Specific medicinal plant polysaccharides effectively enhance the potency of a DC-based vaccine against mouse mammary tumor metastasis.

Dendritic cell (DC) vaccines are a newly emerging immunotherapeutic approach for the treatment and prevention of cancer, but major challenges still remain particularly with respect to clinical efficacy. Engineering and optimization of adjuvant formulations for DC-based vaccines is one strategy through which more efficacious treatments may be obtained. In this study, we developed a new ex vivo approach for DC vaccine preparation. We evaluated two highly purified mixed polysaccharide fractions from the root of Astragalus membranaceus and Codonopsis pilosulae, named Am and Cp, for their use in enhancing the efficiency of a DC-based cancer vaccine against metastasis of 4T1 mammary carcinoma in mice. Mixed lymphocyte reaction showed all Am-, Cp- and [Am+Cp]-treated DCs enhanced mouse CD4+ and CD8+ T-cell proliferation. [Am+Cp]-treated DCs exhibited the strongest anti-4T1 metastasis activity in test mice. Treatments with Am, Cp and [Am+Cp] also resulted in augmented expression of CD40, CD80 and CD86 markers in test DCs. Bioinformatics analysis of the cytokine array data from treated DCs identified that [Am+Cp] is efficacious in activation of specific immune functions via mediating the expression of cytokines/chemokines involved in the recruitment and differentiation of defined immune cells. Biochemical analysis revealed that Am and Cp are composed mainly of polysaccharides containing a high level (70-95%) glucose residues, but few or no (< 1%) mannose residues. In summary, our findings suggest that the specific plant polysaccharides Am and Cp extracted from traditional Chinese medicines can be effectively used instead of bacterial LPS as a potent adjuvant in the formulation of a DC-based vaccine for cancer immunotherapies.

Evaluation of the therapeutic efficacy of sequential therapy involving percutaneous microwave ablation in combination with 131I-hypericin using the VX2 rabbit breast solid tumor model.

PURPOSE: Combination of percutaneous microwave ablation (PMWA) and intravenous injection of 131I-hypericin(IIIH) may bear potential as a mini-invasive treatment for tumor. The objective of this study was to assess the effect of PMWA and IIIH in breast tumor growth. METHODS: Ten New Zealand White rabbits bearing VX2 breast carcinomas were randomly divided into two groups (each 5 examples) and processed using PMWA followed by IIIH and IIIH alone. The IIIH activity was evaluated using planar scintigraphy, autoradiography and biodistribution analysis. The maximum effective safe dose of IIIH was found through 48 rabbits with VX2 breast tumor, which were randomized into six groups (n=8 per group). Subsequently, a further 75 rabbits bearing VX2 breast solid tumors were randomly divided into five groups (each 15 examples) and treated as follows: A, no treatment group; B, PMWA alone; C, IIIH alone; D, PMWA+IIIH×1 (at 8 h post-PMWA); and E, PMWA+IIIH×2 (at 8 h and at 8 days post-PMWA). The therapeutic effect was assessed by measurement of tumor size and performation of positron emission tomography/computed tomograph (PET/CT) scans, liver and renal function tests and Kaplan-Meier survival analysis. RESULTS: The planar scintigraphy findings suggested a significant uptake of 131I in necrotic tumor tissue. The autoradiography gray scales indicated higher selective uptake of IIIH by necrotic tissue, with significant differences between the groups with and those without necrotic tumor tissue (P<0.05). The maximum effective safe dose of IIIH was 1 mCi/kg. The PET/CT scans and tumor size measurement suggested improvements in treatment groups at all time points (P<0.01). Significant differences were detected among Groups A, B, D and E (P<0.05). Lower levels of lung metastasis were detected in Groups D and E (P<0.05). There were no abnormalities in liver and renal functions tests or other reported side effects. CONCLUSION: IIIH exhibited selective uptake by necrotic tumor tissue. Sequential therapy involving PMWA+IIIH was successfully inhibiting tumor growth and prolonging survival.

Effects of flaxseed lignan and oil on bone health of breast-tumor-bearing mice treated with or without tamoxifen.

Previous studies showed that flaxseed lignan (secoisolariciresinol diglucoside, SDG) and oil (FO) inhibit established breast tumor growth in athymic mice with or without tamoxifen (TAM) treatment. TAM was found to increase bone mineral content (BMC) and density (BMD) in breast cancer patients. It is not known whether SDG or FO alone or combined with TAM affects bone health. Hence, the effects of SDG and FO, alone or in combination, on BMC, BMD, and biomechanical bone strength in ovariectomized athymic mice with established human breast tumors (MCF-7) treated with or without TAM were studied. In a factorial design, mice were divided into four non-TAM and four TAM groups. Each group consisted of mice fed a basal diet (BD), SDG (1 g/kg), FO (38.5 g/kg) or SDG + FO (combination) diets. The TAM group had TAM implants that provide a 5-mg TAM dose released over 60 d. TAM exerted an overall significant effect in increasing BMC, BMD, and biomechanical strength in femurs and lumbar vertebra. Without TAM treatment, SDG produced significant lower femur BMD (6%) while FO produced lower vertebrae BMC (8%) and BMD (6%). With TAM treatment, SDG and FO did not exert an effect on BMC and BMD at the femur or vertebra. SDG and FO produced no marked effect on biomechanical bone strength with or without TAM treatment. In conclusion, FS components did not significantly attenuate the positive effects on bone induced by TAM in this model system, indicating no apparent adverse effects on bone health.

Long-term effect on EMT6 tumors in mice induced by combination of laser immunotherapy and surgery.

Laser immunotherapy (LI) has been demonstrated to be a promising modality for cancer treatment. The present study was designed to further investigate the impact of LI combined with surgery. LI consists of a near-infrared laser, a light-absorbing dye (indocyanine green, ICG), and an immunostimulant (glycated chitosan, GC). ICG and GC were intratumorally injected, followed by laser irradiation. Female BALB/c mice bearing EMT6 tumor cells were divided into 4 groups: control, LI, LI followed by immediate surgery resection of residual tumor (LI + S(0wk)), and LI followed by surgical removal of residual tumor after 1 week (LI + S(1wk)). Successfully treated mice from all treatment groups were rechallenged twice with 10(5) and 5 × 10(5) EMT6 cells, respectively. The LI + S(1wk) group had the highest survival rate (72%) after 90 days, whereas the mice survival rates of the LI + S(0wk), LI, and control groups were 50%, 46%, 0%, respectively. The median survival times of control, LI, LI + S(0wk), and LI + S(1wk) groups were 32, 66, 74, and 90 days, respectively. Survival rates of the treated mice after the first and second tumor rechallenges, ranging from 73% to 95%, were not significantly different among the 4 groups (P > .05). The results show that LI is a useful tool for the treatment of tumor-bearing mice. Long-term antitumor effect can be induced by LI. They also indicate that combination of LI with surgery can further improve the therapeutic efficiency of LI.

Seasonal modulation of post-resection breast cancer metastasis.

BACKGROUND: Human breast cancer incidence, histopathologic grade, invasiveness, and mortality risk vary significantly throughout each year. In order to better understand this seasonal cancer biology, we investigated the circannual pattern of post-resection breast cancer metastasis, under genetically and environmentally controlled conditions. METHODS: Over a span of 14 consecutive years, we conducted 22 similar experiments to investigate metastatic biology of breast cancer among 1,214 C3HeB/FeJ female mice. All mice were kept in temperature-controlled environment with 12 h light:12 h dark photoperiod, with food and water freely available, from birth until death. At 10-13 weeks of age, each mouse received 20,000 viable syngeneic mammary cancer cells subcutaneously and the tumor bearing leg was resected 10-12 days after tumor inoculation for potential cure. Once 10% of resected mice were found moribund, due to autopsy proven pulmonary metastases, all remaining mice were sacrificed and metastatic lung nodules were counted. RESULTS: The incidence of post-resection pulmonary metastasis was not randomly distributed throughout the year, but peaked prominently in Summer and Winter. Although tumor volume at resection was strongly associated with metastatic potential, a significantly higher probability of pulmonary metastasis was observed if surgery was performed in Summer and Winter, regardless of tumor volume at resection, compared to Spring and Fall. CONCLUSION: These results support the likelihood that human breast cancer seasonality is real and of biological origin. There are implications of this cancer chronobiology for breast cancer prevention, screening, diagnosis, and treatment.

Flaxseed and its components reduce metastasis after surgical excision of solid human breast tumor in nude mice.

This study determined the effect of 10% flaxseed (FS) and its components, secoisolariciresinol diglycoside (SDG) and flaxseed oil (FO) alone or in combination (SDG+FO), on the metastasis and recurrence of human breast tumor after excision in nude mice. Mice were injected orthotopically with human breast cancer cells (MDA-MB-435) and fed basal diet (BD). When the tumors reached an average size of 110 mm(2) (0.9 g), surgical excisions were performed, and the mice were assigned to one of five diet groups for 7 weeks. The total incidence of metastasis was significantly lower in the FS, SDG, and SDG+FO groups. Reduced lung and lymph node metastases were observed in the FS and SDG+FO groups. In the FS and FO groups, a greater reduction in lung and total metastases was found when excised tumors were 0.9 g. There was no significant difference in tumor recurrence among groups. In conclusion, FS and its components inhibited tumor metastasis but not tumor recurrence after surgical excision of the primary tumor.

Gene-engineered T cells as a superior adjuvant therapy for metastatic cancer.

The major limiting factor in the successful application of adjuvant therapy for metastatic disease is the lack of adjuvant specificity that leads to severe side effects. Reasoning that T cells of the immune system are highly specific, we generated tumor-specific T cells by genetic modification of mouse primary T cells with a chimeric receptor reactive with the human breast cancer-associated Ag erbB-2. These T cells killed breast cancer cells and secreted IFN-gamma in an Ag-specific manner in vitro. We investigated their use against metastatic breast cancer in mice in an adjuvant setting, and compared their effectiveness with the commonly applied adjuvants doxorubicin, 5-fluorouracil, and herceptin. Mice were inoculated orthotopically with the human erbB-2-expressing spontaneously metastatic mouse breast cancer 4T1.2 in mammary tissue, and the primary tumor was surgically removed 8 days later. Significant metastatic disease was demonstrated in lung and liver at the time of surgery on day 8 with increased tumor burden at later time points. T cell adjuvant treatment of day 8 metastatic disease resulted in dramatic increases in survival of mice, and this survival was significantly greater than that afforded by either doxorubicin, 5-fluorouracil, or herceptin.

Adjuvant intraoperative photodynamic therapy diminishes the rate of local recurrence in a rat mammary tumour model.

The use of photodynamic therapy (PDT) as an adjunct to curative tumour resection was investigated in a tumour recurrence model, using rat mammary adenocarcinoma BN472. Tumours were inoculated subcutaneously in 60 animals and resected after 21 days of growth. Immediately after removal, the operation site was exposed to 320-450 nm light of 0.1 W cm-2 and 60 J cm-2 after photosensitisation with either Photofrin (5 mg kg-1 i.v. 48 h before illumination) or 5-aminolaevulinic acid (ALA) (2 mg ml-1 in drinking water for 9 days). Porphyrin concentrations were measured in tissue samples. After 28 days, animals treated with adjunctive PDT had a significantly longer tumour-free interval than controls (P < 0.01); median 25 days (Photofrin), 18 days (ALA), 14 days (controls). Moreover, in the PDT groups significantly fewer rats had lymph node metastasis. A prophyrin concentration ratio between tumour and mammary tissue of 2:1 was found after Photofrin and 4:1 after ALA. The results indicate that adjuvant intraoperative PDT may be a safe and effective method of destroying residual tumour, thereby preventing locoregional tumour recurrence.

The effect of Nd:YAG laser-induced hyperthermia on local tumor recurrence in experimental rat mammary tumors.

The influence of Nd:YAG laser hyperthermia (45 degrees C for 20 min) on local tumor recurrence followed by CO 2 laser or scalpel excision was studied on 150 F344 female rats that were implanted with R3230AC mammary tumor in the mammary ridge. The development of local tumor recurrence was observed for 39 days postoperatively. All groups undergoing CO 2 laser excision showed a significant reduction in local tumor recurrence (p less than 0.05) compared with the scalpel technique. Animals that underwent CO 2 laser excision and wound sterilization 48 h following laser hyperthermia demonstrated the lowest recurrence when compared with scalpel excision (p less than 0.01). These results indicate that the local thermal effect achieved by laser hyperthermia or laser sterilization plays an important role in the reduction of local tumor recurrence and augments complete local tumor resection.

Chemopreventive efficacy of combined retinoid and tamoxifen treatment following surgical excision of a primary mammary cancer in female rats.

Dietary N-(4-hydroxyphenyl)retinamide (4-HPR; 3 mmol/kg diet) and s.c. injections of the antiestrogen, tamoxifen (Tx; 10 micrograms or 20 micrograms per rat, thrice weekly) were used together as adjunct chemopreventive therapy in groups of 39-40 female, Sprague-Dawley rats that each received an i.v. injection (50 mg/kg b.w.) of the mammary gland carcinogen N-methyl-N-nitrosourea (MNU). Treatment was started immediately following the surgical excision of the first (primary) mammary carcinoma from each MNU-treated rat and was continued for 180 days. When compared to the effect of treatment with 4-HPR or Tx (30 micrograms/wk) alone, the combination treatments significantly enhanced terminal survival and reduced nonrecurrent mammary cancer incidence and multiplicity. Data showing the incidence of rats bearing the first through fifth additional cancers to appear following surgical resection of a primary lesion demonstrate that combined treatment with 4-HPR/Tx was immediately and consistently more efficacious than either agent per se in suppressing subsequent tumor appearance. This effect was apparently related to the dose of Tx. These results suggest that combined treatment with 4-HPR/Tx is superior to that of either agent alone in blocking progression of incipient neoplastic lesions at both early and later stages of the process.

Plasma levels of a viral protein during adjuvant treatment: reflection of murine mammary tumor status and therapeutic effect.

The mouse mammary tumor and its associated virus, mouse mammary tumor virus, were chosen to test the possibility of using plasma levels of a Mr 52,000 viral glycoprotein (gp52) as a means for monitoring changes in tumor status during surgical adjuvant cyclophosphamide:doxorubicin (Adriamycin):5-fluorouracil treatment. Analysis of tumor recurrence and plasma gp52 concentrations during the postoperative period demonstrated that both parameters were significantly decreased in the group receiving cyclophosphamide:doxorubicin:5-fluorouracil treatment. This observation suggests that plasma gp52 levels may be a useful alternative measure of therapeutic effect during surgical adjuvant treatment. A retrospective analysis of gp52 plasma levels and tumor status of individuals during treatment has revealed the following associations. (a) An early sharp postsurgical elevation in plasma gp52 level was associated with subsequent death of treated animals. (b) Maintenance of postsurgical gp52 levels at a low level (less than or equal to 4.2 ng/ml) during and after treatment was characteristic of all tumor-free survivors. (c) A gradual rise in plasma gp52 level accompanied CAF-delayed tumor recurrence. gp52 levels increased in all treated animals 2 wk prior to detectable tumor regrowths, resulting in a statistically significant increase in mean gp52 level (2.2 to 5.4 ng/ml). However, the magnitude of this increase was small for the majority of animals with tumor regrowths, and greater, more definitive elevations in plasma gp52 levels were only detected at the time of frank tumor recurrence. In addition, comparisons of early mean gp52 levels (8 to 10 days after surgery) for controls and for animals receiving various forms of alternative treatment have indicated that differences in gp52 levels reflect subsequent differences in recurrence rates. The present data, obtained during surgical adjuvant treatment of BALB/c X DBA/8 F1 mice and viewed in a retrospective fashion, demonstrate that plasma gp52 concentrations reflected therapeutic effects.

The contribution of thermo-moxibustion to surgical treatment in transplanted mouse mammary carcinoma.

BALB/C mice bearing progressive transplanted mammary carcinoma were treated by surgical removal of the tumor mass either with or without thermo-moxibustion, applied to the GV 14-point-equivalent. A surgical removal of the tumor, 14 days post-inoculation resulted in 61% of deaths compared with 90.0% of deaths in the sham operated control. By the addition of the thermo-moxibustion therapy, the mortality rate, in the surgically treated group was reduced to 37.5%. Surgical removal of the tumor mass at day 17 post-inoculation resulted in 70% death while surgery supported by thermo-moxibustion protected the animals to the range of 40% death. Surgical removal of the tumor mass followed by local heterologous immuno-therapy was very effective when applied 14 days post-inoculation (12.5% death only). However, the same procedures applied at day 17 post-inoculation were not effective (80% death). Surgery and moxibustion together were more effective than surgery alone. Surgery and immunotherapy were very effective when applied from day 14 post-inoculation. Thermo-moxibustion as the sole treatment was effective when applied either before or very close to the tumor cell inoculation (35% of death and 33% of death respectively, as compared to 61.7% death in the control). Thermo-moxibustion applied before and after tumor cell inoculation was more effective (15% death rate). Thermo-moxibustion either alone or in conjunction with surgery is a contribution to the protection of BALB/C mice against the early and the late development of mouse mammary carcinoma.

Multimodal primary cancer treatment (adjuvant chemotherapy): current results and future prospects.

In the 1970s chemotherapy has been successfully incorporated into curative primary treatment programs for various adult malignancies so that it is no longer solely palliative treatment for advanced disease. For at least three malignancies and tentatively a fourth (breast and colon carcinoma, osteosarcoma, and melanoma), certain groups of patients have had longer disease-free survival produced by the use of chemotherapy after surgical removal of the primary lesion. The potential impact on cancer mortality from these treatment results is obvious. We review here the fundamental laboratory concepts that have led to human trial of multimodal primary therapy regimens. Data from numerous clinical trials are analyzed, with delineation of the problems encountered in the interpretation of their results.

Comparison of adjuvant chemotherapeutic activity against primary and metastatic spontaneous murine tumors.

Metastatic tumor incidence in BALB/C X DBA/8F1 female mice was examined in the presence and absence of adjuvant chemotherapy. Following surgical removal of spontaneous mammary adenocarcinomas, phenylalanine mustard, adriamycin, and 5-fluorouracil (PAF) were administered at 4, 2, and 50 mg/kg, respectively, once a week for six injections. Recurring tumors and new tumors developing in other breasts over the next 6 months were noted and surgically removed to allow time for originally undetectable pulmonary metastases to develop or to regress completely. This regimen of PAF significantly decreased original tumor recurrences from 58% in controls to 36% in treated mice. New tumor development also was significantly reduced during the 5 weeks of PAF therapy and for 8 weeks thereafter. However, the incidence of pulmonary metastasis was unaffected by the chemotherapy, being 42% in controls and 37% in PAF-treated mice. About 30% of these metastases would have been undetectable at the time of original surgery. The findings stress the importance of developing agents and/or schedules that will specifically affect metastatic cells when administered early to minimal numbers of tumor cells. This system represents a stringent clinimimetic model for evaluating adjuvant chemotherapy in this regard.