{'fraction_non_alphanumeric': 0.027101769911504425, 'fraction_numerical': 0.014933628318584071, 'mean_word_length': 5.050167224080267, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Ratio of IgG: IgM antibodies to sialyl LewisX and GM3 correlates with tumor growth after immunization with melanoma‐cell vaccine with different adjuvants in mice

Human melanoma cells (from biopsies and culture) express sialyl‐Lewisx and sialyl Lewisa, the ligands for ECAM. These ligands may facilitate tumor progression and metastasis in human cancers. To test whether the antibodies to these ligands inhibit tumor progression, IgG and IgM responses to sLex and sLea were induced in C57BL/6j mice (n = 76) by immunization with human melanoma cells, with or without adjuvants (BCG, MPL, KLH). Control mice were treated with saline or BCG. Tumor growth and antigen expression were monitored after challenge with B16 mouse melanoma cells expressing sLex, sLea and the ganglioside GM3. Tumor growth was reduced in mice immunized with BCG alone or cells with BCG or MPL, while tumors in mice receiving cells without adjuvants grew larger than in the control. Augmentation of IgM titers to sLex and GM3 after immunization with BCG, or with cells with BCG or MPL correlated with retarded tumor growth, while increased IgG titers to sLex significantly correlated with aggressive tumor growth in mice immunized with cells without adjuvants. SLex, sLea and GM3 were expressed in tumors from mice treated with saline or BCG. SLex expression, in particular, was lost in tumors growing in mice immunized with cells with or without adjuvants. Anti‐sLex antibodies may promote or prevent tumor growth by antigenic modulation or by cytotoxic killing of tumor cells. Since early anti‐sLex IgM correlated with tumor regression, in contrast to anti‐sLex IgG, it may serve as a potential early endpoint for the effectiveness of melanoma vaccines expressing the antigens. Int. J. Cancer 75:117–124, 1998.© 1998 Wiley‐Liss, Inc.