scholarly journals Exosomes derived from cancer stem cells of gemcitabine-resistant pancreatic cancer cells enhance drug resistance by delivering miR-210

2019 ◽  
Vol 43 (1) ◽  
pp. 123-136 ◽  
Author(s):  
Zhiyong Yang ◽  
Ning Zhao ◽  
Jing Cui ◽  
Heshui Wu ◽  
Jiongxin Xiong ◽  
...  

Abstract Purpose Gemcitabine (GEM)-based chemotherapy is the first-line treatment for locally advanced pancreatic cancer. GEM resistance, however, remains a significant clinical challenge. Here, we investigated whether exosomes derived from GEM-resistant pancreatic cancer stem cells (CSCs) mediate cell-cell communication between cells that are sensitive or resistant to GEM and, by doing so, regulate drug resistance. Methods GEM-sensitive BxPC-3-derived BxS and PANC-1 pancreatic cancer cells were cultured with exosomes extracted from CSCs isolated from GEM-resistant BxPC-3-derived BxR cells (BxR-CSC). The effect of exosomes on drug resistance, cell cycle progression, apoptosis and miRNA expression was evaluated in BxS and PANC-1 cells. Relevant miRNAs associated with GEM resistance were identified and the role of miR-210 in conferring drug resistance was examined in vitro and in vivo. Results BxR-CSC-derived exosomes induced GEM resistance, inhibited GEM-induced cell cycle arrest, antagonized GEM-induced apoptosis, and promoted tube formation and cell migration in BxS and PANC-1 cells. Elevated miR-210 expression levels were detected in BxR-CSCs and BxR-CSC-derived exosomes compared to those in BxS-CSCs and BxS-CSC-derived exosomes. In addition, increased expression levels of miR-210 were observed in BxS and PANC-1 cells cultured with BxR-CSC-derived exosomes upon exposure to GEM in a dose-dependent manner. Also, a series of biological changes was observed in BxS cells after transfection with miR-210 mimics, including activation of the mammalian target of rapamycin (mTOR) signaling pathway, and these changes were similar to those triggered by BxR-CSC-derived exosomes. Conclusions Our findings suggest that exosomes derived from GEM-resistant pancreatic cancer stem cells mediate the horizontal transfer of drug-resistant traits to GEM-sensitive pancreatic cancer cells by delivering miR-210.

2008 ◽  
Vol 26 (17) ◽  
pp. 2806-2812 ◽  
Author(s):  
Cheong J. Lee ◽  
Joseph Dosch ◽  
Diane M. Simeone

Cellular heterogeneity in cancer was observed decades ago by studies in mice which showed that distinct subpopulations of cells within a tumor mass are capable of driving tumorigenesis. Conceptualized from this finding was the stem-cell hypothesis for cancer, which suggests that only a specific subset of cancer cells within each tumor is responsible for tumor initiation and propagation, termed tumor initiating cells or cancer stem cells (CSCs). Recent data has been provided to support the existence of CSCs in human blood cell–derived cancers and solid organ tumors of the breast, brain, prostate, colon, and skin. Study of human pancreatic cancers has also revealed a specific subpopulation of cancer cells that possess the characteristics of CSCs. These pancreatic cancer stem cells express the cell surface markers CD44, CD24, and epithelial-specific antigen, and represent 0.5% to 1.0% of all pancreatic cancer cells. Along with the properties of self-renewal and multilineage differentiation, pancreatic CSCs display upregulation of important developmental genes that maintain self-renewal in normal stem cells, including Sonic hedgehog (SHH) and BMI-1. Signaling cascades that are integral in tumor metastasis are also upregulated in the pancreatic CSC. Understanding the biologic behavior and the molecular pathways that regulate growth, survival, and metastasis of pancreatic CSCs will help to identify novel therapeutic approaches to treat this dismal disease.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e14591-e14591 ◽  
Author(s):  
George P. Sorescu ◽  
Lora W. Forman ◽  
Douglas V. Faller

e14591 Background: 93% of pancreatic cancers have activating mutations in the K-Ras gene. We have previously shown that mutated, constitutively-activated Ras is lethal to cells if an essential Ras-driven survival pathway is disrupted by suppression of PKCδ. PKCδ has various cellular functions, but is not required for the survival of normal cells and its inhibition in vitro or in vivo has no known adverse effects. Signal transducer and activator of transcription 3 (STAT3) is constitutive driver of many solid cancers, including pancreatic cancers. STAT3 requires phosphorylation of Tyr 705 for activation and, once activated translocates to the nucleus, where it controls genes involved in cell survival or death. Methods: Human pancreatic cancer cell lines PancI, MIAPACA and primary human pancreatic cancer stem cells were studied. shRNA-mediated knockdown of PKCδ, with scrambled shRNA as a control, was used to validate PKCδ as a target. Rottlerin and KAM1 were used as relatively specific PKCδ inhibitors. For inhibition of STAT3, specific shRNA against STAT3 versus scrambled shRNA were employed for knock-downs. For cytotoxicity analyses, MTS assays were used to assess cell growth. Z-vad-FMK was used as a pan-caspase inhibitor. Immunoblotting was used to verify knock-down of PKCδ or STAT3 and to quantify the phosphorylation status of STAT3 phospho-Tyr 705. Results: PKCδ inhibition by either shRNA knock-down or inhibitor led to dephosphorylation of STAT3 at Tyr 705, extensive cytotoxicity of pancreatic cancer cells and dramatic reductions in tumor clonogenic capacity. Knock down of STAT3 was equally cytotoxic to pancreatic cancer cells. Cytotoxicity following PKCδ inhibition was not prevented by a pan-caspase inhibitor. Conclusions: Activated STAT3 and survival in pancreatic cancer cells requires PKCδ. Inhibition of PKCδ, and subsequent suppression of STAT3 activation, is cytotoxic for pancreatic cancer cells through a mechanism independent of caspase activation or apoptosis. Small molecule inhibitors of PKCδ have potential as targeted therapeutic agents against pancreatic tumors, pancreatic cancer stem cells, and other human tumors with mutational activation of Ras.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Sabrina Bimonte ◽  
Antonio Barbieri ◽  
Maddalena Leongito ◽  
Giuseppe Palma ◽  
Vitale del Vecchio ◽  
...  

Pancreatic ductal adenocarcinoma is currently one of the deadliest cancers with low overall survival rate. This disease leads to an aggressive local invasion and early metastases and is poorly responsive to treatment with chemotherapy or chemoradiotherapy. Several studies have shown that pancreatic cancer stem cells (PCSCs) play different roles in the regulation of drug resistance and recurrence in pancreatic cancer. MicroRNA (miRNA), a class of newly emerging small noncoding RNAs, is involved in the modulation of several biological activities ranging from invasion to metastases development, as well as drug resistance of pancreatic cancer. In this review, we synthesize the latest findings on the role of miRNAs in regulating different biological properties of pancreatic cancer stem cells.


Cell Cycle ◽  
2018 ◽  
Vol 17 (12) ◽  
pp. 1487-1495
Author(s):  
Zhengyan Xu ◽  
Yanjun Jia ◽  
Xiaoxi Huang ◽  
Nianhua Feng ◽  
Ying Li

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