PAX2 Expression in Ovarian Cancer

PAX2 is one of nine PAX genes that regulate tissue development and cellular differentiation in embryos. However, the functional role of PAX2 in ovarian cancer is not known. Twenty-six ovarian cancer cell lines with different histology origins were screened for PAX2 expression. Two ovarian cancer cell lines: RMUGL (mucinous) and TOV21G (clear cell), with high PAX2 expression were chosen for further study. Knockdown PAX2 expression in these cell lines was achieved by lentiviral shRNAs targeting the PAX2 gene. PAX2 stable knockdown cells were characterized for cell proliferation, migration, apoptosis, protein profiles, and gene expression profiles. The result indicated that these stable PAX2 knockdown cells had reduced cell proliferation and migration. Microarray analysis indicated that several genes involved in growth inhibition and motility, such as G0S2, GREM1, and WFDC1, were up-regulated in PAX2 knockdown cells. On the other hand, over-expressing PAX2 in PAX2-negative ovarian cell lines suppressed their cell proliferation. In summary, PAX2 could have both oncogenic and tumor suppression functions, which might depend on the genetic content of the ovarian cancer cells. Further investigation of PAX2 in tumor suppression and mortality is warranty

PAX2 Expression in Ovarian Cancer

PAX2 is one of nine PAX genes that regulate tissue development and cellular differentiation in embryos. However, the functional role of PAX2 in ovarian cancer is not known. Twenty-six ovarian cancer cell lines with different histology origins were screened for PAX2 expression. Two ovarian cancer cell lines: RMUGL (mucinous) and TOV21G (clear cell), with high PAX2 expression were chosen for further study. Knockdown PAX2 expression in these cell lines was achieved by lentiviral shRNAs targeting the PAX2 gene. PAX2 stable knockdown cells were characterized for cell proliferation, migration, apoptosis, protein profiles, and gene expression profiles. The result indicated that these stable PAX2 knockdown cells had reduced cell proliferation and migration. Microarray analysis indicated that several genes involved in growth inhibition and motility, such as G0S2, GREM1, and WFDC1, were up-regulated in PAX2 knockdown cells. On the other hand, over-expressing PAX2 in PAX2-negative ovarian cell lines suppressed their cell proliferation. In summary, PAX2 could have both oncogenic and tumor suppression functions, which might depend on the genetic content of the ovarian cancer cells. Further investigation of PAX2 in tumor suppression and mortality is warranty

Nutlin-3a: A Potential Therapeutic Opportunity for TP53 Wild-Type Ovarian Carcinomas.

Epithelial ovarian cancer is a diverse molecular and clinical disease, yet standard treatment is the same for all subtypes. TP53 mutations represent a node of divergence in epithelial ovarian cancer histologic subtypes and may represent a therapeutic opportunity in subtypes expressing wild type, including most low-grade ovarian serous carcinomas, ovarian clear cell carcinomas and ovarian endometrioid carcinomas, which represent approximately 25% of all epithelial ovarian cancer. We therefore sought to investigate Nutlin-3a--a therapeutic which inhibits MDM2, activates wild-type p53, and induces apoptosis--as a therapeutic compound for TP53 wild-type ovarian carcinomas. Fifteen epithelial ovarian cancer cell lines of varying histologic subtypes were treated with Nutlin-3a with determination of IC50 values. Western Blot (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) analyses quantified MDM2, p53, and p21 expression after Nutlin-3a treatment. DNA from 15 cell lines was then sequenced for TP53 mutations in exons 2-11 including intron-exon boundaries. Responses to Nutlin-3a were dependent upon TP53 mutation status. By qRT-PCR and WB, levels of MDM2 and p21 were upregulated in wild-type TP53 sensitive cell lines, and p21 induction was reduced or absent in mutant cell lines. Annexin V assays demonstrated apoptosis in sensitive cell lines treated with Nutlin-3a. Thus, Nutlin-3a could be a potential therapeutic agent for ovarian carcinomas expressing wild-type TP53 and warrants further investigation

List of genes significantly up-regulated in Nutlin-3a resistant cancer cell lines with wild-type <i>TP53</i>.

<p>List of genes significantly up-regulated in Nutlin-3a resistant cancer cell lines with wild-type <i>TP53</i>.</p

Protein expression of <i>TP53</i> and p21 of ovarian cancer cell lines after treated with Nutlin-3a for 24, 48 and 72 hours at their corresponding IC50 as indicated in Table 1.

<p>C, untreated control; *, cancer cell lines carrying <i>TP53</i> mutation. Het, heterozygous TP53 mutation; hom, homozygous <i>TP53</i> mutation.</p

Cell viability of ovarian cancer cell lines treated with Nutlin-3a.

<p>All 15 cell lines were plated at a density of 1 × 10³ cells per well in 96-well plates. After 24h, media was exchanged and cells were treated with incremental concentrations of Nutlin-3a (1 μM, 5 μM, 10 μM, 25 μM, 50 μM, and 70 μM). After 72h of Nutlin-3a treatment, cell viability was measured by WST assay and compared to untreated control.</p

Gene expression of p21, <i>TP53</i>, and MDM2 of ovarian cancer cell lines after treated with Nutlin-3a for 24, 48 and 72 hours at their corresponding IC50 as indicated in Table 1.

<p>(A) <i>TP53</i>. (B) p21. (C) MDM2.</p

<i>TP53</i> mutation status and Nutlin-3a sensitivity of ovarian cancer cell lines.

<p>ATCC, American Type Culture Collection; JCRB, Japanese Collection of Research Bioresources Cell Bank.</p><p><i>TP53</i> mutation status and Nutlin-3a sensitivity of ovarian cancer cell lines.</p