Gemcitabine resistant pancreatic cancer cell lines acquire an invasive phenotype with collateral hypersensitivity to histone deacetylase inhibitors

Lin

Biotech and App Biochem

et al. 2017

Pancreatic cancer represents one of the most aggressive types of malignancy due to its high resistance toward most clinically available treatments. The presence of pancreatic cancer stem-like cells (CSCs) has been attributed to the intrinsically high resistance and highly metastatic potential of this disease. Here, we identified and isolated pancreatic CSCs using the side population (SP) method from human pancreatic cancer cell line, PANC-1. We then compared the SP and non-SP PANC-1 cells genetically. PANC-1 SP cells exhibited CSC properties including enhanced self-renewal ability, increased metastatic potential, and resistance toward gemcitabine treatment. These cancer stem-like phenotypes were supported by their enhanced expression of ABCG2, Oct4, and CD44. A traditional plant-derived antioxidant, garcinol, has been implicated for its anticancer properties. Here, we found that garcinol treatment to PANC-1 SP cells significantly suppressed the stem-like properties of PANC-1 SP cells and metastatic potential by downregulating the expression of Mcl-1, EZH2, ABCG2, Gli-1, and Notch1. More importantly, garcinol treatment led to the upregulation of several tumor suppressor microRNAs, and miR-200c increased by garcinol treatment was found to target and downregulate Notch1. Thus, PANC-1 SP cells may serve as a model for studying drug-resistant pancreatic CSCs, and garcinol has the potential as an antagonist against pancreatic CSCs.

Section: Discussionsupporting

confidence: 77%

Garcinol downregulates Notch1 signaling via modulating miR‐200c and suppresses oncogenic properties of PANC‐1 cancer stem‐like cells

Lin

Biotech and App Biochem

et al. 2017

“…The latter cell line shows similar invasive characteristics and morphology as seen in HepG2S1 cells although without the typical marker expression profile of EMT [25]. In vitro, monotherapy with acriflavine at increased dose, was cytotoxic for all cell lines tested.…”

Section: Resultsmentioning

confidence: 76%

“…Gene expression of the different lines was repeatedly determined over time by qRT-PCR and compared to transcriptome data of cells early after they were obtained from ATCC, this to monitor stability. The gemcitabine resistant human pancreatic cancer cell lines MiaPaCa-2 GR800 and their parental cell line MiaPaca-2 were a kind gift of Prof. T. Landowski [25] and were used to investigate the effect of ACF on drug sensitivity by XTT cell viability assay as described below.…”

Section: Methodsmentioning

confidence: 99%

Acriflavine Inhibits Acquired Drug Resistance by Blocking the Epithelial-to-Mesenchymal Transition and the Unfolded Protein Response

Dekervel

Bulle

Windmolders

et al. 2017

Translational Oncology

Epithelial-to-mesenchymal transition (EMT) is linked to tumor invasion, drug resistance and aggressive disease and this is largely dependent on the cell's microenvironment. Acriflavine (ACF) is an old antibacterial drug recently also suggested as anticancer agent and HIF inhibitor. We wanted to study the effect of acriflavine on EMT in different human cancer models. Pancreatic cancer cells (Panc-1) were exposed to TGF-β1 or cobalt chloride (to mimick severe hypoxia) to induce EMT. For our third model we exposed HepG2 liver cancer cells to sorafenib which resulted in development of acquired drug resistance with strong features of EMT and aggressive behavior. These models were morphologically and functionally (invasion assay) characterized. Markers of EMT were determined using qRT-PCR and Western blotting. Transcriptome analysis was performed following gene expression determination and combining the iRegulon tool and Gene Set Enrichment Analysis (GSEA). We made the following observations: (1) acriflavine inhibited EMT based on changes in cell morphology, invasive capacities and markers of EMT (at protein and gene expression level). (2) Transcriptome analysis revealed potent inhibition of ATF4 target genes and of the unfolded protein response. We showed that acriflavine blocked eIF2a phosphorylation and reduced ATF4 translation thereby inhibiting the PERK/eIF2a/ATF4 UPR pathway. (3) ACF restored drug sensitivity of cells that obtained acquired resistance. Conclusions: We identified acriflavine as a potent inhibitor of EMT and the UPR, thereby re-sensitizing the cancer cells to antineoplastic drugs.

Clinical Cancer Research

“…It has been reported that the selection of CDA overexpression in response to prolonged drug exposure is responsible for resistance to gemcitabine (18,43) and that the ectopic expression of CDA in CDA-deficient cancer cells leads to a significant increase in resistance to gemcitabine (18,44). We thus evaluated the functionality of the CDA protein produced after 5-Aza-dC treatment by breast and ovarian cancer cells, HCC-1954 and IGROV-1, respectively.…”

Section: Cda Is Downregulated By Dna Methylationmentioning

confidence: 99%

Cytidine Deaminase Deficiency Reveals New Therapeutic Opportunities against Cancer

Mameri

Bièche

Meseure

et al. 2017

One of the main challenges in cancer therapy is the identification of molecular mechanisms mediating resistance or sensitivity to treatment. Cytidine deaminase (CDA) was reported to be downregulated in cells derived from patients with Bloom syndrome, a genetic disease associated with a strong predisposition to a wide range of cancers. The purpose of this study was to determine whether CDA deficiency could be associated with tumors from the general population and could constitute a predictive marker of susceptibility to antitumor drugs. We analyzed expression, in large datasets for cancer cell lines and tumors and in various cancer cell lines and primary tumor tissues using IHC, PDXs, qRT-PCR, and Western blotting. We also studied the mechanism underlying CDA silencing and searched for molecules that might target specifically CDA-deficient tumor cells using analysis coupled to classical cellular experimental approaches. We found that CDA expression is downregulated in about 60% of cancer cells and tissues. We demonstrate that DNA methylation is a prevalent mechanism of CDA silencing in tumors. Finally, we show that CDA-deficient tumor cells can be specifically targeted with epigenetic treatments and with the anticancer drug aminoflavone. CDA expression status identifies new subgroups of cancers, and CDA deficiency appears to be a novel and relevant predictive marker of susceptibility to antitumor drugs, opening up new possibilities for treating cancer. .