High phospho-Stathmin(Serine38) expression identifies aggressive endometrial cancer and suggests an association with PI3K inhibition.

Abstract

PURPOSE:

High Stathmin expression has recently been associated with clinical progress in endometrial cancers. Stathmin protein activity is modulated by phosphorylation, and the Serine38 site is one of four Stathmin phospho-sites. The presence and significance of pStathmin(S38) is largely unknown in human cancers, and we here examined the associations between this marker and tumor cell proliferation, clinicopathologic phenotype, and survival impact in endometrial cancer. A relationship with possible treatment targets was explored by integrated analysis of transcriptional alterations.

EXPERIMENTAL DESIGN:

Primary endometrial cancers from two independent patient series (n = 518/n = 286) were analyzed. Biomarkers were assessed by immunohistochemistry, FISH, flow cytometry, DNA oligonucleotide microarray, single-nucleotide polymorphism array, and Sanger sequencing, and related to clinicopathologic annotations and follow-up information.

RESULTS:

High pStathmin(S38) level was associated with poor prognosis, independent of other features, and correlated to increased tumor cell proliferation as well as high Stathmin levels. On the basis of transcriptional differences between high/low pStathmin(S38) tumors, phosphoinositide 3-kinase (PI3K)/mTOR/HSP90 were suggested as possible targets in pStathmin(S38)-high cases. High pStathmin(S38) was associated with several PI3K pathway alterations: amplification of the 3q26 region, increased PIK3CA copy number (FISH) and a PI3K activation score (all P < 0.05).

CONCLUSIONS:

High pStathmin(S38) is a novel biomarker of increased tumor cell proliferation and impaired prognosis as reported here for independent cohorts of endometrial cancer and not previously shown in human cancer. Our data support a rationale for further studies exploring effects of drugs inhibiting the PI3K signaling pathway in pStathmin(S38)-high endometrial cancer, including a potential value of pStathmin(S38) in predicting response to PI3K/mTOR/HSP90 inhibitors.

• Authors: Elisabeth Wik, Even Birkeland, Jone Trovik, Henrica M J Werner, Erling A Hoivik, Siv Mjos, Camilla Krakstad, Kanthida Kusonmano, Karen Mauland, Ingunn M Stefansson, Frederik Holst, Kjell Petersen, Anne M Oyan, Ronald Simon, Karl H Kalland, William Ricketts, Lars A Akslen, Helga B Salvesen
• Journal: Clinical cancer research : an official journal of the American Association for Cancer Research (Clin Cancer Res) Vol. 19 Issue 9 Pg. 2331-41 (May 01 2013) ISSN: 1557-3265 [Electronic] United States
• PMID: 23538402 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: ©2013 AACR.

Chemical References

• Antineoplastic Agents
• Biomarkers, Tumor
• Phosphoinositide-3 Kinase Inhibitors
• Phosphoproteins
• STMN1 protein, human
• Stathmin
• MTOR protein, human
• Class I Phosphatidylinositol 3-Kinases
• PIK3CA protein, human
• TOR Serine-Threonine Kinases

Topics

• Antineoplastic Agents (pharmacology)
• Biomarkers, Tumor (genetics, metabolism)
• Carcinoma (metabolism, mortality, pathology)
• Cell Proliferation
• Chromosomes, Human, Pair 3
• Class I Phosphatidylinositol 3-Kinases
• Endometrial Neoplasms (metabolism, mortality, pathology)
• Female
• Gene Amplification
• Humans
• Kaplan-Meier Estimate
• Oligonucleotide Array Sequence Analysis
• Phenotype
• Phosphatidylinositol 3-Kinases (genetics, metabolism)
• Phosphoinositide-3 Kinase Inhibitors
• Phosphoproteins (genetics, metabolism)
• Phosphorylation
• Prognosis
• Proportional Hazards Models
• Protein Processing, Post-Translational
• Stathmin (genetics, metabolism)
• TOR Serine-Threonine Kinases (metabolism)
• Transcriptome