Limits...
Astrocyte elevated gene-1(AEG-1) induces epithelial-mesenchymal transition in lung cancer through activating Wnt/β-catenin signaling.

He W, He S, Wang Z, Shen H, Fang W, Zhang Y, Qian W, Lin M, Yuan J, Wang J, Huang W, Wang L, Ke Z - BMC Cancer (2015)

Bottom Line: In the present study, we demonstrated that astrocyte elevated gene-1(AEG-1) ectopic overexpression promoted EMT, which resulted from the down-regulation of E-cadherin and up-regulation of Vimentin in lung cancer cell lines and clinical lung cancer specimens.Using an orthotopic xenograft-mouse model, we also observed that AEG-1 overexpression in human carcinoma cells led to the development of multiple lymph node metastases and elevated mesenchymal markers such as Vimentin, which is a characteristic of cells in EMT.Furthermore, AEG-1 functioned as a critical protein in the regulation of EMT by directly targeting multiple positive regulators of the Wnt/β-catenin signaling cascade, including GSK-3β and CKIδ.

View Article: PubMed Central - PubMed

Affiliation: Department of Gastrointestinal Surgery, Guangzhou, 510080, Province Guangdong, Peoples' Republic of China. heweiling@mail.sysu.edu.cn.

ABSTRACT

Background: Non-small cell lung cancer (NSCLC) is a highly metastatic cancer with limited therapeutic options, so development of novel therapies that target NSCLC is needed. During the early stage of metastasis, the cancer cells undergo an epithelial-mesenchymal transition (EMT), a phase in which Wnt/β-catenin signaling is known to be involved. Simultaneously, AEG-1 has been demonstrated to activate Wnt-mediated signaling in some malignant tumors.

Methods: Human NSCLC cell lines and xenograft of NSCLC cells in nude mice were used to investigate the effects of AEG-1 on EMT. EMT or Wnt/β-catenin pathway-related proteins were characterized by western blot, immunofluorescence and immunohistochemistry.

Results: In the present study, we demonstrated that astrocyte elevated gene-1(AEG-1) ectopic overexpression promoted EMT, which resulted from the down-regulation of E-cadherin and up-regulation of Vimentin in lung cancer cell lines and clinical lung cancer specimens. Using an orthotopic xenograft-mouse model, we also observed that AEG-1 overexpression in human carcinoma cells led to the development of multiple lymph node metastases and elevated mesenchymal markers such as Vimentin, which is a characteristic of cells in EMT. Furthermore, AEG-1 functioned as a critical protein in the regulation of EMT by directly targeting multiple positive regulators of the Wnt/β-catenin signaling cascade, including GSK-3β and CKIδ. Notably, overexpression of AEG-1 in metastatic cancer tissues was closely associated with poor survival of NSCLC patients.

Conclusions: These results reveal the critical role of AEG-1 in EMT and suggest that AEG-1 may be a prognostic biomarker and its targeted inhibition may be utilized as a novel therapy for NSCLC.

Show MeSH

Related in: MedlinePlus

AEG-1 promoted Wnt-mediated EMT. Knockdown of AEG-1 activated GSK-3β, and inhibited β-catenin activity and EMT in NCI-H226 cells. Cells were co-transfected with AEG-1-siRNA and TOP or FOP. Then, cells were treated with Wnt-CM. (A) The expression of the indicated proteins was analyzed by Western blot in NCI-H226 (control siRNA) and AEG-1-siRNA with or without Wnt-3a-CM, respectively. (B) Relative luciferase expression of β-catenin was measured as described above. (C) and (D) In contrast, restoring AEG-1 expression in Slu-01 cells (AEG-1-negative) promoted Wnt-induced EMT.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4358870&req=5

Fig4: AEG-1 promoted Wnt-mediated EMT. Knockdown of AEG-1 activated GSK-3β, and inhibited β-catenin activity and EMT in NCI-H226 cells. Cells were co-transfected with AEG-1-siRNA and TOP or FOP. Then, cells were treated with Wnt-CM. (A) The expression of the indicated proteins was analyzed by Western blot in NCI-H226 (control siRNA) and AEG-1-siRNA with or without Wnt-3a-CM, respectively. (B) Relative luciferase expression of β-catenin was measured as described above. (C) and (D) In contrast, restoring AEG-1 expression in Slu-01 cells (AEG-1-negative) promoted Wnt-induced EMT.

Mentions: Wnt/β-catenin signaling has been demonstrated to participate in the EMT process during embryonic development and cancer progression; however, the involvement of AEG-1 in Wnt/β-catenin-mediated EMT has not been completely defined. To address this question, we tested whether manipulating AEG-1 levels in various cell lines would be able to convert the mesenchymal phenotypes. Whereas Wnt-3a only slightly induced EMT in NCI-H226, AEG-1 depletion notably elicited a change in NCI-H226 cells from the mesenchymal phenotype to an epithelial phenotype as manifested by increased expression of the epithelial marker E-cadherin concomitant with a downregulation of the mesenchymal marker Vimentin (Figure 4A). Similarly, the knockdown of AEG-1 also resulted in the decrease of the p-GSK-3β level and reduced β-catenin/TCF transcriptional activity (Figure 4B).Figure 4


Astrocyte elevated gene-1(AEG-1) induces epithelial-mesenchymal transition in lung cancer through activating Wnt/β-catenin signaling.

He W, He S, Wang Z, Shen H, Fang W, Zhang Y, Qian W, Lin M, Yuan J, Wang J, Huang W, Wang L, Ke Z - BMC Cancer (2015)

AEG-1 promoted Wnt-mediated EMT. Knockdown of AEG-1 activated GSK-3β, and inhibited β-catenin activity and EMT in NCI-H226 cells. Cells were co-transfected with AEG-1-siRNA and TOP or FOP. Then, cells were treated with Wnt-CM. (A) The expression of the indicated proteins was analyzed by Western blot in NCI-H226 (control siRNA) and AEG-1-siRNA with or without Wnt-3a-CM, respectively. (B) Relative luciferase expression of β-catenin was measured as described above. (C) and (D) In contrast, restoring AEG-1 expression in Slu-01 cells (AEG-1-negative) promoted Wnt-induced EMT.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4358870&req=5

Fig4: AEG-1 promoted Wnt-mediated EMT. Knockdown of AEG-1 activated GSK-3β, and inhibited β-catenin activity and EMT in NCI-H226 cells. Cells were co-transfected with AEG-1-siRNA and TOP or FOP. Then, cells were treated with Wnt-CM. (A) The expression of the indicated proteins was analyzed by Western blot in NCI-H226 (control siRNA) and AEG-1-siRNA with or without Wnt-3a-CM, respectively. (B) Relative luciferase expression of β-catenin was measured as described above. (C) and (D) In contrast, restoring AEG-1 expression in Slu-01 cells (AEG-1-negative) promoted Wnt-induced EMT.
Mentions: Wnt/β-catenin signaling has been demonstrated to participate in the EMT process during embryonic development and cancer progression; however, the involvement of AEG-1 in Wnt/β-catenin-mediated EMT has not been completely defined. To address this question, we tested whether manipulating AEG-1 levels in various cell lines would be able to convert the mesenchymal phenotypes. Whereas Wnt-3a only slightly induced EMT in NCI-H226, AEG-1 depletion notably elicited a change in NCI-H226 cells from the mesenchymal phenotype to an epithelial phenotype as manifested by increased expression of the epithelial marker E-cadherin concomitant with a downregulation of the mesenchymal marker Vimentin (Figure 4A). Similarly, the knockdown of AEG-1 also resulted in the decrease of the p-GSK-3β level and reduced β-catenin/TCF transcriptional activity (Figure 4B).Figure 4

Bottom Line: In the present study, we demonstrated that astrocyte elevated gene-1(AEG-1) ectopic overexpression promoted EMT, which resulted from the down-regulation of E-cadherin and up-regulation of Vimentin in lung cancer cell lines and clinical lung cancer specimens.Using an orthotopic xenograft-mouse model, we also observed that AEG-1 overexpression in human carcinoma cells led to the development of multiple lymph node metastases and elevated mesenchymal markers such as Vimentin, which is a characteristic of cells in EMT.Furthermore, AEG-1 functioned as a critical protein in the regulation of EMT by directly targeting multiple positive regulators of the Wnt/β-catenin signaling cascade, including GSK-3β and CKIδ.

View Article: PubMed Central - PubMed

Affiliation: Department of Gastrointestinal Surgery, Guangzhou, 510080, Province Guangdong, Peoples' Republic of China. heweiling@mail.sysu.edu.cn.

ABSTRACT

Background: Non-small cell lung cancer (NSCLC) is a highly metastatic cancer with limited therapeutic options, so development of novel therapies that target NSCLC is needed. During the early stage of metastasis, the cancer cells undergo an epithelial-mesenchymal transition (EMT), a phase in which Wnt/β-catenin signaling is known to be involved. Simultaneously, AEG-1 has been demonstrated to activate Wnt-mediated signaling in some malignant tumors.

Methods: Human NSCLC cell lines and xenograft of NSCLC cells in nude mice were used to investigate the effects of AEG-1 on EMT. EMT or Wnt/β-catenin pathway-related proteins were characterized by western blot, immunofluorescence and immunohistochemistry.

Results: In the present study, we demonstrated that astrocyte elevated gene-1(AEG-1) ectopic overexpression promoted EMT, which resulted from the down-regulation of E-cadherin and up-regulation of Vimentin in lung cancer cell lines and clinical lung cancer specimens. Using an orthotopic xenograft-mouse model, we also observed that AEG-1 overexpression in human carcinoma cells led to the development of multiple lymph node metastases and elevated mesenchymal markers such as Vimentin, which is a characteristic of cells in EMT. Furthermore, AEG-1 functioned as a critical protein in the regulation of EMT by directly targeting multiple positive regulators of the Wnt/β-catenin signaling cascade, including GSK-3β and CKIδ. Notably, overexpression of AEG-1 in metastatic cancer tissues was closely associated with poor survival of NSCLC patients.

Conclusions: These results reveal the critical role of AEG-1 in EMT and suggest that AEG-1 may be a prognostic biomarker and its targeted inhibition may be utilized as a novel therapy for NSCLC.

Show MeSH
Related in: MedlinePlus