Abstract C109: Identifying a novel metabolic reprogramming strategy to inhibit diabetes-associated TNBC in African American
Authors: Hao Qiongyu , Wu Yong , Wu Yanyuan , Vadgama Jaydutt 
Published: September 2024

Cancer cells have an increased glucose metabolism, primarily characterized by augmented glucose uptake and aerobic glycolysis, converting glucose into pyruvate, eventually producing lactate. Breast cancer (BC) is the most commonly diagnosed cancer and the second leading cause of death among women in the United States. The triple-negative breast cancer (TNBC) subgroup is the most aggressive, metastatic, and refractory because of the absence of the three characteristic receptors: Estrogen (ER), progesterone (PR), and human epidermal growth factor (Her2/neu), representing approximately 10-15% of all BC cases. Racial disparities analysis demonstrates that African American (AA) has a higher incidence of TNBC subtype, with an earlier onset, more advanced stage, more aggressive histologic features, and poor survival, compared to other ethnic groups. Hyperglycemia affects the cancer progression through metabolic reprogramming and molecular alterations. AA women with Type 2 diabetes (T2D) are at increased risk of developing ER-negative BC. The reasonable combination therapy of metformin with NF-𝜅Bi and MCT4i, is promising because it can rapidly disable tumor cell growth but with a minor effect on normal cells, holding promise as an anti-BC treatment. Because of the potential side effects of MCT4 inhibitors and the potent inhibitory effect of microRNA on target genes, we consider using microRNA instead of inhibitors to suppress MCT4 expression. We will investigate the anti-diabetes-associated TNBC effect of the MRS, consisting of blocking lactate export via MCT4 degradation by miR-206, in combination with promoting lactate production via forcing glycolysis with metformin and NF-𝜅Bi treatment, in a preclinical study of AA women. Moreover, our previous study and other studies have also shown an elevated expression of Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) in BC tissues and cells, particularly in metastatic TNBC. We will also explore the molecular mechanisms by which high glucose (HG) leads to lactate accumulation in BC cells. Our overall strategy is that excessive glucose uptake upregulates the MCT4 through a MALAT1/miR-206/MCT4 axis, miR-206-directed MRS shifts glucose metabolism from Oxidative phosphorylation (OXPHOS) to glycolysis, increasing lactate production. Meanwhile, blocking the export of excessive lactate through MCT4 degradation causes high intracellular lactate accumulation and a decrease in intracellular pH (pHi), resulting in metabolic crisis and BC cell death. Due to a complex interplay between hyperglycemia and cancer, antihyperglycemic drugs have often been devised in combination with anticancer drugs for cancer treatment. Our proposed approach will broadly impact the field by providing a novel idea for therapies targeting cancer cell lactate metabolism. In the long term, these studies may reveal an effective therapeutic strategy for diabetes-associated BC, especially in AA women.

Citation Format: Qiongyu Hao, Yong Wu, Yanyuan Wu, Jaydutt Vadgama. Identifying a novel metabolic reprogramming strategy to inhibit diabetes-associated TNBC in African American [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C109.