Antitumor effect of PSK at a distant site: inductions of interleukin-8-like factor and macrophage chemotactic factor in murine tumor

Identification and Analysis of Anticancer Therapeutic Targets from the Polysaccharide Krestin (PSK) and Polysaccharopeptide (PSP) Using Inverse Docking

The natural compounds PSK and PSP have antitumor and immunostimulant properties. These pharmacological benefits have been documented in vitro and in vivo, although there is no information in silico which describes the action mechanisms at the molecular level. In this study, the inverse docking method was used to identify the interactions of PSK and PSP with two local databases: BPAT with 66 antitumor proteins, and BPSIC with 138 surfaces and intracellular proteins. This led to the identification interactions and similarities of PSK and the AB680 inhibitor in the active site of CD73. It was also found that PSK binds to CD59, interacting with the amino acids APS22 and PHE23, which coincide with the rlLYd4 internalization inhibitor. With the isoform of the K-RAS protein, PSK bonded to the TYR32 amino acid at switch 1, while with BAK it bonded to the region of the α1 helix, while PSP bonded to the activation site and the C-terminal and N-terminal ends of that helix. In Bcl-2, PSK interacted at the binding site of the Venetoclax inhibitor, showing similarities with the amino acids ASP111, VAL133, LEU137, MET115, PHE112, and TYR108, while PSP had similarities with THR132, VAL133, LEU137, GLN118, MET115, APS111, PHE112, and PHE104.

In vitro and in vivo anti-tumor effects of Astragalus membranaceus

Astragalus membranaceus, a commonly used Chinese medicinal plant, has been shown to be capable of restoring the impaired T cell functions in cancer patients. In this study, the in vitro and in vivo anti-tumor effects of A. membranaceus were investigated. Five bioactive fractions were isolated from the root of A. membranaceus, the fraction designated as AI was found to be the most potent among the five fractions with respect to its mitogenicity on murine splenocytes. Besides investigating the cytostatic effect of AI, its activities on macrophage function, tumor necrosis factor production, induction of lymphokine-activated killer cell and tumor cell differentiation were also examined. The macrophage-like tumors and the myeloid tumors were found to be more sensitive to the cytostatic activity of AI, whereas the fibroblast-like tumors and the mouse Ehrlich ascites tumor appeared to be relatively resistant. Moreover, AI could effectively suppress the in vivo growth of syngeneic tumor in mice. Results showed that murine macrophage pretreated with AI had increased in vitro and in vivo cytostatic activities towards MBL-2 tumor. AI could also act as a priming agent for tumor necrosis factor production in tumor-bearing mice. Preincubation of mouse splenocytes with AI could induce in vitro lymphokine-activated killer-like activity towards WEHI-164 cell. Furthermore, AI was able to induce monocytic differentiation of both human and murine cells in vitro. AI administered in vivo could even partially restore the depressed mitogenic response in tumor-bearing mice. Collectively, the results showed that A. membranaceus could exhibit both in vitro and in vivo anti-tumor effects, which might be achieved through activating the anti-tumor immune mechanism of the host.

Identification of amino acid residues critical for LD78beta, a variant of human macrophage inflammatory protein-1alpha, binding to CCR5 and inhibition of R5 human immunodeficiency virus type 1 replication

In an attempt to determine which amino acid(s) of LD78beta, a variant of human macrophage inflammatory protein-1alpha, plays a critical role in the interaction with CCR5, we generated six LD78beta variants with an amino acid substituted to Ala at the NH(2) terminus of LD78beta. There was no significant difference in eliciting Ca(2+) flux and chemotaxis among the variants with the exception of LD78beta(T9A) showing a substantially reduced activity. The comparative order for human immunodeficiency virus type 1 (HIV-1) replication inhibition was: LD78beta(P8A) > LD78beta(D6A) > LD78beta(WT), LD78beta(L3A) > LD78beta(T7A), LD78beta(P2A) > LD78beta(T9A). In binding inhibition assays of LD78beta variants using 2D7 monoclonal antibody and (125)I-labeled macrophage inflammatory protein-1alpha, the comparative order was: LD78beta(P8A), LD78beta(D6A) > LD78beta(WT) > LD78beta(L3A) > LD78beta(T7A) > LD78beta(T9A), LD78betaP2A). The order for CCR5 down-regulation induction was comparable to that for binding inhibition. The present data suggest that Pro-2, Asp-6, Pro-8, and Thr-9 are critical for LD78beta binding to CCR5 and HIV-1 replication inhibition, and that LD78beta binding to CCR5, regardless of affinity, is sufficient for the initial signal transduction of LD78beta, whereas the greater anti-HIV-1 activity requires the greater magnitude of binding. The data also suggest that LD78beta variants with appropriate amino acid substitution(s) such as LD78beta(D6A) and LD78beta(P8A) may represent effective chemokine-based anti-HIV-1 therapeutics while preserving LD78beta-CCR5 interactions.

Effects of poly(ethyleneglycol)-modified hemoglobin vesicles on N-formyl-methionyl-leucyl-phenylalanine-induced responses of polymorphonuclear neutrophils in vitro

[Poly(ethyleneglycol)]-modified hemoglobin vesicles (PEG-HbV), a type of encapsulated hemoglobin, have been developed as artificial oxygen carriers and it is important to evaluate their blood compatibility. We studied the effects of PEG-HbV on human polymor phonuclear neutrophils (PMNs) in vitro, focusing on the functional responses to N-formyl-methionyl-leucyl-phenylalanine (fMLP) as an agonist. The pretreatment of the PMNs with PEG-HbV up to a concentration of 60 mg/dl Hb did not affect the fMLP-triggered chemotactic activity. In parallel to these results, the fMLP-induced upregulation of CD11b (Mac-1) levels on the PEG-HbV-pretreated PMNs was comparable to that of untreated cells. Furthermore, the pretreatment of the PMNs with the PEG-HbV even at 600 mg/dl Hb did not affect the gelatinase B (Matrix methalloproteinase-9 (MMP-9)) release, suggesting that the fMLP-induced release of secondary and tertiary granules was normal. In addition, the fMLP-triggered superoxide production of the PMNs was unchanged by the pretreatment with the PEG-HbV at 600 mg/dl Hb. Thus, these results suggest that PEG-HbV, at the concentrations studied, have no aberrant effects on the fMLP-triggered functions of human PMNs.

Gastric cancer in Asia: progress and controversies in surgical management

Considerable controversy surrounds the management of gastric cancer and this has largely overshadowed recent progress in our understanding of the epidemiology and molecular pathogenesis of the disease, and improvements in diagnostic and staging techniques. Differences identifiable in the molecular pathogenesis of the 'intestinal' and 'diffuse' types of gastric cancer may help to unravel the biological behaviour of variants and ultimately influence therapeutic strategies. Endoscopic ultrasound is well established as being accurate for T staging and the introduction of laparoscopy, with or without ultrasound, is obviating unnecessary laparotomy in non-bleeding, non-obstructed patients. Controversies in surgery encompass the role of laparoscopic surgery in early gastric cancer, the extent of lymphadenectomy including para-aortic nodal dissection, resection of en bloc contiguous organ involvement, pancreatosplenectomy, left upper abdominal evisceration, and modes of reconstruction (pylorus-preserving gastrectomy, pouch formation) to enhance quality of life. Whereas adjuvant chemotherapy does not impact favourably on survival, emphasis has now shifted to neoadjuvant (induction) chemotherapy to downstage the disease. Preoperative regional chemotherapy and intra-operative hyperthermic chemotherapy or irradiation may prove to be of benefit in patients with resectable disease, but some scepticism still exists as to the usefulness of biological response modifiers (e.g. OK432, PSK) for adjuvant treatment. Ethical issues relating to cultural differences in Asia sometimes mitigate against adequate trial design (e.g. a surgery-alone control group or a no adjuvant therapy treatment group may be considered inappropriate) and this has understandably hindered acceptance in Western countries of the value of current management practices in Asia. These issues and the need for ongoing well-conducted randomized trials with prospective subset analysis are now being addressed.

Circulating promyelocytes and low levels of CD16 expression on polymorphonuclear leukocytes accompany early-onset periodontitis

Early-onset periodontitis (EOP) is characterized by rapidly progressive alveolar bone loss, chemotactic defects of neutrophils, and significant familial aggregation. We found immature myeloid lineage cells, defined as promyelocytes, in the peripheral blood in patients with EOP. A hematological examination of peripheral blood cells showed normal reference values regarding cell proportions. Flow cytometry revealed significantly lower expression of CD16, a glycosylphosphatidylinositol (GPI)-anchored protein, on peripheral neutrophils in patients compared with those in age- and sex-matched healthy controls, whereas the levels of CD11a and CD11b expression were similar. The chemotactic response of neutrophils was lower toward not only formyl-methionyl-leucyl-phenylalanine but also complement fragment C5a than that of healthy controls. The expression of another GPI-anchored protein, CD14, was equally expressed by controls and patients. Therefore, the low level of CD16 expression was not due to the incomplete synthesis of the GPI anchor. GPI anchors of CD16 on neutrophils from controls and patients were both partially resistant to phosphatidylinositol-specific phospholipase C. The presence of promyelocytes in peripheral blood, low expression of CD16, and low chemotactic response of neutrophils suggest that patients with EOP have an abnormal maturation system in myeloid lineage cells in the bone marrow, which may be associated with the onset and course of EOP.

Immunomodulatory and anti-tumour polysaccharides from medicinal plants

Many Chinese medicinal plants have immunomodulatory and anti-tumour activities. Most of the anti-tumour activities of these Chinese herbs are probably due to their immunostimulating polysaccharide components. A general scheme for the isolation and purification of the bioactive polysaccharides from naturally occurring medicinal plants is described. Hot-water extraction followed by various chromatographic methods are usually used to purify the bioactive polysaccharides. The different fractions separated from Chinese medicinal plants show a range of immunomodulatory and anti-tumour activities. The analytical methods used for monosaccharide sequence determination and structural elucidation of the bioactive polysaccharides are described, as are the tests used to evaluate their immunopharmacological activities, both in vitro and in vivo. The purification, characterization and structural elucidation of immunomodulatory polysaccharides from medicinal plants may have important implications in the immunotherapy of cancer and in the treatment of various other diseases.

Analysis of effector T cells against the murine syngeneic tumor MethA in mice orally administered antitumor polysaccharide SPR-901

The growth of MethA tumor was significantly inhibited by oral administration of the alpha-glucan SPR-901 in BALB/c (+/+) mice but not in nude mice. Mice treated orally with SPR-901 exhibited an augmentation of antigen-specific resistance against rechallenge with the tumor cells. The tumor-neutralizing activity of regional lymph node cells from MethA-bearing mice against the tumor was augmented by oral administration of SPR-901. The tumor-neutralizing activity of lymph node cells from SPR-901-treated mice mainly appeared in Lyt2+ cells. Furthermore, lymphokine-activated killer activity of these cells was enhanced by administration of SPR-901. The antitumor effect of SPR-901 was abrogated in mice depleted of either L3T4+ or Lyt2+ cells, and in cyclosporin-A-treated mice. These results suggest that Lyt2+ cells are important effector cells in MethA-bearing mice orally administered SPR-901 and that functional exertion of both Lyt2+ and L3T4+ T cells is necessary for the antitumor effect of orally administered SPR-901 in vivo.

Antitumor effect of intratumoral administration of biological response modifiers: induction of immunosuppressive acidic protein, a type of alpha 1-acid glycoprotein, in mice

The antitumor effects of biological response modifiers (BRMs) in an experimental mouse model, the "double grafted tumor system" were analyzed. Male BALB/c mice received simultaneous inoculations of Meth-A fibrosarcoma cells on the right flank (10(6) cells) and left flank (2 x 10(5) cells) on day 0, and BRMs were injected intratumorally into the right tumor on days 3, 4 and 5. PSK (a protein-bound polysaccharide preparation), interleukin-1 (IL-1) and cepharanthin (CR) cured not only the right, but also the left, non-treated tumor in a double grafted tumor system. OK-432 (a Streptococcus preparation) and BCG and tumor necrosis factor (TNF) cured the right tumor and inhibited the growth of the left tumor. Lentinan (a polysaccharide preparation) and IL-6 inhibited neither the right nor the left tumor. Immunosuppressive acidic protein (IAP) in serum was increased transiently soon after intradermal injection of PSK, CR, OK-432 and TNF in BALB/c mice. Lentinan, however, did not induce IAP. IAP in serum was gradually increased after intradermal inoculation of Meth-A tumor in BALB/c mice. The biochemical difference between PSK-induced IAP (early, inflammatory IAP) and Meth-A-induced IAP (late, tumor-induced IAP) was investigated by crossed affinity immunoelectrophoresis with concanavalin A. IAP of murine serum was separated into 4 peaks. IAP in normal mouse was rich in high-mannose type sugar chain (Peak 3) and contained no hybrid-type sugar chain (Peak 4), which was present in inflammatory and tumor-induced IAP. Inflammatory IAP was rich in biantennary sugar chain (Peak 2) and tumor-induced IAP was rich in tri-tetraantennary sugar chain (Peak 1).

Mitogenic and tumor necrosis factor producing activities of Pseudostellaria heterophylla

Separation of mitogenic fraction (PH-I) from Pseudostellaria heterophylla and characterization of its biological activities were investigated. PH-I was isolated as an alcohol-insoluble fraction from the hot water extract obtained by heating the roots of P. heterophylla in water at 80 degrees C for 4 h. It is a water-soluble substance consisting of mainly carbohydrates (56.8%) and a small amount of proteins (7.6%). The incorporation of tritiated thymidine into the DNA of murine spleen lymphocytes could be stimulated by PH-I in a dose-dependent manner. PH-I could act as a priming agent for the release of tumor necrosis factor (TNF) in mice. Moreover, PH-I exhibited potent anti-tumor activities against Ehrlich ascites tumor (EAT) cells in vivo but not in vitro.

Antitumor effect of PSK at a distant site: tumor-specific immunity and combination with other chemotherapeutic agents

The antitumor effect of PSK, a Coriolus preparation, was analyzed with the double grafted tumor system in which BALB/c mice received intradermal inoculations of syngeneic Meth-A fibrosarcoma in the right (primary tumor, 10(6) cells) and left (distant tumor, 2 x 10(5) cells) flanks. Intratumoral administration of PSK significantly inhibited the growth of not only the right but also the left tumor. PSK also inhibited the growth of a methylcholanthrene-induced fibrosarcoma BAMC-1, and a methylurethane-induced adenocarcinoma Colon 26 in the double grafted tumor system of syngeneic BALB/c mice. However, when the left distant tumor was different from the right Meth-A tumor, the intratumoral administration of PSK in the right tumor was unable to inhibit the growth of the left BAMC-1 or RL male-1 tumor. The PSK-induced immunity, therefore, is tumor-specific and T lymphocytes may play an important role in antitumor memory function. The enhancement of concomitant immunity by PSK treatment was completely impaired by previous intravenous administration of an alkylating agent, cyclophosphamide (CY). The enhancement of sinecomitant immunity by PSK treatment was also impaired by previous CY intravenous administration. The antitumor effect of PSK was suppressed by previous intravenous administration of another alkylating agent, ACNU. It is possible that alkylating agents suppress the function of effector T cells and granulocytes which are very important for the antitumor immune cascade reaction due to PSK treatment. On the other hand, the antitumor effect of PSK was enhanced by previous intravenous administration of an anti-metabolite, 5-fluorouracil.

High endothelin-1 immunoreactivity in Crohn's disease and ulcerative colitis

Both immunological hypersensitivity and vascular abnormalities have been implicated in the pathogenesis of inflammatory bowel disease. In an attempt to link the two hypotheses, we sought evidence of local production of endothelin-1, a potent vasoconstrictor, in patients with Crohn's disease and ulcerative colitis. An immunohistochemical method was used to detect endothelin-1 in tissue samples from sixteen Crohn's disease patients, nine ulcerative colitis patients, and thirteen controls. In the controls, positively staining cells were infrequent in both lamina propria (mean 0.9% of total cells, 95% confidence interval 0.1-1.7%) and submucosa (2.3%, 0.4-4.1%). The percentage of endothelin-immunoreactive cells was significantly higher in the two disease groups than in the controls. Among the Crohn's disease patients, there were more immunoreactive cells in the submucosa than in the lamina propria (19.1%, 15.2-22.1% vs 12.3%, 8.1-16.5%; p less than 0.001), whereas the converse was true for the ulcerative colitis group (8.6%, 1.1-16.1% vs 24.4%, 14.1-34.6%; p less than 0.001). Immunoreactive macrophage aggregates around submucosal blood vessels were common in samples from Crohn's disease patients. Endothelin concentrations, measured by radioimmunoassay, in supernatants of homogenised tissue samples were significantly higher in Crohn's disease and ulcerative colitis than in controls. We suggest that local endothelin production by inflammatory cells may contribute to vasculitis in chronic inflammatory bowel disease by inducing intestinal ischaemia through vasoconstriction.