Phenotypic analysis of mice lacking the Tmprss2-encoded protease

Area of Science:

• Biochemistry
• Genetics
• Molecular Biology

Background:

• TMPRSS2 (Transmembrane protease, serine 2) is an androgen-regulated enzyme crucial in prostate epithelium.
• Its role in prostate carcinogenesis is suspected, but in vivo functions remain largely unknown.
• Protease-activated receptor 2 is a potential substrate, but biological activity requires in vivo validation.

Purpose of the Study:

• To investigate the in vivo biological functions of TMPRSS2.
• To determine the necessity of TMPRSS2's serine protease activity for normal prostate function and development.
• To assess the impact of TMPRSS2 deficiency on prostate carcinogenesis and fertility.

Main Methods:

• Generation of Tmprss2-/- mice via homologous recombination, targeting the serine protease domain.
• Phenotypic analysis of knockout mice, including survival, fertility, prostatic secretion analysis, organ histology, and cell regrowth post-castration.
• Assessment of transcriptional compensation by related Tmprss2 homologs.

Main Results:

• Tmprss2-/- mice exhibited normal development, survival, and fertility compared to wild-type littermates.
• No discernible abnormalities in prostate histology, function, or luminal epithelial cell regrowth were observed.
• Prostatic secretion protein levels remained unchanged, and no increased incidence of hyperplasia or carcinoma was noted.
• Transcriptional compensation by homologous genes was ruled out as a cause for the lack of phenotype.

Conclusions:

• The absence of a phenotype in Tmprss2-/- mice suggests functional redundancy within the serine protease family.
• TMPRSS2 may perform specialized, non-essential functions revealed only under specific stress or disease conditions.
• Further research is needed to elucidate the precise role of TMPRSS2 in prostate health and disease.