Cell surface modification in the treatment of experimental cancer: neuraminidase or concanavalin A

Lipid Bound Sialic Acid in Cancer Patients

Serum lipid-bound sialic acid (LSA) was measured with a recently described procedure in 108 healthy subjects and in 138 patients with a variety of solid tumors and hematologic malignancies. At the time of serum sampling, 128 patients had active disease and 10 patients had no evidence of disease. LSA was elevated in 104 of 128 (81.2%) patients with active disease, while carcinoembryonic antigen, analyzed in 74, was elevated only in 21 (28.4%) (P < 0.05). Sensitivity of the serum LSA test ranged from 66% for breast and gastrointestinal cancer to 92% for lung cancer. In patients with lung cancer, ovarian cancer or Hodgkin's disease, LSA was correlated with the extent of disease and it also proved to be useful in following the course of disease. Our preliminary data indicate that this test can be used as a monitor of tumor burden.

Circulating levels in serum of total sialic acid, lipid-associated sialic acid, and fucose in precancerous lesion and cancer of the oral cavity

Total sialic acid (TSA), lipid-associated sialic acid (LASA), and fucose were estimated in sera of 35 patients with precancerous lesion of the oral cavity, 68 patients with cancer of the oral cavity, and 25 age- and sex-matched non-chewers of both tobacco and betal nut and nonsmokers as controls. Significant elevation in the serum levels of TSA and LASA were observed in patients with the precancerous and cancer lesions when compared with the controls. Serum TSA levels were elevated significantly in patients with cancer when compared with those with precancerous lesions. Circulating TSA and LASA levels were found to reflect tumor burden and correlated well with stage of the disease. However, serum fucose levels did not show an increase corresponding to stage of the disease. The results suggests that combined evaluation of these markers may be useful in predicting early malignant change and also in assessing the spread and invasiveness of the disease in cancer of the oral cavity.

Fibronectin and sialic acid levels in human meningiomas and gliomas

In this study, fibronectin and sialic acid levels have been assayed in human meningiomas and gliomas. The mean fibronectin and sialic acid levels for human meningiomas were 22.01 +/- 9.70 micrograms/mg protein and 19.58 +/- 4.89 micrograms/mg protein, respectively, and for human gliomas were 27.30 +/- 13.70 micrograms/mg protein and 25.67 +/- 11.60 micrograms/mg protein, respectively, versus 9.23 +/- 5.40 micrograms/mg protein and 13.50 +/- 4.30 micrograms/mg protein for normal brain tissues. Fibronectin and sialic acid levels were significantly higher in human meningiomas (P < 0.01 and P < 0.05) and gliomas (P < 0.001 and P < 0.01) than control group. Also the mean fibronectin and sialic acid levels were found to be 18.27 +/- 7.08 micrograms/mg protein and 17.04 +/- 6.25 micrograms/mg protein in Grade I-II and 32.60 +/- 15.00 micrograms/mg protein and 29.50 +/- 11.60 micrograms/mg protein in Grade III-IV gliomas, respectively. Fibronectin and sialic acid levels were significantly higher in Grade III-IV gliomas than Grade I-II gliomas (P < 0.05).

Plasma sialic acid in patients with prostate cancer

Serum sialic acid (N-acetylneuraminic acid) was evaluated as a tumour marker for prostate cancer and compared with serum prostate specific antigen (PSA). The records of 35 patients suffering from prostate cancer (9 with bone metastases) were analysed and compared with those of 21 healthy individuals. Total serum sialic acid was significantly elevated among the cancer patients. Levels in patients with distant metastases were significantly higher than in those with locally restricted disease and normal individuals, whereas no such difference was seen between the latter 2 groups. A direct association between serum sialic acid and tumour T category and grade could not be established. The difference between the cancer and the control groups was reflected more significantly by PSA. As sialic acid lacks tumour specificity, it is not helpful in screening for prostate cancer, yet might contribute towards the early detection of tumour progression and metastases during both therapy and follow-up.

Modification of tumor cells by a low dose of Newcastle disease virus. Augmentation of the tumor-specific T cell response in the absence of an anti-viral response

The present study elucidates the mechanism whereby viral xenogenization of highly metastatic ESb lymphoid tumor cells increases tumor immunogenicity and syngeneic tumor-specific T cell responses in comparison to nonmodified tumor cells. It was found that the frequency of cytotoxic T lymphocytes specific for the Esb tumor-associated transplantation antigen (TATA) and the cytotoxic anti-tumor activity in bulk cultures of immune spleen cells were significantly increased (by factor 3 and 25, respectively) when using virus-modified tumor cells. An amplified response was observed both in vivo and in vitro which might explain the demonstrated effectiveness of this approach for postoperative immunotherapy of ESb metastases. For the stimulation of tumor-specific cytolytic T lymphocytes (CTL) the ESb tumor cells which are highly metastatic were infected with an avirulent strain of the paramyxovirus Newcastle Disease Virus (NDV). Infection of ESb cells with low amounts of NDV was sufficient to lead to an increase in cytolytic activity of tumor-specific CTL after sensitization in vivo and restimulation in vitro. In a sensitive limiting dilution mixed leukocyte-tumor cell microculture system the direct effect of viral modification on the frequency and specificity of CTL was investigated. The number of ESb-specific CTL per spleen could be raised from about 3300 (without modification) to 9100 by both in vivo and in vitro application of ESb-NDV. One application of ESb-NDV (in vivo or in vitro) increased the number of CTL to 4900 and 4600, respectively. In split-type experiments it could be shown at the clonal level that viral modification did not alter the specificity of ESb-specific CTL.(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of epithelial cell surface carbohydrates during experimental oral carcinogenesis in the rat

Cell surface glycoconjugates were investigated in a rat model of oral chemical carcinogenesis. The lectins Griffonia simplicifolia (GS-I-B4; specific for alpha-D-galactosyl end groups) and Ulex europeus (UEA-I; specific for alpha-L-fucosyl groups) were examined microspectrofluorimetrically in the oral epithelium of rats painted with the carcinogen 4-nitroquinoline N-oxide (4NQO) and compared with those treated with solvent alone. After labelling with GS-I-B4, the fluorescent intensity of the basal and parabasal epithelial cells was significantly less after 9 months of 4NQO treatment and in overt squamous cell carcinomas compared to controls. The fluorescent activity of the spinous epithelial cells in the non-invasive tissues treated with 4NQO and in the well differentiated (sites of keratin elaboration) malignant epithelium of squamous cell carcinomas was unchanged after labelling with UEA-I. UEA-I failed to stain undifferentiated (areas lacking keratin) malignant epithelium. The findings indicate that alpha-D-galactosyl residues are diminished on the membranes of premalignant and malignant rat epithelial cells. The expression of alpha-L-fucosyl groups, however, remains unchanged in premalignant rat oral epithelium and is closely correlated to the presence of keratin in the malignant epithelium of squamous cell carcinomas.

Transitional mucosa and survival in human colorectal cancer

The mucosa in 100 segments of colon and rectum resected for cancer were examined using light microscopy and histochemical techniques. The extent of abnormal or transitional mucosa was defined for each case. Transitional mucosa was present in 93 of 95 adenocarcinomas and one malignant melanoma. The average total length of transitional change was 3.4 cm the maximum length was 19.5 cm. An inverse correlation was observed between the survival and the length of transitional mucosa around locally invasive (Dukes' B) carcinomas (P = 0.005). This may be related to increased amounts of sialic acid in transitional mucosa and the ability of sialic acid to depress tumor immunogenicity. The raised levels of sialic acids in transitional mucosa may have practical value in assessment of prognosis in colorectal cancer.

Serum sialic acid and CEA concentrations in human breast cancer

The concentration of bound sialic acid in the sera of 56 normal subjects and 65 subjects with breast cancer was measured, in order to determine (1) whether serum sialic acid concentrations are raised in breast cancer and (2) whether the concentration of sialic acid in serum reflects tumour stage. The amount of sialic acid in serum was compared to serum carcinoembryonic antigen (CEA) values. Urinary hydroxyproline and serum alkaline phosphatase concentrations were used as indicators of bone and liver involvement. Erythrocyte sedimentation rate (ESR) was also measured. Significantly elevated serum sialic acid concentrations were found in breast cancer, and showed correlation with tumour stage. Serum sialic acid values did not correlate with CEA values. The results suggest that measurement of serum sialic acid concentrations may be of adjunctive value in assessing tumour stage.

Serum sialic acid elevations in malignant melanoma patients

Elevated membrane sialic acid (n-acetyl neuraminic acid) concentration may be a general phenomenon associated with malignant or transformed cells. In this study, sera from 30 normal persons and 25 melanoma patients were examined to determine first, if serum sialic acid elevations were associated with malignant melanoma, and second, if there was a relationship between tumor burden and serum sialic acid level. Significantly elevated sialic acid concentrations were found in the melanoma patients (p less than 0.005), and levels tended to be greater in those with a large tumor burden (p less than 0.05). Thus, increased serum sialic acid could prove to be a valuable clinical monitor of change in tumor burden as a result of therapy or change due to recurrence of disease following treatment.

[Biology of lectins and their application in clinical biochemistry (author's transl)]

Lectins are proteins or glycoproteins, originally isolated from plant seeds. Characteristics are their ability to bind glycoproteins or glycolipids depending on the carbohydrate residues. The present review describes the structure of the lectins, their binding specificity and their functions with respect to precipitation of glycoproteins, agglutination of cells, transformation of lymphocytes and toxic action. Recently, lectin-analogs have been described in rabbit liver, which are responsible for hepatic uptake of circulating glycoproteins. The regulation of this process is intimately linked to the terminal N-Acetylneuraminic acid (NA-NA). Moreover, its significance is shown during fetal development, oncogenic transformation, immunologic recognition as well as homostasis. Due to the different terminal carbohydrate residues, glycoproteins of adult, fetal or transformed cells can be separated using affinity chromatography. Besides the purification of glycoproteins, lectins are also used for the separation of intact cells. Therefore the use of lectins is recommended for preparative and analytical methods, for the measurements of glycoprotein-turnover and for clinical diagnostics.

Neuraminidase and tumor immunotherapy

Preliminary results of first clinical studies with the enzyme neuraminidase call attention to a new kind of cancer treatment. This promising approach to tumor immunotherapy was entered into the clinical phase as a consequence of successful experimental studies in tumor-bearing mice, rats and dogs. In this review, the presently known and essential results of experimental and clinical studies on tumor immunotherapy by means of neuraminidase are presented as well as some necessary and critical considerations in this context. Moreover, out of a broad variety of results of biochemical and biological in vitro studies, it was attempted to select the more essential knowledge which could contribute to a better understanding of the still rather unclear in vivo mode of action of the enzyme neuraminidase. In a first brief paragraph (1.0), the biochemically characteristic data of the enzyme neuraminidase is presented. In the second section (2.0), the basic knowledge about the effects of neuraminidase on cell behavior is rather amply contained. Here, on the one hand, the biophysical and biochemical alterations are mentioned, the so-called ""unmasking'' effects are reconsidered and, on the other hand, the effects on the immunologically responding cell are discussed. In a third section (3.0), the diverse findings from animal experiments using neuraminidase-treated tumor cells are confronted, whereby tumor transplantation experiments and tumor therapy experiments are dealt with separately. The last section (4.0) reports about the first clinical studies with neuraminidase-treated autologous as well as homologous tumor cells, which partly brought about rather surprising and astonishing success. On the basis of recent findings by the study group of the authors, the more prior and sometimes discrepant results of various groups are critically considered. The problems of alteration of antigenicity and of other properties of cells through splitting off membrane-bound neuraminic acid, the facts of adjuvanticity of neuraminidase itself, the relation of successful therapy to dose dependency as well as the relation of undesirable methods for tumor mass reduction to the immunological responsiveness of the tumor bearer were especially looked into.

The tumor specific immune response of experimental active-specific immunotherapy

Evidence for augmentation of antigenic recognition was investigated by measuring antigen-specific lymphocyte stimulation in animals which were minimally immunized with Con A-modified tumor cells. Comparison of lymphocyte stimulation response was made to animals immunized with unmodified tumor cells or sham immunization. Markedly heightened, tritiated Thymidine incorporation was observed in the lymph node cells from animals immunized with Concanavalin A-modified tumor cells, while minimal response was observed in control hosts. These preliminary findings imply that Con A-modified tumor cell immunotherapy may work by augmenting the host's capacity to recognized minimal differences in immunogenicity between tumor cells and the normal cells or origin. This modulation of the immune response may be a key factor in the success of active-specific immunotherapy.

The combined effect of radiotherapy and neuraminidase-treated tumor cells on 3-methylcholanthrene-induced fibrosarcoma

Active immunotherapy with tumor cells treated in vitro with Vibrio cholerae neuraminidase (VCN) plus mitomycin C augments the antitumor effects of local x irradiation in the treatment of firmly established methylcholanthrene-induced fibrosarcoma, MC-43, in syngeneic C3H/HeJ female mice. In most experiments, the inhibition of tumor growth was greater when VCN-treated tumor cells were combined with local irradiation than could be achieved with VCN-treated tumor cells or local irradiation alone. Even in those experiments in which the immunotherapeutic effect of VCN-treated cells was negligible, the combination of radiotherapy and immunotherapy appeared to be greater than irradiation alone. Similarly, total permanent regression of established tumors occurred more frequently after combined therapy than after immunotherapy or radiation therapy alone.

Relationship of causative factors in spontaneous regression of cancer to immunologic factors possibly effective in cancer

In a book written by Everson and Cole (1966) on spontaneous regression 176 examples of the phenomenon were encountered in the medical literature from 1900 to 1964, supplemented by cases referred by friends. No common denominator of explanations were found. Various types of trauma (e.g., biopsy, incomplete excision), transfusions, infection, hormone changes, drugs, etc. were encountered as possible causative factors. Most significant of all factors was encountered in the 13 examples of spontaneous regression of the bladder; in this series regression of the tumor occurred in 10 after transplantation of the ureters out of the bladder. A consideration and discussion of various reactions in human beings associated with therapeutic regressions have been reviewed hoping to develop a correlation between the two types of regression. At the time of publication of our monograph 9 years ago we were unable to suggest any mechanisms which might explain the regressions. However, since that time so many advances have been made in immunology that it appears now that a stimulation of the immune process might explain most of the regressions. We are just beginning to learn a few methods of stimulating the immune process. Use of BCG is one of the best examples of this stimulating process; other bacterial agents, or fractions, are known to have this action. No doubt there are innumerable others unknown, some of which might explain spontaneous regressions. It would appear that hormonal changes might be responsible for many of the regressions but this author doubts it explains many. More is known at the present time about cellular immunity than humoral immunity, but greater possibilities surely lie in humoral immunity. The blocking and unblocking activities developed by the Hellströms and associates are no doubt important. Immunoglobulins exert a very important role in the immune process; antibodies may consist of immunoglobulins but much more needs to be known before this relationship can be understood. The recent report (Amery, 1975) that levamisole (given at the time of resection of the lung for carcinoma) improves patient survival is exciting. Amery believes the drug may prevent the hematogenous spread of the tumor during surgery and/or may decrease the immunosuppression caused by a major operation.