Researchers at University of Maryland Greenebaum Cancer Center have used Roche Diagnostics' Xcelligence system in their study of the involvement of 'microtentacles' in how cancers spread.
Targeting these microtentacles - extensions of the plasma membrane of breast cancer cells - could prove to be a new way to prevent or slow the growth of secondary cancers, the scientists say.
The researchers used the Xcelligence RTCA SP instrument to measure attachment as the relative impedance change, cell index, across the microelectronic sensors at the bottom of the system's E-Plates.
The cytoskeletal organisation of detached and circulating tumour cells (CTCs) is currently not well defined and may provide potential targets for new therapies to limit metastatic tumour spread.
CTCs reattach in vivo in distant tissues by a mechanism that is tubulin-dependent and suppressed by polymerised actin.
The cytoskeletal mechanisms that promote reattachment of CTCs match exactly with the mechanisms supporting tubulin microtentacles (McTN), which the researchers have recently identified in detached breast tumour cells.
The study aimed to investigate how McTN formation is affected by the microtubule-associated protein, tau, which is expressed in a subset of chemotherapy-resistant breast cancers.
The results show that endogenous tau protein localises to McTNs and is both necessary and sufficient to promote McTN extension in detached breast tumour cells.
Tau-induced McTNs increase reattachment of suspended cells and retention of CTCs in lung capillaries.
Analysis of individual-matched primary and metastatic tumours reveals that 52 per cent possess tau-expression in metastases and 26 per cent display significantly increased tau-expression over disease progression.
Tau-enrichment in metastatic tumours and the ability of tau to promote tumour cell reattachment through McTN formation support a model in which tau-induced microtubule stabilisation provides a selective advantage during tumour metastasis.
