PHOSPHORUS METABOLISM OF NEOPLASTIC TISSUES
(MAMMARY CARCINOMA, LYMPHOMA, LYMPHOSARCOMA)
AS INDICATED BY RADIOACTIVE PHOSPHORUS '
H. B. JONES, I. L. CHAIKOFF, AND JOHN H. LAWRENCE
(From the Division of Physiology of the Medical School and the Radiation Laboratory,
University of California)
In previous studies from these laboratories, radioactive phosphorus was
used to determine the rate of phospholipid turnover in 4 types of transplantable
tumors: a mammary carcinoma, a lymphoma, a lymphosarcoma, and sarcoma
180 (1, 2). Some distinctive features of the metabolism of these neoplastic
tissues were described: (a) the fact that their phospholipid turnover bears a
greater resemblance to that of the more active tissues, such as liver, kidney,
and intestine, than to that of the less active tissues, such as muscle or brain;
( b ) the fact that, while each type of tumor displays a characteristic phospholipid activity, the rate of turnover is not uniform in all types. Thus the phospholipid activity of mammary carcinoma and of lymphosarcoma was at least
twice as great as that observed in sarcoma 180 and lymphoma. The individuality of the phospholipid metabolism of each type of neoplasm was clearly
established by employment of a method of tumor implantation that permitted
the growth of tumors of two or three types under identical metabolic environment. Even under such conditions the characteristics of each tumor are
retained.
In the present investigation another phase of the metabolism of these neoplastic tissues has been investigated. Radioactive phosphorus was injected
into tumor-bearing mice, and the rate of uptake of the total labeled phosphorus
by the neoplastic tissues was compared with that of the normal tissues of the
host. As regards one of these tumors, namely the lymphoma, it has previously
been shown that it retains more labeled phosphorus for longer periods than
liver and lymph nodes and that spleen and lymph nodes invaded by lymphoma
cells show a higher phosphorus uptake than normal tissues such as muscle,
liver, spleen, and lymph nodes (3, 4). .
The number of mice used in this investigation and their treatment are
summarized in Table I. Mice of the A strain were employed, receiving, as
in the preceding study ( 5 ) , a diet in pellet form supplemented by whole oats,
the feeding of which was not interrupted during the experiment.
Tumors were produced by inoculation of particles by the trocar method.
Each animal received transplants of two or three different types of neoplastic
tissue. In the case of double inoculations transplants were placed in both
1 Aided by grants from the Dazian Foundation for Medical Research. The assistance furnished by the Works Progress Administration (official project No. 65-148-62, Unit A6) is gratefully acknowledged.
243
244
H. B. JONES, I. L. CHAIKOFF, AND JOHN H. LAWRENCE
TABLE
I: Summary of Tumor Ex@riments
0.60 m
Group
and
Fir.
No.
No.
of
mice
used*
.
P aa
N~,I!Po~
injected per
mouse
Weight of
mice t
Tumor
Tumors
inoculated
Range
- : ;A
(gm.)
(
Initial sample
Final sample
AverAveram
Age
age
Age
(days) weight (daya) weight
(em.)
(am.)
Volume Micro) (ml.) curies $
----
-----1%
22
20-25
22.7
0.2
4
Lymphosarcoma
Mammarycarcinoma
11
11
0.22
0.29
15
15
0.72
0.53
211
10
2630
28.2
0.2
4
Lymphosarcoma
Lymphoma
21
21
1.24
0.66
28
28
1.98
0.70
39
15
21-24
22.0
0.2
24
Lymphosarcoma
Mammary carcinoma
Lymphoma
11
11
11
0.21
0.22
0.17
15
15
15
0.73
0.52
0.43
411
6
27-29
28.0
0.2
2
Lymphosarcoma
Mammary carcinoma
Lymphoma
25
25
25
0.72
0.62
0.55
27
27
27
0.70
0.63
0.58
* Mice approximately three months of age and of both sexes were used.
activitiee recorded were apparently independent of the sex of the host.
t At the time of Pa administration.
Activities standardized against uranium.
8 G r w evidences of metastases were not found.
11 Metastases revealed by enlarged spleen and lymph nodes.
The phosphorus
axillary regions. In the animals in which tumors of three types were permitted to develop simultaneously, inoculations were made in the nape, as well
as in the axillae. The following combinations of fraternal tumors were investigated: (a) mammary carcinoma and lymphosarcoma, ( b ) lymphoma and
lyrnphosarcoma, (c) lymphoma, lyrnphosarcoma, and mammary carcinoma.'
In the first two groups .shown in Table I, double inoculations were studied;
the mice of the other two groups received triple inoculations.
Each mouse received intraperitoneally 0.2 C.C. of an isotonic solution of
radioactive sodium phosphate (NhHPO,) containing 3 mg. of phosphorus per
The radioactivity of the injected phosphate is shown in Table I. The
C.C.
animals were sacrificed at various intervals thereafter and the tumors were
excised. The removal of the neoplastic tissues has been described elsewhere
1 2). The samples taken represented the solid tumor tissues. The tumors
were peeled away from the subcutaneous tissues of the host, and all visible
necrotic portions were removed. Following dissection, the tissue was cut
open to expose any cysts and blotted to remove excess surface fluid., The
whole of the tumor mass was then reduced to a uniform paste and samples
were transferred to a cellophane cone inside a weighing vial in the manner
2 DifEerent neoplasms growing side by side in the same animal are referred to as fraternal
tumors.
8The tumors studied were: the'mammary carcinoma induced by Strong in the A strain by
prolonged folliculin administration (6) ; the lymphoma described by Lawrence and Gardner (7) ;
the lymphosarcoma initiated by Gardner by prolonged folliculin injection. These tumors are
transpIantable in the genetically unifotm A and ABC strains of mice.
4 Fluid cysts are prevalent in the mammary carcinoma.
PHOSPHORUS METABOLISM OF NEOPLASTIC TISSUES
245
described for the normat tissues (5). Duplicate samples were taken from
each tumor and each of the points in Figs. 1-5 represents the average of 4 to
10 separate determinations. The method by which the radioactivity was
measured has been recorded previously ( 1, 2 ) .
Fro. 1. LABELED
P~os~ao~
CONTENT
us
PER GRAMOP MAMMARY
CARCINOMA
AMJ
LYMPEOSARCOMA
IN DOUBLY
INOCULATED
MICE
The ordinates of the solid line represent the percentage of administered phosphorus found per
gram of tissue. Each point is the mean of 10 separate determinations on tumors removed from
S mice. The broken lines are the growth curves for these tumors.
Double Inoculations of Mammary Carcinoma and Lymphosarcoma (Young
Tumors): The first samples of the fraternal tumors represented in Fig. 1 were
removed ten hours after and the last one hundred hours after the administration of labeled phosphorus. These neoplasms were young at the time the first
samples were taken, namely eleven days old, the mass in each axilla weighing
at this time between 0.2 and 0.3 gm. The mammary carcinoma and the
lymphosarcoma showed a rapid growth at this stage; ninety hours after the
first sample had been removed, they attained weights of 0.53 and 0.72 gm.,
respectively (Fig. 1 ) .
The phosphorus activities of mammary carcinoma and of lymphosarcoma
6
Refers to the uptake of labeled phosphorus.
246
H. B. JONES, I. L. CHAIKOFF, AND JOHN H. LAWRENCE
The ordinates of the solid line represent the percentage of administered phosphorus found per
gram of tissue. Each point is the mean of 4 to 6 separate determinations on tumors removed from
2 or 3 mice. The broken lines are the growth curves for these tumors.
are high. At the ten-hour interval, 4.5 per cent of the administered labeled
phosphorus was deposited per gram of mammary carcinoma, and an even
greater amount was deposited at this time in the lymphosarcoma. As regards
height of activity at this interval, these tumors resemble the most active of the
normal tissues, namely, kidney, liver, and small intestine, but they differ from
these in that no rapid drop occurs after the maximum is attained. Thus,
while liver and kidney showed a rapid rise and fall in their content of labeled
phosphorus after the administration of the radioactive isotope, both neoplastic tissues retained their accumulated phosphorus at the high concentrations throughout the period of observation, namely one hundred hours. The
capacity to adhere to its labeled phosphorus is particularly well brought out
by the mammary carcinoma. At the one-hundred-hour interval each gram of
this tissue contained a little over 3 per cent of the administered labeled phosphorus, a value only 30 per cent less than that present ninety hours earlier.
Double Inoculations of Lymphoma and Lymphosarcoma (Old Tumors):
The tumors represented in Fig. 2 were much older than those in Fig. I. At
247
PHOSPHORUS METABOLISM OF NEOPLASTIC TISSUES
9.0.
0.9.
3 0.8,
(n
U)
W
3
28.0.
o
I
0 LYMPHOMA
@ LYMPHOSARCOMA
MAMMARY CARCINOMA
-
/
/
/
INOCULA-~K>NHOURS AFTER P x ADMINISTRAT ION
FIG.3. LABELED
PHOSPHORUS
CONTENT
PER GRAMOF LYMPHOMA,
LYMPHOSARCOMA,
AND MAMMARY
CARCINOMA
IN TRIPLYINOCULATED
MICE
The ordinates have the same meaning as for Fig. 1. Each point is the mean of 6 separate
determinations on tumors from 3 mice.
the time the first samples were removed, the lymphoma and lymphosarcoma
were twenty-one days old; when the last samples were taken, twenty-eight
days old. The lymphoma showed little change in size during the 170-hour
period of study, whereas during this interval the lyrnphosarcoma was still
actively growing. The average weight of each mass of lymphoma was 0.66
grn., whereas the weight of the lymphosarcoma varied from 1.2 grn. at the
beginning to about 2.0 gm. at the end of the period of observation.
With the aid of radioactive phosphorus, it was previously shown (1, 2)
that the rates of regeneration of newly synthesized phospholipid are about the
same in mammary carcinoma and in lymphosarcoma. The present study
(Fig. 1) shows that the activities of the total labeled phosphorus are also
roughly similar in these two neoplasms. The phospholipid activity of the
lymphoma, however, differed from that of both the mammary carcinoma and
the lymphosarcoma. I t was estimated that the phospholipid activity of the
two latter was approximately twice that of the lymphoma. This was found to
be the case when the lymphoma was grown singly as well as when it was
grown in the same animal simultaneously with lymphosarcoma and mammary
248
H. B. JONES, I. L. CHAIKOFF, AND JOHN H. LAWRENCE
vA
a
o
w 9.0,
3
2 8.0-
0
I
LYMPWMA
LYMPHOSARCOMA
MAMMARY CARCINOMLr
2
$7.0.
r3
W
22
I-
8
gs.0-
n
% 5.0-
1.0-
30.8- b4.0.
' - I -
0
n
't"---"'f"-"'-----
-'
t
I
1 0 20
HWRS AFTER
lN O C U T I O N
600'0
HRS
I
I
1
1
I
40 50 6 0 70
ADMINISTRATION
FIG.4. LABELED
PEOSPEORUS
CONTENTPER GMX OF LYXPHOMA,LYMPEKOSARCOMA,
am, MAMMARY
CARCINOMA
m TRIPLY
INOCULATED
MICE
The ordinates have the same meaning as for Fig. 1. Each point is the mean of 4 separate
determinations on tumors removed from 2 mice.
carcinoma. Surprisingly enough, the total phosphorus turnover of the lymphoma closely resembles that of the other two tumors as regards both the rate
at which labeled phosphorus is incorporated and the rate at which phosphorus
is lost (Figs. 1 and 2).
Some difference was observed in the levels of phosphorus activity for
lymphosarcoma in the two experiments shown in Figs. 1 and 2. A closer
agreement, however, is not to be expected in view of the age difference in the
two groups of tumors examined. The lymphosarcomas shown in Fig. 1 were
eleven days old when the first sample was removed; those in Fig. 2 were
twenty-one days old.
Triple Inoculations of Lymphoma, Lymphosarcoma, and Mammary Carcinoma: Two experiments were conducted with groups of mice in which all
3 tumors were grown simultaneously in the same animal. The results are
shown in Figs. 3 and 4. The tumors represented in Fig. 3 were eleven days
old; those in Fig. 4 twenty-five days old, at the time the radioactive phosphorus was injected.
PHOSPHORUS METABOLISM OF NEOPLASTIC TISSUES
249
0 LYMPHOMA
@
a
LYMPHOSARCOMA
MaMMARV CARCINOMA
FIG.5. COMPARATIVE
PHOSPHORUS
ACTMTIESOF NORMAL
AND NEOPLASTIC
TISSUES
The curves have been taken from the preceding paper and represent activities of normal tissues
in normal mice. As noted above, the normal tissues of one group of triply inoculated mice (the
same animals shown in Fig. 3) were examined and their phosphorus activities agreed closely with
curves depicted above. The values for lymphoma, lymphosarcoma, and mammary carcinoma have
been taken from the experiments illustrated in Figs. 1-4.
Although the values obtained for mammary carcinoma in both experiments
were somewhat lower than those for lymphoma and lyrnphosarcoma, it is clear
that the turnover of labeled phosphorus is similar in all three tumors.
The phosphorus turnover of the liver, kidney, skeletal and cardiac muscle,
and blood of the group of mice represented in Fig. 3 was determined. The
curves were in good agreement with those previously obtained for the same
tissues of normal mice, which are recorded in the preceding paper.
In the experiments represented in Fig. 3, the rate of growth of lymphosarcoma soon outstripped the growth of mammary carcinoma and lymphoma,
yet little difference was observed in the phosphorus activities of these three
tumors. Even when the rate of increase in mass was no longer pronounced, as
in the tumors shown in Fig. 4, the level of phosphorus activities was as high
250
H. B. JONES, I. L. CHAIKOFF, AND JOHN H. LAWRENCE
as that during the process of rapid growth as shown by the tumors in Fig. 3.
I t should not be inferred from these results, however, that no relation exists
between phosphorus turnover of a tumor and its rate of growth, since increase
in mass as determined merely by weight of the excised tumor cannot at one
and the same time be a safe index of cell proliferation, mitotic activity, and
cell degeneration. Indeed, it is of interest to note here that Marshak has suggested recently that the high uptake of radiophosphorus by tumor nuclei is a
function of mitotic activity (8).
The total phosphorus turnover of three neoplastic tissues, a mammary
carcinoma, a lymphoma, and a lymphosarcoma, was measured early and late
in their development by means of the radioactive isotope of phosphorus.
Their activities were compared with those of normal tissues as well as with
one another, the latter comparison being made possible by means of double
and triple inoculation in which two and three of these tumors were permitted
to grow simultaneously in the same animal. For convenience, the data have
been summarized in Fig. 5, in which the phosphorus activities of the three
tumors are shown in relation to similarly measured activities in normal tissues.
(1) These neoplastic tissues show a high and rapid uptake of labeled
phosphorus in the early intervals after the administration of the radioactive
isotope. In the general level of their phosphorus activities, they resemble the
most active of the normal tissues, namely liver, kidney, and small intestine.
( 2 ) These neoplastic tissues show a pronounced capacity for retaining
labeled phosphorus for long periods. This characteristic serves to distinguish
them from normal tissues with equally high levels of phosphorus activities.
(3) The general trend of phosphorus activity in these three tumors was
similar. No difference in the rate of deposition of total labeled phosphorus
by the lymphoma and the lymphosarcoma was detectable, a finding of interest
in view of the striking dissidarity of their phospholipid activities. The
phospholipid activity of lymphosarcoma is at least twice as great as that of
lymphoma.
(4) The phosphorus activities of lymphoid tumors need bear no resemblance to those of their closely related normal tissue, lymph nodes. The phosphorus activity of the lymphoma and of the lymphosarcoma was at least twice
that of normal lymph nodes.
1. JONES,H. B., CHAIKOPF,
I. L., AND LAWRENCE,
J. H. : J. Biol. Chem. 128 : 631, 1939.
2. JONES,H. B., CHAIKOFF,
I. L., AND LAWRENCE,
J. H.: J. Biol. Chem. 133: 319, 1940.
3. LAWRENCE,
J. H., AND SCOTT,K. G.: Proc. Soc. Exper. Biol. & Med. 40: 694. 1939.
4. LAWRENCE,
J. H., TUTTLE,L. W., SCOTT,K. G., AND CONNOR,
C. L.: J. ~ l i n Investiga.
tion 19: 267. 1940.
J. H.: Am. J. Cancer 40: 235, 1940,
5. JONES,H. B.,CHAIKOFF, I. L.,AND LAWRENCE,
6. STRONG,
L. C.: J. Heredity 27: 21, 1936.
7. LAWRENCE,
J. H., AND GARDNER,
W. U.: Am. J. Cancer 33: 112, 1938.
8. MARSHAK,
A,: Science 92: 460, 1940.