The Conditions of Non-rescuability of Methioninase-treated Cancer Cells by Methionine Replenishment: The Point of No Return

Three distinct responses to methionine replenishment following rMETase treatment were observed in HCT-116 cells. First, complete recovery and resumption of proliferation occurred with low-dose rMETase at all time points and with short-term treatment at intermediate doses of r-METase. Second, prolonged intermediate-dose treatment or short-term high-dose treatment, resulted in continued proliferation arrest without further cell death. Third, high-dose rMETase treatment for six days led to cell death.