Icaritin induces mitochondrial apoptosis by up-regulating miR-124 in human oral squamous cell carcinoma cells
Authors: Xingdan Li
Yanjin Liu
Yaqiong Jie
Xinguang Han
Jinhong Miao
Qianyun Niu
Limin Jin
Journal: Biomedicine & Pharmacotherapy (2017)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Apoptosis; DNMT1; Icaritin; MiR-124; Sp1.
Affiliations: Department of Oral & Maxillofacial Surgery, The First Affiliated Hospital, Zhengzhou University, China., Department of Nursing Management,The First Affiliated Hospital, Zhengzhou University, China., Department of Oral & Maxillofacial Surgery, Stomatological Hospital of Nanyang, China., Department of Oral & Maxillofacial Surgery, The First Affiliated Hospital, Zhengzhou University, China. Electronic address: .

Abstract:  Aim of the study: The present study is aimed to investigate the apoptosis-inducing effect of icaritin in human oral squamous cell carcinoma (OSCC) cells and the associated mechanisms. Materials and methods: KB and SCC9 cell lines were used as model cell lines. Effect of icaritin on apoptosis was analyzed by flow cytometry. The effect of icaritin on mitochondrial apoptotic pathway was demonstrated by loss of mitochondrial membrane potential and release of cytocrome C from mitochondria. MiR-124 mimic and miR-124 inhibitor were used to manipulate the expression of miR-124 in OSCC cells. SiRNA targeting Sp1 and DNMT1 as well as Sp1 and DNMT1 overexpressing vector were utilized to confirm their roles in the apoptosis-inducing effect of icaritin in OSCC cells. Activation of relevant signaling pathway by icaritin and effect of icaritin on expression of targeting molecules were determined by western blots or qRT-PCR. Results: Our results showed that icaritin inhibited tumor cell viability in a dose- and time-dependent manner, and induced cell apoptosis via intrinsic mitochondrial pathway by upregulating miR-124. Moreover, our results showed that the icaritin exerted regulatory effect on miR-124 through suppressing Sp1/DNMT1 signaling. Conclusion: Our data provide the first experimental evidence that icaritin induces mitochondrial apoptosis in OSCC cells by upregulating miR-124 and suggest a new mechanism to explain its anti-tumor effects. 

Retracted: No

PubPeer comments:
 Figure 2. Panels in Figure 2A (different concentrations of Icaritin added to 2 different cell types) look very similar to panels in Figure 2C (Icaritin + vehicle added). In Figure 2C a Caspase inhibitor molecule, z-VAD-FMK was added to the cells, so I assume that the panels labeled  vehicle had the carrier solution without the z-VAD-FMK added to the cells. It appears it is therefore a different experiment than the one in Figure 2A. There is no information in the Methods on the Caspase inhibitor concentration, manufacturer or vehicle. Could the authors please provide some more background for the experiment performed in Figure 2C?  , 
 In Figure 5F, both  Sp1 shRNA flow cytometry panels (marked here with an orange box) look very different than the other panels. The panel resolution, number of dots, and position of the gates are all very different than the other panels. Yet, all panels are compared to each other. Could the authors please provide a justification how panels with a different cutoff (gate position) can be compared?  , 
 Fig 1B.  Icaritin suppresses OSCC cell growth in dose- and time-dependent manner. .... B. Icaritin inhibits cell proliferation .  The same plates appear in other papers by otherwise-unrelated authors, suggesting a papermill provenance for the FIgure. Here, Fig 2(b) from [Xie et al (2019)] :  More appearances in that thread:  For more details I refer readers to a Google spreadsheet: https: docs.google.com spreadsheets d 13K6zoo2oSATsFlY7YGyvm2_Xs1jibs0RH4nKQP5y8DY edit#gid=0 and a blogpost. https: forbetterscience.com 2020 02 27 dark-satanic-papermills UPDATE: Earlier sightings! Fig 1B from [Li et al (2019)] .  AIF induces apoptosis in CRC cells. ... B. Colony formation assay of HCT-116 and SW480 cells treated with AIF (5 and 10 u00b5M) for the indicated durations. 2B from [Han et al (2017)] .  MiR-429 promotes cell proliferation. ... B. MiR-429 promotes long term cell proliferation, as determined by colony formation.  ,