Bergamottin exerts anticancer effects on human colon cancer cells via induction of apoptosis, G2/M cell cycle arrest and deactivation of the Ras/Raf/ERK signalling pathway
Authors: ShuTao Yang
Tao Lin
Hao Zhang
Journal: Archives of Medical Science (2019)
Discipline: CLINICAL MEDICINE
Keywords: apoptosis; bergamottin; cell cycle arrest; colon cancer; invasion.
Affiliations: Department of Colorectal Surgery, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning Province, China

Abstract:  Introduction: Accumulating evidence has shown the potential of bergamottin as an anticancer agent. The present study was undertaken to evaluate the anticancer affects of bergamottin (μM) against colon cancer cells. Material and methods: Antiproliferative effects were evaluated by WST-1 cell viability assay. Apoptotic effects were studied by DAPI and Annexin V/PI staining. Cell cycle analysis was carried out by flow cytometry. Transwell assay was used to study the effects on cell invasion. Protein expression was estimated by the western blot method. Results: The results showed that bergamottin suppresses the proliferation of all the human colon cancer cell lines. Nonetheless, the growth inhibitory effects of bergamottin on the HT-29 and RKO cells were more significant (IC50, 12.5 μM). The anticancer effects of bergamottin on the HT-29 and RKO cells were mainly due to apoptosis. Bergamottin could considerably increase the expression of Bax and reduce the expression Bcl-2. The cleavage of caspase-3, 8 and 9 was also enhanced upon bergamottin treatment of the colon cancer cells. Flow cytometric analysis showed that bergamottin also induced G2/M cell cycle arrest of the HT-29 and RKO cells. Additionally, bergamottin could also suppress the invasion of HT-29 and RKO cells. The Raf/MEK/ERK pathway is regarded as one of the essential pathways involved in the development and progression of cancers. Herein, it was observed that bergamottin could concentration dependently block this pathway in colon cancer cells. In vivo study revealed that bergamottin could also suppress the growth of tumours in xenografted mice models. Conclusions: Taken together, bergamottin suppresses the proliferation of colon cancer cells and may be utilised in the development of chemotherapy for colon cancer. 

Retracted: No

PubPeer comments:
 Figure 8.  Effect of bergamottin on invasion of HT-29 and RKO cells as depicted by transwell assay (A) . ![file] For comparison: Figures 2 A,B and 4 A,B from [Yang, Chen Wang (2019)] : ![] Figs 9, 10 from [Yu et al (2019)] : ![] , 
 *[above]* Figure 3.  DAPI staining (A) and annexin V PI staining (B) showing induction of apoptosis in the HT-29 and RKO colon cancer cells. Submitted: 5 April 2019. Accepted: 26 May 2019 *[below]* Fig. 2B from [Mao et al (2019)] .  Fucosterol induces apoptosis in A549 and SK-LU-1 cells as depicted by ... (B) Annexin V PI staining. Received 18 October 2018; Accepted 23 December 2018. ![file] , 
 *[above]* Figure 6.  Effect of bergamottin on expression of cell cycle related proteins in HT-29 and RKO colon cancer cells as depicted by western blot analysis. *[below]* Fig. 5 from [Mao et al (2019)] .  Effect of fucosterol on the expression of cell cycle associated proteins in A549 and SK-LU-1 cells as depicted by western blotting . ![file] , 
 *[above]* Figure 7.  Effect of bergamottin on the Raf MEK ERK signalling pathway at indicated concentrations as depicted by western blot analysis. *[below]* Fig. 7 from [Mao et al (2019)] .  Effect of fucosterol on Raf MEK ERK signalling pathway of A549 and SK-LU-1 cells as depicted by western blotting. ![file] , 
 #3 - *[above]* Figure 6.  Effect of bergamottin on expression of cell cycle related proteins in HT-29 and RKO colon cancer cells as depicted by western blot analysis. - *[below]* Fig. 5 from [Mao et al (2019)] .  Effect of fucosterol on the expression of cell cycle associated proteins in A549 and SK-LU-1 cells as depicted by western blotting . Both appear to have been sourced from Fig 2D of  Inhibition of cathepsin S confers sensitivity to methyl protodioscin in oral cancer cells via activation of p38 MAPK JNK signaling pathways ([Hsieh et al 2017] ). ![file] , 
 #4 - *[above]* Figure 7.  Effect of bergamottin on the Raf MEK ERK signalling pathway at indicated concentrations as depicted by western blot analysis. - *[below]* Fig. 7 from Mao et al (2019).  Effect of fucosterol on Raf MEK ERK signalling pathway of A549 and SK-LU-1 cells as depicted by western blotting. ![] Both appear to have been sourced from Fig 5C D of  Traditional Chinese Medicine CFF-1 induced cell growth inhibition, autophagy, and apoptosis via inhibiting EGFR-related pathways in prostate cancer ([Wu et al 2018] ). ![file] ,