Citations

Abstract Background: Our group and others have identified a subset of ER/PR(−) breast cancers characterized by expression of the androgen receptor (AR) and androgen-dependent growth (Doane 2006). We conducted a proof-of-concept multicenter phase II study to test the efficacy of the AR-antagonist, bicalutamide for the treatment of AR(+) ER/PR(−) MBC (NCT00468715). Results of the primary endpoint, clinical benefit rate (CBR), were presented at ASCO (Gucalp 2012). Data for the impact of bicalutamide on circulating hormone levels in women are limited. Elevations in serum testosterone (T) and estradiol (E) have been observed for men treated with bicalutamide. We hypothesized comparable patterns of change in circulating endocrine markers in response to bicalutamide for women with MBC. Methods: Patients (pts) with AR(+) (IHC ≥10%), ER/PR(−) (IHC <10%) MBC were eligible for treatment (tx) if ECOG performance status ≤2 and normal organ function regardless of menopausal status. There was no limit to prior tx except prior trastuzumab required if HER2(+). Tx consisted of bicalutamide 150mg orally daily in 28-day cycles (C). Toxicity assessed q4 weeks, response q12wks. Primary endpoint was CBR. Peripheral blood was collected for total and free T, E and sex hormone binding globulin (SHBG) at baseline, start of C2 (C2) and at end of study (EOS). Standard institutional assays were used. A Wilcoxon signed-rank test was done to compare baseline to C2 and EOS values. Results: 26 patients with AR(+) ER/PR(−) MBC were treated on study. Evaluable number (n) of pts at baseline, C2 and EOS are 26, 26 and 19 respectively. Two pts remain on study. Menopausal status: pre=2, post=24. Baseline median total and free T and estradiol were consistent with expected norms, however a wide range was observed (Table). There were no significant differences observed for median free T, total T, E or SHBG between baseline and C2 or baseline and EOS. Changes in hormone levels could not be stratified by menopausal status or response to bicalutamide given small sample size. Given the wide range of baseline values, we examined the percent change for each endocrine biomarker from baseline to C2 and EOS. As shown in the Table, there was no difference in median percent change observed across time points for each biomarker. Conclusions: No discernible patterns of change in T, E or SHBG were observed in response to bicalutamide therapy when given to women for the treatment of AR(+), ER/PR(−) MBC. These circulating hormones require further evaluation for use as a pharmacodynamic marker. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-05-02.

Abstract Background: Mucinous ovarian carcinomas (MC) and mucinous borderline ovarian tumours (MBOT) are associated with ERBB2 amplification and KRAS activating mutations. These events occur in a near-mutually exclusive pattern, and KRAS mutations are more prevalent in MBOTs than MC's whereas ERBB2 amplification is more frequently seen in MCs. Frequencies of mutations in other oncogenes and tumour suppressor genes in MC are not well established though TP53, BRAF, NRAS, and CDKN2A mutations have all been reported. As these carcinomas are commonly chemo-resistant a definitive molecular categorization of this subtype is needed as treatment options are explored. Methods: We undertook review of pathology reports and after exclusion of potential gastric, appendiceal or pancreatic involvement over 100 mucinous ovarian tumours were identified. HPV testing was undertaken to exclude rare metastasis from endocervical primary site. All specimens were assayed for p53 expression via TMA and subject to sequencing of common cancer gene hotspots using Ion-Torrent or Illumina MiSeq. Previously derived data on ERBB2 status was combined in our analysis and, where available, samples showing heterogeneity of ERBB2 amplification and any other Ras-pathway activating mutation were microdissected with components evaluated independently for concurrent hotspot mutations. Results: All samples were consistent with mucinous tumours of ovarian origin and none were HPV positive. We detected mutations in KRAS, BRAF, CDKN2A, TP53, PTEN, PIK3CA as well as presumed somatic/detrimental, variants in APC that have not previously been reported in mucinous tumours. Despite some samples having enriched tumour content, lower than expected allelic frequencies of KRAS activating mutations suggested intra-tumoural heterogeneity. This was consistent with results observed previously with rare ERBB2 amplification coinciding KRAS mutations. Conclusions: The prevalence of Ras-pathway mutations, especially amongst borderline lesions, suggests these mutations are critical for tumour onset. However varying allelic frequencies of KRAS mutations suggest progression to carcinoma is strongly influenced by other molecular features. Citation Format: Michael S. Anglesio, Robertson Mackenzie, Stefan Kommoss, Boris J. Winterhoff, Benjamin Kipp, Jaoquin Garcia, Jesse S. Voss, Kevin Halling, Sarah Kerr, Janine Senz, Winnie Yang, Magnus von Knebel Doeberitz, Elena-Sophie Prigge, Miriam Reuschenbach, Anna V. Tinker, Blake Gilks, Jamie N. Bakkum-Gamez, David G. Huntsman, Jessica N. McAlpine. Defining ovarian mucinous tumors: Cancer genes and heterogeneity. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr A18.

AbstractBackgroundHeme oxygenase 1 (HO‐1) degrades heme and protects against oxidative stress. In vitro and animal models suggest that HO‐1 is beneficial in several diseases (e.g., postoperative ileus, gastroparesis, acute pancreatitis, and colitis). However, the only drugs (i.e., hemin and heme arginate) which pharmacologically upregulate HO‐1 in humans are expensive and can only be administered intravenously. Our aims were to compare the effects of placebo, aspirin, and simvastatin alone, and with α‐lipoic acid, on HO‐1 protein concentration and activity in humans.MethodsThis randomized, double‐blind, placebo‐controlled study compared the effects of three oral regimens administered for 7 days, i.e., placebo; aspirin (325 mg twice daily) and simvastatin (40 mg twice daily); aspirin, simvastatin, and the sodium salt of R‐ α‐lipoic acid (NaRLA, 600 mg three times daily) on markers of HO‐1 activation (i.e., plasma HO‐1 protein concentration and venous monocyte HO‐1 protein activity) in 18 healthy subjects (14 females). Markers of HO‐1 activation were evaluated at baseline, days 2, and 7.Key ResultsBaseline HO‐1 protein concentrations and activity were similar among the three groups. Compared to placebo, aspirin and simvastatin combined, or together with NaRLA did not affect HO‐1 protein concentration or activity at 2 or 7 days. HO‐1 protein concentrations and activity were correlated on day 7 (r = 0.75, p = 0.0004) but not at baseline and on day 2.Conclusions & InferencesAt therapeutic doses, aspirin, simvastatin, and α‐lipoic acid do not increase plasma HO‐1 protein concentration or venous monocyte HO‐1 activity in healthy humans.

Key PointsWe identified CRBN-binding proteins and confirmed recent work implicating the Ikaros transcription factors as important members. Low IZKF1 levels predict lack of IMiD responsiveness and shorter OS; IZKF1 expression is a potential predictive biomarker for clinic application.

Abstract Despite some advances, pancreatic ductal adenocarcinoma (PDAC) remains generally refractory to current treatments. Desmoplastic stroma, a consistent hallmark of PDAC, has emerged as a major source of therapeutic resistance and thus potentially promising targets for improved treatment. The glycan-binding protein galectin-1 (Gal1) is highly expressed in PDAC stroma, but its roles there have not been studied. Here we report functions and molecular pathways of Gal1 that mediate its oncogenic properties in this setting. Genetic ablation of Gal1 in a mouse model of PDAC (EIa-myc mice) dampened tumor progression by inhibiting proliferation, angiogenesis, desmoplasic reaction and by stimulating a tumor-associated immune response, yielding a 20% increase in relative lifesplan. Cellular analyses in vitro and in vivo suggested these effects were mediated through the tumor microenvironment. Importantly, acinar-to-ductal metaplasia, a crucial step for initiation of PDAC, was found to be regulated by Gal1. Mechanistic investigations revealed that Gal1 promoted Hedgehog pathway signaling in PDAC cells and stromal fibroblasts as well as in Ela-myc tumors. Taken together, our findings establish a function for Gal1 in tumor-stroma crosstalk in PDAC and provide a preclinical rationale for Gal1 targeting as a microenvironment-based therapeutic strategy. Cancer Res; 74(13); 3512–24. ©2014 AACR.

Objective: To describe 3 cases of clozapine toxicity associated with infectious and/or inflammatory processes. Case Summaries: Three patients stable on clozapine therapy prior to a medical hospital admission developed clozapine toxicity. It was suspected that an acute infectious and/or inflammatory process in each patient was related to abrupt mental status changes, onset of sialorrhea, myoclonus, and/or need for ventilatory support. Investigations of altered mental status did not reveal alternative causes and presentations were not consistent with neuroleptic malignant syndrome, other acute neurologic complications, or psychiatric decompensation. All patients improved after clozapine dose reductions allowing for transfer from intensive care units. Using the Naranjo ADR Probability Scale for each case, a probable relation between clozapine toxicity and the infectious and/or inflammatory process was determined. Discussion: Clozapine toxicity may manifest with multiple symptoms, including sedation, sialorrhea, and hypotension. In addition to overdose and drug interactions; infection and/or inflammation may precipitate clozapine toxicity. This may be related to cytokine-mediated inhibition of cytochrome P450 1A2. The likelihood of toxicity via this mechanism has not been well characterized, thus careful monitoring is required for medically ill patients receiving clozapine. Clozapine is extensively bound to the acute phase reactant, α-1 acid glycoprotein, which may unpredictably protect against clinical toxicity. C-reactive protein has also been investigated to relate clozapine toxicity to infection and/or inflammation. Conclusion: Clozapine toxicity developed in 3 patients admitted to a medical setting suspected to be related to infection and/or inflammation. Clinicians should be aware of this potential adverse drug event with clozapine.

ABSTRACT Angiotensin (ANGII) and secretin (SCT) share overlapping, interdependent osmoregulatory functions in brain, where SCT peptide/receptor function is required for ANGII action, yet the molecular basis is unknown. Since receptors for these peptides (AT1aR, SCTR) are coexpressed in osmoregulatory centers, a possible mechanism is formation of a cross‐class receptor heterocomplex. Here, we demonstrate such a complex and its functional importance to modulate signaling. Association of AT1aR with SCTR reduced ability of SCT to stimulate cyclic adenosine monophosphate (cAMP), with signaling augmented in presence of ANGII or constitutively active AT1aR. Several transmembrane (TM) peptides of these receptors were able to affect their conformation within complexes, reducing receptor BRET signals. AT1aR TM1 affected only formation and activity of the heterocomplex, without effect on homomers of either receptor, and reduced SCT‐stimulated cAMP responses in cells expressing both receptors. This peptide was active in vivo by injection into mouse lateral ventricle, thereby suppressing water‐drinking behavior after hyperosmotic shock, similar to SCTR knockouts. This supports the interpretation that active conformation of AT1aR is a key modulator of cAMP responses induced by SCT stimulation of SCTR. The SCTR/AT1aR complex is physiologically important, providing differential signaling to SCT in settings of hyperosmolality or food intake, modulated by differences in levels of ANGII.—Lee, L. T. O., Ng, S. Y. L., Chu, J. Y. S., Sekar, R., Harikumar, K. G., Miller, L. J., Chow, B. K. C. Transmembrane peptides as unique tools to demonstrate the in vivo action of a cross‐class GPCR heterocomplex. FASEB J . 28, 2632–2644 (2014). www.fasebj.org

AbstractPurposeTo identify patient concomitant injury and surgical characteristics associated with 6‐month excellent functional and isokinetic testing results following anterior cruciate ligament (ACL) reconstruction.MethodsPatients that underwent ACL reconstruction by a single surgeon had isokinetic and functional testing performed with excellent 6‐month outcome defined as greater than 85 % in isokinetic strength and 90 % in functional tests (excellent 6‐month group vs. delayed 6‐month group). Patient concomitant injury and surgical factors were then analysed in univariate and multivariate statistical models to assess which characteristics predicted the excellent 6‐month group.ResultsThe 224 patients included 93 males and 131 females, with median age of 22 (range 12–59) years, body mass index (BMI) of 25.4 (range 17–44), and median Tegner activity score of 6 (range 2–10). Fifty‐two patients (23 %) were included in the excellent 6‐month group, while 172 patients (77 %) were in the delayed 6‐month group. In univariate analysis, favourable factors with the excellent 6‐month outcome group were younger age (24 vs. 27; p = 0.01), lower BMI (24.5 vs. 26.2; p = 0.03), and minimal articular cartilage damage (71 vs. 56 %; p = 0.048). In multivariate analysis, a negative effect was observed for patients older than 30 years that had ACL reconstruction with autograft (p = 0.0004).ConclusionFactors significantly associated with excellent 6‐month functional and isokinetic test results following ACL reconstruction included younger age, lower BMI, and minimal cartilage degeneration. The use of allograft was associated with improved functional and strength testing after ACL reconstruction in patients over 30 years of age.Level of evidencePrognostic/therapeutic study, Level III.

ABSTRACT Intron-containing mRNAs are subject to restricted nuclear export in higher eukaryotes. Retroviral replication requires the nucleocytoplasmic transport of both spliced and unspliced RNA transcripts, and RNA export mechanisms of gammaretroviruses are poorly characterized. Here, we report the involvement of the nuclear export receptor NXF1/TAP in the nuclear export of gammaretroviral RNA transcripts. We identified a conserved cis -acting element in the pol gene of gammaretroviruses, including murine leukemia virus (MLV) and xenotropic murine leukemia virus (XMRV), named the CAE (cytoplasmic accumulation element). The CAE enhanced the cytoplasmic accumulation of viral RNA transcripts and the expression of viral proteins without significantly affecting the stability, splicing, or translation efficiency of the transcripts. Insertion of the CAE sequence also facilitated Rev-independent HIV Gag expression. We found that the CAE sequence interacted with NXF1, whereas disruption of NXF1 ablated CAE function. Thus, the CAE sequence mediates the cytoplasmic accumulation of gammaretroviral transcripts in an NXF1-dependent manner. Disruption of NXF1 expression impaired cytoplasmic accumulations of both spliced and unspliced RNA transcripts of XMRV and MLV, resulting in their nuclear retention or degradation. Thus, our results demonstrate that gammaretroviruses use NXF1 for the cytoplasmic accumulation of both spliced and nonspliced viral RNA transcripts. IMPORTANCE Murine leukemia virus (MLV) has been studied as one of the classic models of retrovirology. Although unspliced host messenger RNAs are rarely exported from the nucleus, MLV actively exports unspliced viral RNAs to the cytoplasm. Despite extensive studies, how MLV achieves this difficult task has remained a mystery. Here, we have studied the RNA export mechanism of MLV and found that (i) the genome contains a sequence which supports the efficient nuclear export of viral RNAs, (ii) the cellular factor NXF1 is involved in the nuclear export of both spliced and unspliced viral RNAs, and, finally, (iii) depletion of NXF1 results in nuclear retention or degradation of viral RNAs. Our study provides a novel insight into MLV nuclear export.