Drug Discovery
  Molecular Analysis
  Organic and Organometallic Chemistry
  Medicinal Chemistry
  Structural Biology & Chemistry
  Molecular Endocrinology
  Signal Mediated Gene Expression
  Molecular & Cellular Ageing
  Biomedical Applications
  Holistic Approaches in Health
  Chemical Carcinogenesis and Genetic Toxicology
  Metabolic Engineering-Bioinformatics
  Enzyme and Synthetic Biotechnology
  Biomimetics & Nanobiotechnology


Signal Mediated Gene Expression


Alexander Pintzas, PhD, Researcher A'

Research Team
Vivian Kosmidou, MSc, Research Assistant
Angelo Ferraro, PhD, Senior Post-doctoral Fellow
Philippos Perimenis, PhD, Post-doctoral Fellow
Margarita Vlassi, MSc, Research Fellow
Maria Goulielmaki, MSc, Research Fellow
Evangelos Koustas, BSc, Research Fellow



Research objectives – Major Achievements

The Laboratory activities are focusing on the interplay between oncogenic and apoptotic signals and its exploitation towards uncovering sensitisation pathways to targeted cancer therapeutics. The analysis of genetic and epigenetic events as well as global gene expression in physiological as compared to neoplastic cells. is the other focus of the lab.

a) Sensitisation to cancer therapeutic molecules and their rational combinations
The interplay between oncogenic RAS with apoptotic signals induced by the cytokine TRAIL, a novel potent cancer therapeutic agent has been analysed. TRAIL induced apoptosis in mouse xenographs of primary colon tumour cells partially due to upregulation of DR5  (Oikonomou et al. Br. J. Cancer, 2007). Oncogenic forms of RAS sensitise human colon cells to TRAIL induced apoptosis by upregulating TRAIL receptors DR4 and DR5 through a MEK-dependent pathway (Drosopoulos et al. J. Biol. Chem. 2005, reviewed in:  Oikonomou and Pintzas, Biofactors, 2013). Existence of KRAS and BRAF mutations in colorectal tumours is associated with DR overexpression, which indicates that these patients may potentially respond to TRAIL treatment (Oikonomou et al., Int J Cancer, 2009). Rational combination studies of TRAIL with small molecule inhibitors of activated kinase pathways have been performed. Interestingly, BRAF and PI3K inhibitors can synergise with TRAIL to sensitise tumour cells to apoptosis (Oikonomou et al., PLoS ONE, 2011). In addition, polyphenol quercetin has been shown to synergise with TRAIL on causing apoptotic death by inducing accumulation of TRAIL receptors in lipid rafts (Psahoulia et al., Mol. Cancer. Ther, 2007). The findings of an EU-funded consortium on the effect of kinase inhibitors on tumours and their combinatorial effect with TRAIL have been described (Pintzas et al., Cancer Biology and Therapy, 2012)
One other goal was the development of exploitable in vitro chemoprevention cell systems, based on the home made inducible oncogene expression systems In the same study, we have shown that the polyphenol quercetin induced autophagy in Ha-Ras transformed cells (Psahoulia et al. Carcinogenesis, 2007). 
Currently, novel specific potential PI3K inhibitors are being screened in a drug discovery project in the frame of the POM programme. Also, new efficient anti-cancer rational combinations of TRAIL with apoptosis inhibitors are being developed in the frame of THERA-CAN programme. In parallel, other novel anti-tumour kinase inhibitors will be developed shortly in the frame of STHENOS project.

Tumour heterogeneity revealed by detection of K-RAs mutations.

Kosmidou et al. Human Mutation (2013).doi: 10.1002/humu.22496

b) Oncogenic pathway analysis in human colorectal carcinogenesis
The remarkable heterogeneity in colorectal cancer has been revealed by the detection of different KRAS mutations in different tumour parts using pyrosequencing analysis (Kosmidou et al., Human Mutation, 2014). On the other hand, analysis of gene expression profile during tumour progression in colon cancer cell lines has been performed (Roberts et al. Int. J. Cancer, 2006). Candidate genes to be involved in colon tumour progression have been identified by microarray analysis and their role is currently being validated. BRAFV600E target gene analysis (Joyce et al. Current Cancer Drug Targets, 2012) has being performed using the Illumina microarray platform. On the other hand, the comparative effect of KRASV12 vs BRAFV600E has being analysed (Oikonomou, Makrodouli, et al., Neoplasia, 2009; Makrodouli et al., Mol. Cancer, 2012). The importance of mutant RAS and PIK3CA heterogeneity in currently examined, also in terms of its therapeutic implications.

c) Genetic-epigenetic mechanisms of Epithelial-Mesenchymal Transition (EMT) and metastasis in cancer
An epigenetic regulatory network involving miR-21/ITGB4 and PDCD4 has been identified and shown to be important as predictor of metastasis in colorectal cancer. Moreover, we have established a cell model of highly metastatic Epithelial to Mesenchymal Transition (EMT) phenotype in colon adenoma cells by Ha-RASV12 oncogene. Whole genome analysis has been performed and a signature of EMT has been revealed (Joyce et al., Clin. Exp. Metastasis, 2009). The role of EMT in resistance of cancer cells to therapies has been also reviewed (Voulgari et al., BBA Reviews on Cancer, 2009). Regulation of EMT associated genes by AP-1 and TFIID transcription factors has been shown (Andreolas et al., Int. J. Cancer, 2008, Kalogeropoulou et al., Mol. Cancer Res., 2010). On the other hand, selected histone modifications and modifiers associated with EMT have been identified (Mazon-Pelaez et al., Int J Biochem Cell Biol., 2010) and an important role of EZH2 histone methyltransferase in regulating EMT and anoikis has been revealed (Ferraro et al., Int J Biochem Cell Biol., 2013). The significance of epigenetic markers towards their exploitation in clinical practice is currently examined.


Awarded Research Grants (selected, 2005-2013): > 3,000 kEuros

  1. 2013-2015:“STHENOS”, Targeted therapeutic approaches against degenerative diseases, with special focus on cancer and ageing. National Strategic Reference Framework, Action “Developmental Projects of Research Organisations- Kripis”. Funding for the Institute: 1500 kEuros Funding for the lab: 30 kEuros (co-ordinator).
  2. 2012-2015: “THERACAN”,  Exploiting molecular pathways of apoptotic cell death for the rational design of therapeutic strategies for colon cancer. National Strategic Reference Framework, Action “Co-operation II”. Funding for the lab: 200 kEuros
  3. 2009-2013 : “EpiDiaCan”, Development of sensitive methodologies for exploitation of early epigenetic marker diagnosis in major types of cancer. 7FP EU- Cooperation” –Theme "Health”. Total funding 2.843 kEuros, for the lab 504 kEuros (Co-ordinator)
  4. 2010-2014: “POM”. PIK3CA Oncogenic Mutations in Breast and Colon Cancers: Development of Targeted Anticancer Drugs and Diagnostics. National  Strategic Reference Framework, Action “Co-operation”. Funding for NHRF: 330kEuros, for the lab: 130 kEuros
  5. 2006-2010 : “Oncodeath” Resistant determinants and sensitisation of solid tumor cells to death receptor related therapies: combination of TRAIL with other therapeutic molecules. EU-Combating Cancer Programme. Total funding 2.345 kEuros , for the lab: 345 kEuros (Co-ordinator)
  6. 2006-2009: Functional oncogenomics: a powerful tool towards diagnosis and treatment of human colorectal cancer. Greek Research Network PENED. Funding 235 kEuros (Co-ordinator)
  7. 2004-2008: “Macromolecular assemblies involved in regulated gene expression: structural/functional characteristics, interplay and novel functions”, EU Transfer of Knowledge (TOK) Research Programme, funding for the lab: 250 kEuros
  8. 2004-2008: “TAF-Chromatin” EU Research Training Network (RTN) Programme. Participation of 7 labs from 6 countries. Funding for the lab: 370 kEuros.
  9. 2004-2007: “Transcription complex dynamics controlling specific gene expression programs” EU- Fundamental Genomics Programme. funding for the lab: 450 kEuros
  10. 2004-2006: “Molecular mechanisms of tumour invasion and metastasis”, Research cooperation programme between Greece and USA. Funding for the lab: 60 kEuros
  11. 2003-2006:  “In vivo and in silico analysis of gene expression induced by Ras oncogene in cancer” , Greek Research Network PENED. Funding 140 kEuros (co-ordinator)
  12. 2002-2005: “Regulation of transcription and mRNA processing by oncogenic signals”, EU-IHP Research Programme. Funding: 228 kEuros  (co-ordinator)


Selected publications (2005-2013: I.F >5)

1. Ferraro, A., Kontos, C., Boni, T., Bantounas, I., Siakouli, D., Kosmidou, V., Vlassi, M., Spyridakis, Y., Tsipras, I., Zografos, G., and Pintzas, A. (2014). Epigenetic regulation of miR-21 in colorectal cancer: ITGB4 as a novel miR-21 target and a three-gene network (miR-21-ITGB4-PCDC4) as predictor of metastatic tumor potential. Epigenetics 9, 129-141.

2. Kosmidou, V., Oikonomou, E., Vlassi, M., Avlonitis, S., Katseli, A., Tsipras, I., Moutzoukou, D., Kontogeorgos, G., Zografos, G. and Pintzas, A. (2013). Intratumor heterogeneity revealed by KRAS, BRAF and PIK3CA pyrosequencing:  KRAS double mutations and mutation profile differences between tumor center and periphery. Human Mutation. In press. doi: 10.1002/humu.22496.

3. Ferraro, A., Mourtzoukou, D., Kosmidou, V., Avlonitis, S., Kontogeorgos, G., Zografos, G., and Pintzas, A. (2013). EZH2 is regulated by ERK/AKT and targets Integrin α2 gene to control Epithelial-Mesenchymal Transition and anoikis in colon cancer cells. Int J Biochem Cell Biol, 45, 243-254.

4. Makrodouli, E., Oikonomou, E., Koc, M., Andera, L., Sasazuki, T., Shirasawa, S., and Pintzas, A. (2011). BRAF and RAS oncogenes regulate  Rho GTPase pathways to induce migration and invasion properties in human colon cancer cells: a comparative study. Mol. Cancer 10, 118.  (Highly accessed article in BioMed Central)

5. Mazón Peláez, I., Kalogeropoulou, M., Ferraro, A., Voulgari, A., Pankotai, T., Boros, I., and  Pintzas, A. (2010). Oncogenic RAS alters the global and gene specific Histone modification pattern during Epithelial-Mesenchymal Transition in colorectal carcinoma cells. Int. J. Biochem. Cell Biol. 42, 911–920  

6. Kalogeropoulou M., Voulgari A., Kostourou, V., Sandaltzopoulos, R., Dikstein, R., Davidson, I., Tora, L. and Pintzas, A.(2010). TAF4b and Jun/AP-1 collaborate to regulate expression of Integrin α6 and cancer cell migration properties.Mol. Cancer Res. 8, 554-568.

7. Voulgari A. and Pintzas, A. (2009). Epithelial-Mesenchymal Transition in cancer metastasis: mechanisms, markers and strategies to overcome drug resistance in the clinic. BBA Reviews on Cancer 1796, 75-90. (5th most cited Journal’s article)

8. Oikonomou, E., Kosmidou, V., Katseli, A., Kothonidis, K., Mourtzoukou, D.,   Kontogeorgos, G., Andera, L., Zografos, G., and Pintzas, A. (2009). TRAIL Receptor Upregulation Correlates to KRAS/ BRAF Mutations in Human Colon Cancer Tumours and Respective Normal Tissue. Int. J. Cancer 125, 2127-2135.

9. Oikonomou E., Makrodouli E.,  Evagelidou, M., Joyce T., Probert, L. and  Pintzas A. (2009). BRAFV600E efficient transformation and induction of MSI versus KRASG12V induction of senescence markers in human colon cancer cells. Neoplasia 11, 1116-1131.

10. Andreolas C., Kalogeropoulou, M., Voulgari, A. and Pintzas, A. (2008). Oncogenic Ha-RAS enhances Vimentin expression through FRA-1 to induce Epithelial Mesenchymal Transition in human colon carcinoma cells. Int. J. Cancer  122, 1745–1756.

11. Voulgari, A., Voskou, S., Tora, L., Davidson, I. Sasazuki T., Shirasawa, S., and Pintzas, A. (2008). TAF12 is important for Ras-induced transformation properties of colorectal cancer cells. Mol. Cancer Res. 6, 1071-1083.

12. Psahoulia, F.H., Moumtzi , S., Roberts, M.L., Sasazuki T., Shirasawa S. , and Pintzas, A. (2007). Quercetin mediates preferential degradation of oncogenic Ras and causes autophagy in Ha-RAS-transformed human colon cells. Carcinogenesis 28, 1021-1031.

13. Oikonomou, E., Kothonidis, K., Taoufik, E., Probert, L., Zografos, G., Nasioulas, G., Andera, L., and  Pintzas, A. (2007). Newly Established Tumourigenic Primary Human Colon Cancer Cell Lines are Sensitive to TRAIL Induced Apoptosis in vitro and in vivo. Br. J. Cancer  97, 73 – 84.
14. Psahoulia, F. H., Drosopoulos K. G., Doubravska, L., Andera, L. and Pintzas, A. (2007). Quercetin enhances TRAIL-mediated apoptosis in colon cancer cells by inducing the accumulation of death receptors in lipid rafts. Mol. Cancer. Ther  6, 2591-2599.

15. Roberts, M., Drosopoulos, K., Vasileiou, G., Stricker, M., Taoufik E., Maercker, C., Guialis, A., Alexis, MN. and Pintzas, A. (2006). Microarray analysis of the differential transformation mediated by kirsten and harvey ras oncogenes in a human colon adenocarcinoma cell line. Int. J. Cancer 118, 616–627.

15. Drosopoulos, K. Roberts , M., Cermak, L., Sasazuki , T., Shirasawa, S.,  Andera L. and  Pintzas, A. (2005). Oncogenic Ras transformation sensitizes human colon cancer cells to TRAIL induced apoptosis by upregulating DR4 and DR5 receptors through a MEK dependent pathway. J. Biol. Chem. 280, 22856-22867.


Dr Alexandros Pintzas , Researcher A’
Laboratory of Signal Mediated Gene Expression
Institute of Biology, Medicinal Chemistry and Biotechnology
National Hellenic Research Foundation (N.H.R.F.)
48 Vas. Constantinou Ave., 116 35 Athens, Greece
Tel: 30 210 7273753, 30 210 7273745
Fax: 30 210 7273677, e-mail:





Development of sensitive methodologies for exploitation of early epigenetic marker diagnosis in major types of cancer
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Sensitisation of solid tumour cells to death receptor related therapies
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Marie Curie Research Training Network TAF-Chromatin


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