OBJECTIVETo investigate the effect of stat3 phosphorylation and p53 expression on human epidermal non-melanoma cutaneous tumours.

METHODSImmunohistochemistry technique was employed to measure the expression of p-stat3 and p53 protein in skin tissue from 30 cases of skin squamous cell carcinoma (SCC), 20 cases of basal cell carcinoma (BCC), 20 cases of seborrhoeic keratosis (SK) and 20 normal subjects.

RESULT(1) p-stat3 protein was abnormally increased in SCC and BCC as compared with normal skin and SK. Expression of p-stat3 in SCC was also significantly higher than that in BCC. (2) Expression of p-stat3 was higher in poorly-differentiated cancers than that in well-differentiated cancers in SCC. The positive rate of p-stat3 expression was correlated with the depth of tumor invasion, but not with tumor size. (3) There was no p53 protein expression on normal skin and SK, it was significantly upregulated in SCC and BCC. In SCC, the intensity of p53 expression was associated with tumor differentiation. There was no correlation between the positive rate of p53 expression and the depth of tumor invasion, whereas the positive rate of p53 expression was correlated with the sun-exposure area. (4) There existed positive correlation between the expression intensity of p-stat3 and p53 in SCC (r=0.641, P<0.05).

CONCLUSION(1) The overexpression of p-stat3 may play an important role in the development of epidermal tumors. (2) The abnormal activation of stat3 may be related to metastatic potentials in SCC. (3) Both p53 gene and stat3 may contribute to the pathogenesis of skin SCC.

Carcinoma, Basal Cell ; chemistry ; pathology ; Carcinoma, Squamous Cell ; chemistry ; pathology ; DNA-Binding Proteins ; metabolism ; Humans ; Immunohistochemistry ; Keratosis, Seborrheic ; metabolism ; Phosphorylation ; STAT3 Transcription Factor ; Skin ; chemistry ; Skin Neoplasms ; chemistry ; pathology ; Trans-Activators ; metabolism ; Tumor Suppressor Protein p53 ; analysis

OBJECTIVETo investigate the relationship between P16 gene (the tumor suppressor gene) and the bcl-2 gene (the apoptosis inhibitor gene) and the incidence and development of malignant eyelid tumors.

METHODSThe streptavidin-biotin-peroxidase complex immunohistochemistry method was used to study the expression of P16 gene and the bcl-2 gene in 96 cases of malignant eyelid tumors.

RESULTSAmong the 96 cases, there were 40 basal cell carcinomas (BCCs), 33 squamous carcinomas and 23 sebaceous carcinoma, with P16 protein positive (nuclear staining) rates 70%, 54.6% and 56.5%, respectively. The P16 positive rate was negatively correlated with the degree of tumor histological differentiation, and the rate difference between the high differentiated carcinomas was significant (P < 0.05). Positive Bcl-2 protein expression was detected in the cytoplasm. All 40 BCC cases were Bcl-2 positive, and nearly all of the tumor cells showed positive cytoplasmic expression, while in the 33 squamous cell carcinoma cases only one showed positive focal reaction, and the staining in the other 32 cases was relatively faint. None of the 23 sebaceous carcinomas expressed Bcl-2.

CONCLUSIONSThe expression of the P16 protein was related to the occurrence and degree of differentiation of malignant eyelid tumors. The overexpression of the Bcl-2 protein suggests that suppression of apoptosis might play a role in the tumorigenesis of BCC.

Adult ; Aged ; Aged, 80 and over ; Carcinoma, Basal Cell ; chemistry ; Carcinoma, Squamous Cell ; chemistry ; Cell Differentiation ; Cyclin-Dependent Kinase Inhibitor p16 ; analysis ; Eyelid Neoplasms ; chemistry ; pathology ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Proto-Oncogene Proteins c-bcl-2 ; analysis

The expression of p53 in a variety of benign and malignant skin lesions has been first assessed in frozen sections and then compared with the results obtained in corresponding paraffin-embedded sections using various immunohistochemical staining methods with a panel of anti-p53 antibodies. Of the 48 benign and malignant skin lesions studied, 46(96%) had corresponding paraffin sections and immunohistochemical results obtained with DO7 on frozen and paraffin sections were concordant in 97%, qualitatively. Using streptavidin-biotin complex method, p53 was identified in 33% of dysplastic squamous lesions, 50% of squamous cell carcinomas (SCCs) and 36% of basal cell carcinomas (BCCs) on frozen section, whereas 25% of dysplastic squamous lesions, 40% of SCCs, and 32% of BCCs showed p53 positivity on paraffin-embedded sections. In frozen sections, the same regions of each specimen exhibited similar topographic patterns of positive immunoreactivity with both monoclonal antibodies, PAb 1801 and DO7. In contrast, immunohistochemical staining with polyclonal antibody, CM-1, gave poor morphologic resolution, although effective in paraffin-embedded sections.
Animals ; Antibodies, Monoclonal/*immunology ; Carcinoma, Basal Cell/chemistry ; Humans ; Immunohistochemistry ; Mice ; Skin Neoplasms/*chemistry ; Staining and Labeling ; Tumor Suppressor Protein p53/*analysis/immunology

The link of hedgehog (Hh) signaling activation to human cancer and synthesis of a variety of Hh signaling inhibitors raise great expectation that inhibiting Hh signaling may be effective in human cancer treatment. Cyclopamine (Cyc), an alkaloid from the Veratrum plant, is a specific natural product inhibitor of the Hh pathway that acts by targeting smoothened (SMO) protein. However, its poor solubility, acid sensitivity, and weak potency relative to other Hh antagonists prevent the clinical development of Cyc as a therapeutic agent. Here, we report properties of cyclopamine tartrate salt (CycT) and its activities in Hh signaling-mediated cancer in vitro and in vivo. Unlike Cyc, CycT is water soluble (5-10 mg/mL). The median lethal dose (LD50) of CycT was 62.5 mg/kg body weight compared to 43.5 mg/kg for Cyc, and the plasma half-life (T1/2) of CycT was not significantly different from that of Cyc. We showed that CycT had a higher inhibitory activity for Hh signaling-dependent motor neuron differentiation than did Cyc (IC50 = 50 nmol/L for CycT vs. 300 nmol/L for Cyc). We also tested the antitumor effectiveness of these Hh inhibitors using two mouse models of basal cell carcinomas (K14cre:Ptch1(neo/neo) and K14cre:SmoM2(YFP)). After topical application of CycT or Cyc daily for 21 days, we found that all CycT-treated mice had tumor shrinkage and decreased expression of Hh target genes. Taken together, we found that CycT is an effective inhibitor of Hh signaling-mediated carcinogenesis.
Animals ; Carcinoma, Basal Cell ; pathology ; Cell Differentiation ; drug effects ; Embryonic Stem Cells ; cytology ; Hedgehog Proteins ; antagonists & inhibitors ; metabolism ; Mice ; Motor Neurons ; cytology ; Plants, Medicinal ; chemistry ; Receptors, G-Protein-Coupled ; antagonists & inhibitors ; metabolism ; Signal Transduction ; drug effects ; Skin Neoplasms ; pathology ; Smoothened Receptor ; Solubility ; Tartrates ; blood ; pharmacology ; Tumor Burden ; drug effects ; Veratrum ; chemistry ; Veratrum Alkaloids ; blood ; isolation & purification ; pharmacology

The expression of the p53 protein (p53) was compared with those of several oncogenes including c-fos (Fos), c-jun (Jun), and epidermal growth factor receptor (EGFR1) using immunohistochemistry in frozen and paraffin-embedded sections of 25 basal cell carcinomas (BCCs) to find out any correlation between p53 and oncogenes in the pathogenesis of human BCC. In normal skin, positive reactions were obtained for EGFR1 and Fos, while p53 and Jun were negative in all cases. In the lesions, EGFR1 was observed in all cases and p53 was positive in 9 of 25 (36%). Fos was expressed in 21 of 25 (84%) and four negative cases were all p53-positive; this negative correlation between p53 and Fos staining was statistically significant (P< 0.01). Jun was detected in 14 of 20 (70%) and no significant relationship was observed between the expression of Jun and Fos or p53. These data suggest the possibility of down regulation of Fos expression by high levels of p53 protein. Further work is necessary to determine the mechanism of this interaction.
Aged ; Carcinoma, Basal Cell/chemistry/*genetics ; Comparative Study ; Female ; Gene Expression ; Genes, fos ; Genes, jun ; Genes, p53 ; Human ; Immunohistochemistry ; Male ; Middle Age ; Oncogene Protein p65(gag-jun)/analysis ; Oncogene Proteins v-fos/analysis ; *Oncogenes ; Protein p53/analysis ; Receptor, Epidermal Growth Factor/analysis ; Skin Neoplasms/chemistry/*genetics