The results demonstrate that tumor profiling in archival tissue samples is a useful tool for identifying diagnostic markers and potential therapeutic targets and suggests that these HRAS/ PIK3CA mutations play a critical role in the genesis of RMS.
Additional in trans DICER1 missense somatic mutations in the IIIb DICER1 domain were found both in the cystic nephroma and in the rhabdomyosarcoma, suggesting that neoplasms in this family might arise from the unusual two-hit mechanism for DICER-derived tumorigenesis in which after the presence of a truncated constitutive protein, a neomorphic DICER1 activity is somatically adquired.
Two cases of primary supratentorial intracranial rhabdomyosarcoma with DICER1 mutation which may belong to a "spindle cell sarcoma with rhabdomyosarcoma-like feature, DICER1 mutant".
These data suggest that the genetic progression in rhabdomyosarcoma from MVA and non-MVA cases may be similar, but that somatic BUB1B mutations are unlikely to be common in sporadic childhood cancers known to be associated with MVA.
We identified Bub1b as an essential element for the growth and survival of rhabdomyosarcoma (RMS) cells using a bar-coded, tetracycline-inducible short hairpin RNA (shRNA) library screen.
In family 2, immunohistochemistry analysis showed isolated loss of PMS2 expression in all tumours in the affected patients, including rhabdomyosarcoma itself and the surrounding normal tissue.
In family 2, immunohistochemistry analysis showed isolated loss of PMS2 expression in all tumours in the affected patients, including rhabdomyosarcoma itself and the surrounding normal tissue.
Since IGF-II has been indicated as an autocrine growth factor for rhabdomyosarcoma cells, these findings strongly suggest that acquisition of a double dosage of active IGF-II gene is an important step for the initiation or progression of rhabdomyosarcoma tumorigenesis.
From the investigated 17 samples, seven (41%) showed homozygous mutation of MYOD1, indicating a critical role in this rare subtype of adult spindle cell RMS, while no mutations were found in any of the other genes involved in myogenic differentiation.
We have previously reported that the number of functional IGF-2 alleles is frequently increased in rhabdomyosarcoma (RMS), as a consequence of either relaxation of imprinting (LOI) or gene duplication.
We report here that insulin-like growth factor 2-binding protein 1 (IGF2BP1), an oncofetal protein, is expressed in RMS patient-derived cell lines and in primary tumours where it drives translation of the cellular inhibitor of apoptosis 1 (cIAP1), a key regulator of the nuclear factor-κB signalling pathway and of caspase-8-mediated cell death.
We previously reported loss of imprinting (LOI) of IGF2 in rhabdomyosarcoma (RMS) where IGF2 has been shown to act as an autocrine growth factor and play an important role in pathogenesis.
We investigated 30 cases of MYOD1-mutant rhabdomyosarcoma (12 previously reported and 18 newly diagnosed) with an age range of 2-94 years, including 15 children.
We have performed the RT-PCR assay to analyze RMS for the presence of expression of MyoD1 gene and for the presence of chimeric transcripts PAX3/FKHR or PAX7/FKHR.
Furthermore, the regulatory-gene analyses indicated that these 2 sublines represented 2 distinct differentiation stages of myoblasts, and that MyoD1 and myogenin could serve as the lineage marker and the differentiation marker, respectively, of human rhabdomyosarcoma.