Publications by authors named "Maria C Donaldson"

In diffuse large B-cell lymphoma (DLBCL), activation of the B-cell receptor (BCR) promotes multiple oncogenic signals, which are essential for tumor proliferation. Inhibition of the Bruton's tyrosine kinase (BTK), a BCR downstream target, is therapeutically effective only in a subgroup of patients with DLBCL. Here, we used lymphoma cells isolated from patients with DLBCL to measure the effects of targeted therapies on BCR signaling and to anticipate response.

View Article and Find Full Text PDF

Molecular drivers underlying bone metastases in human cancer are not well understood, in part due to constraints in bone tissue sampling. Here, RNA sequencing was performed of circulating tumor cells (CTC) isolated 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.

View Article and Find Full Text PDF

is a tumor suppressor in follicular lymphoma that controls mTORC1 activity and it is inactivated by chromosomal deletions or epigenetically silenced by mutant EZH2. Pharmacological inhibition of EZH2 promotes re-expression and it restores its tumor suppressive activity, suggesting the possibility to epigenetically control mTORC1 activity.

View Article and Find Full Text PDF
Article Synopsis
  • Follicular lymphoma (FL) is an incurable B cell lymphoma characterized by specific genetic abnormalities, including the t(14;18) translocation and losses of chromosome 6q.
  • Researchers identified a gene linked to the 6q deletion that plays a role in tumor suppression and is affected by a lymphoma-specific mutation, disrupting p53's regulation of mTORC1, which is crucial for mRNA translation under stress.
  • The effectiveness of EZH2 inhibition in treating lymphoma relies on the protein SESTRIN1, which impacts mTORC1 activity; patients with mutations in SESTRIN1 may respond better to mTOR inhibitors like RapaLink-1.
View Article and Find Full Text PDF

Cancer cells metastasize through the bloodstream either as single migratory circulating tumor cells (CTCs) or as multicellular groupings (CTC clusters). Existing technologies for CTC enrichment are designed to isolate single CTCs, and although CTC clusters are detectable in some cases, their true prevalence and significance remain to be determined. Here we developed a microchip technology (the Cluster-Chip) to capture CTC clusters independently of tumor-specific markers from unprocessed blood.

View Article and Find Full Text PDF

Circulating tumor cell clusters (CTC clusters) are present in the blood of patients with cancer but their contribution to metastasis is not well defined. Using mouse models with tagged mammary tumors, we demonstrate that CTC clusters arise from oligoclonal tumor cell groupings and not from intravascular aggregation events. Although rare in the circulation compared with single CTCs, CTC clusters have 23- to 50-fold increased metastatic potential.

View Article and Find Full Text PDF

Circulating tumor cells (CTCs) are present at low concentrations in the peripheral blood of patients with solid tumors. It has been proposed that the isolation, ex vivo culture, and characterization of CTCs may provide an opportunity to noninvasively monitor the changing patterns of drug susceptibility in individual patients as their tumors acquire new mutations. In a proof-of-concept study, we established CTC cultures from six patients with estrogen receptor-positive breast cancer.

View Article and Find Full Text PDF

Epithelial-mesenchymal transition (EMT) of adherent epithelial cells to a migratory mesenchymal state has been implicated in tumor metastasis in preclinical models. To investigate its role in human cancer, we characterized EMT in circulating tumor cells (CTCs) from breast cancer patients. Rare primary tumor cells simultaneously expressed mesenchymal and epithelial markers, but mesenchymal cells were highly enriched in CTCs.

View Article and Find Full Text PDF