scholarly journals The Tobacco Metabolite NNK Enhances Pancreatic Cancer Cell Stemness and Chemoresistance by Activating the β2AR-Akt Autophagy Axis

Author(s):  
Xin Chen ◽  
Weifan Zhang ◽  
Rujuan Liu ◽  
Zeen Zhu ◽  
Mengyuan Gong ◽  
...  

Abstract Background: Low responsiveness to chemotherapy is an important cause of poor prognosis in pancreatic cancer. Smoking is a high-risk factor for pancreatic cancer and its resistance to gemcitabine; however, the underlying mechanisms remain unclear. 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is the main metabolite of tobacco burning and has been shown to be associated with cancer development and chemoresistance, but in pancreatic cancer, its mechanism remains poorly understood.Methods: The effect of NNK on pancreatic cancer cell viability was confirmed by using Cell Counting Kit-8 and colony formation assays. Stem cell sphere formation assays and western blotting/qPCR measurements of stemness-related molecules were used to detect pancreatic cancer cell stemness. The pancreatic cancer autophagy status was evaluated by immunofluorescence staining of LC3 and western blotting/qPCR analysis of autophagy-related molecules.Results: NNK promoted stemness and gemcitabine resistance in pancreatic cancer cell lines. Furthermore, NNK intervention increased autophagy and changed the expression levels of autophagy-related markers, which preliminarily confirmed the activation of autophagy by NNK. Finally, the results showed that NNK-promoted stemness, and gemcitabine resistance was activated by the autophagy pathway, which was mediated by the β2AR-Akt signalling pathway.Conclusions: Autophagy induced by activating the NNK-induced β2AR-Akt signalling pathway promoted stemness and gemcitabine resistance in pancreatic cancer cells.

2021 ◽  
Author(s):  
Xin Chen ◽  
Weifan Zhang ◽  
Rujuan Liu ◽  
Zeen Zhu ◽  
Mengyuan Gong ◽  
...  

Abstract Background: Low responsiveness to chemotherapy is an important cause of poor prognosis in pancreatic cancer. Smoking is a high-risk factor for pancreatic cancer and its resistance to gemcitabine; however, the underlying mechanisms remain unclear. 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is the main metabolite of tobacco burning and has been shown to be associated with cancer development and chemoresistance, but in pancreatic cancer, its mechanism remains poorly understood.Methods: The effect of NNK on pancreatic cancer cell viability was confirmed by using Cell Counting Kit-8 and colony formation assays. Stem cell sphere formation assays and western blotting/qPCR measurements of stemness-related molecules were used to detect pancreatic cancer cell stemness. The pancreatic cancer autophagy status was evaluated by immunofluorescence staining of LC3 and western blotting/qPCR analysis of autophagy-related molecules.Results: NNK promoted stemness and gemcitabine resistance in pancreatic cancer cell lines. Furthermore, NNK intervention increased autophagy and changed the expression levels of autophagy-related markers, which preliminarily confirmed the activation of autophagy by NNK. Finally, the results showed that NNK-promoted stemness, and gemcitabine resistance was activated by the autophagy pathway, which was mediated by the β2AR-Akt signalling pathway.Conclusions: Autophagy induced by activating the NNK-induced β2AR-Akt signalling pathway promoted stemness and gemcitabine resistance in pancreatic cancer cells.


Biomedicines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 149
Author(s):  
David J. Wooten ◽  
Indu Sinha ◽  
Raghu Sinha

Survival rate for pancreatic cancer remains poor and newer treatments are urgently required. Selenium, an essential trace element, offers protection against several cancer types and has not been explored much against pancreatic cancer specifically in combination with known chemotherapeutic agents. The present study was designed to investigate selenium and Gemcitabine at varying doses alone and in combination in established pancreatic cancer cell lines growing in 2D as well as 3D platforms. Comparison of multi-dimensional synergy of combinations’ (MuSyc) model and highest single agent (HSA) model provided quantitative insights into how much better the combination performed than either compound tested alone in a 2D versus 3D growth of pancreatic cancer cell lines. The outcomes of the study further showed promise in combining selenium and Gemcitabine when evaluated for apoptosis, proliferation, and ENT1 protein expression, specifically in BxPC-3 pancreatic cancer cells in vitro.


2021 ◽  
Vol 11 ◽  
Author(s):  
Congjun Zhang ◽  
Shuangyan Ou ◽  
Yuan Zhou ◽  
Pei Liu ◽  
Peiying Zhang ◽  
...  

ObjectivePancreatic cancer is one of the most lethal human malignancies. Gemcitabine is widely used to treat pancreatic cancer, and the resistance to chemotherapy is the major difficulty in treating the disease. N6-methyladenosine (m6A) modification, which regulates RNA splicing, stability, translocation, and translation, plays critical roles in cancer physiological and pathological processes. METTL14, an m6A Lmethyltransferase, was found deregulated in multiple cancer types. However, its role in gemcitabine resistance in pancreatic cancer remains elusive.MethodsThe mRNA and protein level of m6A modification associated genes were assessed by QRT-PCR and western blotting. Then, gemcitabine‐resistant pancreatic cancer cells were established. The growth of pancreatic cancer cells were analyzed using CCK8 assay and colony formation assay. METTL14 was depleted by using shRNA. The binding of p65 on METTL14 promoter was assessed by chromatin immunoprecipitation (ChIP) assay. Protein level of deoxycytidine kinase (DCK) and cytidine deaminase (CDA) was evaluated by western blotting. In vivo experiments were conducted to further confirm the critical role of METTL14 in gemcitabine resistance.ResultsWe found that gemcitabine treatment significantly increased the expression of m6A methyltransferase METTL14, and METTL14 was up-regulated in gemcitabine-resistance human pancreatic cancer cells. Suppression of METTL14 obviously increased the sensitivity of gemcitabine in resistant cells. Moreover, we identified that transcriptional factor p65 targeted the promoter region of METTL14 and up-regulated its expression, which then increased the expression of cytidine deaminase (CDA), an enzyme inactivates gemcitabine. Furthermore, in vivo experiment showed that depletion of METTL14 rescue the response of resistance cell to gemcitabine in a xenograft model.ConclusionOur study suggested that METTL14 is a potential target for chemotherapy resistance in pancreatic cancer.


2019 ◽  
Vol 19 (5) ◽  
pp. 417-427 ◽  
Author(s):  
Xiang Chen ◽  
Jilai Tian ◽  
Gloria H. Su ◽  
Jiayuh Lin

Background:Elevated production of the pro-inflammatory cytokine interleukin-6 (IL-6) and dysfunction of IL-6 signaling promotes tumorigenesis and are associated with poor survival outcomes in multiple cancer types. Recent studies showed that the IL-6/GP130/STAT3 signaling pathway plays a pivotal role in pancreatic cancer development and maintenance.Objective:We aim to develop effective treatments through inhibition of IL-6/GP130 signaling in pancreatic cancer.Methods:The effects on cell viability and cell proliferation were measured by MTT and BrdU assays, respectively. The effects on glycolysis was determined by cell-based assays to measure lactate levels. Protein expression changes were evaluated by western blotting and immunoprecipitation. siRNA transfection was used to knock down estrogen receptor α gene expression. Colony forming ability was determined by colony forming cell assay.Results:We demonstrated that IL-6 can induce pancreatic cancer cell viability/proliferation and glycolysis. We also showed that a repurposing FDA-approved drug bazedoxifene could inhibit the IL-6/IL-6R/GP130 complexes. Bazedoxifene also inhibited JAK1 binding to IL-6/IL-6R/GP130 complexes and STAT3 phosphorylation. In addition, bazedoxifene impeded IL-6 mediated cell viability/ proliferation and glycolysis in pancreatic cancer cells. Consistently, other IL-6/GP130 inhibitors SC144 and evista showed similar inhibition of IL-6 stimulated cell viability, cell proliferation and glycolysis. Furthermore, all three IL-6/GP130 inhibitors reduced the colony forming ability in pancreatic cancer cells.Conclusion:Our findings demonstrated that IL-6 stimulates pancreatic cancer cell proliferation, survival and glycolysis, and supported persistent IL-6 signaling is a viable therapeutic target for pancreatic cancer using IL-6/GP130 inhibitors.


PLoS ONE ◽  
2010 ◽  
Vol 5 (11) ◽  
pp. e15455 ◽  
Author(s):  
Timothy K. Williams ◽  
Christina L. Costantino ◽  
Nikolai A. Bildzukewicz ◽  
Nathan G. Richards ◽  
David W. Rittenhouse ◽  
...  

Cancers ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 142 ◽  
Author(s):  
Omar Elaskalani ◽  
Marco Falasca ◽  
Niamh Moran ◽  
Michael Berndt ◽  
Pat Metharom

1994 ◽  
Vol 266 (1) ◽  
pp. R277-R283 ◽  
Author(s):  
J. P. Smith ◽  
G. Liu ◽  
V. Soundararajan ◽  
P. J. McLaughlin ◽  
I. S. Zagon

The gastrointestinal peptide cholecystokinin (CCK) is known to stimulate growth of human pancreatic cancer in a receptor-mediated fashion. The purpose of this study was to characterize the receptor responsible for the trophic effects of CCK in cancer cells. With the use of homogenates of PANC-1 human pancreatic cancer cells grown in vitro, the binding characteristics and optimal conditions of radiolabeled selective CCK-receptor antagonists ([3H]L-365,260 and [3H]L-364,718) were examined. Specific and saturable binding was detected with [3H]L-365,260, and Scatchard analysis revealed that the data were consistent for a single site of binding with a binding affinity of 4.3 +/- 0.6 nM and a binding capacity (Bmax) of 283 +/- 68 fmol/mg protein in log phase cells. Binding was dependent on protein concentration, time, temperature, and pH and was sensitive to Na+, K+, Mg2+, and ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. In contrast to log phase cells, Bmax decreased by 80 and 92% in confluent and postconfluent cultures, respectively. Subcellular fractionation studies revealed that binding was in the membrane fraction. Competition experiments indicated that L-365,260 and gastrin were more effective at displacing the radiolabeled L-365,260 than CCK. No binding was detected with the CCK-A antagonist [3H]L-364,718. Assays performed with [3H]L-365,260 on five additional human pancreatic cancer cell lines in vitro and tumor tissue from xenografts in nude mice also revealed specific and saturable binding. These results provide the first identification of a CCK-B/gastrin receptor in human pancreatic cancer cells and tumors and explain the effects of CCK on the growth of this malignancy.


2005 ◽  
Vol 20 (4) ◽  
pp. 235-241 ◽  
Author(s):  
E. Greco ◽  
D. Basso ◽  
P. Fogar ◽  
S. Mazza ◽  
F. Navaglia ◽  
...  

Background We investigated in vitro whether IL-1β and TGF-β1 affect pancreatic cancer cell growth, adhesion to the extracellular matrix and Matrigel invasion. Materials and methods Adhesion to fibronectin, laminin and type I collagen, and Matrigel invasion after stimulation with saline, IL-1β and TGF-β1 were evaluated using three primary and three metastatic pancreatic cancer cell lines. Results Extracellular matrix adhesion of control cells varied independently of the metastatic characteristics of the studied cell lines, whereas Matrigel invasion of control cells was partly correlated with the in vivo metastatic potential. IL-1β did not influence extracellular matrix adhesion, whereas it significantly enhanced the invasiveness of three of the six cell lines. TGF-β1 affected the adhesion of one cell line, and exerted contrasting effects on Matrigel invasion of different cell lines. Conclusions IL-1β enhances the invasive capacity of pancreatic cancer cells, whereas TGF-β1 has paradoxical effects on pancreatic cancer cells; this makes it difficult to interfere with TGF-β1 signaling in pancreatic cancer treatment.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 4125-4125
Author(s):  
S. Nakahira ◽  
S. Nakamori ◽  
M. Tsujie ◽  
J. Okami ◽  
I. Takemasa ◽  
...  

4125 Background: Pancreatic cancer is the most lethal of all solid tumors partially because of its chemoresistance. Although a deoxycytidine analogue, gemcitabine, is widely used as a first selected and a single agent for the treatment of this disease despite low response rate, molecular mechanisms of gemcitabine resistance in pancreatic cancer still remain obscure. The purpose of this study is to identify the molecular marker for gemcitabine resistance in human pancreatic cancer. Methods: Gemcitabine resistant variants were established from human pancreatic cancer cell lines, MiaPaCa2. Gene expression changes between parental cells and resistant cells were assessed by an oligonucleotide microarray covering 30,000 human oligonucleotides, and candidate genes were validated by RT-PCR and Western blotting. The association to resistance was validated by RNAi assay. Clinical effects on 18 recurrent pancreatic cancer patients treated by gemcitabine were evaluated using mRNA of specimens resected at the primary operation. Results: The 81-fold gemcitabine resistant variant MiaPaCa2-RG was selected from pancreatic cancer cell line MiaPaCa2. By microarray analysis between parental and resistant MiaPaCa2 cells, 99.6% genes were altered expression of less than 2-fold. Among 43 genes with altered expression of more than 2-fold, the most up-regulated gene in MiaPaCa2-RG cells is ribonucleotide reductase M1 subunit (RRM1) with 4.5-fold up-regulation compared with MiaPaCa2 cells. Transfection with RRM1-specific RNAi suppressed more than 90% of RRM1 mRNA and protein expression both in MiaPaCa2 and MiaPaCa2-RG cells. After RRM1-specific RNAi transfection, gemcitabine chemoresistance of MiaPaCa2-RG was significantly reduced to the same level of MiaPaCa2. The 18 recurrent pancreatic cancer patients were divided into two groups by RRM1 mRNA expression levels. There was a significant association between gemcitabine response and RRM1 expression (p = 0.018). Furthermore, patients with high RRM1 levels had a poor survival times after gemcitabine treatment than those with low RRM1 levels (p = 0.016). Conclusions: RRM1 should be a key molecule in gemcitabine resistance in pancreatic cancer through both in vitro and clinical models. RRM1 should be considered as the predictor of gemcitabine resistance. No significant financial relationships to disclose.


Sign in / Sign up

Export Citation Format

Share Document