Effects of Glut1 gene silencing on proliferation, differentiation, and apoptosis of colorectal cancer cells by targeting the TGF‐β/PI3K‐AKT‐mTOR signaling pathway
Authors: Lei Han
Dong-Dong Yang
Xue-Liang Wu
Li-Kun Wang
Yong-Jiang Yang
Jun Xue
Ming Qu
Fei Guo
Journal: Journal of Cellular Biochemistry (2018)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Glut1 gene silencing; TGF-β/PI3K-AKT-mTOR signaling pathway; apoptosis; colorectal cancer; proliferation.
Affiliations: Department of General SurgeryThe First Affiliated Hospital of Hebei North UniversityZhangjiakouHebeiChina, Department of UltrasoundThe First Affiliated Hospital of Hebei North UniversityZhangjiakouHebeiChina

Abstract:  This study aims to investigate the effects of glucose transport l (Glut1) gene on proliferation, differentiation, and apoptosis of colorectal cancer (CRC) cells by regulating the TGF-β/PI3K-AKT-mTOR signaling pathway. Immunohistochemistry was conducted to detect the positive Glut1 expression. Normal human CRC epithelial cells (CCD-18Co) and CRC cell line HCT116 were grouped into the control, blank, negative control (NC), and shGlut1-1 groups. RT-qPCR and Western blotting were performed to detect the expressions of Glut1, TGF-β1, PI3K, AKT, PTEN, mTOR, Bcl-2, and Bax. Protein expression of phosphorylated-PI3K (p-PI3K), p-S473-AKT, p-S389-S6K1, p-T70-4EBP1, Cleaved caspase-3 and Cleaved-PARP were detected. MTT assay, flow cytometry, and colony formation assay were performed in order to detect cell viability, cell cycle, and apoptosis, respectively. The positive expression rate of Glut1 in CRC tissues was 75% ± 8%, while in the adjacent normal tissues it was 0%. In comparison to adjacent normal tissues, CRC tissues had increased Glut1, TGF-β1, PI3K, AKT, mTOR, and Bcl-2 expressions, and p-PI3K, p-S473-AKT, p-S389-S6K1, and p-T70-4EBP1 expressions; and decreased PTEN, Bax, Cleaved caspase-3, and Cleaved-PARP expressions. In comparison with the blank and NC groups, cells in the shGlut1-1 group showed decreased Glut1, TGF-β1, PI3K, AKT, mTOR, and Bcl-2 expressions, and p-PI3K, p-S473-AKT, p-S389-S6K1, and p-T70-4EBP1 expressions; and increased PTEN, Bax, Cleaved caspase-3, and Cleaved-PARP expressions, along with more arrested cells in C0/C1 phase than in S phase and slower cell growth. These results suggested that silencing the Glut1 gene inhibited proliferation and promoted apoptosis of CRC cells by inactivating TGF-β/PI3K-AKT-mTOR signaling pathway. 

Retracted: Yes

PubPeer comments:
 Fig 7A.  Comparison of cell apoptosis in the control, blank, NC, and shGlut1-1 groups. A, cell apoptosis detected by flow cytometry . ![file] Colored boxes indicate corresponding panels in Fig 7C of [Cai et al (2017)] . ![] Fig 11A from [Zhang et al (2018)] ![] , 
 Figs 3B, 4B. ![file] The protein blobs seem to come from the same restricted gamut shown in this montage: ![] , 
 Fig 8A.  The results of colony formation assay the control, blank, NC, and shGlut1-1 groups. A, colony formation of cells in each group . ![file] Fig 5A from [Zhou et al (2018)] .  The cloning capability of HepG2 cells. Note: A, images of clone formation of HepG2 cells . ![file] The similarity is not total, with the shGlut1-1 and 500-u03bcM erinacine panels differing near the centres of the plates. , 
 Retracted [19 July 2021] . ---------------------------------------------- The above article, published online on 08 September 2017 in Wiley Online Library has been retracted by agreement between the journal s Editor in Chief, Prof. Dr. Christian Behl, and Wiley Periodicals LLC. The retraction has been agreed following an investigation based on allegations raised by a third party. A detailed investigation revealed that several image elements of the experimental data were published elsewhere in a different scientific context. Thus, the editors consider the conclusions of this article to be invalid. ,