Development of non-peptide ligands of growth factor receptor-bound protein 2-SRC homology 2 domain using molecular modeling and NMR spectroscopy

We report a novel series of non-peptide ligands that inhibit the growth factor receptor-bound protein 2 (Grb2)-Src homology 2 (SH2) domain binding, designed using a combined computational and NMR-driven approach. We have identified a new lead compound, 1n (IC(50) = 56 μM), which is cytotoxic in HER2-positive breast cancer cells and disrupts the interaction between HER2 and Grb2. Thus, 1n can be used as a scaffold for the development of efficient Grb2-SH2 domain binding inhibitors.     

State-of-the-art MS technology applications in lung disease

Two frontline MS technologies, which have recently gained much attention, are discussed within the scope of this review. Besides a brief summary on the contemporary state of lung cancer and chronic obstructive pulmonary disease, the principles of multiple reaction monitoring and matrix assisted laser desorption ionization (MALDI) MS imaging are presented. A comprehensive overview of quantitative mass spectrometry applications is provided, covering multiple reaction monitoring assay developments for analysis of proteins (biomarkers) and low-molecular-weight compounds (drugs) with a special focus on the disease areas of lung cancer and chronic obstructive pulmonary disease. The MALDI-MS imaging applications are discussed similarly, providing references to studies conducted on lung tissues in order to localize drug compounds and protein biomarkers.     

Impact of the incorporation of tyrosine kinase inhibitor agents on the treatment of patients with a diagnosis of advanced renal cell carcinoma: study based on experience at the Hospital Universitario Central de Asturias

Introduction

For nearly the past two decades, cytokines (CKs) have been the only systemic treatment option available for advanced renal cell carcinoma (RCC). In recent years, tyrosine kinase inhibitors (TKIs) have demonstrated clinical activity on this tumour. Our purpose is to describe one centre’s experience with the use of CKs and TKIs in the treatment of patients with advanced RCC.

Materials and methods

This study was designed as a retrospective chart review of RCC patients who were treated with CKs and/or TKIs in our department between July 1996 and June 2008. Efficacy and toxicity were assessed using World Health Organization (WHO) criteria. The Kaplan-Meier method was used to estimate progression-free (PFS) and overall (OS) survival.

Results

Ninety-four patients were classified into three groups depending on the modality of treatment administered: 46 were treated with CKs alone and/or chemotherapy (27 with immunotherapy, one with chemotherapy and 18 with both), 28 with TKIs alone (25 with sunitinib and 13 with sorafenib) and 20 with TKIs in second-line treatment following failure with CKs (17 with sunitinib, eight with sorafenib, four with bevacizumab and one with lapatinib). The median age was 60 years in the CK group and 65 and 62, respectively, in TKI in first and second-line treatment groups. Eighty-five percent of patients treated with CKs and 75% in the TKI group in first-line treatment and 80% in second-line treatment were men. Overall, 89% of patients had favourable risk, and 11% had intermediate risk. All patients were considered evaluable for toxicity. The main grade 3–4 (%) toxicity was asthenia for both groups, (ten in TKIs and 15 in CKs). Other grade 1–2 toxicities were mucositis (39), bleeding (8), hypertension (19), skin toxicity (33) and hypothyroidism (12.5) associated with TKIs; and anaemia (33), cough (29), asthenia (39) and emesis (14) associated with CKs. The objective response rate among 80 patients evaluable for activity was 10.6% with CKs and 46.5% and 35%, respectively, with TKIs in first- and second-line treatments. Disease stabilisation with CKs was recorded at 59% of patients and with TKIs 25% and 50% in first- and second-line treatment groups, respectively. The median progression-free survival (PFS) with CKs was 122 days [95% confidence interval (CI) 82–162] and with TKIs 201 days (65–337) in the firstand 346 days (256–436) in second-line treatment groups. The median overall survival (OS) was 229 days (142–316) and 2,074 days (1,152–2,996) for patients treated with CKs and TKIs.

Conclusions

Our results are in line with the activity and survival rates previously reported in the literature regarding the use of TKIs for patients with advanced RCC in first- and second-line treatment, which has demonstrated an acceptable toxicity level.     

Differential expression profiling analyses identifies downregulation of 1p, 6q, and 14q genes and overexpression of 6p histone cluster 1 genes as markers of recurrence in meningiomas

The majority of meningiomas are probably benign but a number of tumors display considerable histological and/or clinical aggressivity, sometimes with unexpectedly high recurrence rates after radical removal. Understanding the potential behavior of these tumors in individual patients is critical for rational therapeutic decision-making. This study aimed to identify gene expression profiles and candidate markers associated with original and recurrent meningiomas. Unsupervised hierarchical clustering of the samples confirmed 2 main groups of meningiomas with distinct clinical behaviors. The gene expression profiling study identified genes and pathways potentially associated with meningioma recurrence, revealing an overall lower level of gene expression. The differential gene expression profiling analyses of original and recurrent meningiomas identified 425 known genes and expressed sequence tags related to meningioma recurrence, with SFRP1 (8p12), TMEM30B (14q23), and CTGF (6q23) showing the most disparate expression. Most of the differentially expressed genes were located at 1p, 6q, and 14q and were underexpressed in recurrences. Loss of such chromosomal regions has previously been associated with a higher risk of meningioma recurrence or malignant progression. Thus, at these locations, we propose the existence of novel candidate genes that could be involved in meningioma recurrence. In addition, the overexpression of genes of histone cluster 1 (6p) in recurrent meningiomas is reported here for the first time. Finally, the altered genes related to meningioma recurrence are involved in pathways such as Notch, TGFβ, and Wnt, as described previously, and in other pathways such as cell cycle, oxidative phosphorylation, PPAR, and PDGF, not related before to meningioma recurrence.     

Chromatin remodelling and DNA repair genes are frequently mutated in endometrioid endometrial carcinoma

In developed countries, endometrial carcinoma is the most common cancer that affects the female genital tract. Endometrial carcinoma is divided into two main histological types, type I or endometrioid and type II or non‐endometrioid, each of which have characteristic, although not exclusive, molecular alterations and mutational profiles. Nevertheless, information about the implication and relevance of some of these genes in this disease is lacking. We sought here to identify new recurrently mutated genes in endometrioid cancers that play a role in tumourigenesis and that influence the clinical outcome. We focused on low‐grade, non‐ultramutated tumours as these tumours have a worse prognosis than the ultramutated POLE‐positive endometrioid endometrial carcinomas (EECs). We performed exome‐sequencing of 11 EECs with matched normal tissue and subsequently validated 15 candidate genes in 76 samples. For the first time, we show that mutations in chromatin remodelling‐related genes (KMT2D, KMT2C, SETD1B and BCOR) and in DNA‐repair‐related genes (BRCA1, BRCA2, RAD50 and CHD4) are frequent in this subtype of endometrial cancer. The alterations to these genes occurred with frequencies ranging from 35.5% for KMT2D to 10.5% for BRCA1 and BCOR, with some showing a tendency toward co‐occurrence (RAD50‐KMT2D and RAD50‐SETD1B). All these genes harboured specific mutational hotspots. In addition, the mutational status of KMT2C, KMT2D and SETD1B helps to predict the degree of myometrial invasion, a critical prognostic feature. These results highlight the possible implication of these genes in this disease, creating opportunities for new therapeutic approaches.     

Differential diagnosis of IgM MGUS and WM according to B-lymphoid infiltration by morphology and flow cytometry

The distinction between IgM monoclonal gammopathy of undetermined significance (MGUS), asymptomatic Waldenstrom's macroglobulinemia (WM; aWM), and symptomatic WM (sWM) relies on two features: the presence of infiltration by lymphoplasmacytic lymphoma in the bone marrow (BM) biopsy and the existence of signs or symptoms attributable to the disease. Nevertheless, some patients lack a BM biopsy or it is not conclusive for diagnosis. In this study we have investigated 94 patients with IgM monoclonal gammopathies, in which a BM trephine biopsy and morphological and flow cytometry (FCM) evaluation of BM aspirate were available at diagnosis. We found a clear correlation between BM infiltration of B-lymphocytes assessed by morphology and by FCM with a Pearson correlation of 0.62 (P<.001). Moreover, in the absence of a BM trephine biopsy, the cut-off points that would help in the differential diagnosis between MGUS, aWM, and sWM would be 20% for morphology and 5% for FCM, both assessed in the BM aspirate.     

HER2 status in breast cancer: experience of a Spanish National Reference Centre

Background  

Accurate HER2 testing is of great clinical value for the identification of breast cancer patients who are eligible for trastuzumab therapy. The aim of this study is to review breast carcinomas diagnosed from 2001 to 2007 at a Spanish National Reference Centre for HER2 testing, evaluating the agreement between HER2 immunohistochemical (IHC) tests and fluorescence in situ hybridisation (FISH) tests.     

Gene profiling in breast cancer: time to move forward

Gene signatures may complement clinical and pathological factors to predict prognosis and response to therapy in patients with breast cancer, and can also sub-classify these tumours into entities with different biology and treatment requirements. A number of prognostic gene signatures are commercially available at this moment and two of them have entered phase III evaluation. Specific signatures are also being assessed to predict response to a number of drug therapies. The combined use of prognostic, predictive and subtype-defining signatures will guide therapeutic decisions in the future and will facilitate development of targeted drugs in specific groups of patients. However, cost-utility issues and some technical limitations have hindered widespread adoption of gene profiling. Gene signatures will become part of the routine clinical workup only if they help making clinical decisions. The first step to achieve this will consist of the inclusion of gene signatures in the design of clinical trials with new drugs.     

Lead acetate does not inhibit dimethylnitrosamine activation and interacts with phenobarbital which is genotoxic in the ST cross of the Drosophila wing spot test

Lead acetate (PbAc) is known to inhibit the synthesis of the heme group, needed for hemeproteins like Cytochromes P450 (CYP450s). Dimethylnitrosamine (DMN) requires metabolic activation by CYP450s. The Drosophila wing spot test was performed to establish whether PbAc inhibits DMN activation in the standard (ST) and high bioactivation (HB) crosses, with different levels of CYP450s. Phenobarbital (PH) was used as an antagonist for its ability to induce CYP450s synthesis. PbAc (0.01, 0.1, 1.0 mM) produced significant small spots frequencies in the ST cross, indicating a possible genotoxic activity, however, the total spots frequency was negative at all concentrations. DMN (0.076 mM) was genotoxic in both crosses; surprisingly, PH (12 mM) was genotoxic and the PH-DMN treatment resulted synergic in the ST cross. Interestingly, the PbAc-PH pre-co-treatments showed a possible interaction in the ST cross. The GC-MS analysis showed a drop in the PH content as the PbAc concentration increased. PbAc also seemed to inhibit the genotoxic activity of PH, except at 0.01 mM. It is concluded that PbAc does not inhibit DMN activation by CYP450s in both crosses since it exerted a clear genotoxicity and that PH is genotoxic and interacts with PbAc in the ST but not the HB cross.     

Cognitive enhancers for facilitating drug cue extinction: insights from animal models

Given the success of cue exposure (extinction) therapy combined with a cognitive enhancer for reducing anxiety, it is anticipated that this approach will prove more efficacious than exposure therapy alone in preventing relapse in individuals with substance use disorders. Several factors may undermine the efficacy of exposure therapy for substance use disorders, but we suspect that neurocognitive impairments associated with chronic drug use are an important contributing factor. Numerous insights on these issues are gained from research using animal models of addiction. In this review, the relationship between brain sites whose learning, memory and executive functions are impaired by chronic drug use and brain sites that are important for effective drug cue extinction learning is explored first. This is followed by an overview of animal research showing improved treatment outcome for drug addiction (e.g. alcohol, amphetamine, cocaine, heroin) when explicit extinction training is conducted in combination with acute dosing of a cognitive-enhancing drug. The mechanism by which cognitive enhancers are thought to exert their benefits is by facilitating consolidation of drug cue extinction memory after activation of glutamatergic receptors. Based on the encouraging work in animals, factors that may be important for the treatment of drug addiction are considered.