Document Type


Date of Award



College of Science, Engineering, and Technology (COSET)

Degree Name

MS in Biology

Committee Chairperson

Audrey N Player

Committee Member 1

Ayodotun Sodipe

Committee Member 2

Mario Hollomon

Committee Member 3

Tuan D Phan


• African American Breast cancer, Estrogen Receptor progesterone receptor HEE 2, Genetic Differences, Microarray, Triple Negative Breast Cancer


Triple negative breast cancers (TNBC) are closely related to basal-like cancers and classified based on their molecular signatures and their progenitor cell type. TNBCs lack the presence of three common types of receptors known to fuel breast cancer growth: estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptors 2 (HER2neu). TNBC represent 10-20% of all molecular breast cancer subtypes. Even though genomic and transcriptome analyses show that many of the molecular signatures associated with TNBC are not related to ethnicity, clinicians and researchers find that African American (AA) TNBC women have higher mortality rates compared to Caucasian (CA) women. The high mortality rates are linked to socioeconomic factors like access to adequate healthcare, but researchers are exploring the possibility that genetic differences between AA and CA patients may also play a role in racial disparities. Microarray analyses have been instrumental in characterizing TNBC and many other types of breast cancer. Related to TNBC, microarray analyses (a) validate the negative receptor-status of the cancers (b) identify and define the six sub-categories of TNBC validating the heterogeneity of the cancers as defined by Lehmann et al and (c) the microarray gene expression platform is proving to be useful towards determining genes differentially represented in AA and CA TNBC. Our approach is to use the microarray platform (and a cell line model) to further examine the differences between the transcriptomes of CA and AA women. For more accurate transcriptome comparisons, we’ve identified and compared AA Basal-A TNBC to CA Basal-A TNBC, and separately AA Basal-B TNBC compared to CA Basal-B TNBC. Bioinformatic analyses show that TCEAL8 and TCEAL9 genes, both located on X-chromosome are differentially expressed in AA compared to CA TNBC. The EFHD1 gene is identified as differentially expressed in AA Basal-B compared to CA Basal- B TNBC. These data serve as a preliminary study towards further characterizing molecular differences between the transcriptomes of AA compared to CA TNBC patient populations.