RPPA-based protein profiling reveals eIF4G overexpression and 4E-BP1 serine 65 phosphorylation as molecular events that correspond with a pro-survival phenotype in chronic lymphocytic leukemia

Austin Y. Shull, Satish K. Noonepalle, Farrukh T. Awan, Jimei Liu, Lirong Pei, Roni J. Bollag, Huda Salman, Zhiyong Ding, Huidong Shi

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Chronic lymphocytic leukemia (CLL), the most common adult leukemia, remains incurable despite advancements in treatment regimens over the past decade. Several expression profile studies have been pursued to better understand CLL pathogenesis. However, these large-scale studies only provide information at the transcriptional level. To better comprehend the differential protein changes that take place in CLL, we performed a reverse-phase protein array (RPPA) analysis using 167 different antibodies on B-cell lysates from 18 CLL patients and 6 normal donors. From our analysis, we discovered an enrichment of protein alterations involved with mRNA translation, specifically upregulation of the translation initiator eIF4G and phosphorylation of the cap-dependent translation inhibitor 4E-BP1 at serine 65. Interestingly, 4E-BP1 phosphorylation occurred independently of AKT phosphorylation, suggesting a disconnect between PI3K/AKT pathway activation and 4E-BP1 phosphorylation. Based on these results, we treated primary CLL samples with NVP-BEZ235, a PI3K/mTOR dual inhibitor, and compared its apoptotic-inducing potential against the BTK inhibitor Ibrutinib and the PI3Kd inhibitor Idelalisib. We demonstrated that treatment with NVP-BEZ235 caused greater apoptosis, greater apoptotic cleavage of eIF4G, and greater dephosphorylation of 4E-BP1 in primary CLL cells. Taken together, these results highlight the potential dependence of eIF4G verexpression and 4E-BP1 phosphorylation in CLL survival.

Original languageEnglish (US)
Pages (from-to)14632-14645
Number of pages14
JournalOncotarget
Volume6
Issue number16
DOIs
StatePublished - Jan 1 2015

Fingerprint

Protein Array Analysis
B-Cell Chronic Lymphocytic Leukemia
Serine
Phosphorylation
Phenotype
Survival
Proteins
Phosphatidylinositol 3-Kinases
Protein Biosynthesis
Leukemia
B-Lymphocytes
Up-Regulation
Tissue Donors
Apoptosis
Antibodies
Therapeutics

Keywords

  • 4E-BP1
  • CLL
  • EIF4G
  • NVP-BEZ235
  • RPPA

ASJC Scopus subject areas

  • Oncology

Cite this

RPPA-based protein profiling reveals eIF4G overexpression and 4E-BP1 serine 65 phosphorylation as molecular events that correspond with a pro-survival phenotype in chronic lymphocytic leukemia. / Shull, Austin Y.; Noonepalle, Satish K.; Awan, Farrukh T.; Liu, Jimei; Pei, Lirong; Bollag, Roni J.; Salman, Huda; Ding, Zhiyong; Shi, Huidong.

In: Oncotarget, Vol. 6, No. 16, 01.01.2015, p. 14632-14645.

Research output: Contribution to journalArticle

Shull, Austin Y. ; Noonepalle, Satish K. ; Awan, Farrukh T. ; Liu, Jimei ; Pei, Lirong ; Bollag, Roni J. ; Salman, Huda ; Ding, Zhiyong ; Shi, Huidong. / RPPA-based protein profiling reveals eIF4G overexpression and 4E-BP1 serine 65 phosphorylation as molecular events that correspond with a pro-survival phenotype in chronic lymphocytic leukemia. In: Oncotarget. 2015 ; Vol. 6, No. 16. pp. 14632-14645.
@article{d2fa6068c5474b7f8c18188d2d6f023e,
title = "RPPA-based protein profiling reveals eIF4G overexpression and 4E-BP1 serine 65 phosphorylation as molecular events that correspond with a pro-survival phenotype in chronic lymphocytic leukemia",
abstract = "Chronic lymphocytic leukemia (CLL), the most common adult leukemia, remains incurable despite advancements in treatment regimens over the past decade. Several expression profile studies have been pursued to better understand CLL pathogenesis. However, these large-scale studies only provide information at the transcriptional level. To better comprehend the differential protein changes that take place in CLL, we performed a reverse-phase protein array (RPPA) analysis using 167 different antibodies on B-cell lysates from 18 CLL patients and 6 normal donors. From our analysis, we discovered an enrichment of protein alterations involved with mRNA translation, specifically upregulation of the translation initiator eIF4G and phosphorylation of the cap-dependent translation inhibitor 4E-BP1 at serine 65. Interestingly, 4E-BP1 phosphorylation occurred independently of AKT phosphorylation, suggesting a disconnect between PI3K/AKT pathway activation and 4E-BP1 phosphorylation. Based on these results, we treated primary CLL samples with NVP-BEZ235, a PI3K/mTOR dual inhibitor, and compared its apoptotic-inducing potential against the BTK inhibitor Ibrutinib and the PI3Kd inhibitor Idelalisib. We demonstrated that treatment with NVP-BEZ235 caused greater apoptosis, greater apoptotic cleavage of eIF4G, and greater dephosphorylation of 4E-BP1 in primary CLL cells. Taken together, these results highlight the potential dependence of eIF4G verexpression and 4E-BP1 phosphorylation in CLL survival.",
keywords = "4E-BP1, CLL, EIF4G, NVP-BEZ235, RPPA",
author = "Shull, {Austin Y.} and Noonepalle, {Satish K.} and Awan, {Farrukh T.} and Jimei Liu and Lirong Pei and Bollag, {Roni J.} and Huda Salman and Zhiyong Ding and Huidong Shi",
year = "2015",
month = "1",
day = "1",
doi = "10.18632/oncotarget.4104",
language = "English (US)",
volume = "6",
pages = "14632--14645",
journal = "Oncotarget",
issn = "1949-2553",
publisher = "Impact Journals",
number = "16",

}

TY - JOUR

T1 - RPPA-based protein profiling reveals eIF4G overexpression and 4E-BP1 serine 65 phosphorylation as molecular events that correspond with a pro-survival phenotype in chronic lymphocytic leukemia

AU - Shull, Austin Y.

AU - Noonepalle, Satish K.

AU - Awan, Farrukh T.

AU - Liu, Jimei

AU - Pei, Lirong

AU - Bollag, Roni J.

AU - Salman, Huda

AU - Ding, Zhiyong

AU - Shi, Huidong

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Chronic lymphocytic leukemia (CLL), the most common adult leukemia, remains incurable despite advancements in treatment regimens over the past decade. Several expression profile studies have been pursued to better understand CLL pathogenesis. However, these large-scale studies only provide information at the transcriptional level. To better comprehend the differential protein changes that take place in CLL, we performed a reverse-phase protein array (RPPA) analysis using 167 different antibodies on B-cell lysates from 18 CLL patients and 6 normal donors. From our analysis, we discovered an enrichment of protein alterations involved with mRNA translation, specifically upregulation of the translation initiator eIF4G and phosphorylation of the cap-dependent translation inhibitor 4E-BP1 at serine 65. Interestingly, 4E-BP1 phosphorylation occurred independently of AKT phosphorylation, suggesting a disconnect between PI3K/AKT pathway activation and 4E-BP1 phosphorylation. Based on these results, we treated primary CLL samples with NVP-BEZ235, a PI3K/mTOR dual inhibitor, and compared its apoptotic-inducing potential against the BTK inhibitor Ibrutinib and the PI3Kd inhibitor Idelalisib. We demonstrated that treatment with NVP-BEZ235 caused greater apoptosis, greater apoptotic cleavage of eIF4G, and greater dephosphorylation of 4E-BP1 in primary CLL cells. Taken together, these results highlight the potential dependence of eIF4G verexpression and 4E-BP1 phosphorylation in CLL survival.

AB - Chronic lymphocytic leukemia (CLL), the most common adult leukemia, remains incurable despite advancements in treatment regimens over the past decade. Several expression profile studies have been pursued to better understand CLL pathogenesis. However, these large-scale studies only provide information at the transcriptional level. To better comprehend the differential protein changes that take place in CLL, we performed a reverse-phase protein array (RPPA) analysis using 167 different antibodies on B-cell lysates from 18 CLL patients and 6 normal donors. From our analysis, we discovered an enrichment of protein alterations involved with mRNA translation, specifically upregulation of the translation initiator eIF4G and phosphorylation of the cap-dependent translation inhibitor 4E-BP1 at serine 65. Interestingly, 4E-BP1 phosphorylation occurred independently of AKT phosphorylation, suggesting a disconnect between PI3K/AKT pathway activation and 4E-BP1 phosphorylation. Based on these results, we treated primary CLL samples with NVP-BEZ235, a PI3K/mTOR dual inhibitor, and compared its apoptotic-inducing potential against the BTK inhibitor Ibrutinib and the PI3Kd inhibitor Idelalisib. We demonstrated that treatment with NVP-BEZ235 caused greater apoptosis, greater apoptotic cleavage of eIF4G, and greater dephosphorylation of 4E-BP1 in primary CLL cells. Taken together, these results highlight the potential dependence of eIF4G verexpression and 4E-BP1 phosphorylation in CLL survival.

KW - 4E-BP1

KW - CLL

KW - EIF4G

KW - NVP-BEZ235

KW - RPPA

UR - http://www.scopus.com/inward/record.url?scp=84931037273&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84931037273&partnerID=8YFLogxK

U2 - 10.18632/oncotarget.4104

DO - 10.18632/oncotarget.4104

M3 - Article

C2 - 25999352

AN - SCOPUS:84931037273

VL - 6

SP - 14632

EP - 14645

JO - Oncotarget

JF - Oncotarget

SN - 1949-2553

IS - 16

ER -