Analysis of enhancement at small and large radiation doses for effectiveness of inactivation in cultured cells by combining two agents with radiation

Figures & data

Figure 1. Enhancement factor of the linear (α) and quadratic (β) parameters after combining radiation with a halogenated pyrimidine (BrdU, IdU or CldU) or hyperthermia and tri-modality treatment. R1 cells (A), RKO cells (B), α-enhancement for MOS, V79 and SW1573 cells (C). The value of 1 represents treatment with radiation alone. The values were derived from radiation dose survival curves with and without sensitizing agents. Each experiment was performed at least three times. Error bars are SD. *Significant difference from radiation only, **significant difference from duo-modality radiation and hyperthermia, ***significant difference from both duo-modalities. All p at least <0.05.

Figure 2. α-Enhancement factors for RUC-II cells (A) and β-enhancement factors for RUC-II cells (B) after combined radiation with a halogenated pyrimidine (BrdU, IdU or CldU) or hyperthermia and tri-modality treatment. The value of 1 represents treatment with radiation alone. The values were derived from radiation dose survival curves with and without sensitizing agents. Each experiment was performed at least three times. Error bars are SD. *Significant difference from radiation only, ***significant difference from both duo-modalities. All p at least <0.05.

Figure 3. Enhancement factor of the linear and quadratic parameters of SW1573 (A) and SIHA (B) cells after treatment with cisplatin, hyperthermia or combined treatment. The values were derived from radiation dose survival curves with and without sensitizing agents. The value of 1 represents treatment with radiation alone. Each experiment was performed at least three times. Error bars are SD. *Significant difference from radiation only, ***significant difference from both duo-modalities. All p at least <0.05.

Table 1. Values of the enhancement factor of the linear parameter alpha for the different sensitizing agents.

Cell line	Sensitizing agent	Enhancement factor RT + HT RT + agent RT + HT + agent			Figure
R1	HT 42	2.9 ± 0.5			1A
R1	CldU		3.4 ± 0.5	7.1 ± 0.5	1A
R1	BrdU		4.2 ± 0.6	6.5 ± 2.0	1A
R1	IdU		1.9 ± 0.2	4.2 ± 0.3	1A
RKO	HT 41	1.5 ± 0.15			1B
RKO	BrdU		1.5 ± 0.16	1.7 ± 0.16	1B
MOS	HT 42	4.0 ± 0.6			1C
MOS	IdU		1.8 ± 0.8	6.6 ± 1.4	1C
V79	HT 42	2.8 ± 0.3			1C
V79	IdU		1.8 ± 0.3	4.8 ± 0.7	1C
SW1573	HT 42	2.1 ± 0.2			1C
SW1573	IdU		4.3 ± 0.3	6.4 ± 0.4	1C
RUC-II	Ht 42	23.8 ± 0.9			1D
RUC-II	CldU		11.3 ± 10.1	50.0 ± 44.2	1D
RUC-II	BrdU		18.8 ± 16.6	81.3 ± 71.8	1D
RUC-II	IdU		7.5 ± 7.0	41.3 ± 36.4	1D
SW1573	HT 41	0.3 ± 0.1			2A
SW1573	Cispl 1μM		1.4 ± 0.2	1.8 ± 0.3	2A
SW1573	Cispl 5μM		1.7 ± 0.2	2.1 ± 0.8	2A
SW1573	HT 43	2.5 ± 0.3			2A
SW1573	Cispl 1μM		1.4 ± 0.2	3.8 ± 0.8	2A
SW1573	Cispl 5μM		1.7 ± 0.2	5.0 ± 0.9	2A
SIHA	HT41	1.8 ± 0.2			2B
SIHA	Cispl 1μM		3.5 ± 0.7	5.9 ± 1.0	2B

Values of the α-enhancement factors as also depicted in the figures for radiation combined with hyperthermia (HT41, HT42, HT43), halogenated pyrimidine (CldU, BrdU or IdU) or cisplatin (1 or 5μM only and for radiation combined with hyperthermia + halogenated pyrimidine as well as radiation combined with hyperthermia + cisplatin. Values ± SD.