The association of an exosomal form of PD-L1 with immunosuppressive activity and gastric cancer prognosis.

2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 47-47
Author(s):  
Yibo Fan ◽  
Xiaofang Che ◽  
Zhi Li ◽  
Xiujuan Qu ◽  
Yunpeng Liu

47 Background: The greatest challenge in cancer immunotherapy is to identify efficient predictive biomarkers to select patients for treatment. Though tumor cell membrane PD-L1 has been most anticipated, tumor cell membrane PD-L1 does not correlate with higher response rates and predict for clinical benefit. Subsequently studies showed that the prognostic value of tumor cell membrane PD-L1 in cancer patients remains controversial. In addition to membrane-associated PD-L1, tumor cell also secreted extracellular soluble PD-L1 in the microenvironment. However, even if extracellular soluble PD-L1 was detected, it did not solve the problem mentioned above. In the present study, we discovered another form of PD-L1 in extracellular microenvironment in cancer cells, that is exosomal PD-L1. However, the predictive role and the effect of tumor-derived exosomal PD-L1 is unclear. Methods: We evaluated the prognostic value of exosomal PD-L1 in the plasma of gastric cancer patients by ELISA and the effect of exosomal PD-L1-derived from gastric cancer cell lines by Western blot and Flow cytometry analysis. Results: Exosomal PD-L1 was detected in plasma samples from 69 gastric cancer patients, and exosomal PD-L1 content was significantly associated with T stage (P = 0.012). Overall Survival was significantly lower in the high exosomal PD-L1 group (p = 0.021). Additionally, gastric cancer cells also secreted exosomal PD-L1, with the amounts positively associated with PD-L1 amounts in the corresponding gastric cancer cell lines. Besides, exosomal PD-L1 was more stable and showed stronger immunosuppressive effects in the microenvironment compared with soluble PD-L1. Conclusions: Exosomal PD-L1 might predict the survival in gastric cancer, and induces higher T-cell apoptosis levels compared with soluble PD-L1.

Author(s):  
Jianmiao WANG ◽  
Jing YANG ◽  
Ji QIU ◽  
Taoyan SONG

Background: We aimed to investigate the relationship between miR-596, BCL-2, and apoptosis of gastric cancer cells, and to explore the mechanism of miR-596 in gastric cancer. Besides, this study aimed to find the target of miR-596 and explore the mechanism of action of miR-596 in gastric cancer. Methods: Eighteen samples of gastric cancer tissues and 18 samples of corresponding tumor-adjacent tissues were collected from 18 gastric cancer patients (aged from 40 to 55 yr) admitted to Zhuji People's Hospital, Zhuji, China from March 2017 to May 2018. The expression levels of miR-596 and BCL-2 were detected to verify the regulation of miR-596 on the apoptosis and proliferation of gastric cancer cell lines MKN-45 and HGC-27 and its effect on BCL-2 expression. Results: The expression level of miR-596 was notably lower in gastric cancer tissues than in adjacent tissues, and BCL-2 level was notably higher in gastric cancer tissues than in adjacent tissues. After the up-regulation of miR-596 expression, the proliferation of MKN-45 and HGC-27 cells was significantly decreased, the level of apoptosis was significantly increased (P<0.05), and the expression of BCL-2 was decreased. The dual-luciferase report showed that miR-596 had a targeting inhibition of BCL-2. Gastric cancer cells with up-regulated miR596 and BCL-2 had significantly higher proliferation and lower apoptosis than cells with up-regulated miR-596. Conclusions: miR-596 can inhibit the proliferation of gastric cancer cells and promote the apoptosis through its targeting inhibition of BCL-2 expression.


1989 ◽  
Vol 28 (1) ◽  
pp. 43-47
Author(s):  
Yasuo IITSUKA ◽  
Shizuko ITOHARA ◽  
Setsujo SHIOTA ◽  
Takao MATSUI ◽  
Yasuaki HIROOKA ◽  
...  

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
An Yang ◽  
Xin Liu ◽  
Ping Liu ◽  
Yunzhang Feng ◽  
Hongbo Liu ◽  
...  

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.


2009 ◽  
Vol 99 (7) ◽  
pp. 395-401 ◽  
Author(s):  
Jun Chul Park ◽  
Yong Chan Lee ◽  
Jie-Hyun Kim ◽  
Yu Jin Kim ◽  
Sang Kil Lee ◽  
...  

2018 ◽  
Vol 19 (11) ◽  
pp. 3616 ◽  
Author(s):  
Rui Wang ◽  
Xiaoyan Deng ◽  
Chengfu Yuan ◽  
Hongmei Xin ◽  
Geli Liu ◽  
...  

The assembly and maintenance of cilia depend on intraflagellar transport (IFT) proteins, which play an important role in development and homeostasis. IFT80 is a newly defined IFT protein and partial mutation of IFT80 in humans causes diseases such as Jeune asphyxiating thoracic dystrophy (JATD) and short rib polydactyly (SRP) type III, both characterized by abnormal skeletal development. However, the role and mechanism of IFT80 in the invasion of gastric cancer is unknown. We established SGC-7901 and MKN-45 gastric cancer cell lines that stably overexpressed IFT80, as verified by quantitative reverse transcription-PCR, Western blot, and immunofluorescence. Matrix metalloproteinase-9 (MMP9) plays an important role in tumor invasion, and its expression was assessed by quantitative reverse transcription-PCR, Western blotting, and immunofluorescence. The invasion ability of IFT80 on SGC-7901 and MKN-45 cells was examined by the Matrigel invasion assay. The relationship between p75NGFR, and the p75NGFR antagonists, PD90780 and IFT80, were detected by quantitative reverse transcription-PCR and Western blotting. We first detected an IFT80 expression pattern, and found that IFT80 was highly expressed in gastric cancer clinical samples. Overexpression of IFT80 in the gastric cancer cell lines, SGC-7901 and MKN-45, led to lengthening cilia. Additionally, overexpression of IFT80 significantly improved proliferation and invasion, but inhibited apoptosis, in gastric cancer cells. We further found that overexpression of IFT80 increased p75NGFR and MMP9 mRNA and protein expression. Treatment with the p75NGFR antagonist PD90780 inhibited the increased invasion ability resulting from overexpression of IFT80 in SGC-7901 and MKN-45 gastric cancer cells. Thus, these results suggest that IFT80 plays an important role in invasion of gastric cancer through regulating the ift80/p75NGFR/MMP9 signal pathways.


2015 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Shang-Jin Peng ◽  
Jue-Wei Chen

<p class="Abstract">The present study investigates the effect of rubriflordilactone A on the viability and its underlying mechanism in gastric cancer cell lines (SNU-1 and SNU-5) and normal gastric epithelial cell line (GES‑1). Incubation of the gastric cancer and non cancer cell lines in acidic media led to reduction in the viability of the non cancer cells without any effect on cancer cells. Apoptosis in SNU-1 and SNU-5 cells was induced on exposure to rubriflordilactone A after 48 hours compared to the control cells (p&lt;0.01). The percentage of apoptosis in SNU-1 and SNU-5 cells on exposure to rubriflordilactone A was 79.3 ± 4.7 and 74.0 ± 5.1, respectively after 48 hours. Exposure of SNU-1 and SNU-5 cancer cell lines to rubriflordilactone A at a concentration of 10 μM in media with acidic pH decreased phosphorylation of ERK ½. The similar reduction was caused by ERK 1/2 phosphorylation inhibition, PD98059. Thus rubriflordilactone A reduces viability of gastric cancer cell lines by inducing apoptosis through the reduction of ERK 1/2 phosphorylation.</p><p> </p>


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