Rho-associated kinase is a therapeutic target in neuroblastoma

Abstract

Neuroblastoma is a peripheral neural system tumor that originates from the neural crest and is the most common and deadly tumor of infancy. Here we show that neuroblastoma harbors frequent mutations of genes controlling the Rac/Rho signaling cascade important for proper migration and differentiation of neural crest cells during neuritogenesis. RhoA is activated in tumors from neuroblastoma patients, and elevated expression of Rho-associated kinase (ROCK)2 is associated with poor patient survival. Pharmacological or genetic inhibition of ROCK1 and 2, key molecules in Rho signaling, resulted in neuroblastoma cell differentiation and inhibition of neuroblastoma cell growth, migration, and invasion. Molecularly, ROCK inhibition induced glycogen synthase kinase 3β-dependent phosphorylation and degradation of MYCN protein. Small-molecule inhibition of ROCK suppressed MYCN-driven neuroblastoma growth in TH-MYCN homozygous transgenic mice and MYCN gene-amplified neuroblastoma xenograft growth in nude mice. Interference with Rho/Rac signaling might offer therapeutic perspectives for high-risk neuroblastoma.N euroblastoma is a childhood tumor of the peripheral sympathetic nervous system, causing 6% of all childhood cancers but 9% of deaths from malignant tumors in children (1, 2). Approximately half of patients present with high-risk disease characterized by unresectable primary lesions and multiple metastases (2, 3). Although survival in this group has improved, the majority of the tumors show resistance to therapy with poor patient survival despite intensive multimodal therapy, necessitating the search for new therapeutic options (2).Compared with adult tumors, pediatric cancers exhibit significantly fewer genomic aberrations and mutations. In neuroblastoma, somatically acquired amplification of MYCN, hemizygous deletions of 1p and 11q, and gain of 17q are the most common chromosomal aberrations associated with a poor prognosis (3). Exome-and whole-genome sequencing analysis of neuroblastoma has reported an overall low somatic mutation count (12 to 18, median 15), with ALK being the most frequently mutated gene (7 to 10%) (4-6). In addition, chromothripsis, PHOX2B, and ATRX mutations have also been detected in a subset of highrisk tumors (4,5).Neuritogenesis is initiated during embryogenesis by a transient population of cells called the neural crest. During embryonic development, neural crest cells migrate throughout the embryo and eventually differentiate into multiple cell types, such as neurons and glial cells of the peripheral nervous system, pigment cells, fibroblasts, smooth muscle cells, and odontoblasts. The failure of neural crest cells to differentiate can result in development of cancers such as neuroblastoma and melanoma (7). A combination of Wingless (Wnt), bone morphogenetic protein, and fibroblast growth factor (FGF) signals is required to induce the formation of the neural crest and to initiate migration of neural crest cells by acquiring cell motility through epithelialmesenchymal transition (8). The no...

Integrated proximal proteomics reveals IRS2 as a determinant of cell survival in ALK-driven neuroblastoma

“…3B), we used dasatinib to target Src and the inhibitor KD025 to target Rho-associated kinase 2 (Rock2). The latter was targeted because of the identification of regulation of a proline-directed site (data file S3) and because Rock is a therapeutic target in NB (46). Dose-response cell viability assays in NB1, SH-SY5Y, CLBGA, NBL-S, and H3122 revealed sensitivity to both dasatinib and KD025 with the exception of minimal effect of KD025 in H3122 cells (fig.…”

Insulin induces phosphorylation of pyruvate dehydrogenase through RhoA activation pathway in HepG2 cells

“…Indeed, GSK-3b was reported to be activated in a RhoAdependent manner by lysophosphatidic acid/Ga13 receptor, although the mechanism was not clearly defined in the study (32). Indeed, ROCK inhibition by HA1077 abolished p-Ser9 GSK-3b in neuroblastoma cells (33).…”

Impact of extracellular matrix properties on neuroblastoma genomic heterogeneity

“…RhoA protein plays an signi cant role in mechanotransduction, as it mediates focal adhesions and stress ber formation [69]. Its reduced signal (associated with 3p) has been linked to growth and metastasis in colorectal tumors [70,71]. Moreover, in these tumors RHOA downregulation is used to match the activation of Wnt signal pathway and inactivation of TGFβ.…”