Extended Data Fig. 2: Assessment of glucose carbon fate in breast tumors growing in different tissue sites.
From: Fatty acid synthesis is required for breast cancer brain metastasis
a, Relative gamma-aminobutyric acid (GABA) levels were measured by liquid chromatography–mass spectrometry (LCMS) in BT474 tumors isolated from the brain or mammary fat pad (MFP) of Nude mice. Data are from the dataset presented in Fig. 1a and Supplementary Data 1. **P = 0.0038 by two-tailed t-test (Brain tumors, n = 7; MFP tumors n = 6; tumors from independent mice). b, Western blot analysis of acetyl-CoA carboxylase (ACC1), fatty acid synthase (FASN), and stearoyl-CoA desaturase-1 (SCD1) expression in MDAMB361 brain and MFP tumor tissue. β-actin expression was assessed as a loading control, and relative densitometry values (normalized to β-actin expression) were used for quantitation with values presented beneath each blot. Differences in protein expression between brain and MFP tumors was compared using a two-tailed t-test. c, The percent of fully labeled glucose (m + 6) in blood plasma following a 12 h 30 mg/kg/min 13C-glucose infusion into Nude female mice bearing BT474 lesions in the brain or in the MFP as assessed by gas chromatography–mass spectrometry (GCMS). **P = 0.0094 by two-tailed t-test. (Plasma from mice bearing BT474 brain tumors, n = 5; Plasma from mice bearing BT474 MFP tumors, n = 6). d-m, The distribution of 13C-labeling in the indicated metabolites as measured by GCMS from BT474 tumors in the brain and MFP, and from noncancerous brain and MFP adipose tissue (WAT) after a 12 h 30 mg/kg/min 13C-glucose infusion into Nude female mice. The data for each isotopologue presented was normalized to 13C-glucose labeling in plasma. (Brain tumors, n = 5; MFP tumors, n = 6; Cortex tissue, n = 12; WAT, n = 5). n,o, BT474 brain and MFP tumors were collected following a 12 h 30 mg/kg/min 13C-glucose infusion and saponified palmitate levels (n) and the distribution of 13C-label in even isotopologues of saponified palmitate (o) were assessed by GCMS. Palmitate levels were normalized to tissue weight and compared using a two-tailed t-test (n.s. denotes not significant). Each isotopologue was normalized to 13C-glucose labeling in plasma and to palmitate total ion counts. These data are from a separate experiment as that shown in Fig. 1e, and were collected to enable normalization based on palmitate total ion counts. (Brain Tumors, n = 3; MFP Tumors, n = 5). Data in panels a, and c–o represent means ± s.e.m.
