Challenging cyclopropanation reactions on non-activated double bonds of fatty esters

Cyclopropanation reactions in the chain of unsaturated fatty esters is a good strategy for the ready preparation of potential monomers for polymerization.

Lung adenocarcinoma in the era of targeted therapies: histological classification, sample prioritization, and predictive biomarkers

The arrival of targeted therapies has presented both a conceptual and a practical challenge in the treatment of patients with advanced non-small cell lung carcinomas (NSCLCs). The relationship of these treatments with specific histologies and predictive biomarkers has made the handling of biopsies the key factor for success. In this study, we highlight the balance between precise histological diagnosis and the practice of conducting multiple predictive assays simultaneously. This can only be achieved where there is a commitment to multidisciplinary working by the tumor board to ensure that a sensible protocol is applied. This proposal for prioritizing samples includes both recent technological advances and the some of the latest discoveries in the molecular classification of NSCLCs.

A comparison of three methods for detecting KRAS mutations in formalin-fixed colorectal cancer specimens

BACKGROUND

KRAS mutation testing is required to select patients with metastatic colorectal cancer (CRC) to receive anti-epidermal growth factor receptor antibodies, but the optimal KRAS mutation test method is uncertain.

METHODS

We conducted a two-site comparison of two commercial KRAS mutation kits - the cobas KRAS Mutation Test and the Qiagen therascreen KRAS Kit - and Sanger sequencing. A panel of 120 CRC specimens was tested with all three methods. The agreement between the cobas test and each of the other methods was assessed. Specimens with discordant results were subjected to quantitative massively parallel pyrosequencing (MPP). DNA blends were tested to determine detection rates at 5% mutant alleles.

RESULTS

Reproducibility of the cobas test between sites was 98%. Six mutations were detected by cobas that were not detected by Sanger, and five were confirmed by MPP. The cobas test detected eight mutations which were not detected by the therascreen test, and seven were confirmed by MPP. Detection rates with 5% mutant DNA blends were 100% for the cobas and therascreen tests and 19% for Sanger.

CONCLUSION

The cobas test was reproducible between sites, and detected several mutations that were not detected by the therascreen test or Sanger. Sanger sequencing had poor sensitivity for low levels of mutation.

A preclinical and clinical study of mycophenolate mofetil in pancreatic cancer

A high throughput screening for anticancer activity of FDA approved drugs identified mycophenolic acid (MPA), an inhibitor of inositol monophosphate dehydrogenase (IMPDH) as an active agent with an antiangiogenesis mode of action. Exposure of pancreatic cancer cell lines to MPA resulted in growth inhibition and reduced the expression of VEGF that was reversed by supplementing the media with guanosine supporting and IMPDH-dependant mechanism. In preclinical in vivo study, MPA showed a moderate inhibition of tumor growth in a panel of 6 human derived pancreatic cancer xenografts but reduced the expression of VEGF. To investigate the effects of MPA in human pancreatic cancer, a total of 12 patients with resectable pancreatic cancer (PDA) received increasing doses of mycophenolate mofetil (MMF) in cohorts of 6 patients each from 5-15 days prior to surgical resection. Treatment was well tolerated with one episode of grade 1 muscle pain, one episode of grade 2 lymphopenia (2 gr/day dose) and one episode of grade 2 elevantion in LFT (all in the 2 gr./day dose). Patients recovered from surgery uneventfully with no increased post-operative complications. Assessment of CD31, VEGF, and TUNEL in resected specimens compared to a non treated control of 6 patients showed no significant variations in any of the study endpoints. In conclusion, this study shows the feasibility of translating a preclinical observation to the clinical setting and to explore a drug mechanism of action in patients. MPA, however, did not show any hints of antiangiogenesis of anticancer clinical activity questioning if this agent should be further developed in PDA.

Abstract P1-15-06: Incidence of HER2 Positive Quantified by FISH in Ductal Breast Carcinoma In Situ

Purpose: The Her2/neu gene is amplified and/or its protein is overexpressed in 15-25% of invasive breast cancer, but in Ductal Carcinoma In Situ (DCIS) this expression is highly increased (60-80%). We review our rate of DCIS with Her2 amplified in a prospective series of women with new diagnosis of DCIS. Methods: Patients with new diagnosis of DCIS by biopsy were studied. The status of Her2 was evaluated by fluorescence in situ hybridization (Vysis path vision HER-2 DNA probe kit) and was considered amplified if the ratio HER2/CEP17 was >2.0. The status of estrogen and progesterone receptors were analyzed by inmunohistochemistry (IHQ). Data evaluating architectural pattern and histological grade were also collected. Results: Data from 53 patients with DCIS were included (two patients with combined invasive ductal carcinoma detected at time of surgery and 51 cases of pure DCIS). HER2 was amplified in 20 patients (37%), with HER2/CEP17 ratios between 2.16 to 14.00. A total of 29 patients had grade III DCIS, and of those 18 (62%) had Her2 amplified. 17 patients (32%) were estrogen and progesterone receptors negative (10 with Her2 amplified). We have not observed any correlation about architectural pattern (comedo, cribriform, micropapillary, solid/necrotic) and amplification of Her2. Conclusion: In our series of DCIS patients the Her2 amplification was less commonly found compared to prior studies (37% vs >60%). Most of DCIS were grade 3 (90%) and no relation was found among the architectural pattern and amplification of Her2.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-15-06.

Expression signatures in lung cancer reveal a profile for EGFR-mutant tumours and identify selective PIK3CA overexpression by gene amplification

The development of targeted therapies creates a need to discriminate tumours accurately by their histological and genetic characteristics. Here, we aim to identify gene expression profiles and single markers that recapitulate the pathological and genetic background of non-small cell lung cancer (NSCLC). We performed cDNA microarray analysis on a series of 69 NSCLCs, with known mutation status for important genes, and six normal lung tissues. Unsupervised cluster analysis segregated normal lungs from lung tumours and lung tumours according to their histopathology and the presence of EGFR mutations. Several transcripts were highly overexpressed (by approximately 20 times) in squamous cell carcinomas (SCCs) relative to adenocarcinomas (ACs) and confirmed by immunohistochemistry in an independent cohort of 75 lung tumours. Expression of 13 genes constituted the most prominent hallmarks of EGFR-mutant tumours, including increased levels of proline dehydrogenase (PRODH) and down-regulation of X-box binding protein 1 (XBP1). No genes were differentially expressed, with a fold change >or= 4 or <or=0.25 and a significance level of 5% false-discovery rate, in tumours carrying mutations of TP53 or KRAS. In addition, we organized gene expression data by the position of each gene in the chromosome and observed a cluster of highly expressed genes in chromosome 3q, including PIK3CA, that was characteristic of SCCs. FISH analysis demonstrated a strong statistically significant association between increased levels of PIK3CA expression in these tumours and gene amplification (p < 0.0001; t-test). In conclusion, histopathological phenotypes and, likely, the presence of EGFR mutations confer lung tumours with a marked pattern of gene expression. Moreover, our cDNA microarray analysis identified increased PIK3CA expression due to gene amplification in lung squamous cell carcinomas: this may represent a marker of sensitivity to therapy with PI3K inhibitors.