Identification of an Optimized Heating and Fast Ion Generation Scheme for the Wendelstein 7-X Stellarator.

A Doppler shifted resonance minority species ion cyclotron range of frequency (ICRF) scheme for heating neutral beam ions has been identified and optimized for the Wendelstein 7-X stellarator. Compared with more conventional methods, the synergetic scheme increases the normalized core collisional power transfer to the background plasma, and induces larger concentrations of energetic ions. Simulations in the intricate 3D magnetic stellarator geometry reveal an energetic distribution function that is only weakly anisotropic, and is thus relevant to fast ion and alpha particle driven Alfvén eigenmode experimental preparation. Quasilinear theory and simulations of the Joint European Torus indicate that the excellent confinement properties are due to increased velocity diffusion from ICRF interaction along the magnetic field lines. Agreement is found between SCENIC simulations and Joint European Torus experimental measurements for the total neutron rate and the energy distribution of the fast ions.

Excitation Mechanism of Low-n Edge Harmonic Oscillations in Edge Localized Mode-Free, High Performance, Tokamak Plasmas.

The excitation mechanism for low-n edge harmonic oscillations in quiescent H-mode regimes is identified analytically. We show that the combined effect of diamagnetic and poloidal magnetohydrodynamic flows, with the constraint of a Doppler-like effect of the ion flow, leads to the stabilization of short wavelength modes, allowing low-n perturbation to grow. The analysis, performed in tokamak toroidal geometry, includes the effects of large edge pressure gradients, associated with the local flattening of the safety factor and diamagnetic flows, sheared parallel and E×B rotation, and a vacuum region between plasma and the ideal metallic wall. The separatrix also is modeled analytically.

Treatment of ALK-rearranged non-small cell lung cancer: A review of the landscape and approach to emerging patterns of treatment resistance in the Australian context.

Since the identification of anaplastic lymphoma kinase (ALK) gene rearrangements in non-small cell lung cancer (NSCLC) in 2005, the treatment of ALK-rearranged NSCLC (ALK+ NSCLC) has evolved at a rapid pace. This molecularly distinct subset of NSCLC has uniquely important biology, clinicopathologic features and mechanisms of drug resistance which impact on the choice of treatment for a patient with this disease. There are multiple ALK tyrosine kinase inhibitors now available in clinical practice with efficacy data continuing to emerge and guide the optimal treatment algorithm. A detailed search of medical databases and clinical trial registries was conducted to capture all relevant articles on this topic enabling an updated detailed overview of the landscape of management of ALK-rearranged NSCLC.

The role of canonical and non-canonical Hedgehog signaling in tumor progression in a mouse model of small cell lung cancer.

Hedgehog (Hh) signaling regulates cell fate and self-renewal in development and cancer. Canonical Hh signaling is mediated by Hh ligand binding to the receptor Patched (Ptch), which in turn activates Gli-mediated transcription through Smoothened (Smo), the molecular target of the Hh pathway inhibitors used as cancer therapeutics. Small cell lung cancer (SCLC) is a common, aggressive malignancy with universally poor prognosis. Although preclinical studies have shown that Hh inhibitors block the self-renewal capacity of SCLC cells, the lack of activating pathway mutations have cast doubt over the significance of these observations. In particular, the existence of autocrine, ligand-dependent Hh signaling in SCLC has been disputed. In a conditional Tp53;Rb1 mutant mouse model of SCLC, we now demonstrate a requirement for the Hh ligand Sonic Hedgehog (Shh) for the progression of SCLC. Conversely, we show that conditional Shh overexpression activates canonical Hh signaling in SCLC cells, and markedly accelerates tumor progression. When compared to mouse SCLC tumors expressing an activating, ligand-independent Smo mutant, tumors overexpressing Shh exhibited marked chromosomal instability and Smoothened-independent upregulation of Cyclin B1, a putative non-canonical arm of the Hh pathway. In turn, we show that overexpression of Cyclin B1 induces chromosomal instability in mouse embryonic fibroblasts lacking both Tp53 and Rb1. These results provide strong support for an autocrine, ligand-dependent model of Hh signaling in SCLC pathogenesis, and reveal a novel role for non-canonical Hh signaling through the induction of chromosomal instability.

Mutant p53 upregulates alpha-1 antitrypsin expression and promotes invasion in lung cancer.

Missense mutations in the TP53 tumor-suppressor gene inactivate its antitumorigenic properties and endow the incipient cells with newly acquired oncogenic properties that drive invasion and metastasis. Although the oncogenic effect of mutant p53 transcriptome has been widely acknowledged, the global influence of mutant p53 on cancer cell proteome remains to be fully elucidated. Here, we show that mutant p53 drives the release of invasive extracellular factors (the 'secretome') that facilitates the invasion of lung cancer cell lines. Proteomic characterization of the secretome from mutant p53-inducible H1299 human non-small cell lung cancer cell line discovered that the mutant p53 drives its oncogenic pathways through modulating the gene expression of numerous targets that are subsequently secreted from the cells. Of these genes, alpha-1 antitrypsin (A1AT) was identified as a critical effector of mutant p53 that drives invasion in vitro and in vivo, together with induction of epithelial-mesenchymal transition markers expression. Mutant p53 upregulated A1AT transcriptionally through the involvement with its family member p63. Conditioned medium containing secreted A1AT enhanced cell invasion, while an A1AT-blocking antibody attenuated the mutant p53-driven migration and invasion. Importantly, high A1AT expression correlated with increased tumor stage, elevated p53 staining and shorter overall survival in lung adenocarcinoma patients. Collectively, these findings suggest that A1AT is an indispensable target of mutant p53 with prognostic and therapeutic potential in mutant p53-expressing tumors.

Alterations of insulin-like growth factor-1 receptor gene copy number and protein expression are common in non-small cell lung cancer.

AIMS: Insulin-like growth factor-1 receptor (IGF1R) is a tyrosine kinase membrane receptor involved in tumourigenesis that may be a potential therapeutic target. We aimed to investigate the incidence and prognostic significance of alterations in IGF1R copy number, and IGF1R protein expression in resected primary non-small cell lung cancer (NSCLC), and lymph node metastases. METHODS: IGF1R gene copy number status was evaluated by chromogenic silver in situ hybridisation and IGF1R protein expression was evaluated by immunohistochemistry in tissue microarray sections from a retrospective cohort of 309 surgically resected NSCLCs and results were compared with clinicopathological features, including EGFR and KRAS mutational status and patient survival. RESULTS: IGF1R gene copy number status was positive (high polysomy or amplification) in 29.2% of NSCLC, and 12.1% exhibited IGF1R gene amplification. High IGF1R expression was found in 28.3%. There was a modest correlation between IGF1R gene copy number and protein expression (r=0.2, p<0.05). Alterations of IGF1R gene copy number and protein expression in primary tumours were significantly associated with alterations in lymph node metastases (p<0.01). High IGF1R gene copy number and protein expression was significantly higher in squamous cell carcinomas (SCC) compared with other subtypes of NSCLC (p<0.05). There were no other associations between IGF1R status and other clinicopathological features including patient age, gender, smoking status, tumour size, stage, grade, EGFR or KRAS mutational status or overall survival. CONCLUSIONS: High IGF1R gene copy number and protein overexpression are frequent in NSCLC, particularly in SCCs, but they are not prognostically relevant.

Correlation of BRAF and NRAS mutation status with outcome, site of distant metastasis and response to chemotherapy in metastatic melanoma.

BACKGROUND: The prognostic significance of BRAF and NRAS mutations in metastatic melanoma patients remains uncertain, with several studies reporting conflicting results, often biased by the inclusion of patients treated with BRAF and MEK (MAPK) inhibitors. We therefore interrogated a historical cohort of patients free of the confounding influence of MAPK inhibitor therapy. METHODS: Patients with available archival tissue first diagnosed with metastatic melanoma between 2002 and 2006 were analysed. Mutational analysis was performed using the OncoCarta Panel. Patient characteristics, treatment outcome and survival were correlated with BRAF/NRAS mutation status. RESULTS: In 193 patients, 92 (48%) melanomas were BRAF-mutant, 39 (20%) were NRAS-mutant and 62 (32%) were wild-type for BRAF/NRAS mutations (wt). There was no difference in response to chemotherapy based on mutation status (35-37%). The distant disease-free interval (DDFI) was significantly shorter in patients with wt melanoma (27.9 months vs 35.1 for BRAF and 49.1 for NRAS) although this was not significant in multivariate analysis. Survival from stage IV melanoma diagnosis was not significantly different based on mutation status. The DDFI was significantly shorter in patients with BRAF(V600K/R) versus BRAF(V600E) melanoma in univariate and multivariate analyses. CONCLUSIONS: BRAF and NRAS mutation status does not influence survival in metastatic melanoma.

Phosphorylated Akt expression is a prognostic marker in early-stage non-small cell lung cancer.

AIMS: To determine the prognostic significance of pAkt expression in order to identify high-risk stage IB patients with non-small cell lung cancer (NSCLC) in an exploratory study. METHODS: We identified 471 consecutive patients with stage IB primary NSCLC according to the American Joint Commission on Cancer 6th edition tumour-node-metastasis (TNM) staging system, who underwent surgical resection between 1990 and 2008. Patients who received neoadjuvant or adjuvant treatments were excluded. Pathology reports were reviewed, and pathological characteristics were extracted. Expression of phosphorylated Akt (pAkt) in both cytoplasmic and nuclear locations was assessed by immunohistochemistry, and clinicopathological factors were analysed against 10-year overall survival using Kaplan-Meier and Cox proportional hazards model. RESULTS: 455 (96.6%) cancers were adequate for pAkt immunohistochemical analysis. The prevalence of pAkt expression in the cytoplasm and nucleus of the cancers was 60.7% and 43.7%, respectively. Patients whose cancers expressed higher levels of cytoplasmic pAkt had a trend towards longer overall survival than those with lower levels (p=0.06). Conversely, patients whose cancers expressed higher levels of nuclear pAkt had a poorer prognosis than those with lower levels of expression (p=0.02). Combined low cytoplasmic/high nuclear expression of pAkt was an independent predictor of overall survival (HR=2.86 (95% CI 1.35 to 6.04); p=0.006) when modelled with age (HR=1.05 (95% CI 1.03 to 1.07); p<0.001), extent of operation (HR=2.11 (95% CI 1.48 to 3.01); p<0.001), visceral pleural invasion (HR=1.63 (95% CI 1.24 to 2.15); p<0.001), gender, tumour size, histopathological type and grade (p>0.05). CONCLUSIONS: Level of expression of pAkt in the cytoplasm and nucleus is an independent prognostic factor that may help to select patients with high-risk disease.

EGFR mutant-specific immunohistochemistry has high specificity and sensitivity for detecting targeted activating EGFR mutations in lung adenocarcinoma.

AIM: We assessed the diagnostic accuracy of epidermal growth factor receptor (EGFR) mutant-specific antibodies for detecting two common activating EGFR mutations. METHODS: Immunohistochemical expression of mutation-specific antibodies against EGFR exon 19 deletion E746-A750 ((c.2235_2249del15 or c.2236_2250del15, p. Glu746_Ala750del) and exon 21 L858R point mutation (c.2573T>G, p.Leu858Arg) were assessed in a cohort of 204 resected early stage node negative lung adenocarcinomas, and protein expression was compared with DNA analysis results from mass spectrometry analysis. RESULTS: Of seven cases with L858R point mutation, six were positive by immunohistochemistry (IHC). There were three false positive cases using L858R IHC (sensitivity 85.7%, specificity 98.5%, positive predictive value 66.7%, negative predictive value 99.5%). All seven E746-A750 exon 19 deletions identified by mutation analysis were positive by IHC. Four additional cases were positive for exon 19 IHC but negative by mutation analysis. The sensitivity of exon 19 IHC for E746-A750 was 100%, specificity 98.0%, positive predictive value 63.6% and negative predictive value 100%. CONCLUSIONS: Mutant-specific EGFR IHC has good specificity and sensitivity for identifying targeted activating EGFR mutations. Although inferior to molecular genetic analysis of the EGFR gene, IHC is highly specific and sensitive for the targeted EGFR mutations. The antibodies are likely to be of clinical value in cases where limited tumour material is available, or in situations where molecular genetic analysis is not readily available.

Tokamak magnetohydrodynamic equilibrium states with axisymmetric boundary and a 3D helical core.

Magnetohydrodynamic (MHD) equilibrium states with imposed axisymmetric boundary are computed in which a spontaneous bifurcation develops to produce an internal three-dimensional (3D) configuration with a helical structure in addition to the standard axisymmetric system. Equilibrium states with similar MHD energy levels are shown to develop very different geometric structures. The helical equilibrium states resemble saturated internal kink mode structures.

Magnetic reconnection triggering magnetohydrodynamic instabilities during a sawtooth crash in a Tokamak plasma.

Thomson scattering measurements with subcentimeter spatial resolution have been made during a sawtooth crash in a Mega Ampere Spherical Tokamak fusion plasma. The unparalleled resolution of the temperature profile has shed new light on the mechanisms that underlie the sawtooth. As magnetic reconnection occurs, the temperature gradient at the island boundary increases. The increased local temperature gradient is sufficient to make the helical core unstable to ideal magnetohydrodynamic instabilities, thought to be responsible for the rapidity of the collapse.

DLEC1 and MLH1 promoter methylation are associated with poor prognosis in non-small cell lung carcinoma.

The significance of chromosome 3p gene alterations in lung cancer is poorly understood. This study set out to investigate promoter methylation in the deleted in lung and oesophageal cancer 1 (DLEC1), MLH1 and other 3p genes in 239 non-small cell lung carcinomas (NSCLC). DLEC1 was methylated in 38.7%, MLH1 in 35.7%, RARbeta in 51.7%, RASSF1A in 32.4% and BLU in 35.3% of tumours. Any two of the gene alterations were associated with each other except RARbeta. DLEC1 methylation was an independent marker of poor survival in the whole cohort (P=0.025) and in squamous cell carcinoma (P=0.041). MLH1 methylation was also prognostic, particularly in large cell cancer (P=0.006). Concordant methylation of DLEC1/MLH1 was the strongest independent indicator of poor prognosis in the whole cohort (P=0.009). However, microsatellite instability and loss of MLH1 expression was rare, suggesting that MLH1 promoter methylation does not usually lead to gene silencing in lung cancer. This is the first study describing the prognostic value of DLEC1 and MLH1 methylation in NSCLC. The concordant methylation is possibly a consequence of a long-range epigenetic effect in this region of chromosome 3p, which has recently been described in other cancers.

Prognostic significance of DNA repair proteins MLH1, MSH2 and MGMT expression in non-small-cell lung cancer and precursor lesions.

AIMS: To investigate the role of DNA repair proteins and their prognostic significance in non-small-cell lung cancer (NSCLC). METHODS AND RESULTS: A retrospective analysis of 108 cases of stage I-II NSCLC was undertaken. Immunohistochemical expression of DNA repair proteins MLH1, MSH2 and MGMT was assessed using tissue microarrays of paraffin-embedded samples of invasive carcinoma and precursor lesions. Results were analysed in relation to clinicopathological parameters and patient survival. Reduced expression of MLH1 was found in 58.5% of tumours and occurred less frequently in poorly differentiated tumours (P = 0.044) and large cell carcinomas (P = 0.004). MSH2 and MGMT expression was reduced in 18.1% and 77.8% of cases, respectively. There was an inverse relationship between MLH1 and MSH2 expression (P = 0.012). Normal expression of MLH1, MSH2 and MGMT was found in all cases of squamous metaplasia and squamous dysplasia. Only a single case of carcinoma in situ (12.5%) showed reduced MLH1, none showed reduced MSH2 and 25% showed reduced MGMT. Survival analyses showed no prognostic significance based on expression of MLH1 (P = 0.92), MSH2 (P = 0.78) or MGMT (P = 0.57). CONCLUSIONS: Reduction in expression of DNA repair proteins MLH1, MSH2 and MGMT is relatively common in NSCLC, appears to be a late event in the development of invasive malignancy and does not influence survival in this patient cohort.

"Rhabdoid meningioma" lacking malignant features. Report of two cases.

We report 2 cases of meningiomas with rhabdoid morphology but lacking histological features of malignancy. Both occurred in adult women, one arising from the superior surface of the tentorium and the other in the Sylvian fissure. The tumors showed light microscopic, immunohistochemical and ultrastructural evidence of meningothelial differentiation together with diffuse or focal areas exhibiting rhabdoid morphology. The rhabdoid areas were characterized by cells with large cytoplasmic eosinophilic inclusions and large eccentric nuclei. Both cases showed areas with sheet-like growth and one had macronucleoli and brain invasion. The same case showed areas of necrosis that most likely related to pre-operative arterial embolization. Unlike most cases reported in the literature, these "rhabdoid meningiomas" lacked significant mitotic activity or other atypical features. The diagnostic and prognostic significance of this tumor entity is discussed along with a review of the literature.

1H NMR visible lipids are induced by phosphonium salts and 5-fluorouracil in human breast cancer cells.

Cationic lipophilic phosphonium salts (CLPS) selectively accumulate in the mitochondria of neoplastic cells and inhibit mitochondrial function. The effects of the CLPS p-(triphenylphosphoniummethyl) benzaldehyde chloride (drug A), and [4-(hydrazinocarboxy)-1-butyl] tris-(4-dimethylaminophenyl) phosphonium chloride (drug B), on human breast cells of differing biological properties were assessed using growth inhibition assays and 1H NMR. Drug A and, to a lesser extent, drug B demonstrated selective growth inhibition of the highly tumorigenic DU4475 breast carcinoma cell line compared to the transformed HBL-100 human breast cell line. However, in contrast to previous studies using other cell lines, no synergistic activity was found when the drugs were used in combination. 1H NMR demonstrated significant increases in mobile lipid acyl chain resonances in both cell lines treated with cytotoxic doses (IC50, 48 h) of the drugs used either alone or in combination. Two-dimensional NMR revealed accompanying decreases in phosphocholine/Lys levels in HBL-100 cells treated with A, B, or a 1:1 combination A+B at the IC50, and in DU4475 cells treated with drug A (IC50). This was accompanied by significant increases in cho/Lys ratios with IC50 A or combination A+B treatment. Similar spectra were observed in cells treated with 5-fluorouracil but not methotrexate, indicating that mobile lipid accumulation is a general but not universal response to cytotoxic insult.

Management of bronchopleural fistula after lobectomy.

Bronchopleural fistula after lobectomy is fortunately a rare complication. In years past, this complication was encountered far more frequently. However, the morbidity associated with this complication is still significant. Bronchopleural fistulas develop in patients who are at increased risk of surgical morbidity because of their concomitant medical problems or as a result of chemotherapy for lung cancer or immunosuppression in transplant patients. These patients often present in a moribund, septic state, making their treatment even more difficult. Nevertheless, evaluation and management of these patients should proceed in a logical stepwise fashion. Evaluation of the patient with a bronchopleural fistula should proceed in a logical, stepwise manner form diagnosis to pulmonary rehabilitation.