Sonic Hedgehog pathway

Sonic Hedgehog pathway

Sonic Hedgehog pathway is one of the complex signal transduction mechanism that controls or governs the process of cellular development.

The Hedgehog signaling pathway plays a critical role in the morphogenesis during embryogenesis.

PTCH(patched) gene is a tumour suppressor gene

In “off” state the PTCH exists in complex with another transmembrane protein called SMO(smoothened) which prevents SMO to activate GLI-1( Glioma associated Oncogene 1) proteins and thus cell division

Pathogenesis of several tumours involves mutations in PTCH (patched) gene, a tumour suppression gene which results in uncontrolled activation of Hedgehog pathway signaling.

Loss of PTCH function, results in constitutive activation of SMO and GLI-1 resulting in unregulated cell division and abnormal growth.

Loss-of-function mutations within this Sonic Hedgehog pathwayresults in holoprosencephaly

Tumours known to have occurred through this pathway are
a. Basal cell carcinoma,
b. medulloblastoma
c. pancreatic carcinomas

CLICK HERE    to read  Pathology of Basal cell carcinoma