Dataset Information

Immunoglobulin gene transcripts have distinct VHDJH recombination characteristics in human epithelial cancer cells.

ABSTRACT: It was well accepted that only B-lymphocytes and plasma cells expressed immunoglobulin (Ig) gene. However, our group and others have confirmed that non-B-cells, such as epithelial cancer cells, can also express Ig. The aim of this work is to elucidate the role of non-B-cell-derived Ig by investigating the characteristics of the Ig heavy chain (IgH) gene repertoire in epithelial cancer cells. We cloned and sequenced 89 V(H)DJ(H) (V-D-J recombination of the IgH variable region) transcripts by microdissecting cells from eight different types of epithelial cancers and two cancer cell lines (HT-29 and HeLa S3). The cancer-derived Ig gene repertoire showed specific restricted patterns of V(H)DJ(H) recombination with seven sets of predominant V(H)DJ(H) sequences. Surprisingly, within a set of V(H)DJ(H) recombination, the variable (V) sequences derived from different cancer types had not only identical heavy chain variable (VH), diversity (D), and joining (JH) segments usage, but also identical junctions and mutation targets in the V(H) region. The V(Hgamma)DJ(Hgamma) (but not V(Hmicro)DJ(Hmicro)) in the cancer-derived sequences had a high mutation rate; however, it was shown that the mechanism of hypermutation was different from antigen selection in B-cell-derived V(Hgamma)DJ(Hgamma)sequences. In contrast to V(Hmicro)DJ(Hmicro), the V(Hgamma)DJ(Hgamma) sequences did not appear to originate from classical class switching. These results suggest that cancer-derived Ig genes have a distinct repertoire that may have implications for their role in carcinogenesis.

SUBMITTER: Zheng J

PROVIDER: S-EPMC2679462 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Immunoglobulin gene transcripts have distinct VHDJH recombination characteristics in human epithelial cancer cells.

Zheng Jie J Huang Jing J Mao Yuntao Y Liu Shiqing S Sun Xin X Zhu Xiaohui X Ma Teng T Zhang Li L Ji Jiafu J Zhang Youhui Y Yin C Cameron CC Qiu Xiaoyan X

The Journal of biological chemistry 20090316 20

It was well accepted that only B-lymphocytes and plasma cells expressed immunoglobulin (Ig) gene. However, our group and others have confirmed that non-B-cells, such as epithelial cancer cells, can also express Ig. The aim of this work is to elucidate the role of non-B-cell-derived Ig by investigating the characteristics of the Ig heavy chain (IgH) gene repertoire in epithelial cancer cells. We cloned and sequenced 89 V(H)DJ(H) (V-D-J recombination of the IgH variable region) transcripts by micr ...[more]

PMID: 19293154

Similar Datasets

Project description:BackgroundThe serine-threonine kinase AKT1 plays essential roles during normal mammary gland development as well as the initiation and progression of breast cancer. AKT1 is generally considered a ubiquitously expressed gene, and its persistent activation is transcriptionally controlled by regulatory elements characteristic of housekeeping gene promoters. We recently identified a novel Akt1 transcript in mice (Akt1m), which is induced by growth factors and their signal transducers of transcription from a previously unknown promoter. The purpose of this study was to examine whether normal and neoplastic human breast epithelial cells express an orthologous AKT1m transcript and whether its expression is deregulated in cancer cells.MethodsInitial sequence analyses were performed using the UCSC Genome Browser and GenBank to assess the potential occurrence of an AKT1m transcript variant in human cells and to identify conserved promoter sequences that are orthologous to the murine Akt1m. Quantitative RT-PCR was used to determine the transcriptional activation of AKT1m in mouse mammary tumors as well as 41 normal and neoplastic human breast epithelial cell lines and selected primary breast cancers.ResultsWe identified four new AKT1 transcript variants in human breast cancer cells that are orthologous to the murine Akt1m and that encode the full-length kinase. These transcripts originate from an alternative promoter that is conserved between humans and mice. Akt1m is upregulated in the majority of luminal-type and basal-type mammary cancers in four different genetically engineered mouse models. Similarly, a subset of human breast cancer cell lines and primary breast cancers exhibited a higher expression of orthologous AKT1m transcripts.ConclusionsThe existence of an alternative promoter that drives the expression of the unique AKT1m transcript may provide a mechanism by which the levels of AKT1 can be temporally and spatially regulated at particular physiological states, such as cancer, where a heightened activity of this kinase is required.

Project description:BackgroundSpontaneous immortalisation of cultured mammary epithelial cells (MECs) is an extremely rare event, and the molecular mechanism behind spontaneous immortalisation of MECs is unclear. Here, we report the establishment of a spontaneously immortalised bovine mammary epithelial cell line (BME65Cs) and the changes in gene expression associated with BME65Cs cells.ResultsBME65Cs cells maintain the general characteristics of normal mammary epithelial cells in morphology, karyotype and immunohistochemistry, and are accompanied by the activation of endogenous bTERT (bovine Telomerase Reverse Transcriptase) and stabilisation of the telomere. Currently, BME65Cs cells have been passed for more than 220 generations, and these cells exhibit non-malignant transformation. The expression of multiple genes was investigated in BME65Cs cells, senescent BMECs (bovine MECs) cells, early passage BMECs cells and MCF-7 cells (a human breast cancer cell line). In comparison with early passage BMECs cells, the expression of senescence-relevant apoptosis-related gene were significantly changed in BME65Cs cells. P16INK4a was downregulated, p53 was low expressed and Bax/Bcl-2 ratio was reversed. Moreover, a slight upregulation of the oncogene c-Myc, along with an undetectable level of breast tumor-related gene Bag-1 and TRPS-1, was observed in BME65Cs cells while these genes are all highly expressed in MCF-7. In addition, DNMT1 is upregulated in BME65Cs. These results suggest that the inhibition of both senescence and mitochondrial apoptosis signalling pathways contribute to the immortality of BME65Cs cells. The expression of p53 and p16INK4a in BME65Cs was altered in the pattern of down-regulation but not "loss", suggesting that this spontaneous immortalization is possibly initiated by other mechanism rather than gene mutation of p53 or p16INK4a.ConclusionsSpontaneously immortalised BME65Cs cells maintain many characteristics of normal BMEC cells and exhibit non-malignant transformation. Although this cell line displays altered patterns of gene expression, it is clearly distinct from malignant breast cancer cell line. It showed that co-inhibition of cellular senescence and mitochondrial apoptosis pathways coordinates BME65Cs cells immortalisation. Additionally, mechanisms other than gene mutation are likely to be involved in regulation of cellular functions. This study provides an insight into the relationship between cell senescence and immortalisation. BME65Cs cells will be useful in future studies of cellular senescence and tumorigenesis.

Dataset Information

Immunoglobulin gene transcripts have distinct VHDJH recombination characteristics in human epithelial cancer cells.

Publications

Immunoglobulin gene transcripts have distinct VHDJH recombination characteristics in human epithelial cancer cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets