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Transcription factors E2A, FOXO1 and FOXP1 regulate recombination activating gene expression in cancer cells.

Chen Z, Xiao Y, Zhang J, Li J, Liu Y, Zhao Y, Ma C, Luo J, Qiu Y, Huang G, Korteweg C, Gu J - PLoS ONE (2011)

Bottom Line: It has long been accepted that immunoglobulins (Igs) were produced by B lymphoid cells only.Chromatin immunoprecipitation experiments showed acetylation of RAG enhancer (Erag) and E2A, FOXO1 or FOXP1 were bound to Erag in vivo.These results indicate that in these cancer cells the transcription factors E2A, FOXO1 and FOXP1 regulate RAG expression, which initiates Ig gene rearrangement much in the way similar to B lymphocytes.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Shantou University Medical College, Shantou, China.

ABSTRACT
It has long been accepted that immunoglobulins (Igs) were produced by B lymphoid cells only. Recently Igs have been found to be expressed in various human cancer cells and promote tumor growth. Recombination activating gene 1 (RAG1) and RAG2, which are essential enzymes for initiating variable-diversity-joining segment recombination, have also been found to be expressed in cancer cells. However, the mechanism of RAG activation in these cancer cells has not been elucidated. Here, we investigated the regulatory mechanism of RAG expression in four human cancer cell lines by analyzing transcription factors that induce RAG activation in B cells. By RT-PCR, Western blot and immunofluorescence, we found that transcription factors E2A, FOXO1 and FOXP1 were expressed and localized to the nuclei of these cancer cells. Over-expression of E2A, FOXO1 or Foxp1 increased RAG expression, while RNA interference of E2A, FOXO1 or FOXP1 decreased RAG expression in the cancer cells. Chromatin immunoprecipitation experiments showed acetylation of RAG enhancer (Erag) and E2A, FOXO1 or FOXP1 were bound to Erag in vivo. These results indicate that in these cancer cells the transcription factors E2A, FOXO1 and FOXP1 regulate RAG expression, which initiates Ig gene rearrangement much in the way similar to B lymphocytes.

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Related in: MedlinePlus

Transient over-expression of E47, E12, FOXO1 or Foxp1A increased RAG expression in MCF-7 cells.MCF-7 cells were transfected with the empty vector or transcription factor expression vector pIRES2-EGFP-hE47, pIRES2-EGFP-hE12, pcDNA3-GFP-FOXO1;AAA or pCDNAI/NEO-5’HA-Foxp1A. 48 hours later total protein from MCF-7 cells was collected and analyzed by Western blot. GAPDH was shown as a loading control. Experiments were repeated three times with similar results. Similar results were obtained for the A549 cell line (data not shown).
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pone-0020475-g004: Transient over-expression of E47, E12, FOXO1 or Foxp1A increased RAG expression in MCF-7 cells.MCF-7 cells were transfected with the empty vector or transcription factor expression vector pIRES2-EGFP-hE47, pIRES2-EGFP-hE12, pcDNA3-GFP-FOXO1;AAA or pCDNAI/NEO-5’HA-Foxp1A. 48 hours later total protein from MCF-7 cells was collected and analyzed by Western blot. GAPDH was shown as a loading control. Experiments were repeated three times with similar results. Similar results were obtained for the A549 cell line (data not shown).

Mentions: To explore the effect of transcription factors E2A, FOXO1 and FOXP1 on RAG expression, A549 and MCF-7 cells were transfected with the expression vector for E47, E12, Foxp1A or FOXO1. The empty vector was used as a negative control. Forty-eight hours after transfection, total protein was extracted for analysis of E2A, FOXP1, FOXO1 and RAG expression by Western blot assay. The results showed that transfection with the expression vector for E47, E12, Foxp1A or FOXO1 increased both RAG1 and RAG2 expressions (Figure 4). This data indicate that over-expression of E2A, FOXO1 or Foxp1 up-regulated the expression of RAG1 and RAG2 in MCF-7 cells. Similar results were obtained using the A549 cell line (data not shown).


Transcription factors E2A, FOXO1 and FOXP1 regulate recombination activating gene expression in cancer cells.

Chen Z, Xiao Y, Zhang J, Li J, Liu Y, Zhao Y, Ma C, Luo J, Qiu Y, Huang G, Korteweg C, Gu J - PLoS ONE (2011)

Transient over-expression of E47, E12, FOXO1 or Foxp1A increased RAG expression in MCF-7 cells.MCF-7 cells were transfected with the empty vector or transcription factor expression vector pIRES2-EGFP-hE47, pIRES2-EGFP-hE12, pcDNA3-GFP-FOXO1;AAA or pCDNAI/NEO-5’HA-Foxp1A. 48 hours later total protein from MCF-7 cells was collected and analyzed by Western blot. GAPDH was shown as a loading control. Experiments were repeated three times with similar results. Similar results were obtained for the A549 cell line (data not shown).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3105062&req=5

pone-0020475-g004: Transient over-expression of E47, E12, FOXO1 or Foxp1A increased RAG expression in MCF-7 cells.MCF-7 cells were transfected with the empty vector or transcription factor expression vector pIRES2-EGFP-hE47, pIRES2-EGFP-hE12, pcDNA3-GFP-FOXO1;AAA or pCDNAI/NEO-5’HA-Foxp1A. 48 hours later total protein from MCF-7 cells was collected and analyzed by Western blot. GAPDH was shown as a loading control. Experiments were repeated three times with similar results. Similar results were obtained for the A549 cell line (data not shown).
Mentions: To explore the effect of transcription factors E2A, FOXO1 and FOXP1 on RAG expression, A549 and MCF-7 cells were transfected with the expression vector for E47, E12, Foxp1A or FOXO1. The empty vector was used as a negative control. Forty-eight hours after transfection, total protein was extracted for analysis of E2A, FOXP1, FOXO1 and RAG expression by Western blot assay. The results showed that transfection with the expression vector for E47, E12, Foxp1A or FOXO1 increased both RAG1 and RAG2 expressions (Figure 4). This data indicate that over-expression of E2A, FOXO1 or Foxp1 up-regulated the expression of RAG1 and RAG2 in MCF-7 cells. Similar results were obtained using the A549 cell line (data not shown).

Bottom Line: It has long been accepted that immunoglobulins (Igs) were produced by B lymphoid cells only.Chromatin immunoprecipitation experiments showed acetylation of RAG enhancer (Erag) and E2A, FOXO1 or FOXP1 were bound to Erag in vivo.These results indicate that in these cancer cells the transcription factors E2A, FOXO1 and FOXP1 regulate RAG expression, which initiates Ig gene rearrangement much in the way similar to B lymphocytes.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Shantou University Medical College, Shantou, China.

ABSTRACT
It has long been accepted that immunoglobulins (Igs) were produced by B lymphoid cells only. Recently Igs have been found to be expressed in various human cancer cells and promote tumor growth. Recombination activating gene 1 (RAG1) and RAG2, which are essential enzymes for initiating variable-diversity-joining segment recombination, have also been found to be expressed in cancer cells. However, the mechanism of RAG activation in these cancer cells has not been elucidated. Here, we investigated the regulatory mechanism of RAG expression in four human cancer cell lines by analyzing transcription factors that induce RAG activation in B cells. By RT-PCR, Western blot and immunofluorescence, we found that transcription factors E2A, FOXO1 and FOXP1 were expressed and localized to the nuclei of these cancer cells. Over-expression of E2A, FOXO1 or Foxp1 increased RAG expression, while RNA interference of E2A, FOXO1 or FOXP1 decreased RAG expression in the cancer cells. Chromatin immunoprecipitation experiments showed acetylation of RAG enhancer (Erag) and E2A, FOXO1 or FOXP1 were bound to Erag in vivo. These results indicate that in these cancer cells the transcription factors E2A, FOXO1 and FOXP1 regulate RAG expression, which initiates Ig gene rearrangement much in the way similar to B lymphocytes.

Show MeSH
Related in: MedlinePlus