Reduction Of Pulmonary Metastases Research Articles

ADRB3 induces mobilization and inhibits differentiation of both breast cancer cells and myeloid-derived suppressor cells

Metastatic tumors are mainly composed of neoplastic cells escaping from the primary tumor and inflammatory cells egressing from bone marrow. Cancer cell and inflammatory cell are remained in the state of immaturity during migration to distant organs. Here, we show that ADRB3 is crucial in cell mobilization and differentiation. Immunohistochemistry revealed ADRB3 expression is significantly more frequent in breast cancer tissues than in adjacent noncancerous tissues (92.1% vs. 31.5%). Expression of ADRB3 correlated with malignant degree, TNM stage and poor prognosis. Moreover, ADRB3 expression was markedly high in activated disseminated tumor cells, myeloid-derived suppressor cells (MDSCs), lymphocytes and neutrophil extracellular traps of patients. Importantly, ADRB3 promoted the expansion of MDSC through stimulation of bone marrow mobilization and inhibiting of the differentiation of immature myeloid cells. Furthermore, ADRB3 promoted MCF-7 cells proliferation and inhibited transdifferentiation into adipocyte-like cell by activating mTOR pathway. Ultimately, the MDSC-deficient phenotype of ADRB3 -/- PyMT mice was associated with impairment of mammary tumorigenesis and reduction in pulmonary metastasis. Collectively, ADRB3 promotes metastasis by inducing mobilization and inhibiting differentiation of both breast cancer cells and MDSCs.

Abstract B73: Pleiotrophin drives a pro-malignant macrophage phenotype in preclinical models of breast cancer

Abstract Tumor-associated macrophages promote progression to malignancy, metastasis, and resistance to chemotherapy in breast and pancreatic cancer. Furthermore, macrophage recruitment in tumors correlates with a worse prognosis in breast cancer patients. The phenotype of tumor associated macrophages is influenced by many factors, including the cytokine milieu within the tumor. We have identified a population of macrophages in genetic models of breast cancer that express Vascular Endothelial Growth Factor Receptor 2 (Vegfr2). Using flow cytometry and immunohistochemical analyses, we found that this population is enriched for markers associated with macrophages that promote angiogenesis, immune suppression, and metastasis. In vitro, we identified the heparin-binding peptide, pleiotrophin (PTN), as a candidate cytokine that induces Vegfr2 and anti-inflammatory cytokine expression by macrophages. Additionally, we found that PTN-stimulated macrophages can greatly increase cancer cell migration in vitro. In the MMTV-PyMT transgenic murine model of breast cancer, we observed that expression of PTN correlates with levels of Vegfr2+ macrophages and progression to malignancy. Crizotinib, an inhibitor of the pleiotrophin receptor, Anaplastic Lymphoma Kinase, reduced anti-inflammatory and Vegfr2+ macrophages in vivo. This decrease was concomitant with a significant reduction in pulmonary metastasis. This finding was corroborated by the use of 3B10, a neutralizing pleiotrophin monoclonal antibody. The potential impact of this work includes identifying a novel biomarker of promalignant macrophages, a therapeutic strategy to target them, and developing a deeper understanding of the function of macrophages in metastasis. Citation Format: Noah Sorrelle, Kristi D. Lynn, Adrian TA Dominguez, Eric Berens, Jason E. Toombs, Anton Wellstein, Rolf A. Brekken. Pleiotrophin drives a pro-malignant macrophage phenotype in preclinical models of breast cancer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr B73.

Loading Lovastatin into Camptothecin-Floxuridine Conjugate Nanocapsules for Enhancing Anti-metastatic Efficacy of Cocktail Chemotherapy on Triple-negative Breast Cancer.

Triple-negative breast cancer (TNBC) is a malignant and refractory disease with high morbidity and mortality. The TNBC shows no response to hormonal therapy nor targeted therapy due to the lack of known targetable biomarkers. Furthermore, the TNBC also exhibits a high degree of heterogeneity that leads to cancer evolution, drug resistance, metastatic progression, and recurrence, arising from the tumor-initiating properties of cancer stem cells (CSCs). Thus, the development of radical therapeutic regimens with high efficacy and limited side effects is crucial. In this study, we designed an innovative ternary cocktail chemotherapy by using Lovastatin (L)-loaded Janus camptothecin-floxuridine conjugate (CF) nanocapsules (NCs) with ultrahigh drug loading capacity. The obtained LCF NCs were shown to be able to suppress growth of TNBC, including inhibition of growth and metastasis of CSCs, both in vitro and in tumor-bearing mice. Moreover, in animal experiments, the LCF NCs showed sustained and synchronous drug release (half-life > 300 min), 85.2% reduction in pulmonary metastases, and no cancer recurrence during one-month observation post-treatment. Thus, this innovative LCF NC design provides a simple and synergistic strategy for the development of simultaneous triple chemotherapy and could be an efficacious, safe, and amenable choice with higher therapeutic relevance and fewer toxic complications than conventional multidrug delivery systems for TNBC treatment in the future.

Genome-wide in vivo screen identifies novel host regulators of metastatic colonization.

Metastasis is the leading cause of death for cancer patients. This multi-stage process requires tumour cells to survive in the circulation, extravasate at distant sites, then proliferate; it involves contributions from both the tumour cell and tumour microenvironment ('host', which includes stromal cells and the immune system). Studies suggest the early steps of the metastatic process are relatively efficient, with the post-extravasation regulation of tumour growth ('colonization') being critical in determining metastatic outcome. Here we show the results of screening 810 mutant mouse lines using an in vivo assay to identify microenvironmental regulators of metastatic colonization. We identify 23 genes that, when disrupted in mouse, modify the ability of tumour cells to establish metastatic foci, with 19 of these genes not previously demonstrated to play a role in host control of metastasis. The largest reduction in pulmonary metastasis was observed in sphingosine-1-phosphate (S1P) transporter spinster homologue 2 (Spns2)-deficient mice. We demonstrate a novel outcome of S1P-mediated regulation of lymphocyte trafficking, whereby deletion of Spns2, either globally or in a lymphatic endothelial-specific manner, creates a circulating lymphopenia and a higher percentage of effector T cells and natural killer (NK) cells present in the lung. This allows for potent tumour cell killing, and an overall decreased metastatic burden.

Pulmonary metastases in differentiated thyroid cancer: efficacy of radioiodine therapy and prognostic factors.

Data from a large cohort of patients with pulmonary metastases from differentiated thyroid cancer (DTC) were retrospectively analyzed. To assess the effect of radioiodine therapy and investigate the prognostic factors of survival for patients with pulmonary metastasis secondary to DTC. A total of 372 patients with pulmonary metastasis from DTC treated with (131)I entered the study. According to the results of (131)I whole-body scan (WBS), pulmonary metastases were classified as (131)I-avid and non-(131)I-avid. For patients with (131)I-avid lung metastases, treatment response was measured by three parameters: serum thyroglobulin (Tg) levels, chest computed tomography (CT) and post-therapeutic (131)I-WBS. Overall survival was calculated by the Kaplan-Meier method. Factors predictive of the outcome were determined by multivariate analyses. Among patients demonstrating (131)I-avid pulmonary metastases (256/372, 68.8%), 156 cases (156/256, 60.9%) showed a significant decrease in serum Tg levels after (131)I therapy and 138 cases (138/229, 60.3%) showed a reduction in pulmonary metastases on follow-up CT. A complete cure, however, was only achieved in 62 cases (62/256, 24.2%). Multivariate analysis showed that only age, the presence of multiple distant metastases and pulmonary metastatic node size were significant independent variables between the groups of (131)I-avid and non-(131)I-avid. This study indicated that, most (131)I-avid pulmonary metastases from DTC can obtain partial or complete remission after (131)I therapy. Younger patients (<40 years old) with only pulmonary metastases and small ('fine miliaric' or micronodular) metastases appear to have relative favorite outcomes. Patients who do not respond to (131)I treatment have a worse prognosis.

Role of chitinase 3-like-1 and semaphorin 7a in pulmonary melanoma metastasis.

The prototypic chitinase-like protein Chi3l1 is induced in cancers and portends a poor prognosis, but whether it contributes to cancer progression is unknown. To address this gap in knowledge, we investigated the production of Chi3l1 in melanoma lung metastases. We found that Chi3l1 was induced during pulmonary melanoma metastasis and that this induction was regulated by the semaphorin Sema7a, interacting in stimulatory or inhibitory ways with its β1 integrin or Plexin C1 receptors, respectively. In mouse strains with genetic deletions of Chi3l1 or Sema7a, there was a significant reduction in pulmonary metastasis. Notably, antiserum raised against Chi3l1 or Sema7a phenocopied the reduction produced by genetic deletions. Melanoma lung metastasis was also decreased in the absence of IL13Rα2, a recently identified receptor for Chi3l1, consistent with a key role for Chi3l1 in melanoma spread. We confirmed roles for Sema7a and Chi3l1 in pulmonary metastasis of EMT6 breast cancer cells. Taken together, our studies establish a novel pathway through which Sem7a and its receptors regulate Chi3l1, revealing a host axis involving IL13Rα2 that plays a critical role in generating a pulmonary microenvironment that is critical to license metastasis.

S-adenosylmethionine blocks osteosarcoma cells proliferation and invasion in vitro and tumor metastasis in vivo: therapeutic and diagnostic clinical applications.

Osteosarcoma (OS) is an aggressive and highly metastatic form of primary bone cancer affecting young children and adults. Previous studies have shown that hypomethylation of critical genes is driving metastasis. Here, we examine whether hypermethylation treatment can block OS growth and pulmonary metastasis. Human OS cells LM-7 and MG-63 were treated with the ubiquitous methyl donor S-adenosylmethionine (SAM) or its inactive analog S-adenosylhomocystine (SAH) as control. Treatment with SAM resulted in a dose-dependent inhibition of tumor cell proliferation, invasion, cell migration, and cell cycle characteristics. Inoculation of cells treated with 150 μmol/L SAM for 6 days into tibia or via intravenous route into Fox Chase severe combined immune deficient (SCID) mice resulted in the development of significantly smaller skeletal lesions and a marked reduction in pulmonary metastasis as compared to control groups. Epigenome wide association studies (EWAS) showed differential methylation of several genes involved in OS progression and prominent signaling pathways implicated in bone formation, wound healing, and tumor progression in SAM-treated LM-7 cells. Real-time polymerase chain reaction (qPCR) analysis confirmed that SAM treatment blocked the expression of several prometastatic genes and additional genes identified by EWAS analysis. Immunohistochemical analysis of normal human bone and tissue array from OS patients showed significantly high levels of expression of one of the identified gene platelet-derived growth factor alpha (PDGFA). These studies provide a possible mechanism for the role of DNA demethylation in the development and metastasis of OS to provide a rationale for the use of hypermethylation therapy for OS patients and identify new targets for monitoring OS development and progression.

Downregulation of microRNA-100 enhances the ICMT-Rac1 signaling and promotes metastasis of hepatocellular carcinoma cells.

Metastasis is responsible for rapid recurrence of hepatocellular carcinoma (HCC) and poor survival of HCC patients. Here we showed that miR-100 downregulation in HCC tissues was significantly associated with venous invasion, advanced TNM stage, tumor nodule without complete capsule, poorer cell differentiation, and shorter recurrence-free survival. Both gain- and loss-of-function studies showed that miR-100 dramatically suppressed the ability of HCC cells to migrate and to invade through Matrigel in vitro. Analyses using mouse orthotopic xenograft model further revealed that xenografts of miR-100-stable-expressing HCC cells displayed a significant reduction in pulmonary metastasis, compared with control group. Subsequent investigations revealed that miR-100 directly inhibited the expression of isoprenylcysteine carboxyl methyltransferase (ICMT) and ras-related C3 botulinum toxin substrate 1 (Rac1) by binding to their 3'-UTRs, and in turn suppressed lamellipodia formation and matrix metallopeptidase 2 (MMP2) activation. Furthermore, knockdown of ICMT and Rac1 phenocopied the anti-metastasis effect of miR-100, whereas overexpression of the constitutively active Rac1 (Q61L) antagonized the function of miR-100. Taken together, miR-100 represses metastasis of HCC cells by abrogating the ICMT-Rac1 signaling. Downregulation of miR-100 contributes to HCC metastasis and the restoration of miR-100 is a potential strategy for cancer therapy.

Abstract 2072: Chitinase-3-like-1 protein expression associated with pulmonary inflammation accelerates metastasis to the lung

Abstract Disseminated metastasis accounts for majority of breast cancer deaths. Recently, elevated serum levels of a glycoprotein known as chitinase-3-like-1 protein (CHI3L1) has been correlated with poor prognosis and shorter survival of patients with metastatic breast cancer. We found that there are elevated levels of CHI3L1 in plasma of mammary tumor-bearing mice. However, the biological and physiological functions of CHI3L1 are still unclear. We previously found that CHI3L1 has an inhibitory role on the expression of interferon-gamma, and in up-regulation of pro-inflammatory mediators such MCP-1, IL-8 and MMP-9 all of which contribute towards tumor growth and metastasis. In determining the cause of high levels of CHI3L1 in plasma, we found that in addition to tumor cells, splenic macrophages and more interestingly pulmonary macrophages from mammary tumor bearers secrete high levels of CHI3L1. Additionally, allergic mice also expressed higher levels of CHI3L1 in circulation and lung tissue. More specifically, CD11b+Ly6C+ cells from the lungs of allergic mice produced higher amounts of CHI3L1 compared to control mice. We have previously established that pulmonary myeloid cells through their production of CHI3L1 set up the proper microenvironment for growth of incoming mammary tumor cells. Thus, we hyphothesize that CHI3L1 levels in the lungs of mice with allergic pulmonary inflammation could accelerate metatstasis. To understand the role of CHI3L1 in accelerating pulmonary metastasis, pulmonary inflammation was induced by sensitization with ragweed allergen. Allergic mice implanted with either 4T1 or 67NR mammary tumors had a 5-fold increase in tumor volume, and formation of metastatic foci in their lungs compared to control mammary tumor bearers. Further, allergic mice showed accelerated tumor growth and shorter survival. In contrast, CHI3L1 null mice showed decreased tumor volume and metastasis, and increased survival compared to control mice. In vivo administration of chitin (β-(1-4)-poly-N-acetyl D-glucosamine) microparticles, the ligand for CHI3L1, to control and allergic mammary tumor bearers resulted in a significant reduction in pulmonary metastasis and tumor growth. These studies suggest that CHI3L1 plays a role in tumor progression and that chitin microparticles can inhibit the pleiotropic effects of CHI3L1 giving support to the idea that CHI3L1 is a useful target for treatment of breast cancer. Citation Format: Stephania Libreros, Ramon Garcia-Areas, Vijaya Iragavarapu-Charyulu. Chitinase-3-like-1 protein expression associated with pulmonary inflammation accelerates metastasis to the lung. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2072. doi:10.1158/1538-7445.AM2014-2072

Abstract A083: Neutrophils promote metastasis of invasive lobular carcinoma

Abstract The multistep process of metastasis is highly dependent on the intrinsic mutations that accumulate in cancer cells. However, recent experimental evidence has shown that these mutations are not sufficient to facilitate metastatic disease. Cues from the tumor microenvironment are also required. In order to understand how systemic changes might affect metastasis formation, we profiled the cellular and molecular alterations in various organs of K14cre;EcdF/F;p53F/F mammary tumor-bearing mice – a model of invasive lobular breast cancer. Among all immune cells, increased neutrophil accumulation was the most pronounced. To test the functional importance of neutrophils in the metastatic process, we utilized our recently described model of spontaneous metastasis. This model is based on the transplantation of K14cre;EcdF/F;p53F/F tumor pieces into wild-type recipient mice, and subsequent surgical removal of the primary tumor, permitting us to investigate neutrophil function in both the neoadjuvant and adjuvant settings. Interestingly, mice treated with neutrophil-depleting antibodies in the neoadjuvant setting displayed a profound reduction in pulmonary metastasis, whereas metastases in the adjuvant group were equivalent to controls. These data indicate that neutrophils play a prominent role during the very early stages of the metastatic cascade. Our preliminary data suggest that these tumor-educated neutrophils can suppress the activation of T cells, as one mechanism by which they may promote metastasis. In addition, cytokine analysis of K14cre;EcdF/F;p53F/F mammary tumors demonstrated an increase in the IL17 pathway when compared to wild-type mammary glands. Subsets of T cells are known producers of IL17 and this pathway regulates neutrophil expansion indirectly. In accordance with this, K14cre;EcdF/F;p53F/F mice lacking the adaptive immune system displayed reduced IL17 levels and reduced circulating neutrophils. Current efforts are underway to determine whether T cells play a role in the pro-metastatic function of neutrophils. Together, these findings indicate that neutrophils are crucial for the establishment of breast cancer metastasis. Citation Format: Seth B. Coffelt, Chris W. Doornebal, Kelly Kersten, Metamia Ciampricotti, Cheei-Sing Hau, Kim Vrijland, Jorieke Weiden, Jos Jonkers, Karin E. de Visser. Neutrophils promote metastasis of invasive lobular carcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr A083.

The Effect of Electroacupuncture on Osteosarcoma Tumor Growth and Metastasis: Analysis of Different Treatment Regimens

Osteosarcoma is the most common malignant bone tumor found in children and adolescents and is associated with many complications including cancer pain and metastasis. While cancer patients often seek complementary and alternative medicine (CAM) approaches to treat cancer pain and fatigue or the side effects of chemotherapy and treatment, there is little known about the effect of acupuncture treatment on tumor growth and metastasis. Here we evaluate the effects of six different electroacupuncture (EA) regimens on osteosarcoma tumor growth and metastasis in both male and female mice. The most significant positive effects were observed when EA was applied to the ST-36 acupoint twice weekly (EA-2X/3) beginning at postimplantation day 3 (PID 3). Twice weekly treatment produced robust reductions in tumor growth. Conversely, when EA was applied twice weekly (EA-2X/7), starting at PID 7, there was a significant increase in tumor growth. We further demonstrate that EA-2X/3 treatment elicits significant reductions in tumor lymphatics, vasculature, and innervation. Lastly, EA-2X/3 treatment produced a marked reduction in pulmonary metastasis, thus providing evidence for EA's potential antimetastatic capabilities. Collectively, EA-2X/3 treatment was found to reduce both bone tumor growth and lung metastasis, which may be mediated in part through reductions in tumor-associated vasculature, lymphatics, and innervation.

Tumor-derived secretory clusterin induces epithelial–mesenchymal transition and facilitates hepatocellular carcinoma metastasis

Hepatocellular carcinoma (HCC) is the third most common cause of cancer mortality. Metastasis is the major concern that causes death in HCC. The goal of this study was to identify tumor-derived proteins in serum during HCC metastasis using an orthotopic xenograft tumor model and explore the role of key protein in HCC metastasis. Serum samples collected from HCCLM3-R metastatic HCC tumor model at specific stages of metastasis (1 wk, 3 wks and 6 wks) were subjected to iTRAQ labeling followed by 2DLC-ESI-MS/MS analysis. Twenty tumor-derived proteins were identified through human specific peptides. Secretory clusterin (sCLU), which was significantly upregulated during cancer progression and metastasis, was chosen for further study. The expression of sCLU was significantly higher in metastatic HCC cell lines and samples from metastatic HCC patients. ShRNA-mediated down-regulation of sCLU resulted in a reduced migratory capacity in HCC cell lines, as well as a reduction in pulmonary metastasis in vivo. Overexpression of sCLU in HepG2 cell line showed increased cell migratory ability. Further study found that sCLU contributed to HCC migration and epithelial–mesenchymal transition (EMT) in vitro, and metastasis in vivo. In addition, sCLU also plays an important role in the regulation of TGF-β1-smad3 signaling. These findings suggest that sCLU may promote HCC metastasis via the induction of EMT process and may be a candidate target for HCC therapy.

Allelic Variation and Differential Expression of the mSIN3A Histone Deacetylase Complex Gene Arid4b Promote Mammary Tumor Growth and Metastasis

Accumulating evidence suggests that breast cancer metastatic progression is modified by germline polymorphism, although specific modifier genes have remained largely undefined. In the current study, we employ the MMTV-PyMT transgenic mouse model and the AKXD panel of recombinant inbred mice to identify AT–rich interactive domain 4B (Arid4b; NM_194262) as a breast cancer progression modifier gene. Ectopic expression of Arid4b promoted primary tumor growth in vivo as well as increased migration and invasion in vitro, and the phenotype was associated with polymorphisms identified between the AKR/J and DBA/2J alleles as predicted by our genetic analyses. Stable shRNA–mediated knockdown of Arid4b caused a significant reduction in pulmonary metastases, validating a role for Arid4b as a metastasis modifier gene. ARID4B physically interacts with the breast cancer metastasis suppressor BRMS1, and we detected differential binding of the Arid4b alleles to histone deacetylase complex members mSIN3A and mSDS3, suggesting that the mechanism of Arid4b action likely involves interactions with chromatin modifying complexes. Downregulation of the conserved Tpx2 gene network, which is comprised of many factors regulating cell cycle and mitotic spindle biology, was observed concomitant with loss of metastatic efficiency in Arid4b knockdown cells. Consistent with our genetic analysis and in vivo experiments in our mouse model system, ARID4B expression was also an independent predictor of distant metastasis-free survival in breast cancer patients with ER+ tumors. These studies support a causative role of ARID4B in metastatic progression of breast cancer.

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

Use of Macrophages to Target Therapeutic Adenovirus to Human Prostate Tumors

New therapies are required to target hypoxic areas of tumors as these sites are highly resistant to conventional cancer therapies. Monocytes continuously extravasate from the bloodstream into tumors where they differentiate into macrophages and accumulate in hypoxic areas, thereby opening up the possibility of using these cells as vehicles to deliver gene therapy to these otherwise inaccessible sites. We describe a new cell-based method that selectively targets an oncolytic adenovirus to hypoxic areas of prostate tumors. In this approach, macrophages were cotransduced with a hypoxia-regulated E1A/B construct and an E1A-dependent oncolytic adenovirus, whose proliferation is restricted to prostate tumor cells using prostate-specific promoter elements from the TARP, PSA, and PMSA genes. When such cotransduced cells reach an area of extreme hypoxia, the E1A/B proteins are expressed, thereby activating replication of the adenovirus. The virus is subsequently released by the host macrophage and infects neighboring tumor cells. Following systemic injection into mice bearing subcutaneous or orthotopic prostate tumors, cotransduced macrophages migrated into hypoxic tumor areas, upregulated E1A protein, and released multiple copies of adenovirus. The virus then infected neighboring cells but only proliferated and was cytotoxic in prostate tumor cells, resulting in the marked inhibition of tumor growth and reduction of pulmonary metastases. This novel delivery system employs 3 levels of tumor specificity: the natural "homing" of macrophages to hypoxic tumor areas, hypoxia-induced proliferation of the therapeutic adenovirus in host macrophages, and targeted replication of oncolytic virus in prostate tumor cells.

Rate of Freeze Alters the Immunologic Response After Cryoablation of Breast Cancer

Cryoablation has garnered significant interest as a treatment for solid tumors including breast cancer for both its local effects and potential in stimulating an antitumor immune response. We sought to examine the impact that variances in technique might have on the immune response and examine the mechanism by which cryoablation may stimulate an antitumor immune response. Balb/c mice with established 4T1 mammary carcinomas were treated by cryoablation at either a high rate of freeze or low rate of freeze, or by surgical excision, after spontaneous metastases occurred. Tumor-draining lymph nodes (TDLN) were excised at 1 week for EliSPOT assay and immunophenotyping. Mice were followed after treatment for enumeration of pulmonary metastases and survival. Compared with surgical excision, cryoablation using a high freeze rate resulted in a significant increase in tumor-specific T cells in the TDLN, a reduction in pulmonary metastases, and improved survival. However, cryoablation using a low freeze rate resulted in an increase in regulatory T cells, a significant increase in pulmonary metastases, and decreased survival. Cryoablation of breast cancer in mice can generate a tumor-specific immune response that can eradicate systemic micrometastases and improve outcome compared with surgical excision; however, the technique used to freeze the tissue may alter the immune response from stimulatory to suppressive.

A phase II evaluation of aerosolized GM-CSF (AGM-CSF) plus standard I-MAP/ GM-CSF/MAP/ surgery/ irradiation in the reduction of pulmonary metastases (P-METS) in soft tissue sarcoma (STS) patients (PTS)

10058 Background: P-METs remain illusive with standard treatments for STS. AGM-CSF demonstrated tolerability with promising efficacy in reducing P-METS. We evaluated the 2-yr P-MET free rate in chemonaiive pts with extremity STS. Methods: ECOG PS 0/1 and Gr 3/4 primary STS of the limb girdle/extremities, were required. Treatment sequence: 2 cycles of IMAP (Ifosfamide, Mitomycin, Doxorubicin, Cisplatin) plus s.q. GM-CSF (preload d -6 to -3, d1–14); MAP (d0, 28) during irradiation (d1–35) plus AGM-CSF 250 mcg bid (d1–7, 15- 22, 28–35); surgery; post-op irradiation plus AGM-CSF 250 mcg bid (d1–7, 15–22, 28–35, 42–49). 6 of 35 pts with P-METS in ≤ 2 yrs implied lack of efficacy w.r.t. reducing P-METS. Results: 38 eligible pts were enrolled (20 male, median age 51 yrs, 24 PS 0). Median size of tumor 9 cm (2.3–26.7 cm).Location of tumors included: proximal extremity-16, distal extremity-11, and limb girdle-12. 79% received debulking surgery; 29 rendered disease-free. 38 pts are evaluable for toxicity (see table ). More common Gr 3+ events related to treatment appear below. 79% had Gr 4 neutropenia, despite s.q. GM-CSF. 6 pts have died, with 2.5 yrs median follow-up on survivors (range .4- 4.6). No treatment related fatalities occurred. 10 pts had P-METS ≤ 2 yrs. The estimated 2 yr P-MET free rate is 75% (95% CI 62–91). Conclusions: Although high, neutropenia was as expected. AGM-CSF failed to improve the 2 yr P-MET free rate in this group of STS pts. Other strategies need to be explored. Supported by NIH Grant CA15083–32 and Berlex Corporation. Max Severity (Gr 3+) [Table: see text] No significant financial relationships to disclose.

The effect of the flavonoid diosmin, grape seed extract and red wine on the pulmonary metastatic B16F10 melanoma.

To study the effect of different phenolic compounds and red wine on pulmonary metastatic melanoma. Swiss mice were inoculated with 500000 melanocytes B16F10 and given oral doses of diosmin, grape seed extract (GSE) and red wine. A macroscopic count was made of the metastatic nodules on the lung surface and a microscopic study by image analysis of five sections, calculating the implantation percentage and tumoral growth and invasion indices. Macroscopically, the group treated with diosmin showed the greatest reduction (52%) in the number of metastatic nodules compared with the control group, which was treated with ethanol, while GSE and red wine caused decreases of 26.07 and 28.81%, respectively. Microscopically, there was a decrease in the implantation percentage after the administration of diosmin (79.4%) and red wine (20.19%), and an increase of 2.12% after the administration of GSE, all relative to the ethanol-treated control. As regards the growth index, diosmin produced a reduction of 67.44% and red wine a reduction of 20.62%, while GSE again produced an increase (25.33%). The reductions in the invasion index were 45.23, 31.65 and 17.57% with diosmin, GSE and red wine, respectively. Diosmin originated the greatest reduction in pulmonary metastases, both at the macroscopic and microscopic levels.

Dendritic cell vaccine therapy by immunization with fusion cells of interleukin-2 gene-transduced, spleen-derived dendritic cells and tumour cells.

We examined the preventive and therapeutic effects of fusion cells prepared from spleen-derived dendritic cells (DCs) transduced with the interleukin-2 (IL-2) gene and QRsP fibrosarcoma cells in a mouse lung metastasis model. The IL-2 or LacZ gene was introduced into spleen-derived DCs using an adenoviral vector. Irradiated QRsP tumour cells were fused with IL-2 gene-transduced DCs (fusion/IL-2) or LacZ gene-transduced DCs (fusion/LacZ) by polyethylene glycol. These fusion cells expressed major histocompatibility complexes (MHC) class I and II, CD86, CD11c and CD8alpha. Splenocytes from mice vaccinated with fusion cells showed increased production of interferon-gamma (IFN-gamma) and cytotoxic T-lymphocyte (CTL) activity as compared with those vaccinated with DCs or tumour cells alone, and CTL levels were higher in fusion/IL-2-vaccinated mice than in fusion/LacZ-vaccinated mice. In our experiments on the protective and therapeutic effects on lung metastasis, mice vaccinated with fusion/IL-2 fusion/LacZ or fusion showed a significant reduction in pulmonary metastasis compared with those given DCs, tumour or phosphate-buffered saline. The introduction of the IL-2 gene into fusion cells produced more potent preventive and therapeutic effects. These results suggest that immunization with fusion cells prepared from spleen-derived DCs and tumour cells is capable of inducing preventive and therapeutic anti-tumour immunity against lung metastasis, and modification by the IL-2 gene may increase anti-tumour efficacy.

T140 analogs as CXCR4 antagonists identified as anti-metastatic agents in the treatment of breast cancer

A chemokine receptor, CXCR4, and its endogenous ligand, stromal cell-derived factor-1 (SDF-1), have been recognized to be involved in the metastasis of several types of cancers. T140 analogs are peptidic CXCR4 antagonists composed of 14 amino acid residues that were previously developed as anti-HIV agents having inhibitory activity against HIV-entry through its co-receptor, CXCR4. Herein, we report that these compounds effectively inhibited SDF-1-induced migration of human breast cancer cells (MDA-MB-231), human leukemia T cells (Sup-T1) and human umbilical vein endothelial cells at concentrations of 10–100 nM in vitro. Furthermore, slow release administration by subcutaneous injection using an Alzet osmotic pump of a potent and bio-stable T140 analog, 4F-benzoyl-TN14003, gave a partial, but statistically significant ( P≤0.05 ( t-test)) reduction in pulmonary metastasis of MDA-MB-231 in SCID mice, even though no attempt was made to inhibit other important targets such as CCR7. These results suggest that T140 analogs have potential use for cancer therapy, and that small molecular CXCR4 antagonists could potentially replace neutralizing antibodies as anti-metastatic agents for breast cancer.