Abstract A28: Bioenergetic analysis of primary human mammary epithelial cells (hMECs)

• Published in: Molecular cancer research 2016-01, Vol.14 (1_Supplement), p.A28-A28
• Main Authors: Henchey, Elizabeth M., Schneider, Sallie S., Jerry, D. Joseph, Yadava, Nagendra
• Format: Article
• Language: English
• ISSN: 1541-7786; 1557-3125
• DOI: 10.1158/1557-3125.METCA15-A28

We have demonstrated reversible suppression of the tumor suppressor protein p53 by respiratory chain deficiency. Further, a recent study from a different group also suggests genetic inactivation of p53 by the impairments of oxidative metabolism, and mutations in mtDNA and TP53 gene coexist in cancers. Therefore, we predict that variation in oxidative metabolism can result in differences in p53 response among individuals. Conditions that suppress oxidative metabolism can impair p53, and thereby promote cancer development. Toward testing this hypothesis, our approach is to quantify the variation in respiratory activity of normal human mammary epithelial cells (hMECs), and then determine the correlation between respiratory activity and p53 response. Thus, we have performed in situ respirometry using 24-well Seahorse Bioscience's Extracellular Flux (XF) Analyzer on hMECs (at passage 2) isolated from breast cancer patients (n=23). The hMECs were isolated from cancer affected (AB) and non-affected (NAB) breasts and differences in parameters affecting mitochondrial bioenergetics under normal and treated (IGF1, TNFα;) conditions were assessed. Our data show 6-9 fold variation in hMECs basal respiratory activity (n=23). Further, 48%, 30% and 22% of patients showed either no difference in mitochondrial respiratory capacity upon addition of pyruvate (-2±5%), or showed at least 10% increase (26±18%) or decrease (-15±3%), respectively. Treatments with selected cytokines such as IGF1 and TNFα; for 24 hours altered the mitochondrial bioenergetics of hMECs. Overall they reduced respiratory activity in cells; and altered response to pyruvate addition in some individuals. Interestingly, matched normal hMECs from affected (AB) and not affected (NAB) breasts showed differences in the respiratory activity even at passage 2 suggesting that local environments play a critical role in the bioenergetics of normal cells and these changes do not revert ex vivo immediately when cells are removed from their environment. Acknowledgements: This work was supported by funds from Rays of Hope and Incubator grants from the Baystate Health Foundation, CEAR at the PVLSI supported by an award (A00000000004448) from Massachusetts Technology Collaborative as administrator of the John Adams Innovation Institute. Citation Format: Elizabeth M. Henchey, Sallie S. Schneider, D. Joseph Jerry, Nagendra Yadava. Bioenergetic analysis of primary human mammary epithelial cells (hMECs). [abstract]. In: Proce