A potential tumor suppressor role for Hic1 in breast cancer through transcriptional repression of ephrin-A1

The tumor suppressor gene hypermethylated in cancer 1 (HIC1), which encodes a transcriptional repressor, is epigenetically inactivated in various human cancers. In this study, we show that HIC1 is a direct transcriptional repressor of the gene encoding ephrin-A1, a cell surface ligand implicated in the pathogenesis of epithelial cancers. We also show that mouse embryos lacking both Hic1 alleles manifest developmental defects spatially associated with the misexpression of ephrin-A1, and that overexpression of ephrin-A1 is a feature of tumors arising in Hic1 heterozygous mice in which the remaining wild-type allele is epigenetically silenced. In breast cancer, we find that ephrin-A1 expression is common in vivo, but that in cell culture, expression of the EphA receptors is predominant. Restoration of HIC1 function in breast cancer cells leads to a reduction in tumor growth in vivo, an effect that can be partially rescued by co-overexpression of ephrin-A1. Interestingly, overexpression of ephrin-A1 in vitro triggers downregulation of EphA2 and EphA4 levels, resulting in an expression pattern similar to that seen in vivo. We conclude that Hic1 spatially restricts ephrin-A1 expression in development, and that upregulated expression of ephrin-A1 resulting from epigenetic silencing of HIC1 in cancer cells may be an important mechanism in epithelial malignancy.

Combined detection of p53, p16, Rb, and EGFR mutations in lung cancer by suspension microarray

Mutations of some contributing factors (p53, p16, Rb, and EGFR) are believed to affect diagnosis and drug resistance of lung cancer. We evaluated the efficacy of a multimarker panel for molecular diagnosis of lung cancer, using a high-throughput suspension microarray. One hundred and twenty-five lung cancer specimens and 30 tumor-free lung tissue samples were assayed by multiplex polymerase chain reaction with specific probes designed to detect hot-spot mutations in p53, p16, Rb, and EGFR. The mutation rates of p53, p16, Rb, or EGFR in the lung cancer specimens were 36.8, 15.2, 11.2, and 18.4%, respectively. Inclusion of four markers elevated sensitivity to 68.0%. The specificity and accuracy of four-marker detection were 90.0 and 72.3%, and the mutation rates of this panel in stage I, stage II and stage III disease were 62.2, 65.9 and 75.0%, respectively. Mutation at p16 occurred more frequently in non-small cell lung cancer (19.3%) than in small cell lung cancer (5.4%); while the mutation rate of Rb was 32.4% in small cell lung cancer versus 2.3% in non-small cell lung cancer. We conclude that simultaneous detection of p53, Rb, p16, and EGFR in a suspension microarray facilitates rapid diagnosis of lung cancer.

Characterization of the sensitivity of a TCB laplacian sensor for surface EEnG recordings

The improvement of the quality of electroenterogram (EEnG) recordings on abdominal surface could lead to a non-invasive technique to diagnose intestinal motility dysfunctions. In this context, the use of coaxial active electrodes, which permit to record the laplacian potential, can help to achieve such signal enhancement. In this paper, we present a methodology to obtain the maps of sensitivity of this kind of electrodes to pick up the activity of electric dipoles of different orientations. The proposed methodology employs mathematical models, as well as experimental studies (phantoms) to check the theoretical results. The mathematical model of the electrode, and of the human abdomen is developed by means of ANSYS. A simplified physical model is formed by real ring electrodes, a methacrylate tank of size 50 x 50 x 50 cm filled with a saltwater mixture of 2.5 g/l concentration, and moving electric dipoles made by wires of 0.3 mm in diameter. Sensitivity of the sensor is obtained for different depths and different axial distances of vertical and horizontal dipoles. Preliminary results of tripolar ring electrodes in bipolar configuration (TCB) are shown. The obtained results prove the agreement between mathematical and experimental results. The validated model will allow us to study the behavior of laplacian ring electrodes of different dimensions and materials to record the EEnG activity and to analyze the influence of the abdominal layers.

Synthesis of zeolite Li-ABW from fly ash by fusion method

The zeolite Li-ABW was synthesized by fusion method using fly ash as raw material. It comprised alkaline fusion followed by hydrothermal treatment in LiOH x H2O medium. Crystallinity of zeolite as high as 97.8% was attained under the following conditions: LiOH x H2O concentration, 3M; hydrothermal temperature, 180 degrees C; the corresponding aging time, 12 h. The content of Li-ABW increased at the expense of lithium aluminum silicate or quartz with an increase of LiOH x H2O concentration. With increasing hydrothermal temperature and aging time, the soluble species re-crystallized and crystalline phase transformation between different zeolites was observed. Scanning electron microscopy (SEM) observation revealed that the obtained zeolite Li-ABW was a rod-like crystal. The pore size distribution curve indicated the presence of mesopores.

Koilocytes indicate a role for human papilloma virus in breast cancer

BACKGROUND

High-risk human papilloma viruses (HPVs) are candidates as causal viruses in breast cancer. The scientific challenge is to determine whether HPVs are causal and not merely passengers or parasites. Studies of HPV-related koilocytes in breast cancer offer an opportunity to address this crucial issue. Koilocytes are epithelial cells characterised by perinuclear haloes surrounding condensed nuclei and are commonly present in cervical intraepithelial neoplasia. Koilocytosis is accepted as pathognomonic (characteristic of a particular disease) of HPV infection. The aim of this investigation is to determine whether putative koilocytes in normal and malignant breast tissues are because of HPV infection.

METHODS

Archival formalin-fixed normal and malignant breast specimens were investigated by histology, in situ PCR with confirmation of the findings by standard PCR and sequencing of the products, plus immunohistochemistry to identify HPV E6 oncoproteins.

RESULTS

human papilloma virus-associated koilocytes were present in normal breast skin and lobules and in the breast skin and cancer tissue of patients with ductal carcinoma in situ (DCIS) and invasive ductal carcinomas (IDCs).

INTERPRETATION

As koilocytes are known to be the precursors of some HPV-associated cervical cancer, it follows that HPVs may be causally associated with breast cancer.

Schottky junction photovoltaic devices based on CdS single nanobelts

Schottky junction photovoltaic (PV) devices were fabricated on single CdS nanobelts (NBs). Au was used as the Schottky contact, and In/Au was used as the ohmic contact to CdS NB. Typically, the Schottky junction exhibits a well-defined rectifying behavior in the dark with a rectification ratio greater than 10(3) at +/- 0.3 V; and the PV device exhibits a clear PV behavior with an open circuit photovoltage of about 0.16 V, a short circuit current of about 23.8 pA, a maximum output power of about 1.6 pW, and a fill factor of 42%. Moreover, the output power can be multiplied by connecting two or more of the Schottky junction PV devices, made on a single CdS NB, in parallel or in series. This study demonstrates that the 1D Schottky junction PV devices, which have the merits of low cost, easy fabrication and material universality, can be an important candidate for power sources in nano-optoelectronic systems.

The impact of iodine excess on thyroid hormone biosynthesis and metabolism in rats

Thyroid function ultimately depends on appropriate iodine supply to the gland. There is a complex series of checks and balances that the thyroid uses to control the orderly utilization of iodine for hormone synthesis. The aim of our study is to evaluate the mechanism underlying the effect of iodine excess on thyroid hormone metabolism. Based on the successful establishment of animal models of normal-iodine (NI) and different degrees of high-iodine (HI) intake in Wistar rats, the content of monoiodotyrosine (MIT), diiodotyrosine (DIT), T(4), and T(3) in thyroid tissues, the activity of thyroidal type 1 deiodinase (D1) and its (Dio1) mRNA expression level were measured. Results showed that, in the case of iodine excess, the biosynthesis of both MIT and DIT, especially DIT, was increased. There was an obvious tendency of decreasing in MIT/DIT ratio with increased doses of iodine intake. In addition, iodine excess greatly inhibited thyroidal D1 activity and mRNA expression. T(3) was greatly lower in the HI group, while there was no significant difference of T(4) compared with NI group. The T(3)/T(4) ratio was decreased in HI groups, antiparalleled with increased doses of iodine intakes. In conclusion, the increased biosyntheses of DIT relative to MIT and the inhibition of thyroidal Dio1 mRNA expression and D1 activity may be taken as an effective way to protect an organism from impairment caused by too much T(3). These observations provide new insights into the cellular regulation mechanism of thyroid hormones under physiological and pathological conditions.

Phase IIb trial of fluorouracil, leucovorin, oxaliplatin, and paclitaxel (POF) compared with fluorouracil, feucovorin, and irinotecan (IF) as first-line treatment for advanced gastric cancer (AGC)

e15642

Background: Primary results of POF as 1st and 2nd line treatment for AGC have been presented at ASCO 2007 and 2008. We report here data on the feasibility and the toxicity of POF versus IF(Dank, et al, ASCO 2005) in 1st line treatment of AGC. Methods: Patients with previously untreated, advanced, unresectable, and histologically confirmed adenocarcinoma of the gastric or gastroesophageal junction were randomly assigned to POF or IF regiment. Treatment was continued until disease progressed, unacceptable toxicity, or patient choice. Results: 25 patients were entered in this study between March 2007 and July 2007: 13 in the POF group and 12 in the IF group. The median patient age was 55 years (range, 36 to 67 years), 18 were males and 7 were females. No complete response was observed. The response rate was 62.5% (POF) and 33.3% (IF) respectively. At a median follow-up of 285 days, 7(POF) versus 6(IF) patients were still alive. Hematological toxicity was the most frequent toxicity in both groups. Grade 3 to 4 neutropenia were 38.5% (POF) versus 8.3% (IF). Diarrhea was found 0% and 8.3% in POF and IF group respectively. No grade 3 peripheral neurotoxicity was observed. Conclusions: Compared with IF regiment, POF could also be used as first-line treatment for AGC with acceptable safety profile, good efficacy, and more encouraging results.

No significant financial relationships to disclose.

Oxytocin receptor expressed on the smooth muscle mediates the excitatory effect of oxytocin on gastric motility in rats

The aim of this study was to localize oxytocin receptor (OTR) in the stomach and to investigate the effect of OT on gastric motility in rats. Western blot and immunohistochemistry methods were used to localize OTR in stomach. The motility of stomach was recorded in vivo (recording of the intragastric pressure), in vitro (recording of the contraction of muscle strips) and on isolated smooth muscle cells. OTR was expressed on cells of both circular and longitudinal muscle of stomach. Systemic administration of OT induced an early transient decrease and a subsequent increase on intragastric pressure. Devazepide (1 mg kg(-1), i.v.), a cholecystokinin-1 (CCK(1)) receptor antagonist, completely abolished the transient response but did not influence the subsequent one. OT (10(-9)-10(-6) mol L(-1)) dose-dependently increased the contraction of the muscle strips of gastric body, antrum, and pyloric sphincter, and decreased the average cell length of isolated smooth muscle cells. Tetrodotoxin and atropine did not influence the effect of OT on muscle strips. Pretreatment with atosiban, an OTR antagonist, inhibited the spontaneous contraction of muscle strips and abolished the excitatory effect of OT on the muscle strips and the isolated cells. These results suggest that the OTR is expressed on the smooth muscle of the stomach and mediates excitatory effect of OT on gastric motility.

Phase 1b study of motesanib diphosphate (AMG 706) in combination with paclitaxel or docetaxel for the treatment of locally recurrent, unresectable or metastatic breast cancer

Abstract #4117

Background: Motesanib is a novel oral angiogenesis inhibitor designed to selectively target the tyrosine kinase activity of VEGF 1, 2 and 3; PDGF and Kit receptors. Here we report safety, preliminary efficacy and pharmacokinetics (PK) from an ongoing phase 1b dose-finding study of motesanib plus either paclitaxel (P) or docetaxel (D) in patients (pts) with advanced breast cancer.
 Methods: Eligible pts with ECOG 0 or 1 and ≤1 prior chemotherapy regimen for metastatic breast cancer received (until toxicity or disease progression) escalating doses of motesanib (50 or 125mg) QD orally continuously from day 3 of cycle 1 plus either P (Arm A) at 90mg/m2 on days 1, 8 and 15 of each 28-day cycle; or D (Arm B) at either 100mg/m2 on day 1 of every 21-day cycle or at 75mg/m2 with motesanib maximum tolerated dose (125mg QD). Objective response (OR) per RECIST was assessed every 8 (Arm A) or 6 wks (Arm B).
 Results: To date, 33 pts have received ≥1 dose of motesanib: Arm A, n=10; Arm B, n=23. Median age is 51 (range, 28-66) years. There were 5 DLTs (all grade 3) in 4 pts: abnormal liver function tests and deep vein thrombosis (Arm A, 125mg QD), fatigue (Arm A, 125mg QD), gallbladder enlargement (Arm B, 125mg QD+75mg/m2 D) and migraine (Arm B, 125mg QD). 28 pts (85%) had motesanib-related AEs; the most common were (worst grade): diarrhea, Arm A/B 60%/61% (grade 3, 0%/13%); fatigue, 30%/26% (grade 3, 10%/4%); hypertension, 20%/22% (grade 3, 10%/4%); and nausea, 10%/26% (no grade 3). Treatment-related AEs of interest in Arm A/B included epistaxis (10%/18%; all worst grade 1) and deep vein thrombosis (10%/0%; all worst grade 3). There were no grade 4 or 5 related AEs. Two deaths on study occurred (Arm B; 50 and 125mg QD n=1 each); both were not considered to be motesanib related. Motesanib PK parameters were generally within the range previously described for single-agent motesanib. PK profiles of P and D showed high interpatient variability, with AUC higher in some pts after motesanib coadministration. In pts with measurable disease at baseline (Arms A&B, n=7&18), best OR at time of last data cut-off was: confirmed PR in Arm A n=2 (29%), in Arm B n=5 (28%); SD in Arm A n=2 (29%), in Arm B n=9 (50%); durable SD ≥24 wks in Arm A n=0, in Arm B n=3 (17%). Median (range) duration of response currently is 169 (58-169) days in Arm A and 198 (96-337+) days in Arm B.
 Conclusions: Motesanib combined with P or D appears to be tolerable with evidence of antitumor activity in pts with advanced breast cancer. No marked effect on motesanib PK has been noted with coadministration of either P or D. Updated safety and efficacy data, including PFS, will be presented.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4117.

Are lifetime abstainers the best control group in alcohol epidemiology? On the stability and validity of reported lifetime abstention

Lifetime abstainers have often been recommended as the comparison group in alcohol epidemiology. The objective of this study was to provide insight into the validity and stability of lifetime abstention by using data derived from the National Alcohol Survey, a national probability survey of US households conducted in 1984, and its 2 follow-up surveys conducted in 1990 and 1992. Results indicated that more than half (52.9%; all proportions were weighted to represent the US population) of those who reported never having a drink of any alcoholic beverage in the 1992 survey reported drinking in previous surveys. Depending on assumptions, this difference may result in an underestimation of alcohol-attributable mortality of 2%-15% in men and 2%-22% in women. Sociodemographic factors differentiated those who consistently reported lifetime abstention across surveys from the rest of the study population. Results suggest that using reported lifetime abstainers as a sole comparison group is problematic, especially if reporting is based on 1 measurement only. Establishing multiple measurement points and including irregular lifetime light drinkers with lifetime abstainers as the comparison group are recommended for future epidemiologic studies.