open access

Vol 56, No 1 (2018)
Original paper
Submitted: 2017-08-22
Accepted: 2018-02-28
Published online: 2018-03-09
Get Citation

Epac1 is involved in cell cycle progression in lung cancer through PKC and Cx43 regulation

Qian Sun1, Dai Wang1, Ganghao Ai2, Longben Tian1, Long Zhao1, Renzhen Chen1, Kai Wang1, Dongbei Guo1, Youliang Yao1, Wenzhi Liu2, XIangyu Kong2, Xiaoxuan Chen1, Yongxing Zhang1
DOI: 10.5603/FHC.a2018.0004
·
Pubmed: 29528086
·
Folia Histochem Cytobiol 2018;56(1):21-26.
Affiliations
  1. State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen Fujian,361102, PR China
  2. Department of Gastrointestinal Surgery, Affiliated Zhongshan Hospital of Dalian University, Dalian 116001, Liaoning, PR China

open access

Vol 56, No 1 (2018)
ORIGINAL PAPERS
Submitted: 2017-08-22
Accepted: 2018-02-28
Published online: 2018-03-09

Abstract

Introduction. The exchange protein directly activated by cAMP (Epac1), a downstream target of the second messenger cAMP, modulates multiple biological effects of cAMP, alone or in cooperation with protein kinase A (PKC). Epac1 is necessary for promoting protein kinase C (PKC) translocation and activation. The aim of the study was to assess the intensity of Epac1 and protein kinase C (PKC) immunoreactivity in lung cancer and para-carcinoma tissues, and their associations with clinical-pathological indexes. Correlations between the immunoreactivity of Epac1, PKC, A-kinase anchor protein 95 (AKAP95) and connexin43 (Cx43) were also examined.

Material and methods. Epac1, Cx43 (46 cases) and PKC, AKAP95 (45 cases) immunoexpression levels were determined in tissue samples of lung cancer and in 12 samples of neighboring para-carcinoma specimens by the PV-9000 Two-step immunohistochemical technique.

Results. The percentage of Epac1 positive samples was significantly lower in lung cancer tissue than in neighboring para-carcinoma specimens (37% vs. 83.3%, p < 0.05); the difference in PKC immunoreactivity was not significant (64.4% vs. 91.7%). Epac1 expression was associated with the degree of malignancy and lymph node metastasis (P < 0.05), but not with histological type (P > 0.05), whereas PKC expression was not related to these parameters. Interestingly, Epac1 expression was correlated with PKC and Cx43 expression. Moreover, PKC expression was correlated with AKAP95 expression.

Conclusion. Normal Epac1 expression may suppress lung cancer occurrence and metastasis, and its downregulation is involved in cell cycle progression in lung cancer through PKC and Cx43 regulation.  

Abstract

Introduction. The exchange protein directly activated by cAMP (Epac1), a downstream target of the second messenger cAMP, modulates multiple biological effects of cAMP, alone or in cooperation with protein kinase A (PKC). Epac1 is necessary for promoting protein kinase C (PKC) translocation and activation. The aim of the study was to assess the intensity of Epac1 and protein kinase C (PKC) immunoreactivity in lung cancer and para-carcinoma tissues, and their associations with clinical-pathological indexes. Correlations between the immunoreactivity of Epac1, PKC, A-kinase anchor protein 95 (AKAP95) and connexin43 (Cx43) were also examined.

Material and methods. Epac1, Cx43 (46 cases) and PKC, AKAP95 (45 cases) immunoexpression levels were determined in tissue samples of lung cancer and in 12 samples of neighboring para-carcinoma specimens by the PV-9000 Two-step immunohistochemical technique.

Results. The percentage of Epac1 positive samples was significantly lower in lung cancer tissue than in neighboring para-carcinoma specimens (37% vs. 83.3%, p < 0.05); the difference in PKC immunoreactivity was not significant (64.4% vs. 91.7%). Epac1 expression was associated with the degree of malignancy and lymph node metastasis (P < 0.05), but not with histological type (P > 0.05), whereas PKC expression was not related to these parameters. Interestingly, Epac1 expression was correlated with PKC and Cx43 expression. Moreover, PKC expression was correlated with AKAP95 expression.

Conclusion. Normal Epac1 expression may suppress lung cancer occurrence and metastasis, and its downregulation is involved in cell cycle progression in lung cancer through PKC and Cx43 regulation.  

Get Citation

Keywords

lung cancer; Epac1; PKC; AKAP95; Cx43; IHC

About this article
Title

Epac1 is involved in cell cycle progression in lung cancer through PKC and Cx43 regulation

Journal

Folia Histochemica et Cytobiologica

Issue

Vol 56, No 1 (2018)

Article type

Original paper

Pages

21-26

Published online

2018-03-09

DOI

10.5603/FHC.a2018.0004

Pubmed

29528086

Bibliographic record

Folia Histochem Cytobiol 2018;56(1):21-26.

Keywords

lung cancer
Epac1
PKC
AKAP95
Cx43
IHC

Authors

Qian Sun
Dai Wang
Ganghao Ai
Longben Tian
Long Zhao
Renzhen Chen
Kai Wang
Dongbei Guo
Youliang Yao
Wenzhi Liu
XIangyu Kong
Xiaoxuan Chen
Yongxing Zhang

References (30)
  1. Hewer RC, Sala-Newby GB, Wu YJ, et al. PKA and Epac synergistically inhibit smooth muscle cell proliferation. J Mol Cell Cardiol. 2011; 50(1): 87–98.
  2. Hucho TB. Epac Mediates a cAMP-to-PKC Signaling in Inflammatory Pain: An Isolectin B4(+) Neuron-Specific Mechanism. Journal of Neuroscience. 2005; 25(26): 6119–6126.
  3. Diviani D, Dodge-Kafka KL, Li J, et al. A-kinase anchoring proteins: scaffolding proteins in the heart. Am J Physiol Heart Circ Physiol. 2011; 301(5): H1742–H1753.
  4. Tittarelli A, Guerrero I, Tempio F, et al. Overexpression of connexin 43 reduces melanoma proliferative and metastatic capacity. Br J Cancer. 2015; 113(2): 259–267.
  5. Cronier L, Crespin S, Strale PO, et al. Gap junctions and cancer: new functions for an old story. Antioxid Redox Signal. 2009; 11(2): 323–338.
  6. Benko G, Spajić B, Demirović A, et al. Prognostic value of connexin43 expression in patients with clinically localized prostate cancer. Prostate Cancer Prostatic Dis. 2011; 14(1): 90–95.
  7. Chen X, Kong X, Zhuang W, et al. Dynamic changes in protein interaction between AKAP95 and Cx43 during cell cycle progression of A549 cells. Sci Rep. 2016; 6: 21224.
  8. Somekawa S, Fukuhara S, Nakaoka Y, et al. Enhanced functional gap junction neoformation by protein kinase A-dependent and Epac-dependent signals downstream of cAMP in cardiac myocytes. Circ Res. 2005; 97(7): 655–662.
  9. YiDe Chen, XiaoXuan Chen, LiNa Chen, FengChao Liang, Ye Ding, XiuYi Yu, MaoQiang Xue, YongXing Zhang. Clinical significance of AKAP95 and cyclinE2 expression in lung cancer tissues and its association with Cx43. Chinese Journal of Industrial Hygiene and Occupational Diseases. 2012; 30: 725–729.
  10. Dao KK, Teigen K, Kopperud R, et al. Epac1 and cAMP-dependent protein kinase holoenzyme have similar cAMP affinity, but their cAMP domains have distinct structural features and cyclic nucleotide recognition. J Biol Chem. 2006; 281(30): 21500–21511.
  11. Yokoyama U, Patel HH, Lai NC, et al. The cyclic AMP effector Epac integrates pro- and anti-fibrotic signals. Proc Natl Acad Sci U S A. 2008; 105(17): 6386–6391.
  12. Chrzanowska-Wodnicka M, Kraus AE, Gale D, et al. Defective angiogenesis, endothelial migration, proliferation, and MAPK signaling in Rap1b-deficient mice. Blood. 2008; 111(5): 2647–2656.
  13. Zieba BJ, Artamonov MV, Jin Li, et al. The cAMP-responsive Rap1 guanine nucleotide exchange factor, Epac, induces smooth muscle relaxation by down-regulation of RhoA activity. J Biol Chem. 2011; 286(19): 16681–16692.
  14. Hewer RC, Sala-Newby GB, Wu YJ, et al. PKA and Epac synergistically inhibit smooth muscle cell proliferation. J Mol Cell Cardiol. 2011; 50(1): 87–98.
  15. Grandoch M, Rose A, ter Braak M, et al. Epac inhibits migration and proliferation of human prostate carcinoma cells. Br J Cancer. 2009; 101(12): 2038–2042.
  16. Misra UK, Pizzo SV. Epac1-induced cellular proliferation in prostate cancer cells is mediated by B-Raf/ERK and mTOR signaling cascades. J Cell Biochem. 2009; 108(4): 998–1011.
  17. Almahariq M, Tsalkova T, Mei FC, et al. A novel EPAC-specific inhibitor suppresses pancreatic cancer cell migration and invasion. Mol Pharmacol. 2013; 83(1): 122–128.
  18. Sirnes S, Kjenseth A, Leithe E, et al. Interplay between PKC and the MAP kinase pathway in Connexin43 phosphorylation and inhibition of gap junction intercellular communication. Biochem Biophys Res Commun. 2009; 382(1): 41–45.
  19. Antal CE, Hudson AM, Kang E, et al. Cancer-associated protein kinase C mutations reveal kinase's role as tumor suppressor. Cell. 2015; 160(3): 489–502.
  20. Zhang LL, Cao FF, Wang Y, et al. The protein kinase C (PKC) inhibitors combined with chemotherapy in the treatment of advanced non-small cell lung cancer: meta-analysis of randomized controlled trials. Clin Transl Oncol. 2015; 17(5): 371–377.
  21. Craven P, DeRubertis F. Loss of protein kinase C δ isozyme immunoreactivity in human adenocarcinomas. Digestive Diseases and Sciences. 1994; 39(3): 481–489.
  22. Bos JL. Epac proteins: multi-purpose cAMP targets. Trends Biochem Sci. 2006; 31(12): 680–686.
  23. Birukova AA, Zagranichnaya T, Fu P, et al. Prostaglandins PGE(2) and PGI(2) promote endothelial barrier enhancement via PKA- and Epac1/Rap1-dependent Rac activation. Exp Cell Res. 2007; 313(11): 2504–2520.
  24. Doble BW, Dang X, Ping P, et al. Phosphorylation of serine 262 in the gap junction protein connexin-43 regulates DNA synthesis in cell-cell contact forming cardiomyocytes. J Cell Sci. 2004; 117(Pt 3): 507–514.
  25. Britz-Cunningham SH, Shah MM, Zuppan CW, et al. Mutations of the Connexin43 gap-junction gene in patients with heart malformations and defects of laterality. N Engl J Med. 1995; 332(20): 1323–1329.
  26. Sáez JC, Nairn AC, Czernik AJ, et al. Phosphorylation of connexin43 and the regulation of neonatal rat cardiac myocyte gap junctions. J Mol Cell Cardiol. 1997; 29(8): 2131–2145.
  27. Zhao X, Tang X, Ma T, et al. Levonorgestrel Inhibits Human Endometrial Cell Proliferation through the Upregulation of Gap Junctional Intercellular Communication via the Nuclear Translocation of Ser255 Phosphorylated Cx43. Biomed Res Int. 2015; 2015: 758684.
  28. Duquesnes N, Derangeon M, Métrich M, et al. Epac stimulation induces rapid increases in connexin43 phosphorylation and function without preconditioning effect. Pflugers Arch. 2010; 460(4): 731–741.
  29. Mostafavi H, Khaksarian M, Joghataei MT, et al. Selective β2 adrenergic agonist increases Cx43 and miR-451 expression via cAMP-Epac. Mol Med Rep. 2014; 9(6): 2405–2410.
  30. Wong W, Scott JD. AKAP signalling complexes: focal points in space and time. Nat Rev Mol Cell Biol. 2004; 5(12): 959–970.

Regulations

Important: This website uses cookies. More >>

The cookies allow us to identify your computer and find out details about your last visit. They remembering whether you've visited the site before, so that you remain logged in - or to help us work out how many new website visitors we get each month. Most internet browsers accept cookies automatically, but you can change the settings of your browser to erase cookies or prevent automatic acceptance if you prefer.

By "Via Medica sp. z o.o." sp.k., ul. Świętokrzyska 73, 80–180 Gdańsk

tel.:+48 58 320 94 94, faks:+48 58 320 94 60, e-mail:  viamedica@viamedica.pl