Biomedical subjects
Publications and source records attributed to G J Goldenberg.
Four steroidal nitrosoureas with structures which may permit specific binding to estrogen receptor were synthesized. Inhibitory activity was observed against the growth of the DMBA-induced transplantable rat mammary tumor 13762.
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The stimulation of uridine uptake, brought about by the addition of serum or insulin to quiescent 3T3 fibroblasts, is associated in the half-saturation concentration of the uridine phosphorylating system for the substrate ATP, with relatively little change in the maximum uptake or in the affinity for uridine. In stimulated cells the Km towards ATP fell in the range 0.053--0.187 mM, while V max was 34 to 52 pmoles/10(6) cells/min. In quiescent cells these values were 2.89--4.22 mM and 74.5--126 pmoles/10(6) cells/min, respectively. No difference was found, however, between the Km's for ATP when phosphorylation of uridine was determined using cell-free extracts prepared from either quiescent cells or from stimulated cells.
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A double-blind study of 62 normal women was carried out to determine if there was any correlation between the mean score of six weekly leucocyte-migration-inhibition tests (L.M.T.) against breast-cancer antigen, xeromammographic findings, and the presence of other epidemiological risk factors for the development of breast cancer. 36 women had abnormal mammograms, and 11 of these 26 (30.5%) had a mean L.M.T. score greater than or equal to 10%. 26 women had normal mammograms, and only 1 of these (3.8%) had a mean value greater than or equal to 10%. This difference was significant (p less than 0.02). A family history of breast cancer and/or previous surgery for cystic and proliferative disease also correlated significantly with L.M.T. score (p less than 0.05); the combined presence of epidemiological risk factors and an abnormal mammogram correlated most strongly with L.M.T. score (p less than 0.01). Although the results may indicate an "immunological risk factor" towards the development of breast cancer, the biological relevance of this observation remains to be proven.
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The mechanism of uptake of nitrosoureas by L5178Y cells in vitro was investigated. A time course of the uptake of radioactivity on incubation of L5178Y lymphoblast with [14C]-1,3-bis(2-chloroethyl)-1-nitrosourea was linear for 30 min and then entered a plateau phase; it was markedly temperature dependent. A similar time course for cells incubated with [14C]ethylene-labeled 1-(2-chlorethyl)-3-cyclohexyl-1-nitrosourea reached equilibrium rapidly, was temperature independent, and resulted in a relatively low level of uptake of radioactivity. However, cells treated with 3-[cyclohexyl-14C]-1-(2-chlorethyl)-1-nitrosourea had a time course that was linear for 30 min, resulted in much higher levels of uptake of radioactivity, and was strongly temperature dependent. These findings, at least for 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, suggest that some drug decomposition precedes uptake. The percentage of radioactivity found in the cell sap fraction was at least 85% of total cell activity when cells were incubated with any of the three 14C-labeled nitrosoureas. Furthermore, thin-layer chromatography of the cell sap fraction revealed the presence of free intact drug. These findings indicate that intracellular uptake of intact nitrosoureas occurred. A time course of uptake of intact 1,3-bis(2-chloroethyl)-1-nitrosourea reached equilibrium rapidly with cell/medium distribution ratios of 0.2 to 0.6 and was temperature independent. The addition of excess unlabeled 1,3-bis(2-chlorethyl)-1-nitrosourea or 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea had no effect on uptake of [14C]-1,3-bis(2-chloroethyl)-1-nitrosourea, These findings suggest that uptake of intact 1,3-bis(2-chloroethyl)-1-nitrosourea was by passive diffusion. A time course of the uptake of intact 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea with either [14C]ethylene- or ring-labeled drug rapidly reached equilibrium, was temperature independent, and attained a cell/medium ratio greater than unity. Uptake of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea was sodium independent and was unaffected by the metabolic inhibitors (sodium fluoride, sodium cyanide, or 2,4-dinitrophenol) or by urea, a potential physiological competitor. Furthermore, addition of unlabeled 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea or 1,3-bis(2-chlorethyl)-1-nitrosourea had no effect on uptake of labeled 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea. These findings suggest that uptake of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea also occurs by passive diffusion.
Mechanism of transport of the alkylating agent [14C]melphalan was investigated in L5178Y lymphoblasts in vitro. A time course of melphalan uptake was approximately linear for 5 to 10 min and thereafter entered a plateau region. Evidence that unidirectional influx of melphalan is carrier mediated was that uptake obeyed simple Michaelis-Menten kinetics, that it demonstrated chemical specificity, and that the cell/medium distribution ratio of drug decreased with increasing extracellular drug concentration. The kinetic parameters for melphalan transport consisted of a Km (mean +/- S.E.) of 1.53 +/- 0.18 X 10(-4) M and a transport capacity (Vmax) of 3.48 +/- 0.31 X 10(-17) mole/min/cell. Findings suggesting that transport was at least in part energy dependent and not simply a passive process were that drug uptake was temperature sensitive and sodium dependent. Analysis of cell sap constituents indicated the presence of intact drug within the cell. The percentage of radioactivity (mean +/- S.D.) found in the cell sap fraction was 95.8 +/- 2.2% of total cell activity, and 92.6 +/- 4.1% of this was trichloroacetic acid soluble. Thin-layer chromatography of the cell sap fraction and medium each revealed that the majority of radioactivity migrated as a single peak with an RF value identical with that obtained for free drug. The alkylating potential of intact drug complicated interpretation of the finding of apparent uphill transport against a concentration gradient. This observation, together with the relatively low cell-medium ratio (mean +/- S.D.) of 3.07 +/- 1.07, favors the concept that melphalan transport occurs by a facilitated diffusion process, although an active transport system has not been entirely excluded. The relative insensitivity of melphalan uptake to a wide range of metabolic inhibitors also suggests that transport is by a facilitated diffusion mechanism rather than an active process. Other alkylating agents and several amino acids including the L and D isomers of phenylalanine did not inhibit melphalan transport; thus a native substrate was not identified for the melphalan carrier and transport was by a mechanism separate from that of other alkylating agents.
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The effect of morphine and cocaine on the transport of hydrolyzed nitrogen mustard (NH2-OH) and choline by peripheral blood cells of normal subjects and patients with chronic lymphocytic leukemia, acute lymphoblastic leukemia, and acute myeloblastic leukemia was determined. Transport of HN2-OH by lymphocytes from normal individuals and patients with chronic lymphocytic leukemia was stimulated by morphine and cocaine and, in each case, the effect was statistically significant (P less than 0.05 or greater). However, choline transport by normal lymphocytes was not altered by cocaine and was only slightly stimulated by morphine; choline transport by lymphocytes from patients with chronic lymphocytic leukemia was not stimulated by either morphine or cocaine. HN2-OH and choline transport by cells from patients with either acute lymphoblastic or myeloblastic leukemia was stimulated to a comparable degree by both drugs. Stimulation of HN2-OH transport by morphine and cocaine was greater in normal lymphocytes than in acute leukemic cells and the differences were highly significant (p less than 0.001). Conversely, stimulation of choline transport was more marked in acute leukemic cells than in normal lymphocytes, and these differences were also highly significant (p less than 0.001). It was previously shown that transport of nitrogen mustard by normal and leukemic human cells was biphasic in nature, consisting of a choline-independent component at "high" drug concentrations and a choline-dependent system at "low" substrate concentrations. The preferential stimulation of the low-dose, choline-dependent system by morphine and cocaine in acute leukemic cells relative to that observed in normal lymphocytes suggests a possible mechanism of increasing the therapeutic index of nitrogen mustard.
Epstein-Barr virus, the apparent cause of infectious mononucleosis, may also be an etiological agent in nasopharyngeal carcinoma and Burkitt's lymphoma. Lymphocytes from normal individuals with anti-Epstein-Barr virus antibody activity may be sensitized to Epstein-Barr virus and contain transfer factor with the potential to program and/or recruit other lymphocytes to react against the virus and/or viral antigens. A patient with nasopharyngeal carcinoma refractory to conventional therapy was treated with transfer factor obtained from normal, young adults with previous history of infectious mononucleosis. Following immunotherapy, apparent slowing of tumor growth was observed, which was associated with intense lymphocytic infiltration of the tumor and reconstitution of delayed cutaneous hypersensitivity reactions to microbial recall antigens. A double-blind randomized clinical trial has been initiated to determine whether transfer factor immunotherapy is a useful adjunct to radiotherapy in the primary treatment of patients with nasopharyngeal carcinoma. If successful, a similar trial might be considered for African patients with Burkitt's lymphoma.
The peripheral leukocyte migration inhibition test has been used to assess cellular immunity to soluble antigen extracts of breast cancer in patients and normal controls. In sequential tests over several weeks, 23 of 23 patients with breast cancer in remission reacted intermittently, with 67 of 139 tests (48%) being positive (greater than or equal to 20% migration inhibition). Similarly, 6 of 10 patients in relapse reacted intermittently showing 16 of 61 positive tests (26%) and 126 of 129 normal females reacted intermittently showing 135 of 512 positive tests (26%). The mean percentage of migration inhibition for all tests in patients in remission was 16.4 +/- 1.2% and that for normal controls was 7.2 +/- 0.7%; this difference was highly significant (p less than 0.001). The value for all tests in patients with relapse was 11.8 +/- 1.4%; this was statistically lower than that for patients in remission (p less than 0.05) but statistically higher than that for normal controls (p less than 0.05). A few normal women, some with high risk factors such as a strong family history and/or fibrocystic and proliferative disease, had a mean percentage of migration inhibition value in the range of that for patients with breast cancer. Mean values of sequential tests may be a more meaningful index of cellular immunity against breast cancer antigen in all groups.
An investigation was undertaken of the mechanism of resistance to nitrogen mustard (HN2) and other alkylating agents, with particular emphasis on the interaction between cross-resistance and drug transport mechanisms in L5178Y lymphoblasts. Dose-survival curves demonstrated that the D0 for HN2-sensitive cells (L5178Y) treated with HN2 in vitro was 9.79 ng/ml and the D0 for HN2-resistant cells (L5178Y/HN2) was 181.11 ng/ml; thus, sensitive cells were 18.5-fold more responsive than were resistant cells and the difference was highly significant (p less than 0.001). A similar evaluation of 5 additional alkylating agents, including chlorambucil, melphalan, 1,3-bis(2-chloroethyl)-l-nitrosourea, Mitomycin C, and 2,3,5-tris(ethyleneimino)-1,4-benzoquinone, revealed that L5178Y/HN2 cells were also cross-resistant, in part, to each of these compounds. Furthermore, the degree of cross-resistance was remarkably similar; for each drug, dose-survival studies showed that HN2-resistant cells were approximately 2- to 3-fold more resistant to therapy than were sensitive cells. L5178Y/HN2 cells were also cross-resistant to cyclophosphamide in vivo; after treatment with cyclophosphamide, DBA/2 female mice that were given inoculations of L5178Y cells, but not those given transplants of L5178Y/HN2 cells, showed a significant prolongation of survival time (p less than 0.01). Transport of HN2, hydrolyzed derivative of HN2 and choline by L5178Y lymphoblasts in vitro was not competitively inhibited by any of the other alkylating agents, suggesting that transport of these compounds was by an independent mechanism. These findings suggest that the mechanism whereby L5178Y/HN2 cells are cross-resistant to other alkylating agents may involve nontransport factors and that these other drugs may bypass a major portion of HN2 resistance by using independent transport systems.
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The simultaneous occurrence of sarcomas in a husband and wife is documented. The wife first presented with an undifferentiated uterine sarcoma, and within six months of the onset of her disease her husband developed an anaplastic liposarcoma. This finding is considered in the light of recent evidence suggesting a possible viral etiology for human sarcomas.
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