Immunoglobulin mRNA and Protein Expression in Human Oral Epithelial Tumor Cells

Abstract

In our previous work, we have reported the expression of immunoglobulin (Ig) molecules by numerous epithelial cancer cells and hyperplastic epithelial cells. In the present study, we extended our investigation to study the frequencies of expression of IgG and IgA in some types of oral epithelial tumor cells, and analyzed the oral tumor-derived V regions characteristic of Ig gamma chain gene transcripts by immunohistochemistry, in situ hybridization, laser capture microdissection-correlated reverse-transcription polymerase chain reaction, and sequencing. IgG and IgA immunoreactivity was prominent in the cytoplasmic or plasma membrane or secretion of malignant cells, pleomorphic adenoma tumor cells, and some normal glandular epithelial cells or squamous cells adjacent to tumors. More importantly, rearranged Ig gene transcripts were identified in these tumor cells, and in some normal glandular epithelial cells, the V-D-J region sequences revealed that IgG transcripts in 2 tested oral tumors were oligoclonal. These results support that the phenomenon of Ig could also be expressed in oral cavity epithelial tumor cells.

Promotion of cell proliferation and inhibition of ADCC by cancerous immunoglobulin expressed in cancer cell lines

“…The unexpected finding that epithelial-derived cancer cells express and secrete several types of Ig has been confirmed by many laboratories; [3][4][5][6][7][8][9][10] 16,17 Although the structure of cancerous Ig is not clear, native western blot analysis of cell lysates from cancer cell lines showed that cancerous Ig contains abnormal Ig heavy chain and kappa light chain. Together with our previous finding that the Tx gene lacks the variable region of the Ig gene, these data suggest that cancerous Ig is likely very different from regular Ig and raise the question of whether cancerous Ig inhibits human humoral immunity.…”

“…2 Accumulating evidence has recently revealed that epithelial cancer cells and cancer tissues express 'Ig-like' molecules, such as the Ig kappa light chain, as well as Ig heavy chains, including a, c and m, in both cytoplasmic and secreted forms. [3][4][5][6][7][8][9][10] In our previous studies addressing the significance of cancerous Ig expression, we found that depletion of tumor-derived Ig by either antisense RNA or a human IgG or IgA antibody resulted in an increase in apoptosis and inhibition of cancer cell growth in vitro and in vivo. 3,11 Moreover, we extended our findings by using in situ hybridization to detect Ig kappa light chain expression in clinical cervical tissue samples, including cervicitis, dysplasia and cancer samples.…”

Roles of antigen receptors and CA215 in the innate immunity of cancer cells

“…Immunoglobulins expressed by cancer cells were initially reported more than a decade ago [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. By use of nested reverse transcription polymerase chain reaction (RT-PCR) on a single cell, it was first observed that the genes of antigen receptors, including those of immunoglobulins and T cell receptors (TCRs), were expressed among several different cancer cell lines [1,3,5,6,13].…”

Rearrangement and expression of the immunoglobulin μ-chain gene in human myeloid cells

“…Although it was once presumed that B lymphocytes and plasma cells are the only sources of Ig, it has been recently reported that Ig is expressed in many types of neoplastic epithelial cells [1][2][3][4][5][6] and several types of non-hematopoietic cells from healthy individuals. [7][8][9] Moreover, non-hematopoietic cell-derived Ig shares some interesting features, including the restricted or biased usage of certain sequences, 9,10 a unique glycosylation profile 11,12 and novel regulatory mechanisms of gene expression.…”