The PIAS-like Coactivator Zmiz1 Is a Direct and Selective Cofactor of Notch1 in T Cell Development and Leukemia.

Pan-NOTCH inhibitors are poorly tolerated in clinical trials because NOTCH signals are crucial for intestinal homeostasis. These inhibitors might also promote cancer because NOTCH can act as a tumor suppressor. We previously reported that the PIAS-like coactivator ZMIZ1 is frequently co-expressed with activated NOTCH1 in T cell acute lymphoblastic leukemia (T-ALL). Here, we show that similar to Notch1, Zmiz1 was important for T cell development and controlled the expression of certain Notch target genes, such as Myc. However, unlike Notch, Zmiz1 had no major role in intestinal homeostasis or myeloid suppression. Deletion of Zmiz1 impaired the initiation and maintenance of Notch-induced T-ALL. Zmiz1 directly interacted with Notch1 via a tetratricopeptide repeat domain at a special class of Notch-regulatory sites. In contrast to the Notch cofactor Maml, which is nonselective, Zmiz1 was selective. Thus, targeting the NOTCH1-ZMIZ1 interaction might combat leukemic growth while avoiding the intolerable toxicities of NOTCH inhibitors.

Stage-specific roles for Zmiz1 in Notch-dependent steps of early T-cell development.

Notch1 signaling must elevate to high levels in order to drive the proliferation of CD4-CD8- double-negative (DN) thymocytes and progression to the CD4+CD8+ double-positive (DP) stage through ß-selection. During this critical phase of pre-T-cell development, which is also known as the DN-DP transition, it is unclear whether the Notch1 transcriptional complex strengthens its signal output as a discrete unit or through cofactors. We previously showed that the protein inhibitor of activated STAT-like coactivator Zmiz1 is a context-dependent cofactor of Notch1 in T-cell leukemia. We also showed that withdrawal of Zmiz1 generated an early T-lineage progenitor (ETP) defect. Here, we show that this early defect seems inconsistent with loss-of-Notch1 function. In contrast, at the later pre-T-cell stage, withdrawal of Zmiz1 impaired the DN-DP transition by inhibiting proliferation, like withdrawal of Notch. In pre-T cells, but not ETPs, Zmiz1 cooperatively regulated Notch1 target genes Hes1, Lef1, and Myc. Enforced expression of either activated Notch1 or Myc partially rescued the Zmiz1-deficient DN-DP defect. We identified residues in the tetratricopeptide repeat (TPR) domain of Zmiz1 that bind Notch1. Mutating only a single residue impaired the Zmiz1-Notch1 interaction, Myc induction, the DN-DP transition, and leukemic proliferation. Similar effects were seen using a dominant-negative TPR protein. Our studies identify stage-specific roles of Zmiz1. Zmiz1 is a context-specific cofactor for Notch1 during Notch/Myc-dependent thymocyte proliferation, whether normal or malignant. Finally, we highlight a vulnerability in leukemic cells that originated from a developmentally important Zmiz1-Notch1 interaction that is hijacked during transformation from normal pre-T cells.

Pharmacogenomic knowledge and awareness among diverse patients treated with angiotensin converting enzyme inhibitors.

We developed novel electronic phenotyping algorithms for the BioMe biobank data, which accurately identified angiotensin converting enzyme inhibitor (ACEi)-induced angioedema cases and controls. A survey was mailed to all 1075 patients and 91 were returned. Over a third reported that prescribing physicians had not discussed with them the concepts of interindividual drug response variability or adverse event risk, and 73% of patients were previously unaware of pharmacogenomics; however, most patients were interested in having pharmacogenomic testing. Moreover, 67% of patients indicated that pharmacogenomic testing would positively influence their medication compliance. In addition to identifying an innovative approach to define biobank cohorts for pharmacogenomic studies, these results indicate that patients are interested in pharmacogenomic testing, which could translate to improved adherence.

Targeting DNA repair and the cell cycle in glioblastoma.

Glioblastoma is a disease with poor outcomes despite standard therapy. Specific targeting of the DNA damage response is a strategy that is becoming increasingly employed in oncology and has intriguing potential for improving outcomes in glioblastoma. DNA damage targeting has implications for improving current therapy as well as the potential to leverage inherent differences in glioblastoma cells to widen the therapeutic window.

Ocular phenotype in a patient with PAX2 gene mutation-associated papillorenal syndrome.

BACKGROUND: Papillorenal syndrome is an autosomal dominant disorder associated with mutations in the gene PAX2 and often presents with characteristic and specific optic disc findings, frequently with renal dysplasia. In at least half of cases, an identifiable mutation in the PAX2 gene can be detected. We report the ocular findings in a second case of papillorenal syndrome with the c.350 G > C (p.Arg117Pro) mutation detected within the PAX2 gene. METHODS: A case report of papillorenal syndrome due to PAX2 mutation. Complete ophthalmologic examination was performed as well as color fundus photography, fundus autofluorescence, and optical coherence tomography (OCT). Genetic testing was performed using a next-generation sequencing with CNV calling (NGS-CNV) panel test containing 55 genes associated with nephrotic syndrome or focal segmental glomerulosclerosis. RESULTS: An 11-year-old boy who presented with hypertension and proteinuria was found to have stage IV chronic kidney disease. Presenting visual acuity was 20/25 in the right eye and 20/20 in the left eye. The fundus exam showed bilateral centrally excavated optic discs with absent central retinal vessels and a compensatory multiplicity of cilioretinal vessels, characteristic and specific for papillorenal syndrome. OCT showed outer retinal atrophy and macular schisis. Genetic testing identified the likely pathogenic c.350 G > C (p.Arg117Pro) mutation in PAX2. CONCLUSIONS: We report the first description, to our knowledge, of the clinical presentation, ocular and systemic findings, and ophthalmic imaging in an individual with papillorenal syndrome associated with the PAX2 c.350 G > C (p.Arg117Pro) mutation. Our case adds to the current understanding of papillorenal syndrome and demonstrates that this condition is associated with a pathognomonic optic disc appearance and significant renal disease.

Steroid and anticonvulsant prophylaxis for stereotactic radiosurgery: Large variation in physician recommendations.

PURPOSE/OBJECTIVE(S): The risk of developing symptomatic edema or seizure following stereotactic radiosurgery (SRS) is poorly defined, and many practitioners prescribe prophylactic corticosteroids and/or anticonvulsants. Because there are no clear guidelines regarding appropriate use, we sought to characterize prescribing practices and factors associated with these recommendations. METHODS AND MATERIALS: We conducted a 1-time, internet-based survey among 500 randomly selected radiation oncologists self-described as specializing in central nervous system diseases who were registered in the American Society for Radiation Oncology directory. Physicians were contacted by e-mail and invited to complete the 22-question survey. RESULTS: The response rate was 32% (n = 161). Sixty-six percent of respondents had been in practice for >10 years, and 45% of respondents practiced at an academic medical center. During/after SRS, 53% of respondents "always" or "usually" recommended corticosteroids, whereas 47% "never," "rarely," or "sometimes" recommended them. When prescribing corticosteroids, the recommended duration of use was <1 week, 1-2 weeks, or >2 weeks among 49%, 33%, and 18% of respondents, respectively. Respondents who worked in an academic medical center were less likely to prescribe corticosteroids, although this did not reach significance (P = .09). Seizure prophylaxis was less common overall, as 79% of respondents "rarely" or "never" prescribed anticonvulsants for SRS. Respondents who prescribed anticonvulsants more frequently had higher estimations of the risk of seizure within 2 weeks of SRS (P < .001), and their recommended duration of anticonvulsant use was <1 week, 1-2 weeks, and >2 weeks among 35%, 25%, and 41% of respondents, respectively. CONCLUSIONS: There is extreme variation in physician recommendations regarding prophylactic corticosteroid and anticonvulsant use for patients undergoing SRS. Further investigation of the risks and benefits of these medications for SRS is warranted, which may promote guideline development and more patient-centered, rational prescribing practices.

Aggressive therapy for patients with non-small cell lung carcinoma and synchronous brain-only oligometastatic disease is associated with long-term survival.

OBJECTIVES: Optimal therapy for patients with non-small cell lung carcinoma (NSCLC) presenting with synchronous brain-only oligometastases (SBO) is not well defined. We sought to analyze the effect of differing therapeutic paradigms in this subpopulation. MATERIALS AND METHODS: We retrospectively analyzed NSCLC patients with 1-4 SBO diagnosed between 1/2000 and 1/2011 at our institution. Patients with T0 tumors or documented Karnofsky Performance Status <70 were excluded. Aggressive thoracic therapy (ATT) was defined as resection of the primary disease or chemoradiotherapy whose total radiation dose exceeded 45 Gy. Cox proportional hazards and competing risks models were used to analyze factors affecting survival and first recurrence in the brain. RESULTS: Sixty-six patients were included. Median follow-up was 31.9 months. Intrathoracic disease extent included 9 stage I, 10 stage II and 47 stage III patients. Thirty-eight patients received ATT, 28 did not. Patients receiving ATT were younger (median age 55 vs. 60.5 years, p=0.027) but were otherwise similar to those who did not. Receipt of ATT was associated with prolonged median overall survival (OS) (26.4 vs. 10.5 months; p<0.001) with actuarial 2-year rates of 54% vs. 26%. ATT remained associated with OS after controlling for age, thoracic stage, performance status and initial brain therapy (HR 0.40, p=0.009). On multivariate analysis, the risk of first failure in the brain was associated with receipt of ATT (HR 3.62, p=0.032) and initial combined modality brain therapy (HR 0.34, p=0.046). CONCLUSION: Aggressive management of thoracic disease in NSCLC patients with SBO is associated with improved survival. Careful management of brain disease remains important, especially for those treated aggressively.

The role of whole brain radiation therapy in the management of melanoma brain metastases.

BACKGROUND: Brain metastases are common in patients with melanoma, and optimal management is not well defined. As melanoma has traditionally been thought of as "radioresistant," the role of whole brain radiation therapy (WBRT) in particular is unclear. We conducted this retrospective study to identify prognostic factors for patients treated with stereotactic radiosurgery (SRS) for melanoma brain metastases and to investigate the role of additional up-front treatment with whole brain radiation therapy (WBRT). METHODS: We reviewed records of 147 patients who received SRS as part of initial management of their melanoma brain metastases from January 2000 through June 2010. Overall survival (OS) and time to distant intracranial progression were calculated using the Kaplan-Meier method. Prognostic factors were evaluated using the Cox proportional hazards model. RESULTS: WBRT was employed with SRS in 27% of patients and as salvage in an additional 22%. Age at SRS > 60 years (hazard ratio [HR] 0.64, p = 0.05), multiple brain metastases (HR 1.90, p = 0.008), and omission of up-front WBRT (HR 2.24, p = 0.005) were associated with distant intracranial progression on multivariate analysis. Extensive extracranial metastases (HR 1.86, p = 0.0006), Karnofsky Performance Status (KPS) ≤ 80% (HR 1.58, p = 0.01), and multiple brain metastases (HR 1.40, p = 0.06) were associated with worse OS on univariate analysis. Extensive extracranial metastases (HR 1.78, p = 0.001) and KPS (HR 1.52, p = 0.02) remained significantly associated with OS on multivariate analysis. In patients with absent or stable extracranial disease, multiple brain metastases were associated with worse OS (multivariate HR 5.89, p = 0.004), and there was a trend toward an association with worse OS when up-front WBRT was omitted (multivariate HR 2.56, p = 0.08). CONCLUSIONS: Multiple brain metastases and omission of up-front WBRT (particularly in combination) are associated with distant intracranial progression. Improvement in intracranial disease control may be especially important in the subset of patients with absent or stable extracranial disease, where the competing risk of death from extracranial disease is low. These results are hypothesis generating and require confirmation from ongoing randomized trials.

Kisspeptin administration to women: a window into endogenous kisspeptin secretion and GnRH responsiveness across the menstrual cycle.

CONTEXT: Kisspeptin is the most powerful known stimulus of GnRH-induced LH secretion across mammalian species. However, the effects of kisspeptin are just being explored, and the dynamics of kisspeptin responsiveness across the menstrual cycle are incompletely understood. OBJECTIVE: The objective of the study was to characterize the effects of kisspeptin on GnRH secretion in healthy women in different phases of the menstrual cycle. PARTICIPANTS AND INTERVENTION: Ten women in the early follicular phase, three women in the late follicular (preovulatory) phase, and 14 women in the midluteal phase received a bolus of kisspeptin 112-121 0.24 nmol/kg iv. An additional four women in the early to midfollicular phase received kisspeptin 112-121 0.72 nmol/kg iv. RESULTS: The response to kisspeptin varied depending on the phase of the menstrual cycle. LH pulses were observed immediately after kisspeptin administration in all luteal and preovulatory women. However, only half the women in the early follicular phase had unambiguous kisspeptin responses. Increasing the kisspeptin dose did not increase the LH response in early to midfollicular phase women. Kisspeptin did not appear to reset the GnRH pulse generator in women as it does in men. CONCLUSIONS: Differences in responses to exogenous kisspeptin across the menstrual cycle suggest that kisspeptin tone is higher in the early follicular phase compared with other cycle phases. The mechanisms that determine the timing of GnRH pulse generation in men and women appear to be distinct.

Importance of extracranial disease status and tumor subtype for patients undergoing radiosurgery for breast cancer brain metastases.

PURPOSE: In this retrospective study, we report on outcomes and prognostic factors for patients treated with stereotactic radiosurgery (SRS) for breast cancer brain metastases. METHODS AND MATERIALS: We identified 132 consecutive patients with breast cancer who were treated with SRS for brain metastases from January 2000 through June 2010. We retrospectively reviewed records of the 51 patients with adequate follow-up data who received SRS as part of the initial management of their brain metastases. Overall survival (OS) and time to central nervous system (CNS) progression from the date of SRS were calculated using the Kaplan-Meier method. Prognostic factors were evaluated using the Cox proportional hazards model. RESULTS: Triple negative subtype was associated with CNS progression on univariate analysis (hazard ratio [HR] = 5.0, p = 0.008). On multivariate analysis, triple negative subtype (HR = 8.6, p = 0.001), Luminal B subtype (HR = 4.3, p = 0.03), and omission of whole-brain radiation therapy (HR = 3.7, p = 0.02) were associated with CNS progression. With respect to OS, Karnofsky Performance Status (KPS) ≤ 80% (HR = 2.0, p = 0.04) and progressive extracranial disease (HR = 3.1, p = 0.002) were significant on univariate analysis; KPS ≤ 80% (HR = 4.1, p = 0.0004), progressive extracranial disease (HR = 6.4, p < 0.0001), and triple negative subtype (HR = 2.9, p = 0.04) were significant on multivariate analysis. Although median survival times were consistent with those predicted by the breast cancer-specific Graded Prognostic Assessment (Breast-GPA) score, the addition of extracranial disease status further separated patient outcomes. CONCLUSIONS: Tumor subtype is associated with risk of CNS progression after SRS for breast cancer brain metastases. In addition to tumor subtype and KPS, which are incorporated into the Breast-GPA, progressive extracranial disease may be an important prognostic factor for OS.

Kisspeptin resets the hypothalamic GnRH clock in men.

CONTEXT: Reproduction in all mammals is controlled by a hypothalamic clock that produces periodic secretory pulses of GnRH, but how the timing of these pulses is determined is poorly understood. The neuropeptide kisspeptin potently and selectively stimulates the secretion of GnRH. Although this property of kisspeptin is well described, the effects of kisspeptin on endogenous GnRH pulse generation remain largely unexplored. OBJECTIVE: The objective of the study was to detail the effects of kisspeptin on GnRH secretion, as reflected by LH secretion, in men. PARTICIPANTS: Thirteen healthy adult men participated in the study. INTERVENTION: The intervention was the administration of a single iv bolus of the C-terminal decapeptide of kisspeptin (amino acids 112-121 of the parent protein). RESULTS: Kisspeptin induced an immediate LH pulse, regardless of the timing of the previous endogenous pulse. The kisspeptin-induced pulses were on average larger than endogenous pulses (amplitude 5.0 ± 1.0 vs. 2.1 ± 0.3 mIU/ml, P = 0.02). Comparison of the morphology of kisspeptin-induced LH pulses in healthy men with that of GnRH-induced LH pulses in men with isolated GnRH deficiency suggests that a single i.v. bolus of kisspeptin triggered sustained GnRH release lasting approximately 17 min. Furthermore, kisspeptin reset the GnRH pulse generator, as it not only induced an immediate LH pulse but also delayed the next endogenous pulse by an interval approximating the normal interpulse interval. CONCLUSIONS: As the first known agent capable of resetting the hypothalamic GnRH pulse generator, kisspeptin can be used as a physiological tool for studying GnRH pulse generation and opens a door to understanding the mechanisms of biological clocks in general.