Rapid Cancer Diagnosis and Prognosis of Metastatic Likelihood Using Mechanobiology

Introduction

The main cause (90%) of cancer-related deaths is due to metastasis. Metastasis requires dynamic adaptation of cells that affects their mechanobiology. We and others have shown that metastatic cells exhibit faster cytoskeletal dynamics, are internally and externally softer than non-invasive cells and can apply stronger adhesive, traction forces as compared to benign. We have previously shown that a subpopulation of metastatic cancer cell-lines will rapidly (

Materials and methods

Cells from cell lines or enzymatically degraded tumor samples (collaborations with Rambam and Carmel Hospitals with Helsinki approvals) are seeded on physiological-stiffness (0.5-10kPa) polyacrylamide gels. Within 1hr of seeding, the invasive cells indent the gels and we determine the subpopulation percentage and their attained depths. Indentation mechanisms are determined by the reduction in indentation after targeted-disruption of different cytoskeleton elements. We concurrently collect (by FACS) specific cell genotypes, e.g. subsets expressing ALDH or CD44 markers, and correlate their indentation capacity.

Results and discussion

We observe that cells indent gels by coordinated reorganization of their cytoskeleton, relying mostly on cytoskeleton dynamics for rapid interactions; cell-substrate interactions of individual cells and clusters vary. We show that the mechanical invasiveness measure is applicable to various solid cancers (e.g. breast, pancreatic and skin cancers), and results match the clinical outcome in patients. We determine cutoffs for diagnosis and prognosis of cancer, identifying normal samples, benign, cancerous, and metastatic.

Conclusions

Our mechanical invasiveness measure reveals a commonality between solid cancers governed by the strength and invasive propensity of the cells. Using this measure we can rapidly predict the clinical outcome in patients and identify target cell-subpopulations for treatment.