Table 1. Distinct metastatic lesions originating from a common cell line exhibit niche-dependent molecular signatures.

Cancerous cells isolated from adrenal and bones were cultured ex vivo and analyzed for changes in biomarker expression with a hematopoietic array. Cellular markers upregulated in adrenal-tropic lines were typically associated with increased tumor growth and invasion, while those upregulated in the bone-tropic line act to promote bone resorption

PROTEINS UPREGULATED IN ADRENAL-TROPIC MCF7-6124A CELLS
Protein	Fold Change	Pathway activated	Clinical relevance
N-Cadherin	4.75	Sustains activation of ERK and activates MMP-9 production	Promotes invasive activity and increases tumor metastasis
ADAM17	6.5	Activates EGFR-MEK-ERK pathway and upregulates MMP-2 and MMP-9, stimulates the release of TGFα	Increases cellular invasion and proliferation
JAM-A	4.5	Activates Rap1 GTPase and upregulates β1-integrin	Increases cell motility Indicates poor patient prognosis
PROTEINS UPREGULATED IN BONE-TROPIC MCF7-5624A CELLS
Notch-1	2	Activated by downstream products of TGFβ-SMAD pathway to promote osteoclast differentiation in bone	Promotes bone reabsorption and osteolytic lesions
Amphiregulin	2	Stimulates and increases EGFR signaling	Important for bone colonization
EGFR	2.27	Activation with MMP-1 leads to reduced production of osteoprotegrin, increasing RANKL activation of osteoclasts	Impacts recruitment of osteoblasts, limiting bone mineralization