A randomized controlled study was carried out on curatively resected gastric cancer patients in a cooperative study involving 16 institutions in order to evaluate the effect of an alternative long-term adjuvant immunochemotherapy using Esquinon (CQ) and Krestin (PSK). One week after surgery, CQ was given at a dose of 2mg/m2 once a week for 3 weeks and this was repeated every 6 weeks. CQ was administered intravenously in the 1st course and thereafter orally up to 9 courses. Three postoperative week, immunotherapy was then started in which PSK was given orally in 3 divided doses of
2g/m2/day from the day when CQ therapy ended for 4 consecutive weeks, and this performed for every course. Estimated survival rate and cumulative survival curves were compared utilizing the data up to 7 years after surgery in the chemotherapy group given CQ alone and in the immunochemotherapy group given CQ + PSK. The survival curve in all cases showed a favorable form in the CQ + PSK group for up to 36 months, and thereafter it crossed with that of the CQ group for up to 68 months. Both curves twisted at 68 months and then deviated from each other, showing that the effect in the CQ + PSK group beneficial. The curve showed a twisting configuration throughout the treatment period. There was no statistically significant difference between the survival curves of the two groups. Retrospective survival analysis was then performed on separate subgroups classified into the category of S1, S2, N1, and N2. The CQ + PSK group was better than the CQ alone group in its survival rate for the S1 + S2 (N1-2) group, the percentage being 11.5%, and a statistically significant difference was observed between the two groups (p = 0.089).
The most effective treatment for gastric cancer is complete surgical resection with lymphadenectomy. However, a number of patients experience recurrence of the cancer even after curative surgery. This review focuses on comparative trials studying the use of adjuvant therapy with chemotherapy plus immunotherapy in the treatment of patients with curatively resected gastric cancer. Preoperative and intraperitoneal therapy, and therapy for advanced or recurrent gastric cancer are also discussed. At present, some subset analyses of adjuvant trials have shown favorable results suggesting that the biological response modifiers (BRMs), PSK or OK-432, add a benefit to chemotherapy. For advanced gastric cancer, although gastric cancer cells are generally not very sensitive to most of the currently available chemotherapeutic agents, it has been reported that biochemical modulation with treatments including low-dose cisplatin + 5-FU (fluorouracil) have high response rates and exert an immunomodulatory effect especially when used in combination with BRMs. The impact of splenectomy and some of the
promising newly developed drugs are discussed.
Up to now, the three main weapons against cancer have been surgery, radiotherapy and chemotherapy. Although these classical methods of treatment have given fairly good results in general, the results have yet to be improved, especially in late cases. Thus for many years, the search for a more effective means of anti-cancer treatment has been going on world-wide. An ideal drug would of course be one that could directly kill all the cancer cells without harming the normal tissues, and also without causing general toxicity. However, at present a more practical approach is to use drugs that would either enhance the biological effects of radiation or of cytotoxic agents, or strengthen the organism’s immunological defenses. In recent years, several such drugs have been undergoing clinical trials, for example, Misonidazole, RS 2508, OK-432, PSK, etc.
School of Pharmacy, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
Abstract
Coriolus versicolor (CV), also called Yunzhi, has been demonstrated to exert anti-tumor effects on various types of cancer cells, but the underlying mechanism has not been fully elucidated. The present study aimed to evaluate the in vitro anti-tumor activity of a standardized aqueous ethanol extract prepared from CV on four breast cancer cell lines using MTT assay, and test whether the mechanism involves apoptosis induction and modulation of p53 and Bcl-2 protein expressions using cell death detection ELISA, p53 and Bcl-2 ELISAs respectively. Our results demonstrated that the CV extract dose-dependently suppressed the proliferation of three breast tumor cell lines, with ascending order of IC50 values: T-47D, MCF-7, MDA-MB-231, while BT-20 cells were not significantly affected. Tumoricidal activity of the CV extract was found to be comparable to a chemotherapeutic anti-cancer drug, mitomycin C. Nucleosome productions in apoptotic MDA-MB-231, MCF-7 and T-47D cells were significantly augmented in a time-dependent manner and paralleled the anti-proliferative activity of CV extract. Expression of p53 protein was significantly upregulated only in T-47D cells treated with the CV extract in a dose- and time-dependent fashion, but not in MCF-7 (except at 400 mug/ml after 16 h) and MDA-MB-231 cells. The CV extract significantly induced a dose-dependent downregulation of Bcl-2 protein expression in MCF-7 and T-47D cells, but not in MDA-MB-231 cells. These results suggested that apoptosis induction, differentially dependent of p53 and Bcl-2 expressions, might be the possible mechanism of CV extract-mediated cytotoxicity in human breast cancer cells in vitro.
PMID: 15908782 [PubMed – indexed for MEDLINE]Free Article
Department of Zoology, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, P.R. China.
Abstract
Activation of the cell death program (apoptosis) is a strategy for the treatment of human cancer, and unfortunately a large number of drugs identified as cell cycle-specific agents for killing cancer cells are also toxic to normal cells. The present study demonstrates that the polysaccharide peptide (PSP) extracted from the Chinese medicinal mushroom, Coriolus versicolor, used in combination therapy in China, has the ability to lower the cytotoxicity of certain anti-leukemic drugs via their interaction with cell cycle-dependent and apoptotic pathways. Flow cytometry analysis demonstrated that pre-treatment of PSP (25-100 microg/ml) dose-dependently enhanced the cell cycle perturbation and apoptotic activity of doxorubicin (Doxo) and etoposide (VP-16), but not cytarabine (Ara-C) in human promyelocytic leukemia HL-60 cells. The antagonistic result from combined treatment with Ara-C and PSP may be caused by the removal of HL-60 cells in the G1-S boundary by PSP before exposure to Ara-C. A negative correlation between the increase in apoptotic cell population (pre-G1 peak) with the S-phase cell population expression (R2=0.998), the expression of cyclin E expression (R2=0.872) and caspase 3 activity (R2=0.997) suggests that PSP enhanced the apoptotic machinery of Doxo and VP-16 in a cell cycle-dependent manner and is mediated, at least in part, by the PSP-mediated modulation of the regulatory checkpoint cyclin E and caspase 3. This study is the first to describe the cell cycle mechanistic action of PSP and its interaction with other anticancer agents. Our data support the potential development of PSP as an adjuvant for leukemia treatment, but also imply the importance of understanding its interaction with individual anticancer agents.
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.
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.?
Department of Zoology, The University of Hong Kong, Hong Kong, SAR, P.R. China.
Abstract
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.
Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, PR. China.
Abstract
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.
Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Abstract
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.