Dataset Information

AR Expression in Breast Cancer CTCs Associates with Bone Metastases

ABSTRACT: Molecular drivers underlying bone metastases in human cancer are not well understood, in part due to constraints in bone tissue sampling. Here, we undertook RNA sequencing of circulating tumor cells (CTCs) obtained from blood samples of women with metastatic estrogen receptor (ER)+ breast cancer, comparing cases with progression in bone versus visceral organs. Among the activated cellular pathways in CTCs from bone-predominant breast cancer is Androgen Receptor (AR) signaling. AR gene expression is evident, as is its constitutively active splicing variant AR-v7. AR expression within CTCs is correlated with the duration of treatment with aromatase inhibitors, suggesting that it may contribute to acquired resistance to anti-estrogen therapy. In an established breast cancer xenograft model, a bone-tropic derivative displays increased AR expression, whose genetic or pharmacologic suppression reduces metastases to bone but not to lungs. Together, these observations identify AR signaling in CTCs from women with bone-predominant ER+ breast cancer, and provide a rationale for testing androgen inhibitors in this subset of patients.

ORGANISM(S): Homo sapiens

PROVIDER: GSE86978 | GEO | 2018/02/19

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Prostate cancer is initially responsive to androgen deprivation, but the effectiveness of androgen receptor (AR) inhibitors in recurrent disease is variable. Biopsy of bone metastases is challenging, hence sampling circulating tumor cells (CTCs) may reveal drug resistance mechanisms. We established single cell RNA-sequencing profiles of 77 intact CTCs isolated from 13 patients (mean 6 CTCs/patient) using microfluidic enrichment. Single CTCs from each individual display considerable heterogeneity, including expression of AR gene mutations and splicing variants. Retrospective analysis of CTCs from patients progressing on AR inhibitor, compared with untreated cases indicates activation of noncanonical Wnt signaling (P=0.0064). Ectopic expression of Wnt5a in prostate cancer cells attenuates the antiproliferative effect of AR inhibition, while its suppression in drug-resistant cells restores partial sensitivity, a correlation also evident in an established mouse model. Thus, single cell analysis of prostate CTCs reveals heterogeneity in signaling pathways that could contribute to treatment failure. A total of 221 single candidate prostate CTCs were isolated from 18 patients with metastatic prostate cancer and 4 patients with localized prostate cancer. Of these, 133 cells (60%) had RNA of sufficient quality for amplification and next generation RNA sequencing, and 122 (55%) had >100,000 uniquely aligned sequencing reads. In addition to candidate CTCs, we also obtained comprehensive transcriptomes for 12 bulk primary prostate cancers (macrodissected for >70% tumor content), 30 single cells derived from four different prostate cancer cell lines, and 5 patient-derived leukocyte controls. The leukocytes were readily distinguished by their expression of hematopoietic lineage markers and served to exclude any CTCs with potentially contaminating signals. Strict expression thresholds were used to define lineage-confirmed CTCs, scored by prostate lineage-specific genes (PSA, PSMA, AMACR, AR) and standard epithelial markers (KRT7, KRT8, KRT18, KRT19, EpCAM). 28 cells were excluded given the presence of leukocyte transcripts suggestive of cellular contamination or misidentification during selection, and 17 cells were excluded given low expression of both prostate lineage-specific genes and 5 standard epithelial markers. The remaining 77 cells, defined as lineage-confirmed CTCs, displayed expression of either prostate lineage-specific or epithelial genes, and low expression of leukocyte-specific genes, consistent with their tumor of origin.

Dataset Information

AR Expression in Breast Cancer CTCs Associates with Bone Metastases

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets