MicroRNA-138 suppresses proliferation, invasion and glycolysis in malignant melanoma cells by targeting HIF-1α
Authors: Bin Peng
Yao Chen
Yong Chen
Jia Chen
Jianda Zhou
G U He
K E Cao
Shaohua Wang
Bin He
Journal: Experimental and Therapeutic Medicine (2016)
Discipline: CLINICAL MEDICINE
Keywords: glycolysis; hypoxia-inducible factor-1α; invasion; melanoma; microRNA-138
Affiliations: Department of Plastic Surgery, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China; Department of Plastic Surgery, Longgang Orthopedics Hospital of Shenzhen, Shenzhen, Guangdong 518116, P.R. China., Department of Oncology, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China., Department of Plastic Surgery, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China.

Abstract:  MicroRNAs (miRs) may induce mRNA degradation or inhibit protein translation by directly binding to the 3'-untranslational region of target mRNAs. It has been reported that miR-138 is downregulated in malignant melanoma (MM) cells. However, the role of miR-138 in MM cell proliferation, invasion and energy metabolism remains unknown. These were investigated using reverse transcription-quantitative polymerase chain reaction was used to evaluate the expression of miR-138 and the mRNA expression of hypoxia-inducible factor-1α (HIF-1α), as HIF-1α serves a crucial role in glycolysis, which is important for tumor growth. In addition, western blot analysis was used to detected the protein expression of HIF-1α, while MTT and Transwell assays evaluated cell proliferation and invasion, respectively. Furthermore, glucose consumption and lactic acid production were assessed. These tests were conducted using the normal human melanocyte cell line HM and the MM cell line WM451, which was transfected variously with scramble miR mimics, miR-138 mimics, miR-138 inhibitor, non-specific small interfering (si)RNA, HIF-1α siRNA, or co-transfected with miR-138 mimics and pc-DNA3.1(+)-HIF-1α plasmid. The results showed that miR-138 was significantly downregulated in MM WM451 cells compared to a normal melanocyte cell line HM. Overexpression of miR-138 significantly inhibited the proliferation and invasion of WM451 cells. These effects were similar to those induced by the siRNA-mediated knockdown of HIF-1α, a direct target of miR-138. Further investigation found that miR-138 negatively regulated the protein expression of HIF-1α in WM451 cells. Moreover, upregulation of miR-138 notably inhibited the glycolysis level, as demonstrated by reduced glucose consumption and lactic acid production, which could be reversed by the overexpression of HIF-1α. In summary, the present study demonstrated that miR-138 is able to inhibit proliferation, invasion and glycolysis in MM cells, potentially by directly targeting HIF-1α. 

Retracted: No

PubPeer comments:
 Unexpected similarity. *[left]* Fig 2C.  Western blot was conducted to determine the protein level of HIF-1u03b1 in WM451 cells transfected with NC and HIF-1u03b1 siRNA, respectively . *[right]* Fig 4D from [Zhou et al (2016)] .  Western blot was used to examine the protein levels of EMT-related genes . ![file] , 
 #1 Adventures in Western Blot versatility: *[above]* Fig 3B,C from [Wu et al (2017)] .  Western blotting was used to measure the expression of DKK3 in U2OS cells transfected with (B) miR-NC and miR-92b mimic, as well as in U2OS cells transfected with (C) NC inhibitor and miR-92b inhibitor. *[middle]* Fig 6A from [Zhao, Wu Li (2017)] .  Western blot analysis was conducted to examine the expression of HK2 and LDH-A protein in (A) WM451 ... cells transfected with miR-33b mimic or co-transfected with miR-33b mimic and pcDNA3.1-HIF-1u03b1 plasmid . With 180-deg flipped version. *[below]* Figs 4D from [Zhou et al (2016)] ,  Western blot was used to examine the protein levels of EMT-related genes ; and **Fig 2C from [Chen et al (2016)] **,  Western blot was conducted to determine the protein level of HIF-1u03b1 in WM451 cells transfected with NC and HIF-1u03b1 siRNA, respectively *[vertically stretched]*. ![file] ,