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The sonic hedgehog signaling pathway is reactivated in human renal cell carcinoma and plays orchestral role in tumor growth.

Dormoy V, Danilin S, Lindner V, Thomas L, Rothhut S, Coquard C, Helwig JJ, Jacqmin D, Lang H, Massfelder T - Mol. Cancer (2009)

Bottom Line: The sonic hedgehog (SHH) signaling pathway is crucial to normal development.Gli1, cyclin D1, Pax2, Lim1, VEGF, and TGF-beta were exclusively expressed in tumors and were shown to be regulated by SHH, as evidenced by immunoblot after SHH inhibition.Using specific inhibitors and immunoblot, the activation of the oncogenic PI3K/Akt, NF-kB and MAPK pathways was decreased by SHH inhibition.

View Article: PubMed Central - HTML - PubMed

Affiliation: INSERM U682, Section of Renal Cancer and Renal Physiopathology, University of Strasbourg, School of Medicine, Strasbourg, 67085 France. valerian.dormoy@medecine.u-strasbg.fr

ABSTRACT

Background: Human clear cell renal cell carcinoma (CRCC) remains resistant to therapies. Recent advances in Hypoxia Inducible Factors (HIF) molecular network led to targeted therapies, but unfortunately with only limited clinical significance. Elucidating the molecular processes involved in kidney tumorigenesis and resistance is central to the development of improved therapies, not only for kidney cancer but for many, if not all, cancer types. The oncogenic PI3K/Akt, NF-kB and MAPK pathways are critical for tumorigenesis. The sonic hedgehog (SHH) signaling pathway is crucial to normal development.

Results: By quantitative RT-PCR and immunoblot, we report that the SHH signaling pathway is constitutively reactivated in tumors independently of the von Hippel-Lindau (VHL) tumor suppressor gene expression which is inactivated in the majority of CRCC. The inhibition of the SHH signaling pathway by the specific inhibitor cyclopamine abolished CRCC cell growth as assessed by cell counting, BrdU incorporation studies, fluorescence-activated cell sorting and beta-galactosidase staining. Importantly, inhibition of the SHH pathway induced tumor regression in nude mice through inhibition of cell proliferation and neo-vascularization, and induction of apoptosis but not senescence assessed by in vivo studies, immunoblot and immunohistochemistry. Gli1, cyclin D1, Pax2, Lim1, VEGF, and TGF-beta were exclusively expressed in tumors and were shown to be regulated by SHH, as evidenced by immunoblot after SHH inhibition. Using specific inhibitors and immunoblot, the activation of the oncogenic PI3K/Akt, NF-kB and MAPK pathways was decreased by SHH inhibition.

Conclusions: These findings support targeting SHH for the treatment of CRCC and pave the way for innovative and additional investigations in a broad range of cancers.

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Related in: MedlinePlus

All the SHH signaling pathway components are expressed in human CRCC tumors. (A) Western blot analysis of the SHH ligand in 9 human tumors (T1 ...) and normal corresponding tissues (N1 ...) lysates incubated with antibodies against human SHH ligand and corresponding β-actin. The gels shown are representative for at least 3 independent experiments. (B) Quantitative gene expression of Ptch1 and Smo receptors, and of the Gli1 transcription factor in the same normal/tumoral tissue pairs shown in (A). Results are representative of 4 independent experiments.
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Figure 2: All the SHH signaling pathway components are expressed in human CRCC tumors. (A) Western blot analysis of the SHH ligand in 9 human tumors (T1 ...) and normal corresponding tissues (N1 ...) lysates incubated with antibodies against human SHH ligand and corresponding β-actin. The gels shown are representative for at least 3 independent experiments. (B) Quantitative gene expression of Ptch1 and Smo receptors, and of the Gli1 transcription factor in the same normal/tumoral tissue pairs shown in (A). Results are representative of 4 independent experiments.

Mentions: The SHH ligand was detected in all tumor samples as well as in normal corresponding tissues for all stages except for patient 8 (T8) where SHH was undetectable in normal tissue (N8) (Figure 2A).


The sonic hedgehog signaling pathway is reactivated in human renal cell carcinoma and plays orchestral role in tumor growth.

Dormoy V, Danilin S, Lindner V, Thomas L, Rothhut S, Coquard C, Helwig JJ, Jacqmin D, Lang H, Massfelder T - Mol. Cancer (2009)

All the SHH signaling pathway components are expressed in human CRCC tumors. (A) Western blot analysis of the SHH ligand in 9 human tumors (T1 ...) and normal corresponding tissues (N1 ...) lysates incubated with antibodies against human SHH ligand and corresponding β-actin. The gels shown are representative for at least 3 independent experiments. (B) Quantitative gene expression of Ptch1 and Smo receptors, and of the Gli1 transcription factor in the same normal/tumoral tissue pairs shown in (A). Results are representative of 4 independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2803450&req=5

Figure 2: All the SHH signaling pathway components are expressed in human CRCC tumors. (A) Western blot analysis of the SHH ligand in 9 human tumors (T1 ...) and normal corresponding tissues (N1 ...) lysates incubated with antibodies against human SHH ligand and corresponding β-actin. The gels shown are representative for at least 3 independent experiments. (B) Quantitative gene expression of Ptch1 and Smo receptors, and of the Gli1 transcription factor in the same normal/tumoral tissue pairs shown in (A). Results are representative of 4 independent experiments.
Mentions: The SHH ligand was detected in all tumor samples as well as in normal corresponding tissues for all stages except for patient 8 (T8) where SHH was undetectable in normal tissue (N8) (Figure 2A).

Bottom Line: The sonic hedgehog (SHH) signaling pathway is crucial to normal development.Gli1, cyclin D1, Pax2, Lim1, VEGF, and TGF-beta were exclusively expressed in tumors and were shown to be regulated by SHH, as evidenced by immunoblot after SHH inhibition.Using specific inhibitors and immunoblot, the activation of the oncogenic PI3K/Akt, NF-kB and MAPK pathways was decreased by SHH inhibition.

View Article: PubMed Central - HTML - PubMed

Affiliation: INSERM U682, Section of Renal Cancer and Renal Physiopathology, University of Strasbourg, School of Medicine, Strasbourg, 67085 France. valerian.dormoy@medecine.u-strasbg.fr

ABSTRACT

Background: Human clear cell renal cell carcinoma (CRCC) remains resistant to therapies. Recent advances in Hypoxia Inducible Factors (HIF) molecular network led to targeted therapies, but unfortunately with only limited clinical significance. Elucidating the molecular processes involved in kidney tumorigenesis and resistance is central to the development of improved therapies, not only for kidney cancer but for many, if not all, cancer types. The oncogenic PI3K/Akt, NF-kB and MAPK pathways are critical for tumorigenesis. The sonic hedgehog (SHH) signaling pathway is crucial to normal development.

Results: By quantitative RT-PCR and immunoblot, we report that the SHH signaling pathway is constitutively reactivated in tumors independently of the von Hippel-Lindau (VHL) tumor suppressor gene expression which is inactivated in the majority of CRCC. The inhibition of the SHH signaling pathway by the specific inhibitor cyclopamine abolished CRCC cell growth as assessed by cell counting, BrdU incorporation studies, fluorescence-activated cell sorting and beta-galactosidase staining. Importantly, inhibition of the SHH pathway induced tumor regression in nude mice through inhibition of cell proliferation and neo-vascularization, and induction of apoptosis but not senescence assessed by in vivo studies, immunoblot and immunohistochemistry. Gli1, cyclin D1, Pax2, Lim1, VEGF, and TGF-beta were exclusively expressed in tumors and were shown to be regulated by SHH, as evidenced by immunoblot after SHH inhibition. Using specific inhibitors and immunoblot, the activation of the oncogenic PI3K/Akt, NF-kB and MAPK pathways was decreased by SHH inhibition.

Conclusions: These findings support targeting SHH for the treatment of CRCC and pave the way for innovative and additional investigations in a broad range of cancers.

Show MeSH
Related in: MedlinePlus