Human leptin protein activates the growth of HepG2 cells by inhibiting PERK‑mediated ER stress and apoptosis

Xiong,Ying; Zhang,Jie; Liu,Man; An,Mingwei; Lei,Ling; Guo,Wuhua

doi:10.3892/mmr.2014.2373

Human leptin protein activates the growth of HepG2 cells by inhibiting PERK‑mediated ER stress and apoptosis

Authors:
- Ying Xiong
- Jie Zhang
- Man Liu
- Mingwei An
- Ling Lei
- Wuhua Guo
View Affiliations

Affiliations: Department of Gastroenterology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China, Department of Plastic and Cosmetic Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China, Department of Anorectal, The Affiliated Hospital of Jiangxi Traditional Chinese Medicine University, Nanchang, Jiangxi 330006, P.R. China
Published online on: July 14, 2014 https://doi.org/10.3892/mmr.2014.2373
Pages: 1649-1655

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )

Metrics: Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )

Cited By (CrossRef): 0 citations Loading Articles...

Abstract

Current treatment modalities for various types of hepatic cancer, which has an increasing incidence rate, are inadequate and novel therapies are required. Therefore, identifying targets for liver cancer is becoming increasingly valuable to develop novel methods for therapy. The aim of the present study was to examine the growth activation mechanism of the leptin protein in the liver cancer cell line HepG2. The effects of the leptin protein on cell death were investigated by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide analysis. DNA fragmentation and terminal deoxynucleotidyl transferase dUTP nick end labeling analysis were also performed to detect cell apoptosis. The expression of leptin and three endoplasmic reticulum (ER) stress unfolded protein response (UPR) proteins, including activating transcription factor 6, phosphorylated‑PKR‑like ER kinase (p‑PERK) and inositol requiring protein 1, were investigated for the examination of ER stress. The mRNA UPR proteins were also detected by reverse transcription polymerase chain reaction. The apoptosis‑associated caspase 12 and C/EBP homologous protein (CHOP) was detected by western blot analysis. The expression of or incubation with the leptin protein was able to activate cell growth and inhibit cell death and apoptosis. In cells that expressed leptin or were incubated with leptin protein (pep-LPT), cisplatin‑induced ER stress‑associated mRNA transcription and protein activation were inhibited. Levels of the ER stress UPR pathway protein, PERK, increased significantly in leptin‑silenced cells when treated with cisplatin as compared with those in the leptin‑expressing or pep-LPT cells. Furthermore, caspase 12 activation was inhibited in ex‑LPT, pep‑LPT and HepG2 cells. In conclusion, human leptin protein is involved in promoting the proliferation of HepG2 cells through inhibiting the ER stress‑associated apoptotic pathway. The PERK UPR pathway and the apoptotic factor caspase 12 were found to be involved in the inhibition of apoptosis and enhancement of proliferation.

View Figures

View References

1	Wang Y, O’Connor M, Xu Y and Liu X: Symptom clusters in Chinese patients with primary liver cancer. Oncol Nurs Forum. 39:E468–E479. 2012. View Article : Google Scholar : PubMed/NCBI
2	Li Y, Huang X, Zhang Q and Ma K: Phosphorylation of cMet tyrosine residues in murine ascetic hepatic cancer cell lines with different lymph node metastatic potentials. Mol Med Rep. 8:655–661. 2013.PubMed/NCBI
3	Yang X, Zu X, Tang J, Xiong W, Zhang Y, Liu F and Jiang Y: Zbtb7 suppresses the expression of CDK2 and E2F4 in liver cancer cells: implications for the role of Zbtb7 in cell cycle regulation. Mol Med Rep. 5:1475–1480. 2012.PubMed/NCBI
4	Xu C, Bailly-Maitre B and Reed JC: Endoplasmic reticulum stress: cell life and death decisions. J Clin Invest. 115:2656–2664. 2005. View Article : Google Scholar : PubMed/NCBI
5	Moenner M, Pluquet O, Bouchecareilh M and Chevet E: Integrated endoplasmic reticulum stress responses in cancer. Cancer Res. 67:10631–10634. 2007. View Article : Google Scholar : PubMed/NCBI
6	Zhang X, Zhang HQ, Zhu GH, Wang YH, Yu XC, Zhu XB, Liang G, Xiao J and Li XK: A novel mono-carbonyl analogue of curcumin induces apoptosis in ovarian carcinoma cells via endoplasmic reticulum stress and reactive oxygen species production. Mol Med Rep. 5:739–744. 2012.
7	Banjerdpongchai R, Punyati P, Nakrob A, Pompimon W and Kongtawelert P: 4′-Hydroxycinnamaldehyde from Alpinia galanga (Linn) induces human leukemic cell apoptosis via mitochondrial and endoplasmic reticulum stress pathways. Asian Pac J Cancer Prev. 12:593–598. 2011.
8	Choi EJ and Kim T: Equol induced apoptosis via cell cycle arrest in human breast cancer MDA-MB-453 but not MCF-7 cells. Mol Med Rep. 1:239–244. 2008.PubMed/NCBI
9	Hung JY, Hsu YL and Ni WC: Oxidative and endoplasmic reticulum stress signaling are involved in dehydrocostuslactone-mediated apoptosis in human non-small cell lung cancer cells. Lung Cancer. 68:355–365. 2010. View Article : Google Scholar : PubMed/NCBI
10	Brennan AM and Mantzoros CS: Drug insight: the role of leptin in human physiology and pathophysiology - emerging clinical applications. Nat Clin Pract Endocrinol Metab. 2:318–327. 2006. View Article : Google Scholar : PubMed/NCBI
11	Duru S, Sönmez Z, Saygideğer Y, Sever O, Onal B and Ardiç S: The relationship between stage and tumor type and serum leptin level and leptin expression on tumor tissue in lung cancer. Tuberk Toraks. 59:427–428. 2011.(In Turkish).
12	Yerlikaya A, Altikat S, Irmak R, Cavga FZ, Kocacan SA and Boyaci I: Effect of bortezomib in combination with cisplatin and 5-fluorouracil on 4T1 breast cancer cells. Mol Med Rep. 8:277–281. 2013.PubMed/NCBI
13	Dong Z, Xu X, Du L, Yang Y, Cheng H, Zhang X, Li Z, Wang L, Li J, Liu H, Qu X and Wang C: Leptin-mediated regulation of MT1-MMP localization is KIF1B dependent and enhances gastric cancer cell invasion. Carcinogenesis. 34:974–983. 2013. View Article : Google Scholar
14	Zhang GA, Hou S, Han S, Zhou J, Wang X and Cui W: Clinicopathological implications of leptin and leptin receptor expression in papillary thyroid cancer. Oncol Lett. 5:797–800. 2013.PubMed/NCBI
15	Wang X, Dong CF, Shi Q, Shi S, Wang GR, Lei YJ, Xu K, An R, Chen JM, Jiang HY, Tian C, Gao C, Zhao YJ, Han J and Dong XP: Cytosolic prion protein induces apoptosis in human neuronal cell SH-SY5Y via mitochondrial disruption pathway. BMB Rep. 42:444–449. 2009. View Article : Google Scholar : PubMed/NCBI
16	Shuda M, Kondoh N, Imazeki N, Tanaka K, Okada T, Mori K, Hada A, Arai M, Wakatsuki T, Matsubara O, Yamamoto N and Yamamoto M: Activation of the ATF6, XBP1 and grp78 genes in human hepatocellular carcinoma: a possible involvement of the ER stress pathway in hepatocinogenesis. J Hepatol. 38:605–614. 2003. View Article : Google Scholar
17	Lee do Y, Lee KS, Lee HJ, Kim do H, Noh YH, Yu K, Jung HY, Lee SH, Lee JY, Youn YC, Jeong Y, Kim DK, Lee WB and Kim SS: Activation of PERK signaling attenustes Aβ-mediated ER stress. PLoS One. 5:e104892010.
18	Lee H, Noh JY, Oh Y, Kim Y, Chang JW, Chung CW, Lee ST, Kim M, Ryu J and Jung YK: IRE1 plays an essential role in ER stress-mediated aggregation of mutant huntingtin via the inhibition of autophagy flux. Hum Mol Genet. 21:101–114. 2012. View Article : Google Scholar : PubMed/NCBI
19	Zhang S, Zhang Q, Zhang L, Li C and Jiang H: Expression of ghrelin and leptin during the development of type 2 diabetes mellitus in a rat model. Mol Med Rep. 7:223–228. 2013.PubMed/NCBI
20	Gribovskaja-Rupp I, Kosinski L and Ludwig KA: Obesity and colorectal cancer. Clin Colon Rectal Surg. 24:229–243. 2011. View Article : Google Scholar
21	Vansaun MN: Molecular pathways: adiponectin and leptin signaling in cancer. Clin Cancer Res. 19:1926–1932. 2013. View Article : Google Scholar : PubMed/NCBI
22	Lai Q and Sun Y: Human leptin protein induces proliferation of A549 cells via inhibition of PKR-Like ER kinase and activating transcription factor-6 mediated apoptosis. Yonsei Med J. 54:1407–1415. 2013. View Article : Google Scholar : PubMed/NCBI
23	Shen Y, Wang Q, Zhao Q and Zhou J: Leptin promotes the immune escape of lung cancer by inducing proinflammatory cytokines and resistance to apoptosis. Mol Med Rep. 2:295–299. 2009.PubMed/NCBI
24	Kimball SR and Jefferson LS: Induction of REDD1 gene expression in the liver in response to endoplasmic reticulum stress is mediated through a PERK, eIF2α phosphorylation, ATF4-dependent cascade. Biochem Biophys Res Commun. 427:485–489. 2012.PubMed/NCBI
25	Wang X, Shi Q, Xu K, Gao C, Chen C, Li XL, Wang GR, Tian C, Han J and Dong XP: Familial CJD associated PrP mutants within the transmembrane region induced Ctm-PrP retention in ER and trigger apoptosis by the ER stress in SH-SY5Y cells. PLoS One. 6:e146022011. View Article : Google Scholar
26	Wu CT, Weng TI, Chen LP, Chiang CK and Liu SH: Involvement of caspase-12-dependent apoptotic pathway in ionic radiocontrast urografin-induced renal tubular injury. Toxicol Appl Pharmacol. 266:167–175. 2013. View Article : Google Scholar : PubMed/NCBI
27	Yang X and Huang N: Berberine induces selective apoptosis through the AMPK-mediated mitochondrial/caspase pathway in hepatocellular carcinoma. Mol Med Rep. 8:505–510. 2013.