Complete response of a metastatic gastroesophageal adenocarcinoma on irinotecan-based chemotherapy in a dialysis patient

We present the first case report of a complete response of metastatic gastroesophageal cancer in a chronic hemodialysis patient with irinotecan-based chemotherapy. An elderly dialysis patient presented with diffuse liver metastases by a gastroesophageal adenocarcinoma. He received combination chemotherapy with 5 fluorouracil and irinotecan. After six months of chemotherapy, liver scans show complete remission. The principles, practice, and experience of chemotherapy with irinotecan during dialysis are discussed.

Abstract 797: Kinase activity profiling of tumor tissues of different origin

Introduction:

Many new anti-cancer drugs target kinase activity. Unfortunately, methods to monitor the drug effects at the enzymatic level in patient derived tumor tissue are lacking. Here, a novel molecular profiling method for application in biomarker discovery is presented. This method is based on measuring kinase activities in tumor tissue extracts, and involves assessment of inhibition by a drug of interest. This ex vivo activity-based approach is enabled by dynamic peptide microarrays. These arrays comprise of peptides, which are known substrates for phosphorylation by protein kinases. Here we investigated the applicability of this approach in the classification of multiple tumors of different origin.

Method:

Patient-derived fresh frozen tissues of different tumor types (24 breast cancer (BC), 14 non-small cell lung cancer (NSCLC), 12 renal cell carcinomas (RCC)) were used for extraction of total protein in lysis buffer. Dependent on the tissue source, 6 slices of 10 µm were sufficient for 20-100 microarray analyses. Equal amounts of total protein were analyzed for kinase activity on dynamic PamChip peptide microarrays. These arrays comprised 144 or 256 different peptides. A PamChip96 plate format was used, enabling 96 microarray incubations per run. Protein amounts ranging from 1 − 5 µg were used per microarray analysis. Tumor extracts were analysed in the presence and absence of kinase inhibitor drugs (RCC: sorafenib and sunitinib, NSCLC: gefitinib).

Results:

We show here that from different tumors kinase activity profiles could be generated reproducibly (10-15% CV for selected peptides). Control experiments showed protein concentration and ATP dependency. In the RCC experiments different phosphorylation profiles were obtained when the non-tumor tissue was compared to tumor tissue derived from the same patient, showing higher kinase activities in the latter. In addition, inhibitor dependent modulation of the peptide phosphorylations was observed (sorafenib vs. sunitinib). Furthermore, differential kinase activity profiles were obtained that could be correlated to different patient subgroups (BC) or clinical data (long vs. short term survivors; NSCLC).

Conclusion:

A novel molecular profiling approach was successfully applied for classification of different tumors. This approach is based on detection of kinase activities as well as inhibition of kinase activity in tumor tissues. Application of this method in the discovery of biomarkers for diagnosis, prognosis or prediction of drug response is foreseen.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 797.

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.

Multicenter study using paraffin-embedded tumor tissue testing PITX2 DNA methylation as a marker for outcome prediction in tamoxifen-treated, node-negative breast cancer patients

PURPOSE

We recently reported DNA methylation of the paired-like homeodomain transcription factor 2 (PITX2) gene to be strongly correlated with increased risk of recurrence in node-negative, hormone receptor-positive, tamoxifen-treated breast cancer patients using fresh frozen specimens. Aims of the present study were to establish determination of PITX2 methylation for routine analysis in formalin-fixed paraffin-embedded (FFPE) breast cancer tissue and to test PITX2 DNA methylation as a biomarker for outcome prediction in an independent patient cohort.

PATIENTS AND METHODS

Real-time polymerase chain reaction (PCR) technology was validated for FFPE tissue by comparing methylation measurements in FFPE specimens with those in fresh frozen specimens from the same tumor. The impact of PITX2 methylation on time to distant metastasis was then evaluated in FFPE specimens from hormone receptor-positive, node-negative breast cancer patients (n = 399, adjuvant tamoxifen monotherapy).

RESULTS

Reproducibility of the PCR assay in replicate measurements (r(s) > or = 0.95; n = 150) and concordant measurements between fresh frozen and FFPE tissues (r(s) = 0.81; n = 89) were demonstrated. In a multivariate model, PITX2 methylation added significant information (hazard ratio = 2.35; 95% CI, 1.20 to 4.60) to established prognostic factors (tumor size, grade, and age).

CONCLUSION

PITX2 methylation can be reliably assessed by real-time PCR technology in FFPE tissue. Together with our earlier studies, we have accumulated substantial evidence that PITX2 methylation analysis holds promise as a practical assay for routine clinical use to predict outcome in node-negative, tamoxifen-treated breast cancer, which might allow, based on future validation studies, the identification of low-risk patients who may be treated by tamoxifen alone.

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.