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.

Implementing a comprehensive approach for evaluating significance and disturbance in protected karst areas to guide management strategies

Many environmental studies have acquired an almost exclusively biotic perspective over the years, neglecting important key land characteristics like those of a geological and hydrological nature. This situation leads to incomplete, and even inappropriate, management strategies, particularly unjustified in the case of karst environments which form the basis of important protected areas around the world and are inherently very fragile environments compared to other natural systems. This study presents a holistic methodological approach to analyse the level of significance and disturbance in the Natural Park of Aralar (Basque Country, northern Spain) using two standardized indices: zonal Karst Significance Index (KSIZ) and zonal Karst Disturbance Index (KDIZ). The distribution of both indices in the park is based on the Geographic Information System (GIS). Thus, thematic maps regarding geological, geomorphological, biological, hydrological and cultural aspects provide the essential data for this work. The obtained results enable us to recognize the most significant and disturbed sectors of the park. These indices are subsequently combined to generate the Priority Management Index (PMI), which determine the different management needs of the territory. This comprehensive information not only serves efforts to better manage protected karst areas, but also to provide a snapshot view of the researched area to compare achieved results over time.

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 EGFR mutation testing methods in lung carcinoma: direct sequencing, real-time PCR and immunohistochemistry

The objective of this study is to compare two EGFR testing methodologies (a commercial real-time PCR kit and a specific EGFR mutant immunohistochemistry), with direct sequencing and to investigate the limit of detection (LOD) of both PCR-based methods. We identified EGFR mutations in 21 (16%) of the 136 tumours analyzed by direct sequencing. Interestingly, the Therascreen EGFR Mutation Test kit was able to characterize as wild-type one tumour that could not be analyzed by direct sequencing of the PCR product. We then compared the LOD of the kit and that of direct sequencing using the available mutant tumours. The kit was able to detect the presence of a mutation in a 1% dilution of the total DNA in nine of the 18 tumours (50%), which tested positive with the real-time quantitative PCR method. In all cases, EGFR mutation was identified at a dilution of 5%. Where the mutant DNA represented 30% of the total DNA, sequencing was able to detect mutations in 12 out of 19 cases (63%). Additional experiments with genetically defined standards (EGFR ΔE746-A750/+ and EGFR L858R/+) yielded similar results. Immunohistochemistry (IHC) staining with exon 19-specific antibody was seen in eight out of nine cases with E746-A750del detected by direct sequencing. Neither of the two tumours with complex deletions were positive. Of the five L858R-mutated tumours detected by the PCR methods, only two were positive for the exon 21-specific antibody. The specificity was 100% for both antibodies. The LOD of the real-time PCR method was lower than that of direct sequencing. The mutation specific IHC produced excellent specificity.

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.

Hybridization for human epidermal growth factor receptor 2 testing in gastric carcinoma: a comparison of fluorescence in-situ hybridization with a novel fully automated dual-colour silver in-situ hybridization method

Aims:

Amplification of the human epidermal growth factor receptor 2 (HER2) gene has been reported in gastric carcinoma (GC). Accordingly, trastuzumab plus chemotherapy has recently become the new standard treatment for HER2-positive advanced GCs. The aim was to compare the alleged gold standard for hybridization [fluorescence in-situ hybridization (FISH)] with a novel, fully automated brightfield dual-colour silver-enhanced in-situ hybridization (SISH) method.

Methods and results:

The studies series was comprised of 166 GC samples. Additionally, tumours with discordant results obtained by FISH and SISH were analysed by real-time quantitative polymerase chain reaction (PCR) with the LightMix kit HER-2/neu. Of the samples, 17.5% and 21% were amplified by FISH and SISH, respectively. Heterogeneity was identified in up to 52% of cases. In 96.4% of cases, FISH showed the same results as SISH. All six discordant cases were positive by SISH and negative by FISH. On review of the FISH slides, all contradictory cases were polysomic and were confirmed to be negative for amplification by real-time PCR. Interestingly, all ratios in this latter group were between 2.06 and 2.50, so setting the cut-off for amplification at ≥3 resulted in perfect concordance.

Conclusions:

Dual-colour SISH represents a novel method for the determination of HER2 status in GC.

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.

The use of P63 immunohistochemistry for the identification of squamous cell carcinoma of the lung

Introduction

While some targeted agents should not be used in squamous cell carcinomas (SCCs), other agents might preferably target SCCs. In a previous microarray study, one of the top differentially expressed genes between adenocarcinomas (ACs) and SCCs is P63. It is a well-known marker of squamous differentiation, but surprisingly, its expression is not widely used for this purpose. Our goals in this study were (1) to further confirm our microarray data, (2) to analize the value of P63 immunohistochemistry (IHC) in reducing the number of large cell carcinoma (LCC) diagnoses in surgical specimens, and (3) to investigate the potential of P63 IHC to minimize the proportion of “carcinoma NOS (not otherwise specified)” in a prospective series of small tumor samples.

Methods

With these goals in mind, we studied (1) a tissue-microarray comprising 33 ACs and 99 SCCs on which we performed P63 IHC, (2) a series of 20 surgically resected LCCs studied for P63 and TTF-1 IHC, and (3) a prospective cohort of 66 small thoracic samples, including 32 carcinoma NOS, that were further classified by the result of P63 and TTF-1 IHC.

Results

The results in the three independent cohorts were as follows: (1) P63 IHC was differentially expressed in SCCs when compared to ACs (p<0.0001); (2) half of the 20 (50%) LCCs were positive for P63 and were reclassified as SCCs; and (3) all P63 positive cases (34%) were diagnosed as SCCs.

Conclusions

P63 IHC is useful for the identification of lung SCCs.

A commercial real-time PCR kit provides greater sensitivity than direct sequencing to detect KRAS mutations: a morphology-based approach in colorectal carcinoma

KRAS mutation testing has become a standard procedure in the management of patients with carcinomas. The most frequently used method for KRAS testing is direct sequencing of PCR products. The development of commercial real-time quantitative PCR kits offers a useful alternative since they are in theory much more sensitive than direct sequencing and they avoid post- PCR handling. We present our experience as a reference center for the study of KRAS mutations, comparing direct sequencing and the use of a commercial real-time quantitative PCR kit, as well as determining the sensitivity of both procedures in clinical practice. The TheraScreen K-RAS Mutation Kit identified mutations in 75 (44%) of the 170 tumors. Three cases were tested positive using TheraScreen K-RAS Mutation Kit and negative by direct sequencing. We then compared the sensitivity of the kit and that of direct sequencing using 74 mutant tumors. The kit was able to detect the presence of a mutation in a 1% dilution of the total DNA in 13.5% of the tumors and, in 84%, KRAS mutation was identified at a dilution of 5%. Sequencing was able to detect KRAS mutations when the mutant DNA represented 10% of the total DNA in 20/74 (27%) of the tumors. When the mutant DNA represented 30% of the total DNA, sequencing could detect mutations in 56/74 (76%).

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.