title: Best practice for PTEN gene and protein assessment in anatomic pathology.
abstract: There is a lack of standardization of a best practice protocol for Phosphatase and Tensin Homolog (PTEN) assessment by immunohistochemistry in anatomic pathology routine practice. We performed immunohistochemistry for 19 antibodies against PTEN, eleven of which were excluded during the standardization step. Immunohistochemistry of the remaining eight antibodies was performed on a Tissue Microarray containing 55 prostate and 40 renal carcinoma samples. Fluorescent in situ hybridization (FISH) was used as reference standard for immunohistochemistry specificity evaluation. Concerning nuclear staining, polyclonal (Cat#22034-1-AP); 6H2.1 mMAb (Cat#ABM-2052), Y184 RabMAb (Cat#NB110-57441) and 217702 mMAb antibodies presented the highest agreement with fluorescent in situ hybridization (p<0.001 for all) and with regard to cytoplasmic staining, Y184 RabMAb (Cat#NB110-57441); polyclonal (Cat#22034-1-AP) and 217702 mMAb presented the highest agreement (p<0.001 for all). Our results indicate that several commercially available antibodies do not show reliability of sensitivity and specificity for PTEN evaluation and we propose 6H2.1 mMAb (Cat#ABM-2052) as the antibody of choice for laboratory standardization and best practice in clinical routine, which demonstrated excellent sensitivity for both nuclear and cytoplasmic staining, specificity for PTEN by Western blot and good correlation with PTEN status by FISH with regard to nuclear staining.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medicine of Sao Paulo University, Sao Paulo, SP, Brazil.
authors.forename: Kátia C
authors.initials: KC
authors.lastname: Carvalho
authors.affiliation: Research Center, Antonio Prudente Foundation, Hospital A.C. Camargo, Sao Paulo, SP, Brazil.
authors.forename: Beatriz M
authors.initials: BM
authors.lastname: Maia
authors.affiliation: Research Center, Antonio Prudente Foundation, Hospital A.C. Camargo, Sao Paulo, SP, Brazil.
authors.forename: Samantha V
authors.initials: SV
authors.lastname: Omae
authors.affiliation: Department of Microbiology, Immunology and Parasitology, UNIFESP, Sao Paulo, Brazil.
authors.forename: Antonio A
authors.initials: AA
authors.lastname: Rocha
authors.affiliation: Department of Anatomic Pathology, Hospital A.C. Camargo, Sao Paulo, SP, Brazil.
authors.forename: Luiz P
authors.initials: LP
authors.lastname: Covizzi
authors.affiliation: Department of Anatomic Pathology, Hospital A.C. Camargo, Sao Paulo, SP, Brazil.
authors.forename: José
authors.initials: J
authors.lastname: Vassallo
authors.affiliation: Research Center, Antonio Prudente Foundation, Hospital A.C. Camargo, Sao Paulo, SP, Brazil; Department of Anatomic Pathology, Hospital A.C. Camargo, Sao Paulo, SP, Brazil. Electronic address: rafael.malagoli@gmail.com.
authors.forename: Rafael M
authors.initials: RM
authors.lastname: Rocha
authors.affiliation: Research Center, Antonio Prudente Foundation, Hospital A.C. Camargo, Sao Paulo, SP, Brazil; Department of Anatomic Pathology, Hospital A.C. Camargo, Sao Paulo, SP, Brazil.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Soares
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000592:standards; D017404:In Situ Hybridization, Fluorescence; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051059:PTEN Phosphohydrolase / Q000235:genetics* / Q000378:metabolism; D017410:Practice Guidelines as Topic; D011467:Prostate / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D012015:Reference Standards; D046888:Tissue Array Analysis
chemical_list: D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: Fluorescent in situ hybridization; Human; Immunohistochemistry; PTEN; Prostatic neoplasm; Renal cell carcinoma