Microautophagy of the nucleus coincides with a vacuolar diffusion barrier at nuclear-vacuolar junctions.

Nuclei bind yeast vacuoles via nucleus-vacuole (NV) junctions. Under nutrient restriction, NV junctions invaginate and release vesicles filled with nuclear material into vacuoles, resulting in piecemeal microautophagy of the nucleus (PMN). We show that the electrochemical gradient across the vacuolar membrane promotes invagination of NV junctions. Existing invaginations persist independently of the gradient, but final release of PMN vesicles requires again V-ATPase activity. We find that NV junctions form a diffusion barrier on the vacuolar membrane that excludes V-ATPase but is enriched in the VTC complex and accessible to other membrane-integral proteins. V-ATPase exclusion depends on the NV junction proteins Nvj1p,Vac8p, and the electrochemical gradient. It also depends on factors of lipid metabolism, such as the oxysterol binding protein Osh1p and the enoyl-CoA reductase Tsc13p, which are enriched in NV junctions, and on Lag1p and Fen1p. Our observations suggest that NV junctions form in two separable steps: Nvj1p and Vac8p suffice to establish contact between the two membranes. The electrochemical potential and lipid-modifying enzymes are needed to establish the vacuolar diffusion barrier, invaginate NV junctions, and form PMN vesicles.

Stereotactic body radiation therapy in stage I inoperable lung cancer: from palliative to curative options.

Surgery has historically been the standard of care for operable stage I non-small cell lung cancer (NSCLC). However, nearly one-quarter of patients with stage I NSCLC will not undergo surgery because of medical comorbidity or other factors. Stereotactic ablative radiotherapy (SABR) is the new standard of care for these patients. SABR offers high local tumour control rates rivalling the historical results of surgery and is generally well tolerated by patients with both peripheral and centrally located tumours. This article reviews the history of SABR for stage I NSCLC, summarises the currently available data on efficacy and toxicity, and describes some of the currently controversial aspects of this treatment.

Involvement of nuclear factor-kappaB in macrophage migration inhibitory factor gene transcription up-regulation induced by interleukin- 1 beta in ectopic endometrial cells.

OBJECTIVE: To investigate the involvement of the nuclear factor (NF)-kappaB in the interleukin (IL)-1 beta-mediated macrophage migration inhibitory factor (MIF) gene activation. DESIGN: Prospective study. SETTING: Human reproduction research laboratory. PATIENT(S): Nine women with endometriotic lesions. INTERVENTION(S): Endometriotic lesions were obtained during laparoscopic surgery. MAIN OUTCOME MEASURE(S): The MIF protein secretion was analyzed by ELISA, MIF mRNA expression by quantitative real-time polymerase chain reaction (PCR), NF-kappaB translocation into the nucleus by electrophoresis mobility shift assay, I kappaB phosphorylation and degradation by Western blot, and human MIF promoter activity by transient cell transfection. RESULT(S): This study showed a significant dose-dependent increase of MIF protein secretion and mRNA expression, the NF-kappaB translocation into the nucleus, I kappaB phosphorylation, I kappaB degradation, and human MIF promoter activity in endometriotic stromal cells in response to IL-1 beta. Curcumin (NF-kappaB inhibitor) significantly inhibited all these IL-1 beta-mediated effects. Analysis of the activity of deletion constructs of the human MIF promoter and a computer search localized two putative regulatory elements corresponding to NF-kappaB binding sites at positions -2538/-2528 bp and -1389/-1380 bp. CONCLUSION(S): This study suggests the involvement of the nuclear transcription factor NF-kappaB in MIF gene activation in ectopic endometrial cells in response to IL-1 beta and identifies a possible pathway of endometriosis-associated inflammation and ectopic cell growth.

Phenotypic divergence but not genetic distance predicts assortative mating among species of a cichlid fish radiation.

The hypothesis of ecological divergence giving rise to premating isolation in the face of gene flow is controversial. However, this may be an important mechanism to explain the rapid multiplication of species during adaptive radiation following the colonization of a new environment when geographical barriers to gene flow are largely absent but underutilized niche space is abundant. Using cichlid fish, we tested the prediction of ecological speciation that the strength of premating isolation among species is predicted by phenotypic rather than genetic distance. We conducted mate choice experiments between three closely related, sympatric species of a recent radiation in Lake Mweru (Zambia/DRC) that differ in habitat use and phenotype, and a distantly related population from Lake Bangweulu that resembles one of the species in Lake Mweru. We found significant assortative mating among all closely related, sympatric species that differed phenotypically, but none between the distantly related allopatric populations of more similar phenotype. Phenotypic distance between species was a good predictor of the strength of premating isolation, suggesting that assortative mating can evolve rapidly in association with ecological divergence during adaptive radiation. Our data also reveals that distantly related allopatric populations that have not diverged phenotypically, may hybridize when coming into secondary contact, e.g. upon river capture because of diversion of drainage systems.

Decreased local control following radiation therapy alone in early-stage glottic carcinoma with anterior commissure extension.

PURPOSE: To assess the patterns of failure in the treatment of early-stage squamous cell carcinoma of the glottic larynx. PATIENTS AND METHODS: Between 1983-2000, 122 consecutive patients treated for early laryngeal cancer (UICC T1N0 and T2N0) by radical radiation therapy (RT) were retrospectively studied. Male-to-female ratio was 106 : 16, and median age 62 years (35-92 years). There were 68 patients with T1a, 18 with T1b, and 36 with T2 tumors. Diagnosis was made by biopsy in 104 patients, and by laser vaporization or stripping in 18. Treatment planning consisted of three-dimensional (3-D) conformal RT in 49 (40%) patients including nine patients irradiated using arytenoid protection. A median dose of 70 Gy (60-74 Gy) was given (2 Gy/fraction) over a median period of 46 days (21-79 days). Median follow-up period was 85 months. RESULTS: The 5-year overall, cancer-specific, and disease-free survival amounted to 80%, 94%, and 70%, respectively. 5-year local control was 83%. Median time to local recurrence in 19 patients was 13 months (5-58 months). Salvage treatment consisted of surgery in 17 patients (one patient refused salvage and one was inoperable; total laryngectomy in eleven, and partial laryngectomy or cordectomy in six patients). Six patients died because of laryngeal cancer. Univariate analyses revealed that prognostic factors negatively influencing local control were anterior commissure extension, arytenoid protection, and total RT dose < 66 Gy. Among the factors analyzed, multivariate analysis (Cox model) demonstrated that anterior commissure extension, arytenoid protection, and male gender were the worst independent prognostic factors in terms of local control. CONCLUSION: For early-stage laryngeal cancer, outcome after RT is excellent. In case of anterior commissure extension, surgery or higher RT doses are warranted. Because of a high relapse risk, arytenoid protection should not be attempted.

Second cranio-facial malignancies in hereditary retinoblastoma survivors previously treated with radiation therapy: clinic and radiologic characteristics and survival outcomes.

INTRODUCTION: Hereditary retinoblastoma survivors have an increased risk for cranio-facial second primary tumours (SPT), especially after treatment with external beam radiotherapy (EBRT). This multicentre study evaluates the clinical and imaging characteristics and outcomes of cranio-facial SPTs in irradiated retinoblastoma survivors. PATIENTS AND METHODS: Clinical and radiological data of 42 hereditary retinoblastoma patients with 44 second and third malignancies were reviewed. Radiological data included anatomic location and computed tomography (CT) and magnetic resonance (MR) characteristics. Cox regression and likelihood ratio chi-square test were used to evaluate differences in patients' survival rates. RESULTS: Cranio-facial SPTs were diagnosed at a median age of 13 years. Histological types included osteosarcomas (43%), rhabdomyosarcomas (20%) (57% embryonal, 43% alveolar) and a variety of other types of SPT (37%). Predilection sites were: temporal fossa (39%), ethmoid sinus (23%), orbit (18%), maxillary sinus (16%) and intracranial dura mater (4%). Most of the osteosarcomas (78%) and rhabdomyosarcomas (80%) occurred in patients treated with EBRT in the first year-of-life. Treatment of SPTs with a microscopically complete surgical resection led to a significantly better 5-year overall survival (OS) (P=0.017) and event-free survival (EFS) (P=0.012) compared to patients treated without surgery or incomplete resection (OS: 83% versus 52%; EFS: 80% versus 47%). CONCLUSIONS: Osteosarcomas and rhabdomyosarcomas are the most common cranio-facial SPTs in irradiated hereditary retinoblastoma survivors, which develop in specific locations and occur predominantly in patients irradiated in their first year-of-life. Microscopically complete surgical resection of SPTs is a major prognostic factor, suggesting the potential benefit of early detection by imaging.

Traitement non chirurgical des rectites postactiniques ou radiques chroniques [Non-surgical treatment of acute and late radiation proctitis]

Pelvic external radiotherapy with or without brachytherapy plays an important role in the management of pelvic cancers. Despite recent technical innovations including conformal three-dimensional (3D) external beam radiotherapy and more recently intensity modulated radiotherapy (IMRT), local side effects can occur secondary to normal tissue damage caused by ionising radiation. Morbidity depends on the anatomic position of the rectum within the pelvis and the fast turnover rate of the mucosa, as well as the characteristics of the radiation treatment and patient co-morbidities. Medical management is sometimes complex and merits herein a short review.

The effect of in vitro heating on the distribution of nuclear matrix polypeptides in HeLa cells.

The in situ nuclear matrix was obtained from HeLa cells. After permeabilization with nonionic detergent, the resulting structures were incubated for 1 h at 37 degrees C to determine whether or not such an incubation might result in the redistribution of nuclear polypeptides which resisted extraction with buffers of high-ionic strength (1.6 M NaCl or 0.25 M (NH4)2SO4 as well as DNase I digestion. Using indirect immunofluorescence experiments and monoclonal antibodies we show that heating to 37 degrees C changes the distribution of a 160 kDa protein previously shown to be a component of the inner matrix network. On the other hand, a 125 kDa polypeptide was not affected at all by the incubation. Our results clearly indicate that the inclusion of a 37 degrees C incubation (for example during digestion with DNase I) in the protocol to obtain the in situ nuclear matrix can result in the formation of in vitro artifacts.

Water-filtered infrared-A radiation (wIRA) is not implicated in cellular degeneration of human skin

Rapport de synthèse : Introduction : le vieillissement cutané est un processus biologique complexe auquel participe une exposition excessive au rayonnement ultraviolet du soleil. En particulier, les longueurs d'onde des rayons ultraviolets A et B (UV-A et UV-B) peuvent induire une augmentation de la synthèse de protéases, comme la métalloprotéinase matricielle 1 (MMP-1), qui est impliquée dans le processus de vieillissement. La thermothérapie par infrarouges, dont les longueurs d'onde sont plus longues que celles des UV, est largement utilisée à des fins thérapeutiques ou cosmétiques. Or, il a été démontré que les infrarouges en filtration aqueuse (IRFA) pouvaient induire une augmentation de la production de MMP-1 et par conséquent être nocifs. Il serait donc intéressant d'évaluer les effets des IRFA au niveau cellulaire et moléculaire. But Expérimental : étudier les effets des lampes à infrarouges en filtration aqueuse utilisées en clinique sur des fibroblastes cutanés humains en culture, afin d'analyser l'expression du gène codant pour la protéine MMP-1. Méthode : des fibroblastes cutanés humain ont été irradiés d'une part avec approximativement 88% d'IRFA (780-1400 nm) et 12% de lumière rouge (LR, 665-780 nm) avec 380 mW/cm2 IRFA(+LR) (333 mW/cm2 IRFA) et d'autre part avec des UV-A comme contrôle. Des courbes de survie cellulaire ont été établies après une exposition allant de 15 minutes à 8 heures au IRFA(+LR) (340-10880 J/cm2 wIRA(+RL), 300-9600 J/cm2 wIRA) ou de 15 à 45 minutes aux UV-A(+BL) (25-75 J/cm2 UV-A(+BL). L'induction de l'ARNm du gène de la MMP-1 a été analysé dans les fibroblastes cutanés humain à deux températures physiologiques (30°C et 37°C) lors d'expositions uniques de 15 à 60 minutes aux IRFA(+LR) (340-1360 J/cm2 IRFA(+LR), 300-1200 J/cm2 IRFA) ou de 30 minutes aux UV-A(+BL) (50 J/cm2 UVA(+BL)). De plus, nous avons effectué des irradiations répétées, une a chaque passage cellulaire jusqu'au passage. 10 de 15 minutes d'IRFA(+LR) 340 J/cm2 IRFA(+LR), 300 J/cm2 IRFA) . Résultats : une exposition unique aux UV-A (+BL) entraîne chez des fibroblastes cutanés humains une augmentation de la mort cellulaire, ainsi qu'une forte augmentation de l'expression du gène codant pour la MMP-1. L'augmentation mise en évidence pour cet ARNm varie en fonction de la technique utilisée : elle est de 11 ± 1 fois par RT-PCR classique, de 76 ± 2 fois par RT-PCR quantitative à 30°C, et de 75 ± 1 fois par RT-PCR quantitative à 37°C. Par contre, une exposition unique ou répétée aux IRFA (+LR) n'induit aucune augmentation de la mort cellulaire, ni de l'expression de l'ARNm de la MMP-1 chez ces fibroblastes. Conclusions : les résultats de cette étude montrent que, contrairement aux rayons ultraviolets, les IRFA (+LR) ne semblent impliqués ni dans le vieillissement, ni dans la mort cellulaire, même utilisés à des doses très élevées. Ces résultats sont en accord avec certaines investigations in vivo montrant une induction de MMP-1 par des UV et non des infrarouges. Ces dernières études suggèrent d'ailleurs plutôt un rôle protecteur des IRFA (+LR).

Evaluation of organ-specific peripheral doses after 2-dimensional, 3-dimensional and hybrid intensity modulated radiation therapy for breast cancer based on Monte Carlo and convolution/superposition algorithms: implications for secondary cancer risk assessment.

To make a comprehensive evaluation of organ-specific out-of-field doses using Monte Carlo (MC) simulations for different breast cancer irradiation techniques and to compare results with a commercial treatment planning system (TPS). Three breast radiotherapy techniques using 6MV tangential photon beams were compared: (a) 2DRT (open rectangular fields), (b) 3DCRT (conformal wedged fields), and (c) hybrid IMRT (open conformal+modulated fields). Over 35 organs were contoured in a whole-body CT scan and organ-specific dose distributions were determined with MC and the TPS. Large differences in out-of-field doses were observed between MC and TPS calculations, even for organs close to the target volume such as the heart, the lungs and the contralateral breast (up to 70% difference). MC simulations showed that a large fraction of the out-of-field dose comes from the out-of-field head scatter fluence (>40%) which is not adequately modeled by the TPS. Based on MC simulations, the 3DCRT technique using external wedges yielded significantly higher doses (up to a factor 4-5 in the pelvis) than the 2DRT and the hybrid IMRT techniques which yielded similar out-of-field doses. In sharp contrast to popular belief, the IMRT technique investigated here does not increase the out-of-field dose compared to conventional techniques and may offer the most optimal plan. The 3DCRT technique with external wedges yields the largest out-of-field doses. For accurate out-of-field dose assessment, a commercial TPS should not be used, even for organs near the target volume (contralateral breast, lungs, heart).

Involvement of PPAR nuclear receptors in tissue injury and wound repair.

Tissue damage resulting from chemical, mechanical, and biological injury, or from interrupted blood flow and reperfusion, is often life threatening. The subsequent tissue response involves an intricate series of events including inflammation, oxidative stress, immune cell recruitment, and cell survival, proliferation, migration, and differentiation. In addition, fibrotic repair characterized by myofibroblast transdifferentiation and the deposition of ECM proteins is activated. Failure to initiate, maintain, or stop this repair program has dramatic consequences, such as cell death and associated tissue necrosis or carcinogenesis. In this sense, inflammation and oxidative stress, which are beneficial defense processes, can become harmful if they do not resolve in time. This repair program is largely based on rapid and specific changes in gene expression controlled by transcription factors that sense injury. PPARs are such factors and are activated by lipid mediators produced after wounding. Here we highlight advances in our understanding of PPAR action during tissue repair and discuss the potential for these nuclear receptors as therapeutic targets for tissue injury.

A New Twist on Radiation Oncology: Low-Dose Irradiation Elicits Immunostimulatory Macrophages that Unlock Barriers to Tumor Immunotherapy.

Tumor-infiltrating macrophages typically promote angiogenesis while suppressing antitumoral T cell responses. In this issue of Cancer Cell, Klug and colleagues report that clinically-feasible, low-dose irradiation redirects macrophage differentiation from a tumor-promoting/immunosuppressive state to one that enables cytotoxic T cells to infiltrate tumors and kill cancer cells, rendering immunotherapy successful in mice.

Protection from radiation-induced colitis requires MHC class II antigen expression by cells of hemopoietic origin.

Ulcerative colitis, an inflammatory bowel disease, is believed to result from a breakdown of dominant tolerance mechanisms that normally control intestinal immunity. Although CD4+ T lymphocyte subpopulations and expression of MHC class II molecules have been shown to play a role in the pathogenesis of the disease, the nature of the responsible mechanisms remains unclear. In this paper we describe a novel mouse model for inflammatory bowel disease, radiation-induced colitis, that occurs with complete penetrance 6-8 wk postinduction. A combination of high dose gamma-irradiation and lack of MHC class II expression on cells of hemopoietic origin results in development of colitis in C57BL/6 mice. Because of its versatility (due to susceptibility of mice of the widely genetically manipulated C57BL/6 background), high reproducibility, and 100% penetrance, radiation-induced colitis will be a useful mouse model for colitis and a significant tool to study dominant immunological tolerance mechanisms. Moreover, our data imply that tolerization to enteric Ags requires MHC class II mediated presentation by APC of hemopoietic origin.