Long noncoding RNA LINC00520 prevents the progression of cutaneous squamous cell carcinoma through the inactivation of the PI3K/Akt signaling pathway by downregulating EGFR
Authors: Xue-Ling Mei
Shan Zhong
Journal: Chinese medical journal (2019)
Discipline: CLINICAL MEDICINE
Keywords: lncRNAs; EGFR signaling; cSCC; LINC00520; PI3K/Akt pathway
Affiliations: Department of Dermatology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.

Abstract:  Background: Long noncoding RNAs (lncRNAs) play pivotal roles in various malignant tumors. Epidermal growth factor receptor (EGFR) signaling is associated with the pathogenesis of cutaneous squamous cell carcinoma (cSCC). This study aimed to explore the role of LINC00520 in the development of cSCC via EGFR and phosphoinositide 3-kinase-protein kinase B (PI3K/Akt) signaling pathways. Methods: A microarray analysis was applied to screen differentially expressed lncRNAs in cSCC samples. The A431 cSCC cell line was transfected and assigned different groups. The expression patterns of LINC00520, EGFR, and intermediates in the PI3K/Akt pathway were characterized using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis. Cell proliferation, migration, and invasion were detected using the MTT assay, scratch test, and Transwell assay, respectively. Cell-based experiments and a tumorigenicity assay were conducted to assess the effect of LINC00520 on cSCC progression. This study was ended in September 2017. Comparisons between two groups were analyzed with t-test and comparisons among multiple groups were analyzed using one-way analysis of variance. The nonparametric Wilcoxon rank sum test was used to analyze skewed data. The enumerated data were analyzed using the chi-square test or Fisher exact test. Results: Data from chip GSE66359 revealed depletion of LINC00520 in cSCC. Cells transfected with LINC00520 vector and LINC00520 vector + si-EGFR showed elevated LINC00520 level but decreased levels of the EGFR, PI3K, AKT, VEGF, MMP-2 and MMP-9 mRNAs and proteins, and inhibition of the growth, migration and adhesion of cSCC cells, while the si-LINC00520 group showed opposite trends (all P &lt; 0.05). Compared with the LINC00520 vector group, the LINC00520 vector + si-EGFR group showed decreased levels of the EGFR, PI3K, AKT, VEGF, MMP-2 and MMP-9 mRNAs and proteins, and inhibition of the growth, migration and adhesion of cSCC cells, while the LINC00520 vector + EGFR vector group showed opposite results (all P &lt; 0.05). Conclusion: Based on our results, LINC00520-targeted EGFR inhibition might result in the inactivation of the PI3K/Akt pathway, thus inhibiting cSCC development. 

Retracted: No

PubPeer comments:
 Unexpected similar found in Figure 4A: ![file] , 
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 Fig 2(B)  Western blotting analysis showing the levels of the EGFR, PI3K, AKT, VEGF, MMP-2, MMP-9 and phosphorylated AKT proteins . ![file] I am intrigued by the absence of background on these WBs, and the way the bands remain perfectly linear and retain the shape of the protein blobs as they move up the gel. Is it possible for the authors to upload the original scans of the gels? Numerous other papers have Figures which display the same qualities, hence my curiosity. I compiled a montage: ![] , 
 Fig 7C.  Representative images of hematoxylin and eosin (H E)-stained lymph node sections . Removing the color and increasing contrast makes it easier to see the repeated elements. ![file] ,