Selective cytotoxicity of betulinic acid on tumor cell lines, but not on normal cells

Betulinic acid is a triterpene with selective cytotoxicity against melanoma, neuroectodermal and malignant brain tumor cell lines. In this study the betulinic acid activity was evaluated, in comparison with doxorubicin, on different human neoplastic and non-neoplastic cell lines and on proliferating normal lymphocytes. Growth inhibition was evident in all the neoplastic cell lines independently on p53 status and histotype. Antiproliferative activity of betulinic acid was related to a cytotoxic effect on two p53 wild-type and on one p53 mutant cell lines and to a cytostatic effect on one p53 mutant melanoma clone. At the same concentrations, normal cells were unaffected indicating a selective effect of this agent. A cytotoxic activity of doxorubicin was evident on all the tested systems. In vivo experiments, performed on one of these cell lines, confirmed the antineoplastic activity of this drug. These data support further preclinical studies of betulinic acid not confined to melanoma and neuroectodermal tumors independently of p53 status.

In vitro and in vivo activity of SKI-606, a novel Src-Abl inhibitor, against imatinib-resistant Bcr-Abl+ neoplastic cells

Resistance to imatinib represents an important scientific and clinical issue in chronic myelogenous leukemia. In the present study, the effects of the novel inhibitor SKI-606 on various models of resistance to imatinib were studied. SKI-606 proved to be an active inhibitor of Bcr-Abl in several chronic myelogenous leukemia cell lines and transfectants, with IC(50) values in the low nanomolar range, 1 to 2 logs lower than those obtained with imatinib. Cells expressing activated forms of KIT or platelet-derived growth factor receptor (PDGFR), two additional targets of imatinib, were unaffected by SKI-606, whereas activity was found against PIM2. SKI-606 retained activity in cells where resistance to imatinib was caused by BCR-ABL gene amplification and in three of four Bcr-Abl point mutants tested. In vivo experiments confirmed SKI-606 activity in models where resistance was not caused by mutations as well as in cells carrying the Y253F, E255K, and D276G mutations. Modeling considerations attribute the superior activity of SKI-606 to its ability to bind a conformation of Bcr-Abl different from imatinib.

In vivo eradication of human BCR/ABL-positive leukemia cells with an ABL kinase inhibitor

BACKGROUND

The leukemia cells of approximately 95% of patients with chronic myeloid leukemia and 30%-50% of adult patients with acute lymphoblastic leukemia express the Bcr/Abl oncoprotein, which is the product of a fusion gene created by a chromosomal translocation [(9:22) (q34;q11)]. This oncoprotein expresses a constitutive tyrosine kinase activity that is crucial for its cellular transforming activity. In this study, we evaluated the antineoplastic activity of CGP57148B, which is a competitive inhibitor of the Bcr/Abl tyrosine kinase.

METHODS

Nude mice were given an injection of the Bcr/Abl-positive human leukemia cell lines KU812 or MC3. Tumor-bearing mice were treated intraperitoneally or orally with CGP57148B according to three different schedules. In vitro drug wash-out experiments and in vivo molecular pharmacokinetic experiments were performed to optimize the in vivo treatment schedule.

RESULTS

Treatment schedules administering CGP57148B once or twice per day produced some inhibition of tumor growth, but no tumor-bearing mouse was cured. A single administration of CGP57148B caused substantial (>50%) but short-lived (2-5 hours) inhibition of Bcr/Abl kinase activity. On the basis of the results from in vitro wash-out experiments, 20-21 hours was defined as the duration of continuous exposure needed to block cell proliferation and to induce apoptosis in these two leukemia cell lines. A treatment regimen assuring the continuous block of the Bcr/Abl phosphorylating activity that was administered over an 11-day period cured 87%-100% of treated mice.

CONCLUSION

These data indicate that the continuous block of the oncogenic tyrosine kinase of Bcr/Abl protein is needed to produce important biologic effects in vivo.

Inhibition of the ABL kinase activity blocks the proliferation of BCR/ABL+ leukemic cells and induces apoptosis

The BCR/ABL fusion protein transforms myeloid stem cells. Both chronic myelogenous leukemias (CML) and a subset of acute lymphoblastic leukemias (ALL) are associated with the expression of BCR/ABL proteins. This knowledge has not yet been translated into any specific tool to control ABL driven neoplastic cells growth. CGP57148B is an ATP-competitive inhibitor of the ABL protein kinase; it has been shown to inhibit the kinase activity of ABL both in vitro and in vivo and to inhibit the growth of v-abl and bcr/abl transfectants, as well as the in vitro formation of bone marrow (BM)-derived colonies in the presence of growth factors in some CML patients. These studies were performed to investigate the activity of CGP57148B on the spontaneous proliferation of both fresh and cultured, leukemic and normal, BCR/ABL positive and negative cells, and to study its mechanism of action. Six cell lines derived from BCR/ABL+ leukemias (K562, BV173, KCL22, KU812, MC3, LAMA84), thirteen BCR/ABL negative lines, both neoplastic (KG1, SU-DHL-1, U937, Daudi, NB4, NB4.306) and derived from normal cells (PHA blasts, LAK, fibroblasts, LCL, renal epithelial cells, endothelial cells, CD34(+) cells), and 14 fresh leukemic samples were tested using a tritiated thymidine uptake assay. The in vivo phosphorylation of the BCR/ABL protein was evaluated by western blot, while apoptosis was detected by the annexin V/propidium binding test. The induction of differentiation was assayed by immunofluorescence using multiple antibodies. All six BCR/ABL+ lines showed a dose dependent inhibition of their spontaneous proliferative rate, which was not accompanied by differentiation. The treatment caused, within minutes, dephosphorylation of the BCR/ABL protein, followed in 16-24 hours by a decrease in cycling cells and induction of apoptosis. No significant inhibition of DNA synthesis was observed in any BCR/ABL negative normal or neoplastic line at concentrations </=3 microM, with the exception of fibroblasts and CD34 cells. Proliferation inhibition was observed also when using fresh samples obtained from two Ph+ ALL and 12 consecutive CML patients. Induction of apoptosis was observed in these samples too. The activity of CGP57148B can be monitored in ex vivo isolated or cultured cells using a simple and reproducible assay, without the need for exogenously added growth factors. This molecule possibly exerts its effects through the inhibition of the kinase activity of BCR/ABL and the subsequent initiation of apoptosis, without inducing cell differentiation. Some normal cells are also affected. These data support the use of CGP57148B in initial clinical studies; possible toxic effects on BM and fibroblast-derived cells will have to be closely monitored. The in vivo monitoring of patients will have to be focused on the induction of apoptosis in leukemic cells.

Photoreduction of the fluorescent dye 2'-7'-dichlorofluorescein: a spin trapping and direct electron spin resonance study with implications for oxidative stress measurements

The photoreduction of 2'-7'-dichlorofluorescein (DCF) was investigated in buffer solution using direct electron spin resonance (ESR) and the ESR spin-trapping technique. Anaerobic studies of the reaction of DCF in the presence of reducing agents demonstrated that during visible irradiation (lambda > 300 nm) 2'-7'-dichlorofluorescein undergoes one-electron reduction to produce a semiquinone-type free radical as demonstrated by direct ESR. Spin-trapping studies of incubations containing DCF, 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and either reduced glutathione (GSH) or reduced NADH demonstrate, under irradiation with visible light, the production of the superoxide dismutase-sensitive DMPO/*OOH adduct. In the absence of DMPO, measurements with a Clark-type oxygen electrode show that molecular oxygen is consumed in a light-dependent process. The semiquinone radical of DCF, when formed in an aerobic system, is immediately oxidized by oxygen, which regenerates the dye and forms superoxide.

Denosumab in advanced/unresectable giant-cell tumour of bone (GCTB): For how long?

BACKGROUND

Giant-cell tumours of bone (GCTB) are RANK/RANK-ligand (RANKL) positive, aggressive and progressive osteolytic tumours. Denosumab, a RANKL inhibitor, was FDA-approved for adults and skeletally mature adolescents with unresectable GCTB or when surgical resection is likely to result in severe morbidity. Data on long-term toxicity and activity of denosumab monthly 'GCTB-schedule' (120 mg per 12/year, 1440 mg total dose/year) are lacking.

METHODS

Patients with GCTB receiving denosumab, 120 mg on days 1, 8, 15, 29 and every 4 weeks thereafter, from 2006 to 2015 treated in two centres were included. Long-term toxicity was evaluated.

RESULTS

Ninety-seven patients were identified. 43 patients underwent resection of the tumour with a median time on denosumab treatment of 12 months (range 6-45 months). Fifty-four patients had unresectable GCTB's (male/female 23/31, median age 35 years [range: 13-76 years], 26% presented with lung metastases, 31% had primary tumor located to the spine, 63% were relapsed after previous surgery) with a median time on denosumab of 54 months (9-115 months). In the unresectable GCTB group, tumour control and clinical benefits were observed in all patients undergoing denosumab, whereas 40% of patients discontinuing denosumab had tumour progression after a median of 8 months (range 7-15 months).

ADVERSE EVENTS

Overall, six (6%) patients developed osteonecrosis of jaw (ONJ): 1/43 (2%) in the resectable group, 5/54 (9%) in the unresectable group, with a 5-year ONJ-free survival of 92% (95% CI 84-100). Only patients with prolonged treatment experienced mild peripheral neuropathy (6/54, 11%), skin rash (5/54, 9%), hypophosphataemia (2/54, 4%) and atypical femoral fracture (2/54, 4%).

CONCLUSIONS

Prolonged treatment with denosumab has sustained activity in GCTB, with a mild toxicity profile. The dose-dependent toxicity observed recommends a careful and strict monitoring of patients who need prolonged treatment. Decreased dose-intensity schedules should be further explored in unresectable GCTB.

Demonstrable cardiac reinnervation after human heart transplantation by carotid baroreflex modulation of RR interval

BACKGROUND

After heart transplantation, respiration-synchronous fluctuations (0.18 to 0.35 Hz, high frequency [HF]) in RR interval may result from atrial stretch caused by changes in venous return, but slower fluctuations (0.03 to 0.15 Hz, low frequency [LF]) not due to respiration suggest reinnervation. In normal subjects, sinusoidal neck suction selectively stimulates carotid baroreceptors and causes reflex oscillations of RR interval.

METHODS AND RESULTS

To evaluate the presence of reinnervation, we measured the power of RR-LF and RR-HF in 26 heart transplant recipients and 16 control subjects before and during sinusoidal neck suction at 0.1 Hz and 0.20 Hz (similar to but distinct from that of controlled respiration, 0.25 Hz) and before and during administration of atropine or beta-blocker (esmolol hydrochloride) by spectral analysis. All transplant recipients showed small respiratory HF fluctuations. Nonrespiratory LF fluctuations were present in 13 of 26 transplant recipients and increased with months since transplantation (r = .53, P < .01). HF neck suction induced a 0.20-Hz component in all 16 control subjects and none of the 26 transplant subjects. LF neck suction increased RR-LF (from 0.73 +/- 0.20 to 1.30 +/- 0.26 ln ms2, P < .001), similar to but less than in control subjects (from 6.12 +/- 0.21 to 8.27 +/- 0.21 ln ms2, P < .001). Atropine reduced all fluctuations in control subjects and blocked the HF increase caused by 0.20-Hz neck suction but not the LF increase during 0.10-Hz stimulation. Neck suction-induced changes in LF fluctuations persisted after administration of atropine in transplant recipients but were attenuated by esmolol hydrochloride, suggesting sympathetic rather than vagal reinnervation.

CONCLUSIONS

The presence of baroreceptor-induced RR oscillations is evidence of functional, although incomplete, autonomic reinnervation.

Cardiovascular autonomic modulation in essential hypertension. Effect of tilting

To better understand the role played by the autonomic nervous system in essential hypertension, we used autoregressive power spectrum analysis to study the noncasual oscillations in RR interval, blood pressure, and skin blood flow in 40 subjects with mild to moderate hypertension and in 25 age-matched control subjects at low frequency (index of sympathetic activity to the heart and the peripheral circulation) and high frequency, respiratory related (index of vagal tone to the heart). RR interval, respiration, noninvasive systolic blood pressure, and skin arteriolar blood flow were simultaneously and continuously recorded with subjects in the supine position and immediately after tilting. The low-frequency component was not significantly different in the two groups either at the cardiac level (control versus hypertensive subjects: 39.1 +/- 4.3 versus 39.9 +/- 3.7 normalized units [NU]) or at the vascular level (1.52 +/- 0.17 versus 1.69 +/- 0.13 ln mm Hg2). After head-up tilting, the RR interval fluctuations were less in hypertensive subjects (low-frequency components from 39.9 +/- 3.7 to 48.4 +/- 4.1 NU, P < .05; high-frequency components from 53.9 +/- 3.7 to 44 +/- 4 NU, P < .05) than in control subjects (low-frequency components from 39.1 +/- 4.3 to 64.4 +/- 4.9 NU, P < .001; high-frequency components from 56.0 +/- 4.5 to 31.2 +/- 4.6 NU, P < .001); the low-frequency components in systolic blood pressure increased similarly in hypertensive subjects (to 2.43 +/- 0.17 ln mm Hg2, P < .0001) and in control subjects (to 2.44 +/- 0.21 ln mm Hg2, P < .01), but the low-frequency components in skin blood flow increased only in control subjects (from 5.34 +/- 0.45 to 6.55 +/- 0.53 mm Hg2, P < .01), not in hypertensive subjects (from 5.55 +/- 0.34 to 5.60 +/- 0.35 ln mm Hg2). In hypertensive subjects with left ventricular hypertrophy, the low-frequency components in systolic blood pressure did not increase after tilting (from 1.75 +/- 0.33 to 2.05 +/- 0.41 ln mm Hg2). Baroreflex sensitivity, as assessed by spectrum analysis, was significantly lower in hypertensive than in control subjects (5.17 +/- 0.49 versus 13.18 +/- 2.44 ms/mm Hg, P < .001. Power spectrum analysis did not reveal an increased sympathetic activity or reactivity either at the cardiac or at the vascular level. The decreased baroreceptor sensitivity in hypertensive subjects could explain the reduced change in sympathovagal balance in the tilt position at the cardiac level. In hypertensive subjects without left ventricular hypertrophy, cardiopulmonary reflex deactivation induced by tilting and/or amplification of sympathetic nervous tone by arteriolar structural change could have preserved the sympathetic activation at the vascular level.

Gemcitabine and docetaxel in relapsed and unresectable high-grade osteosarcoma and spindle cell sarcoma of bone

BACKGROUND

Few new compounds are available for relapsed osteosarcoma. We retrospectively evaluated the activity of gemcitabine (G) plus docetaxel (D) in patients with relapsed high-grade osteosarcoma and high-grade spindle cell sarcoma of bone (HGS).

METHODS

Patients receiving G 900 mg/m(2) d 1, 8; D 75 mg/m(2) d 8, every 21 days were eligible. Primary end-point: progression-free survival (PFS) at 4 months; secondary end-point: overall survival (OS) and response rate.

RESULTS

Fifty-one patients were included, with a median age of 17 years (8-71), 26 (51%) were pediatric patients. GD line of treatment: 2nd in 14 patients, ≥3rd in 37. 25 (49%) patients had metastases limited to lungs, 26 (51%) multiple sites.

HISTOLOGY

40 (78%) osteosarcoma, 11 (22%) HGS. Eight (16%) patients achieved surgical complete response (sCR2) after GD. Four-month PFS rate was 46%, and significantly better for patients with ECOG 0 (ECOG 0: 54% vs ECOG 1: 43% vs ECOG 2: 0%; p = 0.003), for patients undergoing metastasectomy after GD (sCR2 75% vs no-sCR2 40 %, p = 0.02) and for osteosarcoma (osteosarcoma 56% vs HGS 18%; p = 0.05), with no differences according to age, line of treatment, and pattern of metastases. Forty-six cases had RECIST measurable disease: 6 (13%) patients had a partial response (PR), 20 (43%) had stable disease (SD) and 20 (43%) had progressive disease (PD). The 1-year OS was 30%: 67% for PR, 54% for SD and 20% for PD (p = 0.005).

CONCLUSIONS

GD is an active treatment for relapsed high-grade osteosarcoma, especially for ECOG 0 patients, and should be included in the therapeutic armamentarium of metastatic osteosarcoma.

Low-density lipoprotein oxidation in essential hypertension

OBJECTIVES

To investigate the occurrence of enhanced low-density lipoprotein (LDL) oxidation as an additional factor promoting atherosclerosis progression in hypertensive patients.

DESIGN

The oxidation of plasma LDL was investigated in a group of untreated patients with mild-to-moderate essential hypertension without clinically evident target organ damage and in a group of control subjects.

METHODS

LDL oxidation was evaluated as both the susceptibility to oxidation in vitro and the presence of plasma anti-oxidized LDL antibodies (as an index for oxidation in vivo).

RESULTS

LDL from hypertensive subjects exhibited enhanced susceptibility to oxidation in vitro as revealed by early and accelerated generation of conjugated dienes after exposure to CuSO4. Vitamin E concentration in LDL from hypertensive subjects was slightly but significantly decreased and its efficiency in protecting LDL from oxidation was impaired. Furthermore, a higher plasma anti-oxidized LDL titre was found in hypertensive patients. Subclass analysis revealed that the contemporary presence of hypercholesterolaemia did not significantly modify either the increased susceptibility of LDL to oxidation or the presence of plasma anti-oxidized LDL antibodies detected in hypertensive patients. Moreover, no correlation was found between LDL oxidation parameters and blood pressure values.

CONCLUSIONS

LDL from hypertensive patients is more susceptible to oxidation in vitro and is more promptly oxidized in vivo. These findings suggest a possible participation of LDL oxidation in promoting and accelerating the atherosclerosis that often develops in hypertensive patients.

Protective effects of carvedilol, a vasodilating beta-adrenoceptor blocker, against in vivo low density lipoprotein oxidation in essential hypertension

Low density lipoprotein (LDL) oxidation plays a crucial role in the development and progression of atherosclerosis and is enhanced in patients with essential hypertension. This finding has stimulated a search for antihypertensive drugs with high intrinsic antioxidant properties. We investigated the antihypertensive and antioxidant effects of carvedilol, a new vasodilating beta-adrenoceptor blocking agent in a group of patients with mild to moderate essential hypertension after 4-month treatment. Carvedilol administration markedly increased the resistance to oxidation of LDL isolated from treated patients to values comparable to those of control, nonhypertensive subjects. This effect was achieved despite a significant loss in LDL-associated vitamin E. The increased resistance of LDL to oxidation promoted by carvedilol was not related to the normalization of previously increased blood pressure (BP). Indeed, the administration of other conventional antihypertensive drugs, capable of decreasing arterial BP but without high intrinsic antioxidant properties, to a control group of matched hypertensive patients failed to ameliorate LDL oxidation parameters. Carvedilol treatment also reduced the extent of in vivo LDL oxidation, as reflected by the decrease in antioxidized LDL autoantibody titer. This effect as well was detected only in the group of carvedilol-treated hypertensive patients and not after the simple reduction in BP obtained with antihypertensive drugs different from carvedilol.

The nature of prooxidant activity of vitamin C

It was recently reported that vitamin C (500 mg/day for 6 weeks) administered as a dietary supplement to healthy humans exhibits a prooxidant, as well as an antioxidant effect in vivo. Here we show that high intakes of vitamin C (500 mg/kg b.w. for 4 days) in the rat are able to markedly induce hepatic cytochrome P4502E1-linked monooxygenases, measured as p-nitrophenol hydroxylase activity and corroborated by means of Western blot analyses. Furthermore, using Electron Paramagnetic Resonance Spectroscopy (EPR) coupled to a spin-trapping technique, we have also found that this induction generates large amounts of the anion radical superoxide (O2-). Therefore we can conclude that the adverse prooxidant outcomes (i.e. oxidative DNA damage) associated to vitamin C supplementation, being associated to a typical reversible boosting effect (i.e. enzymatic induction), may be easily controlled by a discontinuous supply. However, since the induced P4502E1 isoforms by vitamin C are responsible for ethanol metabolism to highly reactive radicals, care should be taken even in moderate drinkers.

Functional Genomics Uncover the Biology behind the Responsiveness of Head and Neck Squamous Cell Cancer Patients to Cetuximab

PURPOSE

To identify the tumor portrait of the minority of head and neck squamous cell carcinoma (HNSCC) patients with recurrent-metastatic (RM) disease who upon treatment with platinum-based chemotherapy plus cetuximab present a long-lasting response.

EXPERIMENTAL DESIGN

The gene expression of pretreatment samples from 40 HNSCC-RM patients, divided in two groups [14 long-progression-free survival (PFS) and 26 short-PFS (median = 19 and 3 months, respectively)], was associated with PFS and was challenged against a dataset from metastatic colon cancer patients treated with cetuximab. For biologic analysis, we performed functional and subtype association using gene set enrichment analysis, associated biology across all currently available HNSCC signatures, and inferred drug sensitivity using data from the Cancer Genomic Project.

RESULTS

The identified genomic profile exhibited a significant predictive value that was essentially confirmed in the single publicly available dataset of cetuximab-treated patients. The main divergence between long- and short-PFS groups was based on developmental/differentiation status. The long-PFS patients are characterized by basal subtype traits such as strong EGFR signaling phenotype and hypoxic differentiation, further validated by the significantly higher association with the hypoxia metagene. The short-PFS patients presented a strong activation of RAS signaling confirmed in an in vitro model of two isogenic HNSCC cell lines sensitive or resistant to cetuximab. The predicted drug sensitivity for all four EGFR inhibitors was higher in long- versus short-PFS patients (P range: <0.0022-1e-07).

CONCLUSIONS

Our data uncover the biology behind response to platinum-based chemotherapy plus cetuximab in RM-HNSCC cancer and may have translational implications improving treatment selection. Clin Cancer Res; 22(15); 3961-70. ©2016 AACRSee related commentary by Chau and Hammerman, p. 3710.

miR-342 regulates BRCA1 expression through modulation of ID4 in breast cancer

A miRNAs profiling on a group of familial and sporadic breast cancers showed that miRNA-342 was significantly associated with estrogen receptor (ER) levels. To investigate at functional level the role of miR-342 in the pathogenesis of breast cancer, we focused our attention on its "in silico" predicted putative target gene ID4, a transcription factor of the helix-loop-helix protein family whose expression is inversely correlated with that of ER. ID4 is expressed in breast cancer and can negatively regulate BRCA1 expression. Our results showed an inverse correlation between ID4 and miR-342 as well as between ID4 and BRCA1 expression. We functionally validated the interaction between ID4 and miR-342 in a reporter Luciferase system. Based on these findings, we hypothesized that regulation of ID4 mediated by miR-342 could be involved in the pathogenesis of breast cancer by downregulating BRCA1 expression. We functionally demonstrated the interactions between miR-342, ID4 and BRCA1 in a model provided by ER-negative MDA-MB-231 breast cancer cell line that presented high levels of ID4. Overexpression of miR-342 in these cells reduced ID4 and increased BRCA1 expression, supporting a possible role of this mechanism in breast cancer. In the ER-positive MCF7 and in the BRCA1-mutant HCC1937 cell lines miR-342 over-expression only reduced ID4. In the cohort of patients we studied, a correlation between miR-342 and BRCA1 expression was found in the ER-negative cases. As ER-negative cases were mainly BRCA1-mutant, we speculate that the mechanism we demonstrated could be involved in the decreased expression of BRCA1 frequently observed in non BRCA1-mutant breast cancers and could be implicated as a causal factor in part of the familial cases grouped in the heterogeneous class of non BRCA1 or BRCA2-mutant cases (BRCAx). To validate this hypothesis, the study should be extended to a larger cohort of ER-negative cases, including those belonging to the BRCAx class.

Identification of a chrXq27.3 microRNA cluster associated with early relapse in advanced stage ovarian cancer patients

A major challenge in advanced-stage epithelial ovarian cancer (EOC) is prediction of chemoresistant relapse. Our aim was to identify a microRNA (miRNA) signature associated with early relapse in advanced-stage EOC patients. miRNA expression was assessed by microarray profiling in training (n = 55) and test (n = 30) sets selected on the basis of time to relapse (TTR), followed by internal quantitative reverse transcriptase-PCR validation on a set of 45 consecutive cases unselected for clinical response and external in silico validation on publicly available datasets. Thirty-two differentially expressed miRNAs in early vs. late relapsing patients were identified in the training set. In the test set, 8 of these, belonging to a cluster located on chrXq27.3, were down-modulated in early relapsing patients. Hierarchical clustering of the internal validation set according to chrXq27.3 miRNA expression associated low miRNA expression with shorter TTR (log-rank P=0.00074, HR 2.44). The cluster was an independent prognostic factor in both internal and external validation sets. Forced expression of chrXq27.3-cluster selected miRNAs in human EOC cellular models was associated to reduction of cell proliferation and increased sensitivity to cisplatin. The role of down-modulation of the chrXq27.3 miRNA cluster in early relapse of advanced-stage EOC patients and its association to a reduced sensitivity to chemotherapeutic treatments warrant further investigation.

Constitutive activation of Jak2 contributes to proliferation and resistance to apoptosis in NPM/ALK-transformed cells

OBJECTIVE

The t(2;5) translocation results in a 80-kDa oncogenic fusion protein consisting of NPM and the kinase domain of the tyrosine kinase ALK and is present in over half the cases of anaplastic large cell lymphoma (ALCL). NPM/ALK exerts its transforming potential via activation of multiple signaling pathways promoting growth factor independence and protection from apoptosis. Jak/Stat signaling is aberrantly activated in several human hematopoietic malignancies. We investigated the role of Jak2 in the context of NPM/ALK-mediated oncogenesis.

MATERIALS AND METHODS

Constitutive tyrosine phosphorylation of Jak2 was analyzed by Jak2 immunoprecipitation and subsequent anti-phosphotyrosine Western blotting. NPM/ALK-transformed cells were treated with the Jak2 inhibitor AG490 or transfected with wild-type or dominant-negative Jak2 expression constructs to measure 3[H]-thymidine incorporation. Apoptosis was assessed by flow cytometric analysis of annexin V-stained cells. The effect of Jak2 on Stat5-dependent transcriptional activity was measured by beta-casein promoter-dependent luciferase expression.

RESULTS

Jak2 was found to be constitutively tyrosine phosphorylated in ALCL cells and in NPM/ALK-transformed hematopoietic cells. Also, NPM/ALK was present in immunoprecipitates of Jak2. Inhibition of Jak2 led to a reduction of NPM/ALK-mediated proliferation and induced apoptosis. Stat5-dependent transcriptional activity was inhibited by transfection of NPM/ALK-transformed cells with a dominant-negative Jak2 expression construct or treatment with AG490.

CONCLUSION

Constitutive activation of Jak2 constitutes a pro-proliferative, anti-apoptotic signaling pathway in NPM/ALK-transformed hematopoietic cells.

Adoptive immunotherapy of advanced melanoma patients with interleukin-2 (IL-2) and tumor-infiltrating lymphocytes selected in vitro with low doses of IL-2

Freshly isolated tumor-infiltrating lymphocytes (TIL) from stage IV melanoma patients were cultured for 2 weeks with low doses of interleukin-2 (IL-2; 120 IU/ml), to select potentially for tumor-specific lymphocytes present in the neoplastic lesion, followed by high doses (6000 IU/ml) to achieve lymphocyte expansion. TIL were serially analyzed for their expansion, phenotype and cytotoxic activity against autologous and allogenic tumor cells. A preferential lysis of autologous melanoma cells was obtained in long-term cultures of 7/13 cases (54%), while the remaining ones showed a major-histocompatibility-complex-unrestricted, lymphokine-activated-killer(LAK)-like activity at the time of in vivo injection. Sixteen patients with metastatic melanoma were infused with TIL (mean number: 6.8 x 10(9), range: 0.35 x 10(9)-20 x 10(9)) and IL-2 (mean dose: 130 x 10(6) IU, range: 28.8 x 10(6)-231 x 10(6) IU); 1 complete and 3 partial responses were observed in 12 evaluable patients (response rate 33%). In all responding patients, injected TIL showed an in vitro preferential lysis of autologous tumor cells, while in no cases were TIL with LAK-like activity associated with a clinical response. The mean autologous tumor cytotoxic activity of TIL at the time of in vivo injection was significantly higher in responding patients in comparison to nonresponding ones, suggesting that a marked and preferential cytolysis of autologous tumor cells is associated with the therapeutic efficacy of TIL.

Effect of enalapril on left ventricular mass and performance in essential hypertension

The effect of enalapril on left ventricular (LV) morphology and function was studied in 12 hypertensive patients. The subjects were evaluated after 2 weeks of placebo and after 4 months of treatment with enalapril (20 or 40 mg once daily), using M-mode digitized echocardiograms. The drug reduced arterial blood pressure in all patients. Systemic vascular resistance decreased significantly without changes in cardiac output and heart rate. No patient had significant side effects. After treatment LV mass decreased significantly (233 +/- 46 to 204 +/- 37 g, p less than 0.01); the reduction was due to a decrease in septal and posterior wall thickness, without changes in LV diameter. LV systolic function remained unchanged, whereas peak lengthening rate of LV dimension, an index of LV diastolic function, increased significantly (4.05 +/- 1.8 to 5.11 +/- 1.8 s-1, p less than 0.01). After treatment the basal inverse correlation between peak shortening rate and wall stress did not change, the inverse correlation between peak lengthening rate and wall stress became closer and the basal inverse correlation between peak lengthening rate and LV mass disappeared. In conclusion, antihypertensive treatment with enalapril led to a significant regression of LV hypertrophy associated with improvement in LV diastolic performance and no deterioration of LV systolic function.

Protective effect of loratadine on late phase reaction induced by conjunctival provocation test

The protective effect of Loratadine, a new generation, non-sedating antihistamine, on clinical and cellular events during the early phase reaction (EPR) and late phase reaction (LPR) of the allergen-specific conjunctival provocation test (CPT) was assessed out of the pollen season in 20 seasonally allergic rhino-conjunctivitis patients. After a screening CPT, selected patients were randomized to Loratadine (10 mg OD) or matching placebo for 7 days. CPT was repeated following treatment. Clinical and cellular responses were evaluated by a symptom score and cell counting in conjunctival scrapings before, and 30 min and 6 h after challenge with allergen (one eye) or placebo (control eye). Conjunctival symptom severity following CPT was reduced at 30 min (EPR) and 6 h (LPR) after CPT in the Loratadine group compared to placebo group (p < 0.01), as was the total number of inflammatory cells (p < 0.001). In conclusion, Loratadine protects against the clinical and cellular EPR and LPR events consequent to CPT, showing antiallergic properties.

Irinotecan and temozolomide in recurrent Ewing sarcoma: an analysis in 51 adult and pediatric patients

BACKGROUND

Data on temozolomide (TEM) and irinotecan (IRI) activity in recurrent Ewing sarcoma (EWS), especially in adult patients, are limited.

METHODS

Patients receiving TEM 100 mg/m²/day oral, and IRI 40 mg/m²/day intravenous, days 1-5, every 21 days, were included in this multi-institutional retrospective study. Disease control rate (DCR) [overall response rate (ORR) [complete response (CR) + partial response (PR)] + stable disease (SD)], 6-months progression-free survival (6-mos PFS) and 1-year overall survival (OS) were assessed.

RESULTS

The median age of the 51 patients was 21 years (range 3-65 years): 34 patients (66%) were adults (≥18 years of age), 24 (48%) had ECOG 1 and 35 (69%) were presented with multiple site recurrence. TEMIRI was used at first relapse/progression in 13 (25%) patients, while the remainder received TEMIRI for second or greater relapse/progression. Fourteen (27%) patients had received prior myeloablative therapy with busulfan and melphalan. We observed five (10%) CR, 12 (24%) PR and 19 (37%) SD, with a DCR of 71%. 6-mos PFS was 49% (95% CI 35-63) and it was significantly influenced by ECOG (6-mos PFS 64% [95% CI 45-83] for ECOG 0, 34% [95% CI 14-54] for ECOG ≥1; p = .006) and LDH (6-mos PFS 62% [95% CI 44-79] for normal LDH, 22% [95% CI 3-42] for high LDH; p = .02), with no difference according to line of treatment, age and metastatic pattern. One-year OS was 55% (95% CI 39-70), with RECIST response (p = .001) and ECOG (p = .0002) independently associated with outcome. Grade 3 and 4 toxicity included neutropenia in 12% of patients, thrombocytopenia in 4%, diarrhea in 4%.

CONCLUSIONS

This series confirms the activity of TEMIRI in both adults and pediatric patients. This schedule offers a 71% DCR, independently of the line of chemotherapy. Predictive factors of response are ECOG and LDH.

Non-respiratory components of heart rate variability in heart transplant recipients: evidence of autonomic reinnervation?

1. Although the high-frequency fluctuations in R-R interval (respiratory sinus arrhythmia) observed in heart transplant recipients are not a reliable marker of reinnervation because of a previously shown direct mechanical effect of breathing, the presence of a non-respiration-related low-frequency oscillation reflects rhythms generated outside the heart, and thus could be neurally mediated. 2. To evaluate the presence of reinnervation, the spontaneous variability in R-R interval was investigated, supine and after passive tilting, in 23 heart transplant recipients (age 43 years, range 23-64 years) and in 25 normotensive control subjects by autoregressive spectral analysis of low- and high-frequency spontaneous fluctuations in R-R interval and respiration. The response of R-R interval to amyl nitrite inhalation was also evaluated in five heart transplant recipients and eight control subjects. 3. Detectable low-frequency oscillations, unrelated to respiration, were present in 13/23 heart transplant recipients, particularly in those who were transplanted at least 20 months earlier (11/14). The natural logarithm of the power of low-frequency fluctuations was markedly lower than in control subjects (0.75 +/- 0.21 versus 5.62 +/- 0.20 ms2, P < 0.001). The low-frequency but not the high-frequency fluctuations correlated with time since transplantation (r = 0.44, P < 0.05). The subjects with low-frequency fluctuations showed a sudden decrease in R-R interval with amyl nitrite linearly related to the decrease in mean blood pressure (r > or = 0.94). The slopes obtained in these heart transplant recipients were comparable (although of lower values) with those obtained in control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of loratadine on specific conjunctival provocation test

The protective effect of loratadine (anti-H1 antagonist) on clinical and cellular processes following the early phase of specific conjunctival provocation test was assessed in 20 patients affected by seasonal allergic rhinoconjunctivitis, in a double-blind, randomized, placebo-controlled, parallel-group study. Patients were randomly assigned to two treatment groups, each being given a single daily dose of loratadine 10 mg or placebo, for 7 days, out of pollen season. Pretreatment with Loratadine resulted in a significant higher allergen threshold dose than placebo (p less than 0.01). Patients treated with loratadine experienced a significant reduction (p less than 0.01) in conjunctival symptom severity as compared with placebo, following conjunctival challenge. Finally, the number of inflammatory cells was lower in the loratadine-treated patients compared to the placebo group (p less than 0.01). In conclusion, loratadine exerts a significant protective effect on the early phase cellular and clinical events of conjunctival reaction induced by allergen challenge in atopic patients.

Inhibitory effect of the H1 antagonist loratadine on histamine release from human basophils

Loratadine is a powerful H1 antagonist commonly employed in the treatment of allergic disorders. The present study was performed to investigate whether loratadine, in addition to anti-H1 activity, is able to modulate histamine release from human basophils. Leukocyte suspensions were prepared by dextran sedimentation of peripheral venous blood drawn from 10 normal subjects. Leukocytes were stimulated with anti-IgE (1/5,000), N-formyl-methionyl-leucyl-phenylalanine (FMLP; 10 microM) and the Ca2+ ionophore A23187 (1 microM), and histamine release in the cell supernatants was measured by an automated fluorometric method. Loratadine, at concentrations ranging from 1 to 50 microM, exerted a dose-dependent inhibitory effect on IgE-mediated and IgE-independent histamine release. The concentrations inhibiting 50% of histamine release were 30 microM (anti-IgE), 29 microM (FMLP) and 24 microM (Ca2+ ionophore A23187). The inhibitory activity of loratadine was optimal after incubation for 2 h at 37 degrees C and the effect of the drug was no longer evident when leukocytes were stimulated 2 h after cell washing. Increased extracellular Ca2+ concentrations reduced the inhibitory activity of loratadine, indicating that external Ca2+ and loratadine have antagonistic effects on basophil histamine release. These results indicate that loratadine, in addition to H1 receptor blocking activity, has the capacity to inhibit histamine release from human basophils.

Integrative miRNA-Gene Expression Analysis Enables Refinement of Associated Biology and Prediction of Response to Cetuximab in Head and Neck Squamous Cell Cancer

This paper documents the process by which we, through gene and miRNA expression profiling of the same samples of head and neck squamous cell carcinomas (HNSCC) and an integrative miRNA-mRNA expression analysis, were able to identify candidate biomarkers of progression-free survival (PFS) in patients treated with cetuximab-based approaches. Through sparse partial least square–discriminant analysis (sPLS-DA) and supervised analysis, 36 miRNAs were identified in two components that clearly separated long- and short-PFS patients. Gene set enrichment analysis identified a significant correlation between the miRNA first-component and EGFR signaling, keratinocyte differentiation, and p53. Another significant correlation was identified between the second component and RAS, NOTCH, immune/inflammatory response, epithelial–mesenchymal transition (EMT), and angiogenesis pathways. Regularized canonical correlation analysis of sPLS-DA miRNA and gene data combined with the MAGIA2 web-tool highlighted 16 miRNAs and 84 genes that were interconnected in a total of 245 interactions. After feature selection by a smoothed t-statistic support vector machine, we identified three miRNAs and five genes in the miRNA-gene network whose expression result was the most relevant in predicting PFS (Area Under the Curve, AUC = 0.992). Overall, using a well-defined clinical setting and up-to-date bioinformatics tools, we are able to give the proof of principle that an integrative miRNA-mRNA expression could greatly contribute to the refinement of the biology behind a predictive model.

Medium effects on the antioxidant activity of dipyridamole

Very strong medium effects have been observed when testing the antioxidant activity of dipyridamole (DP) in different media such as benzene, tert-butanol, methanol solutions and egg yolk lecithin unilamellar and multilamellar vesicles. Actually, dipyridamole behaves as a very poor antioxidant in benzene while its ability to inhibit the lipid peroxidation reaction increases with increasing solvent polarity, being the highest in lipid vesicles. This behavior can not be rationalized on the basis of the classical chain breaking mechanism which operates in the case of phenolic and amine antioxidants and involving the transfer of a hydrogen atom to peroxyl radicals. An explanation is instead given in terms of an electron transfer reaction which leads to the oxidation of DP by the chain carrying peroxyl radical to give the dipyridamole cation radical, DP+*, and the peroxyl anion LOO-, and whose rate constant is expected to increase in strongly polar media. EPR and electrochemical data supporting this interpretation have been collected.