Mutations of the von Hippel-Lindau gene confer increased susceptibility to natural killer cells of clear-cell renal cell carcinoma.
The tumor suppressor gene von Hippel-Lindau (VHL) is involved in the development of sporadic clear-cell renal cell carcinoma (RCC). VHL interferes with angiogenesis and also controls cell adhesion and invasion. Therapies that target VHL-controlled genes are currently being evaluated in RCC patients. RCC is a immunogenic tumor and treatment with interleukin-2 (IL2) or interferon (IFN)-α results in regression in some patients. We used two renal tumor cell lines (RCC6 and RCC4) carrying VHL loss-of-function mutations to investigate the role of mutant VHL in susceptibility to natural killer (NK) cell-mediated lysis. The RCC6 and RCC4 cell lines were transfected with the wild-type gene to restore the function of VHL. The presence of the gene in RCC cells downregulated hypoxia-inducible factor (HIF)-1α and subsequently decreased vascular endothelial growth factor (VEGF) production. Relative to control transfectants and parental cells, pVHL-transfected cell lines activated resting and IL2-activated NK cells less strongly, as assessed by IFNγ secretion, NK degranulation and cell lysis. NKG2A, a human leukocyte antigen (HLA)-I-specific inhibitory NK receptor, controls the lysis of tumor targets. We show that HLA-I expression in RCC-pVHL cells is stronger than that in parental and controls cells, although the expression of activating receptor NK ligands remains unchanged. Blocking NKG2A/HLA-I interactions substantially increased lysis of RCC-pVHL, but had little effect on the lysis of VHL-mutated RCC cell lines. In addition, in response to IFNα, the exponential growth of RCC-pVHL was inhibited more than that of RCC-pE cells, indicating that VHL mutations may be involved in IFNα resistance. These results indicate that a decreased expression of HLA-I molecules in mutated VHL renal tumor cells sensitizes them to NK-mediated lysis. These results suggest that combined immunotherapy with anti-angiogenic drugs may be beneficial for patients with mutated VHL.
Institut Cochin, INSERM U1016, CNRS UMR 8104, Université Paris Descartes, Paris, France.
A
A
Perier
G
G
Fregni
S
S
Wittnebel
S
S
Gad
M
M
Allard
N
N
Gervois
B
B
Escudier
B
B
Azzarone
A
A
Caignard
D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000276:immunology / Q000473:pathology; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003602:Cytotoxicity, Immunologic / Q000235:genetics* / Q000276:immunology; D005816:Genetic Complementation Test; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016898:Interferon-alpha / Q000494:pharmacology; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D007680:Kidney Neoplasms / Q000235:genetics / Q000276:immunology / Q000473:pathology; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D009154:Mutation; D055654:NK Cell Lectin-Like Receptor Subfamily C / Q000378:metabolism; D034622:RNA Interference; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000276:immunology / Q000378:metabolism; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000235:genetics* / Q000378:metabolism
C497442:HIF1A protein, human; D015395:Histocompatibility Antigens Class I; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D016898:Interferon-alpha; D055654:NK Cell Lectin-Like Receptor Subfamily C; D042461:Vascular Endothelial Growth Factor A; D007371:Interferon-gamma; D051794:Von Hippel-Lindau Tumor Suppressor Protein