Imetelstat (GRN163L)--telomerase-based cancer therapy

Telomeres and telomerase play essential roles in the regulation of the lifespan of human cells. While normal human somatic cells do not or only transiently express telomerase and therefore shorten their telomeres with each cell division, most human cancer cells typically express high levels of telomerase and show unlimited cell proliferation. High telomerase expression allows cells to proliferate and expand long-term and therefore supports tumor growth. Owing to the high expression and its role, telomerase has become an attractive diagnostic and therapeutic cancer target. Imetelstat (GRN163L) is a potent and specific telomerase inhibitor and so far the only drug of its class in clinical trials. Here, we report on the structure and the mechanism of action of imetelstat as well as about the preclinical and clinical data and future prospects using imetelstat in cancer therapy.

Determinants of sustained viral suppression in HIV-infected patients with self-reported poor adherence to antiretroviral therapy

Background Good adherence to antiretroviral therapy (ART) is critical for successful HIV treatment. However, some patients remain virologically suppressed despite suboptimal adherence. We hypothesized that this could result from host genetic factors influencing drug levels. Methods Eligible individuals were Caucasians treated with efavirenz (EFV) and/or boosted lopinavir (LPV/r) with self-reported poor adherence, defined as missing doses of ART at least weekly for more than 6 months. Participants were genotyped for single nucleotide polymorphisms (SNPs) in candidate genes previously reported to decrease EFV (rs3745274, rs35303484, rs35979566 in CYP2B6) and LPV/r clearance (rs4149056 in SLCO1B1, rs6945984 in CYP3A, rs717620 in ABCC2). Viral suppression was defined as having HIV-1 RNA <400 copies/ml throughout the study period. Results From January 2003 until May 2009, 37 individuals on EFV (28 suppressed and 9 not suppressed) and 69 on LPV/r (38 suppressed and 31 not suppressed) were eligible. The poor adherence period was a median of 32 weeks with 18.9% of EFV and 20.3% of LPV/r patients reporting missed doses on a daily basis. The tested SNPs were not determinant for viral suppression. Reporting missing >1 dose/week was associated with a lower probability of viral suppression compared to missing 1 dose/week (EFV: odds ratio (OR) 0.11, 95% confidence interval (CI): 0.01–0.99; LPV/r: OR 0.29, 95% CI: 0.09–0.94). In both groups, the probability of remaining suppressed increased with the duration of continuous suppression prior to the poor adherence period (EFV: OR 3.40, 95% CI: 0.62–18.75; LPV/r: OR 5.65, 95% CI: 1.82–17.56). Conclusions The investigated genetic variants did not play a significant role in the sustained viral suppression of individuals with suboptimal adherence. Risk of failure decreased with longer duration of viral suppression in this population.

Cytokine and anti-cytokine therapy for asthma

Cytokines play a critical role in the pathogenesis of asthma. Asthma resolution may depend on the correction of dysregulated cytokine expression, which is a characteristic feature of this chronic inflammatory disease. It is, therefore, not surprising that attempts have been made to either block cytokines present at elevated levels or to substitute cytokines that are insufficiently expressed in asthma. In this article, the results of these studies are discussed, and the obtained insights regarding asthma pathogenesis and new treatment options are summarized.

Adenosine diphosphate (ADP) and ADP receptor play a major role in platelet activation/aggregation induced by sera from heparin-induced thrombocytopenia patients

The molecular basis for heparin-induced thrombocytopenia (HIT), a relatively common complication of heparin therapy, is not yet fully understood. We found that pretreatment of platelets with AR-C66096 (formerly FPL 66096), a specific platelet adenosine diphosphate (ADP) receptor antagonist, at a concentration of 100 to 200 nmol/L that blocked ADP-dependent platelet aggregation, resulted in complete loss of platelet aggregation responses to HIT sera. AR-C66096 also totally inhibited HIT serum-induced dense granule release, as judged by measurement of adenosine triphosphate (ATP) release. Apyrase, added to platelets at a concentration that had only minor effects on thrombin- or arachidonic acid-induced aggregation, also blocked completely HIT serum-induced platelet aggregation. Furthermore, AR-C66096 inhibited platelet aggregation and ATP release induced by cross-linking Fc gamma RIIA with specific antibodies. These data show that released ADP and the platelet ADP receptor play a pivotal role in HIT serum-induced platelet activation/aggregation. The thromboxane receptor inhibitor, Daltroban, had no effect on HIT serum-induced platelet activation whereas GPIIb-IIIa antagonists blocked platelet aggregation but had only a moderate effect on HIT serum-induced dense granule release. Pretreatment of platelets with chondroitinases but not with heparinases resulted in concentration dependent inhibition of HIT serum-induced platelet aggregation. These novel data relating to the mechanism of platelet activation induced by HIT sera suggest that the possibility should be examined that ADP receptor antagonists or compounds that inhibit ADP release may be effective as therapeutic agents for the prevention or treatment of complications associated with heparin therapy.

Plasma leptin levels in men are not related to the development of lipoatrophy during antiretroviral therapy

OBJECTIVES: To assess the correlations between the hormone leptin and lipoatrophy in HIV-positive, treatment-naive patients on combination antiretroviral therapy (cART). DESIGN: Case-control study nested in a multicentre cohort of HIV-infected adults. Cases were patients that developed lipoatrophy and controls those who did not. PATIENTS AND METHODS: Clinical parameters and plasma leptin determinations were studied in 97 HIV-1-infected, treatment-naive Caucasian men (10 cases and 87 controls) on an unchanged and virologically successful drug regimen with a zidovudine/lamivudine backbone at baseline and after 2 years of cART. The association of plasma leptin levels and the development of lipoatrophy was investigated. RESULTS: Two years of cART was not associated with a change in plasma leptin levels. Plasma leptin levels remained sensible to changes in body mass index. There was no difference in leptin levels between patients who developed lipoatrophy and controls, neither before nor after cART. The only predictor of development of lipoatrophy was a higher age (P = 0.02). CONCLUSIONS: Leptin as measured in plasma is unlikely to play a major role in the genesis of lipoatrophy.

Mechanisms and drug therapy of pulmonary hypertension at high altitude

Pulmonary vasoconstriction represents a physiological adaptive mechanism to high altitude. If exaggerated, however, it is associated with important morbidity and mortality. Recent mechanistic studies using short-term acute high altitude exposure have provided insight into the importance of defective vascular endothelial and respiratory epithelial nitric oxide (NO) synthesis, increased endothelin-1 bioavailability, and overactivation of the sympathetic nervous system in causing exaggerated hypoxic pulmonary hypertension in humans. Based on these studies, drugs that increase NO bioavailability, attenuate endothelin-1 induced pulmonary vasoconstriction, or prevent exaggerated sympathetic activation have been shown to be useful for the treatment/prevention of exaggerated pulmonary hypertension during acute short-term high altitude exposure. The mechanisms underpinning chronic pulmonary hypertension in high altitude dwellers are less well understood, but recent evidence suggests that they differ in some aspects from those involved in short-term adaptation to high altitude. These differences have consequences for the choice of the treatment for chronic pulmonary hypertension at high altitude. Finally, recent data indicate that fetal programming of pulmonary vascular dysfunction in offspring of preeclampsia and children generated by assisted reproductive technologies represents a novel and frequent cause of pulmonary hypertension at high altitude. In animal models of fetal programming of hypoxic pulmonary hypertension, epigenetic mechanisms play a role, and targeting of these mechanisms with drugs lowers pulmonary artery pressure. If epigenetic mechanisms also are operational in the fetal programming of pulmonary vascular dysfunction in humans, such drugs may become novel tools for the treatment of hypoxic pulmonary hypertension.

ATM Signaling to TSC2: Mechanisms and Implications for Cancer Therapy

Ataxia telangiectasia mutated (ATM) is a critical component of the cellular response to DNA damage, where it acts as a damage sensor, and signals to a large network of proteins which execute the important tasks involved in responding to the damage, namely inducing cell cycle checkpoints, inducing DNA repair, modulating transcriptional responses, and regulating cell death pathways if the damage cannot be repaired faithfully. We have now discovered that an additional novel component of this ATM-dependent damage response involves induction of autophagy in response to oxidative stress. In contrast to DNA damage-induced ATM activation however, oxidative stress induced ATM, occurs in the cytoplasm, and does not require nuclear-to-cytoplasmic shuttling of ATM. Using several cell culture systems including MCF7 breast carcinoma cells, SKOV3 ovarian cancer cells, and various lineages of mouse embryonic fibroblasts, we showed that once activated by reactive oxygen species (ROS), ATM signals to mTORC1 to induce autophagy via the LKB1-AMPK-TSC2 pathway. Targeting dysregulation of mTORC1 in Atm-deficient mice, which succumb to lymphomagenesis within 3-4 months of age with daily administration of rapamycin, could significantly extend survival and cause regression of tumors, suggesting that pharmacologically targeting this pathway has therapeutic implications in cancer. We also identified a second contrasting pathway for DNA damage-induced mTORC1 repression which does not require AMPK activation, but does require ATM and TSC2. Several potential mechanisms including mTOR localization and p53-mediated pathways were ruled out however we identified that TSC2 may be an additional cytoplasmic direct ATM substrate that is engaged in response to DNA damage specifically. Lastly, a study was performed to examine whether autophagy induced by ovarian cancer therapeutics (focusing on cisplatin, since paclitaxel does not induce autophagy in the SKOV3 cell line model we used) plays a role in resistance to therapy since autophagy can play both pro-survival mechanisms or be a mechanism of cell death. Using a genetic approach to knock-down Atg5 expression with shRNA in SKOV3 ovarian carcinoma cells, we compared the cytotoxicity of cisplatin in vector or Atg5 knock-down cells, and demonstrated that autophagy does not play any significant role in the response to cisplatin in this cell line.

Gene therapy of cancer: Mechanisms of ``bystander effect'' killing in cells expressing the herpes simplex virus-thymidine kinase gene and its potential clinical applications

At the fore-front of cancer research, gene therapy offers the potential to either promote cell death or alter the behavior of tumor-cells. One example makes use of a toxic phenotype generated by the prodrug metabolizing gene, thymidine kinase (HSVtk) from the Herpes Simplex Virus. This gene confers selective toxicity to a relatively nontoxic prodrug, ganciclovir (GCV). Tumor cells transduced with the HSVtk gene are sensitive to 1-50 $\mu$M GCV; normal tissue is insensitive up to 150-250 $\mu$M GCV. Utilizing these different sensitivities, it is possible to selectively ablate tumor cells expressing this gene. Interestingly, if a HSVtk$\sp+$ expressing population is mixed with a HSVtk$\sp-$ population at high density, all the cells are killed after GCV administration. This phenomenon for killing all neighboring cells is termed the "bystander effect", which is well documented in HSVtk$\sp-$ GCV systems, though its exact mechanism of action is unclear.^ Using the mouse colon carcinoma cell line CT26, data are presented supporting possible mechanisms of "bystander effect" killing of neighboring CT26-tk$\sp-$cells. A major requirement for bystander killing is the prodrug GCV: as dead or dying CT26tk$\sp+$ cells have no toxic effect on neighboring cells in its absence. In vitro, it appears the bystander effect is due to transfer of toxic GCV-metabolites, through verapamil sensitive intracellular-junctions. Additionally, possible transfer of the HSVtk enzyme to bystander cells after GCV addition, may play a role in bystander killing. A nude mouse model suggests that in a 50/50 (tk$\sp+$/tk$\sp-$) mixture of CT26 cells the bystander eradication of tumors does not involve an immune component. Additionally in a possible clinical application, the "bystander effect" can be directly exploited to eradicate preexisting CT26 colon carcinomas in mice by intratumoral implantation of viable or lethally irradiated CT26tk$\sp+$ cells and subsequent GCV administration. Lastly, an application of this toxic phenotype gene to a clinical marking protocol utilizing a recombinant adenoviral vector carrying the bifunctional protein GAL-TEK to eradicate spontaneously-arisen or vaccine-induced fibrosarcomas in cats is demonstrated. ^

How nice is good for patients and for therapy outcome? The role of confrontation in the process of psychotherapy

It is well established that the therapeutic relationship contributes about as much to therapy outcome as 'technical' intervention. Furthermore, it follows clear prescriptive concepts in the same manner as technical interventions do. 'Motive Oriented Therapeutic Relationship' is such a concept for establishing a solid basis for whatever therapeutic work the patients' problems require (Grawe, 1980, 1992; Caspar, 1996). Yet, the therapeutic relationship doesn't explain everything because other factors play a significant role too. Previous studies showed that outcome is clearly better when therapists achieved a generally high quality of a therapeutic relationship when they did not shy away from possibly threatening interventions such as confrontations. This ratio of a fruitful alliance and marginally present confrontations in the same session also showed significant correlations with patient's assessment of alliance and progress in therapy (Figlioli et al., 2009).Aim: The current state of research in the field does not give any answers to questions like how good and bad confrontations can be characterized or what role does the intensity, respectively frequency of confrontations play in the process of psychotherapy. Methods: A sample of 80 therapies of 3 sessions each representing either good or bad outcome was judged moment by moment by independent raters if and how therapists used confrontative interventions. Results: Preliminary analyses show that successful confrontations are explicitly uttered, short but intense, related to important patients goals in therapy and embedded in prior complementarity. Discussion: The results will be discussed in terms of their implications for the clinical daily work.

How nice is good for patients and for therapy outcome? The role of confrontation in the process of psychotherapy

It is well established that the therapeutic relationship contributes about as much to therapy outcome as ‘technical’ intervention. Furthermore, it follows clear prescriptive concepts in the same manner as technical interventions do. ‘Motive Oriented Therapeutic Relationship’ is such a concept for establishing a solid basis for whatever therapeutic work the patients’ problems require (Grawe, 1980, 1992; Caspar, 1996). Yet, the therapeutic relationship doesn’t explain everything because other factors play a significant role too. Previous studies showed that outcome is clearly better when therapists achieved a generally high quality of a therapeutic relationship when they did not shy away from possibly threatening interventions such as confrontations. This ratio of a fruitful alliance and marginally present confrontations in the same session also showed significant correlations with patient’s assessment of alliance and progress in therapy (Figlioli et al., 2009). These findings are also very much in line with Sachse’s metaphor of accumulating, but then also using ‘relationship credits’ and Farrelly’s ‘Provocative Therapy’ (1986), as well as the ‘Intensive Short-Term Dynamic Psychotherapy’ by Davanloo (1980).Aim: The current state of research in the field does not give any answers to questions like how good and bad confrontations can be characterized or what role does the intensity, respectively frequency of confrontations play in the process of psychotherapy.Methods: A sample of 80 therapies of 3 sessions each representing either good or bad outcome was judged moment by moment by independent raters if and how therapists used confrontative interventions. Results / Discussion: The results will be discussed in terms of their implications for the clinical daily work. Preliminary analyses show that successful confrontations are explicitly uttered, short but intense, related to important patients goals in therapy and embedded in prior complementarity.

Don't forget asking the others! - The added value of significant other's reports on patient interpersonal style for the prediction of therapy process and outcome

Theory: Interpersonal factors play a major role in causing and maintaining depression. It is unclear, however, to what degree significant others of the patient need to be involved for characterizing the patient's interpersonal style. Therefore, our study sought to investigate how impact messages as perceived by the patients' significant others add to the prediction of psychotherapy process and outcome above and beyond routine assessments, and therapist factors. Method: 143 outpatients with major depressive disorder were treated by 24 therapists with CBT or Exposure-Based Cognitive Therapy. Interpersonal style was measured pre and post therapy with the informant‐based Impact Message Inventory (IMI), in addition to the self‐report Inventory of Interpersonal Problems (IIP‐32). Indicators for the patients' dominance and affiliation as well as interpersonal distress were calculated from these measures. Depressive and general symptomatology was assessed at pre, post, and at three months follow‐up, and by process measures after every session. Results: Whereas significant other's reports did not add significantly to the prediction of the early therapeutic alliance, central mechanisms of change, or post‐therapy outcome including therapist factors, the best predictor of outcome 3 months post therapy was an increase in dominance as perceived by significant others. Conclusions: The patients' significant others seem to provide important additional information about the patients' interpersonal style and therefore should be included in the diagnostic process. Moreover, practitioners should specifically target interpersonal change as a potential mechanism of change in psychotherapy for depression.

Periodontal and peri-implant wound healing following laser therapy

Laser irradiation has numerous favorable characteristics, such as ablation or vaporization, hemostasis, biostimulation (photobiomodulation) and microbial inhibition and destruction, which induce various beneficial therapeutic effects and biological responses. Therefore, the use of lasers is considered effective and suitable for treating a variety of inflammatory and infectious oral conditions. The CO2 , neodymium-doped yttrium-aluminium-garnet (Nd:YAG) and diode lasers have mainly been used for periodontal soft-tissue management. With development of the erbium-doped yttrium-aluminium-garnet (Er:YAG) and erbium, chromium-doped yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers, which can be applied not only on soft tissues but also on dental hard tissues, the application of lasers dramatically expanded from periodontal soft-tissue management to hard-tissue treatment. Currently, various periodontal tissues (such as gingiva, tooth roots and bone tissue), as well as titanium implant surfaces, can be treated with lasers, and a variety of dental laser systems are being employed for the management of periodontal and peri-implant diseases. In periodontics, mechanical therapy has conventionally been the mainstream of treatment; however, complete bacterial eradication and/or optimal wound healing may not be necessarily achieved with conventional mechanical therapy alone. Consequently, in addition to chemotherapy consisting of antibiotics and anti-inflammatory agents, phototherapy using lasers and light-emitting diodes has been gradually integrated with mechanical therapy to enhance subsequent wound healing by achieving thorough debridement, decontamination and tissue stimulation. With increasing evidence of benefits, therapies with low- and high-level lasers play an important role in wound healing/tissue regeneration in the treatment of periodontal and peri-implant diseases. This article discusses the outcomes of laser therapy in soft-tissue management, periodontal nonsurgical and surgical treatment, osseous surgery and peri-implant treatment, focusing on postoperative wound healing of periodontal and peri-implant tissues, based on scientific evidence from currently available basic and clinical studies, as well as on case reports.

Encouragement to Increase the Use of Psychosocial Skills in the Diagnosis and Therapy of Patients With Functional Dysphonia.

Clinicians believe that psychosocial factors play a causal role in the etiology of many forms of functional dysphonia (FD). But for decades, all attempts to confirm such causation have failed. This paper aims to show the logic of this failure, to discuss the possibilities of employing psychology in therapy nonetheless, and to encourage clinicians to use their psychosocial knowledge and skills. The failure to confirm psychic and social factors as causal in the etiology of FD is basically a consequence of a principal shortcoming of evidence-based medicine (EBM). As the gold standard for validity, reliability, and objectivity in medical research, EBM is based on calculability and hence the processing of quantitative data. But life paths and life situations are best or sometimes only expressible in qualitative, experiential, and idiographic terms. Thus EBM-guided evaluation undervalues most psychosocial studies. This report of an experienced multidisciplinary voice team proposes alternative pathways for integrating psychosocial knowledge into the diagnosis and the treatment of FD. The difference between the fields of activity of psychotherapists and speech-language pathologists is discussed, and the latter group is shown the potential benefits of using more of their psychosocial knowledge and skills.

Monte Carlo and analytical dose calculations for ocular proton therapy

Uveal melanoma is a rare but life-threatening form of ocular cancer. Contemporary treatment techniques include proton therapy, which enables conservation of the eye and its useful vision. Dose to the proximal structures is widely believed to play a role in treatment side effects, therefore, reliable dose estimates are required for properly evaluating the therapeutic value and complication risk of treatment plans. Unfortunately, current simplistic dose calculation algorithms can result in errors of up to 30% in the proximal region. In addition, they lack predictive methods for absolute dose per monitor unit (D/MU) values. ^ To facilitate more accurate dose predictions, a Monte Carlo model of an ocular proton nozzle was created and benchmarked against measured dose profiles to within ±3% or ±0.5 mm and D/MU values to within ±3%. The benchmarked Monte Carlo model was used to develop and validate a new broad beam dose algorithm that included the influence of edgescattered protons on the cross-field intensity profile, the effect of energy straggling in the distal portion of poly-energetic beams, and the proton fluence loss as a function of residual range. Generally, the analytical algorithm predicted relative dose distributions that were within ±3% or ±0.5 mm and absolute D/MU values that were within ±3% of Monte Carlo calculations. Slightly larger dose differences were observed at depths less than 7 mm, an effect attributed to the dose contributions of edge-scattered protons. Additional comparisons of Monte Carlo and broad beam dose predictions were made in a detailed eye model developed in this work, with generally similar findings. ^ Monte Carlo was shown to be an excellent predictor of the measured dose profiles and D/MU values and a valuable tool for developing and validating a broad beam dose algorithm for ocular proton therapy. The more detailed physics modeling by the Monte Carlo and broad beam dose algorithms represent an improvement in the accuracy of relative dose predictions over current techniques, and they provide absolute dose predictions. It is anticipated these improvements can be used to develop treatment strategies that reduce the incidence or severity of treatment complications by sparing normal tissue. ^

In vivo inhibition of rat stellate cell activation by soluble transforming growth factor β type II receptor: A potential new therapy for hepatic fibrosis

Transforming growth factor β (TGF-β) is a well characterized cytokine that appears to play a major role in directing the cellular response to injury, driving fibrogenesis, and, thus, potentially underlying the progression of chronic injury to fibrosis. In this study, we report the use of a novel TGF-β receptor antagonist to block fibrogenesis induced by ligation of the common bile duct in rats. The antagonist consisted of a chimeric IgG containing the extracellular portion of the TGF-β type II receptor. This “soluble receptor” was infused at the time of injury; in some experiments it was given at 4 days after injury, as a test of its ability to reverse fibrogenesis. The latter was assessed by expression of collagen, both as the mRNA in stellate cells isolated from control or injured liver and also by quantitative histochemistry of tissue sections. When the soluble receptor was administered at the time of injury, collagen I mRNA in stellate cells from the injured liver was 26% of that from animals receiving control IgG (P < 0.0002); when soluble receptor was given after injury induction, collagen I expression was 35% of that in control stellate cells (P < 0.0001). By quantitative histochemistry, hepatic fibrosis in treated animals was 55% of that in controls. We conclude that soluble TGF-β receptor is an effective inhibitor of experimental fibrogenesis in vivo and merits clinical evaluation as a novel agent for controlling hepatic fibrosis in chronic liver injury.