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Napsin A Expression in Human Tumors and Normal Tissues.

Sören Weidemann1, Jan Lukas Böhle1, Hendrina Contreras1

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Pathology Oncology Research : POR
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Summary

Napsin A (TAO1/TAO2) is a proteinase expressed in lung adenocarcinoma, but also found in 15 other tumor types. Reduced expression in renal cell carcinomas correlates with poorer prognosis, indicating its role in tumor dedifferentiation.

Keywords:
diagnostichuman cancer typesimmunohistochemistrynapsin Atissue micro array

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Area of Science:

  • Biochemistry
  • Oncology
  • Pathology

Background:

  • Napsin A (TAO1/TAO2) is a pepsin family aspartic proteinase.
  • It plays roles in lung type II pneumocyte prosurfactant protein B maturation and renal cell lysosomal catabolism.
  • Napsin A is a biomarker for lung adenocarcinoma but can be expressed in other cancers.

Purpose of the Study:

  • To comprehensively map Napsin A expression across diverse normal and tumor tissues.
  • To identify and rank tumor types by Napsin A prevalence.
  • To investigate the correlation between Napsin A expression and clinic-pathological features in specific cancers.

Main Methods:

  • Immunohistochemistry on tissue microarrays.
  • Evaluation of 11,957 tumor samples (115 types/subtypes) and 500 normal tissue samples (76 types).

Main Results:

  • Napsin A expression detected in 16 distinct tumor types.
  • High prevalence observed in lung adenocarcinoma, ovarian clear cell adenocarcinoma, and endometrial clear cell adenocarcinoma.
  • Reduced Napsin A expression in renal cell carcinomas linked to adverse clinic-pathological features.

Conclusions:

  • A comprehensive ranking of tumor types based on Napsin A expression prevalence was established.
  • Loss of Napsin A expression is associated with tumor dedifferentiation in renal cell carcinomas.