TABLE 2.

GENE RESPONSES TO IONIZING RADIATION

	GADD45	CIP1	BAX	BCL-X	MCL1	GADD153	GADD34	c-JUN
Cell lines with normal p53 function
Apoptosis	+	+	+	+	+	+	+	+
No apoptosis	+	+	-	-	-	-	-	-
Cell lines with defective p53
Apoptosis*	-	-	-	-	+	+	+	+
No apoptosis	-	-	-	-	-	-	-	-

Induction, as measured by increased mRNA levels 4 h after IR, was determined in various human lines with wild-type or deficient p53 status and whether ionizing radiation induced a rapid apoptotic response as determined by filter elution (67-69,72,73), which detects high mw (approximately 50 kbp) DNA cleavage. The results were then separated into the four groups shown above. + indicates appreciable induction whereas — does not.

^* GADD45 and CIP1/WAF1 sometimes showed a weak response in a p53-deficient myeloid line (HL-60) undergoing apoptosis.