Abstract P5-12-13: Exploring the impact of the tumor microenvironment on nuclear morphometry: Lessons learned for sensitivity to cytotoxic treatment

Abstract

Abstract Globally, breast cancer remains the leading cause of death in females. While systemic therapy for breast cancer may work effectively in the early phases, for more than 10% of primary and 50% of metastatic cases, the disease eventually progresses, resisting treatments. To overcome this issue, recognizing markers of resistance as early as possible is critical. Microenvironmental factors influence tumors, and increased stiffness of the extracellular matrix (ECM) is associated with cancer progression. Additionally, neighboring cells such as non-neoplastic epithelial cells(that may constitute an important portion of the tumor microenvironment -TME) are suspected to affect tumors, but details on their impact are lacking. Here, we asked whether the response to increased ECM stiffness differed depending on the degree of aggressiveness of triple negative breast cancers (TNBC) and the presence of the non-neoplastic epithelium. We investigated two morphometric parameters, nuclear circularity and area (used in cancer pathology), and tumors’ sensitivity to cisplatin to assess tumor aggressiveness- with TNBC cultured at normal (770 Pa) and increased (2000 and 3300 Pa) collagen I stiffness. Reduced nuclear circularity and increased heterogeneity for this parameter in the cancer cell population resulted from higher matrix stiffness and were associated with decreased sensitivity to the cytotoxic drug, cisplatin, notably in the more invasive cancer type. Interestingly, the impact of stiffness increase was reduced by the conditioned medium from the non-neoplastic cells. These findings warrant further investigations to identify whether changes in nuclear circularity that illustrate a global nuclear reorganization affect gene expression profiles linked to cell survival. Citation Format: Apekshya Chhetri. Exploring the impact of the tumor microenvironment on nuclear morphometry: Lessons learned for sensitivity to cytotoxic treatment [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-12-13.