Limits...
Knockdown of a novel lincRNA AATBC suppresses proliferation and induces apoptosis in bladder cancer.

Zhao F, Lin T, He W, Han J, Zhu D, Hu K, Li W, Zheng Z, Huang J, Xie W - Oncotarget (2015)

Bottom Line: We also found that inhibition of AATBC resulted in cell proliferation arrest through G1 cell cycle mediated by cyclin D1, CDK4, p18 and phosphorylated Rb.Furthermore, JNK inhibitor SP600125 could attenuate the apoptotic effect achieved by AATBC knockdown, confirming the involvement of JNK signaling in the induced apoptosis.Moreover, mouse xenograft model revealed that knockdown of AATBC led to suppress tumorigenesis in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.

ABSTRACT
Long intergenic noncoding RNAs (lincRNAs) play important roles in regulating various biological processes in cancer, including proliferation and apoptosis. However, the roles of lincRNAs in bladder cancer remain elusive. In this study, we identified a novel lincRNA, which we termed AATBC. We found that AATBC was overexpressed in bladder cancer patient tissues and positively correlated with tumor grade and pT stage. We also found that inhibition of AATBC resulted in cell proliferation arrest through G1 cell cycle mediated by cyclin D1, CDK4, p18 and phosphorylated Rb. In addition, inhibition of AATBC induced cell apoptosis through the intrinsic apoptosis signaling pathway, as evidenced by the activation of caspase-9 and caspase-3. The investigation for the signaling pathway revealed that the apoptosis following AATBC knockdown was mediated by activation of phosphorylated JNK and suppression of NRF2. Furthermore, JNK inhibitor SP600125 could attenuate the apoptotic effect achieved by AATBC knockdown, confirming the involvement of JNK signaling in the induced apoptosis. Moreover, mouse xenograft model revealed that knockdown of AATBC led to suppress tumorigenesis in vivo. Taken together, our study indicated that AATBC might play a critical role in pro-proliferation and anti-apoptosis in bladder cancer by regulating cell cycle, intrinsic apoptosis signaling, JNK signaling and NRF2. AATBC could be a potential therapeutic target and molecular biomarker for bladder cancer.

Show MeSH

Related in: MedlinePlus

Effect of AATBC knockdown on bladder cancer apoptosisA. 48 hours after transfection, apoptosis rate in UM-UC-3 cells was analyzed by flow cytometry. In cisplatin-induced groups, cisplatin was added 24 hours before examination. Data represented as means ± SD. *P < 0.05 (vs. control). B. 48 hours after transfection, apoptotic rate in EJ cells was analyzed by flow cytometry. In cisplatin-induced groups, cisplatin was added 24 hours before examination. Data represented as means ± SD.*P < 0.05 (vs. control). C. Western blotting was used to detect the expression of caspase-9, caspase-3 and PARP. β-tubulin served as loading control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4359217&req=5

Figure 5: Effect of AATBC knockdown on bladder cancer apoptosisA. 48 hours after transfection, apoptosis rate in UM-UC-3 cells was analyzed by flow cytometry. In cisplatin-induced groups, cisplatin was added 24 hours before examination. Data represented as means ± SD. *P < 0.05 (vs. control). B. 48 hours after transfection, apoptotic rate in EJ cells was analyzed by flow cytometry. In cisplatin-induced groups, cisplatin was added 24 hours before examination. Data represented as means ± SD.*P < 0.05 (vs. control). C. Western blotting was used to detect the expression of caspase-9, caspase-3 and PARP. β-tubulin served as loading control.

Mentions: We then investigated the involvement of AATBC in cell death of bladder cancer cells through inhibiting AATBC expression with siRNAs. As shown by flow cytometry analysis in Fig. 5A-B, siRNAs treatment led to the increased apoptotic rates in UM-UC-3 and EJ cells compared with that in negative control groups. After cells were induced with cisplatin, the pro-apoptotic effect of AATBC inhibition was augmented significantly when compared to that of no cisplatin-induced groups. Western blotting was used to investigate the alteration of apoptosis-related proteins induced by AATBC down-regulation. To our knowledge, the cleavages of caspase-9 and caspase-3 are prominent markers of the intrinsic apoptosis. In this present study, the occurrence and intensity of apoptosis resulted from AATBC knockdown were evidenced by the enhanced cleavages of poly (ADP-ribose) polymerase (PARP), caspase-9 and caspase-3 in both UM-UC-3 and EJ cell lines (Fig. 5C), indicating that the activation of intrinsic apoptotic pathway was involved in the cell apoptosis due to AATBC down regulation.


Knockdown of a novel lincRNA AATBC suppresses proliferation and induces apoptosis in bladder cancer.

Zhao F, Lin T, He W, Han J, Zhu D, Hu K, Li W, Zheng Z, Huang J, Xie W - Oncotarget (2015)

Effect of AATBC knockdown on bladder cancer apoptosisA. 48 hours after transfection, apoptosis rate in UM-UC-3 cells was analyzed by flow cytometry. In cisplatin-induced groups, cisplatin was added 24 hours before examination. Data represented as means ± SD. *P < 0.05 (vs. control). B. 48 hours after transfection, apoptotic rate in EJ cells was analyzed by flow cytometry. In cisplatin-induced groups, cisplatin was added 24 hours before examination. Data represented as means ± SD.*P < 0.05 (vs. control). C. Western blotting was used to detect the expression of caspase-9, caspase-3 and PARP. β-tubulin served as loading control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4359217&req=5

Figure 5: Effect of AATBC knockdown on bladder cancer apoptosisA. 48 hours after transfection, apoptosis rate in UM-UC-3 cells was analyzed by flow cytometry. In cisplatin-induced groups, cisplatin was added 24 hours before examination. Data represented as means ± SD. *P < 0.05 (vs. control). B. 48 hours after transfection, apoptotic rate in EJ cells was analyzed by flow cytometry. In cisplatin-induced groups, cisplatin was added 24 hours before examination. Data represented as means ± SD.*P < 0.05 (vs. control). C. Western blotting was used to detect the expression of caspase-9, caspase-3 and PARP. β-tubulin served as loading control.
Mentions: We then investigated the involvement of AATBC in cell death of bladder cancer cells through inhibiting AATBC expression with siRNAs. As shown by flow cytometry analysis in Fig. 5A-B, siRNAs treatment led to the increased apoptotic rates in UM-UC-3 and EJ cells compared with that in negative control groups. After cells were induced with cisplatin, the pro-apoptotic effect of AATBC inhibition was augmented significantly when compared to that of no cisplatin-induced groups. Western blotting was used to investigate the alteration of apoptosis-related proteins induced by AATBC down-regulation. To our knowledge, the cleavages of caspase-9 and caspase-3 are prominent markers of the intrinsic apoptosis. In this present study, the occurrence and intensity of apoptosis resulted from AATBC knockdown were evidenced by the enhanced cleavages of poly (ADP-ribose) polymerase (PARP), caspase-9 and caspase-3 in both UM-UC-3 and EJ cell lines (Fig. 5C), indicating that the activation of intrinsic apoptotic pathway was involved in the cell apoptosis due to AATBC down regulation.

Bottom Line: We also found that inhibition of AATBC resulted in cell proliferation arrest through G1 cell cycle mediated by cyclin D1, CDK4, p18 and phosphorylated Rb.Furthermore, JNK inhibitor SP600125 could attenuate the apoptotic effect achieved by AATBC knockdown, confirming the involvement of JNK signaling in the induced apoptosis.Moreover, mouse xenograft model revealed that knockdown of AATBC led to suppress tumorigenesis in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.

ABSTRACT
Long intergenic noncoding RNAs (lincRNAs) play important roles in regulating various biological processes in cancer, including proliferation and apoptosis. However, the roles of lincRNAs in bladder cancer remain elusive. In this study, we identified a novel lincRNA, which we termed AATBC. We found that AATBC was overexpressed in bladder cancer patient tissues and positively correlated with tumor grade and pT stage. We also found that inhibition of AATBC resulted in cell proliferation arrest through G1 cell cycle mediated by cyclin D1, CDK4, p18 and phosphorylated Rb. In addition, inhibition of AATBC induced cell apoptosis through the intrinsic apoptosis signaling pathway, as evidenced by the activation of caspase-9 and caspase-3. The investigation for the signaling pathway revealed that the apoptosis following AATBC knockdown was mediated by activation of phosphorylated JNK and suppression of NRF2. Furthermore, JNK inhibitor SP600125 could attenuate the apoptotic effect achieved by AATBC knockdown, confirming the involvement of JNK signaling in the induced apoptosis. Moreover, mouse xenograft model revealed that knockdown of AATBC led to suppress tumorigenesis in vivo. Taken together, our study indicated that AATBC might play a critical role in pro-proliferation and anti-apoptosis in bladder cancer by regulating cell cycle, intrinsic apoptosis signaling, JNK signaling and NRF2. AATBC could be a potential therapeutic target and molecular biomarker for bladder cancer.

Show MeSH
Related in: MedlinePlus