TY - JOUR
T1 - RPL24
T2 - A potential therapeutic target whose depletion or acetylation inhibits polysome assembly and cancer cell growth
AU - Wilson-Edell, Kathleen A.
AU - Kehasse, Amanuel
AU - Scott, Gary K.
AU - Yau, Christina
AU - Rothschild, Daniel E.
AU - Schilling, Birgit
AU - Gabriel, Bianca S.
AU - Yevtushenko, Mariya A.
AU - Hanson, Ingrid M.
AU - Held, Jason M.
AU - Gibson, Bradford W.
AU - Benz, Christopher C.
PY - 2014
Y1 - 2014
N2 - Partial loss of large ribosomal subunit protein 24 (RPL24) function is known to protect mice against Akt or Myc-driven cancers, in part via translational inhibition of a subset of cap(eIF4E)-dependently translated mRNAs. The role of RPL24 in human malignancies is unknown. By analyzing a public dataset of matched human breast cancers and normal mammary tissue, we found that breast cancers express significantly more RPL24 than matched normal breast samples. Depletion of RPL24 in breast cancer cells by >70% reduced cell viability by 80% and decreased protein expression of the eIF4E-dependently translated proteins cyclin D1 (75%), survivin (46%) and NBS1 (30%) without altering GAPDH or beta-tubulin levels. RPL24 knockdown also reduced 80S subunit levels relative to 40S and 60S levels. These effects on expression of eIF4E-dependent proteins and ribosome assembly were mimicked by 2-24 h treatment with the pan-HDACi, trichostatin A (TSA), which induced acetylation of 15 different polysome-associated proteins including RPL24. Furthermore, HDAC6-selective inhibition or HDAC6 knockdown induced ribosomal protein acetylation. Via mass spectrometry, we found that 60S-associated, but not, polysome-associated, RPL24 undergoes HDACi-induced acetylation on K27. Thus, RPL24 K27 acetylation may play a role in ribosome assembly. These findings point toward a novel acetylation-dependent polysome assembly mechanism regulating tumorigenesis.
AB - Partial loss of large ribosomal subunit protein 24 (RPL24) function is known to protect mice against Akt or Myc-driven cancers, in part via translational inhibition of a subset of cap(eIF4E)-dependently translated mRNAs. The role of RPL24 in human malignancies is unknown. By analyzing a public dataset of matched human breast cancers and normal mammary tissue, we found that breast cancers express significantly more RPL24 than matched normal breast samples. Depletion of RPL24 in breast cancer cells by >70% reduced cell viability by 80% and decreased protein expression of the eIF4E-dependently translated proteins cyclin D1 (75%), survivin (46%) and NBS1 (30%) without altering GAPDH or beta-tubulin levels. RPL24 knockdown also reduced 80S subunit levels relative to 40S and 60S levels. These effects on expression of eIF4E-dependent proteins and ribosome assembly were mimicked by 2-24 h treatment with the pan-HDACi, trichostatin A (TSA), which induced acetylation of 15 different polysome-associated proteins including RPL24. Furthermore, HDAC6-selective inhibition or HDAC6 knockdown induced ribosomal protein acetylation. Via mass spectrometry, we found that 60S-associated, but not, polysome-associated, RPL24 undergoes HDACi-induced acetylation on K27. Thus, RPL24 K27 acetylation may play a role in ribosome assembly. These findings point toward a novel acetylation-dependent polysome assembly mechanism regulating tumorigenesis.
KW - Breast cancer
KW - EIF6
KW - HDACs
KW - RPL24
KW - Ribosome assembly
KW - Translation
UR - http://www.scopus.com/inward/record.url?scp=84905011882&partnerID=8YFLogxK
U2 - 10.18632/oncotarget.2099
DO - 10.18632/oncotarget.2099
M3 - Article
C2 - 24970821
AN - SCOPUS:84905011882
SN - 1949-2553
VL - 5
SP - 5165
EP - 5176
JO - Oncotarget
JF - Oncotarget
IS - 13
ER -