IDH1/IDH2 mutations predict survival in glioma and AML

Mutations in the isocitrate dehydrogenase family genes 1 or 2 (IDH1/2) have been discovered by high through put sequencing approaches inglioma and acute myeloid leukemia (AML) and related myeloproliferativeneoplasms. In both diseases, the discovery of IDH mutations has identifieda prognostically new subtype with distinct pathogenetic evolution. Ingliomas mutations are mostly found in IDH1 (>90%). They are infrequent inprimary glioblastoma (GBM) (<10%), but common in secondary GBM thatevolve from lower grade glioma (60−90%). Mutations in IDH1 precede p53mutations or 1p/19q co-deletions in sporadic low grade glioma, hence arean early evant. Co-deletions of 1p/19q, characteristic for oligodenroglioma,are highly associated with IDH1/2 mutations, while they are mutuallyexclusive with EGFR amplifications, a hall mark of primary GBM. IDH1 or 2mutations are associated with younger patient age, but absent in childhoodgliomas, and have a better prognosis that seems to be consistent in gradeII through IV gliomas. In myeloid malignancies mutations are more likelyin IDH2 and are found in de novo and secondary AML (12−18%) andpre-leukemic clonal malignancies (5% chronic; 20% transformed). IDH1/2mutations are strongly associated with NPM1 mutations that are found in30% of novo cytogenetically normal AML. In CN-AML with mutated NPM1,without FLT3 internal tandem duplication (ITD) IDH mutations constitutean adverse prognostic factor. Mutations in the metabolic enzymes IDH1 or2 result in a neomorphic reaction, generating high levels of the metabolite2-hydroxyglutarate (2-HG). IDH mutations are mutually exclusive with TET2mutations in myeloid malignancies that led to the discovery that high levelsof 2-HG inhibit the a-KG dependent dioxygenase TET2. TET2 is involved inepigenetic regulation and mediates demethylation of DNA. This mechanismis in accordance with the association of a methylator phenotype with loss offunction of TET2 by mutation or indirectly by mutation of IDH1/2 in myeloidmalignancies and gliomas, respectively.Metabolism meets Epigenetics. These discoveries will have importantclinical implications: IDH1/2 mutants may serve as unique targets fortherapy. Further, the high concentrations of the onco-metabolite 2-HGgenerated by IDH1/2 mutants, may serve as biomarker in the serum ofpatients with myeloid malignancies and may be amenable by magneticresonance spectroscopy in glioma patients.

Pilot study of induction chemotherapy followed by concomitant chemotherapy and IMRT or tomotherapy for nasopharyngeal carcinoma

Objective: Standard treatment of locally advanced (stages III and IV A-B) nasopharyngeal carcinoma (NPC) consists in chemoradiotherapy with 5-y survival rates of around 60%. However, acute toxicity prevents the administration of adequate adjuvant chemotherapy in nearly half of the patients. This situation has led to the hypothesis that induction chemotherapy followed by chemoradiotherapy may be a superior approach. Many ongoing studies are testing the role of induction chemotherapy in this setting. Newer radiotherapy techniques are becoming available (intensity modulated radiotherapy [IMRT] and tomotherapy). They can achieve a higher degree of accuracy in conforming the radiation to the planned target volume while sparing normal tissue resulting in less acute and long-term toxicity. Methods: We report here our local experience of 11 consecutive locally advanced NPC patients treated between June 2004 and October 2007. Median age was 46 years (range, 17-65). All but one were male patients. Initial stage was stage III in 5, and stage IVA-B in 6 patients. Treatment consisted of 3 cycles of induction TCF (Docetaxel 75 mg/m2- Cisplatin 75 mg/m2- 5-fluorouracil 750 mg/m2/d 5 days) chemotherapy followed by concomitant chemoradiotherapy with 3 cycles of cisplatin (100 mg/m2), or carboplatin (AUC 5) in case of renal impairment. Radiotherapy was delivered by either IMRT or tomotherapy. Macroscopic disease (tumor + involved lymph nodes) was treated with 70 Gy, 2 Gy/fraction (IMRT), or 69.6 Gy, 1.12 Gy/fraction (simultaneus integrated boost [SIB] technique). Elective nodal irradiation of 46-54 Gy lymph was performed in all patients, whereas elective irradiation of the entire nasopharynx (60 Gy) half of patients. Results: All but one tumor were EBV positive. Induction chemotherapy was done as planned for 8 patients (73%). Two patients had only 2 cycles, 1 patient had only1 cycle of TCF, and the other without docetaxel. Concomitant chemotherapy was given as planned in 7 patients (64%). Four patients had only 2 cycles. Radiotherapy could be delivered as planned in all patients. Eight weeks post treatment all patients proved to have a CR (CR or uCR). After a median follow-up of 11 months (range, 6-38 months) only one patient has relapsed. Details on acute and 1 year toxicities will be presented. Conclusion: Treatment of locally advancedNPC with induction and concomitant chemotherapy is feasible and well tolerated. The use of IMRT or tomotherapy technique seems to ameliorate the therapeutic index particularly in regard with xerostomia. All our patients presented a complete response. For the assessment of survival and long-term toxicity, a longer follow-up period is needed.

Importance of influx and efflux systems and xenobiotic metabolizing enzymes in intratumoral disposition of anticancer agents.

In this review, intratumoral drug disposition will be integrated into the wide range of resistance mechanisms to anticancer agents with particular emphasis on targeted protein kinase inhibitors. Six rules will be established: 1. There is a high variability of extracellular/intracellular drug level ratios; 2. There are three main systems involved in intratumoral drug disposition that are composed of SLC, ABC and XME enzymes; 3. There is a synergistic interplay between these three systems; 4. In cancer subclones, there is a strong genomic instability that leads to a highly variable expression of SLC, ABC or XME enzymes; 5. Tumor-expressed metabolizing enzymes play a role in tumor-specific ADME and cell survival and 6. These three systems are involved in the appearance of resistance (transient event) or in the resistance itself. In addition, this article will investigate whether the overexpression of some ABC and XME systems in cancer cells is just a random consequence of DNA/chromosomal instability, hypo- or hypermethylation and microRNA deregulation, or a more organized modification induced by transposable elements. Experiments will also have to establish if these tumor-expressed enzymes participate in cell metabolism or in tumor-specific ADME or if they are only markers of clonal evolution and genomic deregulation. Eventually, the review will underline that the fate of anticancer agents in cancer cells should be more thoroughly investigated from drug discovery to clinical studies. Indeed, inhibition of tumor expressed metabolizing enzymes could strongly increase drug disposition, specifically in the target cells resulting in more efficient therapies.

RTOG 0525: Exploratory Subset Analysis from a Randomized Phase III Trial Comparing Standard (std) Adjuvant Temozolomide (TMZ) with a Dose-dense (dd) Schedule for Glioblastoma (GBM)

Purpose/Objective(s): RTwith TMZ is the standard for GBM. dd TMZ causes prolongedMGMTdepletion in mononuclear cells and possibly in tumor. The RTOG 0525 trial (ASCO 2011) did not show an advantage from dd TMZ for survival or progression free survival. We conducted exploratory, hypothesis-generating subset analyses to detect possible benefit from dd TMZ.Materials/Methods: Patients were randomized to std (150-200 mg/m2 x 5 d) or dd TMZ (75-100 mg/m2 x 21 d) q 4 weeks for 6- 12 cycles. Eligibility included age.18, KPS$ 60, and. 1 cm2 tissue for prospective MGMTanalysis for stratification. Furtheranalyses were performed for all randomized patients (''intent-to-treat'', ITT), and for all patients starting protocol therapy (SPT). Subset analyses were performed by RPA class (III, IV, V), KPS (90-100, = 50,\50), resection (partial, total), gender (female, male), and neurologic dysfunction (nf = none, minor, moderate).Results: No significant difference was seen for median OS (16.6 vs. 14.9 months), or PFS (5.5 vs. 6.7 months, p = 0.06). MGMT methylation was linked to improved OS (21.2 vs. 14 months, p\0.0001), and PFS (8.7 vs. 5.7 months, p\0.0001). For the ITT (n = 833), there was no OS benefit from dd TMZ in any subset. Two subsets showed a PFS benefit for dd TMZ: RPA class III (6.2 vs. 12.6 months, HR 0.69, p = 0.03) and nf = minor (HR 0.77, p = 0.01). For RPA III, dd dramatically delayed progression, but post-progression dd patients died more quickly than std. A similar pattern for nf = minor was observed. For the SPT group (n = 714) there was neither PFS nor OS benefit for dd TMZ, overall. For RPA class III and nf = minor, there was a PFS benefit for dd TMZ (HR 0.73, p = 0.08; HR 0.77, p = 0.02). For nf = moderate subset, both ITT and SPT, the std arm showed superior OS (14.4 vs. 10.9 months) compared to dd, without improved PFS (HR 1.46, p = 0.03; and HR 1.74, p = 0.01. In terms of methylation status within this subset, there were more methylated patients in the std arm of the ITT subset (n = 159; 32 vs. 24%). For the SPT subset (n = 124), methylation status was similar between arms.Conclusions: This study did not demonstrate improved OS for dd TMZ for any subgroup, but for 2 highly functional subgroups, PFS was significantly increased. These data generate the testable hypothesis that intensive treatment may selectively improve disease control in those most likely able to tolerate dd therapy. Interpretation of this should be considered carefully due to small sample size, the process of multiple observations, and other confounders.Acknowledgment: This project was supported by RTOG grant U10 CA21661, and CCOP grant U10 CA37422 from the National Cancer Institute (NCI).

Cholinergic neurons of fetal rat telencephalon in aggregating cell culture respond to NGF as well as to protein kinase C-activating tumor promoters.

Serum-free aggregating cell cultures of fetal rat telencephalon treated with the potent tumor promoter phorbol 12-myristate 13-acetate (PMA) showed a dose-dependent, persistent stimulation of the enzymes choline acetyltransferase (ChAT), glutamic acid decarboxylase and glutamine synthetase. After elimination of the proliferating cells by treatment of the cultures with Ara-C (0.4 microM) only the cholinergic marker enzyme, ChAT, could be stimulated by tumor promoters. The non-promoting phorbol ester, 4 alpha-phorbol 12,13-didecanoate proved to be inactive in these cultures, whereas the potent non-phorbol tumor promoter, mezerein, produced an even greater stimulatory effect than PMA. Since PMA and mezerein are potent and specific activators of protein kinase C, the present results suggest a role for this second messenger in the development of cholinergic telencephalon neurons. Stimulation of ChAT required prolonged exposure (48 h) of the cultures to PMA and the responsiveness of the cholinergic neurons to the tumor promoters decreased with progressive cellular maturation. The cholinergic telencephalon neurons showed the same pattern of responsiveness for tumor promoters as for nerve growth factor (NGF). However, the combined treatment with NGF and either PMA or mezerein produced an additive stimulatory effect, suggesting somewhat different mechanisms of action.

Promising survival for patients with newly diagnosed glioblastoma multiforme treated with concomitant radiation plus temozolomide followed by adjuvant temozolomide.

PURPOSE: Temozolomide is a novel oral alkylating agent with demonstrated efficacy as second-line therapy for patients with recurrent anaplastic astrocytoma and glioblastoma multiforme (GBM). This phase II study was performed to determine the safety, tolerability, and efficacy of concomitant radiation plus temozolomide therapy followed by adjuvant temozolomide therapy in patients with newly diagnosed GBM. PATIENTS AND METHODS: Sixty-four patients were enrolled onto this open-label, phase II trial. Temozolomide (75 mg/m(2)/d x 7 d/wk for 6 weeks) was administered orally concomitant with fractionated radiotherapy (60 Gy total dose: 2 Gy x 5 d/wk for 6 weeks) followed by temozolomide monotherapy (200 mg/m(2)/d x 5 days, every 28 days for six cycles). The primary end points were safety and tolerability, and the secondary end point was overall survival. RESULTS: Concomitant radiation plus temozolomide therapy was safe and well tolerated. Nonhematologic toxicities were rare and mild to moderate in severity. During the concomitant treatment phase, grade 3 or 4 neutropenia, thrombocytopenia, or both were observed in 6% of patients, including two severe infections with Pneumocystis carinii. During adjuvant temozolomide, 2% and 6% of cycles were associated with grade 3 and 4 neutropenia or thrombocytopenia, respectively. Median survival was 16 months, and the 1- and 2-year survival rates were 58% and 31%, respectively. Patients younger than 50 years old and patients who underwent debulking surgery had the best survival outcome. CONCLUSION: Continuous daily temozolomide and concomitant radiation is safe. This regimen of concomitant chemoradiotherapy followed by adjuvant chemotherapy may prolong the survival of patients with glioblastoma. Further investigation is warranted, and a randomized trial is ongoing.

Survival and Molting Incidence after Heat and Cold Shocks in Panstrongylus megistus Burmeister

Survival and molting incidence were studied after heat (40°C) and cold (0°C) shocks in specimens of Panstrongylus megistus with the aim of establishing its response to temperature stress under laboratory rearing conditions and to understand occasional changes in the biological characteristics of specimens captured in nature. The response to the thermal shocks was found to vary as a function of the temperature and duration of the shock, developmental phase and sex of the specimens, and in certain cases, the insect habit and nourishment conditions. P. megistus specimens were found to be less resistant to the heat shock assay than Triatoma infestans, another reduviid species. The short cold shock affected survival of P. megistus more than did the heat shock, survival of fully-nourished specimens being preferential. The response of adults to the short cold shock was affected by sex, males being generally less resistant. The insect sylvatic habit was found to seldom affect the thermal shock response established for specimens with domestic habit. A decrease in molting frequency and sometimes a slowdown of the molting rate were found after the short heat and cold shocks, possibly promoted by change in hormonal balance, and differing from patterns reported for T. infestans. The results indicate that no generalization should be made for different reduviid species in terms of the effects of temperature shocks.

Photodynamic induced uptake of liposomal doxorubicin to rat lung tumors parallels tumor vascular density.

BACKGROUND: Visudyne®-mediated photodynamic therapy (PDT) at low drug/light conditions has shown to selectively enhance the uptake of liposomal doxorubicin in subpleural localized sarcoma tumors grown on rodent lungs without causing morphological alterations of the lung. The present experiments explore the impact of low-dose PDT on liposomal doxorubicin (Liporubicin™) uptake to different tumor types grown on rodent lungs. MATERIAL AND METHODS: Three groups of Fischer rats underwent subpleural generation of sarcoma, mesothelioma, or adenocarcinoma tumors on the left lung. At least five animals of each group (sarcoma, n = 5; mesothelioma, n = 7; adenocarcinoma, n = 5) underwent intraoperative low-dose (10 J/cm(2) at 35 mW/cm(2) ) PDT with 0.0625 mg/kg Visudyne® of the tumor and the lower lobe. This was followed by intravenous (IV) administration of 400 µg Liporubicin™. After a circulation time of 60 min, the tumor-bearing lung was processed for HPLC analyses. At least five animals per group underwent the same procedure but without PDT (sarcoma, n = 5; mesothelioma, n = 5; adenocarcinoma, n = 6). Five untreated animals per group underwent CD31 immunostaining of their tumors with histomorphometrical assessment of the tumor vascularization. RESULTS: Low-dose PDT significantly enhanced Liporubicin™ uptake to all tumor types (sarcoma, P = 0.0007; mesothelioma, P = 0.001; adenocarcinoma, P = 0.02) but not to normal lung tissue compared to IV drug administration alone. PDT led to a significantly increased ratio of tumor to lung tissue drug uptake for all three tumor types (P < 0.05). However, the tumor drug uptake varied between tumor types and paralleled tumor vascular density. The vascular density was significantly higher in sarcoma than in adenocarcinoma (P < 0.001) and mesothelioma (P < 0.001), whereas there was no significant difference between adenocarcinoma and mesothelioma. CONCLUSION: Low-dose Visudyne®-mediated PDT selectively enhances the uptake of systemically administered liposomal doxorubicin in tumors without affecting the drug uptake to normal lung. However, drug uptake varied significantly between tumor types and paralleled tumor vascular density.

Avaluació de la qualitat de vida dels pacients amb tumor vesical sotmesos a tractament amb BCG o Mitomicina endovesical

El tumor vesical superficial és la neoplàsia més comuna de l’aparell genitourinari. El tractament d’elecció és la RTU vesical, però moltes vegades precisa d’adjuvància posterior, com les instil•lacions de BCG o Mitomicina C endovesicals. Aquests tractaments no estan exempts d’efectes adversos, que poden afectar la qualitat de vida dels pacients als quals se’ls administra. La qualitat de vida relacionada amb la salut és una eina important per valorar l’impacte que tenen alguns procediments terapèutics. Mitjançant qüestionaris de salut es pretén avaluar-ho. S’ha intentat crear un qüestionari que pugui utilitzar-se en la pràctica diària pels pacients que reben tractament amb quimioteràpia o immunoteràpia endovesical.

Survival, development and growth of larvae of the blue swimmer crab, Portunus pelagicus, cultured under different photoperiod conditions

The blue swimmer crab is a commercially important species of the tropical Indo-Pacific regions that shows substantial potential as a candidate species for aquaculture. Optimization of larval rearing conditions, including photoperiod, is therefore important to establish a method for the intensive hatchery culture of this species. Newly hatched larvae of Portunuspelagicus in first zoeal stage (ZI) were reared under five photoperiod regimes 0L: 24D, 6L: 18D, 12L: 12D, 18L: 6D, and 24L: 0D (5 replicates per treatment) till they metamorphosed to megalopae (ranged from 8.5 ± 0.3 days (18L: 6D) to 10.8 ± 1.8 days (0L: 24D) at 29 ± 1 °C). Daily, larvae of each treatment were fed an identical diet of mixed rotifer and Artemia nauplii, and the survival and molt to successive stages was monitored. Newly hatched ZI larvae of P. pelagicus could successfully develop to the megalopal stage under all tested photoperiod conditions, but we detected significant differences in survival among treatments (p & 0.05). The constant darkness treatment (0L: 24D) had the lowest (19.2 ± 7.2%, mean ± S.E.) cumulative survival from ZI to the megalopal stage, while the 18L: 6D treatment achieved the highest survival (51.2 ± 23.6%). Similarly, the photoperiod significantly affected zoeal development. Constant darkness led to the longest cumulative zoeal duration (10.8 ± 1.8 days), whereas the 18L: 6D treatment rendered the shortest larval development (8.5 ± 0.3 days). In addition, larvae reared under constant darkness resulted in the smallest megalopae (carapace length = 1.44 ± 0.09 mm) and the lowest dry weight (0.536 ± 0.188 mg). In conclusion, photoperiod significantly affected the survival, development, and growth of P. pelagicus zoeal larvae. Constant darkness led to the lowest larval survival and developmental rate, while a photoperiod regime of 18L: 6D appeared to be the most suitable condition for the rearing of zoeal larvae of P. pelagicus.

VEGF is required for growth and survival in neonatal mice.

We employed two independent approaches to inactivate the angiogenic protein VEGF in newborn mice: inducible, Cre-loxP- mediated gene targeting, or administration of mFlt(1-3)-IgG, a soluble VEGF receptor chimeric protein. Partial inhibition of VEGF achieved by inducible gene targeting resulted in increased mortality, stunted body growth and impaired organ development, most notably of the liver. Administration of mFlt(1-3)-IgG, which achieves a higher degree of VEGF inhibition, resulted in nearly complete growth arrest and lethality. Ultrastructural analysis documented alterations in endothelial and other cell types. Histological and biochemical changes consistent with liver and renal failure were observed. Endothelial cells isolated from the liver of mFlt(1-3)-IgG-treated neonates demonstrated an increased apoptotic index, indicating that VEGF is required not only for proliferation but also for survival of endothelial cells. However, such treatment resulted in less significant alterations as the animal matured, and the dependence on VEGF was eventually lost some time after the fourth postnatal week. Administration of mFlt(1-3)-IgG to juvenile mice failed to induce apoptosis in liver endothelial cells. Thus, VEGF is essential for growth and survival in early postnatal life. However, in the fully developed animal, VEGF is likely to be involved primarily in active angiogenesis processes such as corpus luteum development.

Attenuation of colon inflammation through activators of the retinoid X receptor (RXR)/peroxisome proliferator-activated receptor gamma (PPARgamma) heterodimer. A basis for new therapeutic strategies.

The peroxisome proliferator-activated receptor gamma (PPARgamma) is highly expressed in the colon mucosa and its activation has been reported to protect against colitis. We studied the involvement of PPARgamma and its heterodimeric partner, the retinoid X receptor (RXR) in intestinal inflammatory responses. PPARgamma(1/)- and RXRalpha(1/)- mice both displayed a significantly enhanced susceptibility to 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis compared with their wild-type littermates. A role for the RXR/PPARgamma heterodimer in the protection against colon inflammation was explored by the use of selective RXR and PPARgamma agonists. TNBS-induced colitis was significantly reduced by the administration of both PPARgamma and RXR agonists. This beneficial effect was reflected by increased survival rates, an improvement of macroscopic and histologic scores, a decrease in tumor necrosis factor alpha and interleukin 1beta mRNA levels, a diminished myeloperoxidase concentration, and reduction of nuclear factor kappaB DNA binding activity, c-Jun NH(2)-terminal kinase, and p38 activities in the colon. When coadministered, a significant synergistic effect of PPARgamma and RXR ligands was observed. In combination, these data demonstrate that activation of the RXR/PPARgamma heterodimer protects against colon inflammation and suggest that combination therapy with both RXR and PPARgamma ligands might hold promise in the clinic due to their synergistic effects.

The role of neutralizing antibodies for mouse mammary tumor virus transmission and mammary cancer development.

Mouse mammary tumor virus (MMTV) infection establishes chronic germinal centers and a lifelong neutralizing Ab response. We show that removal of the draining lymph node after establishment of the germinal center reaction led to complete loss of neutralizing Abs despite comparable infection levels in peripheral lymphocytes. Importantly, in the absence of neutralization, only the exocrine organs mammary gland, salivary gland, pancreas, and skin showed strikingly increased infection, resulting in accelerated mammary tumor development. Induction of stronger neutralization did not influence chronic infection levels of peripheral lymphoid organs but strongly inhibited mammary gland infection and virus transmission to the next generation. Taken together, we provide evidence that a tight equilibrium in virus neutralization allows limited infection of exocrine organs and controls cancer development in susceptible mouse strains. These experiments show that a strong neutralizing Ab response induced after infection is not able to control lymphoid MMTV infection. Strong neutralization, however, is capable of blocking amplification of mammary gland infection, tumor development, and virus transmission to the next generation. The results also indicate a role of neutralization in natural resistance to MMTV infection.

The beta-catenin--TCF-1 pathway ensures CD4(+)CD8(+) thymocyte survival.

The association of trans-acting T cell factors (TCFs) or lymphoid enhancer factor 1 (LEF-1) with their coactivator beta-catenin mediates transient transcriptional responses to extracellular Wnt signals. We show here that T cell maturation depends on the presence of the beta-catenin--binding domain in TCF-1. This domain is necessary to mediate the survival of immature CD4(+)CD8(+) double-positive (DP) thymocytes. Accelerated spontaneous thymocyte death in the absence of TCF-1 correlates with aberrantly low expression of the anti-apoptotic protein Bcl-x(L). Increasing anti-apoptotic effectors in thymocytes by the use of a Bcl-2 transgene rescued TCF-1-deficient DP thymocytes from apoptosis. Thus, TCF-1, upon association with beta-catenin, transiently ensures the survival of immature T cells, which enables them to generate and edit T cell receptor (TCR) alpha chains and attempt TCR-mediated positive selection.