Inhibition of WNT signaling attenuates self-renewal of SHH-subgroup medulloblastoma

The SMOOTHENED inhibitor vismodegib is FDA approved for advanced basal cell carcinoma (BCC), and shows promise in clinical trials for SONIC HEDGEHOG (SHH)-subgroup medulloblastoma (MB) patients. Clinical experience with BCC patients shows that continuous exposure to vismodegib is necessary to prevent tumor recurrence, suggesting the existence of a vismodegib-resistant reservoir of tumor-propagating cells. We isolated such tumor-propagating cells from a mouse model of SHH-subgroup MB and grew them as sphere cultures. These cultures were enriched for the MB progenitor marker SOX2 and formed tumors in vivo. Moreover, while their ability to self-renew was resistant to SHH inhibitors, as has been previously suggested, this self-renewal was instead WNT-dependent. We show here that loss of Trp53 activates canonical WNT signaling in these SOX2-enriched cultures. Importantly, a small molecule WNT inhibitor was able to reduce the propagation and growth of SHH-subgroup MB in vivo, in an on-target manner, leading to increased survival. Our results imply that the tumor-propagating cells driving the growth of bulk SHH-dependent MB are themselves WNT dependent. Further, our data suggest combination therapy with WNT and SHH inhibitors as a therapeutic strategy in patients with SHH-subgroup MB, in order to decrease the tumor recurrence commonly observed in patients treated with vismodegib.

Multicenter Phase II Study of Panitumumab in Platinum Pretreated, Advanced Head and Neck Squamous Cell Cancer

Lessons Learned.

Panitumumab shows activity in terms of disease control rate and preventing disease progression but not for tumor shrinkage in head and neck squamous cell cancer for second‐line treatment. Epidermal growth factor receptor (EGFR) copy number gain, a property of tumor cells that theoretically could identify patients more likely to experience disease response, was common among patients having disease control.

Our trial, given the lower toxicity with an every‐2‐week schedule, provides guidance for future trials, for example, in combinations of immune therapies and anti‐EGFR‐antibodies.

Background.

The objective of this study was to investigate the efficacy and safety of panitumumab (anti‐epidermal growth factor receptor [EGFR] antibody) given as a single agent in platinum‐pretreated head and neck squamous cell cancer (HNSCC).

Methods.

Patients with advanced HNSCC previously treated with platinum‐containing therapy were included. Panitumumab was administered intravenously every 2 weeks at a dose of 6 mg/kg. Primary endpoint was overall response rate (ORR) according to Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1; secondary endpoints were progression‐free survival (PFS) and safety. A Simon's two‐step design was chosen; 4 partial remissions (PR) in the first 32 patients were required for continuing to step two. An exploratory biomarker analysis was performed.

Results.

Thirty‐three patients were enrolled. Two patients obtained a PR for an ORR of 6%, and 15 (45%) showed stable disease (SD) for at least 2 months, resulting in a 51% disease control rate. Median PFS was 2.6 months (95% confidence interval [CI]: 1.7–3.7), while median OS was 9.7 months (95% CI: 6.3–17.2). The most frequent adverse drug reactions were cutaneous rash (64%) and hypomagnesemia (55%). Overall, 30% of patients experienced grade 3/4 adverse events. No infusion‐related reactions occurred. EGFR copy number gain (CNG) was more frequent in patients who benefitted from panitumumab. Two uncommon KRAS mutations (G48E, T50I) and 3 canonical PIK3CA mutations (all E545K) were detected. High‐risk HPV16 was found in 10 patients and EGFR CNG in 13 treated patients. EGFR CNG seems to be more frequent in individuals with at least SD compared with patients with progressive disease (59% vs. 30%). PFS for patients with EGFR CNG was 4.6 months (95% CI: 1.0–9.2 months) and 1.9 months (95% CI: 1.0–3.2 months) for patients without CNG (p = .02).

Conclusion.

Panitumumab monotherapy in pretreated HNSCC patients was well tolerated but moderately active. We observed a considerable disease control rate. Future strategies with this agent comprise right patient selection through the identification of reliable biomarkers and gene signatures predicting response and, considering good tolerability and convenience, combination strategies with novel agents and immune therapeutic agents.

[Estimation of the population attributable fraction due to obesity in hospital admissions for flu valued according to Body Mass Index (BMI) and CUN-BAE]

INTRODUCTION

The obesity pandemic together with the influenza pandemic could lead to a significant burden of disease. The body mass index (BMI) does not discriminate obesity appropriately. The CUN-BAE has recently been used as an estimate of body fatness for Caucasians, including BMI, gender, and age. The aim of this study is to assess the population attributable fraction of hospital admissions due to influenza, due to the body fatness measured with the BMI, and the CUN-BAE.

METHODS

A multicentre study was conducted using matched case-controls. Cases were hospital admissions with the influenza confirmed by the RT-PCR method between 2009 and 2011. The risk of hospital admission and the population attribuible fraction were calculated using the BMI or the CUN-BAE for each adiposity category in a conditional logical regression analysis adjusted for confounding variables. The analyzes were estimated in the total sample, in unvaccinated people, and those less than 65 years-old.

RESULTS

A total of 472 hospitalised cases and 493 controls were included in the study. Compared to normal weight, the aOR of influenza hospital admissions increases with each level of BMI (aOR=1.26; 2.06 and 11.64) and CUN-BAE (aOR=2.78; 4.29; 5.43 and 15.18). The population attributable fraction of influenza admissions using CUN-BAE is 3 times higher than that estimated with BMI (0,72 vs. 0,27), with the differences found being similar the non-vaccinated and under 65 year-olds.

CONCLUSION

The BMI could be underestimating the burden of disease attributable to obesity in individuals hospitalised with influenza. There needs to be an appropriate assessment of the impact of obesity and vaccine recommendation criteria.

Synovial sarcoma metastatic to the parotid gland: A possible pitfall in salivary gland fine needle aspiration cytology. Report of a case with immunocytochemical and fluorescence in situ hybridization findings

We report one case of metastatic synovial sarcoma (SS) to the parotid gland in a 93-year-old male. The patient had undergone upper left pulmonary lobectomy with mediastinal lymphadenectomy for SS of the lung 5 years before. The cytopathologic presentation and the immunocytochemical findings on the FNA sample were suggestive of a spindle cell myoepithelioma, while a SYT rearrangement was identified by a FISH performed on a cytological smear of the lesion. The diagnosis was further confirmed also by positive immunocytochemical expression of TLE1 on a section from the obtained cell block. The cytologic and immunophenotypic findings are shortly discussed in view of the reported immunophenotypic inconsistency of SS and of its differential diagnosis with spindle cell myoepithelioma of the salivary glands.The importance of the recently described TLE1 staining and its close correlation to SYT rearrangement is briefly discussed.

Soluble Milk Proteins Improve Muscle Mass Recovery after Immobilization-Induced Muscle Atrophy in Old Rats but Do not Improve Muscle Functional Property Restoration

OBJECTIVES

Effect of 3 different dairy protein sources on the recovery of muscle function after limb immobilization in old rats.

DESIGN

Longitudinal animal study.

SETTING

Institut National de la Recherche Agronomique (INRA). The study took part in a laboratory setting.

INTERVENTION

Old rats were subjected to unilateral hindlimb immobilization for 8 days and then allowed to recover with 3 different dietary proteins: casein, soluble milk proteins or whey proteins for 49 days.

MEASUREMENTS

Body weight, muscle mass, muscle fibre size, isometric, isokinetic torque, muscle fatigability and muscle oxidative status were measured before and at the end of the immobilization period and during the recovery period i.e 7, 21, 35 and 49 days post immobilization.

RESULTS

In contrast to the casein diet, soluble milk proteins and whey proteins were efficient to favor muscle mass recovery after cast immobilization during aging. By contrast, none of the 3 diary proteins was able to improve muscle strength, power and fatigability showing a discrepancy between the recovery of muscle mass and function. However, the soluble milk proteins allowed a better oxidative capacity in skeletal muscle during the rehabilitation period.

CONCLUSION

Whey proteins and soluble milk proteins improve muscle mass recovery after immobilization-induced muscle atrophy in old rats but do not allow muscle functional property restoration.

Brain plasticity and cognitive functions after ethanol consumption in C57BL/6J mice

Acute or chronic administrations of high doses of ethanol in mice are known to produce severe cognitive deficits linked to hippocampal damage. However, we recently reported that chronic and moderate ethanol intake in C57BL/6J mice induced chromatin remodeling within the Bdnf promoters, leading to both enhanced brain-derived neurotrophic factor (BDNF) expression and hippocampal neurogenesis under free-choice protocol. We performed here a series of cellular and behavioral studies to analyze the consequences of these modifications. We showed that a 3-week chronic free-choice ethanol consumption in C57BL/6J mice led to a decrease in DNA methylation of the Bdnf gene within the CA1 and CA3 subfields of the hippocampus, and upregulated hippocampal BDNF signaling pathways mediated by ERK, AKT and CREB. However, this activation did not affect long-term potentiation in the CA1. Conversely, ethanol intake impaired learning and memory capacities analyzed in the contextual fear conditioning test and the novel object recognition task. In addition, ethanol increased behavioral perseveration in the Barnes maze test but did not alter the mouse overall spatial capacities. These data suggested that in conditions of chronic and moderate ethanol intake, the chromatin remodeling leading to BDNF signaling upregulation is probably an adaptive process, engaged via epigenetic regulations, to counteract the cognitive deficits induced by ethanol.

EGFR and KRAS Mutations in ALK-Positive Lung Adenocarcinomas: Biological and Clinical Effect

INTRODUCTION

In lung adenocarcinoma (ADC), anaplastic lymphoma receptor tyrosine kinase (ALK) rearrangements are mutually exclusive with epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations. However, the existence of double-positive (DP) patients have been sporadically described. We identified DP cases in therapy-naive ALK-rearranged ADC and characterized the biology of these tumors to better understand the clinical response to tyrosine kinase inhibitors (TKIs).

MATERIALS AND METHODS

We selected 42 ALK-positive ADCs from a multicentric series of 301 cases of ADCs. A mutational analysis was performed using Sanger and/or pyrosequencing to address exons 18-21 of EGFR and codons 12-13 of the KRAS gene. In addition, the KRAS and EGFR copy number was investigated using fluorescent in situ hybridization. DP patients were treated with TKIs, and their response was evaluated according to the Response Evaluation Criteria in Solid Tumors criteria.

RESULTS

Eight of 42 ALK-positive ADCs (19%) demonstrated a concomitant mutation in the EGFR (3 cases) or KRAS (5 cases) genes and were classified as DP. All DP cases displayed copy number gains in the EGFR or KRAS gene because of polysomy or gene amplification. In the latter cases, a mutant allele-specific imbalance was observed. Four patients were treated with TKIs. The 2 EGFR-mutant DP patients demonstrated a better response to crizotinib compared with erlotinib. The 2 KRAS-mutant DP patients experienced opposite responses to crizotinib.

CONCLUSION

The incidence of DP ADC is not negligible. Patients with ALK/EGFR might benefit more from crizotinib compared with erlotinib administration, although the efficacy of TKIs in patients with ALK/KRAS remains unclear. An integrated targeted therapy should be considered for patients with DP ADC.

HER2 in solid tumors: more than 10 years under the microscope; where are we now?

HER2 is a well-recognized mediator of the cancerogenic process. It is dysregulated in a wide range of solid tumors, mainly via protein overexpression and/or gene amplification, thus making HER2 an attractive target for tailored treatment. The anti-HER2 therapy trastuzumab was approved for the treatment of HER2-positive metastatic breast cancer patients more than 10 years ago. Since then, trastuzumab and other HER2-inhibitors have been entered into clinical practice for the treatment of breast cancer and, more recently, have been approved to treat HER2-positive metastatic gastric cancers. Currently, HER2-targeted therapies are under evaluation in other tumor types. Due to the relevance of proper patient selection, the accurate assessment of HER2 status is fundamental. This review will discuss the established knowledge and novel insights into the HER2 story, mainly focusing on breast, gastric and colorectal cancers, as well as providing a brief overview of salivary gland, bladder, ovarian and lung tumors.

Improved tolerance of peripheral fatigue by the central nervous system after endurance training

PURPOSE

The purposes of this study were to evaluate the effect of endurance training on central fatigue development and recovery.

METHODS

A control group was compared to a training group, which followed an 8-week endurance-training program, consisting in low-force concentric and isometric contractions. Before (PRE) and after (POST) the training period, neuromuscular function of the knee extensor (KE) muscles was evaluated before, immediately after and during 33 min after an exhausting submaximal isometric task at 15 % of the maximal voluntary contraction (MVC) force. After training, the trained group performed another test at iso-time, i.e., with the task maintained until the duration completed before training was matched (POST2). The evaluation of neuromuscular function consisted in the determination of the voluntary activation level during MVCs, from peripheral nerve electrical (VAPNS) and transcranial magnetic stimulations (VATMS). The amplitude of the potentiated twitch (Pt), the evoked [motor evoked potentials, cortical silent period (CSP)] and voluntary EMG activities were also recorded on the KE muscles.

RESULTS

Before training, the isometric task induced significant reductions of VAPNS, VATMS and Pt, and an increased CSP. The training period induced a threefold increase of exercise duration, delayed central fatigue appearance, as illustrated by the absence of modification of VAPNS, VATMS and CSP after POST2. At POST, central fatigue magnitude and recovery were not modified but Pt reduction was greater.

CONCLUSION

These results suggest that central fatigue partially adapts to endurance training. This adaptation principally translates into improved tolerance of peripheral fatigue by the central nervous system.

Laccase wiring on free-standing electrospun carbon nanofibres using a mediator plug

The enzyme laccase was wired on a free-standing electrospun carbon fiber mat using a cross-linker plug based on the pyrene modified electron shuttle ABTS.

Screening for the FIG-ROS1 fusion in biliary tract carcinomas by nested PCR

ROS1 rearrangements have been detected in a variety of tumors and are considered as suitable targets of anticancer therapies. We developed a new, quick, specific, and sensitive PCR test to screen for the FIG-ROS1 fusion and applied it to a series of Italian patients with bile duct carcinoma (BTC). Formalin-fixed, paraffin-embedded tissues, derived from 65 Italian BTC patients, and six cell lines were analyzed by nested PCR to investigate the prevalence of a previously reported FIG-ROS1 fusion. The specificity and sensitivity of nested PCR were investigated in FIG-ROS1 positive U118MG cells in reconstitution experiments with peripheral blood mononuclear cells. We found that six out of 65 (9%) BTC patients were positive for the FIG-ROS1 fusion, comprising two out of 14 (14%) gallbladder carcinoma (GBC) patients and four out of 25 (16%) extrahepatic cholangiocarcinoma (ECC) patients. None of the 26 intrahepatic cholangiocarcinoma cases harbored the FIG-ROS1 fusion. All the cell lines were negative for this variant. In conclusion, 14-16% of GBC and ECC were positive for FIG-ROS1. This may have clinical implications, since these patients will potentially benefit from the treatment with specific ROS1 inhibitors.

[Pulsed-dose rate brachytherapy in cervical cancers: why, how?]

The end of the production of 192 iridium wires terminates low dose rate brachytherapy and requires to move towards pulsed-dose rate or high-dose rate brachytherapy. In the case of gynecological cancers, technical alternatives exist, and many teams have already taken the step of pulsed-dose rate for scientific reasons. Using a projector source is indeed a prerequisite for 3D brachytherapy, which gradually installs as a standard treatment in the treatment of cervical cancers. For other centers, this change implies beyond investments in equipment and training, organizational consequences to ensure quality.

Chromosomal aberrations of cancer-testis antigens in myeloma patients

Cancer-testis antigens (CTAgs) play a major role in the immune response against cancer, but their biological functions in germ and cancer cells is still unclear. MAGE-C1 and MAGE-C2 are two CTAgs located at the Xq27 region of chromosome X and frequently expressed in multiple myeloma. Chromosomal rearrangements often occur in myeloma. We therefore investigated whether numerical and structural chromosomal aberrations correlate with their protein expression in primary multiple myelomas. To this aim, we designed new fluorescence in situ hybridization probes specific for the MAGE region in the Xq27 region and evaluated simultaneously aberrations of the X chromosome centromere. The comparison of MAGE copy number and chromosome X status revealed that MAGE copy number changes occurred in 6/43 (14%) cases, independent of concomitant X chromosome alterations. These numerical aberrations are less frequent than the expression of MAGE-C1 and MAGE-C2 (63% and 27% of patients, respectively) and do not always correlate with MAGE-C1 and MAGE-C2 expressions, suggesting alternative regulatory mechanisms in the expression of these genes.