The attached file includes the 6 different supplementary tables as described below Supplementary Table 1: Clinicopathologic characteristics of 100 patients with invasive breast cancer Supplementary Table 2: Interacting proteins of LMW-E(T1) identified from RePCA screen Supplementary Table 3: Doubling time (hrs.) of 76NE6 TDCs+KD ACLY Supplementary Table 4: ACLY inhibition delays tumor formation Supplementary Table 5: Adipophilin, Ki-67 and LMW-E immuno- expression in xenograft tumors Supplementary Table 6 : Adipophilin scoring system
ARTICLE ABSTRACT
Cyclin E is altered in nearly a third of invasive breast cancers where it is a powerful independent predictor of survival in women with stage I–III disease. Full-length cyclin E is posttranslationally cleaved into low molecular weight (LMW-E) isoforms, which are tumor-specific and accumulate in the cytoplasm because they lack a nuclear localization sequence. We hypothesized that aberrant localization of cytosolic LMW-E isoforms alters target binding and activation ultimately contributing to LMW-E–induced tumorigenicity. To address this hypothesis, we used a retrovirus-based protein complementation assay to find LMW-E binding proteins in breast cancer, identifying ATP-citrate lyase (ACLY), an enzyme in the de novo lipogenesis pathway, as a novel LMW-E–interacting protein in the cytoplasm. LMW-E upregulated ACLY enzymatic activity, subsequently increasing lipid droplet formation, thereby providing cells with essential building blocks to support growth. ACLY was also required for LMW-E–mediated transformation, migration, and invasion of breast cancer cells in vitro along with tumor growth in vivo. In clinical specimens of breast cancer, the absence of LMW-E and low expression of adipophilin (PLIN2), a marker of lipid droplet formation, associated with favorable prognosis, whereas overexpression of both proteins correlated with a markedly worse prognosis. Taken together, our findings establish a novel relationship between LMW-E isoforms of cyclin E and aberrant lipid metabolism pathways in breast cancer tumorigenesis, warranting further investigation in additional malignancies exhibiting their expression. Cancer Res; 76(8); 2406–18. ©2016 AACR.
