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Moore, J. B.

Publications and source records attributed to Moore, J. B..

2 recordsLinked to original sources
bioRxiv2021

Comprehensive profiling of liver x receptor splicing in triple negative breast cancer reveals existence of novel splice variants that are prognostic for survival

The liver x receptors (LXR) alpha and beta are ligand-responsive transcription factors that link homeostatic control of lipid metabolism with cancer pathophysiology and prognosis. LXR activity is elevated in triple negative breast cancer relative to other breast cancer subtypes, driving gene signatures associated with drug resistance and metastasis. The loci encoding LXR and LXR{beta} produce multiple alternatively spliced proteins, but the true range of variants and their relevance to cancer remain poorly defined. Seven splice variants of LXR or LXR{beta} were detected. Three have not been recorded previously and five were prognostic. High expression of full length LXR was associated with shorter disease-free survival but splice variants harbouring truncations of the ligand binding domain were prognostic for improved survival. All LXR{beta} variants were associated with longer disease-free survival. Mechanistically, while full length LXR positively correlated with target gene expression in primary samples, LXR{beta} was inversely correlated. We conclude that canonical LXR function is an oncogenic driver of triple negative tumour pathophysiology that can be countered by high expression of truncated splice variants and/or full length LXR{beta}. HighlightsO_LIExpression of full length LXR is associated with shorter disease-free survival of triple negative breast cancer patients C_LIO_LIA systematic evaluation of cell lines and primary tumour samples indicates LXR splicing is extensive in breast cancer C_LIO_LIConfirmation of three new LXR splice variants at transcript and protein level C_LIO_LIExpression of full length LXR{beta} or LXR splice variants that harbour truncated ligand binding domains are associated with better prognosis C_LIO_LIExpression of LXR target genes is positively correlated with LXR in relapsed patients and inversely correlated with LXR{beta} in survivors. C_LI

cancer biology↗
bioRxiv2020

Liver x receptor alpha drives chemoresistance in response to side-chain hydroxycholesterols in triple negative breast cancer

Triple negative breast cancer (TNBC) is challenging to treat successfully because targeted therapies do not exist. Instead, systemic therapy is typically restricted to cytotoxic chemotherapy, which fails more often in patients with elevated circulating cholesterol. Liver x receptors are ligand-dependent transcription factors that are homeostatic regulators of cholesterol, and are linked to regulation of broad-affinity xenobiotic transporter activity in non-tumor tissues. We show that LXR ligands confer chemotherapy resistance in TNBC cell lines and xenografts, and that LXRalpha is necessary and sufficient to mediate this resistance. Furthermore, in TNBC patients who had cancer recurrences, LXRalpha and ligands were independent markers of poor prognosis and correlated with P-glycoprotein expression. However, in patients who survived their disease, LXRalpha signaling and P-glycoprotein were decoupled. These data reveal a novel chemotherapy resistance mechanism in this poor prognosis subtype of breast cancer. We conclude that systemic chemotherapy failure in some TNBC patients is caused by co-opting the LXRalpha:P-glycoprotein axis, a pathway highly targetable by therapies that are already used for prevention and treatment of other diseases.

cancer biology↗