Integrated Genomic Profiling of Endocrine Therapy Response in Advanced Breast Cancer

PurposeIn hormone receptor positive breast cancer the response rates for endocrine treatment, i.e. tamoxifen (TAM) or aromatase inhibitors (AIs), are only 50 to 70% in the advanced disease setting. The overall aim of this retrospective study is to identify a molecular signature using integrated genomic profiling to improve prediction of endocrine treatment outcome in the advanced disease setting.ObjectivesA) To compare mRNA expression profiles of TAM- and AI-treated patients and to identify genes and pathways associated with treatment outcome.B) To discover miRNA and mRNA signatures predictive for AI response.Patients and MethodsFresh frozen Estrogen Receptor (ER)-positive primary breast cancer specimens from patients with advanced disease treated with first-line AIs (N=55) or TAM (N=109) were analyzed. Expression profiles of 670 miRNAs and 44K mRNAs were generated using multiplex qRT-PCR and microarrays. Profiles were related to clinical response and time to progression (TTP). Statistical and bio-informatic tools were applied to discover and combine markers into an integrated genomic predictive signature. The nearest centroid prediction method of BRB-ArrayTools (Version3.7.0) was used to assess the predictive value.ResultsThe quality controlled and informative expression profiles of 277 miRNAs and 14112 mRNAs in 50 AI-treated tumors and 10433 mRNAs in 101 TAM-treated tumors were included for further analysis in the discovery phase.Global testing of mRNAs linked to Biocarta pathways demonstrated the involvement of the interferon pathway in endocrine therapy response in both AI- and TAM-treated patients. Using BRB-ArrayTools survival analysis to find genes associated with TTP (P<0.05), we identified 1002 mRNAs in AI-treated and 662 mRNAs in TAM-treated tumors to be significantly related with TTP.The overlap of 40 mRNAs between AI- and TAM-treatment was defined as a mRNA signature for endocrine treatment outcome. In TAM-treated patients this classifier has a 69% accuracy (63% sensitivity, 74% specificity), an odds ratio for clinical benefit of 4.69 (95% CI 1.99-11.05, P<0.001) and a hazard ratio for TTP of 0.17 (95% CI 0.10-0.29, P<0.001). In AI-treated patients, this 40mRNA signature has a performance of 78% accuracy (84% sensitivity, 62% specificity) and significantly predicts clinical benefit (odds ratio = 8.27, 95% CI 2.00-34.3, P=0.004) and TTP (hazard ratio = 0.07, 95% CI 0.02-0.22, P<0.001).After statistical analysis a 16 miRNAs classifier for AI-treatment outcome was identified with a performance of 78% accuracy (89% sensitivity, 46% specificity). This classifier significantly predicts clinical benefit (Odds ratio = 7.07, 95% CI 1.57-31.9, P=0.011) and TTP (hazard ratio = 0.24, 95% CI 0.09-0.61, P=0.003).The genomic mRNA and miRNA signatures are currently integrated and validated in additional samples as well as “in silico” on tumors treated with neo-adjuvant AI (Miller et al, JCO 2009).ConclusionThis is the first study that combines miRNA and mRNA profiling in an attempt to define an integrated genomic signature for endocrine treatment outcome. Additional prospective multicenter studies are needed to confirm the predictive value of this signature.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3029.

Separation of amino acids, their derivatives and enantiomers by impregnated TLC

The present state of TLC with respect to separation of amino acids, their different derivatives and their enantiomers by the technique of impregnation is discussed. The main approaches to impregnation viz. mixing of a suitable reagent with the adsorbent prior to plate-making, immersion of the untreated plate in the solution of impregnating reagent prior to development, and modification of the adsorbent, have been identified and discussed for each class of these compounds. The role of impregnation in resolving enantiomers or in improving the separation of mixtures of amino acids or their derivatives in terms of ion pairing, complex formation, ligand exchange or other steric interactions has been elaborated in each category.

Direct resolution of (+/-)-ephedrine and atropine into their enantiomers by impregnated TLC

Direct resolution of (+/-)-ephedrine and atropine into their enantiomers was achieved by normal-phase thin layer chromatography on silica gel plates impregnated with optically pure L-tartaric acid and L-histidine, respectively, as chiral selectors. The mobile phases enabling successful resolution were different combinations of acetonitrile-methanol-water. The spots were detected with iodine vapours and the detection limits were 2 and 6 microg, respectively, in terms of the racemate. The effects of concentration of the impregnating reagent, temperature and pH on resolution have been studied.

PD98059 attenuates hydrogen peroxide-induced cell death through inhibition of Jun N-Terminal Kinase in HT29 cells

We have investigated the effects of hydrogen peroxide (H(2)O(2)), a potent naturally occurring oxidant on cell signaling and viability in the pluripotent HT29 intestinal cell line. There was a dose-dependent reduction in cell viability upon exposure to H(2)O(2) as measured by the XTT assay. Features of apoptosis were indicated by the findings of PARP and caspase 3 cleavage, as well as changes in cell morphology using phase contrast and nuclear fragmentation using fluorescence microscopy. There was a dose-dependent increase in the activation of p45-JNK, p42/p44-ERK, and p38-HOG. Surprisingly, oxidant-induced cell injury could be attenuated by preincubation with PD98059 to 50% of untreated control cells (P = 0.002). This and UO126, another MEK inhibitor were ably to reproducibly inhibit p45-JNK activation induced by hydrogen peroxide. Transfection with kinase-inactive constructs of JNK and ERK revealed that the improvement in cell viability was due to inhibition of JNK and not ERK. Transient transfections with AP-1 and NF-kappaB luciferase reporter constructs did not reveal any transcriptional activation due to hydrogen peroxide exposure however, in both cases the basal levels of transcriptional activity were suppressed in the presence of PD98059. It is concluded that JNK mediates H(2)O(2)-induced cellular injury in the HT29 cell line, and additionally, we report for the first time that JNK activation can be inhibited by both PD98059 and UO126 at conventional doses used to inhibit MEK.

Multicomponent synthesis of novel amino acid-nucleobase chimeras: a versatile approach to PNA-monomers

This paper describes a multicomponent approach to novel totally protected precursors of PNA-monomers via Ugi 4CC. The obtained bisamides are converted into several partially protected PNA-monomers or derivatives thereof using three different procedures. Methods for hydrolysis are shown to be dependent on the nature of the isocyano component required for Ugi 4CC. Several novel monomers suitable for oligomer synthesis are prepared demonstrating the high versatility of the reaction sequence.

Direct thin layer chromatography enantioresolution of some basic DL-amino acids using a pharmaceutical industry waste as chiral impregnating reagent

Direct enantiomeric resolution of DL-arginine, DL-histidine, DL-lysine, DL-valine and DL-leucine into their enantiomers was achieved by thin layer chromatography (TLC) on silica gel plates impregnated with optically pure (1R, 3R, 5R)-2-azabicyclo[3,3,0]octan-3-carbo-xylic acid (0.011 M) as a chiral selector which is a waste of a pharmaceutical industry. Different combinations of acetonitrile-methanol-water were found to be successful in resolving the DL-amino acids. The spots were detected by ninhydrin (0.2% in acetone) and the detection limit was 0.66 microg.

Can keratin 8 and 17 immunohistochemistry be of diagnostic value in cervical cytology? A feasibility study

BACKGROUND

Based on results from evaluation of tissue sections from premalignant lesions of the uterine cervix, the authors examined the hypothesis that immunostaining of Papanicolaou-stained cytologic smears with monoclonal antibodies to keratins 8 and 17 allows detection of cervical intraepithelial neoplasia (CIN) with progressive potential. They also investigated whether detection of these two keratin subtypes could be of help in the analysis of normal and/or poor quality cytology smears.

METHODS

Sixty-one Papanicolaou-stained smears, representing 25 normal smears, 8 CIN 1, 7 CIN 2, 18 CIN 3, and 3 cervical carcinomas, were stained with CAM 5.2 and E3, which are capable of detecting keratin 8 and 17, respectively. The percentages of immunoreactive normal, metaplastic, dysplastic, and malignant epithelial cells were determined.

RESULTS

In normal cervical smears, keratin 8 was detected in endocervical columnar cells and sporadically in immature squamous metaplastic cells. Keratin 17 was identified in reserve cells and frequently in immature squamous metaplasic cells. In CIN, the number of cases in which keratin 8 was present increased with the severity of the lesion. Keratin 17 was found in the majority of CIN lesions, irrespective of grade. Intensity of immunostaining and number of cells stained per lesion varied and were also not related to the severity of CIN.

CONCLUSIONS

The use of the keratin 8 antibody in normal cervical smears enabled the detection of endocervical cells in cases where they were thought to be absent, particularly in cases with severe inflammation. Staining with keratin 17 enabled the identification of reserve cells or immature metaplastic cells, which were often misinterpreted as parabasal cells. The application of antibodies to these subtypes of keratins in cervical cytology can to a certain extent help in the identification of CIN and may in future be tested in automated screening.

Modified PNAs: a simple method for the synthesis of monomeric building blocks

The synthesis of PNA-monomers with variations in the substitution pattern using the Ugi-Reaction is described. The one-pot procedure leads to new totally protected PNA-monomers which can be selectively cleaved to N-protected monomeric building blocks for PNA synthesis.