Association of in Vitro Radiosensitivity and - Cancer Research

[CANCER RESEARCH 41, 2046-2050, June 1981]0008-5472/81 /0041-OOOOS02.00

Association of in Vitro Radiosensitivity and Cancer in a Family withAcute Myelogenous Leukemia1

N. Torben Bech-Hansen,2 Brenda M. Sell, John J. Mulvihill, and Malcolm C. Paterson

Health Sciences Division. Atomic Energy of Canada Limited, Chalk River, Ontario KOJ ÕJO, Canada ¡N.T. B-H., B. M. S., M. C. P.], and Clinical Epidemiology

Branch, National Cancer Institute, NIH, Bethesda, Maryland 20205 [J. J. M.]

ABSTRACT

The y-ray sensitivity of skin fibroblasts from six members ofa cancer family was investigated using a colony-forming assay.

Fibroblasts from the three members with cancer (two sisterswith acute myelogenous leukemia and the mother with cervicalcarcinoma) showed a significant (p < 0.05) increase in radi-

osensitivity, while three members without cancer (the fatherand two sons) showed a normal radioresponse. The possibilitythat the increased y-ray sensitivity was due to defective DMA

repair was investigated using assays for DNA repair replication,single-strand break rejoining, and removal of enzyme-sensitivesites in y-irradiated DNA. Results of these assays indicate thatthe kinetics of enzymatic repair of radiogenic DNA damage ingeneral, and the rejoining of single-strand scissions and exci

sion repair of base and sugar radioproducts in particular, werethe same in the cell lines from the sensitive and clinically normalfamily members.

INTRODUCTION

The excessive occurrence of cancer is a feature of over 200different human single-gene diseases (18), including thosewhich exhibit chromosomal instability and radiation sensitivity(9, 20). Striking in vitro radiosensitivity has been a feature ofall skin fibroblasts and lymphoblast cultures assayed fromindividuals with the cancer-prone disorder AT3 (21, 32). In

addition, fibroblasts or lymphoblasts from individuals with anyof several other genetic disorders that show cancer proneness,neurodegeneration, or both features frequently display significant increases in radiosensitivity: e.g., hereditary retinoblas-toma (33); Friedreich's ataxia (10); Huntington's disease (1,

16, 21 ); and tuberous sclerosis (3). Extensive surveys for suchradiosensitivity in numerous human cell lines were presentedrecently (2, 21, 26, 34).

Additional evidence that an individual's genetic constitution

can play a significant role in the development of neoplasmscomes from the clustering of cancers in some families (6, 8,11). Since ionizing radiation is known to be leukemogenic (14,15), we were prompted to investigate whether the host factor,which segregated in one AML family described previously (12,13, 31 ), conferred an altered susceptibility to an environmentalagent such as radiation. This report describes our assessment

' Supported in part by Contract NO1 -CP-81002 with the Clinical Epidemiology

Branch. National Cancer Institute. NIH. Bethesda, Md.2 To whom requests for reprints should be addressed.3 The abbreviations used are: AT. ataxia telangiectasia; AML, acute myelog

enous leukemia; BrdUrd, bromodeoxyuridine; FdUrd, fluorodeoxyuridine; dThd,thymidine; D,0, dose in rads reducing survival to 10%; D0, dose in rads reducingsurvival by 63% in the exponential region (i.e.. inverse of the slope of exponentialregion).

Received October 16, 1980; accepted February 18, 1981.

of the 60Co y-ray sensitivity and DNA repair capacity of fibro-

blast cells from the available members of this family [bothparents and 4 of their 6 children including the proband (Chart1)].

MATERIALS AND METHODS

Cell Lines. GM 38, GM 43, and WI38 from clinically normalindividuals were obtained from the Institute for Medical Research, Camden, N. J., and AT2BE (CRL 1343), a radiosensitive strain from a patient with AT (22, 25), was obtained fromthe American Type Culture Collection, Rockville, Md. Culturesfrom the 6 members of the AML cancer family (cf. Chart 1) and1461T and 3151T from clinically normal individuals were supplied by Meloy Laboratories, Springfield, Va. All fibroblastswere grown as monolayer cultures in Ham's F-12 medium (7)

fortified with 15% (v/v) heat-inactivated fetal calf serum, 1 ITIM

glutamine, penicillin (100 lU/ml), and streptomycin (100 IU/ml), and incubated at 37°in humidified 5% CO2 in air. Culture

supplies were purchased from Microbiological Associates, Inc.,Walkersville, Md. or Grand Island Biological Co., Burlington,Ontario, Canada. All cultures were routinely checked for My-

coplasma contamination by the Hoechst staining method (4)and a double-label method measuring the incorporation of [6-3H]uracil and [L/-'"C]uridine (28, 29). These radioactive com

pounds were obtained from New England Nuclear, Lachine,Quebec, Canada.

y-Ray Sensitivity. To measure the radiosensitivity of the skinfibroblast cultures, samples of cells in suspension (1 to 2 X105/ml) were exposed at 4°to graded doses of ^Co y-rays

from a Gammabeam 150c (Atomic Energy of Canada Limited,Ottawa, Ontario, Canada) at a dose rate of 70 to 76 rads/min.Feeder cells (5) were exposed at 4° to 60Co y-radiation (5

kilorads) in a Gammacell 220 (Atomic Energy of Canada Limited) at a dose rate of 15.9 to 17.7 kilorads/min prior toseeding with experimental cells to give 6 to 8 x 104 total cells/

100-mm-diameter tissue culture plate. Experimental cultureswere incubated for 18 to 24 days with twice-weekly changes

of medium before fixing the resulting colonies 5 to 10 min withBouin's fixative (27) and staining 5 min with a 0.04% (w/v)

aqueous solution of crystal violet (Fisher Scientific Co., Missis-

sauga, Ontario, Canada). Colonies composed of 100 or morecells were enumerated.

y-Ray-induced DNA Repair Replication. This parameter ofDNA repair is used as a gross measure of the repair activity indamaged DNA. The labeling regime was designed to allow theincorporation of exogenous nucleotides into DNA during therepair of radioproducts while inhibiting de novo DNA synthesis.Unlabeled cultures of 2 to 4 x 106 attached cells were (a)

incubated for 2 hr in F-12 medium (supplemented with 10%dialyzed fetal calf serum) containing 6.5 ¡IMBrdUrd and 1 JUM

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Radiosensitivity in AML Cancer Family

FdUrd, rinsed, and covered with Hanks' balanced salt solution;

(b) y-irradiated in a Gammacell 220 either with (hypoxia) or

without (oxia) nitrogen (99.98% pure, <10 ppm O2; Air Products, Brampton, Ontario, Canada), flushing (15 min) prior toand during irradiation; (c) then incubated for 2 hr with 10 juCi[mefr)y/-3H]dThd per ml [specific activity, 50 to 55 Ci/mmol;

Amersham/Searle, Oakville, Ontario, Canada or New EnglandNuclear (Canada)] in F-12 medium containing 6.5 JUMBrdUrd,

1 fiM FdUrd, and 1 ITIMhydroxyurea; and finally (d) incubatedfor 1 hr in F-12 medium containing 6.5 fiM BrdUrd and 1 ¡J.M

FdUrd. Hydroxyurea, BrdUrd, and FdUrd were purchased fromCalbiochem-Behring Corp., La Jolla, Calif. The extent of repair

C MALE WITH ACUTE MYELOGENOUS LEUKEMIA

3 FEMALE WITH OTHER MALIGNANCY<4-b TRIPLET SPONTANEOUS ABORTION

/ PROBAND

Chart 1. National Cancer Institute Family 375: the mother (2649T) developedrectal carcinoma 17 years after carcinoma of the uterine cervix (diagnosed atage 28) was treated with radiotherapy. Four of her children died of AML; the ageat the time of diagnosis was 2, 6, 21, and 11 years, respectively. Three other ofher relatives had AML, and 2 of her nephews developed malignant recticuloen-dotheliosis (31). In addition, 2 maternal siblings have recently developed breastand colon cancer. The present age of the father is 49 years while the male twinsare 20 years old; all 3 males are still clinically normal.

replication occurring during the 2-hr postirradiation labeling

period was determined by equilibrium centrifugation of theradioactive and density-labeled DNA in Nal gradients as de

scribed previously (22). The magnitude of repair replicationhas been expressed as dpm per /¿gDNA based on the six 300-jul-peak fractions.

Enzymatic Assay. The number of strand breaks and basedefects in y-ray-damaged DNA was assessed using a methoddescribed previously (22, 23). In brief, [3H]dThd-labeled, y-

irradiated (50 kilorads, N?) cultures were incubated for up to 2hr at 37° and lysed, and their DNA's were coextracted withlysed [14C]dThd-labeled unirradiated cells of the same subcultures. The various DNA samples were incubated at 37°with or

without a Micrococcus luteus protein extract containing strand-

incising activity (endonucleases and DNA glycosylases) towardy-ray-induced DNA sites. The number of single-strand breaksand extract-sensitive sites was determined by velocity centrif

ugation in alkaline sucrose gradients.

RESULTS

Fibroblast survival was monitored after y-irradiation. Theresults of colony-forming assays after oxic y-irradiation for a

normal control (GM 38), a sensitive control (AT2BE), and the6 experimental cell strains are presented in Chart 2. Theparameters for these oxic y-ray survival curves are summarized

in Table 1. In comparing the survival curves (Chart 2a) and theD10 values (Table 1), fibroblasts from the 3 clinically normalmembers of the family (2650T from the father and 2647T and2648T from the dizygotic male twins), it is apparent that theirradiosensitivity is similar to that of the clinically normal strainstested during the period of this study. Fibroblasts from themother (2649T) and the leukemic daughters (409T and 2642T)

I.OOO —r—r

STRAIND GM 38x AT2BE»2647To 2648T

»2650T

O.OOI200 400 600 800 0 200 400 600 800

I •1000

DOSE (rods)

Fig. 2. Colony-forming ability after 60Co y-irradiation in air of fibroblast strains from normal (a) and cancer-affected individuals (b) in each case including a normal

and a radiosensitive control. Shaded areas, range in the survival response of the 5 normal strains listed in Table 1 (i.e., area bounded by the mean survival curves forGM 43 and 1461T). The exponential portion of the survival curves was determined by linear regression analysis.

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N. T. Bech-Hansen et al.

Table 1Parameters (calculated for each strain by least-squares linear regression analysis of pooled data) of oxic

y-ray survival curves for fibroblast strains from members of AML family

StrainControl0GM38WI38GM431461T3151TClinicalde

scriptionNormalsNormalNormalNormalNormalNormalNo.

ofexperi

ments1961264Passagerange87-2913-232911,

1513-187,

12PE

(%)30±7d33

±173523

±221±736±14nb2.0

±0.52.2

±0.61.8±0.61.1±0.12.5±0.72.2±0.4Do138

±13132

±9142±12158±6130±8126± 5D,o402

±15407

±15411±19382±9417±17391±10

AT2BE AT 13-17 6± 0 1.0 ±0.3 73 ± 5e 169 ± 9e

2649T2650T409T2642T264

7T2648TCarcinomaNormalAMLAMLNormalNormal45642410-188-2311-2412-1511-159-2017

±1445±1425±79±237±137± 91.3

±0.22.3±0.71.6±0.30.6±0.2'3.8

±2.41.9±0.3117

±5136 ±11129

±6168 ±17114

±14136± 6301

±1e425

±19360±13e290±31e41

7 ±30400±10

a Number of times strains were subcultured (1:2 dilutions) before use in survival experiments.0 PE, plating efficiency; n, intercept on the ordinate obtained by extrapolation of exponential region of

the curve.c Average survival response of the 5 normal control strains based on least-squares linear regression

analysis of pooled survival.''Mean ±S.E.e Instances where D,0 or D0 values for the experimental strain and the normal controls (mean values or

GM38) differed significantly (p < 0.05). The radiosensitivity of a strain was compared to that for normalcontrols using the standard error of difference test (17).

' The small intercept (n) value for 2642T was characteristic of this culture ¡neach of the 4 experiments

and may possibly represent the presence of 2 subpopulations, one more sensitive than the other; thebiphasic nature of the survival curves was absent in experiments with hypoxic irradiation (Table 2).

were significantly more sensitive based on their D,0 values thanthe mean D10value for the normals, though clearly much lesssensitive than an AT homozygote (AT2BE) (Table 1; Chart 2).The differences in the survival response of the 3 strains fromthe females in the family presumably reflect inherent differences of the strains. The decrease in Di0 values after oxicirradiation reflects a reduced shoulder region in the survivalcurves without a significant change in the D0's. This can be

interpreted as the reduced capacity of cell strains to accumulate sublethal damage in their DMA. The D,0 parameter responds to both changes in the survival curve shoulder andchanges in the exponential part of the curve (from which a D0value is determined) and can therefore be a more sensitiveparameter than D0 for assessing the radiosensitivity of a givenhuman skin fibroblast strain.

The oxic survival data showed complete concordance between the development of cancer in family members and adecrease in Dio values for the corresponding fibroblast strains;as well, fibroblasts from each of the clinically normal familymembers showed normal in vitro sensitivity. Further confirmation of the increased y-ray sensitivity in strains from individualswith cancer (409T, 2642T, and 2649T) was found by irradiatingunder hypoxic conditions, previously used to detect AT hétérozygotes (24). From the D10values, each of the 3 strains againshowed increased radiosensitivity when compared to strainsGM 38 and 2650T (Table 2; Chart 3). The survival curves forthe 2 strains 2649T and 409T also showed significantly lowerDo values under the hypoxic conditions.

Knowledge of defective DNA repair in xeroderma pigmento-sum and AT (20) prompted us to investigate whether the strainswhich displayed increased radiosensitivity and which derivedfrom cancer-bearing individuals in this family had impaired

Table 2Parameters of hypoxic y-ray survival curves

Cells from monolayer cultures were handled as for the oxic -y-ray survivalexperiments (see "Materials and Methods") except that cell suspensions were

flushed with nitrogen for 15 min immediately prior to and during the irradiation.Parameters and abbreviations are defined in Table 1.

No. ofexperi-

StrainmentsNor

mals3GM38°AT2BE409T2642T2649T2650T24455234Pas

sagePE(%)13-4815-236-2012-1814-1915-2113-1918

±3±30

+12±7

±51±8297412n1.8

±1.7

±1.1±1.7

±1.6±2.0±2.1

±0.3b0.30.2o.e0.80.70.420619589157160138182Do±±±±±±±D,o996d12"179"9597548206441444413560±

17±

IG±1J±31"*47"±29"±

19a Average survival response of 4 normal control strains as reported previously

(24).6 Mean ±S.E.c Normal strain used as matched control in this set of experiments." Instances where D,0 or D0 values for the experimental strain and the normal

controls (mean values or GM38) differed significantly (p < 0.05).

ability to repair y-ray damage to their DNA. To measure repaircapacity, we first studied DNA repair replication in acutelyirradiated (50 kilorads) cultures (Chart 4). Under oxic radiation,all strains except the sensitive control strain (AT2BE) showedlevels of DNA repair replication similar to that of the normalstrain (GM 38) irrespective of the different y-ray sensitivityestablished in the colony-forming assay. Cells irradiated under

hypoxic conditions showed reduced levels of repair replicationin each case, consistent with the effect of oxygen reportedpreviously (24); oxygen enhancement effects of 1.5- to 2.2-

fold were observed. However, the level of repair in the strains

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Radiosensitivity in AML Cancer Family

0.001200 400 600 800 1000

DOSE (rods, N2 )

1200

Chart 3. Colony-forming ability after 60Co y-irradiation in nitrogen of the 3

cancer-affected family members, the father, and a normal and a radiosensitivecontrol.

100

, 80-

- 60-

10-

21-

i,

TI

,

GM38 »T2BE t09T 2612T 26M8T 2619T 2650T

Chart 4. Levels of repair replication induced in DMA of controls (GM38 andAT2BE) and AML family strains by 50 kilorads of 60Co y-irradiation under oxiaand hypoxia. Open bars, level of repair replication for oxic radiation; cross-

hatched bars, level for hypoxic radiation. The magnitude of each bar is the meanof 2 to 6 determinations (each corrected for background).

from the 5 family members tested was again the same as forthe normal control strain.

Using an in vitro enzymatic assay, we also investigated thetime-dependent repair of y-ray-induced single-strand breaksand M. luteus extract-sensitive sites in the DMA from severalstrains of this family (such sites are presumed to containradiation-damaged base or sugar moieties). Both the initialyield and the subsequent rate of disappearance of single-strand breaks (Chart 5a) and extract-sensitive sites (Chart 5t>)were similar in all strains tested; only in the repair-deficientcontrol strain (AT2BE) was site removal abnormally slow (25)(Chart 5o). Thus, the DMA repair capacity, as far as theseassays can tell us, is normal in strains from this family.

DISCUSSION

Our assessment of radiosensitivity in 6 strains which werederived from members of a "leukemia" family showed the

strains from clinically normal individuals to have normal radiosensitivity and the strains from members with cancer (or inthe case of 2642T, who later developed cancer) to be radiosensitive. The strain from the mother (2649T) showed the moststriking sensitivity while the strain from the proband was clearlynot as sensitive (Table 1; Chart 2). Although the designation ofa normal radioresponse by nature is somewhat arbitrary ratherthan absolute, our assignment of increased sensitivity in 3members of this family holds whether we use the mean D10value for either unrelated normal controls or clinically normalmembers of the family (i.e., 2647T, 2648T, and 2650T) forcomparison. We entertain the possibility that the increasedradiosensitivity is the expression of the "leukemogenic" factor

being transmitted through the maternal side of this family; thevariability in its in vitro expression may be due to modifyingfactors.

The complete concordance between the presence of cancers in vivo and cellular radiosensitivity (Dio values) in vitro isnoteworthy and could be considered as support for the interaction of hereditary and environmental factors in the development of cancer in members of this family. We believe it to befortuitous that the strains available from this family derived onlyfrom affected females and clinically normal males. The cancerproneness is clearly not restricted to females in the family; 2older sons developed AML (Chart 1).

Aside from the marked in vitro radiosensitivity observed inall AT homozygotes, moderate but significant increases in thelevel of y-ray sensitivity have been associated with severalgenetic recessive disorders [Friedreich's ataxia (10), Roth-mund-Thomson's syndrome (30), and AT hétérozygotes(24)]

and dominant disorders [hereditary retinoblastoma (33), Hunt-ington's disease (1, 14, 21), and tuberous sclerosis (21)],

several of which confer an increased cancer risk. The putativecancer factor transmitted in the present family shows a dominant mode of inheritance with incomplete penetrance amongmaternal relatives of the proband (409T) (31). Evidence fordefective DMA repair of y-ray-induced damage has so far onlybeen presented for 2 recessive traits: AT (25) and Rothmund-Thomson's syndrome (30). Our assays for DMA repair capacity

90 120

POST - RADIATION INCUBATION (mm)

Chart 5. Time-dependent disappearance of y-radioproducts from the DMA ofcontrol cultures and 3 family members, a. single-strand breaks; b. M. luteusextract-sensitive sites. Points, means of 3 or more determinations. The averagenumber of single-strand breaks immediately after irradiation was 0.98 ±0.15per 10' daltons of DMA while the average number of extract-sensitive sites was1.06 ±0.07 per 107 daltons of DMA.

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N. T. Bech-Hansen et al.

when applied to cells from members of the present familydemonstrated no significant differences from normal controlstrains. How extensively defective DNA repair figures in themoderately increased in vitro radiosensitivity now described byseveral laboratories for various genetic disorders and in fibro-

blasts from the family studied by us is not clear. New assayscapable of detecting a defined range of DNA lesions shouldclarify this situation.

The earlier observation of increased transformation by simianvirus 40 (31 ) of strains from the individuals which we report tobe radiosensitive could be explained by the presence of someputative DNA repair defect which leads to the persistence of asmall number of strand openings (undetected by the in vitroenzymatic assay; Chart 5). Such strand openings could providethe opportunity for an increased incorporation of viral DNA andin turn increase the chance for host cell transformation (19).

Further investigation in vitro of this family may help to understand some of the genetic factors that determine cancerproneness in humans. The study reported here does not provide direct evidence for a defect in DNA repair in the strainsfrom this family, but our results do suggest a correlation between cancer proneness in vivo and enhanced radiosensitivityin vitro. Should this relationship hold true for other cancerfamilies, in vitro radiosensitivity may have predictive value indetermining high-risk members in such families.

ACKNOWLEDGMENTS

We wish to acknowledge the helpful comments offered by Dr. J. D. Childs, Dr.N. E. Gentner, and Dr. D. K. Myers in the preparation of this manuscript; thetechnical assistance of P. A. Knight and A. K. Anderson; and the helpfuldiscussions with B. P. Smith and Dr. P. J. Smith.

Note Added In Proof

We recently assessed the y-ray sensitivity of a fibroblast strain

(AG3778) which derived from a maternal aunt with breast cancer andfound its radioresponse to be normal (D,0 of 396 ±9 rads comparedto 416 ± 18 rads for controls). This suggests that the "leukemiafactor" was not present and therefore not a contributing influence to

the developmment of cancer in this individual.

REFERENCES

1. Arieti, C. F. Survival and mutation in gamma-irradiated human cell strainsfrom normal or cancer-prone individuals. In: S. Okada, M. Imamura, T.Terashima. and H. Yamaguichi (eds.). Proceedings of the Sixth InternationalCongress of Radiation Research, pp. 596-602. Tokyo: Toppan Printing Co.,1979.

2. Arieti, C. F.. and Harcourt. S. A. Survey of radiosensitivity in a variety ofhuman cell strains. Cancer Res., 40. 926-932. 1980.

3. Bech-Hansen. N. T., Smith. B. P., Sell, B. M., and Paterson, M. C. Radiosensitivity in skin fibroblast cells from individuals with tuberous sclerosis.Proc. Am. Assoc. Cancer Res., 21: 47, 1980.

4. Chen, T. R. In situ detection of Mycop/asma contamination in cell culturesby fluorescent Hoechst 33258 stain. Exp. Cell Res., 14: 255-262, 1977.

5. Cox, R., and Masson, W. K. Changes in radiosensitivity during the in vitrogrowth of diploid human fibroblasts. Int. J. Radiât. Biol., 26. 193-196,1974.

6. Fraumeni, J. F. Jr.. Clinical patterns of familial cancer. In: J. J. Mulvihill, R.W. Miller, and J. F. Fraumeni, Jr. (eds.). Genetics of Human Cancer, pp.223-233. New York: Raven Press, 1977.

7. Ham, R. G. Clonal growth of mammalian cells in a chemically defined,synthetic medium. Proc. Nati. Acad. Sei. U. S. A., 53: 288-293, 1965.

8. Heath, C. W., Jr.. and Moloney, W. C. Familial leukemia: five cases of acuteleukemia in three generations. N. Engl. J. Med., 272. 882-887, 1965.

9. Hecht, F., and McCaw, B. K. Chromosome instability syndromes. In: J. J.Mulvihill, R. W. Miller, and J. F. Fraumeni, Jr. (eds.), Genetics of HumanCancer, pp. 105-123. New York: Raven Press, 1977.

10. Lewis, P. D., Corr. J B., Arlett. C. F., and Harcourt. S. A. Increased

sensitivity to gamma irradiation of skin fibroblasts in Friedreich's ataxia.

Lancet, 2. 474-475, 1979.11. Li, F. P. Investigative approach to familial cancer: clinical studies. In: J. J.

Mulvihill. R. W. Miller, and J. F. Fraumeni, Jr. (eds.). Genetics of HumanCancer, pp. 263-268. New York: Raven Press, 1977.

12. Lubiniecki, A. S., Blattner, W. A., and Fraumeni. J. F. Jr., SV-40 T antigenexpression in skin fibroblasts from normal individuals, patients with Fan-coni's anemia, and a family at high risk of leukemia. In: J. J. Mulvihill. R. W.

Miller, and J. F. Fraumeni, Jr. (eds.), Genetics of Human Cancer, pp. 377-381. New York: Raven Press, 1977.

13. McKeen. E. A.. Miller, R. W., Mulvihill, J. J., Blattner, W. A., and Lavine. A.S. Familial leukemia and SV-40 transformation. Lancet, 2. 310, 1977.

14. Miller. R. W. The feature in common among persons at high risk of leukemia.In: J. M. Yuhas. R. W. Tennant. and J. D. Regan (eds.). Biology of RadiationCarcinogenesis, pp. 45-50. New York: Raven Press, 1976.

15. Modon, B., and Lubin, E. Radiation induced leukemia in man. Ser. Haematol.,7. 192-210, 1974.

16. Moshell, A. N., Barrett, S. F.. Tarane, R. E., and Robbins. J. H. Radiosensitivity in Huntington's disease: implications for pathogenesis and presymp-

tomatic diagnosis. Lancet, 1: 9, 1980.17. Muller, H. J.. Oster. I. I., and Zimmering. S. Are chronic and acute gamma

irradiation equally mutagenic in DrosophiVa? In: F. H. Sobéis(ed.), Repairfrom Genetic Radiation Damage, pp. 275-304. New York: Pergamon Press1963.

18. Mulvihill. J. J. Genetic repertory of human neoplasia. In: J. J. Mulvihill, R. W.Miller, and J. F. Fraumeni, Jr. (eds.). Genetics of Human Cancer, pp. 137-143. New York: Raven Press, 1977.

19. Paterson, M. C. Environmentally induced DNA damage, its faulty repair, andmalignant genetic diseases. In: H. Koprowski (ed.), Neoplastic Transformation: Mechanisms and Consequences, pp. 39-53. Berlin: Dahlem Konf.,1977.

20. Paterson, M. C. Environmental carcinogenesis and imperfect repair of damaged DNA in Homo sapiens: causal relation revealed by rare hereditarydisorders. In: A. C. Griffin and C. R. Shaw (eds.). Carcinogens: Identificationand Mechanisms of Action, pp. 251-276. New York: Raven Press, 1979.

21. Paterson, M. C., Bech-Hansen, N. T., and Smith, P. J. Heritable radiosensitive and DNA repair-deficient disorders in man. In: E. Seeberg (ed.).Chromosome Damage and Repair. New York: Plenum Publishing Corp., inpress, 1981.

22. Paterson, M. C.. Smith, B. P.. Lohman, P. H. M., Anderson, A. K., andFishman, L. Defective excision repair of y-ray-damaged DNA in human(ataxia telangiectasia) fibroblasts. Nature (Lond.). 260. 444-447, 1976.

23. Paterson, M. C., Smith, B. P., and Smith, P. J. Measurement of enzyme-sensitive sites in UV- or gamma-irradiated human cells using Micrococcusluteus extracts. In: E. C. Friedberg and P. C. Hanawalt (eds.). DNA Repair:a laboratory manual of research procedures. Vol. 1, Part A, pp. 99-111.New York: Marcel Dekker, 1980.

24. Paterson. M. C.. Smith, B. P., Smith, P. J., and Anderson, A. K. Enhancedradiosensitivity of cultured fibroblasts from ataxia telangiectasia hétérozygotes manifested by defective colony-forming ability and reduced DNArepair replication after hypoxic y-irradiation. Cancer Res., 39. 3725-3734,1979.

25. Paterson. M. C., and Smith, P. J. Ataxia telangiectasia: an inherited humandisorder involving hypersensitivity to ionizing radiation and related DNA-damaging chemicals. Annu. Rev. Genet., Õ3:291-318, 1979.

26. Paterson, M. C., Smith. P. J., Bech-Hansen, N. T., Smith. B. P.. and Sell. B.M. y-Ray hypersensitivity and faulty DNA repair in cultured cells fromhumans exhibiting familial cancer proneness. In: S. Okada. M. Imamura, T.Terashima, and H. Yamaguichi (eds.), Proceedings of the Sixth InternationalCongress of Radiation Research, pp. 484-495. Tokyo: Toppan Printing Co..1979.

27. Paul, J. Morphological studies. In: Cell and Tissue Culture. Ed. 4, p. 318.Edinburgh: Churchill Livingstone. 1970.

28. Peden, K. W. C. A rapid and simple method for the detection of Mycop/asmaand other intracellular contaminants. Experientia (Basel), 3Õ. 1111-1112.1975.

29 Schneider. E. L.. and Stanbridge. E. J. Comparison of methods for thedetection of mycoplasmal contamination of cell cultures: a review. In Vitro(Rockville), 11: 20-34, 1975.

30. Smith. P. J., and Paterson, M. C. Rothmund Thomson syndrome: in vi'fro

radiosensitivity and defective DNA repair in cultured skin fibroblasts. Proc.Am. Assoc. Cancer Res., 21: 110, 1980.

31. Snyder, A. L., Li, F. P., Henderson. E. S., and Todaro, G. J. Possibleinherited leukaemogenic factors in familial acute myelogenous leukemia.Lancet, ). 586-589, 1970.

32. Taylor, A. M. R., Harnden. D. G., Arlett, C. F., Harcourt. S. A., Lehman, A.R., Stevens, S., and Bridges, B. A. Ataxia telangiectasia: a human mutationwith abnormal radiation sensitivity. Nature (Lond.), 258. 427-429, 1975.

33. Weichselbaum. R. R., Nove, J., and Little. J. B. X-Ray sensitivity of diploidfibroblasts from patients with hereditary or sporadic retinoblastoma. Proc.Nati. Acad. Sei. U. S. A., 75: 3962-3964, 1978.

34. Weichselbaum. R. R.. Nove. J., and Little, J. B. X-Ray sensitivity of fifty-three human diploid fibroblast cell strains from patients with characterizedgenetic disorders. Cancer Res., 40: 920-925, 1980.

2050 CANCER RESEARCH VOL. 41

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1981;41:2046-2050. Cancer Res   N. Torben Bech-Hansen, Brenda M. Sell, John J. Mulvihill, et al.   with Acute Myelogenous Leukemia

Radiosensitivity and Cancer in a Familyin VitroAssociation of

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