Immunohistochemical expression of CD117 in borderline, low- and high-grade ovarian surface epithelial tumours: A clinicopathological study

INTRODUCTION

Ovarian cancer is one of leading causes of cancer related death in gynecology. CD117 is a tyrosine kinase receptor that plays an important role in regulation of apoptosis, cell proliferation and adhesion by binding to its ligand-stem cell factor. Recent studies demonstrated its aberrant overexpression in various malignancies and concluded that it may play a pivotal role in carcinogenesis.

AIM

To evaluate CD117 expression in ovarian surface epithelial tumours.

MATERIALS AND METHODS

This retrospective study included 30 ovarian epithelial borderline, low and highly malignant tumours' formalin-fixed paraffin-blocks (FFPE) tissue blocks. Tissue sections were subjected to the routine haematoxylin-eosin stain and with the anti-CD117 immunohistochemically.

RESULTS

There is a high significant difference in CD117 expression between borderline and malignant groups (P = 0.001). Additionally, there was significant difference in expression in relation to histopathological type (serous versus non-serous) in low-grade and the high-grade ovarian surface epithelial tumours (p=0.04, p=0.035 respectively). Tumour grade and stage strongly correlates with CD117 expression (p=0.014, p=0.019 respectively).

CONCLUSION

We concluded that CD117 expression was significantly correlated with higher ovarian tumour grade and stage.

Key features of the environment promoting liver cancer in the absence of cirrhosis

The prevalence of obesity and non-alcoholic fatty liver disease (NAFLD) associated hepatocellular carcinoma (HCC) is rising, even in the absence of cirrhosis. We aimed to develop a murine model that would facilitate further understanding of NAFLD-HCC pathogenesis. A total of 144 C3H/He mice were fed either control or American lifestyle (ALIOS) diet, with or without interventions, for up to 48 weeks of age. Gross, liver histology, immunohistochemistry (IHC) and RNA-sequencing data were interpreted alongside human datasets. The ALIOS diet promoted obesity, elevated liver weight, impaired glucose tolerance, non-alcoholic fatty liver disease (NAFLD) and spontaneous HCC. Liver weight, fasting blood glucose, steatosis, lobular inflammation and lipogranulomas were associated with development of HCC, as were markers of hepatocyte proliferation and DNA damage. An antioxidant diminished cellular injury, fibrosis and DNA damage, but not lobular inflammation, lipogranulomas, proliferation and HCC development. An acquired CD44 phenotype in macrophages was associated with type 2 diabetes and NAFLD-HCC. In this diet induced NASH and HCC (DINAH) model, key features of obesity associated NAFLD-HCC have been reproduced, highlighting roles for hepatic steatosis and proliferation, with the acquisition of lobular inflammation and CD44 positive macrophages in the development of HCC-even in the absence of progressive injury and fibrosis.

Targeting negative regulation of p53 by MDM2 and WIP1 as a therapeutic strategy in cutaneous melanoma

BACKGROUND

Cutaneous melanoma is the most serious skin malignancy and new therapeutic strategies are needed for advanced melanoma. TP53 mutations are rare in cutaneous melanoma and hence activation of wild-type p53 is a potential therapeutic strategy in cutaneous melanoma. Here, we investigated the WIP1 inhibitor, GSK2830371, and MDM2-p53 binding antagonists (nutlin-3, RG7388 and HDM201) alone and in combination treatment in cutaneous melanoma cell lines and explored the mechanistic basis of these responses in relation to the genotype and induced gene expression profile of the cells.

METHODS

A panel of three p53WT (A375, WM35 and C8161) and three p53MUT (WM164, WM35-R and CHL-1) melanoma cell lines were used. The effects of MDM2 and WIP1 inhibition were evaluated by growth inhibition and clonogenic assays, immunoblotting, qRT-PCR gene expression profiling and flow cytometry.

RESULTS

GSK2830371, at doses (⩽10 μM) that alone had no growth-inhibitory or cytotoxic effects on the cells, nevertheless significantly potentiated the growth-inhibitory and clonogenic cell killing effects of MDM2 inhibitors in p53WT but not p53MUT melanoma cells, indicating the potentiation worked in a p53-dependent manner. The siRNA-mediated knockdown of p53 provided further evidence to support the p53 dependence. GSK2830371 increased p53 stabilisation through Ser15 phosphorylation and consequent Lys382 acetylation, and decreased ubiquitination and proteasome-dependent degradation when it was combined with MDM2 inhibitors. These changes were at least partly ATM mediated, shown by reversal with the ATM inhibitor (KU55933). GSK2830371 enhanced the induction of p53 transcriptional target genes, cell cycle arrest and apoptosis.

CONCLUSIONS

GSK2830371, a WIP1 inhibitor, at doses with no growth-inhibitory activity alone, potentiated the growth-inhibitory and cytotoxic activity of MDM2 inhibitors by increasing phosphorylation, acetylation and stabilisation of p53 in cutaneous melanoma cells in a functional p53-dependent manner.

Abstract 2151: Inhibition of WIP1/PPM1D phosphatase by GSK2830371 potentiates the growth inhibitory and cytotoxic activity of MDM2 antagonists (nutlin-3, RG7388 and HDM201) in cutaneous melanoma cells

Cutaneous melanoma is the most serious skin malignancy. The current study aimed to investigate the WIP1 inhibitor GSK2830371 and MDM2-p53 antagonists (nutlin-3, RG7388 and HDM201) alone and in combination treatment in cutaneous melanoma cell lines and explored the mechanistic basis of these responses in relation to the genotype and induced gene expression profile of the cells. A panel of three p53WT (A375, WM35, C8161) and three p53MUT (WM164, WM35-R5R1, CHL-1) melanoma cell lines were used. GSK2830371 (≤10 μM) alone had no growth-inhibitory or cytotoxic effects on the cells, measured by sulforhodamine B (SRB) and clonogenic assays. In combination treatment GSK2830371 significantly potentiated the growth-inhibitory and clonogenic cell killing effects of MDM2 inhibitors in p53WT but not p53MUT melanoma cells, indicating the potentiation worked in a p53-dependent manner (Table). Western blotting demonstrated GSK2830371 increased p53 stabilization through Ser15 phosphorylation and consequent Lys382 acetylation when it was combined with MDM2 inhibitors. These changes were ATM-mediated, shown by reversal with the ATM inhibitor (KU55933). Furthermore, GSK2830371 was demonstrated to slow down p53 degradation when de-novo protein synthesis was inhibited by cycloheximide. In qRT-PCR, nutlin-3 or RG7388 induced p53 transcriptional target genes (CDKN1A, MDM2, BAX, FAS, PUMA, TNFBSF10B, TP53INP1) and GSK2830371 enhanced the induction in p53WT but not p53MUT cells. In conclusion, GSK2830371, a WIP1 inhibitor, at doses with no growth-inhibitory activity alone, potentiated the growth-inhibitory and cytotoxic activity of MDM2 inhibitors, by increasing phosphorylation, acetylation, and stabilization of p53 in cutaneous melanoma cells in a functional p53-dependent manner. Further studies in vivo are warranted to investigate the efficacy of this combination treatment.

GI50 by sulforhodamine B (SRB) and LC50 by clonogenic assays in p53WT melanoma cellsCell linesGI50 (Mean + SEM)A375WM35C8161GSK2830371-+-+-+Nutlin-3 (µM)5.1 + 0.61.5 + 0.48.3 + 1.55.3 + 1.41.7 + 0.31.0 + 0.5p value0.0120.0100.049RG7388 (nM)228 + 3962 + 2377 + 58169 + 5746 + 015 + 5p value0.0250.0280.009HDM201 (nM)167 + 2541 + 9165 + 9877 + 5981 + 1149 + 10p value0.00460.1048< 0.001LC50 (Mean + SEM)A375WM35C8161GSK2830371-+-+-+Nutlin-3 (µM)2.0 + 0.90.8 + 0.50.5 + 0.10.4 + 0.10.9 + 0.20.4 + 0.1p value0.0400.07140.003RG7388 (nM)166 + 9554 + 37186 + 7868 + 2350 + 2221 + 10p value0.0060.0700.026HDM201 (nM)198 + 7015 + 411 + 38 + 3139 + 8519 + 5p value<0.0010.10620.010

Citation Format: Chiao-En Wu, Arman Esfandiari, Yi-Hsuan Ho, Colin Shepherd, Ahmed Khairallah Mahdi, Erhan Aptullahoglu, John Wen-Cheng Chang, Penny Lovat, John Lunec. Inhibition of WIP1/PPM1D phosphatase by GSK2830371 potentiates the growth inhibitory and cytotoxic activity of MDM2 antagonists (nutlin-3, RG7388 and HDM201) in cutaneous melanoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2151. doi:10.1158/1538-7445.AM2017-2151