9P - Knockdown of MFN2 gene expression inhibits lung adenocarcinoma cell proliferation

Date 07 May 2017
Event ELCC 2017
Session Poster Display Session
Topics Lung and other Thoracic Tumours
Pathology/Molecular Biology
Presenter Yuqing Lou
Citation Annals of Oncology (2017) 28 (suppl_2): ii1-ii5. 10.1093/annonc/mdx090
Authors Y. Lou, Y. Zhang, J. Xu, P. Gu, W. Zhang, X. Zhang, H. Zhong, L. Jiang, B. Han
  • Department Of Pulmonary, Shanghai Chest Hospital, 200030 - Shanghai/CN

Abstract

Background

Mitofusin-2(MFN2) was initially identified as a hyperplasia suppressor in hyper-proliferative vascular smooth muscle cells of hypertensive rat arteries, which has also been implicated in various cancers. There exists a controversy in whether it is an oncogene or exerting anti-proliferative effect on tumor cells. Our previous cell cycle analysis and MTT assay showed that cell proliferation was inhibited in MFN2 deficient A549 human lung adenocarcinoma cells. MFN2-knockdown induced gene expression changes in A549 cells was analyzed by microarray assay and then functional pathway enrichment analysis revealed that six pathways were enriched in deregulated genes including Cell cycle, DNA replication, ECM-receptor interaction, Focal adhesion, MAPK signaling pathway and Chemokine signaling pathway, as we previously reported.

Methods

MFN2 expression at protein level was examined in 30 pair lung adenocarcinoma/adjacent normal lung samples with immunohistochemistry staining. Then MFN2 knockdown was performed in human lung adenocarcinoma cells A549 with lentiviral-mediated shRNA strategy. The expression changes of downstream factors were determined in A549 cells by western blot. Furthermore, tumor models in nude mice were generated and tumor formation and progression in these mice were analysed.

Results

As compared to adjacent normal lung tissues, MFN2 expression was significantly higher in lung adenocarcinoma tissues with positive MFN2 signals in 90% (27/30) lung adenocarcinoma tissues and only in 26.7% (8/30) adjacent normal tissues. The downregulation of RAP1A and upregulation of RALB and ITGA2 identified in MFN2-knockdown cells by microarray analysis were confirmed by western blot. In vivo, tumor models in nude mice were generated. Tumor formation and progression in nude mice suggested that MFN2 knockdown reduced tumorigenesis of A549 cells.

Conclusions

The current study confirmed the anti-proliferative effect of MFN2 deficiency and its risk in lung adenocarcinoma.

Clinical trial identification

Legal entity responsible for the study

Shanghai Chest Hospital

Funding

This work was supported by the National Natural Science foundation of China (81572249 and 81201839).

Disclosure

All authors have declared no conflicts of interest.