We examined the effect of PSK, a protein-bound polysaccharide, upon in vivo metastasis and in vitro invasion of the B16-BL6 mouse melanoma cells. (1) PSK suppressed in vivo artificial and spontaneous lung metastases of B16-BL6 in C57BL/6 mice. (2) PSK in a dose-dependent fashion suppressed in vitro invasion and chemotaxis of the tumor cells using filters coated with a reconstituted basement membrane. (3) PSK had little effect on DNA synthesis in tumor cells in vitro, but suppressed tumor cell adhesion to, degradation of, and haptotaxis to components of the basement membrane. (4) PSK suppressed the binding of tumor cells to components of the basement membrane. These findings suggest that PSK may suppress metastasis through inhibition of tumor cell invasion and that this effect is the result of interactions between PSK and components of the basement membrane.
The anticancer effects of PSP purified products, PSP-A, PSP-B, PSP-C and crude product PSP-Cr and KS-2 were compared on four human tumor cell lines in vitro. It was found that the inhibition rate of cell proliferation of PSP-A was higher than that of PSP-Cr, PSP-B and PSP-C (P<0.05). On SPC cells, the inhibition rate of PSP-A at a dosage of 1000ug/ml was 62.7%, being the highest as compared with those on the other three cell lines.
The effect of the inhibition of KS-2 on Mei tumorous cells is obvious. Its inhibition rate is 62.5%.
Morphological changes were seen in all the four cell lines, especially in SPC cells after PSP-A treatment.
The immunomodulating action of two mushroom antitumor polysaccharides, polysaccharide-protein complex (PSPC) and lentinan, was elucidated through analysing the expression profile of cytokines during a time course (0 h to 48 h) after their administration. Among the 5 cytokine genes, the induction of a marked increase in the mRNA levels of IL-la, IL-lp, TNF-a, IFN-)I and M-CSF by PSPC and lentinan was observed in the peritoneal exudate cells and splenocytes. However, the time point of their increased production was different after PSPC and lentinan administration.
To evaluate the efficacy of PSK for adjuvant immuno-chemotherapy in patients who had undergone radical gastrectomy, a randomized controlled trial has been in progress in collaboration with 46 institutions in the Chubu district of Japan. A total of 262 patients were registered for this trial during the two years from July 1985 to June 1987 with a centralized registration system, and were allocated into the 5-FU+PSK group (Group P) and 5-FU alone group (Group C) by the minimization method following the random permuted blocks method. Between the two groups, the parameters of sex, age, serosal invasion (S), lymph-node metastasis (N), and the combination of S . N factor levels were distributed without significant differences. An induction treatment with MMC 6 mg/m2 was given to all patients following curative mastectomy and on the 7th post-operative day. Two weeks after surgery, Group P received alternately PSK 3 g/day for 4 week and 5-FU 150 mg/day for 4 weeks as one course, and 10 courses were given. Group C received 5-FU alone for 4 weeks using alternate rest interval for 4 weeks. Since both experimental and clinical studies suggested that alternate treatments using PSK and anticancer agents were effective, treatment in this trial alternated PSK and 5-FU. A final follow-up study will be completed in June 1992, when all patients shall have survived more than 5 years after surgery. The administration of 5-FU was completed by January. 1989, but PSK has been administered to group P. The period from 18 to 42 months after surgery was reached in all eligible patients (253) at the end of December 1988. The disease-free survival curves and overall survival curves of group P were significantly (p = 0.018 and p = 0.045,) better than those of group C.
A total of 103 patients with advanced gastric carcinoma were randomized after curative surgery to receive an alternate administration of carabzilquinone (CQ) and PSK (Krestin) or carbazilquinone alone. Each course of therapies started 1 week after the surgical operation and therapy schedules consisted of 9 courses. In each course of 6 weeks, CQ was administered on day 0, 8, and 15. In combined immunochemotherapy group, PSK was given orally in 3-divided doses of 2g/m^2/day from the day of the third CQ administration for consecutive 4 weeks. Estimated survival rate and cumulative survival curve were compared untilizing the data up to 7 years after the operation. There was no overall significant difference in survival rates between the CQ plus PSK group and the CQ alone group, but a group of patients survived significantly longer when treated with the combination of CQ and PSK. Neither in more advanced cases nor in cancers of early stages, the addition of PSK provided an additive effect. The favorable result obtained in one subgroup treated with PSK, suggests that the use of this agent in treating gastric cancers should be carefully evaluated in terms of serosal infiltration and nodal metastasis.?
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Department of Zoology, The University of Hong Kong, Hong Kong, SAR, P.R. China.
Proteins and peptide bound polysaccharides (PSP) extracted from Basidiomycetous fungi are widely used in cancer immunotherapy and recently demonstrated to induce apoptosis in cancer cells in vitro. In order to provide the molecular pharmacological mechanisms of PSP on human cancer cells, we investigated the gene expression profiles of PSP-treated apoptotic human promyelotic leukemic HL-60 cells using ResGen 40k IMAGE printed cDNA microarray. In total 378 and 111 transcripts were identified as differentially expressed in the apoptotic cells by at least a factor of 2 or 3, respectively. Our data show that PSP-induced apoptosis in HL-60 cells might be mediated by up-regulation of early transcription factors such as AP-1, EGR1, IER2 and IER5, and down-regulation of NF-kappaB transcription pathways. Other gene expression changes, including the increase of several apoptotic or anti-proliferation genes, such as GADD45A/B and TUSC2, and the decrease of a batch of phosphatase and kinase genes, may also provide further evidences in supporting the process of PSP induced apoptosis in cancer cells. Some of the well-characterized carcinogenesis-related gene transcripts such as SAT, DCT, Melan-A, uPA and cyclin E1 were also alternated by PSP in the HL-60 cells. These transcripts can be employed as markers for quality control of PSP products on functional levels. The present study provides new insight into the molecular mechanisms involved in PSP-induced apoptosis in leukemic HL-60 cells analyzed by cDNA microarray.
PMID: 16010435 [PubMed – indexed for MEDLINE]
Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, PR. China.
Breast cancer is the most common cancer among women worldwide. Discomfort and fatigue are usually arisen from anticancer therapy such as surgery, radiotherapy, chemotherapy, hormonal therapy, or combination therapy, because of the suppressed immunological functions. Yunzhi (Coriolus versicolor) can modulate various immunological functions in vitro, in vivo, and in human clinical trials. Danshen (Salvia miltiorrhiza) has been shown to benefit the circulatory system by its vasodilating and anti-dementia activity. The purpose of this clinical trial was to evaluate the immunomodulatory effects of Yunzhi-Danshen capsules in post-treatment breast cancer patients. Eighty-two patients with breast cancer were recruited to take Yunzhi [50 mg/kg body weight, 100% polysaccharopeptide (PSP)] and Danshen (20 mg/kg body weight) capsules every day for a total of 6 months. EDTA blood samples were collected every 2 months for the investigation of immunological functions. Flow cytometry was used to assess the percentages and absolute counts of human lymphocyte subsets in whole blood. Plasma level of soluble interleukin-2 receptor (sIL-2R) was measured by enzyme-linked immunosorbent assay (ELISA). Results showed that the absolute counts of T-helper lymphocytes (CD4+), the ratio of T-helper (CD4+)/T suppressor and cytotoxic lymphocytes (CD8+), and the percentage and the absolute counts of B-lymphocytes were significantly elevated in patients with breast cancer after taking Yunzhi-Danshen capsules, while plasma slL-2R concentration was significantly decreased (all p < 0.05). Therefore, the regular oral consumption of Yunzhi-Danshen capsules could be beneficial for promoting immunological function in post-treatment of breast cancer patients.
PMID: 16047556 [PubMed – indexed for MEDLINE]
Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Cancer prevention studies were conducted with VPS, a hot water extract of the Coriolus versicolor (CV) mushroom, in female Swiss mice. The extract was administered in the diet for life to the animals. Three groups of mice received the following treatments: a). 1,2-dimethylhydrazine dihydrochloride (1,2-DMH) was administered as 10 weekly subcutaneous injections of 20 microg/g body weight, starting at 9 weeks of age; b). VPS was given at a 2% dose level starting at 7 weeks of age followed by 1,2-DMH, as described in group a; c). 1,2-DMH was administered as described in group a followed by VPS at a 2% dose level starting at 21 weeks of age. The number of animals with large intestinal tumors and the total number of these tumors were: a). 30,321; b). 29,359; and c). 28,415. These differences are not statistically significant. Because extracts of the CV mushroom are used by cancer patients as nutritional supplements in the U.S., and particularly in the Orient, the present negative result should caution its users.
PMID: 16097440 [PubMed – indexed for MEDLINE]
School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, PR China. email@example.com
Six fungal elicitors prepared from Rhodotorula rubra, Rhodotorula glutinis, Panus conchatus, Coriolus versicolor, Mucor mucedo, Mortieralla alpina M-23 were examined to determine their effects on the growth, total carotenoids and astaxanthin formation by Xanthophyllomyces dendrorhous. The results showed that different fungal elicitor could cause diversely stimulating effects. Among the fungal elicitors tested, the M. mucedo elicitor concentration of 30 mg l(-1) promoted the biomass and total carotenoids yield most remarkably, resulting in 69.81+/-6.00% and 78.87+/-4.15% higher than the control, respectively. At the concentration of 30 mg l(-1), R. glutinis elicitor stimulated the highest astaxanthin yield with a 90.60+/-5.98% increase compared to the control. The R. rubra elicitor concentration of 30 mg l(-1) resulted in the optimal total carotenoids and astaxanthin content to be 42.24+/-0.49% and 69.02+/-0.72% higher than the control, respectively. At the concentration of 30 mg l(-1), R. rubra elicitor gave the highest increase in the ratio of astaxanthin in total carotenoids by 18.85+/-0.11% of the control.
PMID: 16154499 [PubMed – indexed for MEDLINE]