scholarly journals PAK4 confers cisplatin resistance in gastric cancer cells via PI3K/Akt- and MEK/ERK-dependent pathways

2014 ◽  
Vol 34 (2) ◽  
Author(s):  
Xueqiong Fu ◽  
Jiarui Feng ◽  
Duan Zeng ◽  
Yu Ding ◽  
Changshou Yu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Mitogen Activated Protein Kinase ◽  
Concomitant Treatment ◽  
Gastric Cancer Cells ◽  
P21 Activated Kinase ◽  
Resistant Cells

CDDP [cisplatin or cis-diamminedichloroplatinum(II)] and CDDP-based combination chemotherapy have been confirmed effective against gastric cancer. However, CDDP efficiency is limited because of development of drug resistance. In this study, we found that PAK4 (p21-activated kinase 4) expression and activity were elevated in gastric cancer cells with acquired CDDP resistance (AGS/CDDP and MKN-45/CDDP) compared with their parental cells. Inhibition of PAK4 or knockdown of PAK4 expression by specific siRNA (small interfering RNA)-sensitized CDDP-resistant cells to CDDP and overcome CDDP resistance. Combination treatment of LY294002 [the inhibitor of PI3K (phosphoinositide 3-kinase)/Akt (protein kinase B or PKB) pathway] or PD98509 {the inhibitor of MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] pathway} with PF-3758309 (the PAK4 inhibitor) resulted in increased CDDP efficacy compared with LY294002 or PD98509 alone. However, after the concomitant treatment of LY294002 and PD98509, PF-3758309 administration exerted no additional enhancement of CDDP cytotoxicity in CDDP-resistant cells. Inhibition of PAK4 by PF-3758309 could significantly suppress MEK/ERK and PI3K/Akt signalling in CDDP-resistant cells. Furthermore, inhibition of PI3K/Akt pathway while not MEK/ERK pathway could inhibit PAK4 activity in these cells. The in vivo results were similar with those of in vitro. In conclusion, these results indicate that PAK4 confers CDDP resistance via the activation of MEK/ERK and PI3K/Akt pathways. PAK4 and PI3K/Akt pathways can reciprocally activate each other. Therefore, PAK4 may be a potential target for overcoming CDDP resistance in gastric cancer.

scholarly journals LncRNA UCA1 promotes development of gastric cancer via the miR-145/MYO6 axis

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
An Yang ◽  
Xin Liu ◽  
Ping Liu ◽  
Yunzhang Feng ◽  
Hongbo Liu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Cell Apoptosis ◽  
Gastric Cancer Cell ◽  
Gastric Cancer Cells ◽  
Gastric Cancer Cell Lines ◽  
Development Of Gastric Cancer

Abstract Background Long noncoding RNA (lncRNA), urothelial carcinoma-associated 1 (UCA1) is aberrantly expressed in multiple cancers and has been verified as an oncogene. However, the underlying mechanism of UCA1 in the development of gastric cancer is not fully understood. In the present study, we aimed to identify how UCA1 promotes gastric cancer development. Methods The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) data were used to analyze UCA1 and myosin VI (MYO6) expression in gastric cancer. Western blot and quantitative real-time PCR (QPCR) were performed to test the expression level of the UCA1/miR-145/MYO6 axis in gastric cancer cell lines and tissues. The roles of the UCA1/miR-145/MYO6 axis in gastric cancer in vitro and in vivo were investigated by CCK-8 assay, flow cytometry, siRNAs, immunohistochemistry, and a mouse xenograft model. The targeted relationship among UCA1, miR-145, and MYO6 was predicted using LncBase Predicted v.2 and TargetScan online software, and then verified by luciferase activity assay and RNA immunoprecipitation. Results UCA1 expression was higher but miR-145 expression was lower in gastric cancer cell lines or tissues, compared to the adjacent normal cell line or normal tissues. Function analysis verified that UCA1 promoted cell proliferation and inhibited cell apoptosis in the gastric cancer cells in vitro and in vivo. Mechanistically, UCA1 could bind directly to miR-145, and MYO6 was found to be a downstream target gene of miR-145. miR-145 mimics or MYO6 siRNAs could partly reverse the effect of UCA1 on gastric cancer cells. Conclusions UCA1 accelerated cell proliferation and inhibited cell apoptosis through sponging miR-145 to upregulate MYO6 expression in gastric cancer, indicating that the UCA1/miR-145/MYO6 axis may serve as a potential therapeutic target for gastric cancer.

scholarly journals CDK10 Regulates Gastric Cancer Metastasis By Inhibiting lncRNA-C5ORF42-5 Via Phosphorylation Level of AKT/ERK

2021 ◽  
Author(s):  
Zi-Jian Deng ◽  
Dong-Wen Chen ◽  
Xi-Jie Chen ◽  
Jia-Ming Fang ◽  
Liang Xv ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Cell Line ◽  
High Throughput ◽  
Cancer Metastasis ◽  
High Throughput Sequencing ◽  
Gastric Cancer Cells ◽  
Related Proteins

Abstract Background: Gastric cancer is the fourth most common malignant disease. Both CDK10 and long noncoding RNAs (lncRNAs) have been found to exert biological functions in multiple cancers. However, it is still unclear whether CDK10 represses tumor progression in gastric cancer by reducing potential targeting lncRNAs.Methods: The functions of CDK10 and lncRNA-C5ORF42-5 in proliferation, invasion and migration were assessed by MTS assays, colony formation assays, cell cycle and apoptosis assays, Transwell assays, wound healing assays and animal experiments. We used high-throughput sequencing to confirm the existence of lncRNA-C5ORF42-5 and quantitative real-time PCR was used to evaluate lncRNA expression. Then, with RNA-seq sequencing as well as GO function and KEGG enrichment analysis, we identified the signaling pathways in which lncRNA-C5ORF42-5 was involved in gastric cancer. Finally, western blotting was used to identify the genes regulated by lncRNA-C5ORF42-5.Results: Our results showed that CDK10 is expressed at relatively low levels in gastric cancer cell lines and inhibits the progression of gastric cancer cells both in vitro and in vivo. Next, based on high-throughput sequencing, we identified a novel lncRNA, lncRNA-C5ORF42-5, in the stable CDK10-overexpressing cell line compared with the CDK-knockdown cell line and their controls. Additionally, we confirmed that lncRNA-C5ORF42-5 acts as an oncogene to promote metastasis in gastric cancer in vitro and in vivo. We then ascertained that lncRNA-C5ORF42-5 is a major contributor to the function of CDK10 in gastric cancer metastasis by upregulating lncRNA-C5ORF42-5 to reverse the effects of CDK10 overexpression. Finally, we explored the mechanism by which lncRNA-C5ORF42-5 overexpression affects gastric cancer cells to elucidate whether lncRNA-C5ORF42-5 may increase the activity of the SMAD pathway of BMP signaling and promote the expression of EMT-related proteins, such as E-cadherin. Additionally, overexpression of lncRNA-C5ORF42-5 affected the phosphorylation levels of AKT and ERK.Conclusion: Our findings suggest that CDK10 overexpression represses gastric cancer tumor progression by reducing lncRNA-C5ORF42-5 and hindering activation of the related proteins in metastatic signaling pathways, which provides new insight into developing effective therapeutic strategies in the treatment of metastatic gastric cancer.

scholarly journals Apelin Over-Expression Promotes Proliferation and Angiogenesis of Gastric Cancer Cells

2021 ◽  
Author(s):  
Li-Jun Tian ◽  
Hong-Zhi Liu ◽  
Qiang Zhang ◽  
Dian-Zhong Geng ◽  
Jing Yang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cyclin D1 ◽  
Cancer Cells ◽  
Signaling Pathway ◽  
Cox Regression ◽  
Gastric Cancer Cells ◽  
Over Expression ◽  
Normal Tissues

Abstract Background: Apelin is a recently identified endogenous ligand associated with proliferation and angiogenesis of several cancers. However, only few studies have reported on the functions and the role of apelin in gastric cancer (GC). Therefore, in the present study, we investigated the association and the mechanisms underlying Apelin expression and proliferation of GC cells both in vitro and in vivo.Methods: We enrolled 178 postoperative care GC patients to investigate clinicopathological and immunohistochemical factors associated with Apelin expression. The relationship between Survival of patients and apelin expression was evaluated using Kaplan-Meier method and Cox regression analyses. The expression of apelin mRNA and its proteins in GC tissues and cell lines were analyzed using quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR), western blot and ELISA. The role and mechanisms underlying regulation of Apelin expression in human GC cells were evaluated through several in vitro and in vivo experiments. Results: Apelin was over expressed in human GC cells, relative to adjacent normal tissues. The over expression of apelin was associated with vessel invasion (P <0.01), lymph node metastasis (P <0.01), late-staged tumor (T) (P <0.05), worse pathological type (P <0.05), nerve invasion (P <0.05). In addition, expression of apelin strongly and positively correlated with that of vascular endothelial growth factor (VEGF). Over-expression of apelin promoted proliferation and invasion of MGC-803 cell via the ERK/Cyclin D1/MMP-9 signaling pathway. Apelin over-expression also promoted angiogenesis of GC cells, accelerating growth of subcutaneous xenograft of the cancer cells in vivo.Conclusions: Over-expression of apelin promotes proliferation and metastasis of GC cells via the ERK/Cyclin D1/MMP-9 signaling pathway and is associated with adverse events of the cancer. Consequently, apelin is a potential therapeutic target for human GC.

Oleanolic acid induces autophagic death in human gastric cancer cells in vitro and in vivo

2016 ◽  
Vol 40 (7) ◽  
pp. 770-778 ◽  
Author(s):  
Hao Nie ◽  
Yu Wang ◽  
Yong Qin ◽  
Xing-Guo Gong
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Oleanolic Acid ◽  
Human Gastric Cancer ◽  
Gastric Cancer Cells

Downregulation of CCKBR Expression Inhibits the Proliferation of Gastric Cancer Cells, Revealing a Potential Target for Immunotoxin Therapy

2022 ◽  
Vol 22 ◽  
Author(s):  
Meng Li ◽  
Jiang Chang ◽  
Honglin Ren ◽  
Defeng Song ◽  
Jian Guo ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Cell Counting ◽  
Migration And Invasion ◽  
Gastric Cancer Cells ◽  
Aberrant Expression ◽  
Promising Target ◽  
The Impact

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.

scholarly journals PRKAA1 Promotes Proliferation and Inhibits Apoptosis of Gastric Cancer Cells Through Activating JNK1 and Akt Pathways

2020 ◽  
Vol 28 (3) ◽  
pp. 213-223 ◽  
Author(s):  
Yangmei Zhang ◽  
Xichang Zhou ◽  
Long Cheng ◽  
Xiang Wang ◽  
Qinglin Zhang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Akt Signaling ◽  
Catalytic Subunit ◽  
Gastric Cancer Cells ◽  
In Vivo Experiments ◽  
Compound C ◽  
Amp Activated Protein Kinase

PRKAA1 (protein kinase AMP-activated catalytic subunit α 1) is a catalytic subunit of AMP-activated protein kinase (AMPK), which plays a key role in regulating cellular energy metabolism through phosphorylation, and genetic variations in the PRKAA1 have been found to be associated with gastric cancer risk. However, the effect and underlying molecular mechanism of PRKAA1 on gastric cancer tumorigenesis, especially the proliferation and apoptosis, are not fully understood. Our data showed that PRKAA1 is highly expressed in BGC-823 and MKN45 cells and is expressed low in SGC-7901 and MGC-803 cells in comparison with the other gastric cancer cells. PRKAA1 downregulation by shRNA or treatment of AMPK inhibitor compound C significantly inhibited proliferation as well as promoted cell cycle arrest and apoptosis of BGC-823 and MKN45 cells. Moreover, the expression of PCNA and Bcl-2 and the activity of JNK1 and Akt signaling were also reduced in BGC-823 and MKN45 cells after PRKAA1 downregulation. In vivo experiments demonstrated that tumor growth in nude mice was significantly inhibited after PRKAA1 silencing. Importantly, inactivation of JNK1 or Akt signaling pathway significantly inhibited PRKAA1 overexpression-induced increased cell proliferation and decreased cell apoptosis in MGC-803 cells. In conclusion, our findings suggest that PRKAA1 increases proliferation and restrains apoptosis of gastric cancer cells through activating JNK1 and Akt pathways.

DT-13 synergistically potentiates the sensitivity of gastric cancer cells to topotecan via cell cycle arrest in vitro and in vivo

2018 ◽  
Vol 818 ◽  
pp. 124-131 ◽  
Author(s):  
Hongzhi Du ◽  
Yang Liu ◽  
Xudong Chen ◽  
Xiaowen Yu ◽  
Xiaoying Hou ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Cancer Cells ◽  
Gastric Cancer Cells ◽  
Cycle Arrest

scholarly journals TSPAN9 suppresses the chemosensitivity of gastric cancer to 5-fluorouracil by promoting autophagy

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yaoyue Qi ◽  
Weiwei Qi ◽  
Shihai Liu ◽  
Libin Sun ◽  
Aiping Ding ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Transmembrane Protein ◽  
Pi3k Pathway ◽  
Drug Resistant ◽  
Gastric Cancer Cells ◽  
Autophagy Pathway ◽  
Resistant Cells

Abstract Background The issue of drug resistance in gastric cancer has attracted global attention. TSPAN9, a 4-transmembrane protein that plays an important role in tumor progression and signal transduction, has been found to be closely related to tumor invasion, metastasis, and autophagy. Methods Immunoblotting was used to evaluate TSPAN9 expression in parental and drug-resistant gastric cancer cells. Functional assays, such as the CCK-8 assay, were used to detect the proliferation of gastric cancer cells and the response of TSPAN9 to 5-fluorouracil (5-FU). Western blotting was used to analyze the expression of constituents of the PI3K/AKT/mTOR-mediated autophagy pathway induced by TSPAN9. Coimmunoprecipitation was performed to assess the specific mechanism by which TSPAN9 affects the PI3K pathway. Results We demonstrated that TSPAN9 is overexpressed in 5-FU-resistant cells compared to parental cells. 5-FU-mediated inhibition of cell proliferation can be significantly restored by increasing TSPAN9 expression, and inhibiting this expression in drug-resistant cells can restore the sensitivity of the cells to 5-FU. In addition, TSPAN9 also significantly promoted autophagy in gastric cancer cells in vitro. Further studies indicated that TSPAN9 downregulates the expression of PI3K and proteins associated with PI3K-mediated autophagy. In addition, TSPAN9 interacts with PI3K and inhibits its catalytic activity. Conclusion The current study reveals the important role of TSPAN9 in drug resistance to 5-FU in gastric cancer. It also provides a new target to clinically address drug-resistant gastric cancer and will contribute to the treatment strategy of this disease.

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