AKT induces senescence in primary esophageal epithelial cells but is permissive for differentiation as revealed in organotypic culture

Oyama, Kenji; Okawa, Takaomi; Nakagawa, Hiroshi; Takaoka, Munenori; Cd, Andl; Sh, Kim; Klein‐Szanto, Andres J.; Ja, Diehl; Herlyn, Meenhard; El‐Deiry, Wafik S.; Ak, Rustgi

doi:10.1038/sj.onc.1210025

Cited by 46 publications

(42 citation statements)

References 32 publications

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“…To mimic the tissue microenvironment, epithelial cells were overlaid on an ECM gel mixed with human fetal esophageal fibroblasts, and after 11 d, a liquid-air interface was created, thereby leading to stratification of the squamous epithelium, which resembles the human esophageal squamous epithelium Harada et al 2003;Oyama et al 2007). The EPC2-hTERT-EGFR cells ( Fig.…”

Section: Resultsmentioning

confidence: 99%

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The functional interplay between EGFR overexpression, hTERT activation, and p53 mutation in esophageal epithelial cells with activation of stromal fibroblasts induces tumor development, invasion, and differentiation

Okawa¹,

Michaylira²,

Kalabis³

et al. 2007

Genes Dev.

160

161

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Esophageal cancer is a prototypic squamous cell cancer that carries a poor prognosis, primarily due to presentation at advanced stages. We used human esophageal epithelial cells as a platform to recapitulate esophageal squamous cell cancer, thereby providing insights into the molecular pathogenesis of squamous cell cancers in general. This was achieved through the retroviral-mediated transduction into normal, primary human esophageal epithelial cells of epidermal growth factor receptor (EGFR), the catalytic subunit of human telomerase (hTERT), and p53 R175H, genes that are frequently altered in human esophageal squamous cell cancer. These cells demonstrated increased migration and invasion when compared with control cells. When these genetically altered cells were placed within the in vivo-like context of an organotypic three-dimensional (3D) culture system, the cells formed a high-grade dysplastic epithelium with malignant cells invading into the stromal extracellular matrix (ECM). The invasive phenotype was in part modulated by the activation of matrix metalloproteinase-9 (MMP-9). Using pharmacological and genetic approaches to decrease MMP-9, invasion into the underlying ECM could be suppressed partially. In addition, tumor differentiation was influenced by the type of fibroblasts within the stromal ECM. To that end, fetal esophageal fibroblasts fostered a microenvironment conducive to poorly differentiated invading tumor cells, whereas fetal skin fibroblasts supported a well-differentiated tumor as illustrated by keratin "pearl" formation, a hallmark feature of well-differentiated squamous cell cancers. When inducible AKT was introduced into fetal skin esophageal fibroblasts, a more invasive, less-differentiated esophageal cancer phenotype was achieved. Invasion into the stromal ECM was attenuated by genetic knockdown of AKT1 as well as AKT2. Taken together, alterations in key oncogenes and tumor suppressor genes in esophageal epithelial cells, the composition and activation of fibroblasts, and the components of the ECM conspire to regulate the physical and biological properties of the stroma.[Keywords: Cell migration and invasion; tumor microenvironment; EGFR; p53; MMP-9; AKT] Supplemental material is available at http://www.genesdev.org. Received February 22, 2007; revised version accepted September 5, 2007. 8 These authors contributed equally to this work. 9Corresponding author. E-MAIL anil2@mail.med.upenn.edu; FAX (215) 573-5412. Article is online at http://www.genesdev.org/cgi

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Section: Resultsmentioning

confidence: 99%

“…Therefore, conditioned media were harvested at days 11, 13, and 15 and analyzed by gelatin zymography. It should be emphasized that stratification of the squamous epithelium only occurs after day 10 (Oyama et al 2007). On day 11, there is faint expression of pro-MMP-9.…”

Section: Mmp-9 Is Activated In Invading Triple Mutant Epc2-htert-egfrmentioning

confidence: 99%

The functional interplay between EGFR overexpression, hTERT activation, and p53 mutation in esophageal epithelial cells with activation of stromal fibroblasts induces tumor development, invasion, and differentiation

Okawa¹,

Michaylira²,

Kalabis³

et al. 2007

Genes Dev.

160

161

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“…In an experimental study using primary esophageal epithelial cells, inducible activation of AKT results in growth arrest and a senescent phenotype in normal epithelial cells (43). That AKT activation induces growth arrest is reminiscent of the effects of oncogenic Ras in primary human cells.…”

Section: Discussionmentioning

confidence: 99%

PIK3CA Mutation Is Associated with a Favorable Prognosis among Patients with Curatively Resected Esophageal Squamous Cell Carcinoma

Shigaki

Baba

Watanabe

et al. 2013

Clinical Cancer Research

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Purpose: PIK3CA encodes the catalytic subunit of PI3K, p110a. Mutant PIK3CA stimulates the AKT pathway and promotes cancer cell proliferation. PIK3CA mutations have been associated with poor prognosis in patients with colorectal or lung cancer. In contrast, the relationship between PIK3CA mutations and favorable prognoses has been shown in breast cancer. However, the influence of PIK3CA mutations on the prognosis of patients with esophageal squamous cell carcinoma (ESCC) remains unclear.Experimental Design: Using a nonbiased database of 219 curatively resected ESCCs and eight esophageal cancer cell lines, we evaluated PIK3CA mutational status by pyrosequencing. The expression of p53 and phosphorylated AKT (i.e., AKT activation) was evaluated by immunohistochemistry.Results: PIK3CA mutations in exon 9 and/or 20 were detected in 46 cases (21%). No ESCC cell line harbored PIK3CA mutations. PIK3CA mutations were significantly associated with phosphorylated AKT expression, but not with p53 expression, sex, age at surgery, tobacco use, alcohol use, or histologic grade. Compared with wild-type PIK3CA cases, patients with PIK3CA mutations in exons 9 and/or 20 experienced significantly better disease-free survival [log-rank P ¼ 0.0089; univariate HR: 0.37, 95% confidence interval (CI): 0.15-0.75, P ¼ 0.0042; multivariate HR: 0.34, 95% CI: 0.10-0.86, P ¼ 0.021] and overall survival (log-rank P ¼ 0.012; univariate HR: 0.38, 95% CI: 0.16-0.78, P ¼ 0.0060; multivariate HR: 0.35, 95% CI: 0.10-0.90, P ¼ 0.028).Conclusion: PIK3CA mutations in ESCC are associated with longer survival, suggesting its role as a prognostic biomarker. Future studies are needed to confirm this association and to elucidate the exact mechanisms by which PIK3CA mutations affect tumor behavior.

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“…There are many Akt activation phenotypes in cancer and normal cells that potentially explain this protective effect, including oncogene-induced senescence, maintenance of differentiation, and anti-invasive/ antimetastatic phenotypes (11,12,14). Observed in experimental animal models and in human tissues, oncogene-induced senescence is an endogenous tumor suppressor mechanism triggered by replication stress (39).…”

Section: Discussionmentioning

confidence: 99%

PIK3CA Mutation Associates with Improved Outcome in Breast Cancer

Kalinsky

Jacks

Heguy

et al. 2009

Clinical Cancer Research

357

286

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Purpose: In breast cancer, somatic mutations in the PIK3CA gene are common. The prognostic implication of these activating mutations remains uncertain as moderately sized studies have yielded variable outcomes. Our aim was to determine the prognostic implications of PIK3CA mutations in breast cancer. Experimental Design: Archival formalin-fixed paraffin-embedded primary breast tumors, from 590 patients selected for known vital status with a median follow-up of 12.8 years and a tumor >1 cm, were genotyped for PIK3CA mutations. Mutation rates and associations between mutation site and clinicopathologic characteristics were assessed. Progression-free survival, overall survival, and breast cancer-specific survival were examined using Kaplan-Meier or competing risk methodology. Results: PIK3CA mutation is identified in 32.5% of breast cancers. PIK3CA mutation significantly associates with older age at diagnosis, hormone receptor positivity, HER2 negativity, lower tumor grade and stage, and lymph node negativity. Patients with PIK3CA mutated tumors have significant improvement in overall survival (P = 0.03) and breast cancer-specific survival (P = 0.004). Analysis for PIK3CA mutation site-specific associations reveals that the H1047R kinase domain mutation highly associates with node negativity (P = 0.007), whereas helical domain hotspot mutations associate with older age at diagnosis (P = 0.004). Conclusion: This study defines the positive prognostic significance of PIK3CA mutations. This work is clinically relevant, as it will significantly affect the design of clinical trials planned for phosphatidylinositol 3-kinase-targeted therapy. Future work may define a population of older age breast cancer patients in whom therapy can be minimized. (Clin Cancer Res 2009;15(16):5049-59)

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AKT induces senescence in primary esophageal epithelial cells but is permissive for differentiation as revealed in organotypic culture

Cited by 46 publications

References 32 publications

The functional interplay between EGFR overexpression, hTERT activation, and p53 mutation in esophageal epithelial cells with activation of stromal fibroblasts induces tumor development, invasion, and differentiation

The functional interplay between EGFR overexpression, hTERT activation, and p53 mutation in esophageal epithelial cells with activation of stromal fibroblasts induces tumor development, invasion, and differentiation

PIK3CA Mutation Is Associated with a Favorable Prognosis among Patients with Curatively Resected Esophageal Squamous Cell Carcinoma

PIK3CA Mutation Associates with Improved Outcome in Breast Cancer

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