Abstract SY20-03: Nuclear-mitochondrial cross-talk: A key determinant of cancer metastasis

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Despite the well known energy requirements and stresses of metastasis, the relationships between metabolism, mitochondrial genetics and metastasis are still underdeveloped. Two lines of investigation point to more intimate involvement of mtDNA than is widely appreciated. First, recent data demonstrate that the metastasis suppressor KISS1 essentially reverses the so-called Warburg Effect by regulating mitochondrial biogenesis. KISS1 re-expression results in higher pH[Ex] due to reduced lactate secretion concomitant with reduced glycolysis and a shift toward oxidative phosphorylation. KISS1-expressing cells have 30-50% more mitochondrial mass, which appears to be due to higher expression of PPARγ co-activator 1α (PGC1α), a master regulator of mitochondrial biogenesis. shRNA-mediated knockdown of KISS1 and PGC1α establish a pathway between these molecules, mitochondrial biogenesis and metastatic potential. Second, genetic crosses with a newly described MNX (mitochondrial-nuclear exchange) mice suggest that mitochondrial polymorphisms (haplotypes) may control susceptibility to metastasis. Transgenic FVB/N-tg:MMTV-PyMT which spontaneously develop mammary tumors and lung metastasis with high penetrance were crossed with female MNX mice having the same nuclear background (FVB - wild-type) but with C57BL/6 and BALB/c mitochondrial backgrounds. Using this strategy, the mtDNA contributions to metastasis can be discriminated. Results demonstrate that tumor and metastasis incidence do not appear to be significantly different. However, metastasis size is greatly affected. Taken together, these data strongly support the concept that mitochondrial-nuclear cross-talk is a more significant determinant of metastasis than generally appreciated. SUPPORT: NCI-CA134981; Natl Fndn Cancer Res, Susan G. Komen SAC11037, Hall Family Fndn, KS Bioscience Auth. Citation Format: Danny R. Welch, Wen Liu, Kyle P. Feeley, Scott W. Ballinger. Nuclear-mitochondrial cross-talk: A key determinant of cancer metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr SY20-03. doi:10.1158/1538-7445.AM2014-SY20-03