scholarly journals Non-Phosphorylatable PEA-15 Sensitises SKOV-3 Ovarian Cancer Cells to Cisplatin

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 515 ◽  
Author(s):  
Shahana Dilruba ◽  
Alessia Grondana ◽  
Anke C. Schiedel ◽  
Naoto T. Ueno ◽  
Chandra Bartholomeusz ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Nuclear Translocation ◽  
Antioxidant Response ◽  
The Cancer Genome Atlas ◽  
Favourable Effect ◽  
Ovarian Cancer Cells ◽  
Related Factor ◽  
Potential Candidate ◽  
Cisplatin Sensitivity

The efficacy of cisplatin-based chemotherapy in ovarian cancer is often limited by the development of drug resistance. In most ovarian cancer cells, cisplatin activates extracellular signal-regulated kinase1/2 (ERK1/2) signalling. Phosphoprotein enriched in astrocytes (PEA-15) is a ubiquitously expressed protein, capable of sequestering ERK1/2 in the cytoplasm and inhibiting cell proliferation. This and other functions of PEA-15 are regulated by its phosphorylation status. In this study, the relevance of PEA-15 phosphorylation state for cisplatin sensitivity of ovarian carcinoma cells was examined. The results of MTT-assays indicated that overexpression of PEA-15AA (a non-phosphorylatable variant) sensitised SKOV-3 cells to cisplatin. Phosphomimetic PEA-15DD did not affect cell sensitivity to the drug. While PEA-15DD facilitates nuclear translocation of activated ERK1/2, PEA-15AA acts to sequester the kinase in the cytoplasm as shown by Western blot. Microarray data indicated deregulation of thirteen genes in PEA-15AA-transfected cells compared to non-transfected or PEA-15DD-transfected variants. Data derived from The Cancer Genome Atlas (TCGA) showed that the expression of seven of these genes including EGR1 (early growth response protein 1) and FLNA (filamin A) significantly correlated with the therapy outcome in cisplatin-treated cancer patients. Further analysis indicated the relevance of nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) signalling for the favourable effect of PEA-15AA on cisplatin sensitivity. The results warrant further evaluation of the PEA-15 phosphorylation status as a potential candidate biomarker of response to cisplatin-based chemotherapy.

scholarly journals FEN1 Blockade for Platinum Chemo-Sensitization and Synthetic Lethality in Epithelial Ovarian Cancers

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1866
Author(s):  
Katia A. Mesquita ◽  
Reem Ali ◽  
Rachel Doherty ◽  
Michael S. Toss ◽  
Islam Miligy ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
High Throughput Screening ◽  
Nuclear Translocation ◽  
Synthetic Lethality ◽  
Excision Repair ◽  
Progression Free Survival ◽  
Ovarian Cancer Cells ◽  
Physical Interaction ◽  
Base Excision

FEN1 plays critical roles in long patch base excision repair (LP-BER), Okazaki fragment maturation, and rescue of stalled replication forks. In a clinical cohort, FEN1 overexpression is associated with aggressive phenotype and poor progression-free survival after platinum chemotherapy. Pre-clinically, FEN1 is induced upon cisplatin treatment, and nuclear translocation of FEN1 is dependent on physical interaction with importin β. FEN1 depletion, gene inactivation, or inhibition re-sensitizes platinum-resistant ovarian cancer cells to cisplatin. BRCA2 deficient cells exhibited synthetic lethality upon treatment with a FEN1 inhibitor. FEN1 inhibitor-resistant PEO1R cells were generated, and these reactivated BRCA2 and overexpressed the key repair proteins, POLβ and XRCC1. FEN1i treatment was selectively toxic to POLβ deficient but not XRCC1 deficient ovarian cancer cells. High throughput screening of 391,275 compounds identified several FEN1 inhibitor hits that are suitable for further drug development. We conclude that FEN1 is a valid target for ovarian cancer therapy.

scholarly journals Promotion of Cell Death in Cisplatin-Resistant Ovarian Cancer Cells through KDM1B-DCLRE1B Modulation

2019 ◽  
Vol 20 (10) ◽  
pp. 2443 ◽  
Author(s):  
Yeon Kyu Lee ◽  
Jinyeong Lim ◽  
So Young Yoon ◽  
Jong Cheon Joo ◽  
Soo Jung Park ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Ovarian Cancer Cells ◽  
Repair Gene ◽  
Gynecological Malignancy ◽  
Downstream Target ◽  
Dna Repair Gene ◽  
Cisplatin Sensitivity

Ovarian cancer is the gynecological malignancy with the poorest prognosis, in part due to its high incidence of recurrence. Platinum agents are widely used as a first-line treatment against ovarian cancer. Recurrent tumors, however, frequently demonstrate acquired chemo-resistance to platinum agent toxicity. To improve chemo-sensitivity, combination chemotherapy regimens have been investigated. This study examined anti-tumor effects and molecular mechanisms of cytotoxicity of Oldenlandia diffusa (OD) extracts on ovarian cancer cells, in particular, cells resistant to cisplatin. Six ovarian cancer cells including A2780 and cisplatin-resistant A2780 (A2780cis) as representative cell models were used. OD was extracted with water (WOD) or 50% methanol (MOD). MOD significantly induced cell death in both cisplatin-sensitive cells and cisplatin-resistant cells. The combination treatment of MOD with cisplatin reduced viability in A2780cis cells more effectively than treatment with cisplatin alone. MOD in A2780cis cells resulted in downregulation of the epigenetic modulator KDM1B and the DNA repair gene DCLRE1B. Transcriptional suppression of KDM1B and DCLRE1B induced cisplatin sensitivity. Knockdown of KDM1B led to downregulation of DCLRE1B expression, suggesting that DCLRE1B was a KDM1B downstream target. Taken together, OD extract effectively promoted cell death in cisplatin-resistant ovarian cancer cells under cisplatin treatment through modulating KDM1B and DCLRE1B.

scholarly journals NRF2 Regulates HER1 Signaling Pathway to Modulate the Sensitivity of Ovarian Cancer Cells to Lapatinib and Erlotinib

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Ibrahim H. Kankia ◽  
Hilal S. Khalil ◽  
Simon P. Langdon ◽  
Peter R. Moult ◽  
James L. Bown ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Cellular Proliferation ◽  
Ovarian Cancer Cells ◽  
Epidermal Growth Factor Receptors ◽  
Related Factor ◽  
Her Family ◽  
Epidermal Growth ◽  
Nrf2 Activator ◽  
Sirna Knockdown

NF-E2-related factor 2 (NRF2) regulates the transcription of a battery of metabolic and cytoprotective genes. NRF2 and epidermal growth factor receptors (EGFRs/HERs) are regulators of cellular proliferation and determinants of cancer initiation and progression. NRF2 and HERs confer cancers with resistance to several therapeutic agents. Nevertheless, there is limited understanding of the regulation of HER expression and activation and the link between NRF2 and HER signalling pathways. We show that NRF2 regulates both basal and inducible expression ofHER1, as treatment of ovarian cancer cells (PEO1, OVCAR3, and SKOV3) with NRF2 activator tBHQ inducingHER1, while inhibition of NRF2 by siRNA knockdown or with retinoid repressesHER1. Furthermore, treatment of cells with tBHQ increased total and phosphorylated NRF2, HER1, and AKT levels and compromised the cytotoxic effect of lapatinib or erlotinib. Treatment with siRNA or retinoid antagonised the effect of tBHQ on NRF2 and HER1 levels and enhanced the sensitivity of ovarian cancer cells to lapatinib or erlotinib. Pharmacological or genetic inhibition of NRF2 and/or treatment with lapatinib or erlotinib elevated cellular ROS and depleted glutathione. This extends the understanding of NRF2 and its regulation of HER family receptors and opens a strategic target for improving cancer therapy.

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