Protein-bound polysaccharide PSK inhibits tumor invasiveness by down-regulation of TGF-beta1 and MMPs

Research Progress on the Mechanisms of Polysaccharides against Gastric Cancer

Gastric cancer is a common type of cancer that poses a serious threat to human health. Polysaccharides are important functional phytochemicals, and research shows that polysaccharides have good anti-gastric cancer effects. We collated all relevant literature published from 2000 to 2020 and found that more than 60 natural polysaccharides demonstrate anti-gastric cancer activity. At the present, the sources of these polysaccharides include fungi, algae, tea, Astragalus membranaceus, Caulis Dendrobii, and other foods and Chinese herbal medicines. By regulating various signaling pathways, including the PI3K/AKT, MAPK, Fas/FasL, Wnt/β-catenin, IGF-IR, and TGF-β signaling pathways, polysaccharides induce gastric cancer cell apoptosis, cause cell cycle arrest, and inhibit migration and invasion. In addition, polysaccharides can enhance the immune system and killing activity of immune cells in gastric cancer patients and rats. This comprehensive review covers the extraction, purification, structural characterization, and mechanism of plant and fungal polysaccharides against gastric cancer. We hope this review is helpful for researchers to design, research, and develop plant and fungal polysaccharides.

In Vitro Anti-proliferative and Anti-invasive Effect of Polysaccharide-rich Extracts from Trametes Versicolor and Grifola Frondosa in Colon Cancer Cells

Colorectal cancer (CRC) is one of leading causes of mortality in western countries and novel treatment strategies are required. The medicinal application of mushrooms has been used in traditional medicine in many oriental countries. Polysaccharide-rich extracts obtained from certain medicinal mushroom species have shown antitumor effects in different experimental models. In the present study, we have developed polysaccharide-rich extracts from Trametes versicolor (TV) and Grifola frondosa (GF) fruit bodies. We aim to evaluate the anticancer effects of these polysaccharide-rich extracts in LoVo and HT-29 human colon cancer cells. The in vitro effects were determined by cytotoxicity assay, proliferation assay, wound healing assay and invasion assay. Moreover, the effect on anchorage independent-cell growth was also determined. Our results showed that TV and GF extracts did inhibit human colon cell proliferation and induce cytotoxicity. Furthermore, both fungal extracts significantly inhibited oncogenic potential, cell migration and invasion in colon cancer cells. In addition, extracts induce a more epithelial phenotype, observed by phase contrast images, together with an increase expression of the E-cadherin epithelial marker, detected by western-blotting analyses. Moreover, by using gelatin zymography assays, it was detected a decrease of MMP-2 enzyme activity, a crucial metalloproteinase important for the degradation of the extracellular matrix. Finally, the combination of the extracts with one the most clinical used agents for colorectal cancer, 5-fluorouracil, increases cell cytotoxicity. Taken together our results underscore a potential antitumor effect of polysaccharide-rich extracts obtained from TV and GF in human colon cancer cells lines. These finding may contribute to the reported health effects of fungal extracts.

Long noncoding RNA MRCCAT1 promotes metastasis of clear cell renal cell carcinoma via inhibiting NPR3 and activating p38-MAPK signaling

Background

Recent evidences showed that long noncoding RNAs (lncRNAs) are frequently dysregulated and play important roles in various cancers. Clear cell renal cell carcinoma (ccRCC) is one of the leading cause of cancer-related death, largely due to the metastasis of ccRCC. However, the clinical significances and roles of lncRNAs in metastatic ccRCC are still unknown.

Methods

lncRNA expression microarray analysis was performed to search the dysregulated lncRNA in metastatic ccRCC. quantitative real-time PCR was performed to measure the expression of lncRNAs in human ccRCC samples. Gain-of-function and loss-of-function experiments were performed to investigate the biological roles of lncRNAs on ccRCC cell proliferation, migration, invasion and in vivo metastasis. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and western blot were performed to explore the molecular mechanisms underlying the functions of lncRNAs.

Results

The microarray analysis identified a novel lncRNA termed metastatic renal cell carcinoma-associated transcript 1 (MRCCAT1), which is highly expressed in metastatic ccRCC tissues and associated with the metastatic properties of ccRCC. Multivariate Cox regression analysis revealed that MRCCAT1 is an independent prognostic factor for ccRCC patients. Overexpression of MRCCAT1 promotes ccRCC cells proliferation, migration, and invasion. Depletion of MRCCAT1 inhibites ccRCC cells proliferation, migration, and invasion in vitro, and ccRCC metastasis in vivo. Mechanistically, MRCCAT1 represses NPR3 transcription by recruiting PRC2 to NPR3 promoter, and subsequently activates p38-MAPK signaling pathway.

Conclusions

MRCCAT1 is a critical lncRNA that promotes ccRCC metastasis via inhibiting NPR3 and activating p38-MAPK signaling. Our results imply that MRCCAT1 could serve as a prognostic biomarker and therapeutic target for ccRCC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0681-0) contains supplementary material, which is available to authorized users.

Protein-bound polysaccharide K suppresses tumor fibrosis in gastric cancer by inhibiting the TGF-β signaling pathway

Peritoneal carcinomatosis (PC) is the most frequent metastatic pattern of gastric cancer and its prognosis is extremely poor. PC is characterized by rich fibrosis and the development of obstructive disorders such as ileus, jaundice and hydronephrosis. Epithelial-mesenchymal transition (EMT) is one of the major causes of tissue fibrosis and transforming growth factor β (TGF-β) has a pivotal function in the progression of EMT. Protein-bound polysaccharide K (PSK) is a biological response modifier that can modulate the TGF-β/Smad signaling pathway in vitro. In the present study, we established a fibrotic tumor model using human peritoneal mesothelial cells (HPMCs) and a human gastric cancer cell line to evaluate whether PSK attenuates tumor fibrosis. HPMCs exposed to PSK did not undergo the morphological change from a cobblestone-like pattern to a spindle-shape pattern normally induced by treatment with TGF-β. Immunofluorescence further demonstrated that PSK suppressed TGF-β-induced overexpression of α-SMA in the HPMCs. We further showed that HPMCs contributed to the proliferation of tumor fibrosis by using a mouse xenograft model. Additionally, PSK treatment of these mice significantly reduced the area of observable tumor fibrosis. These results suggest that seeded cancer cells transformed HPMCs into myofibroblast-like cells through their release of TGF-β in the microenvironment, facilitating the development of fibrous tumors in organs covered with HPMCs. Therefore, our study indicates that PSK has potential utility as an anti-fibrotic agent in the treatment of gastric cancer patients with PC.

A novel long non-coding RNA ENST00000480739 suppresses tumour cell invasion by regulating OS-9 and HIF-1α in pancreatic ductal adenocarcinoma

BACKGROUND

Invasion and metastasis are the distinct biologic characteristics of cancer, resulting in an exceptionally low 5-year survival rate in pancreatic ductal adenocarcinoma (PDAC). Understanding in detail the mechanisms underlying PDAC metastasis is critical for prevention and effective interventions. Long non-coding RNAs (lncRNAs) have been documented as having a critical role in cancer development and progression.

METHODS

We examined the expression levels of lncRNA ENST00000480739 and osteosarcoma amplified-9 (OS-9) mRNA in a cohort of 35 PDAC patients. Cell proliferation, invasion and migration were examined with and without ENST00000480739 overexpression in PDAC cells.

RESULTS

We determined that the ENST00000480739 expression level was remarkably decreased in tumorous tissues compared with their corresponding non-tumorous tissues. The expression of ENST00000480739 was negatively associated with tumour node metastasis stage and lymph node metastasis. In addition, ENST0000048073 was an independent prognostic factor of survival time in PDAC patients following surgery. Besides, enforced expression of ENST00000480739 suppressed PDAC cells' invasion in vitro. Overexpression of ENST00000480739 significantly increased both mRNA and protein levels of OS-9, and the luciferase assays confirmed that ENST00000480739 positively regulates OS-9 by activating the transcription level of the OS-9 promoter. We further found that ENST00000480739 may target hypoxia-inducible factor-1α (HIF-1α) expression by upregulating OS-9.

CONCLUSIONS

These findings suggest that the frequently downregulated ENST00000480739 in PDAC contributes to tumour metastasis and progression by regulating HIF-1α. Long non-coding RNA ENST00000480739 may provide not only a therapeutic potential to suppress metastasis but it may also be a novel biomarker for risk prognostication and personal therapy screening of PDAC patients.

Reoxygenation from chronic hypoxia promotes metastatic processes in pancreatic cancer through the Hedgehog signaling

Pancreatic ductal adenocarcinoma (PDAC) is among the most deadly types of malignancies because of its high ability to metastasize. PDAC is thought to be under hypoxic condition. Therefore, to investigate the mechanism of metastatic processes, chronic-hypoxia-resistant PDAC cells were newly generated under hypoxic condition for 3–6 months and reoxygenation experiments were performed using these chronic-hypoxia-resistant PDAC cells in in vivo-mimicking conditions. Proliferation, invasiveness and tumorigenicity in PDAC cells were significantly increased by reoxygenation. A Hedgehog (Hh) signaling component, Gli1, was significantly increased by reoxygenation. Gli1 knockdown inhibited reoxygenation-induced increases in proliferation and tumorigenicity and decreased invasiveness through suppression of matrix metalloproteinase (MMP) 2 and MMP9. Moreover, inhibition of Sonic Hh and Smoothened abrogated reoxygenation induced increases in proliferation and invasiveness. These results suggest that metastatic processes in PDAC are induced through activation of the Hh signaling pathway. Therefore, the Hh signaling pathway may be a therapeutic target for refractory PDAC in metastatic processes induced by reoxygenation.

Maturation of morphology, phenotype and functions of murine bone marrow-derived dendritic cells (DCs) induced by polysaccharide Kureha (PSK)

The aim of this work was to evaluate the influence of protein-bound polysaccharide Kureha(PSK) on murine dendritic cells (DCs). These impacts of PSK on DCs from bone marrow derived DCs(BMDCs) were assessed with inverted phase contrast microscope, conventional scanning electron microscopy (SEM), transmission electron microscopy (TEM) for morphology, fluorescence activated cell sorting (FACS) analysis, cytochemistry assay for key surface molecules, FITC-dextran for phagocytosis, bio-assay and enzyme linked immunosorbent assay (ELISA) for cytokine production. We found that under the influence of PSK, immature DCs changed into mature DCs with decrease of antigens up-taking, simultaneously high expression of key surface molecules of the MHC classII,CD40, CD80, CD86 and CD83 as well as more production of IL-12p70 and tumor necrosis factor α (TNF-α). These data indicate that PSK could markedly promote maturation of DCs and this adjuvant-like activity may have potential therapeutic value in vaccine preparation.

Correlation between efficacy of PSK postoperative adjuvant immunochemotherapy for gastric cancer and expression of MHC class I

Protein-bound polysaccharide K (PSK) is a glycoprotein that is purified from the mushroom Coriolus versicolor. In Japan, PSK is clinically used in combination with anticancer agents following gastric cancer surgery. Evaluation of the response is difficult, as efficacy is determined via antitumor immunoenhancing effects, and for that reason PSK has not become a standard therapy. The present study evaluated the expression of MHC class I in gastric cancer patients who received PSK postoperative adjuvant immunochemotherapy, and investigated the correlation between MHC class I expression and clinical outcomes. The subjects comprised 349 patients with stage II/III gastric cancer, who had received adjuvant therapy following curative resection between 1995 and 2008. MHC class I expression in the primary lesion was evaluated by immunohistochemical staining. Patients were divided into two treatment groups: one was only administered oral chemotherapy (chemotherapy-only group) and the other was administered chemotherapy plus PSK (PSK group). The clinical outcomes were compared between the two groups. The two groups did not differ in regard to their MHC class I expression. Expression-negative cases demonstrated 3-year recurrence-free survival (RFS) rates of 65% in the PSK group and 47% in the chemotherapy-only group. Therefore, the PSK group revealed a prolonged survival. For the 82 expression-negative cases with pN2 or greater, the RFS rates were 68% in the PSK group and 28% in the chemotherapy-only group, representing a significant difference. Thus, PSK adjuvant immunochemotherapy may be effective in MHC class I-negative patients, who are in a state of antitumor immunological tolerance, and patients with advanced lymph node metastasis of pN2 or greater.

Biological mechanism and clinical effect of protein-bound polysaccharide K (KRESTIN(®)): review of development and future perspectives

The mechanism of action of protein-bound polysaccharide K (PSK; KRESTIN(®)) involves the following actions: (1) recovery from immunosuppression induced by humoral factors such as transforming growth factor (TGF)-β or as a result of surgery and chemotherapy; (2) activation of antitumor immune responses including maturation of dendritic cells, correction of Th1/Th2 imbalance, and promotion of interleukin-15 production by monocytes; and (3) enhancement of the antitumor effect of chemotherapy by induction of apoptosis and inhibition of metastasis through direct actions on tumor cells. The clinical effectiveness of PSK has been demonstrated for various cancers. In patients with gastric or colorectal cancer, combined use of PSK with postoperative adjuvant chemotherapy prolongs survival, and this effect has been confirmed in multiple meta-analyses. For small-cell lung carcinoma, PSK in conjunction with chemotherapy prolongs the remission period. In addition, PSK has been shown to be effective against various other cancers, reduce the adverse effects of chemotherapy, and improve quality of life. Future studies should examine the effects of PSK under different host immune conditions and tumor properties, elucidate the mechanism of action exhibited in each situation, and identify biomarkers.

A review of the anti-tumor effect of the combined administration of a cyclooxygenase-2 selective inhibitor and a non-specific immunostimulant protein-bound polysaccharide on an advanced colon cancer model using colon cancer cell lines

The anti-tumor effect of a cyclooxygenase (COX)-2 selective inhibitor or a non-specific immunostimulant (PSK) alone, as well as the anti-tumor effect of their combined administration were examined on a hepatic metastasis model of colon cancer using a colon 26 cell line (CT26) and its highly metastatic variant. Anti-tumor effects were assessed by the number of hepatic metastases. Serum MMP-9, TGF-β and IL-6 were also measured. In a preliminary experiment, cells (5×10(5)) of a mouse colon cancer 26 cell line (CT26) and its highly metastatic variant were implanted below the splenic capsule in BALB/c and CDF1 mice. The number of hepatic metastatic CT26 cell lesions in the CDF1 mice of the non-spleen-removed group at 2 weeks was found to be optimum for the experiments. Although no significant difference was found, etodolac treatment showed the highest inhibitory effect on the number of hepatic metastases at a concentration of 30 mg/kg. In contrast, intraperitoneal administration of 50 mg/kg PSK showed an inhibitory effect on hepatic metastases, but a significant difference was not observed. PSK (p=0.002) or the combined use of etodolac and PSK (p=0.001) exhibited a significant inhibition of the number of hepatic metastases. In addition, MMP-9 was significantly inhibited by the single use of etodolac or PSK, and was inhibited with an additive effect by the combined use of etodolac and PSK. IL-6 and TGF-β were significantly inhibited following the combined use of etodolac and PSK. In conclusion, etodolac did not exhibit any significant hepatic metastasis inhibitory effect, whereas it significantly reduced the MMP-9 level. PSK reduced both the number of hepatic metastases and MMP-9. Combined use of etodolac and PSK did not show any additive effect in the inhibition of the number of hepatic metastases, whereas it inhibited MMP-9, TGF-β and IL-6, suggesting the benefit of a combined effect.

Utility of hyaluronan oligomers and transforming growth factor-beta1 factors for elastic matrix regeneration by aneurysmal rat aortic smooth muscle cells

The progression of aortic aneurysms (AAs) is typically associated with an activated smooth muscle cell (SMC) phenotype, diminished density of mature medial elastic fibers, and an elevated presence of matrix-degrading enzymes, which ultimately leads to vessel rupture. Currently, no surgical or nonsurgical methods are available to regress aneurysms via regeneration of new elastic matrices, particularly because of inherently poor elastin synthesis by adult vascular cells and absence of tools to stimulate the same. We seek to address this void in this study. We recently showed 0.2 microg/mL of hyaluronan oligomers and 1 ng/mL of transforming growth factor-beta1 (termed elastogenic factors) to dramatically enhance elastin synthesis and matrix formation by healthy aortic SMCs. In this study, the effect of these factors, alone or together, on suppressing procalcific and elastolytic activities of aneurysmal vascular cells, and improving their elastin matrix synthesis and assembly is examined. Periadventitial injury with calcium chloride was used to induce AAs in rats, and approximately 45% increase in aortic diameter was observed after 4 weeks. Aneurysmal SMCs isolated from these AA segments produced higher levels of inflammatory markers matrix metalloproteinases-2 and 9 elastase activity and calcific deposits, while synthesizing significantly less collagen, tropoelastin, and matrix elastin proteins over a 3-week culture period, relative to healthy SMCs. While hyaluronan oligomers alone significantly suppressed aneurysmal cell proliferation and promoted 20-50% increases in collagen and elastin synthesis (p < 0.01), transforming growth factor-beta1 alone had no effect on cellular proliferation and elastin synthesis. However, provision of factors together resulted in significantly higher amounts of collagen/elastin protein synthesis and crosslinking, by upregulating lysyl oxidase and desmosine. Compared to their individual contributions, the factors together were highly effective in minimizing the release of inflammatory enzymes, and encouraging elastic fiber formation. Since elastic matrix amounts were one order of magnitude lower than that observed with healthy cells, even upon elastogenic stimulation at doses optimized previously for healthy cells, increased doses are likely required and must be reoptimized for diseased cells. Despite this, the results point to the potential utility of these elastogenic factors in regenerating elastic matrices within AAs.

Transforming growth factor beta 1 and hyaluronan oligomers synergistically enhance elastin matrix regeneration by vascular smooth muscle cells

Elastin is a vital structural and regulatory matrix protein that plays an important role in conferring elasticity to blood vessel wall. Previous tissue engineering approaches to regenerate elastin in situ or within tissue engineering constructs are curtailed by innate poor elastin synthesis potential by adult vascular smooth muscle cells (SMCs). Currently, we seek to develop cellular cues to enhance tropoelastin synthesis and improve elastin matrix yield, stability, and ultrastructure. Our earlier studies attest to the elastogenic utility of hyaluronan (HA)-based cellular cues, though their effects are fragment size dependent and dose dependent, with HA oligomers deemed most elastogenic. We presently show transforming growth factor beta 1 (TGF-beta1) and HA oligomers, when provided concurrently, to synergistically and dramatically improve elastin matrix regeneration by adult vascular SMCs. Together, these cues suppress SMC proliferation, enhance synthesis of tropoelastin (8-fold) and matrix elastin protein (5.5-fold), and also improve matrix elastin yield (45% of total elastin vs. 10% for nonadditive controls), possibly by more efficient recruitment of tropoelastin for crosslinking. The density of desmosine crosslinks within the elastin matrix was itself attenuated, although the cues together modestly increased production and activity of the elastin crosslinking enzyme, lysyl oxidase. TGF-beta1 and HA oligomers together induced much greater assembly of mature elastin fibers than they did separately, and did not induce matrix calcification. The present outcomes might be great utility to therapeutic regeneration of elastin matrix networks in situ within elastin-compromised vessels, and within tissue-engineered vascular graft replacements.

Changes of histology and expression of MMP-2 and nm23-H1 in primary and metastatic gastric cancer

AIM: To investigate the changes of histology and expression of MMP-2 and nm23-H1 in primary and metastatic gastric cancer.

METHODS: One hundred and seventy-seven gastric cancer patients with lymph node and/or distal metastasis between 1997 and 2001 were reviewed. Differences in histology of the primary and metastatic gastric cancer were assessed. MMP-2 and nm23-H1 immunoreactivity was compared in 44 patients with tumor infiltration to the serosa layer.

RESULTS: Poorly and moderately differentiated metastatic gastric cancer was found in 88.7% (157/177) and primary gastric cancer in 75.7% (134/177) of the patients. The histological type of metastatic gastric cancer that was not completely in accordance with the preponderant histology of primary gastric cancer was observed in 25 patients (14.1%). MMP-2 immunoreactivity in metastatic gastric cancer was significantly stronger than that in primary gastric cancer, while nm23-H1 immunoreactivity showed no difference in primary and metastatic gastric cancer.

CONCLUSION: Metastatic gastric cancer presents more aggressive histological morphology and higher MMP-2 immunoreactivity than primary gastric cancer. This heterogeneity may elicit a possible mechanism of gastric cancer metastasis.

Relationship between matrix metalloproteinase-2 mRNA expression and clinicopathological and urokinase-type plasminogen activator system parameters and prognosis in human gastric cancer

AIM: To investigate the relationship between matrix metalloproteinase-2 (MMP-2) mRNA expression and clinicopathologic and urokinase-type plasminogen activator (uPA) system parameter and prognosis in human gastric cancer.

METHODS: Expression of MMP-2 mRNA, uPA, and uPA-R mRNA in tumor tissues and ≥5 cm adjacent normal tissues from 67 cases of gastric cancer was studied using RT-PCR and Northern blot respectively. Survival analyses were done using the Kaplan-Meier method.

RESULTS: The expression rates of MMP-2 mRNA, uPA and uPA-R mRNA in tumor tissues (31%, 41%, and 51%, respectively) were significantly higher than those in ≥5 cm adjacent tissues (19%, 11%, and 9%; χ² = 4.59, 43.58, and 53.24 respectively, P<0.05, 0.0001, and 0.0001, respectively). Expression of MMP-2 mRNA was significantly correlated with lymph node metastasis (metastasis: 61.9%, no metastasis: 39.1%, χ² = 7.61, P<0.05), Lauren’s classification of diffuse/mixed types: 54.2%, intestinal type: 26.3%, χ² = 4.25, P<0.05, expression of uPA and uPA-R mRNA (uPA+: 55.1%, uPA-: 22.2% and uPA-R+: 54.9%, uPA-R-: 18.8%, χ² = 5.72 and 6.40 respectively, P<0.05). Kaplan-Meier survival analysis of MMP-2 mRNA expression did not show significant difference in all 67 cases, but revealed an association of the expression of MMP-2 mRNA, uPA, and uPA-R mRNA with worse prognosis (P = 0.0083, 0.0160, and 0.0094, respectively).

CONCLUSION: MMP-2 may play an important role in the development of invasion and metastasis of gastric cancer.

Interleukin 1beta enhances invasive ability of gastric carcinoma through nuclear factor-kappaB activation

PURPOSE

We examined the role of interleukin (IL)-1beta in activation of nuclear factor kappaB (NF-kappaB) and the biological function of activated NF-kappaB in gastric carcinoma cells.

EXPERIMENTAL DESIGN

Human gastric carcinoma cell line GCTM-1 was used to examine NF-kappaB activation by immunostaining and electrophoretic mobility shift assay. Matrix metalloproteinase (MMP)-9 expression, which plays an important role in tumor invasion, was assessed by semiquantitative reverse transcription-PCR, Western blotting, and immunostaining. The invasive ability of GCTM-1 cells was measured by Matrigel invasion assay. In vivo expression of IL-1beta and MMP-9 and activation of NF-kappaB in 10 surgically resected gastric carcinoma specimens were examined immunohistochemically.

RESULTS

IL-1beta enhanced NF-kappaB activation, MMP-9 expression, and the invasive ability of GCTM-1. A NF-kappaB inhibitor, pyrrolidine dithiocarbamate, suppressed both MMP-9 expression and invasiveness of IL-1beta-treated GCTM-1 cells. IL-1beta did not increase the invasive ability of GCTM-1 cells transfected with MMP-9 antisense oligonucleotide. Concomitant expression of IL-1beta and nuclear NF-kappaB was observed in 3 of 10 gastric carcinoma specimens. Cells producing IL-1beta were tumor-infiltrating macrophages in two specimens and gastric carcinoma cells in one specimen.

CONCLUSIONS

One of the molecules that may play a role in NF-kappaB activation in some gastric carcinomas is IL-1beta. The present results suggest that IL-1beta increases the invasive ability of carcinoma cells through activation of NF-kappaB and the resulting MMP-9 expression.

Adjuvant immunochemotherapy with oral Tegafur/Uracil plus PSK in patients with stage II or III colorectal cancer: a randomised controlled study

Intravenous fluorouracil and leucovorin is the standard adjuvant treatment for stage III colon cancer. However, oral adjuvant chemotherapy is attractive because it has low toxicity and greater convenience. We investigated the benefits of oral protein-bound polysaccharide K (PSK) with tegafur/uracil (UFT) as an adjuvant in stage II and III colorectal cancer. Patients were assigned to groups that received either 3 g PSK plus 300 mg UFT, or 300 mg UFT alone orally each day for a 2-year period following intravenous mitomycin C. Of 207 registered patients, 205 with stage II (n=123) or III (n=82) were analysed. The 5-year disease-free survival was 73.0% (95% CI 65.6-80.4%) with PSK (n=137) and 58.8% (95% CI 47.1-70.5%) in the controls (n=68) (P=0.016). Polysaccharide K reduced the recurrence by 43.6% (95% CI 4.5-66.7%) and mortality by 40.2% (95% CI -12.5 to 68.3%). The 5-year survival was 81.8% (95% CI 75.3-88.2%) in the PSK group and 72.1% (95% CI 61.4-82.7%) in the control group (P=0.056). In stage III patients, disease-free and overall survivals in patients receiving PSK were increased significantly: 60.0% (95% CI 47.1-72.9%) and 74.6% (95% CI 63.0-86.1%) in the PSK group as compared with 32.1% (95% CI 14.8-49.4%) and 46.4% (95% CI 28.0-64.9%) in the controls (P=0.002 and 0.003, respectively). Polysaccharide K prevented recurrence, particularly lung metastases (P=0.02; odds ratio 0.27; 95% CI 0.09-0.77). In the models, the presence of regional metastases (relative risk, 2.973; 95% CI 1.712-5.165; P<0.001), omission of PSK (relative risk, 2.106; 95% CI 1.221-3.633; P=0.007), and higher primary tumour (relative risk, 4.398; 95% CI 1.017-19.014; P=0.047) were each significant indicators of recurrence. Adverse effects were mild and compliance was good. Oral PSK with UFT reduced recurrence in stage II and III colorectal cancer, and increased survival in stage III.

Complete Freund's adjuvant promotes the increases of IFN-gamma and nitric oxide in suppressing chronic arthritis induced by pristane

The aim of this study was to determine therapeutic effects of complete Freund's adjuvant (CFA) on the progression and relapsing of pristine-induced arthritis (PIA) and investigate the mechanism involved. Chronic relapsing arthritis was induced by pristine in LEW rats. After onset of arthritis, rats were intradermally injected CFA and rats in control group were injected the same volume of PBS. Arthritis was monitored visually, and joint pathology was examined histologically. Cytokine mRNA expression in inguinal lymph nodes was assessed by RT-PCR. The levels of nitric oxide (NO) in serum were measured by colorimetric assay. The results showed that CFA significantly suppressed the progression and relapsing of PIA. Relapsing rate of PIA in CFA-treated group was 12.5% and it was 85.7% in PBS-control group (P < 0.005). CFA markedly inhibited the infiltration of inflammatory cells and cartilage damage in the joints of CFA-treated rats and promoted the increases of IFN-y mRNA and NO levels. The present study provided an implication that adjuvant therapy may be a new strategy for the treatments of rheumatoid arthritis (RA) and other chronic inflammatory diseases.

Experimental study of anti-tumor effects of polysaccharides from Angelica sinensis

AIM: To investigate the in vivo anti-tumor effects of total polysaccharide (AP-0) isolated from Angelica sinensis (Oliv.) Diels (Danggui) on mice and the in vitro inhibitory effects of AP-0 and its sub-constituents (AP-1, AP-2 and AP-3) on invasion and metastasis of human hepatocellular carcinoma.

METHODS: Three kinds of murine tumor models in vivo, sarcoma 180 (S180), leukemia L1210 and Ehrlich ascitic cancer (EAC) were employed to investigate the anti-tumor effects of AP-0. For each kind of tumor model, three experimental groups were respectively given AP-0 at doses of 30, 100 and 300 mg/kg by ip once a day for 10 days. Positive control groups were respectively given Cy at a dose of 30 mg/kg for S180 and leukemia L1210, and 5-FU at a dose of 20 mg/kg for EAC. On d 11, mice bearing S180 were sacrificed and the masses of tumors, spleens and thymus were weighed. The average living days of mice bearing EAC and of mice bearing L1210 were observed, and the rates of life prolongation of each treatment were calculated, respectively. The inhibitory effects of APs on hepatoma invasion and metastasis in vitro were investigated by employing human hepatocellular carcinoma cell line (HHCC) with the Matrigel invasion chamber, adhesion to extracelluler matrix and chemotatic migration tests, respectively.

RESULTS: AP-0 had no obviously inhibitory effect on the growth of S180, but it could significantly decrease the thymus weights of the mice bearing S180. AP-0 could significantly reduce the production of ascitic liquids and prolong the life of mice bearing EAC. AP-0 could also increase the survival time of mice bearing L1210. AP-0 and AP-2 had significantly inhibitory effects on the invasion of HHCC into the Matrigel reconstituted basement membrane with the inhibitory rates of 56.4% and 68.3%, respectively. AP-0, AP-1, AP-2 and AP-3 could influence the adhesion of HHCC to extracellular matrix proteins (Matrigel and fibronectin) at different degrees, among them only AP-3 had significant blocking effect on the adhesion of HHCC to fibronectin with an inhibitory rate of 30.3%. AP-0, AP-1 and AP-3 could partially inhibit the chemotactic migration abilities of HHCC.

CONCLUSION: The experimental findings suggest that total polysaccharide of Angelica sinensis (Oliv.) Diels (Chinese Danggui) possesses anti-tumor effects on experimental tumor models in vivo and inhibitory effects on invasion and metastasis of hepatocellular carcinoma cells in vitro.

PSK-mediated NF-kappaB inhibition augments docetaxel-induced apoptosis in human pancreatic cancer cells NOR-P1

Docetaxel, a member of the taxane family, has been shown to induce apoptosis in a variety of cancer cells. However, toxicity at therapeutic doses has precluded the use of docetaxel alone for the management of cancer patients. PSK, a protein-bound polysaccharide, is widely used in Japan as an immunopotentiating biological response modifier for cancer patients. Our previous study showed that PSK induced downregulation of several invasion-related factors, suggesting an interaction of PSK with transcriptional factors. In this study, we showed that PSK dose dependently enhanced apoptosis induced by 1 nM of docetaxel in a human pancreatic cancer cell line NOR-P1. Furthermore, PSK inhibited docetaxel-induced nuclear factor kappa B (NF-kappaB) activation. Moreover, the expression of cellular inhibitor of apoptosis protein (cIAP-1), which is transcriptionally regulated by NF-kappaB and functions as an antiapoptotic molecule through interrupting the caspase pathway, was also inhibited by treatment with PSK plus docetaxel. As a result, PSK enhanced the docetaxel-induced caspase-3 activation. In addition, treatment by transfection of NF-kappaB decoy oligodeoxynucleotides (ODNs), but not scramble ones, inhibited the expression of cIAP-1 in NOR-P1 cells and induced a significant increase in docetaxel-induced apoptosis. Our data indicate that PSK suppresses the docetaxel-induced NF-kappaB activation pathway. Combination of PSK with a low dose of docetaxel may be a new therapeutic strategy to treat patients with pancreatic cancer.