Expression profiling in progressive stages of fumarate-hydratase deficiency: the contribution of metabolic changes to tumorigenesis.
Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is caused by mutations in the Krebs cycle enzyme fumarate hydratase (FH). It has been proposed that "pseudohypoxic" stabilization of hypoxia-inducible factor-α (HIF-α) by fumarate accumulation contributes to tumorigenesis in HLRCC. We hypothesized that an additional direct consequence of FH deficiency is the establishment of a biosynthetic milieu. To investigate this hypothesis, we isolated primary mouse embryonic fibroblast (MEF) lines from Fh1-deficient mice. As predicted, these MEFs upregulated Hif-1α and HIF target genes directly as a result of FH deficiency. In addition, detailed metabolic assessment of these MEFs confirmed their dependence on glycolysis, and an elevated rate of lactate efflux, associated with the upregulation of glycolytic enzymes known to be associated with tumorigenesis. Correspondingly, Fh1-deficient benign murine renal cysts and an advanced human HLRCC-related renal cell carcinoma manifested a prominent and progressive increase in the expression of HIF-α target genes and in genes known to be relevant to tumorigenesis and metastasis. In accord with our hypothesis, in a variety of different FH-deficient tissues, including a novel murine model of Fh1-deficient smooth muscle, we show a striking and progressive upregulation of a tumorigenic metabolic profile, as manifested by increased PKM2 and LDHA protein. Based on the models assessed herein, we infer that that FH deficiency compels cells to adopt an early, reversible, and progressive protumorigenic metabolic milieu that is reminiscent of that driving the Warburg effect. Targets identified in these novel and diverse FH-deficient models represent excellent potential candidates for further mechanistic investigation and therapeutic metabolic manipulation in tumors.
Ashrafian
Houman
H
Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Headington, United Kingdom.
O'Flaherty
Linda
L
Adam
Julie
J
Steeples
Violetta
V
Chung
Yuen-Li
YL
East
Phil
P
Vanharanta
Sakari
S
Lehtonen
Heli
H
Nye
Emma
E
Hatipoglu
Emine
E
Miranda
Melroy
M
Howarth
Kimberley
K
Shukla
Deepa
D
Troy
Helen
H
Griffiths
John
J
Spencer-Dene
Bradley
B
Yusuf
Mohammed
M
Volpi
Emanuela
E
Maxwell
Patrick H
PH
Stamp
Gordon
G
Poulsom
Richard
R
Pugh
Christopher W
CW
Costa
Barbara
B
Bardella
Chiara
C
Di Renzo
Maria Flavia
MF
Kotlikoff
Michael I
MI
Launonen
Virpi
V
Aaltonen
Lauri
L
El-Bahrawy
Mona
M
Tomlinson
Ian
I
Pollard
Patrick J
PJ
D000818:Animals; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005649:Fumarate Hydratase / Q000172:deficiency* / Q000235:genetics*; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D006019:Glycolysis; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018231:Leiomyomatosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009130:Muscle, Smooth / Q000378:metabolism / Q000473:pathology; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D032681:Spectral Karyotyping
D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D005649:Fumarate Hydratase