Correlation between anti-tumor effect and delayed hypersensitivity induced by topically applied OK-432 with histological findings

Delayed hypersensitivity (DH) against OK-432 was induced in BALB/c mice by injecting 2 KE of OK-432 with Freund's incomplete adjuvant into foot pads. One week after presensitization with OK-432, 2 X 10(5) cells of Meth A tumor were implanted subcutaneously in all mice, followed by intratumoral injection of 1 KE of OK-432 five times every other day starting at 7th day in experimental group. Tumor growth was significantly inhibited in the OK-432 presensitized group comparing to non-sensitized group. In experimental groups marked inhibition was observed in mice which were injected with OK-432 intratumorally 2 to 3 weeks after presensitization. This effect correlated well with delayed hypersensitivity against OK-432. Histological changes after intratumoral injection of OK-432 were examined in order to analyse the mechanism of this effect. The main finding of OK-432 injected specimen by H.E. staining were degeneration of tumor cells and infiltration of inflammatory cells. These changes were stronger in OK-432 presensitized mice. By beta-D-galactosidase staining accumulation of macrophages was found both inside the tumor and the surrounding tissue, and these macrophages increased in OK-432 presensitized mice. Immunoperoxidase staining with antiasialo GM1 anti-serum was also performed. Greater number of activate macrophages were observed to accumulate in the specimen of OK-432 presensitized mice than that of control mice. Some T cells were observed only around tumor tissues and not in the tumor of both presensitized and unsensitized mice. These results suggest that the activated macrophages play a major role in the augmentation of antitumor effect by presensitization with OK-432.     

The clinical efficacy of intratumoral OK-432 administration in advanced cancer patients

The clinical efficacy of intratumoral (IT) OK-432 immunotherapy in advanced cancer patients was investigated. Furthermore, the infiltration of lymphocyte subsets into the tumor tissues after the IT administration of OK-432 was also immunohistologically examined in order to analyze the mechanism of action of OK-432 immunotherapy. Forty-four patients with advanced cancer were treated with IT OK-432 immunotherapy. Ten KE (1 mg) of OK-432 was given either daily or on every second day and repeated as often as possible, the mean frequency of OK-432 injections being 18.1±14.5 times, ranging between 5 and 25 administrations. Thirty-one of the 44 patients were evaluable, 3 of whom (9.7 per cent) developed a partial response and 5 (16.1 per cent) a minor response. Intratumoral OK-432 immunotherapy, however, did not necessarily prolong the survival time. Leu 1, 3 and 7 reactive cells infiltrated into the tumor tissues treated by OK-432 injection, more frequently, when compared with cells which had been treated by recombinant TNF injection. Thus, it was suggested that IT OK-432 immunotherapy might be effective for the local control of tumor growth through the host mediated action, and that, in combination with systemic therapy, may enhance the clinical effects and prolong the survival time in advanced cancer patients.     

The clinical efficacy of intratumoral OK-432 administration in advanced cancer patients

The clinical efficacy of intratumoral (IT) OK-432 immunotherapy in advanced cancer patients was investigated. Furthermore, the infiltration of lymphocyte subsets into the tumor tissues after the IT administration of OK-432 was also immunohistologically examined in order to analyze the mechanism of action of OK-432 immunotherapy. Forty-four patients with advanced cancer were treated with IT OK-432 immunotherapy. Ten KE (1 mg) of OK-432 was given either daily or on every second day and repeated as often as possible, the mean frequency of OK-432 injections being 18.1 +/- 14.5 times, ranging between 5 and 25 administrations. Thirty-one of the 44 patients were evaluable, 3 of whom (9.7 per cent) developed a partial response and 5 (16.1 per cent) a minor response. Intratumoral OK-432 immunotherapy, however, did not necessarily prolong the survival time. Leu 1, 3 and 7 reactive cells infiltrated into the tumor tissues treated by OK-432 injection, more frequently, when compared with cells which had been treated by recombinant TNF injection. Thus, it was suggested that IT OK-432 immunotherapy might be effective for the local control of tumor growth through the host mediated action, and that, in combination with systemic therapy, may enhance the clinical effects and prolong the survival time in advanced cancer patients.     

Two-color flow cytometric analysis of splenic lymphocyte subpopulations in patients with gastric cancer

Lymphocyte subpopulations of the spleen were assayed in 26 patients with gastric cancer and 5 patients with benign disease using two-color flow cytometric analysis. The ratio of Leu 2a+·Leu 15+ cells, or suppressor T cells, in the gastric cancer patients was about 6 per cent, being higher than that in the patients with benign disease (p<0.05). There were fewer Leu 7+·Leu 11– cells, or natural killer-NK-cells, in the gastric cancer patients in stage III or IV than in those with stages I or II (p<0.05). The ratio of Leu 3a+·Leu 8– cells, or helper T cells, in the stage IV patients accounted for about 15 per cent of the splenic lymphocytes, which was less than that seen in the patients in stages I or II (p<0.05). The ratio of Leu 2a+·Leu 15– cells, or cytotoxic T cells, was approximately twice that of suppressor T cells. The pre-operative administration of lentinan plus OK-432 increased the ratio of Leu 4+·HLA-DR+ cells, or activated T cells, and cytotoxic T cells (p<0.05 and p<0.01, respectively). The above results suggest that lymphocyte subpopulations in the spleen may have more immuno-suppressive potential in proportion with the stage of gastric cancer, but that this reduced immune state may be altered when lentinan and OK-432 are given to these patients.     

Immunohistochemical study using a double fluorescent staining on the regional lymph nodes of gastric cancers]

For the purpose to investigate the immunological anti-tumor function of lymphocytes in the regional lymph nodes of gastric cancer, a double staining procedure using several monoclonal antibodies against the surface membranes of T and NK cells with fluorescent antibody technique was conducted. The number of CD11b+ cells out of CD8+ cells was small with almost all being CD11b- belonging to cytotoxic T cells. Leu8+ cells and Leu8- cells out of CD4+ cells were recognized in equal numbers and were reciprocal. The ratio of CD4+ Leu8-/CD4+ demonstrated an increase in the group injected with OK-432. The ratio of OKT9+ or OKIa1+ occupied in CD8+ or CD4+ cells was only several percent, and few in number. An increase for the ratio of CD4+ OKT9+/CD4+ was observed in the group injected with IL-2. Similar increases for the ratio of CD4+ OKIa1+/CD4+ were obtained in the group injected with OK-432 and in the metastatic group, respectively. The Leu7+ CD16+ cells were not observed. The Leu7- CD16+ cells were observed in a part where metastases were focused. These results indicated that lymphocytes in regional lymphocyte of gastric cancer might hold the hidden anti-tumor effect, but did not display the full function without preoperative intratumor injection of BRM such as IL-2 or OK-432.     

Intratumoral injection of biological response modifier (BRM)

Specific antitumor effects of lymphokine activated lymphocytes obtained from tumor-bearing mice after intratumoral injection of IL-2 were studied. Furthermore, effects of preoperative endoscopic intratumoral injection combined IL-2 and Lentinan or OK-432 were clinically studied against gastric cancer. The results were as follows: After intratumoral consecutive injection of recombinant human IL-2 (rhIL-2), the splenocytes of these mice were cultured with rhIL-2 and the effector cells were obtained. 1) Adoptive transfer of the effector cells specifically diminished the size of the host tumor and prolonged the life span of the mice. 2) The analysis of the surface antigens indicated the Thy1.2, Thy1.2+ L3T4+ cells increased in the effector cells as the specific cytotoxicity of them were augmented. 3) Preoperative endoscopic intratumoral injection combined IL-2 and Lentinan or OK-432 induced immunocytes including antigen-presenting cells in the site of the gastric cancer, and increased the IL-2R and the LAK activity of PBL. This method was considered as effective as an adjuvant treatment of gastric cancer surgery as a in vivo sensitization.     

Immunohistochemical study of the regional lymph nodes in gastric cancer

Immunohistochemical study with various monoclonal antibodies against the mononuclear cell surface antigen was performed on the regional lymph nodes of gastric cancer through Avidin-Biotin Complex (ABC) method. In the paracortical area (P.C.) of those lymph nodes without the metastasis of gastric cancer, T cells were dominant, and OKT3 positive (OKT3+) cells and OKT4+ cells were diffusely present, while OKT8+ cells were occasionally recognized. In the sinus, subsets of the above T cells, and OKT9+ cells and OKT10+ cells were observed. In the germinal center (G.C.), mantle zone (M.Z.) and primary follicle (P.F.), which were B cell regions, OKIa1+ cells and Leu12+ cells were diffusely present. OKB7+ cells, OKT9+ cells, OKT10+ cells and Leu7+ cells were also noted in G.C.. Leu8+ cells were observed in M.Z. and P.F.. OKIa1+ cells were occasionally noted in P.C. and sinus. In the lymph nodes with the metastasis, decrease of OKT4+ cells and increase of OKT8+ cells were noted in comparison to the lymph nodes without the metastasis. Using the tissue double fluorescence staining method, it was found that about half of the OKT4+ cells were helper T cells. The majority of OKT8+ cells were identified as cytotoxic T cells or their precursors. By preoperative endoscopic administration of OK-432 or PSK into the tumor, the IL-2 receptor+ cells, or OKM1+ cells and OKT4+ cells increased in the regional lymph nodes and the antitumor activity was intensified.     

Intratumoral injection of OK-432 in conjunction with fibrinogen greatly enhances antitumor effect on colorectal carcinomas]

We found that antitumor effect of OK-432, a lyophylized preparation of an attenuated strain of streptococcus pyogenes, on colorectal carcinoma was greatly augmented when it was injected intratumorally in conjunction with fibrinogen. Twenty cases of colorectal cancer received intratumoral injection of 5 KE of OK-432 mixed with 80mg of fibrinogen including factor-XIII and 1ml of aprotinin at the time of endoscopic examination. Changes in the shape of the tumors were observed endoscopically within a few days after injection, and in most cases, decrease in the height of tumor margin was noted. Histopathological findings on surgically resected specimens revealed that the fine meshwork of fibrin was formed at the injected site soon after the injection, and a marked infiltration of inflammatory cells including neutrophils, plasma cells, macrophages, eosinophils and lymphocytes. Such granulomatous changes developed over 7 days after injection, and the degradation of tumors were observed. By 14 days after the injection, tumor tissues were largely replaced with granulomas, and shrinkage of tissues were observed. These findings indicated that fibrinogen including factor-XIII and aprotinin has a potential ability to augment the immunoreaction induced by biological response modifiers, and intratumoral injection of OK-432 in conjunction with fibrinogen solution was superior to intratumoral injection of OK-432 alone as the local immunotherapy of colorectal cancer.     

Hemodynamic effects of a large dose injection of OK-432 (picibanil)

Intratumoral administration of a large dose of OK-432 has two antitumor functions; a direct cytotoxic effect and an indirect effect through the host reticuloendotherial functions. It has been pointed out that this method, however, occasionally results in shock. Several investigators have suggested the importance of the use of general anesthesia to avoid such shock. In order to explore the hemodynamic effect of intratumoral injection of OK-432, a simulated experiment (OK-432 or saline intramuscular injection) was carried out utilizing 10 anesthetized and 10 unanesthetized dogs. In addition, hemodynamic alterations during the OK-432 administration were studied in nine patients under neuroleptal anesthesia. In both anesthetized and unanesthetized dogs, OK-432 intramuscular injection resulted in a slight decrease of the mean arterial pressure, left ventricular systolic pressure and cardiac output as compared with those of the saline injected dogs. The hemodynamic alterations, however, were minimal and were thought not to cause severe hemodynamic derangements. Clinical experiences also showed no serious hemodynamic effects by the OK-432 intratumoral injections. It was concluded that the OK-432 intratumoral injection appeared not to induce hemodynamic derangement when applied to euvolemic and hemodynamically stable patients.     

Improved therapeutic effect of sequential immunotherapy with cyclophosphamide, large doses of OK-432 and recombinant interleukin-2 in breast cancer patients with disseminated metastatic liver tumors

It has been generally agreed that the prognosis of widely spreaded "surgically unresectable" metastatic liver tumor originated from breast cancer is very poor. We reported here the result of clinical efficacy of sequential immunotherapy with intra-tumoral injection of large dose OK-432, after oral administration of cyclophosphamide during 7-10 days, and continuous perfusion of purified human recombinant interleukin-2 (rIL-2) from hepatic artery for the breast cancer patients with unresectable metastatic liver tumors. In all of 3 cases, metastatic liver tumor revealed overwhelming tumor reduction more than 50% of preoperative total tumor burden evaluated by computed tomography. Only 1 day after operation, large doses of OK-432 was injected intratumorally, both activity of Natural Killer (NK) cells and lymphokine activated killer (LAK) cells in peripheral blood lymphocytes were 5-20 folds augmented in all clinical trials. Serum tumor markers, i.e., Carcinoembryonic Antigen (CEA) and CA15-3, were rapidly decreased in all cases, respectively. Our clinical data indicate that intratumoral injection of large dose OK-432 and continuous administration of rIL-2 via hepatic artery, pretreated with cyclophosphamide, were clinically effective immunotherapy for reduction of metastatic liver tumor.     

Intratumoral administration of OK432 in rats with liver tumor

The approach to the treatment of unresectable liver tumor involves immunotherapy. Systemic administration of OK432 has been widely used in the treatment of malignant neoplasms. However, the most potent antitumor activity of the drug may be expected when it is administered intratumorally. The author evaluated the effect of intratumoral injection of OK-432 on the survival time, the immunological parameters (such as the NK activities of spleen cells and peritoneal exudate cells and the interferon production by spleen cells) and the tumor infiltrating lymphocytes (TIL) in the rats with liver tumor induced by feeding the hepatocarcinogen, 3'-methyl-4-di-methyl-aminoazobenzene. The mean survival time was significantly longer in the rats injected with OK432 intratumorally (I.T. group) than in the rats injected with OK432 intraperitoneally only (I.P. group) and in the rats injected with normal saline intratumorally (Control group). The immunological parameters significantly improved in the rats of I.T. group than in the controls. Intratumoral injection of OK432 increased the number of TIL, especially NK cells and suppressor/cytotoxic T cells. These beneficial effects could be responsible for the better survival time in the rats of I.T. group. The author concluded that the intratumoral OK432 administration therapy is effective for the treatment of the patients with unresectable liver tumor.     

Local immunotherapy with streptococcal preparation, OK-432 in superficial bladder tumors, and common antigens between OK-432 and the tumor

In 38 patients with superficial bladder, local immunotherapy with streptococcal preparation OK-432 has been performed. We investigated whether OK-432 was an effective biological response modifier (BRM) against bladder tumors or not, and the relationship between the common antigens which OK-432 shared with the tumors, and antitumor effects of OK-432. In six out of 28 patients treated by intravesical instillation, and three out of 10 cases treated by intratumor injection, tumors were eliminated endoscopically. In the other patients, the tumors did not change. The PAP study using an anti-OK-432 antibody, showed a positive reaction in 66.7% of the instillation cases and in 40.0% in the injection cases. In 66.7% of the patients with the common antigens treated by the instillation and in 75.0% of patients with the antigens treated by the injection, tumors were eliminated. However, the PAP study showed a positive reaction in 9.1% of the no-change cases treated by the instillation and in 14.3% out of the no-change cases treated by the injection. We concluded that OK-432 was a favorable BRM for topical immunotherapy against bladder tumor and the presence of the common antigens between OK-432 and tumor may enhance the immune response of patients and promote tumor regression.     

Analysis of tissue lymphocytes by double fluorescent staining--gastric cancer tissue and regional lymph nodes

An immunohistochemical study was performed on human lymphocytes in the tissue of gastric cancer, and also in the regional lymph nodes, by double fluorescent staining, using monoclonal antibodies. Leu3a+8+ cells (inducer T cells) which consist about 30 per cent of Leu 3a+ cells were seen in the tissue surrounding the gastric cancer. The other 70 per cent of Leu 3a+ cells were Leu3a+8- cells (helper T cells). In the lymph nodes they were noted in T cell areas in almost the same proportions, while in germinal centers, only Leu3a+8- cells were found. On the other hand, OKT8+Leu15- cells (cytotoxic T cells) were noted in a large number, while OKT8+Leu15+ cells (suppressor T cells) were few. Further, an increase of OKT8+Leu15- cells was seen around gastric cancer or metastatic cancer in lymph nodes. These immunohistochemical findings suggest that cytotoxic T cells are the main component in the tissue of gastric cancers and the regional lymph nodes. Increases in inducer T cells and helper T cells are probably required to induce cytotoxic T cells around the cancer tissue.     

A role of cytokines in OK-432 injection therapy for cystic lymphangioma: an approach to the mechanism

Purpose: This study examines cytokine levels of aspirates from cystic lymphangiomas after injection of OK-432 and over the course of several weeks to better understand the process of tumor regression.Methods: Fluids aspirated from lymphangioma cysts of 3 patients were collected sequentially before and after OK-432 injection. Mononuclear cells (MNCs) were separated and cultured with or without OK-432. Vascular endothelial growth factor (VEGF), soluble VEGF receptor 1 (sVEGFR1), sVEGFR2, transforming growth factor beta-1 (TGF-β1), interleukin (IL)-6, IL-8, IL-12+p40, tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) levels in the supernatants of the aspirates and the culture supernatants of MNCs were then measured by ELISA.Results: The aspirates exhibited a marked elevation in IL-6, IL-8, VEGF, and TGF-β1 levels for a few weeks after the OK-432 injection. IL-6, IL-8, IL-12+p40, TNF-α, and IFN-γ levels were elevated in the culture supernatants of the MNC cultured with OK-432 for up to 9 days. All the tumors regressed significantly, with sclerotic change, within 3 months after OK-432 injection.Conclusions: Cytokine production is maintained for a few weeks after OK-432 injection. Fibrotic changes may be another main mechanism in tumor regression in addition to cytotoxic effects on lymphangioma cells. A close relationship between cytokines from intracystic cells and lymphangioma cells is suggested.     

Clinical studies on streptococcal preparation (OK-432) combined with mitomycin-C, 5-FU and cytosine arabinoside in advanced cancer patients.

Streptococcal preparation (OK-432), a new type of anti-cancer agent, was given to the patients with advanced cancer in combination with Mitomycin-C, 5-FU and Cytosine arabinoside. OK-432 was administered intramuscularly with a daily dose of 2.0 KE consecutively or locally into the tumor with a large-dose of 100 KE. Most cases tolerated the long term administration of OK-432 without any severe side effects and the highest dose reached was 314 KE during 161 days of treatment. Of the 53 patients evaluated, 31 were given the initial large dose intratumoral OK-432. Thirteen were judged 0-C and Category 1 according to the Karnofsky criteria for a response rate of 44.8 per cent as compared with 12.5 per cent in the group without the initial large-dose administration.     

Management of malignant ascites by intraperitoneal injection of OK-432. Possible mechanism of the reduction of original tumor mass volume

We studied the effect of intraperitoneal injection of OK-432 on the growth of original tumor mass in patients with malignant ascites and a possible mechanism of reduction of tumor volume. Sixteen patients with valuable original tumor mass and a large amount of ascites caused by gastro-intestinal cancer were studied. Tumor cells were separated from ascitic fluids and cultured in vitro before the study. Lymphocytes were collected from the fluids at varying intervals after intraperitoneal injection of OK-432 and cultured 24 hours in vitro. Effect of the culture supernatant on ascites-derived autologous tumor cell growth was examined in vitro using microplate assay. The results were as follows. 1) Reduction of tumor mass more than four weeks was found in 4 of 16 cases. 2) Before OK-432 injection, the culture supernatant from ascites-derived lymphocytes did not inhibit autotumor cell growth in vitro. But, the supernatant from lymphocytes which were collected from the ascites after OK-432 injection markedly inhibited tumor growth in all of 4 tumor mass reduction cases. In 12 non-reduction cases the supernatant slightly inhibited tumor growth only in 2 cases. 3) A similar growth inhibitory factor was detected in the mixed culture-supernatant of peripheral blood lymphocytes and OK-432 in vitro. 4) Preliminary studies indicated that the tumor growth inhibitory factor might be different from tumor necrosis factor and interferons. These results indicate that ascites-derived lymphocytes-producing factor may play an important role in reduction of tumor mass volume in patients with cancerous ascites.     

Immunoresponse of tissue infiltrating lymphocytes in bladder tumors

Local immunocompetence was evaluated immunohistochemically in patients with bladder tumors before and after local injections of an immunomodulator. The subpopulations of tissue infiltrating lymphocytes (TIL) were examined by staining six serial sections with Leu4, Leu7, Leu10, LeuM3, OKT4, and OKT8 antibodies. T cells predominated over B cells in 19 of 25 bladder tumors. T cell infiltration was prominent around tumor cells, and it was marked in non-invasive tumors. B cells were rare in the stroma. In patients with low-stage tumors, OKT8 cells were more prominent than OKT4 cells. NK cells accumulated within cancer nests but their infiltration was scanty in invasive bladder tumors. Before surgery, immunomodulators (OK-432, IL-2) were injected intratumorally. Their administration resulted in marked increase of T and NK cells, irrespective of the stage of disease; there was a slight increase in B cells. These findings suggest that local immunosurveillance plays a role against bladder tumors. Further studies are required to elucidate host immune responses in the microenvironment of the cancer site, as well as the systemic immune reaction.     

Augmentation of cytotoxicity of regional lymph node lymphocytes of gastric cancer after intratumoral injection of OK-432

Although regional lymph node lymphocytes (LNL) are thought to be a barrier of the immunological surveillance, their natural cytotoxicity is strongly suppressed. In this study, an immunopotentiator OK-432 (10K.E.) was injected into gastric cancer lesions under endoscopy 1 week before operation, and the effects on the cytotoxicity of LNL were examined by single cell assay. This assay is characterized by assessment of killer cell frequency in preventing the killer cells from recycling by their fixation in agarose, and by direct microscopic observation of both binding and killing phases. NK sensitive cell line K562 was used as target cells. By intratumoral injection of OK-432, the killer cell frequency of LNL in 8 out of 20 cases was elevated to almost equal level as that of peripheral blood lymphocytes. In clinical stages these 8 cases belonged to early stages (stage I 7 cases, stage II 1 case). In LNL subsets of OK-432 injected cases, the percentage of OKT8 positive cells was decreased and the ratio of OKT4 and OKT8 was significantly increased compared with non-injected group.     

Clinical studies on streptococcal preparation (OK-432) combined with mitomycin-C, 5-FU and cytosine arabinoside in advanced cancer patients

Streptococcal preparation (OK-432), a new type of anticancer agent, was given to the patients with advanced cancer in combination with Mitomycin-C, 5-FU and Cytosine arabinoside. OK-432 was administered intramuscularly with a daily dose of 2.0 KE consecutively or locally into the tumor with a large-dose of 100 KE. Most cases tolerated the long term administration of OK-432 without any severe side effects and the highest dose reached was 314 KE during 161 days of treatment. Of the 53 patients evaluated, 31 were given the initial large dose intratumoral OK-432. Thirteen were judged 0-C and Category 1 according to the Karnofsky criteria for a response rate of 44.8 per cent as compared with 12.5 per cent in the group without the initial large-dose administration.     

Multidisciplinary therapy using interferon and immunological evaluation for glioma patients: two-color analysis of T cell subsets]

We have employed IAR therapy [combination of postirradiation, chemotherapy and interferon (IFN)] for malignant glioma patients. Changes of lymphocyte fractions in patients were evaluated before and after IAR therapy, using a recently developed two-color analysis. Eight malignant glioma patients received irradiation, chemotherapy (ACNU) and immunotherapy (OK-432 and IFN-beta). Peripheral blood lymphocytes taken during hospitalization with IAR therapy (first half and latter half), and every 3 to 6 months for 2 years at the longest after IAR therapy were double-stained with FITC- and PI-labelled antibodies and two-color analysis was conducted by a FACS Analyzer. Six patients out of 8 survived for 6 months to 2 years, 2 died after 3 and 6 months, respectively. Leu-2a (suppressor/cytotoxic T), especially Leu-2a+ 15- (cytotoxic T) showed a high value. Leu-2a level decreased during treatment, and both Leu-2a+ 15- and Leu-2a+ 15+ (suppressor T) values decreased. Two thirds of the patients showing an increased Leu-2a+ 15+ level died. Leu 3a (helper/inducer T), especially Leu-3a+ 8+ (inducer T) level decreased, but Leu-3a+ 8- (helper T) level increased during treatment. The level decreased in the worse patients. Leu-3a/Leu-2a ratio was low, but it increased during treatment as compared with the results of conventional therapy. Leu-7, Leu-11a, NK activity, and gamma-IFN productivity were further studied. Treatment combined with IFN revealed an influence on the T cells resulting in an increase of helper T level and suppression of suppressor T level.