Trefoil factor 1 is a protein that in humans is encoded by the TFF1 gene (also called pS2 gene). Members of the trefoil family are characterized by having at least one copy of the trefoil motif, a 40-amino acid domain that contains three conserved disulfides. They are stable secretory proteins expressed in gastrointestinal mucosa. Their functions are not defined, but they may protect the mucosa from insults, stabilize the mucus layer, and affect healing of the epithelium. This gene, which is expressed in the gastric mucosa, has also been studied because of its expression in human tumors. This gene and two other related trefoil family member genes are found in a cluster on chromosome 21.
Background References
1. Wu CS et al. Aberrant JAK/STAT Signaling Suppresses TFF1 and TFF2 through Epigenetic Silencing of GATA6 in Gastric Cancer. Int J Mol Sci 17:(9) (2016).
2. Liau JY et al. Morphological subclassification of intrahepatic cholangiocarcinoma: etiological, clinicopathological, and molecular features. Mod Pathol 27(8):1163-73 (2014).
Tissue Specificity
Found in stomach, with highest levels in the upper gastric mucosal cells (at protein level). Detected in goblet cells of the small and large intestine and rectum, small submucosal glands in the esophagus, mucous acini of the sublingual gland, submucosal glands of the trachea, and epithelial cells lining the exocrine pancreatic ducts but not in the remainder of the pancreas (at protein level). Scattered expression is detected in the epithelial cells of the gallbladder and submucosal glands of the vagina, and weak expression is observed in the bronchial goblet cells of the pseudostratified epithelia in the respiratory system (at protein level). Detected in urine (at protein level). Strongly expressed in breast cancer but at low levels in normal mammary tissue. It is regulated by estrogen in MCF-7 cells. Strong expression found in normal gastric mucosa and in the regenerative tissues surrounding ulcerous lesions of gastrointestinal tract, but lower expression found in gastric cancer (at protein level).
Western blot analysis of Estrogen Inducible Protein pS2 on different lysates with Rabbit anti-Estrogen Inducible Protein pS2 antibody (ET1705-85) at 1/5,000 dilution.
Lane 1: MCF7 cell lysate (15 µg/Lane) Lane 2: MDA-MB-231 cell lysate (negative) (15 µg/Lane) Lane 3: Human liver tissue lysate (negative) (20 µg/Lane) Lane 4: Human kidney tissue lysate (negative) (20 µg/Lane)
Predicted band size: 9 kDa Observed band size: 9 kDa
Exposure time: 1 minute;
4-20% SDS-PAGE gel.
Proteins were transferred to a PVDF membrane and blocked with 5% NFDM/TBST for 1 hour at room temperature. The primary antibody (ET1705-85) at 1/5,000 dilution was used in 5% NFDM/TBST at 4℃ overnight. Goat Anti-Rabbit IgG - HRP Secondary Antibody (HA1001) at 1/50,000 dilution was used for 1 hour at room temperature.
☑ Relative expression (RE)
Immunocytochemistry analysis of MCF7 (positive) and MDA-MB-231 (negative) labeling Estrogen Inducible Protein pS2 with Rabbit anti-Estrogen Inducible Protein pS2 antibody (ET1705-85) at 1/100 dilution.
Cells were fixed in 4% paraformaldehyde for 15 minutes at room temperature, permeabilized with 0.1% Triton X-100 in PBS for 15 minutes at room temperature, then blocked with 1% BSA in 10% negative goat serum for 1 hour at room temperature. Cells were then incubated with Rabbit anti-Estrogen Inducible Protein pS2 antibody (ET1705-85) at 1/100 dilution in 1% BSA in PBST overnight at 4 ℃. Goat Anti-Rabbit IgG H&L (iFluor™ 488, HA1121) was used as the secondary antibody at 1/1,000 dilution. PBS instead of the primary antibody was used as the secondary antibody only control. Nuclear DNA was labelled in blue with DAPI.
Beta tubulin (M1305-2, red) was stained at 1/100 dilution overnight at +4℃. Goat Anti-Mouse IgG H&L (iFluor™ 594, HA1126) was used as the secondary antibody at 1/1,000 dilution.
Immunohistochemical analysis of paraffin-embedded human stomach tissue with Rabbit anti-Estrogen Inducible Protein pS2 antibody (ET1705-85) at 1/1,000 dilution.
The section was pre-treated using heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0) for 20 minutes. The tissues were blocked in 1% BSA for 20 minutes at room temperature, washed with ddH2O and PBS, and then probed with the primary antibody (ET1705-85) at 1/1,000 dilution for 1 hour at room temperature. The detection was performed using an HRP conjugated compact polymer system. DAB was used as the chromogen. Tissues were counterstained with hematoxylin and mounted with DPX.
Immunohistochemical analysis of paraffin-embedded human stomach carcinoma tissue with Rabbit anti-Estrogen Inducible Protein pS2 antibody (ET1705-85) at 1/1,000 dilution.
The section was pre-treated using heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0) for 20 minutes. The tissues were blocked in 1% BSA for 20 minutes at room temperature, washed with ddH2O and PBS, and then probed with the primary antibody (ET1705-85) at 1/1,000 dilution for 1 hour at room temperature. The detection was performed using an HRP conjugated compact polymer system. DAB was used as the chromogen. Tissues were counterstained with hematoxylin and mounted with DPX.
Immunohistochemical analysis of paraffin-embedded human breast carcinoma tissue with Rabbit anti-Estrogen Inducible Protein pS2 antibody (ET1705-85) at 1/1,000 dilution.
The section was pre-treated using heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0) for 20 minutes. The tissues were blocked in 1% BSA for 20 minutes at room temperature, washed with ddH2O and PBS, and then probed with the primary antibody (ET1705-85) at 1/1,000 dilution for 1 hour at room temperature. The detection was performed using an HRP conjugated compact polymer system. DAB was used as the chromogen. Tissues were counterstained with hematoxylin and mounted with DPX.
Immunohistochemical analysis of paraffin-embedded human pancreas tissue with Rabbit anti-Estrogen Inducible Protein pS2 antibody (ET1705-85) at 1/1,000 dilution.
The section was pre-treated using heat mediated antigen retrieval with Tris-EDTA buffer (pH 9.0) for 20 minutes. The tissues were blocked in 1% BSA for 20 minutes at room temperature, washed with ddH2O and PBS, and then probed with the primary antibody (ET1705-85) at 1/1,000 dilution for 1 hour at room temperature. The detection was performed using an HRP conjugated compact polymer system. DAB was used as the chromogen. Tissues were counterstained with hematoxylin and mounted with DPX.
☑ Relative expression (RE)
Flow cytometric analysis of MDA-MB-231 (left, negative) and MCF7 (right, positive) cells labeling Estrogen Inducible Protein pS2.
Cells were fixed and permeabilized. Then stained with the primary antibody (ET1705-85, 1/1,000) (red) compared with Rabbit IgG Isotype Control (green). After incubation of the primary antibody at +4℃ for an hour, the cells were stained with a iFluor™ 488 conjugate-Goat anti-Rabbit IgG Secondary antibody (HA1121) at 1/1,000 dilution for 30 minutes at +4℃. Unlabelled sample was used as a control (cells without incubation with primary antibody; black).
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