Immunoglobulin G Expression in Lung Cancer and Its Effects on Metastasis

Abstract

Lung cancer is one of the leading malignancies worldwide, but the regulatory mechanism of its growth and metastasis is still poorly understood. We investigated the possible expression of immunoglobulin G (IgG) genes in squamous cell carcinomas and adenocarcinomas of the lung and related cancer cell lines. Abundant mRNA of IgG and essential enzymes for IgG synthesis, recombination activation genes 1, 2 (RAG1, 2) and activation-induced cytidine deaminase (AID) were detected in the cancer cells but not in adjacent normal lung tissue or normal lung epithelial cell line. The extents of IgG expression in 86 lung cancers were found to associate with clinical stage, pathological grade and lymph node metastasis. We found that knockdown of IgG with siRNA resulted in decreases of cellular proliferation, migration and attachment for cultured lung cancer cells. Metastasis-associated gene 1 (MTA1) appeared to be co-expressed with IgG in lung cancer cells. Statistical analysis showed that the rate of IgG expression was significantly correlated to that of MTA1 and to lymph node metastases. Inhibition of MTA1 gene expression with siRNA also led to decreases of cellular migration and attachment for cultured lung cancer cells. These evidences suggested that inhibition of cancer migration and attachment induced by IgG down-regulation might be achieved through MTA1 regulatory pathway. Our findings suggest that lung cancer-produced IgG is likely to play an important role in cancer growth and metastasis with significant clinical implications.

Comparative Proteomic Analysis of Breast Cancer Tissue and the Adjacent Normal Tissue in Iranian Patients with HER2 Negative Ductal Carcinoma of Breast

“…In addition, overexpression of constant regions of Ig gamma-2 and Ig mu chains in breast cancer has been recently documented by Cho et al (28). More recently, it has been reported that carcinomas and other cancer cells produce IgG (29) that contributes to cell proliferation, progression (30) and metastasis (31). In the present study, the expression of constant region of Ig gamma-1 and Ig kappa chains increased in the cancer tissue compared to the adjacent normal tissue, which is in agreement with the findings of Cho et al (28).…”

Novel Potential Biomarkers for Opisthorchis viverrini Infection and Associated Cholangiocarcinoma

“…Studies showed an association between Ig and other cancer types. IgG produced in lung cancer is believed to play a key role in cancer growth and metastasis, with significant clinical implications (39). IgA, IgE and IgG have been reported in serum and bile samples of patients with opisthorchiasis (40).…”

Cancerous Immunoglobulins in Cancer Immunology

“…By using IHC, flow cytometry, and/or indirect immunofluorescent assays, RP215 can be utilized as a diagnostic tool in determining proliferation, migration, and metastasis of cancer cells in cancerous tissues and in identifying cancer stem cells [49].…”