SUM159PT Cells

The SUM159PT cell line is derived from an anaplastic carcinoma of the breast and is a model for triple-negative breast cancer (TNBC), a subtype lacking estrogen receptor (ER), progesterone receptor (PR), and HER2 expression. SUM159PT is characterized by its aggressive phenotype, anchorage-independent growth, and invasive potential, making it particularly valuable for studying TNBC biology and therapy.

Genetic analysis of SUM159PT has revealed notable amplifications and deletions common in aggressive breast cancers. These include amplifications at chromosomal loci such as 8q (containing MYC) and losses at 8p, which are implicated in tumor progression. The line is aneuploid, consistent with many cancer cell lines, and shows alterations in pathways critical to proliferation and apoptosis. SUM159PT also exhibits basal-like features and expresses cytokeratins 5/6 and 14, markers associated with basal-type breast cancers. These characteristics reinforce its utility in modeling basal-like TNBC and exploring novel therapeutic approaches.

Sensitivity studies on SUM159PT have highlighted its response to BET bromodomain inhibitors such as JQ1, which target epigenetic regulators like BRD4. Treatment with JQ1 induces significant morphological changes, including senescence and basal-to-luminal differentiation, while inhibiting proliferation and promoting apoptosis. These effects underscore the role of transcriptional control in TNBC survival and suggest potential for combination therapies targeting epigenetic regulators in resistant TNBC subtypes. This cell line is extensively used in both in vitro assays and in vivo xenograft models to evaluate the efficacy of new treatments.