scholarly journals HMGB1 Promotes Resistance to Doxorubicin in Human Hepatocellular Carcinoma Cells by Inducing Autophagy via the AMPK/mTOR Signaling Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Junhua Li ◽  
Wei Zhou ◽  
Qiang Mao ◽  
Dandan Gao ◽  
Lin Xiong ◽  
...  

Chemoresistance remains as a major hindrance in the treatment of hepatocellular carcinoma (HCC). High mobility group box protein 1 (HMGB1) enhances autophagic flux and protects tumor cells from apoptosis, which results in acquired drug resistance. However, the exact mechanisms underlying HMGB1-modulated autophagy in HCC chemoresistance remain to be defined. In the present study, we found that administration of doxorubicin (DOX) significantly promoted HMGB1 expression and induced HMGB1 cytoplasmic translocation in human HCC cell lines BEL7402 and SMMC7721, which enhanced autophagy that contributes to protecting HCC cells from apoptosis and increasing drug resistance. Moreover, we observed HMGB1 translocation and elevation of autophagy in DOX-resistant BEL7402 and SMMC7721 cells. Additionally, inhibition of HMGB1 and autophagy increased the sensitivities of BEL-7402 and SMMC-7721 cells to DOX and re-sensitized their DOX-resistant cells. Subsequently, we confirmed with HMGB1 regulated autophagy by activating the 5ʹ adenosine monophosphate-activated protein kinase (AMPK)/mTOR pathway. In summary, our results indicate that HMGB1 promotes acquired DOX resistance in DOX-treated BEL7402 and SMMC7721 cells by enhancing autophagy through the AMPK/mTOR signaling pathway. These findings provide the proof-of-concept that HMGB1 inhibitors might be an important targeted treatment strategy for HCC.

2021 ◽  
Vol 17 (1) ◽  
pp. 18-36
Author(s):  
Yin-Ci Zhang ◽  
Cheng-Guang Wu ◽  
A-Min Li ◽  
Yong Liang ◽  
Dong Ma ◽  
...  

Multidrug resistance (MDR) is a key to the ineffectiveness of hepatocellular carcinoma (HCC) chemotherapy. Oxaliplatin (OXA), as one of the first-line chemotherapeutic drugs for HCC, abnormally activates the PI3K/AKT/mTOR signaling pathway and DNA damage repair pathway (NHEJ and HR), causing drug resistance and consequnet compromised efficacy. Herein, we developed a hollow polydopamine nanoparticle (H-PDA)-based nano-delivery system (O/P-HP) that contained OXA and a dual PI3K/mTOR inhibitor PKI-587 with complementary effects for combating drug resistance in cancer chemotherapy. The hollow structure of H-PDA endowed O/P-HP with high loading efficiencies of OXA and PKI-587–up to 49.6% and 7.0%, respectively. In addition, benefiting from the intracellular delivery of H-PDA as well as the highly concentrated drugs therein, O/P-HP inhibited the proliferation of OXA-resistant HR cells, resulting in a cell viability of only 17.63%. These values were significantly superior to those with OXA single-agent treatment and treatment with free OXA in combination with PKI-587. We examined the intrinsic mechanisms of the combination therapy: O/PHP had excellent anti-cancer effects via the simultaneous upstream and downstream action to re-sensitize HR cells to chemotherapy; OXA induced strong apoptosis via the direct platinum lesions on DNA molecules, while PKI-587 normalized the abnormally activated PI3K/AKT/mTOR signaling pathway and DNA damage repair pathway (NHEJ and HR) that could attenuate the effectiveness of OXA, thus resulting in inhibition of cell proliferation, migration and DNA repair enzyme activity and the augment of apoptotic effects. Such combination therapy, with simultaneous upstream and downstream action, may be a strategy for minimizing resistance for anti-cancer treatments.


Oncotarget ◽  
2015 ◽  
Vol 6 (40) ◽  
pp. 42813-42824 ◽  
Author(s):  
Jie Ji ◽  
Junwei Tang ◽  
Lei Deng ◽  
Yu Xie ◽  
Runqiu Jiang ◽  
...  

2015 ◽  
Vol 309 (3) ◽  
pp. E302-E310 ◽  
Author(s):  
Caixia Li ◽  
Helmy M. Siragy

High glucose reduces autophagy and enhances apoptosis of podocytes. Previously, we reported that high glucose induced podocyte injury through upregulation of the (pro)renin receptor (PRR). We hypothesized that increasing PRR reduces autophagy and increases apoptosis of mouse podocytes exposed to high glucose via activation of the PI3K/Akt/mTOR signaling pathway. Mouse podocytes were cultured in normal (5 mmol/l) or high (25 mmol/l) d-glucose for 48 h. High glucose significantly increased mRNA and protein levels of PRR, phosphorylation of PI3K/Akt/mTOR, and p62. In contrast, high glucose decreased activation of UNC-51-like kinase-1 (ULK1) by phosphorylating Ser757 and protein levels of microtubule-associated protein-1 light chain 3B (LC3B)-II and Lamp-2. Bafilomycin A1 increased LC3BII and p62 accumulation in high-glucose-treated cells. High glucose reduced the autophagic flux. Confocal microscopy studies showed significant reduction in the protein level of LC3B in response to high glucose. Cyto-ID autophagy staining showed a significant decrease in autophagosome formation with high glucose. In the absence of PRR, activation of Akt with sc-79 or mTOR with MHY-1485 increased p62 accumulation. Caspase-3/7 activity and apoptosis monitored by TUNEL assay were significantly increased in podocytes treated with high glucose. PRR siRNA significantly reversed the effects of high glucose. Based on these data, we conclude that high glucose decreases autophagy and increases apoptosis in mouse podocytes through the PRR/PI3K/Akt/mTOR signaling pathway.


2012 ◽  
Vol 103 (11) ◽  
pp. 1929-1937 ◽  
Author(s):  
Sang-Won Hong ◽  
Kyung Hee Jung ◽  
Hee-Seung Lee ◽  
Myung-Joo Choi ◽  
Mi Kwon Son ◽  
...  

Author(s):  
Dongmei Zhan ◽  
Tengyang Ni ◽  
Haibo Wang ◽  
Mengying Lv ◽  
Masataka Sunagawa ◽  
...  

Background: This study aimed to determine the effect and mechanism of Celastrol inhibiting the proliferation and decreases drug resistance of cisplatin-resistant gastric cancer cells. Objective: To explore the effect and mechanism of Celastrol on proliferation and drug resistance of human gastric cancer cisplatin-resistant cells SGC7901/DDP. Methods: The thiazole blue (MTT) method was used to detect the sensitivity of human gastric cancer cisplatin-resistant cells SGC7901/DPP to cisplatin and Celastrol to determine the Drug resistance index (DRI). According to the half inhibitory concentration (IC50) value, the action concentration of the following experimental drugs was set to reduce the cytotoxicity; Annexin V-FITC/PI double staining method was used to detect the apoptosis of SGC7901/DDP cells induced by Celastrol; Western Blot was used to examine the expression levels of P-glycoprotein (P-gp), Multidrug Resistance Associated Protein 1 (MRP1), Breast Cancer Resistance Associated Protein (Breast Cancer Resistance)-relative protein (BCRP), and mechanistic Target of Rapamycin (mTOR) pathway related proteins; Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the mRNA expression levels of P-gp, MRP1, and BCRP. Results: (1) Compared with the control group (We set the untreated group as the control group), the proliferation of the SGC7901/DPP cells was significantly inhibited after treating with 0.1-6.4μmol/L Celastrol in a time- and concentration-dependent manner (P<0.05). The Drug resistance index DRI of the SGC7901/DPP cells to DDP was 5.64. (2) Compared with the control group, Celastrol could significantly inhibit the proliferation and induce the apoptosis of the SGC7901/DPP cells (P<0.05). (3) The mRNA and protein expression levels of P-gp, MRP1, and BCRP in the SGC7901/DPP cells were significantly higher than those in the SGC7901 cells. However, after treating with Celastrol, the expression levels of P-gp, MRP1, and BCRP in the SGC7901/DPP cells were significantly reduced (P<0.05). (4) Compared with the control group, the Celastrol treatment also reduced the expression of the mTOR signaling pathway related proteins, suggesting that the mTOR signaling pathway may be involved in the process of Celastrol inhibiting the proliferation of the SGC7901/DDP cells and reducing their drug resistance. (5) Significantly, the combination of Celastrol and DDP reduced the expression of P-gp, MRP1, and BCRP in the SGC7901/DPP cells. Conclusion: Celastrol can inhibit the proliferation of the SGC7901/DDP cells, induce their apoptosis, and reduce the expression of drug resistance genes, probably by inhibiting the expression of the proteins related to the mTOR signaling pathway.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yuli Hou ◽  
Shanshan Wang ◽  
Mengdan Gao ◽  
Jing Chang ◽  
Jianping Sun ◽  
...  

Purpose. Interferon-induced transmembrane protein 3 (IFITM3) is a key signaling molecule regulating cell growth in some tumors, but its function and mechanism in hepatocellular carcinoma (HCC) remain unknown. Our study investigated the relationship between the expression of IFITM3 and HCC development. Material and Methods. IFITM3 expression was identified via multiple gene expression databases and investigated in HCC tissue samples. Then, PLC/PRF/5 cells were transfected with lentivirus to knock down and overexpress the expression of IFITM3. IFITM3 expression, cell proliferation, and migration were detected by qRT-PCR, western blotting, QuantiGene Plex 2.0 assay, immunohistochemistry, CCK-8, and wound healing tests. RNA-seq technology identified the PI3K/AKT/mTOR pathway as an IFITM3-related signaling pathway for investigation. Results. IFITM3 expression was higher in HCC tissues than in adjacent normal tissues, and the level of IFITM3 was higher in HCC tissues with low differentiation and metastatic potential than in those with high/medium differentiation and without metastatic potential. A higher RNA level of IFITM3 was found in samples with IFITM3 rs12252-CC genotype rather than the TT genotype. Knockdown of IFITM3 in PLC/PRF/5 cells inhibited cell proliferation and migration, blocked the expression of the PI3K/AKT/mTOR signaling pathway, and decreased the expression of vimentin. The results were opposite with the overexpression of IFITM3. Conclusion. Upregulation of IFITM3 plays a role in the development of HCC. Possibly through regulating HCC cell proliferation and migration, these effects are associated with the PI3K/AKT/mTOR signaling pathway. Upregulation of IFITM3 is also associated with the IFITM3 rs12252-CC genotype.


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