Precision of flow sensing by self-communicating cells

TL;DR

This paper analyzes how self-communicating cancer cells detect lymphatic flow direction, comparing absorption and reversible binding, and finds that reversible binding offers higher precision, aligning with experimental data.

Contribution

It derives the detection precision for self-communicating cells using absorption and binding, revealing binding's superior accuracy and its near-physical detection limit.

Findings

Binding provides more precise flow sensing than absorption.

Cancer cells operate close to the physical detection limit.

Reversible binding is supported by endocytosis data.

Abstract

Metastatic cancer cells detect the direction of lymphatic flow by self-communication: they secrete and detect a chemical which, due to the flow, returns to the cell surface anisotropically. The secretion rate is low, meaning detection noise may play an important role, but the sensory precision of this mechanism has not been explored. Here we derive the precision of flow sensing for two ubiquitous detection methods: absorption vs.\ reversible binding to surface receptors. We find that binding is more precise due to the fact that absorption distorts the signal that the cell aims to detect. Comparing to experiments, our results suggest that the cancer cells operate remarkably close to the physical detection limit. Our prediction that cells should bind the chemical reversibly, not absorb it, is supported by endocytosis data for this ligand-receptor pair.