PAX2 Regulates ADAM10 Expression and Mediates Anchorage-Independent Cell Growth of Melanoma Cells

Abstract

PAX transcription factors play an important role during development and carcinogenesis. In this study, we investigated PAX2 protein levels in melanocytes and melanoma cells by Western Blot and immunofluorescence analysis and characterized the role of PAX2 in the pathogenesis of melanoma. In vitro we found weak PAX2 protein expression in keratinocytes and melanocytes. Compared to melanocytes increased PAX2 protein levels were detectable in melanoma cell lines. Interestingly, in tissue sections of melanoma patients nuclear PAX2 expression strongly correlated with nuclear atypia and the degree of prominent nucleoli, indicating an association of PAX2 with a more atypical cellular phenotype. In addition, with chromatin immunoprecipitation assay, PAX2 overexpression and PAX2 siRNA we present compelling evidence that PAX2 can regulate ADAM10 expression, a metalloproteinase known to play important roles in melanoma metastasis. In human tissue samples we found co-expression of PAX2 and ADAM10 in melanocytes of benign nevi and in melanoma cells of patients with malignant melanoma. Importantly, the downregulation of PAX2 by specific siRNA inhibited the anchorage independent cell growth and decreased the migratory and invasive capacity of melanoma cells. Furthermore, the downregulation of PAX2 abrogated the chemoresistance of melanoma cells against cisplatin, indicating that PAX2 expression mediates cell survival and plays important roles during melanoma progression.

PAX2 (Paired box gene 2)

“…Note PAX2 protein was expressed weakly in keratinocytes and melanocytes (Lee et al, 2011). Increased levels of PAX2 protein, as compared to melanocytes, were observed in some melanoma cell lines, and in some melanoma tissues, which strongly correlated with nuclear atypia and prominent nucleoli (i.e a more atypical cellular phenotype).…”

“…Increased levels of PAX2 protein, as compared to melanocytes, were observed in some melanoma cell lines, and in some melanoma tissues, which strongly correlated with nuclear atypia and prominent nucleoli (i.e a more atypical cellular phenotype). PAX2 was found to regulate ADAM10 expression, which is a metalloproteinase with an important role in melanoma, and the silencing of PAX2 expression in melanoma cells abrogated chemoresistance, and anchorage-independent growth as well as decreasing migratory and invasive capacity of melanoma cells (Lee et al, 2011).…”

Upregulation of PAX2 Promotes the Metastasis of Esophageal Cancer through Interleukin-5

“…The downstream target genes of PAX2 have gradually been identified, and GDNF has been reported to be a PAX2 target in medulloblastoma [36]. PAX2 can regulate metalloproteinase ADAM10 expression by driving melanoma metastasis [39]. In colon cancer cells, PAX2 upregulates Cyclin D1 mediated by AP-1 to promote cell proliferation [21].…”

Expression of Pax2 protein during the formation of the central nervous system in human embryos

“…The slides were treated with normal 1.5% goat serum (Gibco, Invitrogen, USA) for 30 min at room temperature and incubated with the primary antibody Pax2 (4 µg/mL dilution in 0.1 M PBS, abcam, UK) overnight at 4°C in a humidity chamber. The primary antibody used was rabbit polyclonal antibody to Pax2 (abcam, ab23799), which has been reported to perform excellently in immunohistochemical applications with paraffin embedded human samples [13] as well in Western blotting applications with human tissue samples [6].…”