OVA66, a tumor associated protein, induces oncogenic transformation of NIH3T3 cells
Authors: Huizhen Zhang
Renfeng Zhang
Feifei Song
Yong Zhang
Guohua Xie
Lisong Shen
Hailiang Ge
Qinqin Yin
Shujun Wang
Wei Rao
Ying Wang
Journal: PloS one (2014)
Discipline: Multidisciplinary
Keywords: tumor associated antigen; OVA66; oncogenic character; NIH3T3; cell cycling
Affiliations: Shanghai Institute of Immunology, Shanghai Jiaotong University (SJTU) School of Medicine, Shanghai, China., Department of Clinical Laboratory, Xinhua Hospital, Shanghai Jiaotong University (SJTU) School of Medicine, Shanghai, China.

Abstract:  The tumor associated antigen OVA66 has been demonstrated to be highly expressed in malignant tumors and implicated in various cellular processes. To further elucidate its oncogenic character, we established an OVA66 stably overexpressed NIH3T3 cell line and a vector transfected control, named NIH3T3-flagOVA66 and NIH3T3-mock, respectively. NIH3T3-flagOVA66 cells showed faster cell cycling, proliferation, cell migration and more resistance to 5-fluorouracil-induced apoptosis. When NIH3T3-flagOVA66 and NIH3T3-mock cells were injected into nude mice for xenograft tumorigenicity assays, the NIH3T3-flagOVA66 cells formed tumors whereas no tumors were observed in mice inoculated with NIH3T3-mock cells. Analysis of PI3K/AKT and ERK1/2 MAPK signaling pathways by serum stimulation indicated hyperactivation of AKT and ERK1/2 in NIH3T3-flagOVA66 cells compared with NIH3T3-mock cells, while a decreased level of p-AKT and p-ERK1/2 were observed in OVA66 knocked down HeLa cells. To further validate if the p-AKT or p-ERK1/2 is essential for OVA66 induced oncogenic transformation, we treated the cells with the PI3K/AKT specific inhibitor LY294002 and the ERK1/2 MAPK specific inhibitor PD98059 and found either inhibitor can attenuate the cell colony forming ability in soft agar and the cell viability of NIH3T3-flagOVA66 cells, suggesting aberrantly activated AKT and ERK1/2 signaling be indispensible of the tumorigenic role of OVA66. Our results indicate that OVA66 is important in oncogenic transformation, promoting proliferation, cell migration and reducing apoptosis via hyperactivating PI3K/AKT and ERK1/2 MAPK signaling pathway. Thus, OVA66 might be a novel target for early detection, prevention and treatment of tumors in the future. 

Retracted: No

PubPeer comments:
 Figure 3B shows two different cells, with four panels each. It was not clear what each of the different panels represented but based on the panel next to it, multiple replicates were performed. Yet some of the panels appear to show an overlap. Could the authors please clarify? ![file] , 
 Figure 5 shows mice bearing tumors. These tumors appear to be very large. ![file] Looking at the diagram below the photos, some of the tumor volumes were between 3-4 cubic centimeters. The Methods state that:  *The animal experiment protocol was reviewed and approved by the China Institutional Ethics Review Committee for Animal Experimentation. * . There is no approval number or apparent institutional review board listed. Could the authors please clarify what the maximum tumor volume measured on some of these animals was, and what the maximum size of tumor is according to the Animal Ethics Committee? ,