OSI-027 alleviates oxaliplatin chemoresistance in gastric cancer cells by suppressing P-gp induction

2020 ◽  
Vol 20 ◽  
Author(s):  
En Xu ◽  
Hao Zhu ◽  
Feng Wang ◽  
Ji Miao ◽  
Shangce Du ◽  
...  

: Gastric cancer is one of the most common malignancies worldwide and the third leading cause of cancer-related death. In the present study, we investigated the potential activity of OSI-027, a potent and selective mammalian target of rapamycin complex 1/2 (mTOR1/2) dual inhibitor, alone or in combination with oxaliplatin against gastric cancer cells in vitro. Cell counting kit-8 assays and EdU staining were performed to examine the proliferation of cancer cells. Cell cycle and apoptosis were detected by flow cytometry. Western blot was used to detect the elements of the mTOR pathway and Pgp in gastric cancer cell lines. OSI-027 inhibited the proliferation of MKN-45 and AGS cells by arresting the cell cycle in the G0/G1 phase. At the molecular level, OSI-027 simultaneously blocked mTORC1 and mTORC2 activation, and resulted in the downregulation of phosphor-Akt, phpspho-p70S6k, phosphor-4EBP1, cyclin D1, and cyclin-dependent kinase4 (CDK4). Additionally, OSI-027 also downregulated P-gp, which enhanced oxaliplatin-induced apoptosis and suppressed multidrug resistance. Moreover, OSI-027 exhibited synergistic cytotoxic effects with oxaliplatin in vitro, while a P-gp siRNA knockdown significantly inhibited the synergistic effect. In summary, our results suggest that dual mTORC1/mTORC2 inhibitors (e.g., OSI-027) should be further investigated as a potential valuable treatment for gastric cancer.

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Li-Qun Ren ◽  
Qi Li ◽  
Yang Zhang

Objective. Gastric cancer, one of the most common malignant tumors worldwide, arises from the gastric mucosal epithelium and severely affects patient health and quality of life. Luteolin (LUT) is a flavonoid found in vegetables and fruits with diverse functions. A large number of studies have confirmed that LUT has an antitumor effect. Therefore, this study is aimed at verifying whether LUT can exert antitumor effects in synergy with oxaliplatin (OXA). As such, we examined the effects of LUT, OXA, and their coadministration in a gastric adenocarcinoma cell line (SGC-7901). We used the MTT assay to quantify the proliferation of SGC-7901 cells, flow cytometry to detect the cell cycle and apoptosis, ELISA to detect the expression of cell-cycle-related proteins, and western blot to detect the expression of related apoptotic factors. The results of this study show that the combination of LUT and OXA inhibited SGC-7901 cell proliferation and induced apoptosis by altering cell-cycle proportions. In addition, the combination also activated Cyt c/caspase signaling in SGC-7901 cells. In summary, LUT synergy with OXA inhibited the proliferation of gastric cancer cells in vitro. The present study also elucidated the mechanism by which LUT potentiated the sensitivity of SGC-7901 cells to OXA through the Cyt c/caspase pathway.


2022 ◽  
Vol 22 ◽  
Author(s):  
Meng Li ◽  
Jiang Chang ◽  
Honglin Ren ◽  
Defeng Song ◽  
Jian Guo ◽  
...  

Background Increased CCKBR expression density or frequency has been reported in many neoplasms. Objective We aimed to investigate whether CCKBR drives the growth of gastric cancer (GC) and its potential as a therapeutic target of immunotoxins. Methods A lentiviral interference system was used to generate CCKBR-knockdown gastric cancer cells. Cell Counting Kit-8 and clonogenic assays were used to evaluate cell proliferation. Wound-healing and cell invasion assays were performed to evaluate cell mobility. Cell cycle was analyzed by flow cytometry. Tumor growth in vivo was investigated using a heterologous tumor transplantation model in nude mice. In addition, we generated the immunotoxin FQ17P and evaluated the combining capacity and tumor cytotoxicity of FQ17P in vitro. Results Stable downregulation of CCKBR expression resulted in reduced proliferation, migration and invasion of BGC-823 and SGC-7901 cells. The impact of CCKBR on gastric cancer cells was further verified through CCKBR overexpression studies. Downregulation of CCKBR expression also inhibited the growth of gastric tumors in vivo. Furthermore, FQ17P killed CCKBR-overexpressing GC cells by specifically binding to CCKBR on the tumor cell surface. Conclusion The CCKBR protein drives the growth, migration, and invasion of gastric cancer cells, and it might be a promising target for immunotoxin therapy based on its aberrant expression, functional binding interactions with gastrin, and subsequent internalization.


2018 ◽  
Vol 818 ◽  
pp. 124-131 ◽  
Author(s):  
Hongzhi Du ◽  
Yang Liu ◽  
Xudong Chen ◽  
Xiaowen Yu ◽  
Xiaoying Hou ◽  
...  

2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 53-53
Author(s):  
Yongping Liu ◽  
Yang Ling ◽  
Qiu feng Qi ◽  
Yaodong Pan

53 Background: HER2 amplification occurs in about 20% of gastric cancers, and trastuzumab in combination with cisplatin based chemotherapy has been reported to improve oncological outcomes in gastric and gastro-oesophageal junction cancer with HER2 gene amplification. The aim of this study was to evaluate the potentially useful combined antitumor efficacy of trastuzumab and platinum agents in gastric cancer cells and to elucidate further the mechanisms possibly involved in the interaction between the trastuzumab and platinum agents. Methods: Gene expression was determined by using real-time quantitative PCR in gastric cancer cell lines. The chemosensitivity of gastric cancer cells to platinum agents and the apoptotic effect of drugs in vitro were evaluated using cellTiter 96 Aqueous One Solution Cell Proliferation Assay kit and double staining with both Annexin-V-FITC and PI, respectively. Results: Treatment with 1.0μg/ml trastuzumab for 48h could significantly increase sensitivity of oxaliplatin or cisplatin in HER2 amplified gastric cancer cells, and the IC50 of oxaliplatin and cisplatin were reduced to about 3.29 times and 6.91 times, respectively. Apoptosis analysis also indicated that trastuzumab significantly increased both oxaliplatin and cisplatin-induced apoptosis in NCI-N87 cells. Analysis of telomere-related genes revealed that trastuzumab singly and pretreatment with trastuzumab for 48h followed by oxaliplatin or cisplatin for another 48h could significantly downregulate the mRNA expression of TPP1, TRF1, TRF2, TRF2IP, POT1 and TIN2 genes. Conclusions: Our results describe the potential role of low dose trastuzumab to increase sensitivity of oxaliplatin and cisplatin in HER2 amplified gastric cancer cells, which may be partially through downregulating the expression levels of telomere-related genes.


2016 ◽  
Vol 38 (5) ◽  
pp. 1939-1951 ◽  
Author(s):  
Lei Li ◽  
Lian-Mei Zhao ◽  
Su-li Dai ◽  
Wen-Xuan Cui ◽  
Hui-Lai Lv ◽  
...  

Background/Aims: Periplocin is extracted from the traditional herbal medicine cortex periplocae, which has been reported to suppress the growth of cancer cells. However, little is known about its effect on gastric cancer cells. Methods: Gastric cancer cells were treated with periplocin, and cell viability was assessed using MTS assay. Flow cytometry and TUNEL staining were performed to evaluate apoptosis, and protein expression was examined by western blotting. Microarray analysis was used to screen for changes in related genes. Results: We found that periplocin had an inhibitory effect on gastric cancer cell viability in a dose-dependent manner. Periplocin inhibited cell viability via the ERK1/2-EGR1 pathway to induce apoptosis. Periplocin also inhibited the growth of tumor xenografts and induced apoptosis in vivo. Conclusion: Our results show that periplocin inhibits the proliferation of gastric cancer cells and induces apoptosis in vitro and in vivo, indicating its potential to be used as an antitumor drug.


2021 ◽  
Vol 10 ◽  
Author(s):  
Beibei Chen ◽  
Sai-Qi Wang ◽  
Jinxi Huang ◽  
Weifeng Xu ◽  
Huifang Lv ◽  
...  

Kremen2 (Krm2) plays an important role in embryonic development, bone formation, and tumorigenesis as a crucial regulator of classical Wnt/β-catenin signaling pathway. However, the role of Krm2 in gastric cancer is not clear. The aim of this study was to explore the regulatory role of Krm2 in the tumorigenesis and metastasis of gastric cancer. It was demonstrated that, compared to para-cancerous tissues, Krm2 was significantly up-regulated in gastric cancer tissues and was positively correlated with the pathological grade of gastric cancer patients. Given that Krm2 is abundantly expressed in most tested gastric cancer cell lines, Krm2 knockdown cell models were established and further used to construct mice xenograft model. After knocking down Krm2, both the cell survival in vitro and tumorigenesis in vivo of gastric cancer cells were inhibited. At the same time, knockdown of Krm2 induced apoptosis, cell cycle arrest at G2/M phase and repression of migration in gastric cancer cells in vitro. Mechanistically, we found that knockdown of Krm2 suppressed PI3K/Akt pathway. Therefore, we revealed the novel role and the molecular mechanism of Krm2 in promoting the tumorigenesis and metastasis in gastric cancer. Krm2 can be a potent candidate for designing of targeted therapy.


2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 14-14
Author(s):  
Shoumin Zhu ◽  
Abbes Belkhiri ◽  
Wael El-Rifai

14 Background: Dopamine and cAMP-regulated phosphoprotein, Mr 32000 (DARPP-32) is amplified and overexpressed in approximately 70% of gastric cancers. The prognosis for gastric cancer patients remains poor, especially in more advanced stages. Recently, it was suggested that CXCL-12 and its receptor, CXCR4, are involved in gastric cancer metastasis. However, the detailed mechanism of gastric cancer metastasis is still not completely understood. Methods: Cells invasive activity was determined by invasion assay and HUVEC invasion assay. The association between DARPP-32 and CXCR4 was evaluated by immunofluorescence and co-immunoprecipitation assays. CXCR4 degradation was analyzed by Ubiquitination Assay. Results: Overexpression of DARPP-32 in AGS cells increased cell invasion with about as three-fold invasive cells as the vector control (p<0.01). As measured by HUVEC invasion assay, overexpression of DARPP-32 in AGS cells also had a significant increase in the invasive activity (p<0.001). We found that DARPP-32 led to increased CXCR4 and MT1-MMP protein levels in DARPP-32 expressing AGS cells. The co-immunoprecipitation and immunofluorescence experiments demonstrated the existence of DARPP-32 and CXCR4 in the same protein complex. AGS cells expressing DARPP-32 displayed stable protein levels of CXCR4. IP-Western blot showed reduced ubiquitination of CXCR4 protein following the overexpression of DARPP-32 and treatment with CXCL-12, as compared to controls. Using AMD3100 (0.2 ng/ml) overnight blocked DARPP-32-induced cell invasion. The knockdown of endogenous DARPP-32 by lentiviral DARPP-32 shRNA in MKN-45 cell line reversed these signaling effects and decreased cell invasive activity, as measured by invasion and HUVEC invasion Assay (p<0.01, p<0.05). Conclusions: The in vitro studies indicate that DARPP-32 plays a role in invasion and metastasis; DARPP-32 promotes invasion and metastasis of gastric cancer cells by interacted with CXCR4, delaying CXCL-12-induced CXCR4 Ubiquitination and blocking CXCR4 degradation, activating MMP2 by increasing MT1-MMP expression. The in vivo experiments are ongoing to determine the efficacy of DARPP-32 in mediating CXCR4 overexpression and metastasis.


2012 ◽  
Vol 417 (2) ◽  
pp. 864-868 ◽  
Author(s):  
Xiaofei Lei ◽  
Xiaoguang Lv ◽  
Meng Liu ◽  
Zirong Yang ◽  
Mengyao Ji ◽  
...  

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e16555-e16555
Author(s):  
Beibei Chen ◽  
Saiqi Wang ◽  
Jinxi Huang ◽  
Jitian Li ◽  
Jianying Zhang ◽  
...  

e16555 Background: KREMEN2 is an important regulator of classical Wnt/β-catenin signaling pathway. However, the relationship between KREMEN2 and gastric cancer is not clear. The aim of this study was to explore the regulatory role of KREMEN2 in the tumorigenesis and metastasis of gastric cancer. Methods: We measured the protein level of KREMEN2 in 156 gastric adenocarcinoma, 40 metastatic gastric adenocarcinoma, 8 marginal and 4 normal tissues using tissue microarray. The differences in KREMEN2 expression were tested with Mann-Whitney U test. The relationship between KREMEN2 expression and pathologic data was determined with Pearson’s correlation analysis. The mRNA and protein level in cultured cell lines were detected by qRT-PCR and western blotting, respectively. Lentivirus was transfected by repressing KREMEN2. Cell viability was determined by the MTT assay. Apoptosis and cell cycle distribution were detected using flow cytometry. The cell migration was investigated by wound healing and transwell assay. Antibody array was performed to explore the underlying molecule mechanism. In vivo, Xenograft assay was established using nude mice to explore the role of KREMEN2 in gastric cancer cell and bioluminescence was observed via an in vivo imaging system. Results: It was demonstrated that, compared to para-cancerous tissues, KREMEN2 was significantly up-regulated in gastric cancer tissues, and was positively correlated with the pathological grade of gastric cancer patients. Given that KREMEN2 is abundantly expressed in most tested gastric cancer cell lines, KREMEN2 knockdown cell models were established and further used to construct mice xenograft model. After knocking down KREMEN2, the proliferation of gastric cancer cells was inhibited both in vivo and in vitro. At the same time, knockdown of KREMEN2 induced apoptosis, cell cycle arrest at G2/M phase and inhibition of migration in gastric cancer cells in vitro. Mechanistically, we found that knockdown of KREMEN2 suppressed PI3K/Akt pathway. Conclusions: Therefore, we revealed that the overexpression of KREMEN2 in gastric cancer may promote the carcinogenesis and metastasis of gastric cancer by activating the PI3K/Akt pathway.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Qing He ◽  
Ruiping Pang ◽  
Xin Song ◽  
Jie Chen ◽  
Huixin Chen ◽  
...  

Although thiazolidinediones (TZDs) were found to be ligands for peroxisome proliferators-activated receptorγ (PPARγ), the mechanism by which TZDs exert their anticancer effect remains unclear. Furthermore, the effect of TZDs on metastatic and angiogenesis potential of cancer cells is unknown. Our results in this paper show that rosiglitazone inhibited SGC-7901 gastric cancer cells growth, caused G1 cell cycle arrest and induced apoptosis in a dose-dependent manner. The effects of rosiglitazone on SGC-7901 cancer cells were completely reversed by treatment with PPARγ antagonist GW9662. Rosiglitazone inhibited SGC-7901 cell migration, invasiveness, and the expression of MMP-2 in dose-dependent manner via PPARγ-independent manner. Rosiglitazone reduced the VEGF induced angiogenesis of HUVEC in dose-dependent manner through PPARγ-dependent pathway. Moreover, rosiglitazone did not affect the expression of VEGF by SGC-7901 cells. Our results demonstrated that by PPARγ ligand, rosiglitazone inhibited growth and invasiveness of SGC-7901 gastric cancer cells and angiogenesis in vitro via PPARγ-dependent or -independent pathway.


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