1. Volume 133, Issue 3, Pages 853-861 (September 2007)
A Novel Secretin Receptor Splice Variant Potentially Useful for Early Diagnosis of Pancreatic Carcinoma 
Gregory M. Hayes, Patricia E. Carrigan, Maoqing Dong, Jean–Claude Reubi, Laurence J. Miller 
Gastroenterology 
Volume 133, Issue 3, Pages (September 2007)
DOI: /j.gastro
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2. Figure 1
Expression of secretin receptor spliceoforms in human pancreatic tumor cell lines and pancreatic and liver tissues. Nested RT-PCR reactions were used to amplify the portion of human secretin transcripts between exons 2 and 5 among a panel of pancreatic tumor cell lines (left), matched healthy pancreatic tissue (n) and malignant pancreatic carcinomas (t) (middle), and benign and malignant liver tissue (right). Representative amplicons were excised and sequenced to confirm the identity of wild-type encoding secretin receptor, a splice variant exhibiting loss of exon 3, and a novel splice variant exhibiting a loss of exons 3 and 4 from the processed transcripts. RT-PCR reactions for actin were used to normalize levels of expression. Data are representative of 3 independent experiments.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

3. Figure 2
Sequence of the novel hSecR(Δexon 3,4) spliceoform. The nucleotide sequence of hSecR(Δexon 3,4) is illustrated along with the location of each exon-exon splice junction. The predicted amino acid sequence encoded by this transcript is indicated where the first 21 residues (−21 to −1) represent the leader sequence (dashed line beneath), and residues 44 to 111 represent the novel peptide sequence resulting from the change in reading frame downstream of the exon 2/5 junction. The locations of the 2 antigenic peptides used for generating the monoclonal antibodies are underlined and labeled.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

4. Figure 3
Confirmation of hSecR(Δexon 3,4) antibody specificity and application to demonstrate secretion from pancreatic cancer cells. Both the 5G1 and 8F4 mAbs were incubated with each of the radioiodinated forms of the antigenic peptides used to immunize mice, and antibody-peptide complexes were precipitated with protein A/G agarose beads to determine mAb specificity (A). The ability of both 5G1 and 8F4 Abs to recognize the full length hSecR(Δexon 3,4) protein was also determined by Western blot analysis (B) utilizing lysates produced from cells transfected with the HA-tagged hSecR(Δexon 3,4) pCEP4 construct. As a positive control, a Western blot was also performed using an anti-HA antibody. In panel C, MiaPaCa2 cells were transfected with the HA-tagged hSecR(Δexon 3,4) pCEP4 construct or the pCEP4 vector only, and medium was replaced after 24 hours. Medium was removed from the cells 48 hours after transfection and was concentrated using a 10-kilodalton cut-off centricon column. Supernatants were run on Western blots, and detection of HA-tagged hSecR(Δexon 3,4) protein present in the medium was performed with both the 5G1 and anti-HA (control) mAbs (C). Data are representative of 2 independent experiments.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions

5. Figure 4
Results of the sandwich ELISA for measurement of the hSecR(Δexon 3,4) protein in serum samples. Shown are measured values from individual patients and controls (as described in Table 1), with those below the limit of sensitivity of the assay charted at that limit of 100 pmol/L.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2007 AGA Institute Terms and Conditions