Poster Presentation 32nd Lorne Cancer 2020

Defining the prostate tumour-stroma secretome to understand intercellular communication (#370)

Yunjian Wu 1 2 , Elizabeth Nguyen 1 2 , Birunthi Niranjan 1 3 , Hugh Ma 1 2 , Renea Taylor 1 4 5 , Roger Daly 1 2
  1. BDI, Monash University, Clayton, VIC, Australia
  2. Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia. , Melbourne
  3. Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia, Melbourne
  4. Cancer Research Division, Peter MacCallum Cancer Centre, Victorian Comprehensive Cancer Centre, Parkville, Australia, Melbourne
  5. Department of Physiology, Monash University, Clayton, Australia, Melbourne

Background and objective

Cancer associated fibroblasts (CAFs) play an important role in prostate cancer (PC) development and progression, yet the specific mechanisms of intercellular communication between CAFs and prostate epithelium (PE) or PC cells remain poorly defined. The aim of this study is to characterize the dynamic interplay of CAFs with either PE or PC cells in a co-culture system. We focused on secreted factors that altered in abundance upon co-culture vs mono-culture to identify potential therapeutic targets and also novel biomarkers of early disease and prognosis.

Methods

PC3 (a PC cell line)or BPH-1 cells (a PE cell line) were individually co-cultured with either primary non-malignant prostate fibroblasts (NPFs) or their CAF counterparts, both derived from 2 pairs of patient-matched samples. The co-culture conditioned medium (CM), together with corresponding mono-culture CM, was collected and analysed using a human antibody array covering 200 different inflammation factors, growth factors, cytokines, chemokines and receptors (n=2). CTAP mass spectrometry-based proteomics was used to delineate the origin of the contributing secreted factors.

Results

The antibody array detected 116 proteins in BPH-1 co-cultured with NPFs or CAFs. Ten proteins showed increased abundance in co-culture(>10 fold change) in comparison to BPH-1, NPF, and the CAF mono-culture systems. Two proteins showed decreased abundance in co-culture(>2 fold change) compared to the mono-culture systems. There were 96 proteins identified in PC3 co-cultured with NPFs or CAFs. Eleven proteins exhibited increased abundance(>10 fold change) compared to any of the mono-culture systems. A replicate antibody array confirmed 6(CXCL10, CXCL6, CXCL16, Follistatin, IL-17B, PDGF-A) proteins up-regulated in co-culture and 4(CXCL4, CCL7, HGF, BDNF) proteins down-regulated in co-culture compared to mono-culture.

Conclusion

A distinct cellular secretome was observed upon co-culture of PC or PE cells with NPFs or CAFs compared to the corresponding mono-cultures, indicating that intercellular communication alters the cellular secretion pattern. Further functional validation will be performed on key candidates to determine their potential as novel PC biomarkers or therapeutic targets.