Title: Characterisation of the pro-tumourigenic activities of cellular senescence in adamantinomatous craniopharyngioma and preclinical validation of novel therapies
Funder: Cancer Research UK

Abstract: Background: We have previously revealed that the expression of oncogenic beta-catenin in pituitary stem cells leads to formation of tumours in a paracrine manner (Fig. 1). These tumours resemble human adamantinomatous craniopharyngioma (ACP), a challenging paediatric brain tumour of unmet needs, which is associated with substantial morbidity and late mortality. More recently, we have demonstrated that human and mouse ACP contain senescent cells, which are molecularly equivalent, and provided evidence for a causative role for their paracrine activities in cell transformation and tumour initiation in vivo (Fig. 2). Using these unique models as a paradigm, we aim to address fundamental questions on the role of senescence in tumour initiation and progression in ACP, with potential impact on other human tumours and cancers containing senescent cells. Specific questions: (i) Are senescent cells required only tumour initiation or additionally, for tumour growth? (ii) What are the specific paracrine activities underlying the senescent cells’ tumour-inducing potential? (iii) Can the inhibition of senescent cells’ activities reduce ACP tumourigenesis? Aims: Aim 1. Determine the function of senescent cells in tumour initiation and progression through genetic and chemical ablation. We will reveal whether senescent cells are required only for tumour initiation (hit-and-run model) or additionally for tumour growth in vivo. Aim 2. Characterisation of the pro-tumourigenic activities of the senescent cells in mouse and human ACP. Senescence can either promote or suppress tumourigenesis. We will dissect these paradoxical activities in the context of ACP. Aim 3. Preclinical validation of targeted therapies against ACP. We will test novel targeted therapies, some with anti-senescence activities, in vitro and in image-guided preclinical studies. Methods: We will use a multidisciplinary approach combining: (i) Mouse genetics (CRISPR/Cas9 gene targeting, knock-in mice, genetic tracing, conditional deletion). (ii) Cell isolation by flow cytometry and laser capture microdissection (iii) Molecular analyses (RNA-Seq and bioinformatics). (iv) Developmental biology (analysis of mouse embryos bearing tumours during development). (v) MRI-guided preclinical evaluation of targeted therapies. How the results of this research will be used: The proposed research will lead to a better understanding of the role of senescence in the initial stages of tumourigenesis by using unique mouse lines to label, purify, genetically trace and ablate senescent cells in models relevant to human ACP. It will also facilitate translation by identifying potential novel treatments against ACP, which are much needed. The results are expected to impact on other human tumours and cancers that also contain senescent cells.

Lay abstract: Background: We have previously revealed that the expression of oncogenic beta-catenin in pituitary stem cells leads to formation of tumours in a paracrine manner (Fig. 1). These tumours resemble human adamantinomatous craniopharyngioma (ACP), a challenging paediatric brain tumour of unmet needs, which is associated with substantial morbidity and late mortality. More recently, we have demonstrated that human and mouse ACP contain senescent cells, which are molecularly equivalent, and provided evidence for a causative role for their paracrine activities in cell transformation and tumour initiation in vivo (Fig. 2). Using these unique models as a paradigm, we aim to address fundamental questions on the role of senescence in tumour initiation and progression in ACP, with potential impact on other human tumours and cancers containing senescent cells. Specific questions: (i) Are senescent cells required only tumour initiation or additionally, for tumour growth? (ii) What are the specific paracrine activities underlying the senescent cells’ tumour-inducing potential? (iii) Can the inhibition of senescent cells’ activities reduce ACP tumourigenesis? Aims: Aim 1. Determine the function of senescent cells in tumour initiation and progression through genetic and chemical ablation. We will reveal whether senescent cells are required only for tumour initiation (hit-and-run model) or additionally for tumour growth in vivo. Aim 2. Characterisation of the pro-tumourigenic activities of the senescent cells in mouse and human ACP. Senescence can either promote or suppress tumourigenesis. We will dissect these paradoxical activities in the context of ACP. Aim 3. Preclinical validation of targeted therapies against ACP. We will test novel targeted therapies, some with anti-senescence activities, in vitro and in image-guided preclinical studies. Methods: We will use a multidisciplinary approach combining: (i) Mouse genetics (CRISPR/Cas9 gene targeting, knock-in mice, genetic tracing, conditional deletion). (ii) Cell isolation by flow cytometry and laser capture microdissection (iii) Molecular analyses (RNA-Seq and bioinformatics). (iv) Developmental biology (analysis of mouse embryos bearing tumours during development). (v) MRI-guided preclinical evaluation of targeted therapies. How the results of this research will be used: The proposed research will lead to a better understanding of the role of senescence in the initial stages of tumourigenesis by using unique mouse lines to label, purify, genetically trace and ablate senescent cells in models relevant to human ACP. It will also facilitate translation by identifying potential novel treatments against ACP, which are much needed. The results are expected to impact on other human tumours and cancers that also contain senescent cells.

Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: CANCER AND NEOPLASMS