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Nuclear Receptor Expression and Function in Human Lung Cancer Pathogenesis.

Kim J, Sato M, Choi JW, Kim HW, Yeh BI, Larsen JE, Minna JD, Cha JH, Jeong Y - PLoS ONE (2015)

Bottom Line: Notably, PPARγ activation by thiazolidinedione (TZD) treatment reversed the increased expression of pro-inflammatory cyclooxygenase 2 (COX2) in precancerous HBECs.In fully tumorigenic HBECs with inducible expression of PPARγ, TZD treatments inhibited tumor cell growth, clonogenecity, and cell migration in a PPARγ-sumoylation dependent manner.Mechanistically, the sumoylation of liganded-PPARγ decreased COX2 expression and increased 15-hydroxyprostaglandin dehydrogenase expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Wonju College of Medicine, Yonsei University, Wonju, Gangwon-do, Republic of Korea; Institute of Lifestyle Medicine, Wonju College of Medicine, Yonsei University, Wonju, Gangwon-do, Republic of Korea; Nuclear Receptor Research Consortium, Wonju College of Medicine, Yonsei University, Wonju, Gangwon-do, Republic of Korea.

ABSTRACT
Lung cancer is caused by combinations of diverse genetic mutations. Here, to understand the relevance of nuclear receptors (NRs) in the oncogene-associated lung cancer pathogenesis, we investigated the expression profile of the entire 48 NR members by using QPCR analysis in a panel of human bronchial epithelial cells (HBECs) that included precancerous and tumorigenic HBECs harboring oncogenic K-rasV12 and/or p53 alterations. The analysis of the profile revealed that oncogenic alterations accompanied transcriptional changes in the expression of 19 NRs in precancerous HBECs and 15 NRs according to the malignant progression of HBECs. Amongst these, peroxisome proliferator-activated receptor gamma (PPARγ), a NR chosen as a proof-of-principle study, showed increased expression in precancerous HBECs, which was surprisingly reversed when these HBECs acquired full in vivo tumorigenicity. Notably, PPARγ activation by thiazolidinedione (TZD) treatment reversed the increased expression of pro-inflammatory cyclooxygenase 2 (COX2) in precancerous HBECs. In fully tumorigenic HBECs with inducible expression of PPARγ, TZD treatments inhibited tumor cell growth, clonogenecity, and cell migration in a PPARγ-sumoylation dependent manner. Mechanistically, the sumoylation of liganded-PPARγ decreased COX2 expression and increased 15-hydroxyprostaglandin dehydrogenase expression. This suggests that ligand-mediated sumoylation of PPARγ plays an important role in lung cancer pathogenesis by modulating prostaglandin metabolism.

No MeSH data available.


Related in: MedlinePlus

Characterization of human bronchial epithelial cells.(A) Schematics to generate a panel of HBEC cells. (B, C) In vitro characterization of HBECs. (B) Immunoblot assays were performed for the expression of K-rasV12, p53, pMEK, total MEK, and beta-actin in HBEC cells. (C) A microscopic view of HBEC cells (magnification, 1x). Note that HBEC-KT stands for HBEC cell lines immortalized by CDK4 plus hTERt; KTRL, KT plus oncogenic K-rasV12; KT53, KT plus p53 knock-down; KTRL53, KTRL plus p53 knock-down.
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pone.0134842.g001: Characterization of human bronchial epithelial cells.(A) Schematics to generate a panel of HBEC cells. (B, C) In vitro characterization of HBECs. (B) Immunoblot assays were performed for the expression of K-rasV12, p53, pMEK, total MEK, and beta-actin in HBEC cells. (C) A microscopic view of HBEC cells (magnification, 1x). Note that HBEC-KT stands for HBEC cell lines immortalized by CDK4 plus hTERt; KTRL, KT plus oncogenic K-rasV12; KT53, KT plus p53 knock-down; KTRL53, KTRL plus p53 knock-down.

Mentions: The overall schema for generating immortalized and tumorigenic HBECs is shown in Fig 1A. To understand the effect of oncogenic alterations on the tumorigenic potential of bronchial epithelial cells, we previously generated a panel of immortalized HBECs harboring either K-rasV12 expression, p53 knockdown, or both changes, which are major mutations in lung cancer [32, 33]. Using a mouse xenograft model, HBEC clones, C1 and C5, were identified to be tumorigenic and characterized. Stable knockdown of p53 was confirmed for both mRNA and protein expression using QPCR assay and immunoblot analysis, respectively (Fig 1B and S1 Fig). The activity of oncogenic K-rasV12 stably introduced into the immortalized HBEC cell lines was confirmed by phosphorylation of MEK, a downstream target kinase of K-ras (Fig 1B). These genetic changes clearly induced a vacuole-like cellular morphological change that appeared to be cellular senescence, which is consistent with results from a previous report [31] (Fig 1C).


Nuclear Receptor Expression and Function in Human Lung Cancer Pathogenesis.

Kim J, Sato M, Choi JW, Kim HW, Yeh BI, Larsen JE, Minna JD, Cha JH, Jeong Y - PLoS ONE (2015)

Characterization of human bronchial epithelial cells.(A) Schematics to generate a panel of HBEC cells. (B, C) In vitro characterization of HBECs. (B) Immunoblot assays were performed for the expression of K-rasV12, p53, pMEK, total MEK, and beta-actin in HBEC cells. (C) A microscopic view of HBEC cells (magnification, 1x). Note that HBEC-KT stands for HBEC cell lines immortalized by CDK4 plus hTERt; KTRL, KT plus oncogenic K-rasV12; KT53, KT plus p53 knock-down; KTRL53, KTRL plus p53 knock-down.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526668&req=5

pone.0134842.g001: Characterization of human bronchial epithelial cells.(A) Schematics to generate a panel of HBEC cells. (B, C) In vitro characterization of HBECs. (B) Immunoblot assays were performed for the expression of K-rasV12, p53, pMEK, total MEK, and beta-actin in HBEC cells. (C) A microscopic view of HBEC cells (magnification, 1x). Note that HBEC-KT stands for HBEC cell lines immortalized by CDK4 plus hTERt; KTRL, KT plus oncogenic K-rasV12; KT53, KT plus p53 knock-down; KTRL53, KTRL plus p53 knock-down.
Mentions: The overall schema for generating immortalized and tumorigenic HBECs is shown in Fig 1A. To understand the effect of oncogenic alterations on the tumorigenic potential of bronchial epithelial cells, we previously generated a panel of immortalized HBECs harboring either K-rasV12 expression, p53 knockdown, or both changes, which are major mutations in lung cancer [32, 33]. Using a mouse xenograft model, HBEC clones, C1 and C5, were identified to be tumorigenic and characterized. Stable knockdown of p53 was confirmed for both mRNA and protein expression using QPCR assay and immunoblot analysis, respectively (Fig 1B and S1 Fig). The activity of oncogenic K-rasV12 stably introduced into the immortalized HBEC cell lines was confirmed by phosphorylation of MEK, a downstream target kinase of K-ras (Fig 1B). These genetic changes clearly induced a vacuole-like cellular morphological change that appeared to be cellular senescence, which is consistent with results from a previous report [31] (Fig 1C).

Bottom Line: Notably, PPARγ activation by thiazolidinedione (TZD) treatment reversed the increased expression of pro-inflammatory cyclooxygenase 2 (COX2) in precancerous HBECs.In fully tumorigenic HBECs with inducible expression of PPARγ, TZD treatments inhibited tumor cell growth, clonogenecity, and cell migration in a PPARγ-sumoylation dependent manner.Mechanistically, the sumoylation of liganded-PPARγ decreased COX2 expression and increased 15-hydroxyprostaglandin dehydrogenase expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Wonju College of Medicine, Yonsei University, Wonju, Gangwon-do, Republic of Korea; Institute of Lifestyle Medicine, Wonju College of Medicine, Yonsei University, Wonju, Gangwon-do, Republic of Korea; Nuclear Receptor Research Consortium, Wonju College of Medicine, Yonsei University, Wonju, Gangwon-do, Republic of Korea.

ABSTRACT
Lung cancer is caused by combinations of diverse genetic mutations. Here, to understand the relevance of nuclear receptors (NRs) in the oncogene-associated lung cancer pathogenesis, we investigated the expression profile of the entire 48 NR members by using QPCR analysis in a panel of human bronchial epithelial cells (HBECs) that included precancerous and tumorigenic HBECs harboring oncogenic K-rasV12 and/or p53 alterations. The analysis of the profile revealed that oncogenic alterations accompanied transcriptional changes in the expression of 19 NRs in precancerous HBECs and 15 NRs according to the malignant progression of HBECs. Amongst these, peroxisome proliferator-activated receptor gamma (PPARγ), a NR chosen as a proof-of-principle study, showed increased expression in precancerous HBECs, which was surprisingly reversed when these HBECs acquired full in vivo tumorigenicity. Notably, PPARγ activation by thiazolidinedione (TZD) treatment reversed the increased expression of pro-inflammatory cyclooxygenase 2 (COX2) in precancerous HBECs. In fully tumorigenic HBECs with inducible expression of PPARγ, TZD treatments inhibited tumor cell growth, clonogenecity, and cell migration in a PPARγ-sumoylation dependent manner. Mechanistically, the sumoylation of liganded-PPARγ decreased COX2 expression and increased 15-hydroxyprostaglandin dehydrogenase expression. This suggests that ligand-mediated sumoylation of PPARγ plays an important role in lung cancer pathogenesis by modulating prostaglandin metabolism.

No MeSH data available.


Related in: MedlinePlus