J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website http://www.jocmr.org

Original Article

Volume 10, Number 11, November 2018, pages 815-821

The Effect of p53 Status on Radio-Sensitivity of Quiescent Tumor Cell Population Irradiated With γ-Rays at Various Dose Rates

Figure 1. Surviving fractions following γ-ray irradiation. The clonogenic cell survival curves for total tumor cell populations immediately and 9 h after γ-ray irradiation with high dose-rate irradiation (HDR) and immediately after γ-ray irradiation with middle dose-rate irradiation (MDR) and low dose-rate irradiation (LDR) are shown. The left and right panels show SAS/neo and SAS/mp53 tumor cells, respectively. Bars represent standard errors (n = 6).

Figure 2. Net micronucleus frequencies following γ-ray irradiation. The net micronucleus frequencies for total (solid lines, open symbols) and quiescent (dotted lines, solid symbols) cell populations immediately and 9 h after γ-ray irradiation with high dose-rate irradiation (HDR) and immediately after γ-ray irradiation with middle dose-rate irradiation (MDR) and low dose-rate irradiation (LDR) are shown. The left and right panels show SAS/neo and SAS/mp53 tumor cells, respectively. Bars represent standard errors (n = 6).

**Table 1.** Plating Efficiency and Micronucleus Frequency at 0 Gy
	Total tumor cells	Quiescent cells
^aMean ± standard error (n = 6).
SAS/neo
Plating efficiency (%)	45.5 ± 8.9^a
Micronucleus frequency	0.038 ± 0.006	0.056 ± 0.007
SAS/mp53
Plating efficiency (%)	23.5 ± 4.1
Micronucleus frequency	0.072 ± 0.008	0.111 ± 0.010

Table 1. Plating Efficiency and Micronucleus Frequency at 0 Gy

Total tumor cells

Quiescent cells

^aMean ± standard error (n = 6).

SAS/neo

Plating efficiency (%)

45.5 ± 8.9^a

Micronucleus frequency

0.038 ± 0.006

0.056 ± 0.007

SAS/mp53

Plating efficiency (%)

23.5 ± 4.1

Micronucleus frequency

0.072 ± 0.008

0.111 ± 0.010

**Table 2.** Dose-Modifying Factors Due to a Delayed Assay or Reduced Irradiation Dose Rate^a
	HDR	MDR	LDR
^aThe ratio of the dose of radiation necessary to obtain each end-point with a delayed assay or reduced dose-rate irradiation to that needed to obtain each end-point with an assay immediately after high dose-rate irradiation. ^bMean ± standard error (n = 6).
Surviving fraction = 0.2
SAS/neo	1.5 ± 0.15^b	1.6 ± 0.15	2.1 ± 0.2
SAS/mp53	1.1 ± 0.1	1.2 ± 0.1	1.3 ± 0.1
Net micronucleus frequency = 0.1
Total tumor cells
SAS/neo	1.4 ± 0.1	1.45 ± 0.1	1.8 ± 0.15
SAS/mp53	1.05 ± 0.1	1.1 ± 0.1	1.15 ± 0.1
Quiescent cells
SAS/neo	1.55 ± 0.15	1.65 ± 0.15	1.85 ± 0.2
SAS/mp53	1.05 ± 0.1	1.1 ± 0.1	1.2 ± 0.1

Table 2. Dose-Modifying Factors Due to a Delayed Assay or Reduced Irradiation Dose Rate^a

HDR

MDR

LDR

9h later

^aThe ratio of the dose of radiation necessary to obtain each end-point with a delayed assay or reduced dose-rate irradiation to that needed to obtain each end-point with an assay immediately after high dose-rate irradiation. ^bMean ± standard error (n = 6).

Surviving fraction = 0.2

SAS/neo

1.5 ± 0.15^b

1.6 ± 0.15

2.1 ± 0.2

SAS/mp53

1.1 ± 0.1

1.2 ± 0.1

1.3 ± 0.1

Net micronucleus frequency = 0.1

Total tumor cells

SAS/neo

1.4 ± 0.1

1.45 ± 0.1

1.8 ± 0.15

SAS/mp53

1.05 ± 0.1

1.1 ± 0.1

1.15 ± 0.1

Quiescent cells

SAS/neo

1.55 ± 0.15

1.65 ± 0.15

1.85 ± 0.2

SAS/mp53

1.05 ± 0.1

1.1 ± 0.1

1.2 ± 0.1

**Table 3.** Dose-Modifying Factors for SAS/*mp53* Relative to SAS/*neo* Tumor Cells^a
HDR	HDR	MDR	LDR
^aThe ratio of the physical radiation dose of external beams necessary to obtain each end-point in SAS/mp53 tumor cells to that needed to obtain each end-point in SAS/neo tumor cells. ^bMean ± standard error (n = 6).
Surviving fraction = 0.2
1.4 ± 0.1^b	1.05 ± 0.1	1.05 ± 0.1	1.0 ± 0.1

Table 3. Dose-Modifying Factors for SAS/mp53 Relative to SAS/neo Tumor Cells^a

HDR

MDR

LDR

Right after

9 h later

^aThe ratio of the physical radiation dose of external beams necessary to obtain each end-point in SAS/mp53 tumor cells to that needed to obtain each end-point in SAS/neo tumor cells. ^bMean ± standard error (n = 6).

Surviving fraction = 0.2

1.4 ± 0.1^b

1.05 ± 0.1

1.0 ± 0.1

**Table 4.** Dose-Modifying Factors for Quiescent Relative to Total Tumor Cells^a at Net Micronucleus Frequency of 0.1
HDR	HDR	MDR	LDR
^aThe ratio of the dose of radiation necessary to obtain each end-point in the quiescent cell population to that needed to obtain each end-point in the total tumor cell population. ^bMean ± standard error (n = 6).
SAS/neo
2.2 ± 0.2^b	2.2 ± 0.2	2.4 ± 0.25	2.45 ± 0.25
SAS/mp53
1.85 ± 0.2	1.9 ± 0.2	1.9 ± 0.2	1.95 ± 0.2

Table 4. Dose-Modifying Factors for Quiescent Relative to Total Tumor Cells^a at Net Micronucleus Frequency of 0.1

HDR

MDR

LDR

Right after

9 h later

^aThe ratio of the dose of radiation necessary to obtain each end-point in the quiescent cell population to that needed to obtain each end-point in the total tumor cell population. ^bMean ± standard error (n = 6).

SAS/neo

2.2 ± 0.2^b

2.2 ± 0.2

2.4 ± 0.25

2.45 ± 0.25

SAS/mp53

1.85 ± 0.2

1.9 ± 0.2

1.95 ± 0.2