Pulmonary Metastatic Foci Research Articles

CCL3 and CCL20-recruited dendritic cells modified by melanoma antigen gene-1 induce anti-tumor immunity against gastric cancer ex vivo and in vivo.

BackgroundTo investigate whether dendritic cell (DC) precursors, recruited by injection of chemokine ligand 3 (CCL3) and CCL20, induce anti-tumor immunity against gastric cancer induced by a DC vaccine expressing melanoma antigen gene-1 (MAGE-1) ex vivo and in vivo.MethodsB6 mice were injected with CCL3 and CCL20 via the tail vein. Freshly isolated F4/80-B220-CD11c+ cells cultured with cytokines were analyzed by phenotype analysis and mixed lymphocyte reaction (MLR). For adenoviral (Ad)-mediated gene transduction, cultured F4/80-B220-CD11c+ cells were incubated with Ad-MAGE-1. Vaccination of stimulated DC induced T lymphocytes. The killing effect of these T cells against gastric carcinoma cells was assayed by MTT. INF-γ production was determined with an INF-γ ELISA kit. In the solid tumor and metastases model, DC-based vaccines were used for immunization after challenge with MFC cells. Tumor size, survival of mice, and number of pulmonary metastatic foci were used to assess the therapeutic effect of DC vaccines.ResultsF4/80-B220-CD11c+ cell numbers increased after CCL3 and CCL20 injection. Freshly isolated F4/80-B220-CD11c+ cells cultured with cytokines were phenotyically identical to typical DC and gained the capacity to stimulate allogeneic T cells. These DCs were transduced with Ad-MAGE-1, which were prepared for DC vaccines expressing tumor antigen. T lymphocytes stimulated by DCs transduced with Ad-MAGE-1 exhibited specific killing effects on gastric carcinoma cells and produced high levels of INF-γ ex vivo. In vivo, tumor sizes of the experimental group were much smaller than both the positive control group and the negative control groups (P < 0.05). Kaplan-Meier survival curves showed that survival of the experimental group mice was significantly longer than the control groups (P < 0.05). In addition, MAGE-1-transduced DCs were also a therapeutic benefit on an established metastatic tumor, resulting in a tremendous decrease in the number of pulmonary metastatic foci.ConclusionsCCL3 and CCL20-recruited DCs modified by adenovirus-trasnsduced, tumor-associated antigen, MAGE-1, can stimulate anti-tumor immunity specific to gastric cancer ex vivo and in vivo. This system may prove to be an efficient strategy for anti-tumor immunotherapy.

Fumagillin inhibits colorectal cancer growth and metastasis in mice: In vivo and in vitro study of anti‐angiogenesis

Fumagillin is an inhibitor of type 2 methionine aminopeptidase that can block blood vessel formation, but its molecular mechanism and therapeutic value in colon cancer still remain to be elucidated. In this study, male severe combined immunodeficiency (SCID) mice were injected with colon cancer cells in the subcutis and then treated with Fumagillin and Cyclo (Arg-Gly-Asp-D-Phe-Val), an integrin alphavbeta(3) antagonist. The tumor weight, microvessel density (MVD), and number of pulmonary metastatic foci were examined. Gene expression profiles were examined by microarray analysis of human umbilical endothelial cells (HUVEC). The Fumagillin-treated mice had smaller tumor mass, fewer pulmonary metastases, and lower MVD-CD105 levels than control animals. In vitro proliferation and tube formation of HUVEC was also significantly decreased by Fumagillin. Microarray analysis of Fumagillin-treated HUVEC showed upregulation of 71 genes and downregulation of 143 genes. Expression changes were involved in cell proliferation, migration, adhesion, and gene transcription. Quantitative real-time-polymerase chain reaction and western blotting showed decreased expression of cyclin E2, activated leukocyte cell adhesion molecule (ALCAM), and intercellular adhesion molecule-1 (ICAM-1) genes in the presence of Fumagillin. This downregulation by Fumagillin may be involved in the anti-angiogenesis by Fumagillin. In conclusion, Fumagillin was found to suppress colorectal cancer growth and metastasis by suppressing angiogenesis.

Novel Anti-Metastatic Action of Cidofovir Mediated by Inhibition of E6/E7, CXCR4 and Rho/ROCK Signaling in HPV+ Tumor Cells

Cervical cancer is frequently associated with HPV infection. The expression of E6 and E7 HPV oncoproteins is a key factor in its carcinogenicity and might also influence its virulence, including metastatic conversion. The cellular mechanisms involved in metastatic spread remain elusive, but pro-adhesive receptors and their ligands, such as SDF-1α and CXCR4 are implicated. In the present study, we assessed the possible relationship between SDF-1α/CXCR4 signaling, E6/E7 status and the metastatic process. We found that SDF-1α stimulated the invasion of E6/E7-positive cancer cell lines (HeLa and TC-1) in Matrigel though CXCR4 and subsequent Rho/ROCK activation. In pulmonary metastatic foci generated by TC-1 cells IV injection a high proportion of cells expressed membrane-associated CXCR4. In both cases models (in vitro and in vivo) cell adhesion and invasion was abrogated by CXCR4 immunological blockade supporting a contribution of SDF-1α/CXCR4 to the metastatic process. E6 and E7 silencing using stable knock-down and the approved anti-viral agent, Cidofovir decreased CXCR4 gene expression as well as both, constitutive and SDF-1α-induced cell invasion. In addition, Cidofovir inhibited lung metastasis (both adhesion and invasion) supporting contribution of E6 and E7 oncoproteins to the metastatic process. Finally, potential signals activated downstream SDF-1α/CXCR4 and involved in lung homing of E6/E7-expressing tumor cells were investigated. The contribution of the Rho/ROCK pathway was suggested by the inhibitory effect triggered by Cidofovir and further confirmed using Y-27632 (a small molecule ROCK inhibitor). These data suggest a novel and highly translatable therapeutic approach to cervix cancer, by inhibition of adhesion and invasion of circulating HPV-positive tumor cells, using Cidofovir and/or ROCK inhibition.

NK4, an HGF antagonist, prevents hematogenous pulmonary metastasis by inhibiting adhesion of CT26 cells to endothelial cells

Hepatocyte growth factor (HGF) plays a definitive role in invasive, angiogenic, and metastatic activities of tumor cells by binding to the c-Met receptor. NK4, a competitive antagonist for HGF and the c-Met receptor, prevents tumor cell growth and metastasis via its bifunctional properties to act as an HGF antagonist and angiogenesis inhibitor. In the present study, we investigated the inhibitory effectiveness of NK4 on hematogenous pulmonary metastasis of the CT26 murine colon cancer cell line, focusing on tumor cell adhesion to endothelial cells. In an in vitro adhesion assay, HGF facilitated adhesion of CT26 cells to a murine endothelial cell line (F-2) in a dose-dependent manner. Furthermore, the enhancing effect of HGF on CT26-F-2 cell interaction was blocked by NK4 as well as by anti-HGF antibody. Similarly, HGF-induced phosphorylation of focal adhesion kinase (FAK), downstream of integrin signaling, was reduced by NK4 and by anti-HGF antibody. However, distinct integrin expression on the surface of CT26 cells was not altered by HGF. In an in vivo experimental pulmonary metastasis assay, stable NK4 expression potently decreased the number of pulmonary metastatic foci. The NK4-induced suppression of pulmonary metastasis was partially reversed when HGF was intraperitoneally administered in an adhesive phase. These results suggest that NK4 could act on tumor cells to inhibit CT26 adhesion to endothelial cells by reducing FAK phosphorylation, which is regulated by inside-out HGF/c-Met signaling, and thereby suppress hematogenous pulmonary metastasis.

Costimulatory strength influences the differential effects of transforming growth factor β1 for the generation of CD8 + regulatory T cells

Transforming growth factor β1 (TGFβ1) is a pleiotropic cytokine, capable of exerting diverse biologic effects. Despite its central role in multiple immune activities, the molecular signals responsible for shaping TGFβ1's immunologic properties remain poorly elucidated. We report that costimulatory strength acts as a molecular switch, which influences the differential effects of TGFβ1 on the effector and regulatory development of naïve CD8 + lymphocytes. At low costimulation, TGFβ1 inhibits proliferation of CD8 + lymphocytes and cytokine secretion, but at high costimulation the response to TGFβ1 is quite different. High costimulation combined with TGFβ1 generates CD8 +CD25 + T lymphocytes which maintain robust proliferative and survival capacity in the presence of low IL-2 concentrations. Furthermore, under these conditions, a subpopulation of CD8 + T lymphocytes is generated that express Foxp3, secrete IL-10, and inhibit naïve T lymphocyte proliferation via a contact-dependent mechanism. The adoptive transfer of these CD8 +CD25 + Foxp3 + T cells into mice inoculated intravenously with B16F10 melanoma appears to accelerate tumor progression as reflected by an increase in the number of pulmonary metastatic tumor foci. These findings indicate that costimulatory strength may act as a molecular switch in the generation of CD8 + T cells which possess a regulatory phenotype and the capacity to reduce antitumor immune responses within tumor-bearing mice.

Successful management of life‐threatening choriocarcinoma syndrome with rupture of pulmonary metastatic foci causing hemorrhagic shock

We report a case of a man with testicular cancer metastatic to the lung and retroperitoneal lymph node, with significant elevation of serum levels of human chorionic gonadotropin, 534,000 mIU/mL. Just after the initiation of chemotherapy, life-threatening hemothorax occurred and hemorrhagic shock ensued. The pulmonary tumor had broken off, and lower lobectomy was carried out. Pathologic examination of the specimen revealed choriocarcinoma and yolk sac tumor. Through multimodal treatments he achieved complete remission. To our knowledge, this is the first case report of choriocarcinoma syndrome with life-threatening hemorrhage caused by rupture of pulmonary metastases, resulting in complete remission through multimodal treatments.

Enhanced suppression of pulmonary metastasis of malignant melanoma cells by combined administration of α‐galactosylceramide and interleukin‐18

alpha-Galactosylceramide (alpha-GalCer) shows antitumor effects by activating natural killer (NK) cells indirectly through stimulation of the secretion of cytokines by NKT cells, whereas interleukin (IL)-18 shows antitumor effects by activating NK cells directly. In the present study, we examined the antitumor effect of the combined administration of alpha-GalCer and IL-18. An injection of NK cell-sensitive mouse B16 melanoma cells into a mouse tail vein produced pulmonary metastasis. The daily administration of alpha-GalCer or IL-18 alone for 4 days starting 1 day after the injection of B16 melanoma cells markedly suppressed the number of pulmonary metastatic foci, and their combined administration enhanced the antitumor effect compared with single administration. The antitumor effect of their combined administration was completely abolished by treatment of mice with anti-asialo GM1 serum, which depletes NK cells but not NKT cells. Combined administration of alpha-GalCer and IL-18 enhanced the cytotoxicity of NK cells and increased the number of NK cells in the lung. Analysis of NKT cell-dependent and NK cell-independent secretion of cytokines, to which NK cells can respond, showed that the administration of alpha-GalCer increased the secretion of IL-2, IL-4, interferon-gamma, IL-12, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, and IL-10, and the combined administration of alpha-GalCer and IL-18 enhanced the secretion of IL-2, IL-4, interferon-gamma, and granulocyte-macrophage colony-stimulating factor further but only slightly. These results show that IL-18 in combination with alpha-GalCer exerts an antitumor effect on NK cell-sensitive tumors primarily by the direct stimulation of NK cells by IL-18 and the indirect stimulation of NK cells by alpha-GalCer through its activation of NKT cells.

Role of von Willebrand factor in tumor metastasis

Von Willebrand factor (VWF) is a multimeric plasma glycoprotein that plays a critical role in primary hemostasis, allowing the adhesion of platelets to the exposed subendothelium. The key role played by VWF in platelet adhesion suggests a potential implication in various pathologies where this process is involved. In cancer metastasis development, tumor cells interact with platelets and the vessel wall to extravasate from the circulation. A number of potential receptors for VWF have been identified on tumor cells such as glycoprotein Ib or the α IIbβ 3 and α vβ 3 integrins and direct interactions between VWF and tumor cells have been reported. To address the role of VWF in an experimental metastasis model, we compared the formation of pulmonary metastatic foci in C57BL/6J wild-type and VWF-null mice following I.V. injection of murine melanoma B16-BL6 cells or Lewis lung carcinoma cells. Surprisingly we found a significant increase in the number of pulmonary metastatic foci in VWF-null mice. Restoration of VWF plasma levels by co-injection of VWF with the tumor cells led to the correction of this pro-metastatic phenotype. In vitro analysis revealed that VWF did not influence tumor cell proliferation or invasion but induced cellular death. This result was confirmed in vivo where analysis of the early survival of tumor cells in the lungs revealed that the presence of VWF led to a decreased survival of these cells during the first 24 hours after injection. Our results suggest that VWF plays a role in tumor metastasis, independently of its role in hemostasis.

Suppression of Atopic Dermatitis and Tumor Metastasis in Mice by Small Amounts of Radon

We examined the effect of radon in two experimental disease models in mice by administering radon dissolved in water at 68-203 Bq/liter. Administration of radon in drinking water to NC/Nga mice significantly delayed the progression of atopic dermatitis-like skin lesions induced by picrylchloride when administered prior to the induction of disease signs. The number of pulmonary metastatic foci in C57BL/6 mice inoculated with B16 melanoma cells was also reduced significantly by administration of radon in drinking water when the number of tumor cells was small and the radon treatment was started prior to tumor inoculation. The ratio of Ifng to Il4 produced by splenocytes from BALB/c mice immunized with DNP-Ascaris was significantly increased by administration of radon in drinking water. From these results, a modulation of immunity by radon was suggested.

L-Selectin Facilitation of Metastasis Involves Temporal Induction ofFut7-Dependent Ligands at Sites of Tumor Cell Arrest

Hematogenous carcinoma metastasis is supported by aggregated platelets and leukocytes, forming tumor cell emboli. Early tumor cell-platelet interactions can be mediated by P-selectin binding to tumor cell surface ligands and this process is blocked by heparin. We previously showed that L-selectin deficiency also attenuates experimental metastasis. However, the mechanisms and timing of L-selectin action remained unknown. Here, we study how L-selectin facilitates establishment of pulmonary metastatic foci in syngeneic mice by using experimental metastasis to time events following entry of tumor cells into the bloodstream. Although L-selectin deficiency did not affect platelet aggregation or initial tumor cell embolization, the association of leukocytes with tumor cells was reduced and tumor cell survival was diminished 24 hours later. Temporal inhibition of L-selectin by a function-blocking antibody reduced metastasis. Moreover, although selectin blockade by heparin 6 to 18 hours after tumor cell injection was synergistic with P-selectin deficiency in reducing metastasis, there was no further effect in L-selectin-deficient animals. Thus, heparin apparently works at these time points primarily by blocking L-selectin. Endogenous L-selectin ligands were concomitantly induced adjacent to established intravascular tumor cell emboli in a similar time window when leukocytes were also present. Metastasis was attenuated in mice missing these induced endogenous L-selectin ligands due to fucosyltransferase-7 deficiency. Thus, L-selectin facilitation of metastasis progression involves leukocyte-endothelial interactions at sites of intravascular arrest supported by local induction of L-selectin ligands via fucosyltransferase-7. These data provide the first explanation for how leukocyte L-selectin facilitates tumor metastasis.

Effect of interleukin-18 on metastasis of mouse osteosarcoma cells.

The effect of interleukin-18 (IL-18) on metastasis of highly metastatic LM8 mouse osteosarcoma cells was investigated using nude mice treated with anti-asialo GM1 serum to exclude anti-tumor actions of IL-18 through activation of T and natural killer cells. Injection of LM8 cells which do not express IL-18 receptor beta into a tail vain resulted in the formation of pulmonary and hepatic metastatic foci. Daily injection of mice with IL-18 starting the fifth day from the cell injection had no significant effect on the number of metastatic foci, while five daily injections of IL-18 before and after the cell injection resulted in marked decreases. Culture of LM8 cells with IL-18 for 5 days before the injection into mice produced no significant effect on the number of pulmonary and hepatic metastatic foci. In contrast, pretreatment of mice with IL-18 for 5 days before the cell injection markedly decreased metastatic foci. The retention of LM8 cells in the lung 24 h after their injection was also reduced by the pretreatment of mice with IL-18. Serum obtained from mice pretreated with IL-18 for 5 days suppressed mobility of LM8 cells but IL-18 itself did not. These results suggest that IL-18 inhibits metastasis of LM8 cells partly by inducing a factor(s) in the host which suppresses cell mobility.

Characterization of Ocular and Metastatic Uveal Melanoma in an Animal Model

To characterize, in detail, tumor development, malignant cell dissemination, and metastasis in a 10-week animal model of uveal melanoma. One million 92.1 human primary uveal melanoma cells were injected into the suprachoroidal space of the right eye of 27 immunosuppressed albino rabbits. Intraocular tumor growth was monitored weekly by fundoscopy and by ultrasonography at the end of the experiment. To document the progression of the disease, one animal per week was killed. The enucleated eyes, lungs, and livers were macroscopically examined and histopathologically studied by hematoxylin and eosin, periodic acid-Schiff, and immunohistochemistry. Mononuclear layers isolated from the rabbits' blood samples were cultured. Histopathology showed intraocular tumors in 89% of the animals. Tumor growth was found 1 week after cell inoculation, and by the end of the experiment large tumor masses were observed. Microscopic pulmonary metastatic foci were first observed 4 weeks after cell injection. By the end of the experiment, all the animals had metastasis to the lungs. Interestingly, 18% of the animals also had micrometastasis to the liver. Viable adherent uveal melanoma cells were successfully isolated from peripheral blood and grown in vitro. In this study, most rabbits developed intraocular tumors followed by lung metastasis, and some of these rabbits later developed liver micrometastases. This novel source of research material warrants a follow-up longer than 10 weeks to further explore the pathophysiologic bases of liver involvement commonly encountered in humans. The success in the isolation and culture of circulating malignant cells in this animal model suggests that it might be worthwhile to explore the application of this technique to the management of patients with primary uveal melanoma.

Hemostatic Factors Contribute to Tumor Cell Metastatic Potential by a Mechanism Linked to Natural Killer Cell Function.

A linkage between hemostatic system components and tumor cell metastatic potential has been well established, but the underlying mechanism(s) by which various circulating and cell-associated coagulation factors and platelets promote tumor cell dissemination remains to be fully defined. One potential mechanism by which tumor cell-associated microthrombi might enhance metastatic potential is by interfering with the cytolytic elimination of tumor cell emboli by natural killer (NK) cells. In order to explore this hypothesis, we studied tumor dissemination in mice lacking either fibrinogen or Gαq, a G protein critical for platelet activation. Comparative studies of experimental lung metastasis in control and Gαq−/− mice showed that loss of platelet activation resulted in a two-orders-of-magnitude decrease in pulmonary metastatic foci formed by either Lewis lung carcinoma or B16 melanoma. The difference in metastatic success was not the result of differences in tumor growth rate, as tumors transplanted into the dorsal subcutis of Gαq−/− and wildtype animals grew at similar rates. Rather, tumor cell fate analyses using radiolabeled tumor cells showed that the survival of tumor cells within the lung was significantly improved in mice that retained platelet activation function relative to Gαq−/− mice with a profound platelet activation defect. In order to examine the potential interplay between platelet activation and natural killer cell function, we compared pulmonary tumor cell survival in cohorts of control and Gαq−/− mice immuno-depleted of NK cells with an anti-asialo GM1 antibody. Remarkably, platelet function was no longer a determinant of metastatic potential in mice lacking NK cells. Given that fibrin(ogen) is also an established determinant of metastatic success we explored whether the influence of this key hemostatic factor on tumor cell dissemination was also mechanistically-coupled to natural killer cell function. We interbred fibrinogen-deficient mice with Gz-Ly49A transgenic mice known to have a constitutive deficit in NK cells. In those cohorts of mice with normal NK cells, we affirmed the earlier finding that fibrinogen deficiency resulted in a significant diminution in metastatic potential. However, consistent with our findings in mice with defective platelet activation, fibrinogen was found to no longer be a determinant of metastatic potential in mice lacking NK cells. These data establish another important link between innate immune surveillance and the hemostatic system. Further, it appears that at least one mechanism by which tumor cell-associated microthrombi increase metastatic potential is by restricting NK cell-mediated tumor cell elimination. Given that NK cell cytotoxicity requires direct contact with any target cell, one attractive model presently being explored is that tumor cell-associated platelets physically block NK cell access to tumor cell emboli.

Preclinical antitumour activity of F 11782, a novel dual catalytic inhibitor of topoisomerases.

F 11782 is a novel inhibitor of topoisomerases I and II, with an original mechanism of action (Perrin et al, 2000). This study, aimed to define its anticancer efficacy against a series of murine and human tumour models, has provided evidence of major antitumour activity for F 11782. This was demonstrated as a high level of activity against the P388 leukaemia, as reflected by increased survival of 143–457%, when administered i.p., p.o. or i.v. as single or multiple doses, and proved consistently superior to etoposide or camptothecin tested concurrently. Single or multiple i.p. doses of F 11782 also proved highly active against the s.c. grafted B16 melanoma, significantly increasing survival (P < 0.001) and inhibiting tumour growth (T/C of 0.3%), again superior to etoposide tested concurrently. Furthermore, F 11782 inhibited the number of pulmonary metastatic foci of the B16F10 melanoma by 99%. In human tumour xenograft studies, multiple i.p. doses of F 11782 resulted in major inhibitory activity against MX-1 (breast) tumours (T/C of 0.1%), as well as causing definite tumour regressions, whereas none resulted from similar experimental treatments with etoposide. Significant activity was also recorded with F 11782 against the relatively refractory LX-1 (lung) xenografts, with an optimal T/C value of 19%. It was notable that the antitumour activity of F 11782 was consistently demonstrated over a wide range of 2–6 dose levels, providing evidence of its good overall tolerance. In conclusion, these results emphasize the preclinical interest of this novel molecule and support its further preclinical development. © 2000 Cancer Research Campaign http://www.bjcancer.com

Inhibitory Effect of Amiloride on the Urokinase Plasminogen Activators in Prostatic Cancer

The diuretic drug amiloride (AMLD), which competitively inhibits the catalytic activity of urokinase plasminogen activators (UPA), was used to study its effects on the proteolytic enzymes implicated in the invasiveness and metastases in a prostatic tumor model carrying two different sublines of adenocarcinoma of the prostate. Our data showed that UPA activity was significantly higher, both in the cytosol and pellet of R3327-AT3, a fast-growing highly metastatic and androgen-insensitive tumor, as compared to the G3327-G subline, a slow-growing nonmetastatic tumor of the prostate. The UPA activity in AT3 tumor dropped when the rats were treated with AMLD for 3 weeks. The UPA activity in the sera and tumor effusions from rats with AT3 tumor was significantly higher as compared to those with G subline tumor. The number of pulmonary metastatic foci was the same in untreated rats as compared to those treated with AMLD. The lymph node inspection after 3 weeks revealed no secondary tumor in the AMLD-treated group. The role of UPA in the metastases of prostate cancer is discussed.

The enhancement of tween-80 on the antitumor effect of the hyperthermia 41°C in tumor-bearing mice

B16 melanoma cells were inoculated into the BALB/C mice to establish melanoma-bearing models. The antitumor effect of Tween-80 in combination with hyperthermia 41°C was studied. We observed the changes of the mortality of tumor-bearing mice, the tumor growth curves, activities of serum tumor necrosis factor (STNF) and the level of serum sialic acid (SSA) in tumor-bearing mice. The number of pulmonary metastatic tumor foci from blood flow was also detected. The results showed that combined with Tween-80, hyperthermia 41 °C could dramatically suppress the growth of the melanoma in the feet of mice, survive the tumor-bearing mice and decrease the number of pulmonary metastatic tumor foci but no significant effects were observed by treatment with Tween-80 or hyperthermia at 41 °C alone. The activities of STNF and the level of SSA of the melanoma-bearing mice kept at higher levels than those of normal BALB/C mice. Tween-80 combined with heating 41°C significantly decreased activities of STNF, but the level of SSA still kept high level within 1 to 2 weeks and decreased 10 weeks later with the tumor regression. These results demonstrate that Tween-80 may make hyperthermia exert effective antitumor effect below the critical temperature and increase the safety of hyperthermia in treatment. It is one of the most ideal synergist with hyperthermia. The changes of STNF and SSA suggest that the synergetic effect could involve in facilitating the exposure of tumor antigen and activation of immune system.

Antitumor Effects of Angiogenesis Inhibitor O-(Chloroacetyl-Carbamoyl) Fumagillol (TNP-470) against Murine Renal Cell Carcinoma

Purpose The effect of 0-(chloroacetyl-carbamoyl) fumagillol (TNP-470) on tumor growth and metastasis is investigated. Materials and Methods BALB/c mice were inoculated with the Renca murine tumor and graded doses of TNP-470 were given subcutaneously every other day beginning on day 1 and ending on day 9. Tumor angiogenesis was measured quantitatively by a colorimetric assay. Results TNP-470 inhibited tumor growth and prolonged the life span of Renca-bearing mice in a dose-dependent manner. Body weight-loss was not observed in the mice given less than 30 mg./kg./day. When the treatment was delayed on day 6, TNP-470 did not inhibit tumor growth, pointing to the importance of the timing of drug administration in relation to disease stage. Tumor angiogenesis was inhibited 33 to 62 percent of the control level by TNP-470. Furthermore, TNP-470 reduced pulmonary and hepatic metastatic foci of intravenously inoculated Renca and of the tumor inoculated in the spleen. Conclusion These data suggest that TNP-470 may be effective as a treatment of renal cell carcinoma, especially when micrometastases are involved.

Antitumor response to recombinant murine interferon gamma correlates with enhanced immune function of organ-associated, but not recirculating cytolytic T lymphocytes and macrophages.

The mechanism of therapeutic activity for recombinant murine interferon-gamma (rMu IFN gamma) in the treatment of metastatic disease was investigated by comparing effector cell augmentation with therapeutic activity in mice bearing experimental lung metastases (B16-BL6 melanoma). Effector cell functions in spleen, peripheral blood, and lung (the tumor-bearing organ) were tested after 1 week and 3 weeks of rMu IFN gamma administration (i.v. three times per week). Natural killer (NK), lymphokine-activated killer (LAK), cytolytic T lymphocyte (CTL) activities against specific and nonspecific targets, and macrophage tumoristatic activity were measured. rMu IFN gamma demonstrated immunomodulatory activity in most assays of immune function. The optimal therapeutic protocol of rMu IFN gamma (2.5 x 10(6) U/kg, three times per week) prolonged survival and decreased the number of pulmonary metastatic foci. This therapeutic activity was correlated with specific CTL activity from pulmonary parenchymal mononuclear cells (PPMC), but not from spleen or blood. Macrophage tumoristatic activity in PPMC also correlated with therapeutic activity, but activity in alveolar macrophages did not. However, therapeutic activity did not correlate with NK or LAK activity at any site. These results demonstrate that the optimal therapeutic protocol is the same as the optimal immunomodulatory dose for pulmonary CTL and macrophage activities. Furthermore, while immunological monitoring may help to optimize treatment protocols, current monitoring procedures that use readily accessible sites, particularly peripheral blood, may not accurately predict the therapeutic efficacy of biological response modifiers in clinical trials.

Unusual Scintigraphic Findings of Synovial Sarcoma Metastases

Synovial cell sarcoma, which accounts for much less than 1% of all malignancies, arises from the cells associated with the synovium or the tendon sheath, bursa, or external capsule of the joint. The extremities' periarticular regions are commonly the primary site (94%). Synovial cell sarcoma affects young adults (mean age = 30) and usually spreads by the hematogenous route, while lymphatic spread is uncommon. At the time of initial diagnosis, the vast majority has no detectable distant metastases. However, if metastasis is present, 75% would develop in the lungs, 15% in the regional lymph nodes, 10% in bones. Metastases can appear as calcified nodules in 30–50% of cases. This case presents an unusual appearance of calcification in the right lower abdominal metastatic focus. In addition, calcification of the larger pulmonary metastatic foci were also visualized.

Osteosarcoma of the Patella

A 34-year-old woman complained of pain and swelling in the left patella. Because of roentgenogram showed hardly any destruction of the patella, she was not initially treated for a bone tumor. The clinical course followed the initial symptoms of a respiratory disorder with pulmonary metastatic foci. A bone tumor was first suspected after aspiration cytology of a lung tumor mass. A left patellectomy was performed to relieve the pain and confirm the diagnosis. The pain was relieved by the operation, but respiratory failure set in and progressed rapidly. The patient died three days later. Histologic examination showed that the tumor tissue consisted of atypical cells, spindle to polygonal in shape. The marrow space of the patella was predominantly occupied by neoplastic cartilaginous tissue. The pathologic diagnosis was primary chondroblastic osteosarcoma of the patella.