Project description:Early full-term pregnancy affords lifetime protection against development of breast cancer. Parity-induced protection can be reproduced in a carcinogen-induced rat mammary carcinoma model. The molecular mechanisms of parity-induced protection against carcinogenic stimuli in rat mammary glands have not been fully characterized. In order to gain a better understanding of these molecular mechanisms, we performed gene expression analyses in parous and age-matched virgin (AMV) mammary glands of Lewis rats before and after carcinogen (N-methyl-N-nitrosourea; MNU) treatment. Keywords: other
Project description:Early full-term pregnancy affords lifetime protection against development of breast cancer. Parity-induced protection can be reproduced in a carcinogen-induced rat mammary carcinoma model. The molecular mechanisms of parity-induced protection against carcinogenic stimuli in rat mammary glands have not been fully characterized. In order to gain a better understanding of these molecular mechanisms, we performed gene expression analyses in parous and age-matched virgin (AMV) mammary glands of Lewis rats before and after carcinogen (N-methyl-N-nitrosourea; MNU) treatment.
Project description:Mammary gland development: cross-species analysis of the mammary gland transcriptome in pregnant or lactating wild type female Sprague Dawley rats.
Project description:Male Sprague-Dawley rats were used to establish exhausted-exercise model by motorized rodent treadmill. Yu-Ping-Feng-San at doses of 2.18 g/kg was administrated by gavage before exercise training for 10 consecutive days. Quantitative proteomics was performed for assessing the related mechanism of Yu-Ping-Feng-San.
Project description:Age and parity are well-known factors that influence breast cancer development (1-3). Epidemiological studies have shown that women who have had multiple pregnancies are at a lower risk of developing breast cancer than women who have no history of pregnancy (4, 5). However, mechanisms that link parity and cancer protection are unclear. We discovered that CD8+ T cells with a tissue-resident memory (TRM) phenotype enriched in the mammary glands of parous women and mice compared to their virgin counterparts. Developmental kinetics revealed that these cells seeded the mammary gland during early gestation but persisted post lactation and was specific to the mammary glands. While these CD8 T cells expressed the TRM specific transcription factor Hobit, single cell transcriptomics revealed expansion of transcriptionally distinct canonical and non-canonical TRM populations, including a novel Hobit+ innate T cells (ITCs) in the parous mammary gland compared to their virgin counterparts. Furthermore, imaging analysis uncovered that the TRM like cells were associated with mammary epithelial cells and impairment in mammary gland branching during pregnancy significantly affected their differentiation or population expansion. In keeping with their association with mammary epithelial cells, all TRM subsets, including the Hobit+ITCs commonly required the cytokines TGF-β and IL-15 for their differentiation. Notably, depletion of CD103+ T cells exacerbated tumour growth in parous mice and lineage tracing experiments revealed that the canonical TRM like cells switched to an effector phenotype in tumours and contributed to tumour control. Together, we show for the first time that parity induces novel and heterogenous TRM like populations in the mammary gland that are central in providing protection against breast cancer.