Related Experiment Video
Updated: Oct 15, 2025

Modeling Breast Cancer via an Intraductal Injection of Cre-expressing Adenovirus into the Mouse Mammary Gland
Published on: June 7, 2019
PER1 as a Tumor Suppressor Attenuated in the Malignant Phenotypes of Breast Cancer Cells
Yinfeng Liu1,2, Jun Hao3, Guanli Yuan4
1Department of Breast Disease Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050000, People's Republic of China.
Background:
Circadian clock genes play a crucial role in physiological and pathological processes, and their aberrant expressions were involved in various human cancers. The objective of this study was to investigate the expression level of Period circadian regulator 1 (PER1), an important circadian clock gene, and its biological roles in the development and progression of breast cancer.
Methods:
The expression level of PER1 in breast cancer samples was analyzed using the Oncomine database, and the correlation between PER1 expression and clinicopathologic parameters was assessed by bc-GenExMiner v4.5. In addition, Kaplan-Meier plotter database was used to determine the prognostic significance of PER1 expression for breast cancer patients. The expressions of PER1 in breast cancer tissues and cells were validated by Western blot. The loss-or-gain assay of PER1 was conducted to investigate the effects of its expression on cell proliferation, migration and invasion of breast cancer. The relationship between PER1 expression and epigenetic modifications was further explored by Western blot.
Results:
The results of the bioinformatics analysis revealed that the expression level of PER1 was markedly reduced in breast cancer tissues (P<0.001), and patients with high expression of PER1 had a better overall survival (HR:0.78, 95% CI:0.63-0.97, P=0.026) and recurrence-free survival (HR:0.83, 95% CI:0.75-0.93, P=0.001) than those with low expression. The assay of gene loss-or-gain indicated that downregulation of PER1 expression markedly promoted cell proliferation, migration and invasion (P<0.05), whereas these malignant phenotypes of breast cancer cells were inhibited by PER1 overexpression (P<0.05). Further studies showed that trichostatin A (TSA), a histone deacetylase inhibitor, induced the expression of PER1 protein in breast cancer cells (P<0.05).
Conclusion:
PER1 functions as a tumor suppressor in the development and progression of breast cancer, and its expression silencing might be regulated by epigenetic modifications.
More Related Videos
11:47Time-lapse Imaging of Primary Preneoplastic Mammary Epithelial Cells Derived from Genetically Engineered Mouse Models of Breast Cancer
Published on: February 8, 2013
09:37Defining Gene Functions in Tumorigenesis by Ex vivo Ablation of Floxed Alleles in Malignant Peripheral Nerve Sheath Tumor Cells
Published on: August 25, 2021
Related Concept Videos
Abnormal Proliferation
Loss of Tumor Suppressor Gene Functions
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
Cancer-Critical Genes II: Tumor Suppressor Genes
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
Mitogens and the Cell Cycle
Cancer-Critical Genes I: Proto-oncogenes
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...