Oxymatrine synergistically enhances antitumor activity of oxaliplatin in colon carcinoma through PI3K/AKT/mTOR pathway
Authors: Yan Liu
Liqiang Qian
Quangen Gao
Guoliang Wu
Zheng Wang
Genhai Shen
Tingting Bi
Journal: APOPTOSIS (2016)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Colon carcinoma; Oxaliplatin; Oxymatrine; PI3K/AKT; Synergistically.
Affiliations: Department of General Surgery, Wujiang No.1 People's Hospital, Suzhou, 215200, China., Department of Geriatric Ward, Wujiang No.1 People's Hospital, Suzhou, 215200, China., Department of General Surgery, Wujiang No.1 People's Hospital, Suzhou, 215200, China. .

Abstract:  Oxymatrine (OMT), one of the main active components of extracts from the dry roots of Sophora flavescens, has been reported to possess many pharmacological properties including cancer-preventive and anti-cancer effects. The aim of the present study is to explore the efficiency of combination therapy with OMT and oxaliplatin (OXA) and identify the in vitro and in vivo cytotoxicity on colon cancer lines (HT29 and SW480) and mice model. Cells were treated with OMT and/or OXA and subjected to cell viability, colony formation, apoptosis, cell cycle, western blotting, xenograft tumorigenicity assay and immunohistochemistry. The results demonstrated that OMT and OXA inhibited the proliferation of colon cancer cells, and combination therapy of OMT and OXA resulted in a combination index &lt; 1, indicating a synergistic effect. Co-treatment with OMT and OXA caused G0/G1 phase arrest by upregulating P21, P27 and downregulating cyclin D, and induced apoptosis through decreasing the expression of p-PI3K, p-AKT, p-mTOR, p-p70S6K. In addition, pretreatment with a specific PI3K/AKT activator (IGF-1) significantly neutralized the pro-apoptotic activity of OXA + OMT, demonstrating the important role of PI3K/AKT in this process. Moreover, in nude mice model, co-treatment displayed more efficient inhibition of tumor weight and volume on SW480 xenograft mouse model than single-agent treatment with OXA or OMT. Immunohistochemistry analysis suggests the combinations greatly suppressed tumor proliferation, which consistent with our in vitro results. In conclusion, our findings highlight that the combination therapy with OMT and OXA exerted synergistic antitumor effects in colon cancer cells through PI3K/AKT/mTOR pathway and combination treatment with OMT and OXA would be a promising therapeutic strategy for colon carcinoma treatment. 

Retracted: No

PubPeer comments:
 *[left]* Fig 6d.  Combination treatment with OXA [oxaliplatin] and OMT [Oxymatrine] inhibited tumorigenicity in vivo. ... d H E staining analysis of the pathological features of the tumors from the four groups.  *[right]* Figure 7 from [Liu et al (2016)] **[retracted]**.  Oxymatrine upregulation of Bax and caspase 3, and downregulation of Bcl-2 and Ki67 in SMMC-7721 xenografts. A, Hematoxylin and eosin (H E) staining analyses of the pathological features of the tumors from the 4 groups (original magnification, 400u0004). B-E, The expression of caspase 3, Bax, Bcl-2, and Ki67 in xenograft tumors was analyzed by immunohistochemistry . ![] Ki67 panels overlap (after 90-deg rotations), despite different labels. , 
 Thank you so much for helping us to point out the mistakes. We apologize for these mistakes to the journal editors, reviewers and readers for any inconvenience Because the experiments and immunohistochemistry related to these articles were basically carried out at the same time, there was a possibility of partial overlap in the preservation of images and the selection of representative images, and it was easy to make a mistake. During the imageu2019s preparation, multiple photographs of random fields in two directions per sample were taken, and then cut to the same size in the Photoshop. We think that confusion appeared when selecting representative pictures of different part. We will check it carefully and contact the editor as soon as possible to correct these errors. We apologize for such an error that shouldnu2019t being made and thank you again for the comments. , 
 *[lower right]* Fig 2d.  Colony formation of HT29 and SW480 cells after OXA and or OMT treatment. *[upper right]* Fig 2d from [Liu et al (2016a)] .  Colony formation of Hep-G2 and SMMC-7721 cells after 5-Fu and or OMT treatment. Four pairs of circles appear to have been cut from single larger images. A 90-deg rotation is involved. ![file] , 
 *[right]* Fig. 4.  Effects of OXA and or OMT on cell cycle distribution. a, b Cell cycle analysis was performed in **SW480** cells after OXA and or OMT treatment as indicated for 48 h, and cell-cycle distribution was determined . *[left]* Fig. 4 from [Liu et al (2016)] .  Effects of 5-Fu and or OMT on cell cycle distribution. a, b Cell cycle analysis was performed in **SMMC-7721** cells after 5-Fu and or OMT treatment as indicated for 48 h, and cell cycle distribution was determined. Different cells, different treatments, but two pairs of flow-cytometry plots are the same. ![file] , 
 *[right]* Fig 5a.  Expression of cyclin D1, p21, p27, ... was analyzed by Western blotting assay. Glyceraldehydes 3-phosphate dehydrogenase (GAPDH) was used as the sample loading control . *[left]* Fig 4a from [Liu et al (2016a)] .  Expressions of survivin, Bax, Bcl-2, and p53 were analyzed by western blot assay. Survivin and Cyclin-D1 bands are surprisingly similar. Could the authors check? ![file] , 
 *[right]* Fig 6d.  Combination treatment with OXA and OMT inhibited tumorigenicity in vivo. ... d H E staining analysis of the pathological features of the tumors from the four groups *[left]* Fig 5b from [Liu et al (2016a)] .  Combination treatment with 5-Fu and lupeol inhibited tumorigenicity in vivo. ...b H E staining analyses of the pathological features of the tumors from the four groups. ![] Two pairs of H E-stain panels overlap, despite representing different carcinoma cell-lines (and treatments). All four pairs of TUNEL panels are the same apart from 90- or 270-deg rotations. Could the authors check for possible error? ,