Forms Of Anticancer Therapy Research Articles

Measuring telomerase activity using TRAP assays.

Telomerase is a reverse transcriptase that consists of the telomerase reverse transcriptase (TERT) protein and the telomerase RNA component TERC which also harbors the template region for telomere synthesis. In its canonical function the enzyme adds single-stranded telomeric hexanucleotides de novo to the ends of linear chromosomes, telomeres, in telomerase-positive cells such as germline, stem- and cancer cells. This potential biochemical activity of telomerase can be measured with the help of a telomerase repeat amplification protocol (TRAP) which often includes a PCR amplification due to the low abundance of telomerase in most cells and tissues. The current chapter describes various TRAP methods to detect telomerase activity (TA) using gel-based methods, its advantages and deficits, how to perform an ELISA-based TRAP assay and how best to interpret its results. Since development of the TRAP assay in 1994, there have been numerous modifications and adaptations of the method from real-time PCR analysis, isothermal amplification and nanotechnology to CRISPR/Cas-based methods which will be briefly mentioned. However, it is not possible to cover all different TRAP methods and thus there is no comprehensiveness claimed by this chapter. Instead, the author describes various aspects of using TRAP assays including required controls, sample preparation, etc. in order to avoid pitfalls and set-backs in applying this rather complex and demanding technique. The TRAP assay is particularly important to support clinical diagnosis of cancer, analyze tumor therapy as well as to evaluate various approaches to inhibit TA as a form of anti-cancer therapy.

High-Dose Vitamin C for Cancer Therapy

In recent years, the idea that Vitamin C (Vit-C) could be utilized as a form of anti-cancer therapy has generated many contradictory arguments. Recent insights into the physiological characteristics of Vit-C, its pharmacokinetics, and results from preclinical reports, however, suggest that high-dose Vit-C could be effectively utilized in the management of various tumor types. Studies have shown that the pharmacological action of Vit-C can attack various processes that cancerous cells use for their growth and development. Here, we discuss the anti-cancer functions of Vit-C, but also the potential for the use of Vit-C as an epigenetic regulator and immunotherapy enhancer. We also provide a short overview of the current state of systems for scavenging reactive oxygen species (ROS), especially in the context of their influencing high-dose Vit-C toxicity for the inhibition of cancer growth. Even though the mechanisms of Vit-C action are promising, they need to be supported with robust randomized and controlled clinical trials. Moreover, upcoming studies should focus on how to define the most suitable cancer patient populations for high-dose Vit-C treatments and develop effective strategies that combine Vit-C with various concurrent cancer treatment regimens.

Decitabine potentiates efficacy of doxorubicin in a preclinical trastuzumab-resistant HER2-positive breast cancer models

Acquired drug resistance and metastasis in breast cancer (BC) are coupled with epigenetic deregulation of gene expression. Epigenetic drugs, aiming to reverse these aberrant transcriptional patterns and sensitize cancer cells to other therapies, provide a new treatment strategy for drug-resistant tumors. Here we investigated the ability of DNA methyltransferase (DNMT) inhibitor decitabine (DAC) to increase the sensitivity of BC cells to anthracycline antibiotic doxorubicin (DOX). Three cell lines representing different molecular BC subtypes, JIMT-1, MDA-MB-231 and T-47D, were used to evaluate the synergy of sequential DAC + DOX treatment in vitro. The cytotoxicity, genotoxicity, apoptosis, and migration capacity were tested in 2D and 3D cultures. Moreover, genome-wide DNA methylation and transcriptomic analyses were employed to understand the differences underlying DAC responsiveness. The ability of DAC to sensitize trastuzumab-resistant HER2-positive JIMT-1 cells to DOX was examined in vivo in an orthotopic xenograft mouse model. DAC and DOX synergistic effect was identified in all tested cell lines, with JIMT-1 cells being most sensitive to DAC. Based on the whole-genome data, we assume that the aggressive behavior of JIMT-1 cells can be related to the enrichment of epithelial-to-mesenchymal transition and stemness-associated pathways in this cell line. The four-week DAC + DOX sequential administration significantly reduced the tumor growth, DNMT1 expression, and global DNA methylation in xenograft tissues. The efficacy of combination therapy was comparable to effect of pegylated liposomal DOX, used exclusively for the treatment of metastatic BC. This work demonstrates the potential of epigenetic drugs to modulate cancer cells' sensitivity to other forms of anticancer therapy.

Modality of Radiotherapy and Overall Survival in Pediatric Diffuse Brainstem Gliomas: Implications for Resource-Constrained Settings.

Childhood diffuse brainstem glioma (dBSG) is a rare tumor with a poor prognosis. Any tumor-directed surgical intervention is difficult. Magnetic resonance imaging forms the mainstay of diagnosis and radiation therapy has remained the backbone of therapy. In this study, we compare the outcomes of conformal radiotherapy with conventional therapy in the context of resource-constrained settings. In this retrospective analysis, conducted between 2010 and 2019, all pediatric patients with a diagnosis of dBSG were analyzed. The survival data were calculated in months from the date of diagnosis. Survival differences between variables were compared using the Log-rank test and the risk of death was calculated using Cox regression analysis. A total of 20 patients (11 males, 55%) with a diagnosis of dBSG were included. Median age at diagnosis was 6.5 years. No surgical resection or biopsy was done in any patient. Fifteen (75%) patients received radiotherapy and only 4 (20%) patients received additional chemotherapy. Five (25%) patients did not receive any form of anti-cancer therapy. Median overall survival (OS) was 8 months (95% CI 5.2-10.8). Females were at a higher risk of death than males. Children treated with radiotherapy had a longer OS than untreated children; however, the modality of radiotherapy employed or the addition of chemotherapy did not affect the OS. Radiotherapy, irrespective of the modality, increases the survival of children with dBSG in resource-poor settings. Additionally, socioeconomic concerns need to be addressed in the management of these tumors, especially in the case of female children. Lay summaryChildhood diffuse brainstem glioma (dBSG) is a rare tumor with a poor prognosis. Any tumor-directed surgical intervention is difficult. Magnetic resonance imaging forms the mainstay of diagnosis and radiation therapy has remained the backbone of therapy. In this 10-year retrospective study, we compare the outcomes of conformal radiotherapy with conventional therapy in the context of resource-constrained settings. A total of 20 patients with a diagnosis of dBSG were included with a median age at diagnosis of 6.5 years (5.25-8.75). No surgical resection or biopsy was done in any patient. Fifteen (75%) patients received radiotherapy and only 4 (20%) patients received additional chemotherapy. Five (25%) patients did not receive any form of anti-cancer therapy. Median overall survival (OS) was 8 months (95% CI 5.2-10.8). Females were at a 3.4-fold (95% CI 1.0-12.1) higher risk of death than males. Children treated with radiotherapy had a longer OS than untreated children; however, the modality of radiotherapy employed or the addition of chemotherapy did not affect the OS. Radiotherapy, irrespective of the modality, increases the survival of children with dBSG in resource-poor settings. Additionally, socioeconomic concerns need to be addressed in the management of these tumors, especially in the case of female children.

Combining epigenetic drugs with other therapies for solid tumours - past lessons and future promise.

Epigenetic dysregulation has long been recognized as a key factor contributing to tumorigenesis and tumour maintenance that can influence all of the recognized hallmarks of cancer. Despite regulatory approvals for the treatment of certain haematological malignancies, the efficacy of the first generation of epigenetic drugs (epi-drugs) in patients with solid tumours has been disappointing; however, successes have now been achieved in selected solid tumour subtypes, thanks to the development of novel compounds and a better understanding of cancer biology that have enabled precision medicine approaches. Several lines of evidence support that, beyond their potential as monotherapies, epigenetic drugs could have important roles in synergy with other anticancer therapies or in reversing acquired therapy resistance. Herein, we review the mechanisms by which epi-drugs can modulate the sensitivity of cancer cells to other forms of anticancer therapy, including chemotherapy, radiation therapy, hormone therapy, molecularly targeted therapy and immunotherapy. We provide a critical appraisal of the preclinical rationale, completed clinical studies and ongoing clinical trials relating to combination therapies incorporating epi-drugs. Finally, we propose and discuss rational clinical trial designs and drug development strategies, considering key factors including patient selection, tumour biomarker evaluation, drug scheduling and response assessment and study end points, with the aim of optimizing the development of such combinations.

18F-FDG PET/CT evaluation of tumor response to the implantation of RENCA macrobeads (RMB) in phase I and II clinical trials [INDBB 10091] in advanced, treatment-resistant metastatic colorectal cancer (mCRC).

e15046 Background: RMB, a cytostatic, biological system form of anti cancer therapy have been used in Ph I & II clinical trials in mCRC w/ evidence of improved survival benefit & QOL. Evaluation of metastatic tumor response by standard CT RECIST criteria however has been unsatisfactory. We hypothesized that using 18F FDG PET/CT scan to evaluate tumor anatomy & metabolism could provide a more accurate picture of tumor response to RMB Methods: 48 mCRC pts (14, Ph 1; 34, Ph 2a) who failed available treatments were implanted intraperitoneally w/ RMB (8mb/kg). Physicals, biomarkers & lab evaluation were obtained at baseline & days 14-90, with PET CT imaging at baseline & day 90. PET scan was acquired 1 hour after FDG injection of 9.4 mCi. CT was used for attenuation correction. Correlation between 18F FDG PET SUVmax findings & CEA & or CA19-9 responses was assessed. Positive response was defined as ≥20% decrease post implant in CEA, CA19-9 & SUV. Only tumors w/ SUVmax ≥ 2.5 were evaluated. SUV measurements were made by 1 radiologist experienced in PET-CT scanning & SUV determination Results: 123 FDG positive mCRC lesions (39, Ph 1; 84 Ph 2a) were detected in 37 evaluable pts (14 m, 23 f; mean age 58.2; SUVmax 2.5-17.5). Of the 37 pts, 28 (76%) showed stabilization & or decreased FDG uptake (4 w/ frank necrosis) as well as stable/decreased CT tumor measurements. Pts w/ pulmonary lesions showed greater responses than those w/ hepatic lesions. 9 (24%) of 37 pts showed increased SUVs. 23 pts (62%) showed decrease in CEA & or CA 19-9 ≥ 20%. 17 pts (74%; 13 decrease, 4 central & peripheral necrosis) had correlation between decreased SUVs/necrosis & biomarkers decrease Conclusions: We conclude SUVs are useful in monitoring mCRC lesions response to RMB therapy. Changes in SUVs correlate w/ CEA & CA 19-9 changes. Taken together the combined data indicate anti tumor effect in these Ph 1/2a trials & offer preliminary support for our hypothesis that 18FDG can be useful in evaluating cell system therapies. Issues of SUVmax standardization & effects of intra tumor heterogeneity however must be considered. Further studies are merited & ongoing, including a planned Ph 3 trial Clinical trial information: NCT01053013; NCT00283075.

Review paper. Chemobrain in patients suffering from cancer based on the example of multiple myeloma

Abstract Introduction: The incidence rate of cancers emphasizes the necessity to investigate not only patients’ somatic ailments but also their psychosocial functioning as well as the need to raise the quality standards of cancer patients. The improvement of the quality of life is one of the major challenges of psycho-oncology, which is the science created in the interface of two disciplines: psychology and medicine. One of the important aspects of psycho-oncologists’ activity is the minimization of negative side-effects related to treatment, such as changes in patients’ cognitive functioning resulting from anti-cancer treatment. Objective: The aim of this work is to provide the reader with the knowledge concerning the phenomenon of chemobrain in a very special group of patients with hemato-oncologic tumour. Few researches related to this topic have confirmed the occurrence of cognitive deficits resulting from the cancer process, taken cytotoxic drugs, other forms of anti-cancer therapy and the activeness of biochemical compounds in patients with multiple myeloma. Methods: The author has done a literary review concerning the topic under study using the Google Scholar and EBSCO databases. The main part of this work consists of references to Polish and English research literature published after 2000. The review includes also classic works from the eighties and nineties of the 20th century. Results: The present work has been divided into several sections. The part devoted to explanation of the term chemobrain describes the evolution of its definition over the years. The second section - ‘Heterogeneity of the phenomenon - causes’ - underlines the influence of biochemical etiological factors, such as the impact of the activity of proinflammatory cytokines on the cognitive state of the patients suffering from tumour. Next part - ‘Chemobrain and multiple myeloma’ is devoted to the clinical characteristics of this cancer and to the descriptions of the selected methods of chemotherapy. The review of researches concerning the deteriorated cognitive functioning of patients with multiple myeloma in relation to the probable aetiology of this disease has been also presented. Conclusions: The review of Polish and English literature concerning the functioning of memory and attention processes in the patients suffering from multiple myeloma can serve as an inspiration for a search for objective biochemical factors conditioning the deterioration of cognitive processes of the patients undergoing anti-cancer treatment.

Опыт применения мультикиназного ингибитора регорафениб при метастатическом колоректальном раке

The data of the efficacy and safety regorafenib in the treatment of 7 patients with metastatic colorectal cancer (mCRC) refractory to treatment with cytostatics and monoclonal antibodies - blockers EGFR and VEGF were analyzed. The maximum anti-tumor effect in 1 patient had partial remission, in 6 - stabilization. The duration of progression-free period from start of treatment regorafenib ranged from 1.5 to 6 months. 3 patients continued antitumor therapy after progression, 3 - had the symptomatic therapy after progression, 1 - had stabilization within 4 months and continued therapy of regorafenib. Toxic effects of therapy were nausea, vomiting, diarrhea, complications of the skin, temperature reaction, increased blood pressure, dysphonia. The most clinically significant adverse events were changes in laboratory parameters in 3 patients (increase of ALT, AST and bilirubin), that resulted an interruption in the treatment and correction of the dose. The use of regorafenib in mCRC ensure adequate tumor control, and is characterized by mild toxicity that is relevant for pretreated patients resistant to other forms of anticancer therapy.

Ras-mediated modulation of pyruvate dehydrogenase activity regulates mitochondrial reserve capacity and contributes to glioblastoma tumorigenesis.

Even though altered metabolism representing a hallmark of cancer was proposed nearly a century ago, recent technological advances have allowed investigators to continue uncovering a previously unrecognized complexity of metabolic programs that drive tumorigenesis beyond that of aerobic glycolysis. The bioenergetic state of a diverse panel of glioblastoma models, including isogenic lines derived from a genetically engineered adult astrocytic mouse model and patient-derived glioblastoma stem cells, was determined at baseline and in stressed conditions. Mechanisms contributing to the discovered metabolic phenotypes were determined through molecular and chemical perturbation, and their biological consequences were evaluated in vivo and in patient samples. Attenuated mitochondrial reserve capacity was identified as a common metabolic phenotype in glioblastoma lines. This phenotype was linked mechanistically with the capacity of Ras-mediated signaling to inhibit pyruvate dehydrogenase (PDH) activity through downregulation of PDH phosphatase (PDP) expression. PDP1 repression was validated clinically in patient-derived samples, suggesting that aberrant cellular signaling typical of glioblastoma actively modulates PDH activity. This phenotype was reversed through both chemical and molecular perturbation. Restoration of PDH activity through stable expression of PDP1-impaired tumorigenic potential. These findings support the central role that PDH regulation plays as a downstream consequence of aberrant signaling associated with gliomagenesis and the scientific rationale to continue to develop and test clinical strategies designed to activate PDH as a form of anticancer therapy in glioblastoma.

Expression of PD-L1, PD-L2, PD-1 and CTLA4 in myelodysplastic syndromes is enhanced by treatment with hypomethylating agents

Blockade of immune checkpoints is emerging as new form of anticancer therapy. We studied the expression of PD-L1, PD-L2, PD-1 and CTLA4 mRNA expression in CD34+ cells from MDS, CMML and AML patients (N=124). Aberrant up-regulation (≥2 fold) was observed in 34%, 14%, 15% and 8% of the patients respectively. Increased expression of these 4 genes was also observed in PBMNC (N=61). The relative expression of PD-L1 from PBMNC was significantly higher in MDS (p=0.018) and CMML (p=0.0128) compared to AML. By immunohistochemical (IHC) analysis, PD-L1 protein expression was observed in MDS CD34+ cells, whereas stroma/non-blast cellular compartment was positive for PD-1. In a cohort of patients treated with epigenetic therapy, PD-L1, PD-L2, PD-1 and CTLA4 expression was upregulated. Patients resistant to therapy had relative higher increments in gene expression compared to patients that achieved response. Treatment of leukemia cells with decitabine resulted in a dose dependent up-regulation of above genes. Exposure to decitabine resulted in partial demethylation of PD-1 in leukemia cell lines and human samples. This study suggests PD-1 signaling may be involved in MDS pathogenesis and resistance mechanisms to HMAs. Blockade of this pathway can be a potential therapy in MDS and AML.

Management of toxicities associated with high-dose interleukin-2 and biochemotherapy

High-dose interleukin-2, administered as a single agent or in combination with antineoplastic agents, known as biochemotherapy, holds the promise of durable remissions for patients with metastatic renal cell carcinoma and metastatic melanoma. The toxicities arising from high-dose interleukin-2-based therapies affect every organ system, causing significant acute morbidity. Administration of high-dose interleukin-2-based therapies requires specialized care and knowledge because of the severity and uniqueness of toxicities compared with the toxicities encountered with other forms of anticancer therapy. However, the toxicities of high-dose interleukin-2-based therapies are predictable and manageable by vigilant monitoring and appropriate supportive care protocols. To maximize outcomes, both acute and delayed toxicities require vigilant monitoring and adroit symptom management. This review details the pathophysiology, monitoring parameters, and management strategies for patients receiving high-dose interleukin-2-based therapy, with a focus on new and important management principles.

Understanding the Role of MET Kinase in Cancer Therapy

Understanding the Role of MET Kinase in Cancer Therapy

Impact of radiation therapy on the oncolytic adenovirus dl520: Implications on the treatment of glioblastoma

Background and purpose Viral oncolytic therapy is emerging as a new form of anticancer therapy and has shown promising preclinical results, especially in combination with radio- and chemotherapy. We recently reported that nuclear localization of the human transcription factor YB-1 in multidrug-resistant cells facilitates E1-independent adenoviral replication. The aim of this study was to evaluate the combined treatment of the conditionally-replicating adenovirus dl520 and radiotherapy in glioma cell lines in vitro and in human tumor xenografts. Furthermore, the dependency of YB-1 on dl520 replication was verified by shRNA directed down regulation of YB-1. Methods and material Localization of YB-1 was determined by immunostaining. Glioma cell lines LN-18, U373 and U87 were infected with dl520. Induction of cytopathic effect (CPE), viral replication, viral yield and viral release were determined after viral infection, radiation therapy and the combination of both treatment modalities. The capacity of treatments alone or combined to induce tumor growth inhibition of subcutaneous U373 tumors was tested also in nude mice. Results Quantitative real-time PCR demonstrated that the shRNA-mediated down regulation of YB-1 is leading to a dramatic decrease in adenoviral replication of dl520. Immunostaining analysis showed that the YB-1 protein was predominantly located in the cytoplasm in the perinuclear space and less abundant in the nucleus. After irradiation we found an increase of nuclear YB-1. The addition of radiotherapy increased the oncolytic effect of dl520 with enhanced viral replication, viral yield and viral release. The oncolytic activity of dl520 plus radiation inhibited the growth of subcutaneous U373 tumors in a xenograft mouse model. Conclusions Radiation mediated increase of nuclear YB-1 in glioma cells enhanced the oncolytic potential of adenovirus dl520.

Actinomycosis of the jaws—histopathological study of 45 patients shows significant involvement in bisphosphonate-associated osteonecrosis and infected osteoradionecrosis

Actinomycosis of the jaws is a rare disease, which has been recently described in patients with infected osteoradionecrosis (IORN) and bisphosphonate-associated osteonecrosis (BON). We investigated our archive material for Actinomycosis of the jaws with special regard to underlying disease. Out of a total number of 45 patients with Actinomycosis, 43 (93.5%) suffered from BON (58.7%) or IORN (35.6%), while there were only 3 patients (6.7%) without anti-tumor treatment. In all cases, we found direct association of Actinomyces colonies with bone; in the surrounding medullary space, mixed inflammatory infiltrates with variable amounts of osteoclasts were a typical finding. Pseudoepitheliomatous hyperplasia occurred in 60.9% of patients. Cell-rich vessel obliteration was seen in less than 25.9% of BON patients, while hyalinized vessel obliteration was obtained in 37.5% of IORN patients. Additionally performed polymerase chain reaction (PCR) on paraffin-embedded and ethylene diamine tetracetic acid (EDTA)-decalcified tissue specimens confirmed the presence of Actinomyces israelii in seven of seven cases analyzed. We conclude that Actinomycosis of the jaws is a particular complication in patients with BON and/or IORN. Patients with Actinomycosis of the jaws during or after these forms of anti-cancer therapy are suggested to represent a distinct patient cohort with a relevant impairment of their general condition.

Loss of ataxia telangiectasia mutated– and Rad3-related function potentiates the effects of chemotherapeutic drugs on cancer cell survival

The diverse responses of human cells to various forms of DNA damage are controlled by a complex network of signaling proteins. There has been considerable interest in the components of this signaling apparatus as potential targets for new forms of anticancer therapy. In this report, we examine the contributions of an upstream signaling molecule, the ataxia telangiectasia mutated- and Rad3-related (ATR) protein kinase, to the resistance of cancer cells to DNA-damaging agents that are commonly used as anticancer therapeutics. Loss of ATR function in knock-in cancer cells strikingly enhanced the effects of several of the most commonly used therapeutic compounds, impeding the progression of the cell cycle and reducing long-term cancer cell survival. Loss of ATR function potentiated the toxicity of alkylating agents most strikingly, antimetabolites moderately, and double-strand break-inducing agents to a lesser extent. These results suggest that specific inhibition of ATR activity will be a valid strategy to increase the effectiveness of currently used modes of therapy.

Macrophage migration and gene expression in response to tumor hypoxia

Monocytes are recruited into tumors from the circulation along defined chemotactic gradients and they then differentiate into tumor-associated macrophages (TAMs). Recent evidence has shown that large numbers of TAMs are attracted to and retained in avascular and necrotic areas, where they are exposed to tumor hypoxia. At these sites, TAMs appear to undergo marked phenotypic changes with activation of hypoxia-inducible transcription factors, dramatically upregulating the expression of a large number of genes encoding mitogenic, proangiogenic and prometastatic cytokines and enzymes. As a consequence, high TAMs density has been correlated with increased tumor growth and angiogenesis in various tumor types. Since hypoxia is a hallmark feature of malignant tumors and hypoxic tumor cells are relatively resistant to radio- and chemotherapy, these areas have become a target for novel forms of anticancer therapy. These include hypoxia-targeted gene therapy in which macrophages are armed with therapeutic genes that are activated by hypoxia-responsive promoter elements. This restricts transgene expression to hypoxic areas, where the gene product is then released and acts on neighboring hypoxic tumor cells or proliferating blood vessels. In this way, the responses of macrophages to tumor hypoxia can be exploited to deliver potent antitumor agents to these poorly vascularized, and thus largely inaccessible, areas of tumors.

Esophageal cancer

Carcinoma of the esophagus and gastroesophageal junction continues to be an aggressive cancer with poor prognosis, despite improved surgical results and the potential benefit of combined multimodality regimens. Additional data seem to confirm the rising incidence of adenocarcinoma, although users of nonsteroidal anti-inflammatory drugs seem to have a decreased risk. Much attention is focused on detecting high-grade dysplasia and early carcinoma with promising results using red fluorescence after preceding 5-aminolevulinic acid (ALA) sensitization. Positron emission tomography made a major breakthrough and seems to be superior to computed tomography in detecting distant metastasis as well as lymph node metastasis. Endoscopic ablation of early carcinoma results in promising early results, but a major issue remains the EUS discrimination between Tis-T1a and T1b, as the latter is frequently associated with lymph node metastasis. In the field of molecular biology, research is unraveling the role of cadherins and catenins in the mechanism underlying cell adherence, cell movement, and progress toward tumor formation. Mutations of p53 are correlated with loss of apoptosis and form an early step in progress toward carcinoma as well as mutations of other tumor-suppressing genes (eg, p16 and Rb mutations). Detection of such mutations may become useful prognostic indicators, but illustrate the genetic polymorphism influencing the susceptibility to carcinoma. Several lines of evidence suggest that the stabilizing or overriding of p53 mutant cancer cells and restoration of the wild-type tumor suppressor gene p53 may improve results of DNA damaging treatment modalities. Further research in this field may lead to new forms of anticancer therapy.

In vitro inhibition of endothelial cell growth by the antiangiogenic drug AGM-1470 (TNP-470) and the anti-endoglin antibody TEC-11.

Angiogenesis plays a key role in tumor growth, progression and metastasis. The modulation of angiogenesis represents a potentially useful target for novel forms of anticancer therapy. Two such modulators are AGM-1470 (TNP-470, angioinhibin), which is a synthetic analog of the antibiotic fumagallin, and the monoclonal antibody TEC-11 to endoglin. We investigated the mechanisms of action of these modulators on human microvascular and macrovascular endothelial cells and on the transformed endothelial cell line ECV-304 in vitro. The administration of AGM-1470 or TEC-11 resulted in a significant inhibition of cell proliferation in all cell types used; this effect was reversible upon removal of these compounds from the culture medium. Furthermore, biochemical and morphological analyses showed that neither AGM-1470 or TEC-11 induce apoptosis. Both AGM-1470 and TEC-11 inhibited the production of urokinase-type plasminogen activator (u-PA), an enzyme involved in the early steps of neovascularization. Finally, the incubation of endothelial cells with both AGM-1470 and TEC-11 did not produce an additive effect on growth cell inhibition, apoptosis or u-PA production. Since both AGM 1470 and TEC-11 inhibit crucial events such as endothelial cell growth and protease production, our results provide a basis for their therapeutic use as angiostatic molecules in cancer.

Immune responses to an oral administration of OK-432 in the aged subjects without malignancy

OK-432, one of the so-called biological response modifiers (BRMs), has been reported to restore cellular and humoral immune responses in tumor-bearing individuals. However, since host immune responses in tumor-bearing individuals are modified by development of disease, by application of various forms of anticancer therapy, surgical operation, and by radiation therapy, it is sometimes impossible to evaluate accurately the effect of these nonspecific BRM restoring impaired immune response in patients with malignancy. Avoiding this problem, we studied the effect of BRM on host immune responses in the aged individuals without malignancy, who had shown decreased cellular immunity detected by PPD and PHA skin tests and in vitro blastoid transformation test of lymphocytes by PHA. Although OK-432 is used widely by intradermal or intramuscular injections, it is more convenient for the patients to receive oral administration than intramuscular injection having the side effects such as chill and fever.Five KE or 20 KE of OK-432 was orally given three times a week for 1 month to the aged patients without malignancy who showed decreased skin responses to PPD and PHA. Oral adminstration of 5 KE of OK-432 evoked an increased skin response to PPD except 2 patients. PPD skin response was much more increased by the oral administration of 20 KE of OK-432, and the increased responsiveness was detected even 2 months after withdrawal of OK-432. There was same tendency in the skin response to PHA. The increased skin reaction to SuPS (lipopolysaccharide fraction of Streptococcus pyogenes Su strain) was observed in the one group of patients treated with 5 KE of OK-432, while there was no significant increased response by oral administration of 20 KE of OK-432.It was concluded that the activation of non-specific host immune responses assessed by the skin tests used by us could be evoked by the oral administration of OK-432 as well as intramuscular injection.