Tea plant root extract (TRE) as an antineoplastic agent

The antitumour effect of tea plant root extract (TRE) has been evaluated against Ehrlich ascites carcinoma (EAC) in Balb-C mice. Significant increases of survival times of the TRE-treated, tumour-bearing mice have been confirmed repeatedly with respect to the control group. TRE inhibited the tumour cell growth and reversed the changes of haematological parameters consequent to tumour inoculation.     

The association between size of test chamber and patch test reaction: a statistical reanalysis

BACKGROUND: The effect of the tumour-bearing state and alterations in peritoneal immune function on the incidence of port-site and peritoneal metastases was investigated after laparoscopy with and without CO2 pneumoperitoneum. METHODS: A suspension of viable adenocarcinoma cells was introduced into the left upper quadrant of the peritoneal cavity of syngeneic tumour-bearing rats at laparotomy, laparoscopy with CO2, and gasless laparoscopy. Control rats did not have pre-existing tumours. A group of non-tumour-bearing rats were also injected intraperitoneally with endotoxin 4 h before intraperitoneal tumour cell injection. Six days later the peritoneal cavity and surgical wounds were examined for macroscopic evidence of implanted tumour. Peritoneal macrophages were obtained from tumour-bearing rats subjected to different laparoscopic procedures and the activation state measured following exposure to lipopolysaccharide in vitro. RESULTS: In the control rats, tumour implantation in the surgical wounds and peritoneum was significantly greater in the rats that had undergone laparoscopy with CO2. The presence of a pre-existing tumour was associated with increased tumour spread in all treatment groups and at most sites. Injection of endotoxin also resulted in increased tumour spread. Peritoneal macrophages from control and tumour-bearing rats who underwent laparoscopy with CO2 produced significantly less TNF-alpha in vitro, compared to gasless laparoscopy or laparotomy. CONCLUSIONS: Carbon dioxide insufflation enhances tumour spread and implantation. The underlying immune or metabolic status of the host, as influenced by the tumour-bearing state or modification of the peritoneal environment, also has a marked independent effect on tumour spread and implantation. The immune and metabolic status of the peritoneum including the extent of macrophage activation is implicated in this effect.     

Australian presidential address of the International Society for Cardiovascular Surgery. The society and the chapter, a short history

This study was designed to investigate the potential of shark cartilage extracts to inhibit the growth and metastatic spread of a murine solid tumour. The SCCVII carcinoma, implanted in the right rear foot of C3H mice, was used. Following tumour implantation, two different commercially available extracts of shark cartilage (Sharkilage and MIA Shark Powder) were dissolved in water and orally administered to the mice at doses that ranged from 5 to 100 mg per mouse. These injections were repeated on a daily basis for up to 25 days post-implantation of the primary tumour. Compared to non-drug-treated animals, daily administration of the shark cartilage extracts did not show any adverse toxicity (as measured by changes in body weight and lethality). More importantly, none of the shark cartilage doses tested had any retarding effect on the growth of the primary tumour, nor did they inhibit the development of metastases seen in the lungs of the tumour-bearing mice at autopsy. In conclusion, our results offer no support for the proposed use of shark cartilage extracts as an anti-cancer therapy.     

Growth of transplanted tumours in mice treated with macrophages and their products

The antitumour activity of peritoneal macrophages, added to tumour inocula (Winn test), was determined. Macrophages harvested from mice immunised with tumour, or from tumour-bearing mice, suppressed or inhibited tumour growth when in direct contact with tumour cells. Incubation of macrophages exhibiting antitumour activity with tumour cells yielded supernatant fluids capable of interfering with tumour growth. Consistent induction of antitumor activity required either addition of indomethacin to the incubation mixture, or collection of macrophages from immunised or tumour-bearing donors that had ingested indomethacin in the drinking water. Tumour growth was significantly inhibited when tumour inocula were suspended in supernatant fluid, or when mice were given several subcutaneous injections of supernatant prior to tumour transplantation.     

Changes in glutathione status and the antioxidant system in blood and in cancer cells associate with tumour growth in vivo

The relationship among cancer growth, the glutathione redox cycle and the antioxidant system was studied in blood and in tumour cells. During cancer growth, the glutathione redox status (GSH/GSSG) decreases in blood of Ehrlich ascites tumour-bearing mice. This effect is mainly due to an increase in GSSG levels. Two reasons may explain the increase in blood GSSG: (a) the increase in peroxide production by the tumour that, in addition to changes affecting the glutathione-related and the antioxidant enzyme activities, can lead to GSH oxidation within the red blood cells; and (b) an increase of GSSG release from different tissues into the blood. GSH and peroxide levels are higher in the tumour cells when they proliferate actively, however GSSG levels remain constant during tumour growth in mice. These changes associate with low levels of lipid peroxidation in plasma, blood and the tumour cells. The GSH/GSSG ratio in blood also decreases in patients bearing breast or colon cancers and, as it occurs in tumour-bearing mice, this change associates with higher GSSG levels, especially in advanced stages of cancer progression. Our results indicate that determination of glutathione status and oxidative stress-related parameters in blood may help to orientate cancer therapy in humans.     

Ex vivo generation of functional dendritic cells from mobilized CD34+ hematopoietic stem cells

Gene engineering to enhance tumour immunogenicity and elicit curative responses against established tumours and tumour recurrences has become an attractive prospect. Gene engineering enables new genes to be selectively inserted into the genome of a tumour cell, or the construction of new fusion plasmids coding tumour antigens and immunomodulatory molecules. The rationale behind current research is to enhance the immune recognition of tumour antigens through their association with the molecules on which immune recognition depends. The immunotherapy data obtained in many experimental tumour systems provide a realistic assessment of the potential and limits of this technological approach. Experimental vaccination of rodents has been shown to induce a significant immune memory, even against poorly immunogenic tumours, that can prevent tumour growth and cure initial metastases, but is poorly effective against established tumours. Its use in tumour prevention is a fresh dawning perspective.     

Interleukin-6 cDNA transfected Lewis lung carcinoma cells show unaltered net tumour growth rate but cause weight loss and shortened survival in syngeneic mice

HuIL-6 cDNA, cloned into a neomycin resistant conferring expression vector, BMGNeo, was transfected into Lewis Lung Carcinoma (LLC) cells. LLC cells (5 x 10(6) ml-1) transfected with IL-6 cDNA (LLC-IL6) secreted IL-6 into the culture supernatant at a concentration of 9.9 ng ml-1 within 48 h. When 1,000,000 of untransfected LLC, BMGNeo vector transfected LLC (LLC-Neo) or LLC-IL6 cells were transplanted into C57BL/6 mice subcutaneously, the mean +/- s.d. of survival times of these mice were 33.3 +/- 9.7, 34.3 +/- 7.1 and 17.0 +/- 3.1 days, respectively. The survival time of LLC-IL6 cells transplanted mice was significantly shorter than that of LLC (P < 0.01) or LLC-Neo (P < 0.01) cells transplanted mice without a measurable difference of tumour size. Plasma concentration of IL-6 steadily increased in LLC-IL6 transplanted mice. Body weight and serum albumin were significantly lower in LLC-IL6 transplanted mice than in LLC transplanted mice. Mouse IL-1 alpha and mouse TNF-alpha were not detected in the plasma of LLC-IL6 transplanted mice. These data suggested that secretion of IL-6 from LLC cells was unable to alter net tumour growth rate but rather caused a state similar to cachexia without detectable increase of IL-1 alpha and TNF-alpha in the plasma. This state may be responsible for the shortened survival of LLC-IL6 tumour-bearing mice.     

Antioxidant effects of propofol in human hepatic microsomes: concentration effects and clinical relevance

Parvoviruses of rodents are endowed with oncosuppressive properties. In particular, parvoviral infections protect host animals from spontaneous and chemical- or virus-induced tumour initiation in laboratory animals. The present study was undertaken to substantiate the capacity of parvovirus H-1 to inhibit therapeutically the growth of established tumours originating from human carcinoma cells implanted in recipient mice. To this end, quickly growing s.c. carcinomas were established by injection of human cervical carcinoma cells (HeLa) into immunodeficient (SCID) mice. Tumour-bearing mice subsequently were inoculated with H-1 at various multiplicities of infection. H-1 virus infection led to regression of tumours, the onset and efficiency of which were dose-dependent.     

Effect of lithium gamma-linolenate on the growth of experimental human pancreatic carcinoma

BACKGROUND: The lithium salt of gamma-linolenic acid (Li-GLA) is growth inhibitory to pancreatic cancer cells in vitro and is reported to prolong the survival of patients with pancreatic cancer. The effect of Li-GLA on the growth of human pancreatic carcinoma in vivo is not known. In this study the effect of parenterally administered Li-GLA on the growth of human pancreatic carcinoma in nude mice was tested. METHODS: Pancreatic tumours were produced in nude mice by subcutaneous implantation of MIA PaCa-2 cells. This cell line is sensitive to Li-GLA in vitro. Mice were randomly treated with intraperitoneal, intravenous or intratumoral Li-GLA. Each group also had controls. RESULTS: Both intravenous and intraperitoneal administration of Li-GLA had no significant effect on tumour growth or tumour phospholipid fatty acid composition. Intratumoral administration of Li-GLA was, however, associated with a significant antitumour effect. CONCLUSION: Within the limitations of this tumour model, the benefit seen with intravenous Li-GLA in patients with pancreatic carcinoma cannot be explained by tumour growth inhibition. Local administration appears to be more effective than intravenous or intraperitoneal therapy.     

Assessing the quality of life of children and adolescents with psychiatric disorders--a review

IP-10 is a member of the alpha or cysteine-X amino acid-cysteine (CXC) chemokine family of chemotactic cytokines. High levels of IP-10 expression have been detected in a number of chronic human inflammatory conditions, including psoriasis, a common inflammatory disease of the skin. IP-10 has been shown to chemoattract activated T cells, inhibit the proliferation of endothelial cells, and inhibit the growth of tumors in vivo. To determine the capacity of IP-10 to modulate the inflammatory response in vivo, we have created transgenic mice that constitutively express IP-10 from keratinocytes. These mice developed normally and, in general, did not spontaneously recruit leukocytes into the skin or other organs that expressed the transgene. In addition, the transgenic mice had a normal cutaneous contact hypersensitivity cellular immune response. However, IP-10 transgenic mice had an abnormal wound healing response characterized by a more intense inflammatory phase and a prolonged and disorganized granulation phase with impaired blood vessel formation. These results have demonstrated that IP-10 can inhibit the neovascularization associated with a physiological response in vivo and have revealed a novel biologic activity of IP-10 as an inhibitor of wound healing.     

In vivo activation and expansion of T cells by a bi-specific antibody abolishes metastasis formation of human melanoma cells in SCID mice

Bi-specific antibody fragments (bAB) are used in tumour therapy as a means to redirect and to strengthen effector cell function. It would be of great therapeutic advantage if, in addition, recruitment, expansion and the state of activity of effector cells are influenced by targeting through a bAB. This question was explored in the melanoma-bearing SCID mouse. The chemically coupled Fab' fragments of an anti-CD3 and an anti-p97 monoclonal antibody (MAB) were characterized in vitro for dual binding specificity and support of lymphokine-activated-killer-cell (LAKC) cytotoxicity towards a highly aggressive human melanoma line, which was significantly increased and exceeded levels of antibody-dependent cellular cytotoxicity observed in the presence of the anti-p97 MAB. The in vivo efficacy was tested in the SCID mouse: 5, 10 and 15 days after i.p. application of tumour cells, mice received LAKC (2 x 10(7)) together with bAB (150-100 microg). The application of bAB was repeated at days 20 and 25. Application of LAKC to melanoma-bearing SCID mice prolonged the mean survival time from 22 days of the untreated control group to 41 days. Anti-p97 did not exert any additive effect. In the presence of bAB, melanoma cells did not grow in 3 out of 8 mice. The mean survival time of the 5 mice developing tumours was 45 days. Importantly, none of the mice receiving bAB developed metastases, which were seen in 100% of animals receiving tumour cells or tumour cells plus LAKC or tumour cells plus LAKC plus anti-p97. As revealed by LAKC recovered from the SCID mice, the efficacy of the bAB was based on prolonged persistence of CD8-positive cells as well as on expansion and activation of CD4-positive cells, which was observed only in bAB-treated tumour-bearing mice. The efficiency in recruiting cytotoxic and, in particular, helper T cells suggests bAB as a valuable additive in immunotherapeutic treatment of melanoma patients.     

Presence of the nematode Physaloptera sibirica Petrow and Gorbunow 1931, parasite of carnivores, in the lerot Eliomys quercinus L. in the Alps

Radiolabelled sarcoma cells injected into the tail veins of normal rats were held up almost exclusively in the lung, and were not observed to pass through into the systemic circulation. Intramuscularly injected tumour cells were retained at the site of injection. Radioactivity was lost from both sites though more rapidly from the lung than from muscular tissue and was probably the result of tumour-cell death. Alveolar macrophages did not take part in the destruction of tumour cells in the lung. There was an increased rate of radiolabel loss from the lungs of hyperimmune, post-excision and tumour-bearing rats, as compared with normal rats. The destruction was immunologically specific; it was detected earlier, was more comprehensive in the hyperimmune and post-excision animals than in tumour-bearing animals, and correlated with the ability of the hyperimmune and post-excision animals to reject larger numbers of intravenous unlabelled tumour cells, than the tumour-bearing rats.     

In vivo pharmacology and anti-tumour evaluation of the tyrphostin tyrosine kinase inhibitor RG13022

Amplification and increased expression of many growth factor receptors, including the epidermal growth factor receptor (EGFR), has been observed in human tumours. One therapeutic strategy for overcoming EGF autocrine control of tumour growth is inhibition of EGFR protein tyrosine kinase (PTK). A series of low molecular weight molecules have been identified which inhibit the EGFR PTK in vitro and demonstrate antiproliferative activity against human cancer cell lines with high expression of EGFR. A significant growth delay in squamous cancer xenografts has been reported for one of these compounds, the tyrphostin RG13022. Based on these encouraging results, we sought to confirm the activity of RG13022 in vivo and relate the effects to the in vivo plasma disposition. RG13022 and three additional peaks were detected by HPLC following intraperitoneal administration of 20 mg kg-1 RG13022 in MF1 nu/nu mice. RG13022 demonstrated rapid biexponential elimination from plasma with a terminal half-life of 50.4 min. RG13022 plasma concentrations were less than 1 microM by 20 min post injection. A primary product was identified as the geometrical isomer (E)-RG13022. Both RG13022 and its geometrical isomer inhibited DNA synthesis in HN5 cells after a 24 h in vitro incubation (IC50 = 11 microM and 38 microM respectively). Neither RG13022 nor its geometrical isomer displayed significant cytotoxicity. RG13022 had no influence on the growth of HN5 tumours when administered chronically, starting either on the day of tumour inoculation or after establishment of tumour xenografts. The rapid in vivo elimination of RG13022 has potential significance to the development of this and other related tyrphostin tyrosine kinase inhibitors, as plasma concentrations fell below that required for in vitro activity by 20 min post injection. The lack of in vivo tumour growth delay suggests that a more optimal administration schedule for RG13022 would include more frequent injections or continuous administration. An improved formulation for RG13022 is therefore required before further development of this or other similar protein tyrosine kinase inhibitors can be made. Alternative strategies should also be sought which display longer lasting in vivo exposures.     

The effect of a suspension of brain cells from mice of varying age on the growth of tumors, transplanted under the capsule

Antitumour activity of cerebral cells at different stages of ontogenesis (embryonic, new-born, adult) has been studied. Researches have been carried out at killer-activity patterns in vitro with target-cells and tumour transplantation under mice kidney's capsule in vivo. It has been established that mice cerebral cells' suspension can decrease the tumour transplants' growth under kidney's capsule. Antiproliferative activity of embryonic and new-born mice cerebral cells was much higher than adult one. The kidney and liver new-born mice cells had no antiproliferative activity at all.     

Combined effects of angiostatin and ionizing radiation in antitumour therapy

Angiogenesis, the formation of new capillaries from pre-existing vessels, is essential for tumour progression. Angiostatin, a proteolytic fragment of plasminogen that was first isolated from the serum and urine of tumour-bearing mice, inhibits angiogenesis and thereby growth of primary and metastatic tumours. Radiotherapy is important in the treatment of many human cancers, but is often unsuccessful because of tumour cell radiation resistance. Here we combine radiation with angiostatin to target tumour vasculature that is genetically stable and therefore less likely to develop resistance. The results show an antitumour interaction between ionizing radiation and angiostatin for four distinct tumour types, at doses of radiation that are used in radiotherapy. The combination produced no increase in toxicity towards normal tissue. In vitro studies show that radiation and angiostatin have combined cytotoxic effects on endothelial cells, but not tumour cells. In vivo studies show that these agents, in combination, target the tumour vasculature. Our results provide support for combining ionizing radiation with angiostatin to improve tumour eradication without increasing deleterious effects.     

Modulation of the antitumor activity of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosoure a by O(6)-methyl-2'-deoxyguanosine--a new inhibitor of O(6)-alkylguanine-DNA-alkyltransferase

O6-Methyl-2'-deoxyguanosine (O6-MedG), a novel inhibitor of O6-alkylguanine-DNA alkyltransferase (O6-AGT), has been synthesized. The ability of O6-MedG to deplete the O6-AGT activity in leukemia L1210 and melanoma B16 cells in vivo has been studied. After intraperitoneal administration of O6-MedG to mice bearing leukemia L1210 or melanoma B16, the activity of O6-AGT in tumour cells decreased by 50%. Pretreatment of leukemia L1210 bearing mice with O6-MedG (200 mg/kg) 24 hours prior to ACNU (15 mg/kg) administration resulted in six out of seven 60-day survivors. Treatment of mice with ACNU (15 mg/kg) alone increased the life span by 200%. Treatment of melanoma B16 bearing mice with O6-MedG and 3 hours thereafter with ACNU resulted in a 50% inhibition of tumour growth, whereas the inhibiting effect of ACNU alone was 16%. There was no difference in leukemia growth when L1210/BCNU bearing mice were treated with O6-MedG followed by ACNU treatment. In vivo ACNU (15 mg/kg) produced a deep and prolonged inhibition of DNA, RNA and protein synthesis in leukemia L1210 cells. The DNA synthesis in leukemia L1210/BCNU cells was shown to recover more rapidly than in L1210 cells. The activities of DNA-polymerases alpha and beta and, especially, of O6-AGT were elevated in ACNU-resistant leukemia cells as compared with ACNU-sensitive cells. The activation of some repairing enzymes, such as O6-AGT, DNA-polymerases alpha and beta as well as increased levels of GSH may play a role in the development of drug resistance to ACNU.     

Effect of concentration on albumin diffusion in lung interstitium

The growth of a transplantable murine non-Hodgkin lymphoma tumour, developing either intraperitoneally as an ascites tumour or subcutaneously as a solid tumour, has been shown to be markedly diminished by including phytohaemagglutinin (PHA), a lectin present in raw kidney bean (Phaseolus vulgaris) in the diet. In NMRI mice fed PHA within the range 0.45-7.0 mg/g diet, tumours which developed during a 10 day period after subcutaneous injection of cells were about 35% of the dry weight of those in lactalbumin-fed (control) animals. The reduced rate of growth occurred in a dose-dependent manner within the range 0.45-3.5 mg/g diet. Based on these observations it has been suggested that a competition between the gut epithelium undergoing hyperplasia and the developing tumour may occur for nutrients from a common body pool, and this may be an important factor with regard to the observed initial low level of tumour growth following the feeding of a PHA-containing diet. Observations which showed that the level of hyperplasia of the small bowel in response to feeding the PHA diets was higher in non-injected mice compared to those which had been injected with tumour cells substantiated the concept of competition between gut and tumour for nutrients etc. required for growth. Experiments with a second murine tumour cell line (a plasmacytoma) in Balb/c mice gave similar results indicating that the effect of PHA was not restricted to a single tumour system.     

Distant metastasis facilitated by BCG: spread of tumour cells injected in the BCG-primed site

Tumour metastasis in BCG-pretreated mice was studied using a methylcholanthrene-induced fibrosarcoma in C3H/He mice. When tumour cells were injected into the BCG-primed site, distant metastasis occurred in the lungs and the popliteal lymph node, through this tumour did not metastasize in normal mice. Such metastases were increased in proportion to the number of tumour cells injected into the BCG-primed site, and developed soon after tumour challenge. Concomitant immunity developed well in the mice bearing such metastases, but did not inhibit metastatic growth. Experiments using 125I-labelled SRBC or tumour cells revealed that such cells egressed rapidly from the BCG-primed site. When the tumour was inoculated into the contralateral foot to the BCG-primed site, the incidence and the number of metastases was reduced. Furthermore, BCG infection induced an increase of platelet count. I.v. injection of this tumour induced marked thrombocytopenia in normal mice. Administration of pentoxifylline, a methylxanthine derivative before tumour challenge reduced such metastases. These findings suggest that the changes in peripheral blood, such as increased platelet count and increased release of tumour cells from the injection site, facilitated distant metastasis in BCG-pretreated mice.     

Effect of tocotrienols on the growth of a human breast cancer cell line in culture

The tocotrienol-rich fraction (TRF) of palm oil consists of tocotrienols and some alpha-tocopherol (alpha-T). Tocotrienols are a form of vitamin E having an unsaturated side-chain, rather than the saturated side-chain of the more common tocopherols. Because palm oil has been shown not to promote chemically-induced mammary carcinogenesis, we tested effects of TRF and alpha-T on the proliferation, growth, and plating efficiency (PE) of the MDA-MB-435 estrogen-receptor-negative human breast cancer cells. TRF inhibited the proliferation of these cells with a concentration required to inhibit cell proliferation by 50% of 180 microgram/mL whereas alpha-T had no effect at concentrations up to 1000 microgram/mL as measured by incorporation of [3H]thymidine. The effects of TRF and alpha-T also were tested in longer-term growth experiments, using concentrations of 180 and 500 microgram/mL. We found that TRF inhibited the growth of these cells by 50%, whereas alpha-T did not. Their effect on the ability of these cells to form colonies also was studied, and it was found that TRF inhibited PE, whereas alpha T had no effect. These results suggest that the inhibition is due to the presence of tocotrienols in TRF rather than alpha T.     

Keratinocyte growth factor administered before conditioning ameliorates graft-versus-host disease after allogeneic bone marrow transplantation in mice

Keratinocyte growth factor (KGF) is important in tissue repair and wound healing and its administration can abrogate chemical- and radiation-induced tissue damage in rodents. We investigated KGF as a therapeutic agent for the prevention of graft-versus-host disease (GVHD)-induced tissue damage, morbidity, and mortality in an established murine allogeneic bone marrow transplantation (BMT) model. B10.BR (H2(k)) recipient mice were lethally irradiated and transplanted with C57BL/6 (H2(b)) bone marrow (BM) with spleen cells (BMS) as a source of GVHD-causing T cells. KGF-treated mice (5 mg/kg/d subcutaneously days -6, -5, and -4 pre-BMT) receiving BMS exhibited better survival than those not receiving KGF (P =.0027). Cyclophosphamide (Cy), a common component of total body irradiation (TBI)-containing regimens, was administered to other cohorts of mice at a dose of 120 mg/kg/d intraperitoneally on days -3 and -2 before BMT. KGF-treated mice again exhibited a better survival rate than those not receiving KGF (P =.00086). However, KGF-treated recipients receiving TBI or Cy/TBI BMS were not GVHD-free, as shown by lower body weights compared with BM groups. GVHD target tissues were assessed histologically during a 38-day post-BMT observation period. KGF ameliorated GVHD-induced tissue damage in the liver, skin, and lung (completely in some recipients) and moderately so in the spleen, colon, and ileum, even with Cy conditioning. These studies demonstrate that KGF administration, completed before conditioning, has potential as an anti-GVHD therapeutic agent.