Estrogen receptor beta (ERβ) produces autophagy and necroptosis in human seminoma cell line through the binding of the Sp1 on the phosphatase and tensin homolog deleted from chromosome 10 (PTEN) promoter gene.
Testicular germ cell tumors are the most common tumor in male and the least studied. We focused on human seminoma using the TCAM2 cell line. Through ERβ, 10 nM estradiol (E2) was able to induce PTEN gene expression and promoter transactivation. Transient transfections, ChIP and EMSA assays evidenced the 5'-flanking region of PTEN gene promoter E2-responsive. The ERβ binding to the Sp1 on PTEN promoter decreased cell survival. The presence of ERβ or PTEN is necessary to induce the loss of cell survival upon E2, addressing their cooperation in this action. pAKT and AKT expression decreased under E2 and DPN, while known apoptotic markers appeared to be unchanged. The PI3K/AKT pathway inhibition also leads to autophagy: E2 and DPN enhanced the expression of autophagy-related markers such as PI3III, Beclin 1, AMBRA and UVRAG. MDC and TEM assays confirmed E2-induced autophagy. The absence of DNA fragmentation, caspase 9 and PARP1 cleavages suggested that necroptosis and/or parthanatos may occur. FACS analysis, LDH assay and RIP1 expression attested this hypothesis. Our study reveals a unique mechanism through which ERβ/PTEN signaling induces cell death in TCAM2 by autophagy and necroptosis. These data, supporting estrogen-dependency of human seminoma, propose ERβ ligands for therapeutic use in the treatment of this pathological condition.
Department of Pharmaco-Biology, Post-Graduate School of Clinical Pathology, University of Calabria, Rende, Italy.
Carmela
C
Guido
Salvatore
S
Panza
Marta
M
Santoro
Paola
P
Avena
Maria Luisa
ML
Panno
Ida
I
Perrotta
Francesca
F
Giordano
Ivan
I
Casaburi
Stefania
S
Catalano
Francesca
F
De Amicis
Federica
F
Sotgia
Michael P
MP
Lisanti
Sebastiano
S
Andò
Saveria
S
Aquila
D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis; D001343:Autophagy; D000071186:Beclin-1; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D004958:Estradiol; D047629:Estrogen Receptor beta / Q000378:metabolism*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis; D051059:PTEN Phosphohydrolase / Q000235:genetics / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000096:biosynthesis; D000081082:Phosphoinositide-3 Kinase Inhibitors; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics; D018239:Seminoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000235:genetics; D013736:Testicular Neoplasms / Q000235:genetics*; D014158:Transcription, Genetic; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D000071186:Beclin-1; D053453:Caspase 9; D004958:Estradiol; D047629:Estrogen Receptor beta; D008565:Membrane Proteins; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D051057:Proto-Oncogene Proteins c-akt; D025521:Tumor Suppressor Proteins; C553334:AMBRA1 protein, human; C491997:BECN1 protein, human; C408122:UVRAG protein, human; C499320:PARP1 protein, human; C494929:PTEN protein, human