Obstetrics and Gynaecology - Research Publications

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    The New Generation Antiplatelet Agent Prasugrel Represents an Exciting Novel Candidate Therapy for Preeclampsia.
    De Alwis, N ; Binder, N ; Beard, S ; Vi, N ; Tu'uhevaha, K-L ; Tong, S ; Hannan, N (SPRINGER HEIDELBERG, 2020-03)
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    Jagged1 Regulates Endometrial Receptivity in Both Humans and Mice.
    Zhou, W ; Menkhorst, E ; Dimitriadis, E (SPRINGER HEIDELBERG, 2021-07-01)
    The human endometrium undergoes cycle-dependent changes and is only receptive to an implanting blastocyst within a narrow window of 2-4 days in the mid-secretory phase. Such functional changes require delicate interplay between a diversity of factors including cytokines and signaling pathways. The Notch signaling pathway members are expressed in human endometrium. We have previously demonstrated that Notch ligand Jagged1 (JAG1) localizes in the endometrial luminal epithelium (LE) and is abnormally reduced in infertile women during receptivity. However, the functional consequences of reduced JAG1 production on endometrial receptivity to implantation of the blastocyst are unknown. This study aimed to determine the role of JAG1 in regulating endometrial receptivity in humans and mice. Knockdown of JAG1 in both primary human endometrial epithelial cells and Ishikawa cells significantly reduced their adhesive capacity to HTR8/SVneo (trophoblast cell line) spheroids. We confirmed that in human endometrial epithelial cells, JAG1 interacted with Notch Receptor 3 (NOTCH3) and knockdown of JAG1 significantly reduced the expression of Notch signaling downstream target HEY1 and classical receptivity markers. Knockdown of Jag1 in mouse LE significantly impaired blastocyst implantation. We identified ten genes (related to tight junction, infertility, and cell adhesion) that were differentially expressed by Jag1 knockdown in LE in mice. Further analysis of the tight junction family members in both species revealed that JAG1 altered the expression of tight junction components only in mice. Together, our data demonstrated that JAG1 altered endometrial epithelial cell adhesive capacity and regulated endometrial receptivity in both humans and mice likely via different mechanisms.
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    Galectin-7: A Novel Placental-released Driver of Preeclampsia.
    Menkhorst, E ; Zhou, W ; So, T ; Santos, L ; Zhang, J-G ; Syngelaki, A ; Nicolaides, K ; St-Pierre, Y ; Dimitriadis, E (SPRINGER HEIDELBERG, 2020-03)
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    New Insights into the Nature and Role of Potassium Channels in Regulating Uterine Contraction in Human Labour.
    Siriwardhana, R ; Tonta, MA ; Sheehan, PM ; Coleman, HA ; Brennecke, SP ; Parkington, HC (Springer, 2020-03-01)
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    Psychosocial disadvantage and residential remoteness is associated with Aboriginal women's mental health prior to childbirth
    Bhat, SK ; Marriott, R ; Galbally, M ; Shepherd, CCJ (SWANSEA UNIV, 2020)
    INTRODUCTION: Optimal mental health in the pre-conception, pregnancy and postpartum periods is important for both maternal and infant wellbeing. Few studies, however, have focused on Indigenous women and the specific risk and protective factors that may prompt vulnerability to perinatal mental disorders in this culturally diverse population. OBJECTIVES: To assess mental health contacts in the period before childbirth among Australian Aboriginal and Torres Strait Islander women, the association with socioeconomic factors and whether it differs by geographic remoteness. METHODS: This is a retrospective cohort study of 19,165 Aboriginal mothers and includes all Aboriginal mothers and their children born in Western Australia from January 1990 to March 2015. It draws on population-level, linked administrative data from hospitals and mental health services, with a primary focus on the mental health contacts of Aboriginal women in the 5 years leading up to childbirth. RESULTS: The prevalence of maternal mental health contacts in the five years prior to birth was 27.6% (93.6% having a single mental health disorder), with a greater likelihood of contact in metropolitan areas compared with regional and remote settings. There was a positive relationship between socioeconomic advantage and the likelihood of a mental health contact for women in Metropolitan (β = 0.044, p=0.003) and Inner regional areas (β = 0.033, p=0.018), and a negative association in Outer regional (β = -0.038, p=0.022), Remote (β = -0.019, p=0.241) and Very remote regions (β = -0.053, p<0.001). CONCLUSIONS: The findings from this study provide new insights on the dynamic relationship between SES, geographic location and mental health issues among Aboriginal women in the 5 years leading up to childbirth. The results underscore the need to apply location-specific approaches to addressing the material and psychosocial pathways that lead to mental health problems and the provision of culturally safe, appropriate and accessible services for Aboriginal women.
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    The cognitive, affective, social and environmental drivers of inappropriate ovarian cancer screening: A survey of women and their clinicians using the theoretical domains framework
    Macdonald, C ; Mazza, D ; Hickey, M ; Hunter, M ; Keogh, LA ; Jones, SC ; Saunders, C ; Nesci, S ; Milne, RL ; McLachlan, SA ; Hopper, J ; Friedlander, M ; Emery, J ; Phillips, KA (ELSEVIER, 2020-09)
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    Inhibition of RNA polymerase I transcription activates targeted DNA damage response and enhances the efficacy of PARP inhibitors in high-grade serous ovarian cancer.
    Sanij, E ; Hannan, K ; Xuan, J ; Yan, S ; Ahern, JA ; Trigos, AS ; Brajanovski, N ; Son, J ; Chan, KT ; Kondrashova, O ; Lieschke, E ; Wakefield, MJ ; Ellis, S ; Cullinane, C ; Poortinga, G ; Khanna, KK ; Mileshkin, L ; McArthur, GA ; Soong, J ; Berns, EM ; Hannan, RD ; Scott, CL ; Sheppard, KE ; Pearson, RB (AMER ASSOC CANCER RESEARCH, 2020-07)
    Abstract Introduction: PARP inhibitors (PARPi) have revolutionized disease management of patients with homologous recombination (HR) DNA repair-deficient high-grade serous ovarian cancer (HGSOC). However, acquired resistance to PARPi is a major challenge in the clinic. The specific inhibitor of RNA polymerase I (Pol I) transcription of ribosomal RNA genes (rDNA) has demonstrated single-agent antitumor activity in p53 wild-type and p53-mutant hematologic malignancies (first-in-human trial, dose escalation study of CX-5461 at Peter MacCallum Cancer Centre) (Khot et al., Cancer Discov 2019). CX-5461 has also been reported to exhibit synthetic lethality with BRCA1/2 deficiency through stabilization of G-quadruplex DNA (GQ) structures. Here, we investigate the efficacy of CX-5461 in treating HGSOC. Experimental Design: The mechanisms by which CX-5461 induces DNA damage response (DDR) and displays synthetic lethality in HR-deficient HGSOC cells are explored. We present in vivo data of mice bearing two functionally and genomically profiled HGSOC-patient-derived xenograft (PDX)s treated with CX-5461 and olaparib, alone and in combination. We also investigate CX-5461-sensitivity gene expression signatures in primary and relapsed HGSOC. Results: Utilizing ovarian cancer cell lines, we demonstrate that sensitivity to CX-5461 is associated with “BRCA1 mutation” and “MYC targets” gene expression signatures. In addition, sensitivity to CX-5461 is associated with high basal rates of Pol I transcription. Importantly, we demonstrate a novel mechanism for CX-5461 synthetic lethal interaction with HR deficiency mediated through the induction of replication stress at rDNA repeats. Our data reveal CX-5461-mediated DDR in HR-deficient cells does not involve stabilization of GQ structures as previously proposed. On the contrary, we show definitively that CX-5461 inhibits Pol I recruitment leading to rDNA chromatin defects including stabilization of R-loops, single-stranded DNA, and replication stress at the rDNA. Mechanistically, we demonstrate CX-5461 leads to replication-dependent DNA damage involving MRE11-dependent degradation of replication forks. Importantly, CX-5461 has a different sensitivity spectrum to olaparib and cooperates with PARPi in exacerbating replication stress, leading to enhanced therapeutic efficacy in HR-deficient HGSOC-PDX in vivo compared to single-agent treatment of both drugs. Further, CX-5461 exhibits single-agent efficacy in olaparib-resistant HGSOC-PDX overcoming PARPi-resistance mechanisms involving fork protection. Importantly, we identify CX-5461-sensitivity gene expression signatures in primary and relapsed HGSOC. Conclusions: CX-5461 is a promising therapy alone and in combination therapy with PARPi in HR-deficient HGSOC. CX-5461 also has exciting potential as a treatment option for patients with relapsed HGSOC tumors that have high MYC activity and poor clinical outcome; these patients currently have very limited effective treatment options. This abstract is also being presented as Poster A71. Citation Format: Elaine Sanij, Katherine Hannan, Jiachen Xuan, Shunfei Yan, Jessica A. Ahern, Anna S. Trigos, Natalie Brajanovski, Jinbae Son, Keefe T. Chan, Olga Kondrashova, Elizabeth Lieschke, Matthew J. Wakefield, Sarah Ellis, Carleen Cullinane, Gretchen Poortinga, Kum Kum Khanna, Linda Mileshkin, Grant A. McArthur, John Soong, Els M. Berns, Ross D. Hannan, Clare L. Scott, Karen E. Sheppard, Richard B. Pearson. Inhibition of RNA polymerase I transcription activates targeted DNA damage response and enhances the efficacy of PARP inhibitors in high-grade serous ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr PR13.