BACKGROUND There is growing evidence proving that many human carcinomas, including colon cancer, can overexpress immunoglobulin(Ig);the non B cancer cell-derived Ig usually displayed unique V(D)J rearrangement pattern that are distinct from B cell-derived Ig. Especially, the cancer-derived Ig plays important roles in cancer initiation, progression, and metastasis. However, it still remains unclear if the colon cancer-derived Ig can display unique V(D)J pattern and sequencing, which can be used as novel target for colon cancer therapy.AIM To investigate the Ig repertoire features expressed in human colon cancer cells.METHODS Seven cancerous tissue samples of colon adenocarcinoma and corresponding noncancerous tissue samples were sorted by fluorescence-activated cell sorting using epithelial cell adhesion molecule as a marker for epithelial cells. Ig repertoire sequencing was used to analyze the expression profiles of all 5 classes of Ig heavy chains(IgH) and the Ig repertoire in colon cancer cells and corresponding normal epithelial cells.RESULTS We found that all 5 IgH classes can be expressed in both colon cancer cells and normal epithelial cells. Surprisingly, unlike the normal colonic epithelial cells that expressed 5 Ig classes, our results suggested that cancer cells most prominently express IgG. Next, we found that the usage of Ig in cancer cells caused the expression of some unique Ig repertoires compared to normal cells. Some VH segments, such as VH3-7, have been used in cancer cells, and VH3-74 was frequently present in normal epithelial cells. Moreover, compared to the normal cell-derived Ig, most cancer cell-derived Ig showed unique VHDJH patterns.Importantly, even if the same VHDJH pattern was seen in cancer cells and normal cells, cancer cell-derived IgH always displayed distinct hypermutation hot points.CONCLUSION We found that colon cancer cells could frequently express IgG and unique IgH repertoires, which may be involved in carcinogenesis of colon cancer. The unique IgH repertoire has the potenti
Key support projects of the National Natural Science Foundation’s major research program,No.91642206
Major international cooperation projects of the National Natural Science Foundation,No.81320108020
Beijing Natural Science Foundation,No.7182171
Research institute fund of NHC Key Laboratory of Medical Immunology,Peking University,No.BMU2018JDJS010
Nonprofit central research institute fund of Chinese Academy of Medical Sciences,No.2018PT31039.
Corresponding author:Xiao-Yan Qiu,MD,PhD,Doctor,Department of Immunology,School of Basic Medical Sciences,Peking University Health Science Center,Xueyuan Road,Beijing 100191,China.email@example.com,Telephone:+86-10-82805477,Fax:+86-10-82801149.