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.
Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Headington, United Kingdom.
Houman
H
Ashrafian
Linda
L
O'Flaherty
Julie
J
Adam
Violetta
V
Steeples
Yuen-Li
YL
Chung
Phil
P
East
Sakari
S
Vanharanta
Heli
H
Lehtonen
Emma
E
Nye
Emine
E
Hatipoglu
Melroy
M
Miranda
Kimberley
K
Howarth
Deepa
D
Shukla
Helen
H
Troy
John
J
Griffiths
Bradley
B
Spencer-Dene
Mohammed
M
Yusuf
Emanuela
E
Volpi
Patrick H
PH
Maxwell
Gordon
G
Stamp
Richard
R
Poulsom
Christopher W
CW
Pugh
Barbara
B
Costa
Chiara
C
Bardella
Maria Flavia
MF
Di Renzo
Michael I
MI
Kotlikoff
Virpi
V
Launonen
Lauri
L
Aaltonen
Mona
M
El-Bahrawy
Ian
I
Tomlinson
Patrick J
PJ
Pollard
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