Re-programming by a six-factor-secretome in the patient tumor ecosystem during nutrient stress and drug response

Cancer cells need nutrients to grow and proliferate. During nutrient stress in the microenvironment, it is unclear <i>if</i> or <i>how</i> cancer cells can adopt alternative resources to re-wire and survive in patients. We discovered a 6-factor-secretome remarkably sustains a critical cell mass during nutrient stress in a pediatric embryonal brain tumor, atypical teratoid rhabdoid tumor (ATRT). Specific ATRT subtypes emerged as secretome-enriched, matching macrophage-enrichment patterns and were high-relapse-risk subtypes. The secretome alters drug response, protects against cell death, and provides pro-survival niches to rescue drugged cells. Secretome-grown tumor cells rearrange into a web-like architecture-stable during drug exposure, suggesting a mechanism for therapy resistance. Secretome prevents tumor cell death in aggressive tumor models, and in cerebrospinal dissemination, suggesting a role in tumor resistance/relapse. Our results unravel, a previously unexplored role of a specific 6-factor-secretome, providing an alternative fuel to sustain cancer cells during nutrient stress, and implications in relapse subtypes.