title: Increased levels of sperm protein 17 mRNA and circulating antibodies in periampullary carcinoma patients.
abstract: BACKGROUND
  Present-day diagnostic modalities for detecting periampullary carcinoma are suboptimal, and currently used proven markers lack specificity and sensitivity.
  
  
  METHODS
  In order to assess the diagnostic potential of sperm protein 17, a cancer testis antigen, quantitative real-time PCR was performed to evaluate the expression of sperm protein 17 in tissue and sera specimens collected from periampullary carcinoma patients and normal subjects. Additionally, circulating levels of anti-sperm protein 17 antibodies were determined in sera of periampullary carcinoma patients and normal subjects using ELISA.
  
  
  RESULTS
  Aberrant expression of sperm protein 17 was found in 14/15 (93 %) periampullary cancer tissues when compared with distant matched nonmalignant tissues (P = 0.006, Mann-Whitney U test). None of the distant matched nonmalignant tissues showed increased expression of sperm protein 17 mRNA. Area under the curve, sensitivity, and specificity were 0.791, 87, and 73 %, respectively. Increased levels of sperm protein 17 mRNA were demonstrated in sera of periampullary carcinoma patients (P = 0.020, Student's t test). Circulating levels of anti-sperm protein 17 antibody were found to be significantly elevated in 27/30 (90 %) periampullary carcinoma patients (P < 0.001, Student's t test). Area under the curve, sensitivity, and specificity were 0.954, 86.7, and 96.3 %, respectively. Only two of the normal subjects (7 %) showed elevated levels of anti-sperm protein 17 antibody.
  
  
  CONCLUSIONS
  For the first time, our findings suggest that high levels of sperm protein 17 mRNA as well as increased circulating anti-sperm protein 17 antibodies can be used to distinguish periampullary cancer patients from healthy individuals, highlighting the diagnostic potential of sperm protein 17.
authors.affiliation: University School of Biotechnology, Guru Gobind Singh Indraprastha University, Sector-16(c), Dwarka, New Delhi, 110078, India.
authors.forename: Shivam
authors.initials: S
authors.lastname: Singh
authors.forename: Anoop
authors.initials: A
authors.lastname: Saraya
authors.forename: Rinu
authors.initials: R
authors.lastname: Sharma
mesh_terms: D014670:Ampulla of Vater; D000951:Antigens, Neoplasm / Q000097:blood; D000954:Antigens, Surface / Q000096:biosynthesis*; D001323:Autoantibodies / Q000097:blood; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins / Q000096:biosynthesis*; D003135:Common Bile Duct / Q000737:chemistry / Q000276:immunology; D003138:Common Bile Duct Neoplasms / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008297:Male; D008565:Membrane Proteins; D012333:RNA, Messenger
chemical_list: D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D001323:Autoantibodies; D014408:Biomarkers, Tumor; D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; C090172:SPA17 protein, human