Final answer:
Cancer cells use methods like increased proliferation, avoidance of programmed cell death, DNA repair activation, and immune system evasion as survival strategies. Resistance to apoptosis and active telomerase are key factors in their unchecked growth. Treatments aim to disrupt these processes to eliminate cancerous growth.
Step-by-step explanation:
Cancer cells employ several mechanisms to ensure their survival, such as increased cell division and growth, inhibition of apoptosis, activation of DNA repair mechanisms, and evasion of the immune system. Malignant cells can become resistant to induction of apoptosis, enabling them to proliferate unchecked. These cells can suppress the immune system by expressing proteins that turn off cytotoxic T cells or induce regulatory T cells to dampen immune responses. Additionally, cancer cells with shortened telomeres may activate telomerase to continue dividing, thus evading normal cellular aging processes that would limit division.
Cancer therapy strategies often focus on disrupting these survival mechanisms, such as inhibiting telomerase or enhancing the body's immune response to target cancer cells. The study of cancer cells and the cell cycle reveals a breakdown in the regulatory systems that control normal cell division, where genetic mutations and faulty proteins result in unregulated growth leading to tumors or leukemia.