Tamoxifen in the treatment of refractory lymphoma

Inhibitory effects of tamoxifen and doxorubicin, alone and in combination, on the proliferation of the MG63 human osteosarcoma cell line

The present study aimed to compare the combined effect of tamoxifen (TAM) and doxorubicin (ADM) with the individual effects of TAM and ADM alone on the MG63 human osteosarcoma cell line. Estrogen receptor (ER) expression was detected in the MG63 cells using reverse transcription PCR. The morphological changes during the inhibition of cell growth were observed using an inverted microscope and a 3-(4, 5-dimethy1-2-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) colorimetric assay following the individual or combined addition of TAM and ADM. ERα and ERβ expression was detected in the MG63 cells. The typical apoptotic cell morphology was observed in all groups, with the exception of the control group. The MTT colorimetric analysis demonstrated that the rate of inhibition of cell proliferation in the combination group was significantly increased compared with that in the other groups (P<0.05). ERα and ERβ expression was detected in the MG63 human osteosarcoma cells. TAM and ADM alone were able to inhibit cell proliferation. The combination of TAM and ADM significantly enhanced the inhibitory effect, partly through the enhanced sensitivity of the cells to ADM by TAM, which caused the inhibition of cell proliferation and apoptosis.

Improved antitumoral properties of pure antiestrogen RU 58668-loaded liposomes in multiple myeloma

In most of multiple myeloma (MM) cells, the "pure" antiestrogen (AE) RU 58668 (RU) induced either a G1-arrest (LP-1, OPM-2, NCI-H929, U266 cells) or apoptosis (RPMI 8226 cells). In RPMI 8226 cells, RU activates a caspase-dependent cell death pathway leading to the release of cytochrome c, the decrease of the essential MM survival factor Mcl-1, the cleavage of Bid and the activation of caspases-3 and -8. Incorporation of RU in pegylated cholesterol-containing liposomes allowed a controlled RU release, improving its anti-proliferative and apoptotic effects in cells. In RPMI 8226 xenografts, i.v. injected RU-liposomes but not free RU, exhibited antitumor activity. In vivo, RU-liposomes triggered the mitochondrial death pathway, concomitantly with a down-regulation of Mcl-1 and Bid cleavage. The decrease of CD34 immunoreactivity indicated a reduction of angiogenesis. The decrease of VEGF secretion in vitro supported a direct effect of RU on angiogenesis. These pro-apoptotic and antiangiogenic effects were explained by a prolonged exposure to the drug and to the endocytosis capacity of liposomes which might increase RU uptake and bypass a membrane export of free RU. Thus, these combined enhanced activities of RU-liposomes support that such a delivery of an AE may constitute a strategy of benefit for MM treatment.

Non-Hodgkin's Lymphoma of the Breast: A Report of 19 Cases and a Review of the Literature

PURPOSE

Non-Hodgkin's lymphoma of the breast represents 0.04%-0.50% of malignant lesions of the mammary gland. In this article, we report a single institution's experience with this rare disease.

MATERIALS AND METHODS

Between 1982 and 1997, 19 patients with breast lymphoma were diagnosed, treated, and followed at this institution.

RESULTS

There were 18 female patients and 1 male patient. All but one were cases of aggressive B-cell lymphoma. Ann Arbor stages were IE (n=5), IIE (n=9), IIIE (n=2), and IV (n=3). International Prognosis Index scores were 0 (n=2), 1 (n=8), 2 (n=7), and 3 (n=2). According to the Wiseman and Liao classification established in 1972, 11 cases were primary lymphomas of the breast, and 8 cases were secondary involvement of the breast. Median survival time was 21.5 months (range, 5.1-114.7 months). The 5-year overall survival was 29%. Median event-free survival time was 8.3 months. The clinical, radiologic, and histologic patterns of presentation match previously published data, even if the response rates and the survival times seem disappointing, probably because of the initial treatment by tumorectomy or mastectomy for some patients.

CONCLUSIONS

Systemic chemotherapy should be the mainstay of treatment. Based on our experience and a review of the literature, the use of Wiseman and Liao's classification is questionable. In fact, it fails to detect whether some lymphomas of the breast present a specific natural history and therefore require specific management. New clinical and histologic criteria are to be identified.

Immunohistochemical characterization of estrogen and progesterone receptors in lymphoma of horses

Immunohistochemical techniques were used to examine 29 cases of equine lymphoma for estrogen receptor (ER) and progesterone receptor (PR) expression. The lymphomas examined included T-cell-rich large B-cell lymphomas, B-cell neoplasms, and T-cell lymphomas. The individual cases were also classified according to the anatomic location of the tumors. One normal equine lymph node was also examined for ER and PR expression. All of the cases of equine lymphoma and the normal lymph node were negative for Er. A total of 16/29 (55%) PR-positive lymphomas were identified. Seven of the 12 (58%) T-cell-rich large B-cell lymphomas were positive, 7/11 (64%) B-cell tumors were positive, and 2/6 (33%) T-cell neoplasms were positive. Anatomically, 6/9 (66%) subcutaneous lymphomas were PR positive, 3/5 (60%) intrathoracic lymphomas were positive, 1/4 (25%) intra-abdominal lymphomas were positive, 2/5 (40%) intra-abdominal/intrathoracic lymphomas were positive, 1/2 (50%) upper airway lymphomas were positive, and 3/3 (100%) splenic lymphomas were positive. One case involving abdominal and thoracic tumors and leukemia was negative for PR expression. The normal lymph node contained a low percentage (1.9%) of PR-positive lymphocytes. The presence of PR in neoplastic equine lymphoid tissue indicates that these tumors may be responsive to serum progesterone. Also, identification of PR-positive cells in the normal lymph node suggests that PR may be constitutively expressed in normal equine lymphocytes. Further studies are needed to quantify PR levels in normal and malignant equine lymphoid tissue and to determine the usefulness of either progestin or antiprogestin drugs in the management of equine lymphoma.

Tamoxifen increases photodynamic therapeutic response of U87 and U25ln human glioma cells

We tested the hypothesis that Tamoxifen (TMX), an inhibitor of protein kinase C (PKC), augments the cytotoxicity of photodynamic therapy (PDT) treatment of human (U87) and (U25ln) glioma cells. U87 and U25ln glioma cells were plated and treated with PDT using Photofrin as the sensitizer. Cells were treated with Photofrin at various doses and with various optical (632 nm) irradiation intensities 24 h later. Cells were also treated with Photofrin at a fixed dose alone and with various doses of Tamoxifen and subjected to laser treatment 24 h later. Tumor response was tested using the (3-94,5-dimethyl-2-yl)-2,5-diphenyl-tetrazolium (MTT) method. Total toxicity of U87 cells was achieved with PDT at all doses of Photofrin (1, 2.5, 5, 10 microg/ml) with irradiation densities equal to or greater than 200 mJ/cm2. Using an irradiation intensity of 100 mJ/cm2, U87 and U25ln cells were killed in a Photofrin dose-dependent manner. Significant cytotoxicity was detected with Photofrin doses of 5 microg/ml (p < 0.05) and 10 microg/ml (p < 0.001). Tamoxifen at a dose of 500 microg/ml and higher, significantly increased the toxicity of the PDT response with 5 microg/ml Photofrin and 100 mJ/cm2 (p < 0.05). In summary, our data demonstrate that Tamoxifen significantly enhances the Photofrin PDT activity of U87 and U25ln human glioma cells.

Anti-Estrogens Induce Apoptosis of Multiple Myeloma Cells

Previous studies have suggested that multiple myeloma (MM) cells express estrogen receptors (ER). In the present study, we characterized the effects of estrogen agonists and antagonists (anti-estrogens [AE]) on growth of MM cell lines and MM patient cells. In addition to antagonizing estrogen binding to ER, AE can trigger apoptosis. Hence, we also determined whether estrogens or AE altered MM cell survival. Immunoblotting showed that ER- is expressed in 4 of 5 MM cell lines (ARH-77, RPMI 8226, S6B45, and U266, but not OCI-My-5 cells), as well as in freshly isolated MM cells from 3 of 3 patients. 17β-estradiol (E2) did not significantly alter proliferation of MM cell lines or MM patient cells. In contrast, two structurally distinct AE, tamoxifen (TAM) and ICI 182,780 (ICI), significantly inhibited the proliferation of all 5 MM cell lines and MM cells from 2 of 2 patients (IC50, 2 to 4 μmol/L). Proliferation of these cell lines was also inhibited by the hydroxylated TAM derivative, 4-hydroxytamoxifen (4HTAM), although this derivative was less potent than TAM (IC50, 3 to 25 μmol/L). In contrast, the dehalogenated TAM derivative toremifene (TOR) did not inhibit MM cell proliferation. We next examined the effects of these agents on MM cell survival. TAM, ICI, and, to a lesser extent, 4HTAM and TOR triggered apoptosis in both ER-–positive as well as ER-–negative MM cell lines and patient MM cells, evidenced both by fluorescence-activated cell sorting (FACS) analysis using propidium iodide staining and the TUNEL assay. TAM-induced growth inhibition and apoptosis of ER-–positive S6B45 MM cells was not blocked by coculture with excess E2. TAM-induced apoptosis of S6B45 MM cells was also unaffected by addition of exogenous interleukin-6. Importantly, both the inhibition of MM cell proliferation and the induction of MM cell apoptosis were achieved at concentrations of TAM (0.5 and 5.0 μmol/L) that did not significantly alter in vitro growth of normal hematopoietic progenitor cells. Similar plasma levels of TAM have been achieved using high-dose oral TAM therapy, with an acceptable toxicity profile. These studies therefore provide the rationale for trials to define the utility of AE therapy in MM.

© 1998 by The American Society of Hematology.

Anti-Estrogens Induce Apoptosis of Multiple Myeloma Cells

Previous studies have suggested that multiple myeloma (MM) cells express estrogen receptors (ER). In the present study, we characterized the effects of estrogen agonists and antagonists (anti-estrogens [AE]) on growth of MM cell lines and MM patient cells. In addition to antagonizing estrogen binding to ER, AE can trigger apoptosis. Hence, we also determined whether estrogens or AE altered MM cell survival. Immunoblotting showed that ER- is expressed in 4 of 5 MM cell lines (ARH-77, RPMI 8226, S6B45, and U266, but not OCI-My-5 cells), as well as in freshly isolated MM cells from 3 of 3 patients. 17β-estradiol (E2) did not significantly alter proliferation of MM cell lines or MM patient cells. In contrast, two structurally distinct AE, tamoxifen (TAM) and ICI 182,780 (ICI), significantly inhibited the proliferation of all 5 MM cell lines and MM cells from 2 of 2 patients (IC50, 2 to 4 μmol/L). Proliferation of these cell lines was also inhibited by the hydroxylated TAM derivative, 4-hydroxytamoxifen (4HTAM), although this derivative was less potent than TAM (IC50, 3 to 25 μmol/L). In contrast, the dehalogenated TAM derivative toremifene (TOR) did not inhibit MM cell proliferation. We next examined the effects of these agents on MM cell survival. TAM, ICI, and, to a lesser extent, 4HTAM and TOR triggered apoptosis in both ER-–positive as well as ER-–negative MM cell lines and patient MM cells, evidenced both by fluorescence-activated cell sorting (FACS) analysis using propidium iodide staining and the TUNEL assay. TAM-induced growth inhibition and apoptosis of ER-–positive S6B45 MM cells was not blocked by coculture with excess E2. TAM-induced apoptosis of S6B45 MM cells was also unaffected by addition of exogenous interleukin-6. Importantly, both the inhibition of MM cell proliferation and the induction of MM cell apoptosis were achieved at concentrations of TAM (0.5 and 5.0 μmol/L) that did not significantly alter in vitro growth of normal hematopoietic progenitor cells. Similar plasma levels of TAM have been achieved using high-dose oral TAM therapy, with an acceptable toxicity profile. These studies therefore provide the rationale for trials to define the utility of AE therapy in MM.

© 1998 by The American Society of Hematology.

Inhibition of the membrane translocation and activation of protein kinase C, and potentiation of doxorubicin-induced apoptosis of hepatocellular carcinoma cells by tamoxifen

Hepatocellular carcinoma (HCC) is characterized by high drug resistance to currently available chemotherapeutic agents. In a prospective clinical study, we have demonstrated that high-dose tamoxifen significantly enhanced the therapeutic efficacy of doxorubicin in patients with far-advanced HCC. In a search for a possible mechanism, we found that tamoxifen at a clinically achievable concentration (2.5 microM) significantly enhanced doxorubicin-induced cytotoxicity and apoptosis of Hep-3B cells, a multidrug resistance (MDR)-1 expressing HCC cell line. This synergistic cytotoxic effect of tamoxifen, at this concentration, however, was not mediated by MDR inhibition. Instead, as evidenced by both western blot and immunofluorescence studies, tamoxifen inhibited the cytoplasmic-membrane translocation of protein kinase C (PKC)-alpha. 12-O-Tetradecanoylphorbol-13-acetate (TPA) restored the membrane translocation of PKC-alpha and abrogated the synergistic cytotoxicity of tamoxifen. We also showed that tamoxifen, at this concentration, did not directly affect the enzyme activity of PKC. Further, membrane translocation of other membrane-bound proteins, such as Ras protein, was similarly inhibited by tamoxifen, but could not be restored by the addition of TPA. Together, these data suggested that tamoxifen may act on the cytoplasmic membrane, and thereby inhibit PKC-alpha translocation to the membrane where it is activated. We hypothesize that high-dose tamoxifen may be an effective modulator of doxorubicin in the treatment of HCC, and suggest that biochemical modulation of PKC as a measure to improve systemic chemotherapy for HCC deserves further investigation.

Endocrine characterization of primary mediastinal lymphoma

Because of the characteristic presentation of primary mediastinal large cell lymphoma (PMLCL) in young females its known origin from thymic B-cells, there might be a role in lymphomagenesis for estrogen receptors as well as for known neuroendocrine thymic mediators. A retrospective review of all patients with diffuse large cell lymphoma seen at our institution from January 1985 to January 1994 revealed 75 consecutive cases with a diagnosis of PMLCL. Through retrieval from our pathologic archives and requests to outside pathologists, we recovered and analyzed 17 biopsy specimens for the presence of the following hormone receptors: estrogen, beta endorphin, prolactin, T3, growth hormone, and leutinizing hormone. None of the specimens stained for any of the reagents. The most plausible explanation is that PMLCL tissues are devoid of these hormonal receptors and thus these receptors do not seem to play a role in the pathogenesis of PMLCL.

Primary non-Hodgkin's lymphomas of the female breast

The charts of 35 women with primary malignant non-Hodgkin's lymphomas (NHL) of the breast were retrieved from the files of the Istituto Nazionale Tumori, Milan, over a 30-year period (1957 to 1986). These cases represented 0.1% of the more than 25,000 primary malignant tumors of the breast treated during the same period. The median age of these patients was 57 years (range, 28 to 81 years). In most cases, the clinical diagnosis was carcinoma. The tumors were either Stage IE(48%) or IIE(52%) at presentation, and only two patients had B symptoms. The right breast was involved in 17 patients, the left breast in 14, and both breasts in two. According to the updated Kiel classification and the Working Formulation (WF) for Clinical Usage, three cases were lymphoplasmacytoid (immunocytoma) NHL (WF, A); three, centroblastic-centrocytic, follicular NHL (WF, B); four, centroblastic-centrocytic, diffuse NHL (WF, F); 17 centroblastic NHL (WF, G); three immunoblastic NHL (WF, H); two B-lymphoblastic NHL (WF, I); and one, a Burkitt-like NHL (WF, J). Treatment consisted either of a combination of surgery, radiation therapy, and chemotherapy or radiation therapy and chemotherapy. The follow-up period for 32 patients ranged from 6 to 161 months (mean, 45 months); 17 patients died of their disease. The prognosis appeared to be related to the histologic type and stage of the disease. Median survival periods were 63, 52, 42, and 47 months for centroblastic-centrocytic follicular, centroblastic-centrocytic diffuse, centroblastic, and immunoblastic NHL, respectively. The overall 5-year survival rate was 43%; the 5-year survival rate and the probability of freedom from progression at 5 years were, respectively, 61% and 50% for Stage I and 27% and 26% for Stage II disease.

Improvement in the POEMS syndrome after administration of tamoxifen

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Immunocytochemical identification of nuclear estrogen-receptors in human acute myeloid leukemia

The peripheral and bone marrow blast cells of twenty patients newly-diagnosed as acute myeloid leukemia (AML), subtypes M1-M5, were analysed for the presence of estrogen-receptors by ER-ICA immunocytochemistry and dextran-coated charcoal cytosolic (DCC) assay. Two patients demonstrated myeloblasts with nuclear staining patterns consistent with the presence of estrogen-receptors. The positive immuno-staining results were confirmed by DCC in one patient with AML, subtype M4. This patient demonstrated an unusual myeloblast karyotype with a reciprocal translocation t(6;11)(q27;q23.3) involving the designated locus of the ESR gene on chromosome 6 (6q24-qter). The abnormal juxtaposition of DNA control elements close to the promoter of the ESR gene may be one mechanism by which aberrant synthesis of estrogen-receptor protein can occur to provide a growth advantage for leukemia cell clones.

Fatty acid modulation of antiestrogen action and antiestrogen-binding protein in cultured lymphoid cells

Nonsteroidal antiestrogens reversibly and specifically inhibited the proliferation of two estrogen receptor-negative lymphoid cell lines (EL4 and Raji) in a dose-dependent manner. [3H]Thymidine incorporation of concanavalin A-stimulated primary splenocytes was also inhibited by 10(-6) M clomiphene (1-[4-(2-diethylaminoethoxy)phenyl]-1,2-diphenyl-2-chloroethylene). The antiproliferative effect could be prevented by the simultaneous presence in the growth medium of 10(-5) M linoleic acid or 10(-5) M arachidonic acid but not by 10(-6) M estradiol. Both lymphoid cell lines had high affinity antiestrogen-binding sites whose affinity could be altered by conditions of growth. Growth of EL4 cells in RPMI 1640 medium supplemented with charcoal-pretreated 5% fetal calf serum (charcoal-stripped medium) resulted in significantly higher affinity (Kd 0.54 nM +/- 0.11 nM; n = 6) than growth in medium supplemented with untreated serum (complete medium) (Kd = 1.68 nM +/- 0.48 nM; n = 6) (p less than 0.001). This change in affinity was partly due to removal of fatty acids from the growth medium by charcoal pretreatment, since addition of 10(-5) M linoleic acid or 10(-5) M gamma-linolenic to charcoal-stripped medium decreased the affinity of the antiestrogen-binding protein. In contrast, growth in 10(-5) M stearic acid or 10(-5) M oleic acid did not significantly alter the affinity of the antiestrogen-binding protein, whereas 10(-5) M palmitic acid significantly increased its affinity. The same fatty acids were also tested for their intrinsic effects on EL4 cell proliferation. Oleic, linoleic and gamma-linolenic acids were growth stimulatory while stearic and palmitic acids were not. Thus linoleic and gamma-linolenic acids whose presence in the growth medium was associated with decreased affinity of [3H]tamoxifen (1-[4-(2-dimethylaminoethoxy)phenyl]-1,2-diphenylbut-1(Z)-ene) binding to the intracellular antiestrogen-binding protein were also growth stimulatory. Unsaturated fatty acids have previously been shown to inhibit binding of [3H]tamoxifen to the antiestrogen-binding protein in a cell-free system. The present observations demonstrate that unsaturated fatty acids also modify the affinity of the antiestrogen-binding protein in intact cells.

Spontaneous remission of acute leukemia after the termination of pregnancy

A 28-year-old woman in the third trimester of her pregnancy was found to have acute myelocytic leukemia. The baby was delivered by Cesarean section and her leukemia underwent spontaneous remission. However, 3 months later, she presented with massive painful leukemic infiltration of the breasts as initial manifestation of relapse, followed by systemic symptoms of leukemia. In vitro culture of the leukemic cells demonstrated characteristics of macrophage cell line. This case illustrates a unique sequence of events: spontaneous remission after the termination of pregnancy, which has profound hormonal alterations, and relapse in a very hormone-sensitive organ, the breast, a few months later when the hormonal milieu was resumed. This suggests hormonal dependence of her leukemic cells and potential for hormonal manipulation in a certain subset of human leukemia.

Combined effects of interferon and steroid hormones on 2',5'-oligoadenylate synthetase activity in chronic lymphocytic leukemia cells

2',5'-oligoadenylate synthetase (OAS) has been implicated in the effects of interferons (INF) and steroid hormones on cell growth and differentiation. We studied the combined effects in vitro of hormones and INF on OAS activity in cells from 10 patients with chronic lymphocytic leukemia. IFN enhanced OAS activity in all cells studied and also induced morphologic transformation. Diethylstilbestrol was also found to induce OAS activity, but not morphologic transformation. Progesterone, tamoxifen and dihydrotestosterone had no effect on enzyme activity nor on morphology. In five samples, all with estrogen receptor activity, DES and INF were synergistic in inducing OAS activity. TAM-INF synergism was observed in one sample. DES and TAM did not, however, significantly enhance IFN-induced morphologic transformations. Hydrocortisone reduced OAS activity, and antagonized INF-induced enzyme activity and morphologic transformations. We conclude that hormones can modulate OAS activity in CLL cells. These findings may be of importance in the design of INF-based therapies of CLL.

Histiocytic lymphoma of breast responds to tamoxifen

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