MOLECULAR ONCOLOGY GROUP

Education and Training

  • M.Sc. in Molecular Biology, University of Torino, Italy
  • Ph.D. in Cell Biology, University of Rouen, France
  • Post-Doctoral Fellow, Department of Oncological Sciences, Mount Sinai School of Medicine, New York, USA (Stuart Aaronson's lab)
  • Habilitation à diriger des recherche (HDR)

Contact Information

sp`n style="font-size: 10.0pt;" lang="EN-US">Inserm U1239 – DC2N
CURIB Building
2nd floor, room 241
25, rue  Tesnière
76821 Mont-Saint-Aignan
Telephone: +33(0)235 14 6640
Fax: +33(0)235 14 6946
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.  

 

Research Areas: cell signaling in cancer, targeted therapy, drug resistance, tumor heterogeneity

 

Research

 

Our group focuses on the molecular mechanisms and the biological implications of signaling pathway activation in cancer. The evolution of multicellular organisms has involved the development of intercellular communication required for processes such as embryonic development, tissue differentiation, and systemic responses to wounds and infections. These complex signaling networks are in large part mediated by growth factors, cytokines and hormones. In normal conditions, such factors can influence cell proliferation in positive or negative ways, as well as induce a series of differentiated responses in appropriate target cells. Aberrant activation of signaling pathways through different mechanisms contributes to the development and progression of most if not all human cancers.

 

Fig. 1. The CRISPR-barcoding approach

CRISPR-barcoding: a new tool for functional analysis of oncogenic driver mutations in a context of intratumor heterogeneity.

We recently used CRISPR/Cas9 technology to insert a potentially functional modification in the sequence of a gene of interest, coupled to a series of silent point mutations, serving as a genetic label for cell tracing. Because of HDR low efficiency, the modified allele can be introduced only in a small fraction of cells, thus mimicking the emergence of new mutant clones within a cancer mass population. In parallel, a second barcode, consisting of different silent mutations, was used as an internal control for possible CRISPR off-target cleavage. After exposing the cells to a given selective condition, the effects of the mutation of interest can be analyzed by measuring the proportion of each barcode in genomic DNA by real-time quantitative PCR or deep sequencing (Fig. 1). We have applied this strategy to manipulate the endogenous sequence of different oncogenes and tumor suppressors, and we assessed the effects of such modifications on signaling pathway activation, cell growth and invasion, or resistance to chemotherapy, both in vitro and in vivo. Through insertion of a degenerate sequence at a specific genome location, we also labeled several thousand different clones within a mass population of cancer cells to investigate their fate upon inoculation in immunodeficient mice or in the presence of a therapeutic agent, thus demonstrating that CRISPR-barcoding can represent a convenient alternative strategy of randomly integrating lentiviral libraries to trace intratumor heterogeneity (Guernet et al., Mol. Cell). By overcoming the limitations associated with the low efficiency and potential off-target effects of DNA editing, we established a novel approach to recapitulate genetic heterogeneity in virtually all types of cancer cells, which can be easily implemented in functional studies to investigate the effects of a specific genetic modification.

CRISPR-barcoding modeling of non-small cell lung cancer resistance to EGFR inhibitors.

CRISPR-barcoding can be used to experimentally recapitulate cancer evolution through the emergence of subclonal mutations of interest, which can display an improved fitness within the tumor and its microenvironment and whose effects can be monitored in a dynamic manner. A major clinical implication of the complex genetic diversity within individual tumors is the extraordinary capacity of cancer cells to evade therapy. As a paradigm model, non-small-cell lung cancers (NSCLCs) containing EGFR activating mutations generally show a remarkable response to EGFR inhibitors (EGFRi), but almost invariably the tumors relapse, as a result of the emergence of a population of resistant cells. The most common mechanisms responsible for EGFRi resistance include secondary/tertiary EGFR mutations or downstream re-activation of EGFR signaling. We used CRISPR-barcoding in PC9 cells derived from human NSCLC to model the most common mechanism of resistance to EGFRi, the T790M “gatekeeper” mutation in the catalytic domain of this receptor. Consistent with the acquired resistance of the CRISPR/Cas9-modified cells, treatment with the EGFRi gefitinib induced a rapid and dose-dependent enrichment of the EGFR-T790M barcoded cells (Fig. 2). The fact that different mechanisms of resistance can coexist within a tumor or in metastases from the same patient suggests that multiple resistant clones may be present before the onset of therapy. To recapitulate this type of genetic heterogeneity, we used a similar approach to co-introduce in the same PC9 cell culture three mutations potentially capable of conferring resistance to EGFRi, i.e. EGFR-T790M, KRAS-G12D and EML4-ALK (Fig. 3). This type of multiplex model is particularly suited to test the efficacy of combined therapies aimed at preventing or delaying the emergence of resistant cells. Using this model, we recently performed a screen for small molecules potentially capable of inhibiting NSCLC resistance to EGFRi. Through this strategy, we have identified a small molecule capable of preventing amplification of resistant clones in the presence of EGFRi through a novel mechanism.

Fig. 2. CRISPR-barcoding modeling of NSCLC resistance to EGFRi. (A) Incorporation of EGFR-T790M and EGFR-T790T (control) barcodes in NSCLC cells. (C) PC9 cells containing the EGFR barcodes were treated in the presence or the absence of gefitinib (10 nM, arrow), and qPCR was performed from genomic DNA (gDNA) (D) PC9 cells containing the EGFR-T790M and EGFR-T790T barcodes were treated for four days with the indicated concentrations of gefitinib.

Fig. 3. Multiplex Model for NSCLC Resistance to EGFR Inhibition.

The specific aims of our work are:

(1) further characterize the effects of the identified compound, both in vitro and in vivo,

(2) investigate the contribution of intratumor heterogeneity to NSCLC drug resistance

(3) devise new combination treatments to eradicate resistant cells

 

 Selected Publications

 

Guernet A. and Grumolato L. (2017) CRISPR/Cas9 editing of the genome for cancer modeling. Methods 121-122:130-137

 

Grumolato L. and Aaronson S.A. (2017) Positive Mediators of Cell Proliferation in Neoplasia:  Growth Factors and Receptors. In: Coleman W.B. and Tsongalis G.J. The Molecular Basis of Human Cancer. 2nd ed. Springer

 

Guernet A., Aaronson S.A., Anouar Y and Grumolato L. (2016) Modelling intratumor heterogeneity through CRISPR-barcodes. Mol. Cell Oncol. 3(6):e1227894.

 

Guernet A., Mungamuri S.K., Cartier D., Sachidanandam R., Jayaprakash A., Adriouch S., Vezain M., Charbonnier F., Rohkin G., Coutant S., Yao S., Ainani H., Alexandre D., Tournier I., Boyer O., Aaronson S.A., Anouar Y. and Grumolato L. (2016) CRISPR-Barcoding for Intratumor Genetic Heterogeneity Modeling and Functional Analysis of Oncogenic Driver Mutations. Mol. Cell 63:526-38

 

Grumolato L. and Aaronson, S.A. (2016) Aberrant Signaling Pathways in Cancer. In Holland J.F. and Frei E. Cancer Medicine. 9th ed., Wiley

 

Grumolato L. and Aaronson S.A. (2014) Oncogenes and Signal Transduction. In: Mendelsohn J., Howley P.M., Israel M.A., Gray J.W. and Thompson C.B. The Molecular Basis of Cancer. 4th ed. Philadelphia: Saunders.

 

Mungamuri S.K., Murk W., Grumolato L., Bernstein E. and Aaronson S.A. (2013) Chromatin Modifications Sequentially Enhance ErbB2 Expression in ErbB2-Positive Breast Cancers. Cell Reports S2211-1247(13)00517-2. 10.1016/j.celrep.2013.09.009.

 

Serysheva E., Berhane H., Grumolato L., Demir K., Balmer S., Bodak M., Boutros M., Aaronson S., Mlodzik M. and Jenny A. (2013) Wnk kinases are positive regulators of canonical Wnt/β-catenin signalling. EMBO Reports 14:718-25

 

Grumolato L., Liu G., Haremaki T., Mungamuri S.K., Mong P., Akiri G., Lopez-Bergami P., Arita A., Anouar Y., Mlodzik M., Ronai Z.A., Brody J., Weinstein D.C. and Aaronson S.A. (2013) β-Catenin-independent activation of TCF1/LEF1 in human hematopoietic tumor cells through interaction with ATF2 transcription factors. PLoS Genetics 9: e1003603 1.

 

Manecka D.L., Mahmood F., Grumolato L., Lihrmann I. and Anouar Y. (2013) Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) promotes both survival and neuritogenesis in PC12 cells through activation of nuclear factor-kappaB (NF-kB) pathway involvement of extracellular signal-regulated kinase (ERK), calcium and c-REL. J. Biol. Chem. 288:14936-14948

 

Vijayakumar S. Liu G., Rus I.A.,Yao S., Chen Y., Akiri G., Grumolato L. and Aaronson S.A. (2011) Upregulated autocrine Wnt signaling drives proliferation of multiple human sarcoma subtypes through a novel TCF/-catenin target gene, CDC25A. Cancer Cell 19:601-12

 

Grumolato L., Weber U., and Mlodzik M. (2011). A new piece to the unsolved planar cell polarity puzzle. Dev Cell 20:146-147

 

Asciutti S., Akiri G., Grumolato L., Vijayakumar S. and Aaronson S.A. (2011) Diverse mechanisms of Wnt activation and effects of pathway inhibition on proliferation of human gastric carcinoma cells. Oncogene 30:956-66. Epub 2010 Nov 1

 

Grumolato L., Liu G., Mong P., Mudbhary R., Biswas R., Arroyave R., Vijayakumar S., Economides A.N. and Aaronson S.A. (2010) Canonical and noncanonical Wnts utilize a common mechanism to activate completely unrelated co-receptors. Genes Dev 24:2517-30

 

Funding