Deletion of PTP4A3 phosphatase in high grade serous ovarian cancer cells decreases tumorigenicity and produces marked changes in intracellular signaling pathways and cytokine release.

The oncogenic protein tyrosine phosphatase PTP4A3 is frequently overexpressed in human ovarian cancers and is associated with poor patient prognosis. PTP4A3 is thought to regulate multiple oncogenic signaling pathways, including STAT3, SRC, and ERK. The objective of this study was to generate ovarian cancer cells with genetically depleted PTP4A3; to assess their tumorigenicity; to examine their cellular phenotype; and to uncover changes in their intracellular signaling pathways and cytokine release profiles. Genetic deletion of PTP4A3 using CRISPR/Cas9 enabled the generation of individual clones derived from single cells isolated from the polyclonal knockout population. We observed a >90% depletion of PTP4A3 protein levels by Western blotting in the clonal cell lines compared to the sham transfected wildtype population. The wildtype and polyclonal knockout cell lines shared similar monolayer growth rates, while the isolated clonal populations 2B4, 3C9, and 3C12 exhibited significantly lower monolayer growth characteristics consistent with their lower PTP4A3 levels. The clonal PTP4A3 knockout cell lines also had substantially lower in vitro colony formation efficiencies compared to the wildtype cells and were less tumorigenic in vivo The clonal knockout cells were markedly less responsive to IL-6-stimulated migration in a scratch wound assay compared to the wildtype cells. Antibody microarray assays documented differences in cytokine release and intracellular phosphorylation patterns in the PTP4A3 deleted clones. Bioinformatic network analyses indicated alterations in cellular signaling nodes. These biochemical changes could ultimately form the foundation for pharmacodynamic endpoints useful for emerging anti-PTP4A3 therapeutics. Significance Statement Clones of high grade serous ovarian cancer cells were isolated in which the oncogenic phosphatase PTP4A3 was deleted using CRISPR/Cas9 methodologies. The PTP4A3 null cells exhibited loss of in vitro proliferation, colony formation, and migration, and reduced in vivo tumorigenesis. Marked differences in intracellular protein phosphorylation and cytokine release were seen. The newly developed PTP4A3 knockout cells should provide useful tools to probe the role of PTP4A3 phosphatase in ovarian cancer cell survival, tumorigenicity and cell signaling.

Exploring the prevalence of antidepressant medication discontinuation among pregnant veterans.

US female veterans have higher rates of mental health (MH) disorders compared to US civilian females and, consequently, are at risk for poor MH outcomes during pregnancy. This study evaluated the MH burden and identified the prevalence of antidepressant prescription and discontinuation among pregnant veterans (PGVets). The electronic health records (EHR) of PGVets using the US Veterans Administration's (VA) maternity care benefits over a two-year period were retrospectively reviewed. Inclusion criteria for this study were a current MH diagnosis of depression, anxiety, or posttraumatic stress disorder (PTSD) at the onset of pregnancy (n=351). Outcomes examined included antidepressant use prior to pregnancy, the use and discontinuation of antidepressants during pregnancy, and risk factors for discontinuation. PGVets had a high MH burden, as indicated by multiple comorbid diagnoses of unipolar depression, anxiety, and PTSD in 67% of the sample. At the onset of pregnancy, 163 (46%) were treated with an antidepressant. Only 56 (34%) continued using antidepressants through the pregnancy. Self-discontinuation (34%) and VA provider discontinuation (31%) of antidepressants were found. Among PGVets with documented past suicidal behaviors, 90% discontinued their active antidepressants. PGVets with indicators for more severe MH diagnoses were most likely to discontinue. The MH burden of PGVets and high rates of antidepressant discontinuation have implications for engaging this population in a higher level of perinatal monitoring and intervention. The findings suggest that VA providers and veterans would benefit from risks and benefits education regarding antidepressant use during pregnancy as well as the provision of alternative therapies.

Perceived Benefits and Barriers of mHealth Mindfulness Use for Caregivers of Older Adults with Cognitive Impairment: A Qualitative Exploration.

OBJECTIVES: Mobile (mHealth) mindfulness-based interventions have the potential to be feasible, acceptable, effective, and scalable interventions for caregivers of people living with cognitive impairment. This qualitative study of caregivers of older adults with cognitive impairment explored caregivers' experiences using a mindfulness therapy mobile application. METHODS: Fifteen caregivers were interviewed using a semi-structured interview guide. Analysis was guided by the phenomenological approach and inductive-deductive analysis. RESULTS: Six themes were generated from the data: convenience, barriers, perceived helpfulness, useful features, suggested app improvements, and skill transfer. Caregivers reported that the app was easy to use with many perceived benefits. Caregivers also noted some barriers to using the app. CONCLUSIONS: This study revealed that self-directed mHealth delivered mindfulness therapy may be a promising intervention for the caregivers involved in the study. Having the ability to use the app anywhere and at any time was a prominent reason for continued regular use for the participants. This was especially important to some caregivers during the COVID-19 pandemic. The barriers discussed by the caregivers are important considerations for future app-based interventions for caregivers. CLINICAL IMPLICATIONS: Clinicians can consider recommending mHealth mindfulness therapy to caregivers as a tool to provide caregivers with additional support.

Pharmacological profiling identifies divergent chemosensitivities of differentiating and maturing iPSC-derived human cortical neuron populations.

Neuronal differentiation and maturation are extended developmental processes. To determine whether neurons at different developmental stages have divergent chemosensitivities, we screened differentiating and maturing neuronal populations using a small compound library comprising FDA-approved and investigational drugs. Using a neurotoxicity assay format, both respective neuronal population-based screening campaigns performed robustly (Z-factors = 0.7-0.8), although the hit rate for the differentiating neurons (2.8%) was slightly higher than for maturing neurons (1.9%). While the majority of hits were toxic to both neuronal populations, these hits predominantly represented promiscuous drugs. Other drugs were selectively neurotoxic, with receptor tyrosine kinase inhibitors disproportionally represented after confirmation. Ponatinib and amuvatinib were neuroinhibitory for differentiating and maturing neurons, respectively. Chemoinformatic analyses confirmed differences in potential drug targets that may be differentially expressed during neuronal development. Subsequent studies demonstrated neuronal expression of AXL, an amuvatinib target, in both neuronal populations. However, functional AXL activity was confirmed only in the maturing neuronal population as determined by AXL phosphorylation in response to GAS6, the cognate ligand of AXL, and concurrent STAT3Y705 phosphorylation. Differentiating neurons were unresponsive to the effects of GAS6 suggesting that the AXL-STAT3 signaling axis was nonfunctional. Amuvatinib treatment of maturing neuronal cultures significantly reduced pAXL levels. These studies indicate that neuronal developmental states may exhibit unique chemosensitivities and that drugs may have different neuro-inhibitory effects depending upon the developmental stage of the neuronal population.

Disruption of Ovarian Cancer STAT3 and p38 Signaling with a Small-Molecule Inhibitor of PTP4A3 Phosphatase.

Protein tyrosine phosphatase type IVA member 3 (PTP4A3 or PRL-3) is a nonreceptor, oncogenic, dual-specificity phosphatase that is highly expressed in many human tumors, including ovarian cancer, and is associated with a poor patient prognosis. Recent studies suggest that PTP4A3 directly dephosphorylates SHP-2 phosphatase as part of a STAT3-PTP4A3 feedforward loop and directly dephosphorylates p38 kinase. The goal of the current study was to examine the effect of a PTP4A phosphatase inhibitor, 7-imino-2-phenylthieno[3,2-c]pyridine-4,6(5H,7H)-dione (JMS-053), on ovarian cancer STAT3, SHP-2, and p38 kinase phosphorylation. JMS-053 caused a concentration- and time-dependent decrease in the activated form of STAT3, Y705 phospho-STAT3, in ovarian cancer cells treated in vitro. In contrast, the phosphorylation status of two previously described direct PTP4A3 substrates, SHP-2 phosphatase and p38 kinase, were rapidly increased with JMS-053 treatment. We generated A2780 and OVCAR4 ovarian cancer cells resistant to JMS-053, and the resulting cells were not crossresistant to paclitaxel, cisplatin, or teniposide. JMS-053-resistant A2780 and OVCAR4 cells exhibited a 95% and 50% decrease in basal Y705 phospho-STAT3, respectively. JMS-053-resistant OVCAR4 cells had an attenuated phosphorylation and migratory response to acute exposure to JMS-053. These results support a regulatory role for PTP4A phosphatase in ovarian cancer cell STAT3 and p38 signaling circuits. SIGNIFICANCE STATEMENT: This study demonstrates that chemical inhibition of PTP4A phosphatase activity with JMS-053 decreases STAT3 activation and increases SHP-2 phosphatase and p38 kinase phosphorylation activation in ovarian cancer cells. The newly developed JMS-053-resistant ovarian cancer cells should provide useful tools to further probe the role of PTP4A phosphatase in ovarian cancer cell survival and cell signaling.

A Health Inequity: Associations Between Cigarette Smoking Status and Mammogram Screening Among Women of Color.

INTRODUCTION: We evaluated differences in yearly mammogram screening by smoking status in a sample of US women. We also examined differences in mammogram screening by race/ethnicity, age, and health care coverage. METHODS: Data were from 1884 women participants in the 2018 Health of Houston Survey study. Binary logistic regression was used to assess the association between smoking status (current/former/non-smokers) and mammograms within 12 months. Moderators included race/ethnicity (Hispanic, Black, Asian, Other, White), age, and health care coverage. RESULTS: In comparison to women who were non-smokers, current and former smokers showed lower odds to get a yearly mammogram (OR = 0.720; 95% CI = 0.709, .730 and OR = 0.702; 95% CI = 0.693, 0.710, respectively). Current smokers who identified as Hispanic or Black women and former smokers who identified as Hispanic, Asian, and other women showed lower odds of getting a mammogram (OR = 0.635, 95% CI = 0.611, 0.659; OR = 0.951, 95% CI = 0.919, 0.985) and (OR = 0.663, 95% CI = 0.642, 0.684; OR = 0.282, 95% CI = 0.263, 0.302; OR = 0.548, 95% CI = 0.496, 0.606) compared to White women. There were significant interactions by age and health care coverage. CONCLUSIONS: Women of color who are current and former smokers showed lower odds to engage in mammogram screening, thus increasing their risk of undiagnosed breast cancer when compared to non-smokers. Ethnically diverse women already experience increased health disparities and smoking puts them at exacerbated risk of health complications and death. IMPLICATIONS: Our findings suggest that smoking status is a modifiable behavioral risk factor that requires further attention in the prevention of breast cancer in ethnic minority women. Health care institutions and policymakers need to increase their awareness of and outreach efforts to women of color who smoke. These outreach efforts should focus on increasing access to smoking interventions and cancer screenings.

High content screening miniaturization and single cell imaging of mature human feeder layer-free iPSC-derived neurons.

Human induced pluripotent stem cell (iPSC)-derived neurons are being increasingly used for high content imaging and screening. However, iPSC-derived neuronal differentiation and maturation is time-intensive, often requiring >8 weeks. Unfortunately, the differentiating and maturing iPSC-derived neuronal cultures also tend to migrate and coalesce into ganglion-like clusters making single-cell analysis challenging, especially in miniaturized formats. Using our defined extracellular matrix and low oxygen culturing conditions for the differentiation and maturation of human cortical neurons, we further modified neuronal progenitor cell seeding densities and feeder layer-free culturing conditions in miniaturized formats (i.e., 96 well) to decrease neuronal clustering, enhance single-cell identification and reduce edge effects usually observed after extended neuronal cell culture. Subsequent algorithm development refined capabilities to distinguish and identify single mature neurons, as identified by NeuN expression, from large cellular aggregates, which were excluded from image analysis. Incorporation of astrocyte conditioned medium during differentiation and maturation periods significantly increased the percentage (i.e., ∼10% to ∼30%) of mature neurons (i.e., NeuN+) detected at 4-weeks post-differentiation. Pilot, proof of concept studies using this optimized assay system yielded negligible edge effects and robust Z-factors in population-based as well as image-based neurotoxicity assay formats. Moreover, moxidectin, an FDA-approved drug with documented neurotoxic adverse effects, was identified as a hit using both screening formats. This miniaturized, feeder layer-free format and image analysis algorithm provides a foundational imaging and screening platform, which enables quantitative single-cell analysis of differentiated human neurons.

Platinum Chemotherapy Induces Lymphangiogenesis in Cancerous and Healthy Tissues That Can be Prevented With Adjuvant Anti-VEGFR3 Therapy.

Chemotherapy has been used to inhibit cancer growth for decades, but emerging evidence shows it can affect the tumor stroma, unintentionally promoting cancer malignancy. After treatment of primary tumors, remaining drugs drain via lymphatics. Though all drugs interact with the lymphatics, we know little of their impact on them. Here, we show a previously unknown effect of platinums, a widely used class of chemotherapeutics, to directly induce systemic lymphangiogenesis and activation. These changes are dose-dependent, long-lasting, and occur in healthy and cancerous tissue in multiple mouse models of breast cancer. We found similar effects in human ovarian and breast cancer patients whose treatment regimens included platinums. Carboplatin treatment of healthy mice prior to mammary tumor inoculation increased cancer metastasis as compared to no pre-treatment. These platinum-induced phenomena could be blocked by VEGFR3 inhibition. These findings have implications for cancer patients receiving platinums and may support the inclusion of anti-VEGFR3 therapy into treatment regimens or differential design of treatment regimens to alter these potential effects.

Older patients' and their caregivers' understanding of advanced care planning.

PURPOSE OF REVIEW: The aim of this study was to review the recent literature (2019-2021) on older patients' and their caregivers' understanding of advance care planning. RECENT FINDINGS: Recent studies highlight the continued gaps in knowledge about advance care planning for older adults with cancer and their caregivers both domestically and abroad. The recent literature also revealed that there is a lack of research methodology to assess knowledge of advance care planning reliably and validly in older adults with cancer and their caregivers given the lack of uniform scales to measure knowledge of advance care planning. SUMMARY: Older adults with cancer are at an elevated risk of death from their illness, and it is essential they understand how advance care planning can improve their quality of life, facilitate goal congruent care and ultimately decrease medical expenditures at end of life. In order to engage in a process such as advance care planning, patients must know what it is and how it can be helpful to them. The lack of understanding about advance care planning presents a significant barrier to patients engaging in the process. Public health campaigns to increase advance care planning knowledge are needed to ensure that older adults with cancer and their caregivers understand how this service can be helpful to them as they approach end of life.

The feasibility, acceptability, and preliminary efficacy of an mHealth mindfulness therapy for caregivers of adults with cognitive impairment.

Objectives: To examine the feasibility, acceptability, and preliminary efficacy of Mindfulness Coach, an mHealth Mindfulness Therapy intervention.Methods: We recruited 58 informal caregivers of older adults with cognitive impairment for this pilot feasibility trial. Participants completed measures of caregiver burden, stress, anxiety, and depression at baseline, 2 weeks, 4 weeks, and 8 weeks as well as acceptability and usability data at 8-weeks. The mobile app collected in-app use data including minutes spent using the app and number of unique visits to the app.Results: Users found the app acceptable to use and were satisfied with its design and usability. Over the course of the study period, depression, anxiety, caregiver burden and perceived stress improved. These outcome variables also improved more as caregivers spent more time using the Mindfulness Therapy mHealth intervention.Conclusions: Our results suggest that mHealth mindfulness therapy with caregivers of older adults with cognitive impairment is both feasible and acceptable to users, and that it successfully reduces psychological symptoms. Future work should focus on determining the appropriate doses of the mHealth therapy for particular outcomes and strategies to integrate it into routine care. Mindfulness Therapy delivered in an mHealth format may increase access to psychological treatment for caregivers.

CX-5461 Treatment Leads to Cytosolic DNA-Mediated STING Activation in Ovarian Cancer.

Epithelial ovarian cancer (EOC) is the deadliest of the gynecologic malignancies, with an overall survival rate of <30%. Recent research has suggested that targeting RNA polymerase I (POL I) with small-molecule inhibitors may be a viable therapeutic approach to combating EOC, even when chemoresistance is present. CX-5461 is one of the most promising POL I inhibitors currently being investigated, and previous reports have shown that CX-5461 treatment induces DNA damage response (DDR) through ATM/ATR kinase. Investigation into downstream effects of CX-5461 led us to uncovering a previously unreported phenotype. Treatment with CX-5461 induces a rapid accumulation of cytosolic DNA. This accumulation leads to transcriptional upregulation of 'STimulator of Interferon Genes' (STING) in the same time frame, phosphorylation of IRF3, and activation of type I interferon response both in vitro and in vivo. This activation is mediated and dependent on cyclic GMP-AMP synthase (cGAS). Here, we show THAT CX-5461 leads to an accumulation of cytosolic dsDNA and thereby activates the cGAS-STING-TBK1-IRF3 innate immune pathway, which induces type I IFN. CX-5461 treatment-mediated immune activation may be a powerful mechanism of action to exploit, leading to novel drug combinations with a chance of increasing immunotherapy efficacy, possibly with some cancer specificity limiting deleterious toxicities.

Credentialing and Pharmacologically Targeting PTP4A3 Phosphatase as a Molecular Target for Ovarian Cancer.

High grade serous ovarian cancer (OvCa) frequently becomes drug resistant and often recurs. Consequently, new drug targets and therapies are needed. Bioinformatics-based studies uncovered a relationship between high Protein Tyrosine Phosphatase of Regenerating Liver-3 (PRL3 also known as PTP4A3) expression and poor patient survival in both early and late stage OvCa. PTP4A3 mRNA levels were 5-20 fold higher in drug resistant or high grade serous OvCa cell lines compared to nonmalignant cells. JMS-053 is a potent allosteric small molecule PTP4A3 inhibitor and to explore further the role of PTP4A3 in OvCa, we synthesized and interrogated a series of JMS-053-based analogs in OvCa cell line-based phenotypic assays. While the JMS-053 analogs inhibit in vitro PTP4A3 enzyme activity, none were superior to JMS-053 in reducing high grade serous OvCa cell survival. Because PTP4A3 controls cell migration, we interrogated the effect of JMS-053 on this cancer-relevant process. Both JMS-053 and CRISPR/Cas9 PTP4A3 depletion blocked cell migration. The inhibition caused by JMS-053 required the presence of PTP4A3. JMS-053 caused additive or synergistic in vitro cytotoxicity when combined with paclitaxel and reduced in vivo OvCa dissemination. These results indicate the importance of PTP4A3 in OvCa and support further investigations of the lead inhibitor, JMS-053.

Utilización de prácticas clínicas para promover la cesación tabáquica en personas que viven con VIH en Argentina / Use of smoking cessation clinical practices among persons living with HIV in Argentina

INTRODUCCIÓN: El consumo de tabaco en las personas que viven con VIH (PVV) en Argentina está entre un 40 y un 60%. El consumo de tabaco se relaciona con la aparición de cáncer en la población general y con una disminución de la respuesta al tratamiento antirretroviral en las PVV. Los médicos que atienden a las PVV pueden tener un papel fundamental en ayudar a sus pacientes a dejar de fumar. Este estudio examinó los factores relacionados con la utilización de las prácticas clínicas de cesación tabáquica en una muestra de médicos infectólogos que atienden a PVV en Argentina. MÉTODOS: Se administró una encuesta en línea a miembros de la Sociedad Argentina de Infectología, quienes referían atender a PVV. Se realizaron análisis descriptivos y modelos lineales generalizados. RESULTADOS: Participaron 138 profesionales (20,4% de los convocados). La implementación de métodos para la cesación tabáquica por los infectólogos fue significativamente mayor en aquellos profesionales que habían recibido educación al respecto (RPa: 1,22; IC 95%: 1,10-1,35), y disminuía significativamente en quienes no habían recibido entrenamiento formal (RPa: 0,64; IC 95%: 0,44-0,94). DISCUSIÓN: Hay necesidad de incorporar el entrenamiento en cesación tabáquica en la capacitación profesional de médicos que atienden a PVV para aumentar sus destrezas en estas prácticas clínicas y disminuir el consumo de tabaco en esta población

Mobile Applications for Advance Care Planning: A Comprehensive Review of Features, Quality, Content, and Readability.

Mobile applications that facilitate each stage of the advance care planning process (i.e., obtaining knowledge, contemplating options, and acting on decisions) may be one effective way to support patient-centered care and patient autonomy. The purpose of the current review was to identify and evaluate advance care planning mobile applications for patients. Our specific aim was to examine app features, design quality, content, and readability. We searched the Apple iOS and Google Play stores using keywords developed in conjunction with an academic librarian. Two coders with expertise in palliative care applied guidelines from a previous review and used a consensus coding procedure. We also calculated a Flesh Reading Ease score for each app. Nine apps met criteria and could be evaluated. Overall, apps are limited in features and poor in terms of design quality, layout, and functionality. Regarding content, most apps emphasize making decisions or taking action about advance care planning: 6 apps permit users to document a preferred decision maker, and 6 apps offer a mechanism to distribute and share advance care planning documentation. Three apps focus on knowledge about advance care planning, and only 4 support contemplation about advance care planning. Apps range in terms of readability, from very difficult to fairly easy. This review identifies limitations in features, design quality, and content of existing advance care planning mobile apps. We present recommendations based on the results of this review for the development of future advance care planning apps.

Central Actions of 3α,5α-THP Involving NMDA and GABAA Receptors Regulate Affective and Sexual Behavior of Female Rats.

The neurosteroid, 5α-pregnan-3α-ol-20-one (known as "allopregnanolone" or 3α,5α-THP), is produced in the midbrain ventral tegmental area (VTA), independent of peripheral sources of progestogens, where it has potential actions at N-methyl-D-aspartate (NMDA) and GABAA receptors to facilitate rodent sexual behavior. Progestogens can also have anti-anxiety effects, but whether these involve actions of centrally-derived 3α,5α-THP or these receptors to support reproductively-relevant behavior is not well understood. We investigated the extent to which 3α,5α-THP's actions via NMDA and/or GABAA receptors in the midbrain VTA influence reproductive behaviors. Estradiol-primed, ovariectomized/adrenalectomized (OVX/ADX) rats received midbrain VTA infusions of vehicle, an NMDA receptor blocker (MK-801; 200 ng), or a GABAA receptor blocker (bicuculline; 100 ng) followed by a second infusion of vehicle or 3α,5α-THP (100 ng). Reproductively-relevant behaviors were assessed: sexual (paced mating), anxiety-like (elevated plus maze), and social (partner preference, social interaction) behavior. Compared to vehicle, intra-VTA infusions of MK-801 exerted anxiolytic-like effects on elevated plus maze behavior and enhanced lordosis. Unlike prior observations in gonadally-intact rats, intra-VTA bicuculline had no effect on the behavior of OVX/ADX rats (likely due to a floor effect). Subsequent infusions of 3α,5α-THP reversed effects on lordosis and infusions of bicuculline inhibited 3α,5α-THP-facilitated lordosis. Thus, NMDA and GABAA receptors may act as mediators for reproductive behavioral effects of 3α,5α-THP in the midbrain VTA.

A Single-Agent Dual-Specificity Targeting of FOLR1 and DR5 as an Effective Strategy for Ovarian Cancer.

Therapeutic antibodies targeting ovarian cancer (OvCa)-enriched receptors have largely been disappointing due to limited tumor-specific antibody-dependent cellular cytotoxicity. Here we report a symbiotic approach that is highly selective and superior compared with investigational clinical antibodies. This bispecific-anchored cytotoxicity activator antibody is rationally designed to instigate "cis" and "trans" cytotoxicity by combining specificities against folate receptor alpha-1 (FOLR1) and death receptor 5 (DR5). Whereas the in vivo agonist DR5 signaling requires FcγRIIB interaction, the FOLR1 anchor functions as a primary clustering point to retain and maintain a high level of tumor-specific apoptosis. The presented proof of concept study strategically makes use of a tumor cell-enriched anchor receptor for agonist death receptor targeting to potentially generate a clinically viable strategy for OvCa.

Targeting ovarian cancer and endothelium with an allosteric PTP4A3 phosphatase inhibitor.

Overexpression of protein tyrosine phosphatase PTP4A oncoproteins is common in many human cancers and is associated with poor patient prognosis and survival. We observed elevated levels of PTP4A3 phosphatase in 79% of human ovarian tumor samples, with significant overexpression in tumor endothelium and pericytes. Furthermore, PTP4A phosphatases appear to regulate several key malignant processes, such as invasion, migration, and angiogenesis, suggesting a pivotal regulatory role in cancer and endothelial signaling pathways. While phosphatases are attractive therapeutic targets, they have been poorly investigated because of a lack of potent and selective chemical probes. In this study, we disclose that a potent, selective, reversible, and noncompetitive PTP4A inhibitor, JMS-053, markedly enhanced microvascular barrier function after exposure of endothelial cells to vascular endothelial growth factor or lipopolysaccharide. JMS-053 also blocked the concomitant increase in RhoA activation and loss of Rac1. In human ovarian cancer cells, JMS-053 impeded migration, disrupted spheroid growth, and decreased RhoA activity. Importantly, JMS-053 displayed anticancer activity in a murine xenograft model of drug resistant human ovarian cancer. These data demonstrate that PTP4A phosphatases can be targeted in both endothelial and ovarian cancer cells, and confirm that RhoA signaling cascades are regulated by the PTP4A family.

Small molecule inhibition of the CBFß/RUNX interaction decreases ovarian cancer growth and migration through alterations in genes related to epithelial-to-mesenchymal transition.

OBJECTIVE: Ovarian cancer survival and treatment have improved minimally in the past 20years. Novel treatment strategies are needed to combat this disease. This study investigates the effects of chemical inhibition of the CBFß/RUNX protein-protein interaction on ovarian cancer cell lines. METHODS: Ovarian cancer cell lines were treated with CBFß/RUNX inhibitors, and the effects on proliferation, DNA replication, wound healing, and anchorage-independent growth were measured. RNA-Seq was performed on compound-treated cells to identify differentially expressed genes. Genes altered by compound treatment were targeted with siRNAs, and effects on DNA replication and wound healing were measured. RESULTS: Chemical inhibition of the CBFß/RUNX interaction decreases ovarian cancer cell proliferation. Inhibitor treatment leads to an S-phase cell cycle delay, as indicated by an increased percentage of cells in S-phase, and a decreased DNA replication rate. Inhibitor treatment also reduces wound healing and anchorage-independent growth. RNA-Seq on compound-treated cells revealed changes in a small number of genes related to proliferation and epithelial-to-mesenchymal transition. siRNA-mediated knockdown of INHBA and MMP1 - two genes whose expression decreases with compound treatment - slowed DNA replication and impaired wound healing. CONCLUSIONS: Chemical inhibition of the CBFß/RUNX interaction is a viable strategy for the treatment of ovarian cancer.

Emerging Therapeutics to Overcome Chemoresistance in Epithelial Ovarian Cancer: A Mini-Review.

Ovarian cancer is the fifth leading cause of cancer death among women and the most lethal gynecologic malignancy. One of the leading causes of death in high-grade serous ovarian cancer (HGSOC) is chemoresistant disease, which may present as intrinsic or acquired resistance to therapies. Here we discuss some of the known molecular mechanisms of chemoresistance that have been exhaustively investigated in chemoresistant ovarian cancer, including drug efflux pump multidrug resistance protein 1 (MDR1), the epithelial-mesenchymal transition, DNA damage and repair capacity. We also discuss novel therapeutics that may address some of the challenges in bringing approaches that target chemoresistant processes from bench to bedside. Some of these new therapies include novel drug delivery systems, targets that may halt adaptive changes in the tumor, exploitation of tumor mutations that leave cancer cells vulnerable to irreversible damage, and novel drugs that target ribosomal biogenesis, a process that may be uniquely different in cancer versus non-cancerous cells. Each of these approaches, or a combination of them, may provide a greater number of positive outcomes for a broader population of HGSOC patients.

Targeting RNA-Polymerase I in Both Chemosensitive and Chemoresistant Populations in Epithelial Ovarian Cancer.

Purpose: A hallmark of neoplasia is increased ribosome biogenesis, and targeting this process with RNA polymerase I (Pol I) inhibitors has shown some efficacy. We examined the contribution and potential targeting of ribosomal machinery in chemotherapy-resistant and -sensitive models of ovarian cancer.Experimental Design: Pol I machinery expression was examined, and subsequently targeted with the Pol I inhibitor CX-5461, in ovarian cancer cell lines, an immortalized surface epithelial line, and patient-derived xenograft (PDX) models with and without chemotherapy. Effects on viability, Pol I occupancy of rDNA, ribosomal content, and chemosensitivity were examined.Results: In PDX models, ribosomal machinery components were increased in chemotherapy-treated tumors compared with controls. Thirteen cell lines were sensitive to CX-5461, with IC50s 25 nmol/L-2 µmol/L. Interestingly, two chemoresistant lines were 10.5- and 5.5-fold more sensitive than parental lines. CX-5461 induced DNA damage checkpoint activation and G2-M arrest with increased γH2AX staining. Chemoresistant cells had 2- to 4-fold increased rDNA Pol I occupancy and increased rRNA synthesis, despite having slower proliferation rates, whereas ribosome abundance and translational efficiency were not impaired. In five PDX models treated with CX-5461, one showed a complete response, one a 55% reduction in tumor volume, and one maintained stable disease for 45 days.Conclusions: Pol I inhibition with CX-5461 shows high activity in ovarian cancer cell lines and PDX models, with an enhanced effect on chemoresistant cells. Effects occur independent of proliferation rates or dormancy. This represents a novel therapeutic approach that may have preferential activity in chemoresistant populations. Clin Cancer Res; 23(21); 6529-40. ©2017 AACR.