INHIBITING THE KERATINOCYTE CELL CYCLE KINASES

• 48h inhibiting mitotic kinases in human skin keratinocytes irreversibly induces terminal differentiation and suppresses clonogenic potential. However,
• 48h inhibiting cell cycle entry kinase cdk2 delays differentiation and confers a higher clonogenic potential.

Further suggesting that epidermal keratinocytes need cell growth to fully differentiate.




 
Colonies of human primary keratinocytes after the treatments indicated.

Double immunofluorescence for Cyclin E (red) and the differentiation

marker involucrin (green), DNA was stained in blue by DAPI  (Upper Panels).

Note that inhibition of mitotic kinases (cdk1, Pololk) renders small, differentiated colonies,

whose cells irreversibly lose their capacity to proliferate.

Bar:100 µm. Freije et al, Oncogene, 2012, Supplementary Data.

   

EPIDERMAL STARS

We investigate the cell cycle and differentiation of skin epidermal cells. Both need to be coordinated as an orchestra to avoid neoplasic development.
In vitro, we study the links governing epidermal homeostasis that protect the skin from cancer.

Primary keratinocytes behave closely resembling the physiology of the skin.
In situ, we study skin cancer.

Our research walks on the edge between molecular developmental cues and human disease.

Primary human keratinocytes expresing a GFP form of a cell cycle regulator (GREEN) and a differentiation keratin (RED).
Skin from the Peadriatic Surgery Department of Valdecilla hospital in Santander.
Cell culture and staining by Laura Ceballos.

  

A SKIN COVER FOR 'CELL CYCLE'

A molecular switch triggers squamous differentiation and endoreplication upon cell cycle hyperactivation.






Gandarillas, Dic. 2012 -COVER- http://www.landesbioscience.com/journals/cc/



WE COVER THE CELL CYCLE

Cell Cycle journal has selected one of our images for the current December 2012 issue cover.
http://www.landesbioscience.com/journals/cc/



Deregulation of the keratinocyte cell cycle induces epidermal differentiation. Human
epidermal keratinocytes overexpressing fluorescent cyclin E (green) and the differentiation marker involucrin (red).
For more information, Gandarillas., pp. 4507–16.
See also Freije et al, 2012, http://www.nature.com/onc/journal/v31/n50/abs/onc201222a.html

 

PROYECTO EUROPEO EN ALERTA (Spanish)-

THE NEW SKIN EPIDERMAL CELL CYCLE IN CELL CYCLE -open access


Cell Cycle. 2012 Oct 31;11(24). [Epub ahead of print]
http://www.landesbioscience.com/journals/cc/article/22529/

Source http://www.ncbi.nlm.nih.gov/pubmed/23114621

The mysterious human epidermal cell cycle, or an oncogene-induced differentiation checkpoint.

Gandarillas A.

Cell Cycle, Stem Cell Fate and Cancer Laboratory; Fundación Marqués de Valdecilla-Instituto de Formación e Investigación Marqués de Valdecilla (IFIMAV); Santander, Spain; Institut National de la Santé et de la Recherche Médicale (INSERM); ADR Languedoc-Roussillon; Montpellier, France.

Abstract

  


Gandarillas, 2012, Cell Cycle

Fifteen years ago, we reported that proto-oncogene MYC promoted differentiation of human epidermal stem cells, a finding that was surprising to the MYC and the skin research communities. MYC was one of the first human oncogenes identified, and it had been strongly associated with proliferation. However, it was later shown that MYC could induce apoptosis under low survival conditions. Currently, the notion that MYC promotes epidermal differentiation is widely accepted, but the cell cycle mechanisms that elicit this function remain unresolved. We have recently reported that keratinocytes respond to cell cycle deregulation and DNA damage by triggering terminal differentiation. This mechanism might constitute a homeostatic protection face to cell cycle insults. Here, I discuss recent and not-so-recent evidence suggesting the existence of a largely unexplored oncogene-induced differentiation response (OID) analogous to oncogene-induced apoptosis (OIA) or senescence (OIS). In addition, I propose a model for the role of the cell cycle in skin homeostasis maintenance and for the dual role of MYC in differentiation.

PMID:

23114621

[PubMed - as supplied by publisher]

NEW WORK FOR PUBLICATION IN CELL CYCLE

Within this View,



The Epidermis maintains tissue structure upon hyperproliferative stimuli



- We propose a model for the coordination between cell multiplication and differentiation in human epidermis that constitutes a novel skin homeostatic mechanism against cell cycle deregulation.

- We propose a model for the dual action of the protooncogene MYC in differentiation.



Soon available online at Cell Cycle

http://www.landesbioscience.com/journals/cc/

and PubMed

http://www.ncbi.nlm.nih.gov/pubmed

 








EUROPE

On October the second, we submitted a scientific proposal to the 7FP of the European Union-HEALTH as coordinators (first stage).

·      This is the first European proposal coordinated by the FMV-IFIMAV.

·      The project links scientific centres, hospitals and Small or Medium Enterprise (SME) from 8 European countries.

·      The main objective is the translation of scientific and technological research into SME and Society.

 

http://europa.eu/index_en.htm



THE EPIGENETIC FACTOR BORIS LOCALISES TO THE NUCLEOLUS IN LIVE CELLS

Live cells expressing GREEN-fluorescent BORIS and RED-fluorescent fibrillarin,
a marker of nucleoli. From Rosa-Garrido et al, PLoS ONE, 2012.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0039371
Video formatting, María Hidalgo.

THE ROMAN PAVEMENT



In vitro cultured keratinocytes from human skin. Skin biopsy from the Marqués de Valdecilla Hospital.



EN ALERTA

NEW WORK ON BORIS AND THE CELL CYCLE

A Cell Cycle Role for the Epigenetic Factor CTCF-L/BORIS

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0039371

Manuel Rosa-Garrido^1,2#, Laura Ceballos^1,2#, Pilar Alonso-Lecue¹, Cristina Abraira², M. Dolores Delgado², Alberto Gandarillas^1,2,3*

1 Cell Cycle, Stem Cell Fate and Cancer Laboratory, Fundación Marqués de Valdecilla-Instituto de Formación e Investigación Marqués de Valdecilla, Santander, Spain, 2 Departamento de Biología Molecular, Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria-Consejo Superior de Investigaciones Científicas, SODERCAN, Santander, Spain, 3 Institut National de la Santé et de la Recherche Médicale, ADR Languedoc-Roussillon, Montpellier, France

Abstract

CTCF is a ubiquitous epigenetic regulator that has been proposed as a master keeper of chromatin organisation. CTCF-like, or BORIS, is thought to antagonise CTCF and has been found in normal testis, ovary and a large variety of tumour cells. The cellular function of BORIS remains intriguing although it might be involved in developmental reprogramming of gene expression patterns. We here unravel the expression of CTCF and BORIS proteins throughout human epidermis. While CTCF is widely distributed within the nucleus, BORIS is confined to the nucleolus and other euchromatin domains. Nascent RNA experiments in primary keratinocytes revealed that endogenous BORIS is present in active transcription sites. Interestingly, BORIS also localises to interphase centrosomes suggesting a role in the cell cycle. Blocking the cell cycle at S phase or mitosis, or causing DNA damage, produced a striking accumulation of BORIS. Consistently, ectopic expression of wild type or GFP- BORIS provoked a higher rate of S phase cells as well as genomic instability by mitosis failure. Furthermore, down-regulation of endogenous BORIS by specific shRNAs inhibited both RNA transcription and cell cycle progression. The results altogether suggest a role for BORIS in coordinating S phase events with mitosis.

PLoS ONE 7(6): e39371. doi:10.1371/journal.pone.0039371

NEW WORK ON PODOPLANIN IN J. AM. AC. DERMATOLOGY

J Am Acad Dermatol. 2012 Apr 19. [Epub ahead of print]

D2-40 immunohistochemical overexpression in cutaneous squamous cell carcinomas: A marker of metastatic risk.

Toll A, Gimeno-Beltrán J, Ferrandiz-Pulido C, Masferrer E, Yébenes M, Jucglà A, Abal L, Martí RM, Sanmartín O, Baró T, Casado B, Gandarillas A, Barranco C, Costa I, Mojal S, García-Patos V, Pujol RM.

Source

Department of Dermatology, Hospital del Mar, Parc de Salut Mar, Barcelona, Spain.

Abstract

BACKGROUND:

Approximately 4% of cutaneous squamous cell carcinomas (cSCCs) develop lymphatic metastases. The value of lymphatic endothelial markers to enhance the detection of lymphatic tumor invasion in cSCC has not been assessed previously.

OBJECTIVE:

We sought to evaluate the use of the antibody D2-40, a podoplanin immunohistochemical marker, to identify tumor lymph vessel invasion in cSCC and to assess its expression in tumor cells.

METHODS:

A skin carcinoma section

This was a retrospective case-control study. A series of 101 cSCC, including 51 cases that developed lymphatic metastatic spread (metastasizing cSCC [MSCC]) and 50 cases that resolved definitely after surgical excision (non-MSCC) were included in the study. Lymph vessel invasion using D2-40 was evaluated on all primary biopsy specimens. The percentage of tumor cells showing D2-40 positivity and intensity scoring were recorded. All the immunohistochemical findings were correlated with the clinicopathological features.

RESULTS:

Lymph vessel invasion was observed in 8% of non-MSCCs and in 25.5% of MSCCs (P = .031). D2-40 expression was significantly increased, both in intensity (odds ratio 4.42 for intensity ++/+++) and in area (odds ratio 2.29 for area >10%), in MSCC when compared with non-MSCC. Interestingly, almost half (49%) of the MSCC had moderate to intense D2-40 positivity compared with 16% of non-MSCC. D2-40 immunohistochemical expression was increased in tumors with an infiltrative pattern of extension. In the multivariate analysis, histologically poorly differentiated tumors, recurrent lesions, and cSCC showing D2-40 overexpression (in intensity) were significantly associated with lymphatic metastases development (odds ratios 15.67, 14.72, and 6.07, respectively).

LIMITATIONS:

This was a retrospective study.

CONCLUSION:

The expression of podoplanin associates with high metastatic risk in cSCC.

Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

3D KERATINOCYTE CULTURES

3D reconstruction of confocal microscopy analyses of an in vitro colony of human primary stratifying keratinocytes. Immunofluoro-staining for the cell cycle regulator Cyclin E (green) and the differentiation marker involucrin (red); nuclear DNA counter-stained by Dapi (blue). Note that Cyclin E accumulates as cells stratify (see also Zanet et al, 2010 and Freije et al, 2012). Labelling and video by María Hidalgo.

NEW WORK IN STEM CELLS

Stem Cells. 2012 Mar 21. doi: 10.1002/stem.1090. [Epub ahead of print]

The Proto-Oncogene Myc is Essential for Mammary Stem Cell Function.

Moumen M, Chiche A, Deugnier MA, Petit V, Gandarillas A, Glukhova MA, Faraldo MM.

Source

Institut Curie, Centre de Recherche, Paris, F-75248 France; CNRS, UMR144, Paris, F-75248, France.

Abstract

The mammary epithelium comprises two major cell lineages: basal and luminal. Basal cells (BCs) isolated from the mammary epithelium and transplanted into the mouse mammary fat pad cleared from the endogenous epithelium regenerate the mammary gland, strongly suggesting that the basal epithelial compartment harbors a long-lived cell population with multipotent stem cell potential. The luminal cell layer is devoid of the regenerative potential but it contains cells with clonogenic capacity, the luminal progenitors. Mammary BCs and luminal progenitors express high levels of the transcription factor Myc. Here we show that deletion of Myc from mammary basal epithelial cells led to impaired stem cell self-renewal as evaluated by limiting dilution and serial transplantation assays. Luminal progenitor population was significantly diminished in mutant epithelium suggesting control by the basal cell layer. Colony formation assay performed with isolated basal cells showed that clonogenic capacity was abolished by Myc deletion. Moreover, transplanted BCs depleted of Myc failed to produce epithelial outgrowths. Stimulation with ovarian hormones estrogen (E) and progesterone (P) partially rescued the repopulation capacity of Myc-depleted BCs, however, the Myc-deficient mammary epithelium developed in response to E/P treatment lacked stem and progenitor cells. This study provides the first evidence that in the mammary gland, Myc has an essential non-redundant function in the maintenance of the self-renewing multipotent stem cell population responsible for the regenerative capacity of the mammary epithelium and is required downstream from ovarian hormones, for the control of mammary stem and progenitor cell functions.

Copyright © 2012 AlphaMed Press.
PMID:
22438054
[PubMed - as supplied by publisher]