LDR and its potential application in clinics

Transcription

1 LDR and its potential application in clinics Lu Cai Departments of Medicine & Radiation Oncology University it of Louisville School of Medicine

2 LDR effects Hormesis Adaptive response Bystander effects

3 LDR effects Hormesis Adaptive response Bystander effects

4 LDR Receptors Action G-CSF & other factors 9 hr BM progenitor cell proliferation 48 hr Mobilization PB hematopoietic progenitor cells 72 hr Bone marrow Peripheral Blood Time

5 LDR (75 mgy X- rays)/ 12 hr G-CSF at 3 μg/kg/day every 12 hr for three days 15 μg/kg/day G- CSF every 12 hours and then LDR once CFU-GM formation from peripheral mononuclear cells (A) C-kit + numbers in peripheral mononuclear cells (B)

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7 A a,b,c 14 Day 4 Day 7 12 Day 1 Day 13 Day = ± 3.52 a,b,c a a WBC, x 1 5 /ml LDR 15-G-CSF 3-G-CSF LDR/15-G-CSF Control B 1 C abc a,b,c a,b,c Anima al survival ra ate, % CFUs/ /spleen 25 a a Control LDR 15-G-CSF 3-G-CSF LDR/15-G-CSF Control LDR 15-G-CSF 3-G-CSF LDR/15-G-CSF

8 Table 1 Characteristics of different approaches to mobilize peripheral blood progenitor cells based on reviews (1,21) and the present study. Approaches Advantages Disadvantages Hematopoietic Efficient Expensive growth factors Bone painful such as G-CSF Headache Chemotherapy Efficient Expensive such as Toxic cyclophosphamide Combined above two Efficient Still expensive Toxic LDR and G-CSF Efficient Unknown yet Easier process Inexpensive Co-immunostimulation M ultiple factor stimulations Enhancing immune & hematology adaptive response Toxicities are not only the risk of hemorrhagic cystitis, fluid retention, and cardiomyopathy, but also the transient pancytopenia with infection of high dose chemotherapy drug such as cyclophosphamide (21).

9 Can we directly use LDR into clinics now? LDR may not only stimulate normal cell proliferation, but also stimulate the potent tumor cell proliferation or in situ tumor cell metastasis. LDR may not only enhance normal tissue resistance to subsequent radio- or chemo-therapy-induced side toxicity, but also make tumor cells become radio- or chemotherapy resistance (drug resistance).

10 Literature information Park et al. Cell Biol Toxicol. 15 (1999) A few mouse normal cell lines: lymphocytes y (NL), mouse connective tissue cells (L929) and primary mouse keratinocytes (PK) A few tumor cell lines: mouse papilloma (line 38) and mouse lymphoma cells (L5178Y-S and EL-4) Investigate the difference for LDR-induced adaptive response, as determined by cell survival and apoptosis. Adaptive response was induced by pretreatment with 1 mgy X- rays in normal cells such as NL, L929, and PK cell lines, but not in L5178Y-S, EL-4, and line 38 cells for cell survival rate. For reduction of apoptosis by pretreatment with LDR was also observed only in normal NL, L929, and PK cells, but not in tumor L5178Y-S, EL-4, and 38 cells.

11 Our question Whether or not LDR induces a same hormesis between normal and tumor cells? Cell proliferation Stimulation Adaptive response

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13 8 mgy 25mGy 6 5mGy 75mGy 4 1mGy 2mGy 1mGy 2 (HL-6) Times after radiation (days)

14 8 mgy (K562) 25mGy 6 5mGy 75mGy 4 1mGy 2mGy 2 1mGy

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16 numb bers, x 1 6 Cell NCI-H MRC BEL742 HL772 # 12 1 Times after radiation (days) # mgy 25 mgy 5 mgy 75 mgy mgy 6 1 mgy

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18 ers, x 1 6 numb Cell U T # HCT HLEPiC Times after radiation (days) #

19 In vitro studies using several human tumor cells indicate the absence of LDR-induced stimulation of cell proliferation

20 In vitro studies using several human tumor cells indicate the absence of LDR-induced stimulation of cell proliferation? In vitro = in vivo

21 Day Sham IP 75 mgy/post-d15 IP 75 mgy/post-d1 IP 75 mgy/pre-d IP 75 mgy/cells(6,,) ) IP 75 mgy/cells(1,,) IP

22 B Tumor-bearing C nude mouse model U251 tumor NCI-H446 tumor 4-6 days after implantation D Tumor weight, mg Tumor weig ght, mg 1.2 Control mgy NCI-H Control 75 mgy Days after 4. Gy X-rays U

23 Tu umor we eight, m 1.4 Sham 75 mgy/post-d mgy/post-d1 75 mgy/pre-d g75 mgy/cells(6,,) 1 75 mgy/cells(1,,) U Days after implantation of tumor cells

24 NCI-H446 ght, mg Tum mor wei Days after implantation of tumor cells

25 No hormesis in human tumor cells in response to LDR In vitro & in vivo

26 No hormesis in human tumor cells in response to LDR In vitro & in vivo Whether LDR induces same adaptive response between normal and tumor cells?

27 75 mgy (D1) - 12 hr - 1 Gy and then count cells at To otal cells, x 1 6 otal cells, x 1 6 T K562 p < 5f.5 for D2 or D1/D2 vs corresponding controls, A 6 HL-6 4 Control # D1 2 D2 D1/D p <.5 for D2 or D1/D2 vs corresponding controls, 6 NCI-H446 U251 MRC Days after 75 mgy or 1 mgy X-rays # # #

28 D1 + D2 When mice were killed on day 2 after D2 therapy, tumor inhibition (%) was calculated: tumor volumes in sham tumor volume in irradiated groups x 1 tumor volume in sham.

29 4 U # # # # Tumor inhibition, % NCI-H446 # Control D1 D2 D1/ 1/12h/D2 D1/ 1/24h/D2 D1/ 1/48h/D2 D1/ 1/72h/D2 5 Control D1 D2 D1/1 /12h/D 2 D1/2 /24h/D2 D1/4 /48h/D2 D1/7 /72h/D2 6 S18 5, #, #, # # Nude mice C57BL/6J Control D2 D1(5)/D2 D1(75)/D2 D1(1)/D2 Tumor inhibition, % Tumor inhibiti ion, %

30 A few in vivo studies Cheda A et al. Single low doses of X rays inhibit the development of experimental tumor metastases t and trigger the activities of NK cells in mice. Radiat Res. 161 (24) Anderson RE et al. Radiation-induced i d d augmentation ti of the response of A/J mice to SaI tumor cells. Am J Pathol. 18 (1982) Hashimoto S. et al. The suppression of metastases and the change in host immune response after low-dose total-body irradiation in tumor-bearing rats. Radiat Res. 151 (1999) Kojima S. et al. Elevation of glutathione induced by low-dose gamma rays and its involvement in increased natural killer activity. Radiat Res. 157 (22)

31 Whole-body LDR, given to tumor bearing mice before implantation of tumor cells, suppressed tumor growth rate (Cheda et al. 24; Anderson et al. 1982). Exposure of tumor-bearing mice to four doses of 25 mgy X- rays at day, 7, 14 and 21 after implantation of tumor cells significantly suppressed tumor cell growth (Hashimoto et al., 1999). A whole-body irradiation with 2 mgy, given at day 14 day after the implantation ti of allogenic hepatoma cells (KDH-8), significantly suppressed the incidence of lung and lymph node metastases (Kojima et al., 22). These results suggest the absence and even suppression of the tumor cell proliferation potency.

32 4 U # # # # Tumor inhibition, % NCI-H446 1 # Control D1 D2 D1/ 1/12h/D2 D1/ 1/24h/D2 D1/ 1/48h/D2 D1/ 1/72h/D2 5 Control D1 D2 D1/1 /12h/D 2 D1/2 /24h/D2 D1/4 /48h/D2 D1/7 /72h/D2 6 S18 5, #, #, # # Nude mice C57BL/6J Control D2 D1(5)/D2 D1(75)/D2 D1(1)/D2 Tumor inhibition, % Tumor inhibiti ion, %

33 HDR or chemotherapy do not affect tumor sensitivity to radiotherapy or chemotherapy LDR

34 LDR HDR or chemotherapy do not affect tumor sensitivity to radiotherapy or chemotherapy LDR-stimulated t immuno-function to eliminate the residual cells after radio- or chemokilled or after surgery

35 LDR HDR or chemotherapy AR: do not affect tumor sensitivity to radiotherapy or chemotherapy LDR-stimulated t immuno-function to eliminate the residual cells after radio- or chemokilled or after surgery protect the normal tissue from radiotherapy or chemotherapy Increase therapeutic dose

36 Acknowledgements Support by American Diabetes Association Juvenile Diabetes Research Foundation, International American Heart Association Philip Morris USA, Inc. Dr. Xuihua Sun Don Mosley Naira Metreveli Dr. Ye Song Dr. Jianxun Wang Collaboration Dr. Guanjun Wang Dr. Guangwei Liu Dr. Wei Li Dr. Xiaokun Li Dr. Y. James Kang Dr. Zhanxiang Zhou Dr. Yan Li Dr. Guihua Zhou Dr. Yuehui Wang Dr. Yunan Tang Dr. Yi Tan

37 Thank you!