Title: Investigating splicing during oncogene-induced senescence: biological role and therapeutic potential
Funder: Cancer Research UK

Abstract: Background: Senescence is a stress response that stably arrest cells exposed to different insults (such as oncogenic activation, tissue damage or chemotherapeutic drugs). Senescence influences cancer progression and therapy outcome in multiple ways. While oncogene-induced senescence (OIS) is triggered in premalignant cells and constitute a potent tumour suppressor mechanism, factors produced as part of the senescence-associated secretory phenotype (SASP) contribute to inflammation, fuelling cancer progression. Recently, targeting senescence (by killing senescent cells or inhibiting the SASP) have been unveiled as a therapeutic approach of relevance for many diseases, including cancer. Independently, research in the last decade has identified splicing alterations occurring in cancer and there is an increasing interest into targeting splicing for cancer therapy. Aims: Despite the focus in alternative splicing as a targetable regulatory mechanism altered in cancer, very little is known on the interplay between OIS and splicing regulation. This proposal intends to characterize this relation and identify functional connections between splicing and OIS with the aim of gain a better understanding of the mechanisms underlying regulation and implementation of senescence, and discover novel therapeutic targets. We will have these specific aims: 1. Characterize the splicing landscape and the splicing machinery during OIS. 2. Investigate the role of the splicing factor PTBP1 on cancer. 3. Identify functional links between splicing and OIS that could be targeted therapeutically. Methods: We will use a multidisciplinary approach that amongst others will combine: - Cell culture systems of oncogene-induced senescence that will be used to derive information on splicing (using RNA-seq, NET-seq combined with cutting edge bioinformatic analysis) and the status of the splicing machinery itself (using microscopy and proteomics). - Functional siRNA screens to assess the role of splicing factors on senescence. - A versatile mouse model of liver cancer initiation and progression to investigate the role of splicing in OIS and tumorigenesis in vivo. - Access to clinical samples of premalignant and cancerous lesions in the liver. - A newly generated mouse model allowing for inducible, reversible Ptbp1 knockdown. How the results of this research will be used: The proposed research will define the interplay between senescence and splicing. This will contribute to a better understanding on senescence regulation. Given the pivotal role of senescence in cancer progression, it will also direct us toward novel therapeutic targets. As senescence is a basic cellular mechanism with multiple pathophysiological roles, the results will have wider implications for cancer and disease.

Lay abstract: Background: Senescence is a stress response that stably arrest cells exposed to different insults (such as oncogenic activation, tissue damage or chemotherapeutic drugs). Senescence influences cancer progression and therapy outcome in multiple ways. While oncogene-induced senescence (OIS) is triggered in premalignant cells and constitute a potent tumour suppressor mechanism, factors produced as part of the senescence-associated secretory phenotype (SASP) contribute to inflammation, fuelling cancer progression. Recently, targeting senescence (by killing senescent cells or inhibiting the SASP) have been unveiled as a therapeutic approach of relevance for many diseases, including cancer. Independently, research in the last decade has identified splicing alterations occurring in cancer and there is an increasing interest into targeting splicing for cancer therapy. Aims: Despite the focus in alternative splicing as a targetable regulatory mechanism altered in cancer, very little is known on the interplay between OIS and splicing regulation. This proposal intends to characterize this relation and identify functional connections between splicing and OIS with the aim of gain a better understanding of the mechanisms underlying regulation and implementation of senescence, and discover novel therapeutic targets. We will have these specific aims: 1. Characterize the splicing landscape and the splicing machinery during OIS. 2. Investigate the role of the splicing factor PTBP1 on cancer. 3. Identify functional links between splicing and OIS that could be targeted therapeutically. Methods: We will use a multidisciplinary approach that amongst others will combine: - Cell culture systems of oncogene-induced senescence that will be used to derive information on splicing (using RNA-seq, NET-seq combined with cutting edge bioinformatic analysis) and the status of the splicing machinery itself (using microscopy and proteomics). - Functional siRNA screens to assess the role of splicing factors on senescence. - A versatile mouse model of liver cancer initiation and progression to investigate the role of splicing in OIS and tumorigenesis in vivo. - Access to clinical samples of premalignant and cancerous lesions in the liver. - A newly generated mouse model allowing for inducible, reversible Ptbp1 knockdown. How the results of this research will be used: The proposed research will define the interplay between senescence and splicing. This will contribute to a better understanding on senescence regulation. Given the pivotal role of senescence in cancer progression, it will also direct us toward novel therapeutic targets. As senescence is a basic cellular mechanism with multiple pathophysiological roles, the results will have wider implications for cancer and disease.

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