Cell cycle gene expression networks discovered using systems biology: Significance in carcinogenesis

Area of Science:

• Systems biology
• Genomics
• Cancer research

Background:

• Cell cycle checkpoints are crucial for regulating cell proliferation and differentiation.
• Defects in cell cycle control, particularly at the G1/S and mitotic spindle checkpoints, are implicated in carcinogenesis and chromosomal instability.

Purpose of the Study:

• To investigate the existence of co-varying cell cycle gene transcript networks in proliferative mammalian tissues.
• To identify networks associated with key cell cycle regulators like Cdc20 and Plk1.

Main Methods:

• Utilized systems biology approaches and analyzed gene expression datasets from the GeneNetwork website.
• Employed WebGestalt, a gene ontology tool, to identify co-varying gene expression networks.
• Examined tissues from mice, rats, and humans, including liver, lung, pituitary, adipose, and lymphoid tissues.

Main Results:

• Cell cycle expression networks composed of approximately 63 co-varying mRNA transcripts were identified in proliferative tissues (P = e(-13) to e(-36)).
• These networks were absent in non-proliferative tissues like brain and retina.
• Networks exhibited variability across species, sex, and tissue types, and were enriched in transcripts related to mitosis and chromosomal instability.

Conclusions:

• Co-varying cell cycle gene networks are a conserved feature of proliferative mammalian tissues.
• These networks are linked to mitotic processes and are associated with chromosomal instability, a hallmark of cancer.
• Findings provide insights into the molecular mechanisms underlying early carcinogenesis.