Intravenous Tumor Research Articles

Everolimus (RAD) Inhibits In Vivo Growth of Murine Squamous Cell Carcinoma (SCC VII)

Everolimus (RAD) is an mTOR inhibitor closely related to rapamycin. A potent immunosuppressive agent, it has also shown evidence of antineoplastic properties. SCC VII is a spontaneously arising murine squamous cell carcinoma line. This study examines the effect of everolimus on SCC VII proliferation. The data may provide support for the use of everolimus in transplant recipients with a history of malignancy. A dose efficacy study was conducted that used a murine model of intradermal tumor growth and pulmonary metastases. The development of intradermal tumors and pulmonary metastases were studied. Of 80 total mice, 40 received intradermal injection of 1 x 10 SCC VII cells and 40 received intravenous injection of 1 x 10 cells to establish pulmonary metastases. Within each group, animals were subdivided into four subgroups that received 1) 1 mg/kg everolimus twice a day, 2) 0.5 mg/kg everolimus twice a day, 3) 7.5 mg/kg cyclosporine per day, and 4) no treatment. Intradermal tumors were measured three times per week. Animals receiving an intravenous tumor injection were killed after 17 days and pulmonary metastases were quantified. Medication trough levels were measured in all treated animals. Everolimus showed statistically significant tumor inhibition at 1.0 mg/kg twice a day and 0.5 mg/kg twice a day when compared with animals treated with cyclosporine and with untreated animals (P < .0001). Tumor inhibition was evident in both models studied (intradermal tumors and pulmonary metastasis generation). Everolimus provides potent tumor inhibition in animals inoculated with SCC VII cells. Inhibition of both local and distant spread of disease is evident. Although most immunosuppressives are known to potentiate neoplastic disease, this study supports the use of everolimus immunosuppression in the face of prior malignancy. This data has significant implication for laryngeal transplantation after laryngectomy.

Perioperative Immunomodulation With Flt3 Kinase Ligand or a Whole Tumor Cell Vaccine Is Associated With a Reduction in Lung Metastasis Formation After Laparotomy in Mice

Laparotomy has been associated with temporary postoperative immunosuppression and accelerated tumor growth in experimental models. In a previous murine study, a whole cell vaccine plus the adjuvant monophosphoryl-lipid A was shown to be effective in decreasing the number of lung metastases that develop after laparotomy. This study was conducted to assess the impact of the adjuvant fetal liver tyrosine kinase 3 (Flt3) ligand on perioperative tumor growth when used alone or with a tumor cell vaccine. An intravenous tumor cell injection lung metastases model was used. Sixty female A/J mice were divided into six equal groups designated (1) anesthesia control (AC), (2) AC with Flt3 ligand (ACFlt3), (3) sham laparotomy (OP), (4) OP with Flt3 ligand (OPFlt3), (5) OP with vaccine (OPVac), and (6) OP with Flt3 ligand and vaccine (OPFlt3Vac). Groups 2, 4, and 6 received daily intraperitoneal injections of Flt3 ligand (10 microg/dose with carrier) for 5 days before and 5 days after surgery. Groups 1 and 3 received similar injections of saline on the same schedule. Groups 5 and 6 were vaccinated with irradiated whole Ta3Ha tumor cells intraperitoneally three times before and twice after surgery. Immediately after surgery, all mice were injected with 10(5) Ta3Ha tumor cells via a tail vein. After 14 days, the mice were sacrificed and their lungs and tracheas were excised en bloc. Specimens were stained and counterstained with India ink and Fekete solution, and surface metastases were counted by a blinded observer. Differences between study groups were determined by analysis of variance. The peritumoral inflammatory cell infiltrate of some Flt3 and control specimens was also assessed. Regarding laparotomy, Flt3 ligand (mean, 1.22 metastases), whole cell vaccine (1.12 metastases), and the combination of these two agents (0.1 metastases) were each effective in significantly decreasing the number of surface lung metastases compared with surgery alone (9.88 metastases, P < .05 for all comparisons). There were no differences between the various treatment groups in regards to number of metastases. Only the combination of Flt3 and the vaccine significantly lowered the incidence of tumors (number of mice with > or =1 tumors). Histologic analysis revealed that the Flt3-treated mice demonstrated increased numbers of antigen-presenting cells surrounding the tumors compared with controls. Perioperative treatment with either Flt3 ligand or a whole cell tumor vaccine significantly reduced the number of lung metastases after laparotomy. The combination of the Flt3 ligand and the vaccine also decreased the incidence of metastases and was the most effective treatment. Further studies regarding perioperative immune modulation in the setting of cancer appear warranted.

Suppressive effects of young radish cultivated with sulfur on growth and metastasis of B16-F10 melanoma cells

The oral administration of extracts of young radishes cultivated with sulfur after intravenous tumor cell injection achieved a marked reduction of pulmonary colonization in mice. Treatment of the mice with extracts of young radish cultivated with sulfur did not show any increase in the number of CD8+ or NK T cells in the spleen, indicating no influence on host immunity. Sulforaphane, which could be a candidate for an active compound from young radishes cultivated with sulfur, inhibited cell growth of B16-F10 melanoma cells. In addition, extracts of the young radish cultivated with sulfur-fed group showed enhanced quinine reductase (QR) activities in the liver and lung and a slight increase of glutathione S-transferase (GST) activity in the liver. These results suggested that the administration of extracts of young radishes cultivated with sulfur suppressed pulmonary tumorigenesis, possibly due to increased activity of detoxification enzymes in the liver and lung, and partly due to cell cytotoxicity.

Heteroconjugated antibodies enhance lymphocyte-mediated tumour cell lysis in vitro and in vivo.

Covalent linkage of an antitumour antibody specific for a tumour cell surface antigen to an antilymphocyte antibody specific for the T lymphocyte receptor complex produces a heteroconjugated antibody that can activate and redirect cytotoxic T lymphocytes to lyse tumour cells. The ability of an antilymphocyte-antitumour heteroconjugate (500A2 x 96.5) to direct the lysis of murine melanoma cells by cultured murine lymphocytes was tested in vitro using a 4-h chromium release assay and in vivo with a tumour neutralization assay. In vitro, the addition of heteroconjugated antibody significantly increased tumour lysis by murine C3H/HeN lymphocytes (median specific lysis 82.7 per cent with lymphocytes plus heteroconjugate versus 9.5 per cent for lymphocytes alone, P less than 0.001). In vivo, treatment with heteroconjugated antibody plus lymphocytes significantly reduced the development of pulmonary metastases after intravenous tumour administration (median number of pulmonary metastases 28.5 for combined treatment versus 250 for heteroconjugate or lymphocytes alone, P less than 0.001).

Potent inhibition of local and disseminated tumor growth in immunocompetent mouse models by a bispecific antibody construct specific for Murine CD3

Bispecific single-chain antibody constructs specific for human CD3 have been extensively studied for antitumor activity in human xenograft models using severe combined immunodeficient mice supplemented with human T cells. High efficacy at low effector-to-target ratios, independence of T cell costimuli and a potent activation of previously unstimulated polyclonal T cells were identified as hallmarks of this class of bispecific antibodies. Here we studied a bispecific single-chain antibody construct (referred to as 'bispecific T cell engager', BiTE) in an immunocompetent mouse model. This was possible by the use of a murine CD3-specific BiTE, and a syngeneic melanoma cell line (B16F10) expressing the human Ep-CAM target. The murine CD3-specific BiTE, called 2C11x4-7 prevented in a dose-dependent fashion the outgrowth of subcutaneously growing B16/Ep-CAM tumors with daily i.v. injections of 5 or 50 microg BiTE which was most effective. Treatment with 2C11x4-7 was effective even when it was started 10 days after tumor cell inoculation but delayed treatments showed a reduction in the number of cured animals. 2C11x4-7 was also highly active in a lung tumor colony model. When treatment was started on the day of intravenous tumor cell injection, seven out of eight animals stayed free of lung tumors, and three out of eight animals when treatment was started on day 5. Our study shows that BiTEs also have a high antitumor activity in immunocompetent mice and that there is no obvious need for costimulation of T cells by secondary agents.

Radioiodinated phenylalanine derivatives to image pancreatic cancer: a comparative study with [ 18F]fluoro-2-deoxy- d-glucose in human pancreatic carcinoma xenografts and in inflammation models

This work validated an in vivo model of human pancreatic cancer for preclinical studies and evaluated p-amino-3-[ 123I]iodo- l-phenylalanine (AIPA) and p-[ 123I]iodo- l-phenylalanine (IPA) as potential imaging agents for pancreatic cancer. The primary human pancreatic adenocarcinoma PaCa44 and PanC1 cells (1.5–2.5×10 6) were inoculated either subcutaneously into the flank or orthotopically into the pancreas of severe combined immunodeficient (SCID) mice. Tumor formation was recorded by palpation and monitored by magnetic resonance imaging (MRI). After intravenous injection, tumor affinity and organ distribution of AIPA and IPA were compared with those of [ 18F]fluoro-2-deoxy- d-glucose (FDG) in tumor-bearing SCID mice and in concanavalin A (ConA)-induced inflammation models. All SCID mice developed a pancreatic tumor 2–4 weeks after cell implantation. All subcutaneously transplanted tumors were detected by MRI and confirmed histologically, whereas 90% and 68% of the histopathologically confirmed orthotopic PaCa44 and PanC1 tumors were accurately demonstrated by MRI. Tumor formation and spread after orthotopic implantation showed invasion into adjacent organs and metastases in different sites of the abdomen. In contrast, no organ invasion or metastases were demonstrated by subcutaneous implantation. In vivo, AIPA and IPA displayed high affinity for pancreatic tumors. Radioactivity uptake into a tumor at 60 and 240 min amounted to 7.2±2.1% and 10.7±2.5% I.D./g for AIPA and 13.3±3.5% and 15.2±3.8% I.D./g for IPA in heterotopic tumors as compared with 11.8±3.2% and 15.2±2.4% I.D./g for AIPA and 16.7±3.5% and 22.5±4.3% I.D./g for IPA in orthotopically implanted tumors. In comparison, the FDG uptake was 10.8±2.9% and 2.5±0.6% I.D./g into heterotopic tumors and 12.5±3.8% and 3.5±1.2% I.D./g into the orthotopic ones at 60 and 240 min postinjection. The FDG uptake markedly increased (>400%) in the area of inflammation, whereas accumulation of AIPA and IPA in inflammation remained moderate and comparable with that determined in muscle. In summary, the orthotopic implantation model, more than the heterotopic one, reflects more closely the clinical course of the disease, thus representing the appropriate in vivo model for preclinical studies. The specific and high-level targeting of AIPA and IPA to human pancreatic tumor xenografts, with marked tumor-to-background ratios, indicate that AIPA and IPA are interesting candidates as radiotracers for noninvasive imaging of pancreatic cancer. IPA has the advantage of relatively low renal uptake and thus presents as the most promising candidate.

Resection of an intravenous leiomyoma with intracardiac extension with use of endovascular techniques

Intravenous leiomyoma with intracardiac extension is a rare entity that necessitates surgical excision to alleviate symptoms and prevent life-threatening complications. These procedures are generally performed under cardiopulmonary bypass, and review of the literature reveals an evolution in management of this disease from 2-stage to single-stage procedures. We report the case of a 45-year-old woman with an intravenous leiomyoma with intracardiac extension after presenting with syncopal symptoms. The intravenous tumor and its supradiaphragmatic extension were ultimately resected via laparotomy without the need for cardiopulmonary bypass. Distal control was achieved by passing an occluding balloon catheter above the tumor through a venotomy with fluoroscopic guidance and echocardiography, thus enabling protected tumor extraction through the intra-abdominal inferior vena cava. In selected patients, we believe use of endovascular techniques combined with proper preoperative imaging can safely permit single-stage resection of these tumors via laparotomy without cardiopulmonary bypass.

CpG-Oligodeoxynucleotides activate tyrosinase-related protein 2-specific T lymphocytes but do not lead to a protective tumor-specific memory response.

Peritumoral CpG-oligodeoxynucleotide (ODN) treatment has been successful in tumor mouse models expressing strong antigens to induce activation of tumor-specific CD8+ T lymphocytes which contribute to the control of tumor growth. To get near to clinical reality, the tumor-specific CD8+ response was investigated in mice bearing the weakly immunogenic B16 melanoma tumor and using the melanocyte differentiation tyrosinase-related protein 2 (TRP-2) as a tracking antigen. The expansion and activation of TRP-2-specific T lymphocytes by CpG-ODNs was analyzed by tetramer staining and IFN-gamma production assays, while the activity of these cells in both memory and primary response was evaluated in vivo. After CpG-ODN treatment, the number of TRP-2 tetramer-stained CD8+ T lymphocytes was not significantly modified, but these cells produced higher levels of interferon gamma (IFN-gamma) in response to the antigen than those from untreated mice. Mice possessing these activated T lymphocytes, when evaluated for their antitumor memory response, showed marginal protection against intravenous (i.v.) and subcutaneous (s.c.) tumor rechallenge. These cells were not crucial for the control of primary tumor growth since strong reduction of subcutaneous tumor was observed after CpG-ODN treatment in both CD8+ T cell depleted or nondepleted mice. On the contrary, NK cell depletion markedly reduced CpG-ODN-induced tumor growth inhibition. Altogether, these data indicate the CpG treatment activates tumor-reactive effector CD8+ T lymphocytes, but, paralleling recent clinical observations, our model indicates that the mere activation of antitumor T cells is insufficient to result in a clinical response.

Synergistic anti-tumor effect of glycosylphosphatidylinositol-anchored IL-2 and IL-12.

Preclinical and clinical studies have demonstrated that interleukin 2 (IL-2), interleukin 12 (IL-12), and some other cytokines, play important roles in activating host immune responses against tumor growth. However, severe side effects caused by systemic high-dose administration of these cytokines limit their clinical application. In our previous study, local high doses of IL-2 were achieved by a GPI-anchoring technology; therefore, it will be interesting to know if this technology works for other cytokines. A fusion gene containing murine IL-12 and the glycosylphosphatidylinositol (GPI) anchor signal sequence was generated and transfected into the murine melanoma tumor cell line B16F0 either alone or together with a vector encoding GPI-anchored IL-2. The GPI-anchored cytokine expression of the selected stable clones was assayed in vitro by ELISA and their anti-tumor effects were analyzed in vivo by tumor lymphocyte infiltration and tumor growth studies. GPI-anchored IL-12 was successfully expressed on the cell surface as indicated by FACS analysis and IL-12 ELISA assay. The GPI-anchored IL-12 enhanced lymphocyte infiltration and significantly inhibited tumor growth. More importantly, when GPI-anchored IL-12 and GPI-anchored IL-2 were co-delivered, a synergistic anti-tumor effect was observed in both subcutaneous and intravenous tumor models. GPI anchorage of cytokines represents a new approach to locally deliver high doses of cytokines without the severe adverse effects normally accompanied with systematic high-dose administration of these cytokines.

Treatment of severe recalcitrant plaque psoriasis with single-dose intravenous tumour necrosis factor-alpha antibody (infliximab).

Infliximab is a chimeric anti-tumour necrosis factor-alpha antibody that has been demonstrated to have marked efficacy in the treatment of psoriasis. Seven patients with chronic plaque psoriasis were treated with single-dose intravenous infliximab (5 mg/kg), and the Psoriasis Area and Severity Index (PASI) and Dermatology Life Questionnaire Index (DLQI) were used as a measure of treatment efficacy. There was an average improvement in PASI scores of 69% at 2 weeks post infusion. There was an improvement in DLQI of 61%. Four of the seven patients were also seen at 10 weeks post infusion and the improvement in PASI and DLQI was sustained. All patients tolerated the initial infusion well without adverse events. The results indicate that single-dose infliximab is an effective and efficacious therapy for recalcitrant psoriasis and has a prolonged therapeutic effect.

Cytoplasmic and/or nuclear staining of beta-catenin is associated with lung metastasis.

Beta-catenin is involved in cell motility in the extracellular matrix, and is expressed in normal and neoplastic mesenchymal cells. In order to clarify whether beta-catenin expression in the cytoplasm and/or nucleus is associated with a propensity for pulmonary metastasis in osteosarcoma, the LM8 murine osteosarcoma cell line with a high metastatic potential to the lung was compared with original Dunn cells in terms of the beta-catenin expression level. Both osteosarcoma cell lines lost membrane localization of beta-catenin. However, beta-catenin gene had no mutation in exon 3 by direct sequence analysis. A large number of LM8 cells showed diffuse cytoplasmic and/or nuclear staining of beta-catenin (30.8 per high power field (HPF)), while a much smaller number of Dunn cells showed expression of beta-catenin (7.7 per HPF). Cells with positive staining of beta-catenin were frequently seen at the invasive front and in intravenous tumor deposits within the metastatic lesions to the lung. Thus, LM8 cells express a larger amount of the beta-catenin protein than Dunn cells, as judged by immunoblot analysis. In five resected cases of pulmonary metastasis, translocation of beta-catenin to the cytoplasm and/or nucleus of osteosarcoma cells was detected, although seven primary osteosarcomas cells that did not metastasize for more than five years did not show beta-catenin expression. These data indicate that the cytoplasmic and/or nuclear staining of beta-catenin is a biological marker of metastatic potential of osteosarcoma to the lung.

Persistent, antigen-specific, therapeutic antitumor immunity by dendritic cells genetically modified with an adenoviral vector to express a model tumor antigen.

Dendritic cells (DC) are potent antigen-presenting cells that play a critical role in the initiation of cellular immune responses. Using a BALB/c syngeneic colon carcinoma cell line expressing a model tumor antigen beta-galactosidase (betagal), we previously reported (Song et al, J Exp Med 1997; 186: 1247-1256) that immunization of mice with a single injection of DCs genetically modified with an adenovirus vector expressing betagal confers potent protection against a lethal intravenous tumor challenge, as well as suppression of pre-established lung tumors, resulting in a significant survival advantage. In the present study, we have addressed the question: how long does the memory of tumor antigen- specific immunity persists after DC priming in vivo using this genetically modified DC-based cancer vaccination strategy? To accomplish this, two groups of mice were evaluated: (1) mice surviving >400 days following protection from an initial intravenous tumor challenge after immunization with DC genetically modified to express betagal; and (2) mice surviving >300 days that had previously demonstrated regression of pre-established lung tumors after treatment with DC immunization. By analyzing the antigen-specific cytotoxic T lymphocyte response and challenging these long-term survival mice with a second subcutaneous tumor administration, the data demonstrate that a single administration of DC genetically modified to express a model antigen induces long-lasting, antigen-specific antitumor immunity in both naive and tumor-bearing hosts, observations that have important implications in the development of genetically modified DC-based antitumor vaccination strategies. Gene Therapy (2000) 7, 2080-2086.

A case report of intravenous leiomyomatosis extending into the heart

The patient was a 47-year-old woman who underwent total hysterectomy for uterine leiomyoma in 1994. Two years later, intracaval and intravenous tumors were found by ultrasonic cardiography, magnetic resonance imaging, enhanced chest computed tomography, and venography. The patient underwent total removal of these tumors. Pathological findings indicated that these tumors were leiomyomas. After comparing the present findings with those of similar cases in the literature, we concluded that our patient had intravenous leiomyomatosis extending into the heart.

Effects of circulating tumor necrosis factor on the neuronal activity and expression of the genes encoding the tumor necrosis factor receptors (p55 and p75) in the rat brain: a view from the blood–brain barrier

Tumor necrosis factor is a potent activator of myeloid cells, which acts via two cell-surface receptors, the p55 and p75 tumor necrosis factor receptors. The present study describes the cellular distribution of both receptor messenger RNAs across the rat brain under basal conditions and in response to systemic injection with the bacterial endotoxin lipopolysaccharide and recombinant rat tumor necrosis factor-α. Time-related induction of the messenger RNA encoding c- fos, cyclo-oxygenase-2 enzyme and the inhibitory factor kappa B alpha was assayed as an index of activated neurons and cells of the microvasculature by intravenous tumor necrosis factor-α challenge. The effect of the proinflammatory cytokine on the hypothalamic–pituitary–adrenal axis was determined by measuring the transcriptional activity of corticotropin-releasing factor and plasma corticosterone levels. Constitutive expression of p55 messenger RNA was detected in the circumventricular organs, choroid plexus, leptomeninges, the ependymal lining cells of the ventricular walls and along the blood vessels, whereas p75 transcript was barely detectable in the brain under basal conditions. Immunogenic insults caused up-regulation of both tumor necrosis factor receptors in barrier-associated structures, as well as over the blood vessels, an event that was associated with a robust activation of the microvasculature. Indeed, intravenous tumor necrosis factor-α provoked a rapid and transient transcription of inhibitory factor kappa B alpha and cyclo-oxygenase-2 within cells of the blood–brain barrier, and a dual-labeling technique provided the anatomical evidence that the endothelium of the brain capillaries expressed inhibitory factor kappa B alpha. Circulating tumor necrosis factor-α also rapidly stimulated c- fos expression in nuclei involved in the autonomic control, including the bed nucleus of the stria terminalis, the paraventricular nucleus of the hypothalamus, the central nucleus of the amygdala, the nucleus of the solitary tract and the ventrolateral medulla. A delayed c- fos mRNA induction was detected in the circumventricular organs, organum vascularis of the lamina terminalis, the subfornical organ, the median eminence and the area postrema. The paraventricular nucleus of the hypothalamus exhibited expression of corticotropin-releasing factor primary transcript that was associated with a sharp increase in the plasma corticosterone levels 1 h after intravenous tumor necrosis factor-α administration. Taken together, these data provide the evidence that p55 is the most abundant tumor necrosis factor receptor in the central nervous system and is expressed in barrier-associated structures. Circulating tumor necrosis factor has the ability to directly activate the endothelium of the brain's large blood vessels and small capillaries, which may produce soluble molecules (such as prostaglandins) to vehicle the signal through parenchymal elements. The pattern of c- fos-inducible nuclei suggests complex neuronal circuits solicited by the cytokine to activate neuroendocrine corticotropin-releasing factor and the corticotroph axis, a key physiological response for the appropriate control of the systemic inflammatory response.

Immunogenicity and antitumor activity of a liposomal MUC1 peptide-based vaccine

A human MUC1-transfected mouse mammary adenocarcinoma cell line (GZHI) was used to develop both subcutaneous and intravenous tumor models. A vaccine formulation comprised of a 24 mer (human MUC1) synthetic peptide encapsulated with monophosphoryl lipid A adjuvant (MPLA) in multilamellar liposomes was tested for immunogenicity and anti-tumor activity. A low dose of the human MUC1 peptide (5 microg) administered in liposomes provided excellent protection of mice in both tumor challenge models. The protective antitumor activity mediated by the liposome formulation correlated with anti-MUC1-specific T-cell proliferation, gamma-interferon (IFN-gamma) production and IgG2a anti-MUC1 antibodies, suggesting a type 1 (T1) T-cell response. In contrast, lack of protection in mice immunized with negative control vaccines correlated with IgG1 anti-MUCI antibody formation, low or no anti-MUC1 IgG2a and low antigen-specific T-cell proliferation, consistent with a type 2 (T2) T-cell response to the tumor.

Morphological study of vascular dissemination in a metastatic hepatocellular carcinoma model in the monkey.

In this report we describe a metastatic monkey hepatocellular carcinoma (HCC) model in which intravascular metastatic development is clearly evident. The tumor-bearing livers contained intravenous tumor thrombi at different stages of progression within the small branches of the portal vein. These ranged from mural tumor thrombi lined with CD31-positive endothelial cells to tumor thrombi that had completely occluded the vascular lumen. Intravenous tumor expansion was frequently accompanied by the appearance of CD31-positive microvessels within the tumor thrombi and fibrous perivascular thickening, giving rise to isolated tumor nodules within the portal areas. Intravascular expansion of disseminating HCC was also evident within small branches of the pulmonary arteries in the lungs. These findings indicate that metastases of HCC can become established while still at an intravascular stage, suggesting that the direct interaction between tumor cells and parenchymal cells predicted from experimental rodent metastasis models is not a prerequisite for the metastatic development of these tumors.

Morphological study of vascular dissemination in a metastatic hepatocellular carcinoma model in the monkey

In this report we describe a metastatic monkey hepatocellular carcinoma (HCC) model in which intravascular metastatic development is clearly evident. The tumor-bearing livers contained intravenous tumor thrombi at different stages of progression within the small branches of the portal vein. These ranged from mural tumor thrombi lined with CD31-positive endothelial cells to tumor thrombi that had completely occluded the vascular lumen. Intravenous tumor expansion was frequently accompanied by the appearance of CD31-positive microvessels within the tumor thrombi and fibrous perivascular thickening, giving rise to isolated tumor nodules within the portal areas. Intravascular expansion of disseminating HCC was also evident within small branches of the pulmonary arteries in the lungs. These findings indicate that metastases of HCC can become established while still at an intravascular stage, suggesting that the direct interaction between tumor cells and parenchymal cells predicted from experimental rodent metastasis models is not a prerequisite for the metastatic development of these tumors. (Hepatology 1997 Nov;26(5):1209-15)

The anti-inflammatory approach to septic shock

Our clinical experience with anti-inflammatory agents in patients with sepsis has been a disappointing one thus far. To better define the role of inflammation and the applicability of immunomodulators in sepsis, we have administered either anti-inflammatory (leukocyte adhesion complex directed monoclonal antibodies, CD11/18 MAb) or pro-inflammatory (recombinant granulocyte colony stimulating factor, G-CSF) agents in animals challenged with infectious or noninfectious inflammatory stimuli at intra- or extravascular sites. Inhibition of inflammation with CD11/18 MAb, reduced lung injury and improved survival with intravenous (TV) tumor necrosis factor (TNF) in canines. However, CD11/18 MAb with intrabronchial (IB) or intraperitoneal (IP) E. coli challenge, although improving lung injury with pneumonia, worsened host defense, hemodynamics and survival. In canines with IP or IB E. coli, or IV endotoxin, prophylactic G-CSF improved host defense, hemodynamics and survival. However, G-CSF with IB E. coli in the canine increased lung dysfunction and with a higher bacterial dose in the rat worsened both lung injury and survival. In additional studies in rats alone, the effects of prophylactic G-CSF on survival were fundamentally different, depending upon the site and the lethality of E. coli challenge. In a final study, canines were challenged with IP E. coli and then treated with G-CSF therapeutically. Despite using a range of doses, G-CSF did not improve any parameter of outcome in these studies and in very high doses appeared harmful. In our animal models, both pro- and anti-inflammatory agents had widely divergent effects on organ injury and survival. The disparate roles of inflammation in host defense and tissue injury may in part explain these results. Altering the inflammatory response during sepsis is more complicated than we originally expected. For pro- and anti-inflammatory agents to be maximally effective in clinical trials of sepsis, our animal data suggest that the influence of variables related to both the therapy (e.g. dose and timing) and the precipitating infection (e.g. severity, site and type) need to be clarified.

The effect of pentoxifylline on spontaneous and experimental metastasis of the mouse Neuro2a neuroblastoma.

Pentoxifylline (PTX) has been reported to have both direct and indirect anti-tumor effects in experimental tumor models. We studied the effect of PTX on (1) the proliferation of Neuro2a mouse neuroblastoma cells in vitro and in vivo, (2) spontaneous and experimental metastasis, (3) tumor cell membrane fluidity and (4) adhesion to a fibronectin-coated surface. PTX significantly reduced the proliferation of Neuro2a cells in vitro as determined by DNA measurement (P < 0.01) and total cell count (P < 0.02). In vivo, PTX reduced the growth of subcutaneously transplanted primary tumors in syngeneic A/J mice (P < 0.01; n = 15). All seven animals (100%) receiving intravenous tumor cells developed extensive liver metastasis. In contrast, only 1/11 (9%) of animals pre-treated with oral PTX and injected with PTX-treated cells developed liver metastases. Of five mice receiving PTX-treated cells without oral pretreatment of PTX, two out of five (40%) developed liver metastases. There was a slight, but not significant (P = 0.08) increase in both experimental and spontaneous lung metastases formation in PTX-treated animals. However, tumor nodule formation on the lung surface was inefficient. PTX also increased membrane fluidity of the Neuro2a cells and significantly decreased tumor cell adhesion to fibronectin-coated microtiter wells (P < 0.01). We conclude that PTX has a cytostatic effect on the Neuro2a mouse neuroblastoma and exerts an anti-tumor effect on liver metastases following intravenous administration of neuroblastoma cells. Whether these results are directly related to the changes in membrane properties caused by pentoxifylline remains to be established.

Histologic features and clinical significance of venous invasion in colorectal carcinoma with hepatic metastasis.

In colorectal carcinoma, venous invasion has been related to patient survival. Liver metastasis develops more frequently when venous invasion is present. However, the histologic features and clinical significance of venous invasion are not well understood. A histologic study of venous invasion in colorectal carcinoma was performed on 19 patients with synchronous hepatic metastasis (Group A), 16 patients with metacaronous hepatic metastasis (Group B), and 26 patients with Dukes Stage C tumors who survived for 5 years without recurrence (Group C). The histologic features of venous invasion were classified into three types: tumor cells that were distant from the vein walls were categorized as floating type, those filling the lumen of a vein as filling type, and those surrounded by a vein obliterated with inflammatory reaction as occlusive type. Venous invasion was present in 89.5% of Group A patients and 75% of Group B patients, which was significantly higher than the 15.4% observed in Group C patients (P < 0.001). A slight to extensive degree of venous invasion was found in Groups A and B, but no extensive venous invasion was found in Group C. All patients in Groups A and B (except one patient) had floating, filling, or a combination of floating and filling types of venous invasion, whereas all patients in Group C had the occlusive type of venous invasion. A majority of the patients in all three groups showed invasion of extramural veins. There is a close relationship between venous invasion and the development of liver metastasis in patients with colorectal carcinoma. Patients with no sign of metastasis had a lower incidence and lower extent of venous invasion, and inflammatory damage to the vein walls around the intravenous tumor appeared to reduce the likelihood of distant metastasis.