Hypertensive disorders of pregnancy among women with a history of leukemia or lymphoma.

OBJECTIVE: Hypertension during pregnancy can adversely affect maternal and fetal health. This study assessed whether diagnosis of leukemia or lymphoma prior to pregnancy is associated with hypertensive disorders of pregnancy including gestational hypertension, preeclampsia and eclampsia. STUDY DESIGN: A cross-sectional study used two statewide population-based datasets that linked birth certificates with sources of maternal medical history: hospital discharges in California and Surveillance, Epidemiology, and End Results (SEER) cancer registry data in Iowa. Birth years included 2007-2012 in California and 1989-2018 in Iowa. MAIN OUTCOME MEASURES: Primary outcome measure was hypertension in pregnancy measured from combined birth certificate and hospital diagnoses in California (for gestational hypertension, preeclampsia, or eclampsia) and birth certificate information (gestational hypertension or eclampsia) in Iowa. RESULTS: After adjusting for maternal age, race, education, smoking, and plurality, those with a history of leukemia/lymphoma were at increased risk of hypertensive disorders of pregnancy in Iowa (odds ratio (OR) = 1.86; 95% CI 1.07-3.23), but not in California (OR = 1.12; 95% CI 0.87-1.43). In sensitivity analysis restricting to more severe forms of hypertension in pregnancy (preeclampsia and eclampsia) in the California cohort, the effect estimate increased (OR = 1.29; 95% CI 0.96-1.74). CONCLUSION: In a population-based linked cancer registry-birth certificate study, an increased risk of hypertensive disorders of pregnancy was observed among leukemia or lymphoma survivors. Findings were consistent but non-significant in a second, more ethnically diverse study population with less precise cancer history data. Improved monitoring and surveillance may be warranted for leukemia or lymphoma survivors throughout their pregnancies.

Inhibitor of DNA binding 2 (ID2) regulates the expression of developmental genes and tumorigenesis in ewing sarcoma.

Sarcomas are difficult to treat and the therapy, even when effective, is associated with long-term and life-threatening side effects. In addition, the treatment regimens for many sarcomas, including Ewing sarcoma, rhabdomyosarcoma, and osteosarcoma, are relatively unchanged over the past two decades, indicating a critical lack of progress. Although differentiation-based therapies are used for the treatment of some cancers, the application of this approach to sarcomas has proven challenging. Here, using a CRISPR-mediated gene knockout approach, we show that Inhibitor of DNA Binding 2 (ID2) is a critical regulator of developmental-related genes and tumor growth in vitro and in vivo in Ewing sarcoma tumors. We also identified that homoharringtonine, which is an inhibitor of protein translation and FDA-approved for the treatment of leukemia, decreases the level of the ID2 protein and significantly reduces tumor growth and prolongs mouse survival in an Ewing sarcoma xenograft model. Furthermore, in addition to targeting ID2, homoharringtonine also reduces the protein levels of ID1 and ID3, which are additional members of the ID family of proteins with well-described roles in tumorigenesis, in multiple types of cancer. Overall, these results provide insight into developmental regulation in Ewing sarcoma tumors and identify a novel, therapeutic approach to target the ID family of proteins using an FDA-approved drug.

The risk of preterm birth among women with a history of leukemia or lymphoma.

OBJECTIVE: Leukemia and lymphoma are top cancers affecting children, adolescents and young adults with high five-year survival rates. Late effects of these cancers are a concern in reproductive-age patients, including pregnancy outcomes such as preterm birth. Our study aimed to evaluate whether diagnosis of leukemia or lymphoma prior to pregnancy was associated with preterm birth (<37 weeks gestation). METHODS: We conducted a cross-sectional study using a population-based dataset from California with linked birth certificates to hospital discharge records and an Iowa-based sample that linked birth certificates to Surveillance, Epidemiology, and End Results (SEER) cancer registry data. Preterm birth was defined using birth certificates. We ascertained history of leukemia and lymphoma using discharge diagnosis data in California and SEER registry in Iowa. RESULTS: Prevalence of preterm birth in California and Iowa was 14.6% and 12.0%, respectively, in women with a history of leukemia/lymphoma compared to 7.8% and 8.2%, respectively, in women without a cancer history. After adjusting for maternal age, race, education, smoking, and plurality, Women with history of leukemia/lymphoma were at an increased risk of having a preterm birth in California (odds ratio (OR) 1.89; 95% confidence interval (CI) 1.56-2.28) and Iowa (OR 1.61; 95% CI 1.10-2.37) compared to those with no cancer history. CONCLUSION: In both California and Iowa, women with a history of leukemia or lymphoma were at increased risk for preterm birth. This suggests the importance of counseling with a history of leukemia/lymphoma prior to pregnancy and increased monitoring of women during pregnancy.

Metabolic differences among newborns born to mothers with a history of leukemia or lymphoma.

BACKGROUND: Leukemia and lymphoma are cancers affecting children, adolescents, and young adults and may affect reproductive outcomes and maternal metabolism. We evaluated for metabolic changes in newborns of mothers with a history of these cancers. METHODS: A cross-sectional study was conducted on California births from 2007 to 2011 with linked maternal hospital discharge records, birth certificate, and newborn screening metabolites. History of leukemia or lymphoma was determined using ICD-9-CM codes from hospital discharge data and newborn metabolite data from the newborn screening program. RESULTS: A total of 2,068,038 women without cancer history and 906 with history of leukemia or lymphoma were included. After adjusting for differences in maternal age, infant sex, age at metabolite collection, gestational age, and birthweight, among newborns born to women with history of leukemia/lymphoma, several acylcarnitines were significantly (p < .001 - based on Bonferroni correction for multiple testing) higher compared to newborns of mothers without cancer history: C3-DC (mean difference (MD) = 0.006), C5-DC (MD = 0.009), C8:1 (MD = 0.008), C14 (MD = 0.010), and C16:1 (MD = 0.011), whereas citrulline levels were significantly lower (MD = -0.581) among newborns born to mothers with history of leukemia or lymphoma compared to newborns of mothers without a history of cancer. CONCLUSION: The varied metabolite levels suggest history of leukemia or lymphoma has metabolic impact on newborn offspring, which may have implications for future metabolic consequences such as necrotizing enterocolitis and urea cycle enzyme disorders in children born to mothers with a history of leukemia or lymphoma.

The translational repressor 4E-BP1 regulates RRM2 levels and functions as a tumor suppressor in Ewing sarcoma tumors.

Ribonucleotide reductase (RNR), which is a heterodimeric tetramer composed of RRM1 and RRM2 subunits, is the rate-limiting enzyme in the synthesis of deoxyribonucleoside triphosphates (dNTPs) and essential for both DNA replication and the repair of DNA damage. The activity of RNR is coordinated with the cell cycle and regulated by fluctuations in the level of the RRM2 subunit. Multiple cancer types, including Ewing sarcoma tumors, are sensitive to inhibitors of RNR or a reduction in the levels of either the RRM1 or RRM2 subunits of RNR. Here, we show that the expression of the RRM2 protein is dependent on active protein synthesis and that 4E-BP1, a repressor of cap-dependent protein translation, specifically regulates the level of the RRM2 protein. Furthermore, inhibition of mTORC1/2, but not mTORC1, activates 4E-BP1, inhibits protein synthesis, and reduces the level of the RRM2 protein in multiple sarcoma cell lines. This effect of mTORC1/2 inhibitors on protein synthesis and RRM2 levels was rescued in cell lines with the CRISPR/Cas9-mediated knockout of 4E-BP1. In addition, the inducible expression of a mutant 4E-BP1 protein that cannot be phosphorylated by mTOR blocked protein synthesis and inhibited the growth of Ewing sarcoma cells in vitro and in vivo in a xenograft. Overall, these results provide insight into the multifaceted regulation of RRM2 protein levels and identify a regulatory link between protein translation and DNA replication.

Eltrombopag inhibits the proliferation of Ewing sarcoma cells via iron chelation and impaired DNA replication.

BACKGROUND: The treatment of Ewing sarcoma, an aggressive bone and soft tissue sarcoma, is associated with suboptimal outcomes and significant side-effects. Consequently, there is an urgent need to identify novel therapies that will improve outcomes for children and adults with Ewing sarcoma tumors while also decreasing treatment-related toxicities. METHODS: We analyzed data from the PRISM drug repurposing screen, which tested the activity of 4518 drugs across 578 cancer cell lines, to identify drugs that selectively inhibit the growth of Ewing sarcoma cell lines. We then tested the effects of a top hit from the screen on cell proliferation, cell cycle progression, and activation of the DNA damage pathway using Ewing sarcoma cell lines. We also used a CRISPR/Cas9 gene knockout approach to investigate the role of Schlafen 11 (SLFN11), a restriction factor for DNA replication stress that is overexpressed in Ewing sarcoma tumors, in mediating the sensitivity of Ewing sarcoma cells to the drug. RESULTS: We found that eltrombopag, an FDA-approved thrombopoietin-receptor agonist (TPO-RA) that is currently being evaluated as a treatment for chemotherapy-induced thrombocytopenia, inhibits the growth of Ewing sarcoma cell lines in vitro in proliferation and colony formation assays. However, from a mechanistic standpoint, the thrombopoietin receptor is not expressed in Ewing sarcoma cells and we show that eltrombopag impairs DNA replication and causes DNA damage in Ewing sarcoma cells by chelating iron, a known "off-target" effect of the drug. We also found that the sensitivity of Ewing sarcoma cells to eltrombopag is mediated, in part, by SLFN11, which regulates the cellular response to DNA replication stress. CONCLUSIONS: Ewing sarcoma cell lines are sensitive to eltrombopag and this drug could improve outcomes for patients with Ewing sarcoma tumors by both targeting the tumor, via chelation of iron and inhibition of DNA replication, and reducing chemotherapy-induced thrombocytopenia, via stimulation of the thrombopoietin receptor.

Inhibition of the ATR-CHK1 Pathway in Ewing Sarcoma Cells Causes DNA Damage and Apoptosis via the CDK2-Mediated Degradation of RRM2.

Inhibition of ribonucleotide reductase (RNR), the rate-limiting enzyme in the synthesis of deoxyribonucleotides, causes DNA replication stress and activates the ataxia telangiectasia and rad3-related protein (ATR)-checkpoint kinase 1 (CHK1) pathway. Notably, a number of different cancers, including Ewing sarcoma tumors, are sensitive to the combination of RNR and ATR-CHK1 inhibitors. However, multiple, overlapping mechanisms are reported to underlie the toxicity of ATR-CHK1 inhibitors, both as single agents and in combination with RNR inhibitors, toward cancer cells. Here, we identified a feedback loop in Ewing sarcoma cells in which inhibition of the ATR-CHK1 pathway depletes RRM2, the small subunit of RNR, and exacerbates the DNA replication stress and DNA damage caused by RNR inhibitors. Mechanistically, we identified that the inhibition of ATR-CHK1 activates CDK2, which targets RRM2 for degradation via the proteasome. Similarly, activation of CDK2 by inhibition or knockdown of the WEE1 kinase also depletes RRM2 and causes DNA damage and apoptosis. Moreover, we show that the concurrent inhibition of ATR and WEE1 has a synergistic effect in Ewing sarcoma cells. Overall, our results provide novel insight into the response to DNA replication stress, as well as a rationale for targeting the ATR, CHK1, and WEE1 pathways, in Ewing sarcoma tumors. IMPLICATIONS: Targeting the ATR, CHK1, and WEE1 kinases in Ewing sarcoma cells activates CDK2 and increases DNA replication stress by promoting the proteasome-mediated degradation of RRM2.

Factors Impacting Fertility Preservation in Adolescents and Young Adults with Cancer: A Retrospective Study.

Purpose: Fertility preservation before therapy is underutilized for those diagnosed with cancer as an adolescent or young adult (AYA). The purpose of this study was to describe factors impacting utilization of fertility preservation consultations and procedures among AYAs at the University of Iowa Health Care (UIHC). Methods: Patients were identified by the oncology registry at UIHC. Disease site, histology, date of diagnosis, sex, race, ethnicity, insurance, and zip code data were gathered by the registrars. UIHC's electronic medical record was queried for fertility preservation consultation. The Reproductive Endocrinology and Infertility clinical database captured information about patients who underwent fertility preservation. Rural-urban commuting area codes measured rurality. Descriptive statistics and multivariate linear probability models were used to predict the probability of fertility preservation consultation and procedure. Results: From 2008 to 2017, 2932 AYAs were treated for an invasive malignancy at UIHC. Of the 440 (15%) who received a fertility preservation consultation, 156 (5%) underwent a fertility preservation procedure. Multivariate analyses showed that AYAs with public insurance coverage, those diagnosed with central nervous system (CNS) disease or melanoma, and those >30 years old at diagnosis had a significant decrease in the percentage point probability of having a consultation. The percentage point probability of undergoing a procedure was decreased for female patients, those with melanoma or carcinoma, those seen by a pediatric-based provider, and those diagnosed after 25 years of age. Conclusion: This study has important implications for practice and policy, particularly regarding insurance coverage and patient and provider characteristics leading to fertility preservation consultations and procedures for AYAs with cancer.

Novel Use of Porcine Urinary Bladder Matrix in the Exenterated Socket.

The aim of exenteration reconstruction is to stabilize the postsurgical wound bed to promote expeditious healing particularly in patients who are undergoing adjuvant radiation and/or chemotherapy. Porcine urinary bladder matrix has previously been used successfully as a wound-healing scaffold in treatment of burns and in acute, chronic, and surgical wounds, but the use of these products has not previously been reported in the exenterated orbit. The authors present a case of the novel use of porcine urinary bladder matrix in a pediatric patient who underwent exenteration for recurrent embryonal rhabdomyosarcoma, subsequent split-thickness skin grafting, and adjuvant radiation.

mTORC1/2 and Protein Translation Regulate Levels of CHK1 and the Sensitivity to CHK1 Inhibitors in Ewing Sarcoma Cells.

The treatment of Ewing sarcoma has changed very little in the past two decades and novel treatment approaches are needed. We recently identified that Ewing sarcoma cells are uniquely vulnerable to inhibitors of ribonucleotide reductase (RNR), the rate-limiting enzyme in the synthesis of deoxyribonucleotides. We subsequently found that the inhibition of checkpoint kinase 1 (CHK1) increases the sensitivity of Ewing sarcoma cells to inhibitors of RNR, such as gemcitabine. However, Ewing sarcoma cells exhibit high levels of the CHK1 protein, which may represent an adaptive response to elevated levels of endogenous DNA replication stress. Consequently, we began this work with the aim of determining the impact of CHK1 levels on drug sensitivity, as well as identifying the mechanisms and pathways that regulate CHK1 levels in Ewing sarcoma cells. In this report, we show that the high levels of the CHK1 protein in Ewing sarcoma cells limit the efficacy of CHK1 inhibitors. However, inhibition of mTORC1/2 activates the translational repressor 4E-BP1, reduces protein synthesis, and decreases levels of the CHK1 protein in Ewing sarcoma cells. Similarly, we identified that the CHK1 inhibitor prexasertib also activates 4E-BP1, inhibits protein synthesis, and reduces CHK1 protein levels in Ewing sarcoma cells. Moreover, the combination of prexasertib and gemcitabine was synergistic in vitro, caused tumor regression in vivo, and significantly prolonged mouse survival in a Ewing sarcoma xenograft experiment. Overall, our results provide insight into Ewing sarcoma biology and support further investigation of the CHK1 pathway as a therapeutic target in Ewing sarcoma tumors.

Identifying and Understanding the Gaps in Care Experienced by Adolescent and Young Adult Cancer Patients at the University of Iowa Hospitals and Clinics.

PURPOSE: In an effort to counteract the differences in improvement in survival rates of adolescents and young adults (AYA), compared to other age groups with cancer, the University of Iowa Hospitals and Clinics established an AYA cancer program. This study was conducted to gather feedback from AYAs in an effort to generate actionable data for program development. METHODS: The target population included patients aged 13-31 treated for malignancy in one of the following disease sites: central nervous system, leukemia, lymphoma, neuroendocrine, sarcoma, and thyroid. A series of four focus groups was held to identify and describe gaps in care and provide suggestions for program development. A convergent parallel mixed-methods design was used. Qualitative data were derived from focus group discussion and free-response survey questions, while quantitative data were derived from objective survey questions and electronic medical record data. RESULTS: Across the four focus groups, 24 different AYAs participated, ranging from 8 to 19 individuals per session. Topics discussed included the following: communication, treatment experience, and overall AYA program; finances, work and school, and late effects; relationships, emotions, and spirituality; and body image, infertility, sexuality, risky behavior, and suicide. The results of the analyses corroborated what makes AYAs different from other age groups. The primary theme identified was the unique relationships of AYAs, which can be thought of along a continuum. CONCLUSIONS: Information obtained from these analyses has been used to inform specific projects within the development of the AYA program to address patient-identified gaps. For AYAs, the importance of relationships along a continuum should be considered when developing an AYA program, in addition to potential policy or health service research utilization in the future.

Inhibition of CHK1 sensitizes Ewing sarcoma cells to the ribonucleotide reductase inhibitor gemcitabine.

Ewing sarcoma is a bone and soft tissue sarcoma that occurs in children and young adults. The EWS-FLI1 gene fusion is the driver mutation in most Ewing sarcoma tumors and functions, in part, as an aberrant transcription factor. We recently identified that Ewing sarcoma cells are sensitive to inhibition of ribonucleotide reductase (RNR), which catalyzes the formation of deoxyribonucleotides from ribonucleotides. In this report, we show that Ewing sarcoma cells are sensitive to treatment with clofarabine, which is a nucleoside analogue and allosteric inhibitor of RNR. However, clofarabine is a reversible inhibitor of RNR and we found that the effect of clofarabine is limited when using a short (6-hour) drug treatment. Gemcitabine, on the other hand, is an irreversible inhibitor of the RRM1 subunit of RNR and this drug induces apoptosis in Ewing sarcoma cells when used in both 6-hour and longer drug treatments. Treatment of Ewing sarcoma cells with gemcitabine also results in activation of checkpoint kinase 1 (CHK1), which is a critical mediator of cell survival in the setting of impaired DNA replication. Notably, inhibition of CHK1 function in Ewing sarcoma cells using a small-molecule CHK1 inhibitor, or siRNA knockdown, in combination with gemcitabine results in increased toxicity both in vitro and in vivo in a mouse xenograft experiment. Overall, our results provide insight into Ewing sarcoma biology and identify a candidate therapeutic target, and drug combination, in Ewing sarcoma.