Exploring the Impact of Senescent Stromal Cells on Tumor Cell Stemness

Aging is a great risk factor for cancer. Many types of cancer get more aggressive with aging. Cancer stem cells play a critical role during cancer progression and recurrence, which might enhance aging-associated cancer aggressiveness. At the cellular level, senescent cell accumulation is a main cause of aging. While senescence is traditionally considered a tumor-suppressive mechanism, recent studies suggest that senescent stromal cells may exert paradoxical effects on the stemness properties of adjacent tumor cells. This study delves into the interplay between tumor stromal cell senescence and the stemness in lung cancer cells. We investigated the impact of senescent MRC5 conditioned medium on tumor cell behavior. Initial experiments revealed that MRC5 stromal lung fibroblast induced a robust senescent state by H2O2 and carboplatin. Subsequent investigations using colony formation assays underscored an augmented clonogenic potential in cells cultured with senescent MRC5 conditioned medium, indicative of heightened tumor cell stemness. Expanding our analysis to drug resistance, we observed a pronounced resistance to carboplatin in tumor cells exposed to senescent MRC5 conditioned medium. To decipher the molecular underpinnings of these phenotypic changes, we quantified the expression of cancer stemness markers, revealing a specific pattern of upregulation. These findings collectively highlight the impact of senescent stromal cells on tumor cells stemness, indicating a distinctive molecular signature associated with the acquisition of stem-like properties. Understanding these complexities contributes to our knowledge of tumor heterogeneity and may inform novel therapeutic strategies.