Mediator Subunit Med4 Enforces Metastatic Dormancy in Breast Cancer
Seong-Yeon Bae1,2,3,4, Hsiang-Hsi Ling1,2,3,4, Yi Chen2,5,6
1Cancer Metastasis Initiative, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, New York 10032, USA.
Biorxiv : the Preprint Server for Biology
|November 28, 2023
Summary
Med4 protein acts as a gatekeeper for dormant breast cancer cells, preventing their reactivation and metastatic growth. Its deficiency is linked to poorer patient prognosis, highlighting Med4 as a potential biomarker for high-risk relapse.
Area of Science:
- Cancer Biology
- Molecular Oncology
- Epigenetics
Background:
- Long-term survival in breast cancer patients is often compromised by recurrence from metastatic dormant cancer cells.
- The precise mechanisms governing the survival and reactivation of these dormant cells are not well understood.
Purpose of the Study:
- To identify novel regulators of metastatic reactivation in breast cancer.
- To elucidate the role of Med4 in maintaining cancer cell dormancy and metastatic potential.
Main Methods:
- Genome-scale genetic screen in mice to identify genes involved in metastatic reactivation.
- Syngeneic xenograft models to study the function of Med4 in breast cancer dormancy.
- Chromatin immunoprecipitation and gene expression analysis to investigate Med4's regulatory mechanisms.
Main Results:
- Med4 was identified as a critical gatekeeper suppressing metastatic reactivation.
- Med4 haploinsufficiency, prevalent in metastatic breast cancer patients, correlates with poorer prognosis.
- Med4 maintains 3D chromatin compaction and suppresses enhancer priming by inhibiting H3K4me1 deposition, thereby enforcing dormancy.
- Med4 deficiency disrupts enhancer dynamics, promoting extracellular matrix gene expression and driving metastatic growth.
Conclusions:
- Med4 is a key regulator of cellular dormancy in breast cancer.
- Med4 functions uniquely within the Mediator complex to maintain chromatin structure and prevent metastatic reactivation.
- Med4 serves as a potential biomarker for predicting high-risk metastatic relapse in breast cancer patients.
Related Concept Videos
02:23Abnormal Proliferation
4.5K
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the...
4.5K
02:30Metastasis
5.6K
Metastasis is the spread of cancer cells from the original site to distant locations in the body. Cancer cells can spread via blood vessels (hematogenous) as well as lymph vessels in the body.
Epithelial-to-Mesenchymal Transition
The epithelial-to-mesenchymal transition or EMT is a developmental process commonly observed in wound healing, embryogenesis, and cancer metastasis. EMT is induced by transforming growth factor-beta (TGF-β) or receptor tyrosine kinase (RTK) ligands, which further...
Epithelial-to-Mesenchymal Transition
The epithelial-to-mesenchymal transition or EMT is a developmental process commonly observed in wound healing, embryogenesis, and cancer metastasis. EMT is induced by transforming growth factor-beta (TGF-β) or receptor tyrosine kinase (RTK) ligands, which further...
5.6K
02:34Inhibition of Cdk Activity
4.8K
The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
4.8K
01:22MicroRNAs
3.0K
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
3.0K
01:15Drugs that Stabilize Microtubules
2.1K
Microtubules are dynamic structures that undergo cycles of catastrophe and rescue. The microtubules play a central role in cell division by forming the spindle apparatus for segregating the chromosomes. This makes them ideal targets for regulating dividing cells in tumors and malignant cancer cells. Microtubule stabilizing drugs help stabilize the microtubule formation and promote its polymerization. Paclitaxel was the first microtubule stabilizing agent used as anticancer drug in chemotherapy...
2.1K
02:53Adaptive Mechanisms in Cancer Cells
5.8K
Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer.
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
5.8K