Why does uncontrolled proliferation occur even with DNA damage when a growth factor receptor, such as EGFR, has a mutation inhibiting its internalization upon ligand binding?

💡 Explanation

The cell cycle checkpoints halt progression when DNA is damaged, but with a mutated growth factor receptor that cannot internalize, the downstream signaling needed to activate those checkpoints is disrupted; because the receptor remains active at the cell surface, it continually signals proliferation rather than allowing for DNA repair or apoptosis, therefore uncontrolled proliferation occurs, rather than cell cycle arrest or programmed cell death.

• Which outcome occurs when antithrombin III's activity is significantly reduced in blood plasma?
• If a patient's distal convoluted tubule and collecting duct are impermeable to water due to non-functional aquaporins, which consequence follows regarding plasma osmolality and ADH levels?
• Why does continuous consumption of highly salted potato chips eventually diminish perceived saltiness, even if salt concentration remains constant?
• A person recovering from opioid addiction experiences intense drug cravings when seeing old friends who still use. Why does this cue trigger craving?
• Why does a patient with impaired kidney function experience edema (swelling) as a result of reduced glomerular filtration?
• In a patient with hypertension resistant to multiple medications, what causes elevated blood pressure despite reduced angiotensin II levels after administration of an ACE inhibitor?