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GSE38519
Homo sapiens
4 Downloadable Samples
Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Bortezomib (Velcade) is widely used for the treatment of various human cancers, however, its mechanisms of action are not fully understood, particularly in myeloid malignancies. Bortezomib is a selective and reversible inhibitor of the proteasome. Paradoxically, we find that Bortezomib induces proteasome-independent degradation of TRAF6 protein, but not mRNA, in Myelodysplastic syndrome (MDS) and Acute Myeloid Leukemia (AML) cell lines and primary cells. The reduction in TRAF6 protein coincides with Bortezomib-induced autophagy, and subsequently with apoptosis in MDS/AML cells. RNAi-mediated knockdown of TRAF6 sensitized Bortezomib-sensitive and -resistant cell lines, underscoring the importance of TRAF6 in Bortezomib-induced cytotoxicity. Bortezomib-resistant cells expressing an shRNA targeting TRAF6 were resensitized to the cytotoxic effects of Bortezomib due to down-regulation of the proteasomal subunit alpha-1 (PSMA1). To uncover the molecular consequences following loss of TRAF6 in MDS/AML cells, we applied gene expression profiling and identified an apoptosis gene signature. Knockdown of TRAF6 in MDS/AML cell lines or patient samples resulted in rapid apoptosis and impaired malignant hematopoietic stem/progenitor function. In summary, we describe novel mechanisms by which TRAF6 is regulated through Bortezomib/autophagy-mediated degradation and by which it alters MDS/AML sensitivity to Bortezomib by controlling PSMA1 expression.
Publication Title
Cytotoxic effects of bortezomib in myelodysplastic syndrome/acute myeloid leukemia depend on autophagy-mediated lysosomal degradation of TRAF6 and repression of PSMA1.
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Treatment
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Genome 430A 2.0 Array (mouse430a2)
Description
In the adult mammalian testis, spermatogenic differentiation starts from a minute population of spermatogonial stem cells (SSCs). SSCs are generated after birth from the fetal gonocytes, themselves derived from the primordial germ cells (PGCs), which are specified during the first days after implantation. Transcriptome profiling of purified preparations evidenced the preferential accumulation in SSCs of transcripts of PU.1 (Sfpi1), a regulatory gene previously identified in hematopoietic progenitors. In situ immunolabeling and RNA determination showed a complex pattern of expression in the adult testis, first in SSCs and early spermatogonia followed by de novo expression in pachytene spermatocytes.
Publication Title
PU.1 (Sfpi1), a pleiotropic regulator expressed from the first embryonic stages with a crucial function in germinal progenitors.
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