Icantly increased in the cytoplasm of cells from penile squamous cell carcinoma with high-risk HPVs independently of the subtype compared to HPV-negative penile squamous cell carcinoma (p,0.0001, Tukey’s post hoc test) (Figure 2B, C and H). Immunoreactivity for p16 was not detected or presented a weak expression in the nuclei of the non-neoplastic epithelia (control group) (Figure 2D) and increased immunoreactivity was observed in the nuclei of penile squamous cell carcinoma Title Loaded From File samples negative for HPV (p,0.0001, Tukey’s post hoc test) (Figure 2E and I) compared to non-neoplastic epithelia. Lowrisk HPV positive penile squamous cell carcinoma samples showed decreased expression of p16 compared to the high-risk HPV penile squamous cell carcinoma samples (data not shown for Title Loaded From File low-risk HPV positive samples and they were not included in the statistical analysis due to the small number). The penile squamous cell carcinoma samples with high-risk HPVs showed increased p16 expression observed both in the nuclei and in the cytoplasm indenpendently of the subtype (p,0.0001, Tukey’s post hoc test) (Figure 2F and I) relative to penile squamous cell carcinoma without 25331948 HPV. Negative control reactions were used for ANXA1 and p16 immunostaining (Figure 2G). ANXA1 and p16 immunodetection showed no significant difference between histological subtypes of penile squamous cell carcinoma since the most prevalent subtype was usual carcinoma (83 ).DiscussionSubtype Usual Verrucous Warty Sarcomatoid Papillary Total 3 1 18 1 1 24 11 3 16 14 2 1 35 and 11 16 and 11 Negative 1 1 20 2 1 1 Total 39 4 2 1 1doi:10.1371/journal.pone.0053260.tOverexpression of ANXA1 mRNA and Annexin-I (ANXA1) protein were detected in squamous cell carcinoma of penis. ANXA1 was the first member characterized of the annexin superfamily, characterized by the calcium-dependent ability to bind phospholipids. ANXA1 inhibits the activity of cytosolic phospholipase A2 (cPLA2) and cyclooxygenase-2 (COX-2), thus exhibiting anti-inflammatory, anti-pyretic and anti-hyperalgesic activities [27,28]. In addition, ANXA1 is associated with various physiological processes including cellular differentiation [29], cell proliferation and signal transduction [30,31]. Furthermore, deANXA1 Overexpression in HPV Positive Penis CancerFigure 2. Immunolocalization of annexin A1 (ANXA1) and p16 in human primary penile squamous cell carcinoma and histologically normal tumor margins. ANXA1 immunostaining in A) Histologically normal tumor margins; B) Human primary penile squamous cell carcinoma HPV-negative; C) Human primary penile squamous cell carcinoma positive for high-risk HPV. p16 immunostaining in D) Histologically normal tumor margins; E) Human primary penile squamous cell carcinoma HPV-negative; F) Human primary penile squamous cell carcinoma positive for high-risk HPV. G) Reaction control for ANXA1. H) Graphic of densitometry of the immunostaining of ANXA1 in the samples analyzed. I) Graphic of densitometry of the immunoistaining of p16 in the samples analyzed. Bars = 50 mm. (** = p,0.01; **** = p,0.0001; = p,0.0001, Tukey’s post hoc test). doi:10.1371/journal.pone.0053260.gregulation of ANXA1 has been correlated with tumor progression in several types of cancer [16,17,32?9]. One study suggested that ANXA1 appears to be induced in tumor endothelium, and the lack of ANXA1 in ANXA1-KO mice may impair tumor-induced angiogenesis with reduced blood supply explaining retarded tumor growth and metastasis in Lewis Lun.Icantly increased in the cytoplasm of cells from penile squamous cell carcinoma with high-risk HPVs independently of the subtype compared to HPV-negative penile squamous cell carcinoma (p,0.0001, Tukey’s post hoc test) (Figure 2B, C and H). Immunoreactivity for p16 was not detected or presented a weak expression in the nuclei of the non-neoplastic epithelia (control group) (Figure 2D) and increased immunoreactivity was observed in the nuclei of penile squamous cell carcinoma samples negative for HPV (p,0.0001, Tukey’s post hoc test) (Figure 2E and I) compared to non-neoplastic epithelia. Lowrisk HPV positive penile squamous cell carcinoma samples showed decreased expression of p16 compared to the high-risk HPV penile squamous cell carcinoma samples (data not shown for low-risk HPV positive samples and they were not included in the statistical analysis due to the small number). The penile squamous cell carcinoma samples with high-risk HPVs showed increased p16 expression observed both in the nuclei and in the cytoplasm indenpendently of the subtype (p,0.0001, Tukey’s post hoc test) (Figure 2F and I) relative to penile squamous cell carcinoma without 25331948 HPV. Negative control reactions were used for ANXA1 and p16 immunostaining (Figure 2G). ANXA1 and p16 immunodetection showed no significant difference between histological subtypes of penile squamous cell carcinoma since the most prevalent subtype was usual carcinoma (83 ).DiscussionSubtype Usual Verrucous Warty Sarcomatoid Papillary Total 3 1 18 1 1 24 11 3 16 14 2 1 35 and 11 16 and 11 Negative 1 1 20 2 1 1 Total 39 4 2 1 1doi:10.1371/journal.pone.0053260.tOverexpression of ANXA1 mRNA and Annexin-I (ANXA1) protein were detected in squamous cell carcinoma of penis. ANXA1 was the first member characterized of the annexin superfamily, characterized by the calcium-dependent ability to bind phospholipids. ANXA1 inhibits the activity of cytosolic phospholipase A2 (cPLA2) and cyclooxygenase-2 (COX-2), thus exhibiting anti-inflammatory, anti-pyretic and anti-hyperalgesic activities [27,28]. In addition, ANXA1 is associated with various physiological processes including cellular differentiation [29], cell proliferation and signal transduction [30,31]. Furthermore, deANXA1 Overexpression in HPV Positive Penis CancerFigure 2. Immunolocalization of annexin A1 (ANXA1) and p16 in human primary penile squamous cell carcinoma and histologically normal tumor margins. ANXA1 immunostaining in A) Histologically normal tumor margins; B) Human primary penile squamous cell carcinoma HPV-negative; C) Human primary penile squamous cell carcinoma positive for high-risk HPV. p16 immunostaining in D) Histologically normal tumor margins; E) Human primary penile squamous cell carcinoma HPV-negative; F) Human primary penile squamous cell carcinoma positive for high-risk HPV. G) Reaction control for ANXA1. H) Graphic of densitometry of the immunostaining of ANXA1 in the samples analyzed. I) Graphic of densitometry of the immunoistaining of p16 in the samples analyzed. Bars = 50 mm. (** = p,0.01; **** = p,0.0001; = p,0.0001, Tukey’s post hoc test). doi:10.1371/journal.pone.0053260.gregulation of ANXA1 has been correlated with tumor progression in several types of cancer [16,17,32?9]. One study suggested that ANXA1 appears to be induced in tumor endothelium, and the lack of ANXA1 in ANXA1-KO mice may impair tumor-induced angiogenesis with reduced blood supply explaining retarded tumor growth and metastasis in Lewis Lun.