Skullcapflavone I suppresses proliferation of human lung cancer cells via down-regulating microRNA-21
Authors: Tao Feng
Ben Niu
Xiaofeng Qin
Yadong Yang
Jian Zhang
Ran An
Youling Bo
Journal: Experimental and Molecular Pathology (2019)
Discipline: CLINICAL MEDICINE
Keywords: Lung cancer; MicroRNA-21; PI3K/AKT/mTOR signaling pathway; Protein phosphatase 2A; Skullcapflavone I.
Affiliations: Emergency Department, Shengli Oilfield Central Hospital, Dongying 257000, China., Department of Respiratory Medicine, Shengli Oilfield Central Hospital, Dongying 257000, China., Department of Respiratory Medicine, Shengli Oilfield Central Hospital, Dongying 257000, China. Electronic address: .

Abstract:  Background: Lung cancer is the most leading cause of cancer-related deaths worldwide. Skullcapflavone I is a flavone compound extracted from Scutellaria baicalensis Georgi (Wogon). The present study investigated the effects of skullcapflavone I on human lung cancer cell proliferation, as well as underlying possible mechanism. Methods: Cell proliferation was detected using Trypan blue assay. Cell viability was measured using cell counting kit 8 (CCK-8) assay. Quantitative reverse transcription PCR (qRT-PCR) was performed to assess microRNA-21 (miR-21) expression. Cell transfection was conducted to enhance the levels of miR-21 and protein phosphatase 2A (PP2A). Western blotting was used to evaluate the expressions of proliferation cell nuclear antigen (PCNA), Cyclin D1, PP2A, phosphatidylinositol 3-kinase (PI3K), protein kinase 3 (AKT), mechanistic target of rapamycin (mTOR) and p70S6K. Results: Skullcapflavone I significantly suppressed the viability and proliferation of A549 and H1975 cells. The expressions of miR-21 in A549 and H1975 cells were drastically decreased after skullcapflavone I treatment. Overexpression of miR-21 remarkably reversed the skullcapflavone I-induced A549 cell viability inhibition. Moreover, skullcapflavone I enhanced the expression of PP2A in A549 cells. Skullcapflavone I inactivated PI3K/AKT/mTOR signaling pathway in A549 cells via up-regulating PP2A. Besides, skullcapflavone I treatment had no significant influence on human normal bronchial epithelial 16HBE cell viability, proliferation and apoptosis. Conclusion: Skullcapflavone I exerted anti-cancer effect on lung cancer cells by down-regulating miR-21 expression, up-regulating PP2A expression and then inactivating PI3K/AKT/mTOR signaling pathway. 

Retracted: Yes

PubPeer comments:
 This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels. Despite these similarities, these papers are authored by researchers from different departments and institutes, with almost no overlap in authors. The list of these papers is available here: https: docs.google.com spreadsheets d 1KXqTAyl4j-jVorFPMD2XRpr76LcIKJ0CVyIvRj0exYQ edit?usp=sharing A more detailed description of this set of papers, suspected to all be generated by a common source, a paper mill , can be found here: * https: forbetterscience.com 2020 01 24 the-full-service-paper-mill-and-its-chinese-customers (January 2020) * https: scienceintegritydigest.com 2020 02 21 the-tadpole-paper-mill (February 2020) The same paper mill has been described in these papers: * Jana Christopher - Systematic fabrication of scientific images revealed - FEBS Letters (2018) - https: febs.onlinelibrary.wiley.com doi full 10.1002 1873-3468.13201 * Jennifer A Byrne and Jana Christopher - Digital magic, or the dark arts of the 21st centuryu2014how can journals and peer reviewers detect manuscripts and publications from paper mills? - FEBS Letters (2020) - https: febs.onlinelibrary.wiley.com doi full 10.1002 1873-3468.13747 , 
 Retracted [23 May 2022] . ----------------------- This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article u201cu2026 the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy pasted from other sources, or computer generatedu201d, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article. ,