Dysregulated cell cycle

The cell cycle is a tightly regulated series of events controlling cell growth and division, ensuring cells replicate their DNA and divide accurately, producing two new daughter cells.

In healthy cells, this complex molecular machinery operates under strict control, allowing cells to respond appropriately to growth signals whilst maintaining genomic stability. However, in cancer cells, these regulatory mechanisms become disrupted, leading to uncontrolled proliferation and the accumulation of genetic errors.

CancerTools.org offers a diverse selection of antibodies specifically designed for cell cycle research. Our antibodies target key regulators and markers involved in cell cycle progression such as cyclins and Cyclin-Dependent Kinases (CDKs).

The cell cycle consists of two major phases: interphase and the mitotic phase. During interphase, cells grow and replicate DNA through three sequential sub-phases (G1, S and G2), before undergoing cell division in the mitotic phase.

G1 Phase:

• In the G1 phase, cells begin preparations for DNA synthesis
• Key regulators of this process include; Cyclin D/CDK4/6 complexes, Cyclin E/CDK2 complexes, P21, and Rb.
• The G1/S Restriction point checkpoint ensures DNA integrity before replication.

S Phase:

• In the S phase, DNA synthesis and chromosome replication occurs
• Key regulators of this process: Cyclin A/CDK2 and Proliferating cell nuclear antigen (PCNA)
• DNA damage check points monitor replication fidelity

G2 Phase:

• In the G2 phase, cells prepare for cell division
• Key regulators of this process include Cyclin A/CDK1
• The G2/M checkpoint ensures complete DNA replication, if failed, apoptosis or replication senescence occurs.

M Phase:

• In the M phase, mitosis and cell division occurs
• Key regulators of this process include Cyclin B/CDK1, CDC20, and CDC27
• The spindle assembly checkpoint ensures proper chromosome separation.

The cell cycle is driven by two major protein families working in concert: cyclins and cyclin-dependent kinases. Cyclins are regulatory proteins whose levels oscillate throughout the cell cycle. They function by binding to and activating their partner CDKs, which are protein kinases that drive cell cycle progression through the phosphorylation of key target proteins.

Each cyclin-CDK partnership functions as a specific molecular switch, triggering the events needed for cell cycle progression. The activity of these complexes is further regulated by inhibitory proteins, phosphorylation evens and protein degradation. Resulting in a sophisticated network of checks and balances that maintains orderly cell cycle progression.