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Relevance and therapeutic possibility of PTEN-long in renal cell carcinoma.

Wang H, Zhang P, Lin C, Yu Q, Wu J, Wang L, Cui Y, Wang K, Gao Z, Li H - PLoS ONE (2015)

Bottom Line: We found that the protein levels of PTEN-Long were drastically reduced in ccRCC, which was correlated with increased levels of phosphorylated Akt (pAkt).When purified PTEN-Long was added into cultured 786-0 cells, it entered cells, blocked Akt activation, and induced apoptosis involving Caspase 3 cleavage.Furthermore, PTEN-Long inhibited proliferation of 786-0 cells in xenograft mouse model.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University Medical College, Institute of Urology, Zhifu, Yantai, Shandong, 264000, People's Republic of China.

ABSTRACT
PTEN-Long is a translational variant of PTEN (Phosphatase and Tensin Homolog). Like PTEN, PTEN-Long is able to antagonize the PI3K-Akt pathway and inhibits tumor growth. In this study, we investigated the role PTEN-Long plays in the development and progression of clear cell renal cell carcinoma (ccRCC) and explored the therapeutic possibility using proteinaceous PTEN-Long to treat ccRCC. We found that the protein levels of PTEN-Long were drastically reduced in ccRCC, which was correlated with increased levels of phosphorylated Akt (pAkt). Gain of function experiments showed overexpression of PTEN-Long in the ccRCC cell line 786-0 suppressed PI3K-Akt signaling, inhibited cell proliferation, migration and invasion, and eventually induced cell death. When purified PTEN-Long was added into cultured 786-0 cells, it entered cells, blocked Akt activation, and induced apoptosis involving Caspase 3 cleavage. Furthermore, PTEN-Long inhibited proliferation of 786-0 cells in xenograft mouse model. Our results implicated that understanding the roles of PTEN-Long in renal cell carcinogenesis has therapeutic significance.

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Related in: MedlinePlus

Entry of PTEN-Long into 786-0 cells.A, 786-0 cells treated with 100 nM purified PTEN-Long-GFP or PTEN-GFP for 5 h and imaged, showing PTEN-Long-GFP but not PTEN-GFP entered 786-0 cells. The scale bar represents 10 µm. B, Immunoprecipitation for PTEN on cell lysates pretreated with PTEN-Long or PTEN followed by Western blotting analysis with antibody against PTEN, showing only PTEN-Long was detected.
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pone-0114250-g006: Entry of PTEN-Long into 786-0 cells.A, 786-0 cells treated with 100 nM purified PTEN-Long-GFP or PTEN-GFP for 5 h and imaged, showing PTEN-Long-GFP but not PTEN-GFP entered 786-0 cells. The scale bar represents 10 µm. B, Immunoprecipitation for PTEN on cell lysates pretreated with PTEN-Long or PTEN followed by Western blotting analysis with antibody against PTEN, showing only PTEN-Long was detected.

Mentions: Previously, Parsons and colleagues reported an evolutionarily conserved poly-arginine stretch, similar to that in the cell-penetrating transactivator of transcription (TAT) protein from HIV, was present in the PTEN-Long N-terminal domain. This gives PTEN-Long the ability to enter cells. To test whether PTEN-Long entered 786-0 cells to execute killing function, we attached a green fluorescence protein (GFP) tag to the C-terminal of PTEN-Long and PTEN. 786-0 cells were treated with 100 nM purified PTEN-Long-GFP or PTEN-GFP for 5 h. Cells were washed, fixed, and imaged under fluorescence microscope. GFP signal was only detected from 786-0 cells pre-treated with PTEN-Long-GFP but not PTEN-GFP, indicating only PTEN-Long entered cells (Fig. 6A). To confirm this observation, we concentrated PTEN or PTEN-Long from cell lysate by immunoprecipitation with antibody against PTEN and analyzed by Western blotting, which showed only PTEN-Long was detected (Fig. 6B, upper panel).


Relevance and therapeutic possibility of PTEN-long in renal cell carcinoma.

Wang H, Zhang P, Lin C, Yu Q, Wu J, Wang L, Cui Y, Wang K, Gao Z, Li H - PLoS ONE (2015)

Entry of PTEN-Long into 786-0 cells.A, 786-0 cells treated with 100 nM purified PTEN-Long-GFP or PTEN-GFP for 5 h and imaged, showing PTEN-Long-GFP but not PTEN-GFP entered 786-0 cells. The scale bar represents 10 µm. B, Immunoprecipitation for PTEN on cell lysates pretreated with PTEN-Long or PTEN followed by Western blotting analysis with antibody against PTEN, showing only PTEN-Long was detected.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4340966&req=5

pone-0114250-g006: Entry of PTEN-Long into 786-0 cells.A, 786-0 cells treated with 100 nM purified PTEN-Long-GFP or PTEN-GFP for 5 h and imaged, showing PTEN-Long-GFP but not PTEN-GFP entered 786-0 cells. The scale bar represents 10 µm. B, Immunoprecipitation for PTEN on cell lysates pretreated with PTEN-Long or PTEN followed by Western blotting analysis with antibody against PTEN, showing only PTEN-Long was detected.
Mentions: Previously, Parsons and colleagues reported an evolutionarily conserved poly-arginine stretch, similar to that in the cell-penetrating transactivator of transcription (TAT) protein from HIV, was present in the PTEN-Long N-terminal domain. This gives PTEN-Long the ability to enter cells. To test whether PTEN-Long entered 786-0 cells to execute killing function, we attached a green fluorescence protein (GFP) tag to the C-terminal of PTEN-Long and PTEN. 786-0 cells were treated with 100 nM purified PTEN-Long-GFP or PTEN-GFP for 5 h. Cells were washed, fixed, and imaged under fluorescence microscope. GFP signal was only detected from 786-0 cells pre-treated with PTEN-Long-GFP but not PTEN-GFP, indicating only PTEN-Long entered cells (Fig. 6A). To confirm this observation, we concentrated PTEN or PTEN-Long from cell lysate by immunoprecipitation with antibody against PTEN and analyzed by Western blotting, which showed only PTEN-Long was detected (Fig. 6B, upper panel).

Bottom Line: We found that the protein levels of PTEN-Long were drastically reduced in ccRCC, which was correlated with increased levels of phosphorylated Akt (pAkt).When purified PTEN-Long was added into cultured 786-0 cells, it entered cells, blocked Akt activation, and induced apoptosis involving Caspase 3 cleavage.Furthermore, PTEN-Long inhibited proliferation of 786-0 cells in xenograft mouse model.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University Medical College, Institute of Urology, Zhifu, Yantai, Shandong, 264000, People's Republic of China.

ABSTRACT
PTEN-Long is a translational variant of PTEN (Phosphatase and Tensin Homolog). Like PTEN, PTEN-Long is able to antagonize the PI3K-Akt pathway and inhibits tumor growth. In this study, we investigated the role PTEN-Long plays in the development and progression of clear cell renal cell carcinoma (ccRCC) and explored the therapeutic possibility using proteinaceous PTEN-Long to treat ccRCC. We found that the protein levels of PTEN-Long were drastically reduced in ccRCC, which was correlated with increased levels of phosphorylated Akt (pAkt). Gain of function experiments showed overexpression of PTEN-Long in the ccRCC cell line 786-0 suppressed PI3K-Akt signaling, inhibited cell proliferation, migration and invasion, and eventually induced cell death. When purified PTEN-Long was added into cultured 786-0 cells, it entered cells, blocked Akt activation, and induced apoptosis involving Caspase 3 cleavage. Furthermore, PTEN-Long inhibited proliferation of 786-0 cells in xenograft mouse model. Our results implicated that understanding the roles of PTEN-Long in renal cell carcinogenesis has therapeutic significance.

Show MeSH
Related in: MedlinePlus