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Autologous marrow transplantation and the extracorporeal separability of normal and leukemic cells
Int. I Radiation Oncology Biol. Phys., Vol. 4. pp. 75L754 @ Pergamon Press Inc.. 1978. Printed in the U.S.A.
0
Letter to the Editor
AUTOLOGOUS MARROW TRANSPLANTATION AND THE EXTRACORPOREAL SEPARABILITY OF NORMAL AND LEUKEMIC CELLS THOMAS E. WHELDON Ph.D. West
of Scotland
Health
Boards,
Department of Clinical Physics & Bio-Engineering, Street, Glasgow G4 9LF, Scotland
11 West
Graham
and Institute
of Radiotherapeutics
and Oncology,
Western
Recently, Rubin” has emphasized that autologous bone marrow transplantation, used in conjunction with large-field radiotherapy or vigorous multi-agent chemotherapy, has considerable potential. ‘This procedure has the merit of disposing of problems of donor availability, graft rejection or graft-vs-host disease which arise when homologous (“non-self”) marrow is employed, but is potentially curative only when the infused marrow is free from malignant cells. In those diseases-notably leukemia-where marrow involvement is inevitable, attention has focussed on the use of homologous marrow transplantation, provided a suitable donor can be found. An exacting technique has provided encouraging results in the use of homologous marrow transplantation in acute leukemia;3,‘2.‘3 currently considerable effort is being devoted to improved methods of tissue typing and to methods of combating graft-vs-host disease where this occurs.” However, surprisingly little attention seems to have been given to a third possibility-the re-infusion of autologous marrow from which neoplastic cells have been eliminated extracorporeally. The attraction of this (as yet hypothetical) strategy arises from the possibility of using extracorporeal methods of selective cell kill which would be unacceptably dangerous while the marrow remained in vivo, and of being able to exploit biophysical differences between normal and neoplastic cells other than differential response to radiation or cytotoxic drugs. For example, normal and leukemic colony forming units (CFU’s) in chronic myeloid leukemia are reported*.9 to exhibit almost non-overlapping distributions of buoyant density. If these observations are confirmed, they may open the way to the extracorporeal separation of normal and leukemic stem cells using biophysical techniques. Again, normal and leukemic lymphocytes exhibit markedly different volume responses to osmotic shock.’ If this differential reflects differences at the stem cell level, then this method too might be developed as a means of separating normal from leukemic stem cells. Normal and
Infirmary,
Dumbarton
Road, Glasgow
G 11, Scotland
leukemic cells also exhibit differential recovery after different patterns of freezing and thawing;’ patterns might be found which facilitate preferential recovery of normal cells. A particularly interesting possibility arises from the reported differential heat sensitivity of normal and malignant cells.c7 Unfortunately, favorable differentials usually are found only in a narrow temperature range of 42-45°C; this is an excess of tolerable body core temperatures, and reduces the prospects for whole-body hyperthermia as a curative procedure in disseminated disease. calculations based on reported thermal However, survival curves of normal and leukemic (L1210) stem cells in the mouseI yield promising estimates for the separation of normal and leukemic stem cells by extracorporeal heating. These calculations’4 suggest that to each l-log kill (i.e. 10-l survival) of normal cells by incubation at 42”C, there corresponds a 4-log kill (10m4 survival) of L1210 leukemia cells. Now, if these murine data are relevant to the human situation, if up to lo9 human marrow cells/kg may be accumulated in leukemic remission by multiple aspiration,3.‘2.‘3 and if Rubin”’ is correct in asserting that lO’cells/kg is adequate for successful autografting, then a 2-log normal cell kill could be tolerated giving an 8-log kill of leukemic cells. Although such calculations are naive, they serve to indicate the theoretical possibility of selective elimination of quite large numbers of leukemic cells by extracorporeal hyperthermia. Moreover, this could be carried out using very simple apparatus (e.g. a water bath). Similar considerations may apply to other neoplastic diseases (lymphoma, myeloma, etc.) where marrow involvement is likely or inevitable. More generally, the advent of autologous marrow transplantation opens the way to exploitation of a wider class of cellular differences between normal and malignant cells than are therapeutically useful at present. This strategy perhaps deserves increased attention.
REFERENCES Ben-Sasson, S., Shaviv, R., Bentwich, Z., Slavin, S., Doljanski, F.: Osmotic behaviour of normal and leukaemic lymphocytes. Hood 46: 891-900, 1975.
2. Farrant, Selection thawing. 753
J., Knight, S.C., O’Brien, J.A., Morris, G.I.: of leukaemic cell populations by freezing and Nature 245: 322-323, 1973.
754
Radiation
Oncology
0 Biology
0 Physics
3. Gale, R.P., Feig, S., Opelz, G., Territo, M., Young, L., Fahey, S.G., Cline, M.J. and the U.C.L.A. Bone Marrow Transplant Team.: Bone marrow transplantation in acute leukaemia using intensive chemoradiotherapy (SCARI-UCLA). Transplant. Proc. 8: 611-616, 1976. 4. Giovanelli, B.C., Morgan, A.C., Stehlin, J.S., Williams, L.J.: Selective lethal effect of supranormal temperatures on mouse sarcoma cells. Cancer Res. 33: 256% 2578, 1973. 5. Kase, K., Hahn, B.M.: Differential heat response of normal and transformed human cells in tissue culture. Nature 255: 228-230, 1975. 6. Kase, K., Hahn, B.M.: Comparison of some response to hyperthermia by normal human diploid cells and neoplastic cells from the same origin. Europ. J. Cancer 12: 481-492, 1976. 7. Kim, J.H., Kim, S.H., Hahn, E.W.: Thermal enhancement of radiosensitivity using cultured normal and neoplastic cells. Am. J. Roentgenol. 121: 860-864, 1974. 8. Metcalf, D.: The discrimination of leukaemic from normal cells. Biomedicine 18: 264-271, 1973. 9. Moore, M.A.S., Williams, N. and Metcalf, D.: Characterization of in vitro colony forming cells in acute and
July-August
10. 11.
12.
13.
14.
1978, Volume
4, No. 7 and No. 8
chronic myeloid leukaemia. In The Nature of Leukaemia, ed. by Vincent, P.C. Australian Cancer Society, Sydney, 1972, pp. 135-145. Int. J. Radiat. Rubin, P.: Bone marrow autografting. One. Biol. Phys. 2: 213-214, 1977. Storb, R., Gluckman, E., Thomas, E.D., Buckner, C.D., Clift, R.A., Fefer, A., Glucksberg, H., Graham, T.C., Johnson, F. L., Lerner, K.G., Nieman, P.E., Ochs, H.: Treatment of established human graft-vs-host disease by antithymocyte globulin. Blood 44: 57-75, 1974. Thomas, E.D., Buckner, C.D., Banaji, M., Clift, R.A., Fefer, A., Flournoy, N., Goodell, B.W., Hickman, R.O., Lerner, K.G., Neiman, P.E., Sale, G.E., Sanders, J.E., Singer, J., Steven, M., Starb, R., Weiden, P.L.: One hundred patients with acute leukaemia treated by chemotherapy, total body irradiation and allogeneic marrow transplantation. Blood 49: 511-533, 1977. Thomas, E.D., Fefer, A., Buckner, C.D., Storb, R.: Current status of bone marrow transplantation for aplastic anemia and acute leukaemia. Blood 49: 671681, 1977. Wheldon, T.E.: Exploiting heat sensitivity of leukaemic cells. Lancet ii: 1363-1364, 1976.
0
Letter to the Editor
AUTOLOGOUS MARROW TRANSPLANTATION AND THE EXTRACORPOREAL SEPARABILITY OF NORMAL AND LEUKEMIC CELLS THOMAS E. WHELDON Ph.D. West
of Scotland
Health
Boards,
Department of Clinical Physics & Bio-Engineering, Street, Glasgow G4 9LF, Scotland
11 West
Graham
and Institute
of Radiotherapeutics
and Oncology,
Western
Recently, Rubin” has emphasized that autologous bone marrow transplantation, used in conjunction with large-field radiotherapy or vigorous multi-agent chemotherapy, has considerable potential. ‘This procedure has the merit of disposing of problems of donor availability, graft rejection or graft-vs-host disease which arise when homologous (“non-self”) marrow is employed, but is potentially curative only when the infused marrow is free from malignant cells. In those diseases-notably leukemia-where marrow involvement is inevitable, attention has focussed on the use of homologous marrow transplantation, provided a suitable donor can be found. An exacting technique has provided encouraging results in the use of homologous marrow transplantation in acute leukemia;3,‘2.‘3 currently considerable effort is being devoted to improved methods of tissue typing and to methods of combating graft-vs-host disease where this occurs.” However, surprisingly little attention seems to have been given to a third possibility-the re-infusion of autologous marrow from which neoplastic cells have been eliminated extracorporeally. The attraction of this (as yet hypothetical) strategy arises from the possibility of using extracorporeal methods of selective cell kill which would be unacceptably dangerous while the marrow remained in vivo, and of being able to exploit biophysical differences between normal and neoplastic cells other than differential response to radiation or cytotoxic drugs. For example, normal and leukemic colony forming units (CFU’s) in chronic myeloid leukemia are reported*.9 to exhibit almost non-overlapping distributions of buoyant density. If these observations are confirmed, they may open the way to the extracorporeal separation of normal and leukemic stem cells using biophysical techniques. Again, normal and leukemic lymphocytes exhibit markedly different volume responses to osmotic shock.’ If this differential reflects differences at the stem cell level, then this method too might be developed as a means of separating normal from leukemic stem cells. Normal and
Infirmary,
Dumbarton
Road, Glasgow
G 11, Scotland
leukemic cells also exhibit differential recovery after different patterns of freezing and thawing;’ patterns might be found which facilitate preferential recovery of normal cells. A particularly interesting possibility arises from the reported differential heat sensitivity of normal and malignant cells.c7 Unfortunately, favorable differentials usually are found only in a narrow temperature range of 42-45°C; this is an excess of tolerable body core temperatures, and reduces the prospects for whole-body hyperthermia as a curative procedure in disseminated disease. calculations based on reported thermal However, survival curves of normal and leukemic (L1210) stem cells in the mouseI yield promising estimates for the separation of normal and leukemic stem cells by extracorporeal heating. These calculations’4 suggest that to each l-log kill (i.e. 10-l survival) of normal cells by incubation at 42”C, there corresponds a 4-log kill (10m4 survival) of L1210 leukemia cells. Now, if these murine data are relevant to the human situation, if up to lo9 human marrow cells/kg may be accumulated in leukemic remission by multiple aspiration,3.‘2.‘3 and if Rubin”’ is correct in asserting that lO’cells/kg is adequate for successful autografting, then a 2-log normal cell kill could be tolerated giving an 8-log kill of leukemic cells. Although such calculations are naive, they serve to indicate the theoretical possibility of selective elimination of quite large numbers of leukemic cells by extracorporeal hyperthermia. Moreover, this could be carried out using very simple apparatus (e.g. a water bath). Similar considerations may apply to other neoplastic diseases (lymphoma, myeloma, etc.) where marrow involvement is likely or inevitable. More generally, the advent of autologous marrow transplantation opens the way to exploitation of a wider class of cellular differences between normal and malignant cells than are therapeutically useful at present. This strategy perhaps deserves increased attention.
REFERENCES Ben-Sasson, S., Shaviv, R., Bentwich, Z., Slavin, S., Doljanski, F.: Osmotic behaviour of normal and leukaemic lymphocytes. Hood 46: 891-900, 1975.
2. Farrant, Selection thawing. 753
J., Knight, S.C., O’Brien, J.A., Morris, G.I.: of leukaemic cell populations by freezing and Nature 245: 322-323, 1973.
754
Radiation
Oncology
0 Biology
0 Physics
3. Gale, R.P., Feig, S., Opelz, G., Territo, M., Young, L., Fahey, S.G., Cline, M.J. and the U.C.L.A. Bone Marrow Transplant Team.: Bone marrow transplantation in acute leukaemia using intensive chemoradiotherapy (SCARI-UCLA). Transplant. Proc. 8: 611-616, 1976. 4. Giovanelli, B.C., Morgan, A.C., Stehlin, J.S., Williams, L.J.: Selective lethal effect of supranormal temperatures on mouse sarcoma cells. Cancer Res. 33: 256% 2578, 1973. 5. Kase, K., Hahn, B.M.: Differential heat response of normal and transformed human cells in tissue culture. Nature 255: 228-230, 1975. 6. Kase, K., Hahn, B.M.: Comparison of some response to hyperthermia by normal human diploid cells and neoplastic cells from the same origin. Europ. J. Cancer 12: 481-492, 1976. 7. Kim, J.H., Kim, S.H., Hahn, E.W.: Thermal enhancement of radiosensitivity using cultured normal and neoplastic cells. Am. J. Roentgenol. 121: 860-864, 1974. 8. Metcalf, D.: The discrimination of leukaemic from normal cells. Biomedicine 18: 264-271, 1973. 9. Moore, M.A.S., Williams, N. and Metcalf, D.: Characterization of in vitro colony forming cells in acute and
July-August
10. 11.
12.
13.
14.
1978, Volume
4, No. 7 and No. 8
chronic myeloid leukaemia. In The Nature of Leukaemia, ed. by Vincent, P.C. Australian Cancer Society, Sydney, 1972, pp. 135-145. Int. J. Radiat. Rubin, P.: Bone marrow autografting. One. Biol. Phys. 2: 213-214, 1977. Storb, R., Gluckman, E., Thomas, E.D., Buckner, C.D., Clift, R.A., Fefer, A., Glucksberg, H., Graham, T.C., Johnson, F. L., Lerner, K.G., Nieman, P.E., Ochs, H.: Treatment of established human graft-vs-host disease by antithymocyte globulin. Blood 44: 57-75, 1974. Thomas, E.D., Buckner, C.D., Banaji, M., Clift, R.A., Fefer, A., Flournoy, N., Goodell, B.W., Hickman, R.O., Lerner, K.G., Neiman, P.E., Sale, G.E., Sanders, J.E., Singer, J., Steven, M., Starb, R., Weiden, P.L.: One hundred patients with acute leukaemia treated by chemotherapy, total body irradiation and allogeneic marrow transplantation. Blood 49: 511-533, 1977. Thomas, E.D., Fefer, A., Buckner, C.D., Storb, R.: Current status of bone marrow transplantation for aplastic anemia and acute leukaemia. Blood 49: 671681, 1977. Wheldon, T.E.: Exploiting heat sensitivity of leukaemic cells. Lancet ii: 1363-1364, 1976.