1: Cancer Genet Cytogenet. 2003 Jul 15;144(2):125-33. 

Cytogenetic and molecular findings related to rhabdomyosarcoma. An analysis of
seven cases.

Gil-Benso R, Lopez-Gines C, Carda C, Lopez-Guerrero JA, Ferrer J, Pellin-Perez
A, Llombart-Bosch A.

Department of Pathology, Medical School, University of Valencia, Avda. Blasco
Ibanez 17, Valencia 46010, Spain.

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in childhood.
Histologically, it is subdivided histologically into two main subtypes: alveolar
(ARMS) and embryonal (ERMS). ARMS is characterized by t(2;13)(q35;q14) or its
variant t(1;13)(p36;q14), which fuse PAX3 and PAX7, respectively, with FKHR to
produce chimeric genes. ERMS is frequently associated with loss of
heterozygosity of 11p15.5. We investigated seven RMS (three ARMS and four ERMS)
by means of cytogenetic, fluorescence in situ hybridization, and molecular
analyses, including the study of the main genes implicated in the G1- to S-phase
cell cycle transition, and correlated these studies with pathologic findings and
clinical outcome. All tumors showed clonal, numerical, and structural
chromosomal abnormalities. Two ARMS had the t(2;13)(q35;q14) and the third a
PAX7/FKHR fusion, a cryptic t(1;13)(p36;q14), undetected by cytogenetic
techniques, but revealed by reverse transcriptase polymerase chain reaction. One
ERMS showed a der(11)t(3;11)(p21;p15) as a sole structural anomaly. Gene
amplification was seen in four tumors, as double minutes or in the form of
homogeneously staining regions. Overexpression of MYCN oncogene was found in two
ARMS; N-myc DNA probe detected oncogene amplification located on the double
minutes of these cases. Analysis of the regulatory genes responsible for G1- to
S-phase transition showed a homozygous deletion of the 9p21 locus genes in a
spindle-cell ERMS.

PMID: 12850375 [PubMed - indexed for MEDLINE]


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2: J Biol Chem. 2002 Sep 20;277(38):34815-25. Epub 2002 Jul 2. 

The expression of the developmentally regulated proto-oncogene Pax-3 is
modulated by N-Myc.

Harris RG, White E, Phillips ES, Lillycrop KA.

Department of Biochemistry and Molecular Biology, School of Biological Sciences,
University of Southampton, Bassett Crescent East, Southampton SO16 7PX, United
Kingdom.

N-Myc is a member of the Myc family of transcription factors that have been
shown to play a pivotal role in cell proliferation and differentiation. In this
report, we have investigated the relationship between N-Myc and the
developmental control gene Pax-3. Using transient transfection assays, we show
that the Pax-3 promoter is activated by both N-Myc-Max and c-Myc-Max. Moreover,
we show that Myc regulation of Pax-3 promoter activity is dependent upon a
noncanonical E box site in the 5' promoter region of Pax-3. In addition, we show
that ectopic expression of both N-Myc and c-Myc leads to increased expression of
Pax-3 mRNA. Furthermore, we show that Pax-3 mRNA expression is cell
cycle-regulated and that the 5' promoter region of Pax-3 (bp -1578 to +56) can
direct cell cycle-dependent gene expression with kinetics similar to that of the
endogenous transcript. Site-directed mutagenesis of the E box site within the
Pax-3 promoter significantly altered the pattern of expression through the cell
cycle. These results suggest that the Myc family of transcription factors may
modulate Pax-3 expression in vivo.

PMID: 12095979 [PubMed - indexed for MEDLINE]


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