Anticancer activity of sugiol against ovarian cancer cell line SKOV3 involves mitochondrial apoptosis, cell cycle arrest and blocking of the RAF/MEK/ERK signalling pathway
Authors: Yue Qi
Wei-Hong Qi
Liang-Yan Shi
Yan Wang
Jing Yang
Journal: Archives of Medical Science (2020)
Discipline: CLINICAL MEDICINE
Keywords: RAF/MEK/ERK; apoptosis; cell cycle arrest; cell migration; ovarian cancer.
Affiliations: Department of Gynaecology, Hubei Maternity and Child Health Hospital, Wuhan, China., Department of Obstetrics and Gynaecology, Beijing Hospital, Beijing, China., Department of Obstetrics and Gynaecology, Haidian Woman's and Children's Hospital, Beijing, China., Department of Obstetrics and Gynaecology, Dongguan Hospital of Traditional Chinese Medicine, Dongguan Guangdong, China.

Abstract:  Introduction: Ovarian cancer is one of the leading causes of cancer-related deaths in women. Treatments for ovarian cancer include surgery followed by chemotherapy. However, the survival rate for ovarian cancer is still not satisfactory. Moreover, the current chemotherapy has numerous associated side effects. Therefore there is an urgent need to look for novel and more viable treatment options. Against this backdrop the present study was designed to evaluate the anticancer activity of sugiol against ovarian cancer cells. Material and methods: Cell viability was assessed by CCK8 assay, apoptosis by DAPI, AO/ER and annexin V/PI staining. Mitochondrial membrane potential and cell cycle analysis was performed by flow cytometry. Cell migration was investigated by wound healing assay. Protein expression was monitored by western blotting. Results: The results of the present study indicated that sugiol exerts significant (p &lt; 0.0001) anticancer effects on SKOV3 cancer cells with an IC50 of 25 μM. However, sugiol exhibited less cytotoxicity against normal ovarian cells with an IC50 of 62.5 μM. The anticancer effects of sugiol were found to be due to G0/G1 cell cycle arrest and mitochondrial apoptosis. Sugiol also inhibited cell migration of SKOV3 cells dose dependently. Moreover, the results showed that sugiol could inhibit the RAF/MEK/ERK signalling pathway in a dose-dependent manner. Conclusions: The results of the present study indicate that sugiol exerts potent anticancer effects on SKOV3 cells via induction of cell cycle arrest, mitochondrial apoptosis and inhibition of the RAF/MEK/ERK signalling pathway. 

Retracted: No

PubPeer comments:
 Figure 4  Estimation of apoptotic cell populations by annexin V PI staining followed by flow cytometry. ![file] For comparison: *[Left]* Figure 4 from [Luo et al (2019)] .  Annexin V PI staining showing the percentage of apoptotic MDA-T32 cells at each phase of cell cycle. The figure depicts that ferruginol increased the percentage of the apoptotic cells in a concentration dependent manner . *[right]* Figure 5 from [Yang et al (2018)] .  Estimation of apoptotic A375 populations at indicated doses by annexin V PI using flow cytometric analysis. The images are representatives of three biological experiments. The Figure indicates that the fraction of apoptotic cells (both early and late apoptosis) increased considerably with the increasing concentrations of KAM. ![] , 
 *[left]* Figure 7 from [Wang et al (2020)] .  Effect of indicated doses of sugiol on expression of p-MEK and p-ERK by western blotting. *[right]* Figure 6 from [Hua et al (2018)] .  Effect of daidzein on the RAF MEK ERK signaling pathway. Effects of the indicated doses of daidzein on the expression of RAF MEK ERK signaling pathway proteins are shown . ![file] Different conditions, different loading controls, different authors. Same substantive bands. UPDATE: Another sighting! Figure 7 from [Ning et al (2019)] .  Effect of pinoresinol on the Ras MEK ERK signalling pathway as measured by western blotting analysis. The Figure depicts that pinoresinol blocks the Ras MEK ERK signalling pahway in ovarian cancer cells concentration-dependently. ![file] The earliest sighting so far is Fig 7B from [Li et al (2018)] .  Western blot analysis of the proteins expressed following treatment of cells with 3-tetrazolyl methyl-3-hydroxy-oxindole hybrid (THOH)... (B) MEK ERK signaling pathway proteins, detected by Western blot . ![file] , 
 *[left]* Figure 6C from [Wang et al (2020)] .  expression of MMP-9 and MMP-2 . *[right]* Figure 8 from [Zhou et al (2019)] .  Effect of taxifolin on the expression of matrix metalloproteinases (MMP)-2 and 9 as depicted by western blotting. The Figure shows that taxifolin inhibits the expression of MMP-2 and MMP-9 in a concentration-dependent manner . ![file] Fig 7A from [Li et al (2018)] .  Platelet-derived growth factor D (PDGF-D) signaling pathway proteins, detected by Western blot. ![file] , 
 Archives of Medical Science published our article online first time in 2017 and the study was carried out even before that. Nonetheless, the article was assigned to the volume in 2020. *AMS takes lot of time to assign articles to an issue.* ![file] , 
 #4 Thank you Dr. Qi for responding here. Looking at the submission dates of 2 of the other papers, they were both submitted to the journals before the acceptance of your manuscript (Sept 09, 2017), meaning there could have been a leak of your data to other parties. Have you outsourced some of your experiments to external service? Have you contracted with a manuscript editing company? Did anyone out of your own group submit the manuscript for you? Those are some of my suggestions that you may need to take a look how your data were shared with others without your permission. , 
 *[left]* Fig 2.  Sugiol induces apoptosis in SKOV3 cells as depicted by DAPI staining . *[right]* Figure 4 from [Zhang et al (2019)] .  AO EB staining images showing induction of apoptosis in a dose-dependent manner by Trifolirhizin on the SNU-5 cells . ![file] UPDATE: Another sighting! Figure 5 from [Li et al (2019)] .  Effect of Sorghumol on the induction of apoptosis as indicated by the AO EB staining. ![file] ---------------------------------------------------------- For comparison with 2A: *[left]* Figure 4A from [Yu et al (2017)] .  Effect of indicated doses of globularifolin on apoptosis (A) DAPI staining . *[right]* Figure 3 from [Deng Li (2019)] .  Effect of linderalactone on the apoptosis of A549 cells as determined by DAPI staining . ![] ,