer Institute, Cancer Hospital, Shanghai Medical College, Institutes of Biomedical Science, Fudan University, Shanghai, 200032, P.R. China.
Li
Da-Qiang
DQ
Hou
Yi-Feng
YF
Wu
Jiong
J
Lu
Jin-Song
JS
Di
Gen-Hong
GH
Jin
Wei
W
Ou
Zhou-Luo
ZL
Shen
Zhen-Zhou
ZZ
Shao
Zhi-Ming
ZM
D000818:Animals; D001798:Blood Proteins / Q000235:genetics* / Q000378:metabolism*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018450:Disease Progression; D005260:Female; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011518:Proto-Oncogene Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D001798:Blood Proteins; C091736:MLLT11 protein, human; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins