Submitter Withdrawn 34th Lorne Cancer Conference 2022

The origin and contribution of cancer-associated fibroblasts in colorectal carcinogenesis (#333)

Hiroki Kobayashi 1 2 3 , Krystyna Gieniec 2 , Tamsin RM Lannagan 2 , Tongtong Wang 1 2 , Naoya Asai 4 , Yasuyuki Mizutani 3 5 , Tadashi Iida 3 5 , Ryota Ando 3 , Elaine M Thomas 2 , Akihiro Sakai 3 , Nobumi Suzuki 1 2 , Mari Ichinose 1 2 , Josephine A Wright 1 , Laura Vrbanac 2 , Jia Q Ng 2 , Jarrad Goyne 1 , Georgette Radford 2 , Matthew J Lawrence 6 , Tarik Sammour 6 , Yoku Hayakawa 7 , Sonja Klebe 8 , Alice E Shin 9 , Samuel Asfaha 10 , Mark L Bettington 11 12 13 , Florian Rieder 14 , Nicholas Arpaia 15 , Tal Danino 15 , Lisa M Butler 1 2 , Alastair Burt 2 , Simon J Leedham 16 , Anil K Rustgi 15 , Masahide Takahashi 3 , Tim Wang 15 , Atsushi Enomoto 3 , Daniel Worthley 1 17 , Susan L Woods 1 2
  1. Precision Medicine, SAHMRI, Adelaide, SA, Australia
  2. Medical School, University of Adelaide, Adelaide, SA, Australia
  3. Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
  4. Dept Molecular Pathology, Fujita Health University, Toyoake, Aichi, Japan
  5. Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
  6. Department of Surgery, Royal Adelaide Hospital, Adelaide, SA, Australia
  7. Department of Gastroenterology, The University of Tokyo, Tokyo, Japan
  8. Department of Anatomical Pathology, Flinders Medical Centre, Bedford Park, SA, Australia
  9. Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
  10. Department of Medicine, University of Western Ontario, London, ON, Canada
  11. Envoi Specialist Pathologists,, Kelvin Grove, QLD, Australia
  12. Faculty of Medicine, University of Queensland, Herston, QLD, Australia
  13. QIMR Berghofer, Herston, QLD, Australia
  14. Department of Gastroenterology, Hepatology, and Nutrition, Digestive Diseases and Surgery Institute, Cleveland, OH, USA
  15. Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA
  16. Wellcome Trust Centre Human Genetics, University of Oxford, Oxford, UK
  17. Colonoscopy Clinic, Brisbane, QLD, Australia

Cancer-associated fibroblasts (CAFs) play an important role in colorectal cancer (CRC) progression and predict poor prognosis in CRC patients. However, the cellular origins of CAFs remain unknown, making it challenging to therapeutically target these cells.

Here, we aimed to identify the origins and contribution of colorectal CAFs associated with poor prognosis.

To determine the origin of CRC CAFs, we induced colitis-associated CRC in 5 different fate-mapping transgenic mouse lines with BrdU dosing to label newly born cells. RNA-sequencing of fluorescence activated cell sorting (FACS)-purified CRC CAFs was also performed to identify potential therapeutic targets in CAFs. To examine the prognostic significance of the key stromal targets we identified, we used CRC patient RNA-sequencing data and tissue microarrays. CRC organoids were injected into the colon of newly generated knockout mice to assess the mechanism by which one stromal gene target contributes to colorectal tumorigenesis.

Our lineage-tracing studies revealed that, in CRC, many ACTA2 + CAFs emerge through proliferation from intestinal pericryptal Leptin receptor (Lepr)+ cells. These Lepr -lineage CAFs, in turn, express melanoma cell adhesion molecule (MCAM/CD146), a CRC stroma-specific marker we identified using RNA-sequencing of sorted populations. High MCAM expression induced by TGF-β was inversely associated with patient survival in human CRC. In mice, stromal Mcam knockout attenuated orthotopically injected colorectal tumouroid growth and improved survival through decreased tumour-associated macrophage recruitment. Mechanistically, fibroblast MCAM interacted with interleukin-1 receptor 1 to augment nuclear factor-ĸB-IL34/CCL8 signalling that promotes macrophage chemotaxis.

In summary we have shown that during colorectal carcinogenesis, pericryptal Lepr-lineage cells proliferate to generate MCAM + CAFs that shape the tumour-promoting immune cold microenvironment. Preventing the expansion/differentiation of Lepr -lineage CAFs or inhibiting MCAM activity could be effective therapeutic approaches to treat immune-cold CRC.