Combined treatment of XIAP-targeting shRNA and celecoxib synergistically inhibits the tumor growth of non‑small cell lung cancer cells in vitro and in vivo
Authors: Ping Ren
Kaizhong Wang
Zhihong Li
Hong Zhang
Journal: Oncology Reports (2015)
Discipline: CLINICAL MEDICINE
Keywords: XIAP; Celecoxib; lung cancer; NSCLC; shRNA
Affiliations: Department of Thoracic Surgery, The First Hospital of Jilin University, Chaoyang, Changchun, Jilin 130021, P.R. China.

Abstract:  X-linked inhibitor of apoptosis protein (XIAP) has been shown to be highly expressed in lung cancer, but not in normal lung tissue, which makes it an attractive target for lung cancer treatment. Celecoxib (CXB), a cyclooxygenase-2 inhibitor, is in wide clinical use for the treatment and prevention of non-small cell lung cancer (NSCLC). Therefore, in our study, we combined short hairpin RNA (shRNA) targeted to XIAP (XIAP-shRNA) with CXB and tested the effects of this combination on lung cancer cells to identify more effective therapeutics against lung cancer. An XIAP-shRNA plasmid was constructed and transfected into the A549 NSCLC cell line. The cells were then treated with CXB and XIAP-shRNA alone or in combination for indicated time periods, and the treatments were assessed for their effects on cell proliferation, apoptosis, migration, invasion and receptor signaling using the MTT, TUNEL, wound healing and Matrigel invasion assays and western blotting, respectively. In addition, an NSCLC xenograft model was prepared to observe tumor growth. It was found that both CXB and XIAP‑shRNA significantly inhibited cell proliferation, migration and invasion, and induced cell apoptosis in vitro, as well as suppressed tumor growth in vivo. Moreover, the combination of the agents significantly enhanced these effects compared to the single agent treatments. We also found that the combination treatment significantly suppressed constitutive phosphorylation of PI3K and AKT, which may contribute to the inhibition of tumor growth. These findings suggest that the combination of XIAP‑shRNA and CXB is a promising drug candidate for the treatment of NSCLC. 

Retracted: No

PubPeer comments:
 Fig 6,  Effect of CXB and XIAP-shRNA alone or in combination on the PI3K AKT signaling pathway in A549 cells. Phosphorylation activation pattern of PI3K and Akt were measured by western blotting 24 h after treatment with CXB and XIAP-shRNA alone or in combination in the A549 cell line. Blots were reprobed for u03b2-actin to normalize each lane for protein content . ![file] Unexpectedly similar to bands in Figs 2C and 5 of [Liu et al (2014)] . ![file] No authors in common. , 
 *[right]* Fig 7A.  Images of the tumor tissues from the different groups . *[left]* Fig 7A from [Liu et al (2014)] .  Images of tumor tissue with different plasmid treatments collected after sacrifice at day 35. ![file] Surprising similarities after a 180-deg flip. Red-boxed tumor seems to be duplicated in XIAP-shRNA and Control rows. , 
 *[right]* Fig 4D.  Expression of MMP-2 and MMP-9 in A549 cells was determined by western blotting. *[left]* Fig 1C from [Li et al (2014)] . ![file] , 
 Dear Hoya Camphorifolia; Thank you for your comments, we will investigate this matter and get back to you. Best regards , 
 #1 Fig 6 again, with additional bands marked. ![file] The bands overlap considerably (with a 180-deg flip in one case) with those of Figs 3C, 5 from [Meng et al (2014)] .  Western blot analysis of Bcl-2 and XIAP protein expression after infection with Ad sh-Scramble or Ad sh-NOB1. GAPDH was used as an internal control ;  Phosphorylation activation pattern of p38 MAPK, ERK1 2 and JNK was measured by western blotting 24 h after infection with Ad sh-Scramble or Ad sh-NOB1 in the TPC1 cell line . ![file] , 
 #2 Updated. *[right]* Fig 7A.  Images of the tumor tissues from the different groups . *[left]* Fig 7A from [Liu et al (2015)] .  Images of tumor tissue with different plasmid treatments collected after sacrifice at day 35. ![file] Surprising similarities after a 180-deg flip. Also, *[left]* Fig 5A from [Li et al (2015)] .  Images of tumor tissue with different group collected after sacrifice at day 21 . *[right]* Fig 7 from [Wu et al (2015)] .  miR-128 inhibits tumor growth tumorigenicity in vivo by inhibiting IRSI. (A) Images of tumors derived for different groups . ![file] ,