Limits...
Developmental expression and differentiation-related neuron-specific splicing of metastasis suppressor 1 (Mtss1) in normal and transformed cerebellar cells.

Glassmann A, Molly S, Surchev L, Nazwar TA, Holst M, Hartmann W, Baader SL, Oberdick J, Pietsch T, Schilling K - BMC Dev. Biol. (2007)

Bottom Line: In the adult CNS, Mtss1 is found exclusively in cerebellar Purkinje cells.Both the pattern of expression and splicing of Mtss1 is developmentally regulated in the murine cerebellum.These findings are discussed with a view on the potential role of Mtss1 for cytoskeletal dynamics in developing and mature cerebellar neurons.

View Article: PubMed Central - HTML - PubMed

Affiliation: Anatomisches Institut, Anatomie & Zellbiologie, University of Bonn, Bonn, Germany. alexander.glassmann@uni-bonn.de

ABSTRACT

Background: Mtss1 encodes an actin-binding protein, dysregulated in a variety of tumors, that interacts with sonic hedgehog/Gli signaling in epidermal cells. Given the prime importance of this pathway for cerebellar development and tumorigenesis, we assessed expression of Mtss1 in the developing murine cerebellum and human medulloblastoma specimens.

Results: During development, Mtss1 is transiently expressed in granule cells, from the time point they cease to proliferate to their synaptic integration. It is also expressed by granule cell precursor-derived medulloblastomas. In the adult CNS, Mtss1 is found exclusively in cerebellar Purkinje cells. Neuronal differentiation is accompanied by a switch in Mtss1 splicing. Whereas immature granule cells express a Mtss1 variant observed also in peripheral tissues and comprising exon 12, this exon is replaced by a CNS-specific exon, 12a, in more mature granule cells and in adult Purkinje cells. Bioinformatic analysis of Mtss1 suggests that differential exon usage may affect interaction with Fyn and Src, two tyrosine kinases previously recognized as critical for cerebellar cell migration and histogenesis. Further, this approach led to the identification of two evolutionary conserved nuclear localization sequences. These overlap with the actin filament binding site of Mtss1, and one also harbors a potential PKA and PKC phosphorylation site.

Conclusion: Both the pattern of expression and splicing of Mtss1 is developmentally regulated in the murine cerebellum. These findings are discussed with a view on the potential role of Mtss1 for cytoskeletal dynamics in developing and mature cerebellar neurons.

Show MeSH

Related in: MedlinePlus

Expression of Mtss1 exons 11–13 in human medulloblastomas and medulloblastoma derived cell lines. A: Lanes 1–5: classical medulloblatoma samples D1198, D1127, D1049, D1185 and D963, respectively; lanes 6–10: desmoplastic medulloblastoma samples D86, D978, D82, D1401, and D1062; lanes H1, H2: fetal human cerebellar samples R1626 and R1628. Lane C is a negative control. The band indicative of the splice variant containing exons 11/12a/12/13 is hardly visible in this reproduction. B: In DAOY (D) and D-283Med medulloblastoma cell lines, bands representing the splice variants 11/12/13 and 11/13 predominate. Note absence of the band indicative of the splice variant 11/12a/13, which should comigrate with the prominent band of sample 10 shown for comparison. Lane C is a negative control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2194783&req=5

Figure 4: Expression of Mtss1 exons 11–13 in human medulloblastomas and medulloblastoma derived cell lines. A: Lanes 1–5: classical medulloblatoma samples D1198, D1127, D1049, D1185 and D963, respectively; lanes 6–10: desmoplastic medulloblastoma samples D86, D978, D82, D1401, and D1062; lanes H1, H2: fetal human cerebellar samples R1626 and R1628. Lane C is a negative control. The band indicative of the splice variant containing exons 11/12a/12/13 is hardly visible in this reproduction. B: In DAOY (D) and D-283Med medulloblastoma cell lines, bands representing the splice variants 11/12/13 and 11/13 predominate. Note absence of the band indicative of the splice variant 11/12a/13, which should comigrate with the prominent band of sample 10 shown for comparison. Lane C is a negative control.

Mentions: Cerebellar granule cells, or their precursors, have been identified as a cellular origin of medulloblastomas. Based on their morphology, pattern of gene expression and biology, two major subsets of medulloblastomas have been defined, referred to as classical and desmoplastic types, respectively [32-34]. Analysis of mRNAs obtained from 5 classic and 5 desmoplastic tumor specimens [35] revealed that all of them expressed Mtss1, and specifically the same basic splice variants within the region of exons 11–13 as described above (Fig 4A). Among individual tumor samples, the relative intensities of these bands varied, and again as described for the developing cerebellum, the most conspicuous differences were observed for the bands representing exon combinations 11/12/13 and 11/12a/13. In two cell lines derived from human medulloblastomas (DAOY and D-283Med), exon combinations 11/13 and 11/12/13 were prominent, whereas the combinations 11/12/12a/13 and 11/12a/13 could not be observed (Fig 4B). As expected from the murine data, the most prominent band in mRNA obtained from normal, immature human cerebellar tissue was the one indicative of the exon combination 11/12a/13. The band representing the exon combination 11/12/12a/13 of Mtss1 appeared very weak in all human specimens analyzed.


Developmental expression and differentiation-related neuron-specific splicing of metastasis suppressor 1 (Mtss1) in normal and transformed cerebellar cells.

Glassmann A, Molly S, Surchev L, Nazwar TA, Holst M, Hartmann W, Baader SL, Oberdick J, Pietsch T, Schilling K - BMC Dev. Biol. (2007)

Expression of Mtss1 exons 11–13 in human medulloblastomas and medulloblastoma derived cell lines. A: Lanes 1–5: classical medulloblatoma samples D1198, D1127, D1049, D1185 and D963, respectively; lanes 6–10: desmoplastic medulloblastoma samples D86, D978, D82, D1401, and D1062; lanes H1, H2: fetal human cerebellar samples R1626 and R1628. Lane C is a negative control. The band indicative of the splice variant containing exons 11/12a/12/13 is hardly visible in this reproduction. B: In DAOY (D) and D-283Med medulloblastoma cell lines, bands representing the splice variants 11/12/13 and 11/13 predominate. Note absence of the band indicative of the splice variant 11/12a/13, which should comigrate with the prominent band of sample 10 shown for comparison. Lane C is a negative control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2194783&req=5

Figure 4: Expression of Mtss1 exons 11–13 in human medulloblastomas and medulloblastoma derived cell lines. A: Lanes 1–5: classical medulloblatoma samples D1198, D1127, D1049, D1185 and D963, respectively; lanes 6–10: desmoplastic medulloblastoma samples D86, D978, D82, D1401, and D1062; lanes H1, H2: fetal human cerebellar samples R1626 and R1628. Lane C is a negative control. The band indicative of the splice variant containing exons 11/12a/12/13 is hardly visible in this reproduction. B: In DAOY (D) and D-283Med medulloblastoma cell lines, bands representing the splice variants 11/12/13 and 11/13 predominate. Note absence of the band indicative of the splice variant 11/12a/13, which should comigrate with the prominent band of sample 10 shown for comparison. Lane C is a negative control.
Mentions: Cerebellar granule cells, or their precursors, have been identified as a cellular origin of medulloblastomas. Based on their morphology, pattern of gene expression and biology, two major subsets of medulloblastomas have been defined, referred to as classical and desmoplastic types, respectively [32-34]. Analysis of mRNAs obtained from 5 classic and 5 desmoplastic tumor specimens [35] revealed that all of them expressed Mtss1, and specifically the same basic splice variants within the region of exons 11–13 as described above (Fig 4A). Among individual tumor samples, the relative intensities of these bands varied, and again as described for the developing cerebellum, the most conspicuous differences were observed for the bands representing exon combinations 11/12/13 and 11/12a/13. In two cell lines derived from human medulloblastomas (DAOY and D-283Med), exon combinations 11/13 and 11/12/13 were prominent, whereas the combinations 11/12/12a/13 and 11/12a/13 could not be observed (Fig 4B). As expected from the murine data, the most prominent band in mRNA obtained from normal, immature human cerebellar tissue was the one indicative of the exon combination 11/12a/13. The band representing the exon combination 11/12/12a/13 of Mtss1 appeared very weak in all human specimens analyzed.

Bottom Line: In the adult CNS, Mtss1 is found exclusively in cerebellar Purkinje cells.Both the pattern of expression and splicing of Mtss1 is developmentally regulated in the murine cerebellum.These findings are discussed with a view on the potential role of Mtss1 for cytoskeletal dynamics in developing and mature cerebellar neurons.

View Article: PubMed Central - HTML - PubMed

Affiliation: Anatomisches Institut, Anatomie & Zellbiologie, University of Bonn, Bonn, Germany. alexander.glassmann@uni-bonn.de

ABSTRACT

Background: Mtss1 encodes an actin-binding protein, dysregulated in a variety of tumors, that interacts with sonic hedgehog/Gli signaling in epidermal cells. Given the prime importance of this pathway for cerebellar development and tumorigenesis, we assessed expression of Mtss1 in the developing murine cerebellum and human medulloblastoma specimens.

Results: During development, Mtss1 is transiently expressed in granule cells, from the time point they cease to proliferate to their synaptic integration. It is also expressed by granule cell precursor-derived medulloblastomas. In the adult CNS, Mtss1 is found exclusively in cerebellar Purkinje cells. Neuronal differentiation is accompanied by a switch in Mtss1 splicing. Whereas immature granule cells express a Mtss1 variant observed also in peripheral tissues and comprising exon 12, this exon is replaced by a CNS-specific exon, 12a, in more mature granule cells and in adult Purkinje cells. Bioinformatic analysis of Mtss1 suggests that differential exon usage may affect interaction with Fyn and Src, two tyrosine kinases previously recognized as critical for cerebellar cell migration and histogenesis. Further, this approach led to the identification of two evolutionary conserved nuclear localization sequences. These overlap with the actin filament binding site of Mtss1, and one also harbors a potential PKA and PKC phosphorylation site.

Conclusion: Both the pattern of expression and splicing of Mtss1 is developmentally regulated in the murine cerebellum. These findings are discussed with a view on the potential role of Mtss1 for cytoskeletal dynamics in developing and mature cerebellar neurons.

Show MeSH
Related in: MedlinePlus