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XPC inhibits NSCLC cell proliferation and migration by enhancing E-Cadherin expression.

Cui T, Srivastava AK, Han C, Yang L, Zhao R, Zou N, Qu M, Duan W, Zhang X, Wang QE - Oncotarget (2015)

Bottom Line: Deletion of XPC is associated with early stages of human lung carcinogenesis, and reduced XPC mRNA levels predict poor patient outcome for non-small cell lung cancer (NSCLC).Restoration of E-Cadherin in these cells suppressed XPC knockdown-induced cell growth both in vitro and in vivo.Mechanistic studies showed that the loss of XPC repressed E-Cadherin expression by activating the ERK pathway and upregulating Snail expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.

ABSTRACT
Xeroderma pigmentosum complementation group C (XPC) protein is an important DNA damage recognition factor in nucleotide excision repair. Deletion of XPC is associated with early stages of human lung carcinogenesis, and reduced XPC mRNA levels predict poor patient outcome for non-small cell lung cancer (NSCLC). However, the mechanisms linking loss of XPC expression and poor prognosis in lung cancer are still unclear. Here, we report evidence that XPC silencing drives proliferation and migration of NSCLC cells by down-regulating E-Cadherin. XPC knockdown enhanced proliferation and migration while decreasing E-Cadherin expression in NSCLC cells with an epithelial phenotype. Restoration of E-Cadherin in these cells suppressed XPC knockdown-induced cell growth both in vitro and in vivo. Mechanistic studies showed that the loss of XPC repressed E-Cadherin expression by activating the ERK pathway and upregulating Snail expression. Our findings indicate that XPC silencing-induced reduction of E-Cadherin expression contributes, at least in part, to the poor outcome of NSCLC patients with low XPC expression.

No MeSH data available.


Related in: MedlinePlus

XPC regulates the expression of E-Cadherin in NSCLC cells(A) Paired expression of XPC and E-Cadherin were immunohistochemically examined on the lung cancer tissue microarray (Scale bar: 50 μm). (B) Positive correlation between XPC and E-Cadherin protein expression in human lung tumor tissues (n = 70, P = 0.005). Negative and positive expression was defined in the Materials and Methods. (C-E) qRT-PCR was conducted to determine the mRNA expression levels of XPC and E-Cadherin in A549 and H1650 cells after being transfected with either siRNA or shRNA specific to the human XPC gene. n = 3, bar: SD, *, P < 0.05; **, P < 0.01. (F-H) Immunoblotting analysis was conducted to determine the protein expression of E-Cadherin in A549 and H1650 cells after being transfected with siXPC or shXPC. The intensity of each band was quantified using ImageJ and normalized to Lamin B and then to their corresponding siCtrl/shCtrl-transfected cells.
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Figure 2: XPC regulates the expression of E-Cadherin in NSCLC cells(A) Paired expression of XPC and E-Cadherin were immunohistochemically examined on the lung cancer tissue microarray (Scale bar: 50 μm). (B) Positive correlation between XPC and E-Cadherin protein expression in human lung tumor tissues (n = 70, P = 0.005). Negative and positive expression was defined in the Materials and Methods. (C-E) qRT-PCR was conducted to determine the mRNA expression levels of XPC and E-Cadherin in A549 and H1650 cells after being transfected with either siRNA or shRNA specific to the human XPC gene. n = 3, bar: SD, *, P < 0.05; **, P < 0.01. (F-H) Immunoblotting analysis was conducted to determine the protein expression of E-Cadherin in A549 and H1650 cells after being transfected with siXPC or shXPC. The intensity of each band was quantified using ImageJ and normalized to Lamin B and then to their corresponding siCtrl/shCtrl-transfected cells.

Mentions: E-Cadherin is an important cell growth inhibitor [23]. Given that our data indicate XPC regulates cell growth in E-Cadherin expressing cells, we attempted to understand whether XPC regulates the expression of E-Cadherin. Analysis of TCGA data by cBioPortal (http://www.cbioportal.org/public-portal/) demonstrated a positive correlation between XPC mRNA expression and E-Cadherin protein expression levels in NSCLC (Supplementary Figure 5). We confirmed this correlation at the protein level by analyzing tissue microarrays that contained 70 lung tumor tissues. Immunohistochemical staining revealed a significant positive correlation between the expression of XPC and E-Cadherin proteins from the same patients (Figures 2A-B). To further investigate the role of XPC in the regulation of E-Cadherin expression, we downregulated XPC expression in A549 and H1650 cells using either siRNA or shRNA specific to the human XPC gene, and analyzed the expression of E-Cadherin at both mRNA and protein levels. As shown in Figures 2C-H, knockdown of XPC consistently decreased E-Cadherin expression at both transcript and protein levels, and this positive regulatory role could be confirmed in at least two NSCLC cell lines with siRNA/shRNA targeting different sequences of the XPC gene. Taken together, these results indicate that expression of E-Cadherin can be positively regulated by XPC in human NSCLC.


XPC inhibits NSCLC cell proliferation and migration by enhancing E-Cadherin expression.

Cui T, Srivastava AK, Han C, Yang L, Zhao R, Zou N, Qu M, Duan W, Zhang X, Wang QE - Oncotarget (2015)

XPC regulates the expression of E-Cadherin in NSCLC cells(A) Paired expression of XPC and E-Cadherin were immunohistochemically examined on the lung cancer tissue microarray (Scale bar: 50 μm). (B) Positive correlation between XPC and E-Cadherin protein expression in human lung tumor tissues (n = 70, P = 0.005). Negative and positive expression was defined in the Materials and Methods. (C-E) qRT-PCR was conducted to determine the mRNA expression levels of XPC and E-Cadherin in A549 and H1650 cells after being transfected with either siRNA or shRNA specific to the human XPC gene. n = 3, bar: SD, *, P < 0.05; **, P < 0.01. (F-H) Immunoblotting analysis was conducted to determine the protein expression of E-Cadherin in A549 and H1650 cells after being transfected with siXPC or shXPC. The intensity of each band was quantified using ImageJ and normalized to Lamin B and then to their corresponding siCtrl/shCtrl-transfected cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496340&req=5

Figure 2: XPC regulates the expression of E-Cadherin in NSCLC cells(A) Paired expression of XPC and E-Cadherin were immunohistochemically examined on the lung cancer tissue microarray (Scale bar: 50 μm). (B) Positive correlation between XPC and E-Cadherin protein expression in human lung tumor tissues (n = 70, P = 0.005). Negative and positive expression was defined in the Materials and Methods. (C-E) qRT-PCR was conducted to determine the mRNA expression levels of XPC and E-Cadherin in A549 and H1650 cells after being transfected with either siRNA or shRNA specific to the human XPC gene. n = 3, bar: SD, *, P < 0.05; **, P < 0.01. (F-H) Immunoblotting analysis was conducted to determine the protein expression of E-Cadherin in A549 and H1650 cells after being transfected with siXPC or shXPC. The intensity of each band was quantified using ImageJ and normalized to Lamin B and then to their corresponding siCtrl/shCtrl-transfected cells.
Mentions: E-Cadherin is an important cell growth inhibitor [23]. Given that our data indicate XPC regulates cell growth in E-Cadherin expressing cells, we attempted to understand whether XPC regulates the expression of E-Cadherin. Analysis of TCGA data by cBioPortal (http://www.cbioportal.org/public-portal/) demonstrated a positive correlation between XPC mRNA expression and E-Cadherin protein expression levels in NSCLC (Supplementary Figure 5). We confirmed this correlation at the protein level by analyzing tissue microarrays that contained 70 lung tumor tissues. Immunohistochemical staining revealed a significant positive correlation between the expression of XPC and E-Cadherin proteins from the same patients (Figures 2A-B). To further investigate the role of XPC in the regulation of E-Cadherin expression, we downregulated XPC expression in A549 and H1650 cells using either siRNA or shRNA specific to the human XPC gene, and analyzed the expression of E-Cadherin at both mRNA and protein levels. As shown in Figures 2C-H, knockdown of XPC consistently decreased E-Cadherin expression at both transcript and protein levels, and this positive regulatory role could be confirmed in at least two NSCLC cell lines with siRNA/shRNA targeting different sequences of the XPC gene. Taken together, these results indicate that expression of E-Cadherin can be positively regulated by XPC in human NSCLC.

Bottom Line: Deletion of XPC is associated with early stages of human lung carcinogenesis, and reduced XPC mRNA levels predict poor patient outcome for non-small cell lung cancer (NSCLC).Restoration of E-Cadherin in these cells suppressed XPC knockdown-induced cell growth both in vitro and in vivo.Mechanistic studies showed that the loss of XPC repressed E-Cadherin expression by activating the ERK pathway and upregulating Snail expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.

ABSTRACT
Xeroderma pigmentosum complementation group C (XPC) protein is an important DNA damage recognition factor in nucleotide excision repair. Deletion of XPC is associated with early stages of human lung carcinogenesis, and reduced XPC mRNA levels predict poor patient outcome for non-small cell lung cancer (NSCLC). However, the mechanisms linking loss of XPC expression and poor prognosis in lung cancer are still unclear. Here, we report evidence that XPC silencing drives proliferation and migration of NSCLC cells by down-regulating E-Cadherin. XPC knockdown enhanced proliferation and migration while decreasing E-Cadherin expression in NSCLC cells with an epithelial phenotype. Restoration of E-Cadherin in these cells suppressed XPC knockdown-induced cell growth both in vitro and in vivo. Mechanistic studies showed that the loss of XPC repressed E-Cadherin expression by activating the ERK pathway and upregulating Snail expression. Our findings indicate that XPC silencing-induced reduction of E-Cadherin expression contributes, at least in part, to the poor outcome of NSCLC patients with low XPC expression.

No MeSH data available.


Related in: MedlinePlus