The Lineage Determining Factor GRHL2 Collaborates with FOXA1 to Establish a Targetable Pathway in Endocrine Therapy-Resistant Breast Cancer.

Notwithstanding the positive clinical impact of endocrine therapies in estrogen receptor-alpha (ERα)-positive breast cancer, de novo and acquired resistance limits the therapeutic lifespan of existing drugs. Taking the position that resistance is nearly inevitable, we undertook a study to identify and exploit targetable vulnerabilities that were manifest in endocrine therapy-resistant disease. Using cellular and mouse models of endocrine therapy-sensitive and endocrine therapy-resistant breast cancer, together with contemporary discovery platforms, we identified a targetable pathway that is composed of the transcription factors FOXA1 and GRHL2, a coregulated target gene, the membrane receptor LYPD3, and the LYPD3 ligand, AGR2. Inhibition of the activity of this pathway using blocking antibodies directed against LYPD3 or AGR2 inhibits the growth of endocrine therapy-resistant tumors in mice, providing the rationale for near-term clinical development of humanized antibodies directed against these proteins.

Dysregulation of inflammatory cytokines and inhibition of VEGFA in the human umbilical cord are associated with negative pregnancy outcomes.

INTRODUCTION: Cytokines and vascular endothelial growth factors (VEGF) are involved in all aspects of pregnancy: from placentation, through fetal development, parturition and neonatal well-being. Umbilical cord inflammatory cytokines and/or VEGF have not been well studied with respect to dysregulation associated with disorders of pregnancy or maternal/neonatal outcomes. METHODS: Here we have used multiplex ELISA to screen umbilical cord lysates (comprising cord blood, endothelia and Wharton's jelly, n = 380), for levels of IFN-γ, IL1-ß, IL-6, IL-8, IL-10, TNF-α and VEGFs A, C and D and associations with 46 ICD9/10 codes encompassing obstetric, maternal and neonatal variables. RESULTS: No significant differences were observed for IFNγ, VEGFC or VEGFD with any clinical outcomes. The cytokines IL1-ß, IL-6, IL-8, IL-10, and TNF-α showed varying levels of induction and suppression with primarily fetal-placental and neonatal complications. The largest number of significant differences between umbilical cytokines and clinical outcomes were observed for chorioamnionitis (IL1-ß, IL-6, IL-8, TNF-α), and meconium passage during birth (IL1-ß, IL-6, IL-8) where significant pro-inflammatory responses occurred and sex differences in IL-8 expression were noted. In contrast, gonococcal infection showed suppressed immune response significantly lowering IL1-ß, IL-6, IL-8, IL-10 and TNF-α. For 12/46 negative pregnancy outcomes, strong suppression of VEGFA occurred. DISCUSSION: Angiogenic and inflammatory changes in the umbilical cord could be detrimental by increasing vascular permeability in the umbilical artery or vein and/or altering vascular tone, either of which would alter blood flow affecting delivery and removal of compounds. Further elucidation of inflammatory responses in the umbilical cord may provide mechanistic understanding of adverse pregnancy outcomes.

Opioid prescribing trends in postpartum women: a multicenter study.

BACKGROUND: The postpartum period can be a particularly vulnerable time for exposure to opioid medications, and there are currently no consensus guidelines for physicians to follow regarding opioid prescribing during this period. OBJECTIVE: The purpose of this study was to evaluate inter- and intrahospital variability in opioid prescribing patterns in postpartum women and better understand the role of clinical variables in prescribing. STUDY DESIGN: Data were extracted from electronic medical records on 4248 patients who delivered at 6 hospitals across the United States from January 2016 through March 2016. The primary outcome of the study was postpartum opioid prescription at the time of hospital discharge. Age, parity, route of delivery, and hospital were analyzed individually and with multivariate analyses to minimize confounding factors. Statistical methods included χ2 to analyze frequency of opioid prescription by hospital, parity, tobacco use, delivery method, and laceration type. An analysis of variance was used to analyze morphine equivalent dose by hospital. RESULTS: The percentage of women prescribed postpartum opioids varied significantly by hospital, ranging from 27.6% to 70.9% (P <0.001). Oxycodone-acetaminophen was the most commonly prescribed medication (50.3%) with each hospital having its preferred opioid type. Median number of tablets prescribed ranged from 20 to 40 (P < .0001). Primiparous women were more likely to receive opioids than multiparous women when broken down by a parity of 1, 2, 3, 4, and ≥5 (52.8%, 48.0%, 47.6%, 40.1%, and 45.8%, respectively, P = .0005). Among women who had vaginal deliveries, opioid prescription rates were higher in women who experienced either a second-degree laceration (35.5%, P = .0002) or a third-/fourth-degree laceration (59.3%, P < .001). CONCLUSION: Postpartum opioid prescription rates vary widely among hospitals, but providers within the same hospital tend to follow similar prescribing trends. The variation in prescribing found in our study illustrates the need for clear consensus guidelines for postpartum pain management.

Detection of opioids in umbilical cord lysates: an antibody-based rapid screening approach.

In pregnancy, opioids may be used medically and also misused. We hypothesized that the umbilical cord (UC) could be a good screening tool for determining opioid exposure and improving medical care. One hundred and one UC, each with 50 associated ICD9/ICD10 codes were used. Using predictive pharmacokinetic analysis we determined that opioids could be detected since last ingestion prior to birth. The UC were lysed and screened using ELISA detecting multiple opioids and their metabolites. Statistical comparisons to obstetric and neonatal outcomes were performed. Although the commercial ELISA was less sensitive in UC than blood or urine, there was perfect method selectivity as compared to a subset of cords designated positive or negative by clinical diagnostics, so our results are accurate and reliable. Absolute quantitation was not possible because the antibody cross reacts with multiple compounds, but 'low' or 'high' levels of exposure were assigned. Prevalence of opioids was 11%, which reduced to 7% when cesarean-section births were eliminated. For non-cesarean-section infants adjusted for preterm birth, advanced maternal age and smoking (independent risk factors), opioids were significantly associated with intra-uterine growth restriction (p = 0.017) and admission to neonatal intensive care (p = 0.002). UC can be collected noninvasively and rapidly providing a reliable tools for semi-quantitative opioid screening using ELISA. Moreover, as UC are usually discarded collection presents few technical or safety concerns for staff or patients. Further development of this methodology may provide a rapid, noninvasive clinical screening tool to identify NAS and/or opioid use in late pregnancy.

Investigating Mechanisms of Stillbirth in the Setting of Prenatal Substance Use.

INTRODUCTION: Intrauterine fetal demise affects between 0.4-0.8% of pregnancies worldwide. This significant adverse pregnancy outcome continues to be poorly understood. In utero exposure to substances increases the risk of stillbirth to varying degrees according to the type of substance and degree of exposure. The aim of this qualitative narrative review is to investigate common biologic relationships between stillbirth and maternal substance use. METHODS: A PubMed literature search was conducted to query the most commonly used substances and biologic mechanisms of stillbirth. Search terms included "stillbirth," "intrauterine fetal demise," "placenta," "cocaine," "tobacco," "alcohol," "methamphetamines," "opioids/ opiates," and "cannabis." RESULTS: There are very few studies identifying a direct link between substance use and stillbirth. Several studies demonstrate associations with placental lesions of insufficiency including poor invasion, vasoconstriction, and sequestration of toxic substances that inhibit nutrient transport. Restricted fetal growth is the most common finding in pregnancies complicated by all types of substance use. DISCUSSION: More research is needed to understand the biologic mechanisms of stillbirth. Such knowledge will be foundational to understanding how to prevent and treat the adverse effects of substances during pregnancy.

Screening, brief intervention, and referral to treatment for opioid and other substance use during infertility treatment.

Opioid use and misuse have reached epidemic proportions in the United States, especially in women of childbearing age, some of whom seek infertility treatments. Substance use is much more common than many of the conditions routinely screened for during the preconception period, and it can have devastating consequences for the woman and her family. Substance use can worsen infertility, complicate pregnancy, increase medical problems, and lead to psychosocial difficulties for the woman and her family. The reproductive endocrinologist thus has an ethical and medical duty to screen for substance use, provide initial counseling, and refer to specialized treatment as needed. This article provides an overview of screening, brief intervention, and referral to treatment (SBIRT), a public health approach shown to be effective in ameliorating the harms of substance use.

Sex-Specific Alterations of White Matter Developmental Trajectories in Infants With Prenatal Exposure to Methamphetamine and Tobacco.

IMPORTANCE: Methamphetamine is a common illicit drug used worldwide. Methamphetamine and/or tobacco use by pregnant women remains prevalent. However, little is known about the effect of comorbid methamphetamine and tobacco use on human fetal brain development. OBJECTIVE: To investigate whether microstructural brain abnormalities reported in children with prenatal methamphetamine and/or tobacco exposure are present at birth before childhood environmental influences. DESIGN, SETTING, AND PARTICIPANTS: A prospective, longitudinal study was conducted between September 17, 2008, and February 28, 2015, at an ambulatory academic medical center. A total of 752 infant-mother dyads were screened and 139 of 195 qualified neonates were evaluated (36 methamphetamine/tobacco exposed, 32 tobacco exposed, and 71 unexposed controls). They were recruited consecutively from the community. EXPOSURES: Prenatal methamphetamine and/or tobacco exposure. MAIN OUTCOMES AND MEASURES: Quantitative neurologic examination and diffusion tensor imaging performed 1 to 3 times through age 4 months; diffusivities and fractional anisotropy (FA) assessed in 7 white matter tracts and 4 subcortical brain regions using an automated atlas-based method. RESULTS: Of the 139 infants evaluated, 72 were female (51.8%); the mean (SE) postmenstrual age at baseline was 41.5 (0.27) weeks. Methamphetamine/tobacco-exposed infants showed delayed developmental trajectories on active muscle tone (group × age, P < .001) and total neurologic scores (group × age, P = .01) that normalized by ages 3 to 4 months. Only methamphetamine/tobacco-exposed boys had lower FA (group × age, P = .02) and higher diffusivities in superior (SCR) and posterior corona radiatae (PCR) (group × age × sex, P = .002; group × age × sex, P = .01) at baseline that normalized by age 3 months. Only methamphetamine/tobacco- and tobacco-exposed girls showed persistently lower FA in anterior corona radiata (ACR) (group, P = .04; group × age × sex, P = .01). Tobacco-exposed infants showed persistently lower axial diffusion in the thalamus and internal capsule across groups (P = .02). CONCLUSIONS AND RELEVANCE: Prenatal methamphetamine/tobacco exposure may lead to delays in motor development, with less coherent fibers and less myelination in SCR and PCR only in male infants, but these abnormalities may normalize by ages 3 to 4 months after cessation of stimulant exposure. In contrast, persistently less coherent ACR fibers were observed in methamphetamine/tobacco- and tobacco-exposed girls, possibly from increased dendritic branching or spine density due to epigenetic influences. Persistently lower diffusivity in the thalamus and internal capsule of all tobacco-exposed infants suggests aberrant axonal development. Collectively, prenatal methamphetamine and/or tobacco exposure may lead to delayed motor development and white matter maturation in sex- and regional-specific manners.

The role of screening, brief intervention, and referral to treatment in the perinatal period.

Substance use during pregnancy is at least as common as many of the medical conditions screened for and managed during pregnancy. While harmful and costly, it is often ignored or managed poorly. Screening, brief intervention, and referral to treatment is an evidence-based approach to manage substance use. In September 2012, the US Centers for Disease Control and Prevention convened an Expert Meeting on Perinatal Illicit Drug Abuse to help address key issues around drug use in pregnancy in the United States. This article reflects the formal conclusions of the expert panel that discussed the use of screening, brief intervention, and referral to treatment during pregnancy. Screening for substance use during pregnancy should be universal. It allows stratification of women into zones of risk given their pattern of use. Low-risk women should receive brief advice, those classified as moderate risk should receive a brief intervention, whereas those who are high risk need referral to specialty care. A brief intervention is a patient-centered form of counseling using the principles of motivational interviewing. Screening, brief intervention, and referral to treatment has the potential to reduce the burden of substance use in pregnancy and should be integrated into prenatal care.

ATP-binding cassette proteins BCRP, MRP1 and P-gp expression and localization in the human umbilical cord.

1. The umbilical cord is a direct conduit to the fetus hence transporters could have roles in partitioning substances between the maternal-placental-fetal units. Here we determined the expression and localization of the ATP-Binding Cassette (ABC) transporters BCRP (ABCG2), P-gp (ABCB1) and MRP1 (ABCC1) in human umbilical cords. 2. The mRNA for BCRP and MRP1 was detected in 25/25 samples, but P-gp was detected in only 5/25. ABC transporter mRNA expression relative to 18S was 25.6 ± 0.3, 26.5 ± 0.6 and 22.2 ± 0.2 cycles for BCRP, MRP1 and P-gp respectively. 3. Using a subset of 10 umbilical cords, BCRP protein was present in all samples (immunoblot) with positive correlation between mRNA and proteins (p = 0.07, r = 0.62) and between immunoblotting and immunohistochemistry (IHC) (p = 0.03, r = 0.67). P-gp protein was observed in 4/10 samples by both immunoblot and IHC, with no correlation between mRNA and protein (p = 0.45, r = 0.55) or immunoblotting and IHC (p = 0.2, r = 0.72), likely due to small sample size. MRP1 protein was not observed. 4. Localization of BCRP and P-gp proteins was to Wharton's jelly with no specific staining in arterial or venous endothelia. 5. Understanding ABC transporter expression in the umbilical cord may be useful for determining fetal exposures to xenobiotics if functional properties can be defined.

Biochemical Screening for in utero Drug Exposure.

Licit and illicit drug use is a common complication of pregnancy. Accurate information on drug use is difficult to obtain for many reasons as women fear self-disclosure or consenting for drug testing due to stigma, guilt, and fear of social and legal harm. As information about drug use is clinically very important, biochemical testing is an important adjunct to careful maternal history. In addition, research studies depend on accurate measures of exposure when reporting risks of a substance. This paper delineates available matrices for and methods of biochemical drug testing in pregnant women and neonates.

Methamphetamines and pregnancy outcomes.

INTRODUCTION: Methamphetamine (MA) is one of the most commonly used illicit drugs in pregnancy, yet studies on MA-exposed pregnancy outcomes have been limited because of retrospective measures of drug use; lack of control for confounding factors; other drug use, including tobacco; poverty; poor diet; and lack of prenatal care. This study presents prospective collected data on MA use and birth outcomes, controlling for most confounders. MATERIALS AND METHODS: This is a retrospective cohort study of women obtaining prenatal care from a clinic treating women with substance use disorders, on whom there are prospectively obtained data on MA and other drug use, including tobacco. Methamphetamine-exposed pregnancies were compared with non-MA exposed pregnancies and non-drug-exposed pregnancies, using univariate and multivariate analysis to control for confounders. RESULTS: One hundred forty-four infants were exposed to MA during pregnancy, 50 had first trimester exposure only, 45 had continuous use until the second trimester, 29 had continuous use until the third trimester, but were negative at delivery, and 20 had positive toxicology at delivery. There were 107 non-MA-exposed infants and 59 infants with no drug exposure. Mean birth weights were the same for MA-exposed and nonexposed infants (3159 g vs 3168 g; P = 0.9), although smaller than those without any drug exposure (3159 vs 3321; P = 0.04), infants with positive toxicology at birth (meconium or urine) were smaller than infants with first trimester exposure only (2932 g vs 3300 g; P = 0.01). Gestation was significantly shorter among the MA-exposed infants than that among nonexposed infants (38.5 vs 39.1 weeks; P = 0.045), and those with no drug exposure (38.5 vs 39.5; P = 0.0011), the infants with positive toxicology at birth had a clinically relevant shortening of gestation (37.3 weeks vs 39.1; P = 0.0002). CONCLUSIONS: Methamphetamine use during pregnancy is associated with shorter gestational ages and lower birth weight, especially if used continuously during pregnancy. Stopping MA use at any time during pregnancy improves birth outcomes, thus resources should be directed toward providing treatment and prenatal care.

Expression of Ror2 mediates invasive phenotypes in renal cell carcinoma.

Ror2 is a Wnt ligand receptor that is overexpressed in a variety of tumors including clear cell renal cell carcinoma (ccRCC). Here we demonstrate that expression of wild type Ror2 results in increased tumorigenic properties in in vitro cell culture and in vivo xenograft models. In addition, Ror2 expression produced positive changes in both cell migration and invasion, which were dependent on matrix metalloprotease 2 (MMP2) activity. Mutations in key regions of the kinase domain of Ror2 resulted in the abrogation of increased tumor growth, cell migration, and cell invasion observed with expression of wild-type Ror2. Finally, we examined Ror2 expression as a prognostic biomarker for ccRCC utilizing the TCGA ccRCC dataset. High expression of Ror2 showed a significant correlation with higher clinical stage, nuclear grade, and tumor stage. Furthermore, high expression of Ror2 in ccRCC patients correlated with significant lower overall survival, cancer specific survival, and recurrence free survival. Together, these findings suggest that Ror2 plays a central role in influencing the ccRCC phenotype, and can be considered as a negative prognostic biomarker and potential therapeutic target in this cancer.

Delineation of a FOXA1/ERα/AGR2 regulatory loop that is dysregulated in endocrine therapy-resistant breast cancer.

UNLABELLED: Tamoxifen, a selective estrogen receptor (ER) modulator (SERM), remains a frontline clinical therapy for patients with ERα-positive breast cancer. However, the relatively rapid development of resistance to this drug in the metastatic setting remains an impediment to a durable response. Although drug resistance likely arises by many different mechanisms, the consensus is that most of the implicated pathways facilitate the outgrowth of a subpopulation of cancer cells that can either recognize tamoxifen as an agonist or bypass the regulatory control of ERα. Notable in this regard is the observation here and in other studies that expression of anterior gradient homology 2 (AGR2), a known proto-oncogene and disulfide isomerase, was induced by both estrogen (17ß-estradiol, E2) and 4-hydroxytamoxifen (4OHT) in breast cancer cells. The importance of AGR2 expression is highlighted here by the observation that (i) its knockdown inhibited the growth of both tamoxifen-sensitive and -resistant breast cancer cells and (ii) its increased expression enhanced the growth of ERα-positive tumors in vivo and increased the migratory capacity of breast cancer cells in vitro. Interestingly, as with most ERα target genes, the expression of AGR2 in all breast cancer cells examined requires the transcription factor FOXA1. However, in tamoxifen-resistant cells, the expression of AGR2 occurs in a constitutive manner, requiring FOXA1, but loses its dependence on ER. Taken together, these data define the importance of AGR2 in breast cancer cell growth and highlight a mechanism where changes in FOXA1 activity obviate the need for ER in the regulation of this gene. IMPLICATIONS: These findings reveal the transcriptional interplay between FOXA1 and ERα in controlling AGR2 during the transition from therapy-sensitive to -resistant breast cancer and implicate AGR2 as a relevant therapeutic target.

Receptor tyrosine kinase-like orphan receptor 2 (Ror2) expression creates a poised state of Wnt signaling in renal cancer.

Expression of the receptor tyrosine kinase-like orphan receptor 2 (Ror2) has been identified in an increasing array of tumor types and is known to play a role as an important mediator of Wnt signaling cascades. In this study, we aimed to clarify Ror2 interactions with the Wnt pathways within the context of renal cell carcinoma (RCC). An examination of Ror2 expression in primary human RCC tumors showed a significant correlation with several Wnt signaling genes, including the classical feedback target gene Axin2. We provide evidence that Ror2 expression results in a partially activated state for canonical Wnt signaling through an increased signaling pool of ß-catenin, leading to an enhancement of downstream target genes following Wnt3a stimulation in both renal and renal carcinoma-derived cells. Additionally, inhibition of low-density lipoprotein receptor-related protein 6 (LRP6) with either siRNA or dickkopf decreased the response to Wnt3a stimulation, but no change was seen in the increased ß-catenin pool associated with Ror2 expression, suggesting that LRP6 cofactor recruitment is necessary for a Wnt3a-induced signal but that it does not participate in the Ror2 effect on ß-catenin signaling. These results highlight a new role for Ror2 in conveying a tonic signal to stabilize soluble ß-catenin and create a poised state of enhanced responsiveness to Wnt3a exogenous signals in RCC.

Implementation and evaluation of a harm-reduction model for clinical care of substance using pregnant women.

BACKGROUND: Methamphetamine (MA) use during pregnancy is associated with many pregnancy complications, including preterm birth, small for gestational age, preeclampsia, and abruption. Hawaii has lead the nation in MA use for many years, yet prior to 2007, did not have a comprehensive plan to care for pregnant substance-using women. In 2006, the Hawaii State Legislature funded a pilot perinatal addiction clinic. The Perinatal Addiction Treatment Clinic of Hawaii was built on a harm-reduction model, encompassing perinatal care, transportation, child-care, social services, family planning, motivational incentives, and addiction medicine. We present the implementation model and results from our first one hundred three infants (103) seen over 3 years of operation of the program. METHODS: Referrals came from community health centers, hospitals, addiction treatment facilities, private physician offices, homeless outreach services and self-referral through word-of-mouth and bus ads. Data to describe sample characteristics and outcome was obtained prospectively and retrospectively from chart abstraction and delivery data. Drug use data was obtained from the women's self-report and random urine toxicology during the pregnancy, as well as urine toxicology at the time of birth on mothers, and urine and meconium toxicology on the infants. Post-partum depression was measured in mothers with the Edinburgh Post-Partum depression scale. Data from Path clinic patients were compared with a representative cohort of women delivering at Kapiolani Medical Center for Women and Children during the same time frame, who were enrolled in another study of pregnancy outcomes. Ethical approval for this study was obtained through the University of Hawaii Committee for Human Studies. RESULTS: Between April 2007 and August 2010, 213 women with a past or present history of addiction were seen, 132 were pregnant and 97 delivered during that time. 103 live-born infants were delivered. There were 3 first-trimester Spontaneous Abortions, two 28-week intrauterine fetal deaths, and two sets of twins and 4 repeat pregnancies. Over 50% of the women had lost custody of previous children due to substance use. The majority of women who delivered used methamphetamine (86%), either in the year before pregnancy or during pregnancy. Other drugs include marijuana (59.8%), cocaine (33%), opiates (9.6%), and alcohol (15.2%). Of the women served, 85% smoked cigarettes upon enrollment. Of the 97 women delivered during this period, all but 4 (96%) had negative urine toxicology at the time of delivery. Of the 103 infants, 13 (12.6%) were born preterm, equal to the state and national average, despite having many risk factors for prematurity, including poverty, poor diet, smoking and polysubstance use. Overwhelmingly, the women are parenting their children, > 90% retained custody at 8 weeks. Long-term follow-up showed that women who maintained custody chose long-acting contraceptive methods; while those who lost custody had a very high (> 50%) repeat pregnancy rate at 9 months post delivery. CONCLUSION: Methamphetamine use during pregnancy doesn't exist is isolation. It is often combined with a multitude of other adverse circumstances, including poverty, interpersonal violence, psychiatric comorbidity, polysubstance use, nutritional deficiencies, inadequate health care and stressful life experiences. A comprehensive harm reduction model of perinatal care, which aims to ameliorate some of these difficulties for substance-using women without mandating abstinence, provides exceptional birth outcomes and can be implemented with limited resources.

Disparate rates of persistent smoking and drug use during pregnancy of women of Hawaiian ancestry.

BACKGROUND: Significant disparity in smoking rates has been previously reported in pregnant and non-pregnant women of Native Hawaiian ancestry. Disparities in drug use rates have also been reported in non-pregnant women of Native Hawaiian ancestry. OBJECTIVE: We undertook this study to compare rates of smoking and drug use during pregnancy among women in Hawaii to see if these differences are associated with disparities in pregnancy complications among Native Hawaiian women. METHODS: Women were enrolled in the Pacific Research Center on Early Human Development study from July 2007 to January 2008, according to approved protocols. Persistent smoking was defined as self-reported smoking within 1 week of admission for labor. Drug use data was assessed by self-report, or if available, toxicology tests at the time of labor. RESULTS: There were 868 women enrolled in the study during this period. Women of Hawaiian/part-Hawaiian ancestry comprised 22% of the study population. Rates of persistent smoking and drug use among Hawaiian women were significantly higher than the remainder of the study population (21% and 8.3% vs. 7.8% and 2.1%, respectively, P < .001 for both). Methamphetamine use was associated with an almost 5-fold increase in preterm birth and smoking a 3.4% decrease in birth weights. DISCUSSION AND CONCLUSION: Women of Hawaiian ancestry continue to smoke and use illicit drugs during pregnancy at significantly higher rates than women of other ethnic groups in Hawaii. In addition to the immediate effects on pregnancy, long-term adverse outcomes of in utero exposures of the offspring remain an important health disparity.

Identification of Ror2 as a hypoxia-inducible factor target in von Hippel-Lindau-associated renal cell carcinoma.

Ror2 is an orphan receptor tyrosine kinase with expression normally restricted to early stages of development. However, emerging evidence has placed aberrantly expressed Ror2, leading to an invasive phenotype, in several cancers including renal cell carcinoma (RCC). Although Ror2 is currently identified as up-regulated in an assortment of cancers, neither the regulatory role or mechanism of action have been delineated. We sought to place Ror2 in the most commonly mutated pathway of RCC, the loss of the tumor suppressor von Hippel-Lindau (VHL), which causes hypoxia-inducible factor (HIF)-1alpha and -2alpha stabilization and the transcriptional activation of a broad repertoire of response genes. We found that Ror2 was indeed associated with the pVHL loss in RCC as well as with VHL somatic mutations tightly coordinated with the induction of RCC. Additionally, knockdown and rescue analysis of HIF expression suggests that Ror2 is dependent on pathologic stabilization of either HIF-1alpha or HIF-2alpha. Subsequent evaluation of the ROR2 promoter suggests that HIF-2alpha and its dimerization partner, aryl hydrocarbon nuclear transferase localize to the ROR2 promoter via a cryptic transcriptional element. This data substantiates a unique regulation pattern for Ror2 in the VHL-HIF axis that has the potential to be applied to other cancer etiologies.

Extensive post-transcriptional regulation of microRNAs and its implications for cancer.

MicroRNAs (miRNAs) are short, noncoding RNAs that post-transcriptionally regulate gene expression. While hundreds of mammalian miRNA genes have been identified, little is known about the pathways that regulate the production of active miRNA species. Here we show that a large fraction of miRNA genes are regulated post-transcriptionally. During early mouse development, many miRNA primary transcripts, including the Let-7 family, are present at high levels but are not processed by the enzyme Drosha. An analysis of gene expression in primary tumors indicates that the widespread down-regulation of miRNAs observed in cancer is due to a failure at the Drosha processing step. These data uncover a novel regulatory step in miRNA function and provide a mechanism for miRNA down-regulation in cancer.

Molecularly targeted therapy in renal cell carcinoma.

Recent developments in the molecular biology of renal cell carcinoma have identified multiple pathways associated with the development of this cancer. Multiple strategies have been investigated targeting these pathways, with significant clinical benefits shown in early studies. This review aims to overview the findings of recent clinical trials and clarify the development of these compounds for use in renal cell carcinoma. The authors also aim to clarify the molecular pathways implicated in renal cell carcinoma and the clinical results in metastatic renal cell carcinoma with agents targeting these pathways. The relevant literature was reviewed concerning pathways implicated in the pathophysiology of renal cell carcinoma including pathways activated secondary to von Hippel-Lindau gene inactivation and PI-3 kinase/Akt/mammalian target of rapamycin pathway activation. Therapeutic targeting based upon underlying molecular biology in renal cell carcinoma has strong rationale. Substantial clinical activity has been reported with various agents targeting these pathways, most notably with vascular endothelial growth factor-targeted therapy. However, investigation is needed to optimally utilize these agents at the appropriate stage of disease and in the best combinations for maximal clinical benefit.