Abrogation of RAB27A expression transiently affects melanoma cell proliferation

The role of the small GTPase RAB27A as an essential melanosome trafficking regulator in melanocytes is well-accepted. A decade ago, RAB27A was identified as a tumor dependency gene that promotes melanoma cell proliferation. RAB27A has since been linked to another propeller of cancer progression: exosome secretion. We have recently demonstrated that RAB27A is overexpressed in a subset of melanomas. High RAB27A gene and protein expression correlate with poor prognosis in melanoma patients. Mechanistic investigations revealed that the generation of pro-invasive exosomes was RAB27A-dependent and, therefore, silencing RAB27A reduced melanoma cell invasion in vitro and in vivo. However, previous studies have implicated RAB27A to be involved in both proliferation and invasion of melanoma cells. Employing four human cell lines, stratified by RAB27A expression, and one RAB27A-high mouse cell line, we demonstrate in this study that the effects of abrogating RAB27A expression on proliferation are only temporary, in contrast to our previously reported persistent effects on tumor invasion and metastasis. Therefore, we assist in the dissection of the short-term effects of RAB27A knockdown on melanoma cell proliferation versus long-term effects on melanoma invasion and metastasis. We believe that our findings provide novel insights into the effects of RAB27A blockade.

RAB27A promotes melanoma cell invasion and metastasis via regulation of pro-invasive exosomes

Despite recent advances in targeted and immune-based therapies, advanced stage melanoma remains a clinical challenge with a poor prognosis. Understanding the genes and cellular processes that drive progression and metastasis is critical for identifying new therapeutic strategies. Here, we found that the GTPase RAB27A was overexpressed in a subset of melanomas, which correlated with poor patient survival. Loss of RAB27A expression in melanoma cell lines inhibited 3D spheroid invasion and cell motility in vitro, and spontaneous metastasis in vivo. The reduced invasion phenotype was rescued by RAB27A-replete exosomes, but not RAB27A-knockdown exosomes, indicating that RAB27A is responsible for the generation of pro-invasive exosomes. Furthermore, while RAB27A loss did not alter the number of exosomes secreted, it did change exosome size and altered the composition and abundance of exosomal proteins, some of which are known to regulate cancer cell movement. Our data suggest that RAB27A promotes the biogenesis of a distinct pro-invasive exosome population. These findings support RAB27A as a key cancer regulator, as well as a potential prognostic marker and therapeutic target in melanoma.

Abstract 5167: Rab27a promotes melanoma cell invasion and metastasis via the regulation of exosome secretion

Introduction: The Rab GTPase family has been increasingly related to carcinogenesis and cancer biology during the past decade. In melanoma, Rab27a has been identified as a tumor dependency gene. Rab27a is thought to regulate exosome secretion in several cell types, however the exact role of Rab27a in melanoma biology and the underlying mechanisms are not well investigated.

Experimental Procedures: To investigate the influence of Rab27a on melanoma biology and exosome secretion, Rab27a shRNA knockdown (KD) or CRISPR knockout (KO) was performed in human and murine melanoma cell lines. The effect of Rab27a loss on melanoma cell invasion and motility was analyzed by in vitro 3D spheroid invasion and live cell imaging. Rab27a function on melanoma metastasis was investigated using a mouse melanoma spontaneous metastasis model. Exosomes secreted by melanoma cell lines with/without Rab27a KD/KO were purified and characterized by electron microscopy, NanoSight analysis, BCA assay, western blotting and mass spectrometry.

Results: Our results indicate that Rab27a loss in Rab27a high metastatic melanoma cell lines reduced 3D spheroid invasion and cell motility and Rab27a loss also reduced spontaneous melanoma metastasis in vivo. Rab27a KD invasion phenotype can be partially rescued by addition of exosomes from Rab27a replete cell conditioned media, but not exosomes derived from Rab27a KD cells. Loss of Rab27a does not alter the number of exosomes secreted from melanoma cells, but does alter exosome protein composition and morphology. Mass spectrometry analysis has shown that Rab27a replete cell secreted exosomes are more involved in regulating cell invasion and motility than the exosomes from Rab27a KD cells.

Conclusion: In summary, Rab27a promotes the invasion and metastasis of a subset of melanoma cells via the regulation of pro-invasive exosomes, which indicates Rab27a as a potential therapeutic target for preventing melanoma progression.

Citation Format: DAJIANG GUO, Goldie Y. Lui, Danae M. Sharp, Siew Li Lai, Shweta Tikoo, Rain Kwan, Michelle van Geldermalsen, Jeff Holst, Nikolas K. Haass, Wolfgang Weninger, Kimberley A. Beaumont. Rab27a promotes melanoma cell invasion and metastasis via the regulation of exosome secretion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5167.

HDAC inhibitors restore BRAF-inhibitor sensitivity by altering PI3K and survival signalling in a subset of melanoma

Mutations in BRAF activate oncogenic MAPK signalling in almost half of cutaneous melanomas. Inhibitors of BRAF (BRAFi) and its target MEK are widely used to treat melanoma patients with BRAF mutations but unfortunately acquired resistance occurs in the majority of patients. Resistance results from mutations or non-genomic changes that either reactivate MAPK signalling or activate other pathways that provide alternate survival and growth signalling. Here, we show the histone deacetylase inhibitor (HDACi) panobinostat overcomes BRAFi resistance in melanoma, but this is dependent on the resistant cells showing a partial response to BRAFi treatment. Using patient- and in vivo-derived melanoma cell lines with acquired BRAFi resistance, we show that combined treatment with the BRAFi encorafenib and HDACi panobinostat in 2D and 3D culture systems synergistically induced caspase-dependent apoptotic cell death. Key changes induced by HDAC inhibition included decreased PI3K pathway activity associated with a reduction in the protein level of a number of receptor tyrosine kinases, and cell line dependent upregulation of pro-apoptotic BIM or NOXA together with reduced expression of anti-apoptotic proteins. Independent of these changes, panobinostat reduced c-Myc and pre-treatment of cells with siRNA against c-Myc reduced BRAFi/HDACi drug-induced cell death. These results suggest that a combination of HDAC and MAPK inhibitors may play a role in treatment of melanoma where the resistance mechanisms are due to activation of MAPK-independent pathways.

Cell Cycle Phase-Specific Drug Resistance as an Escape Mechanism of Melanoma Cells

The tumor microenvironment is characterized by cancer cell subpopulations with heterogeneous cell cycle profiles. For example, hypoxic tumor zones contain clusters of cancer cells that arrest in G1 phase. It is conceivable that neoplastic cells exhibit differential drug sensitivity based on their residence in specific cell cycle phases. In this study, we used two-dimensional and organotypic melanoma culture models in combination with fluorescent cell cycle indicators to investigate the effects of cell cycle phases on clinically used drugs. We demonstrate that G1-arrested melanoma cells, irrespective of the underlying cause mediating G1 arrest, are resistant to apoptosis induced by the proteasome inhibitor bortezomib or the alkylating agent temozolomide. In contrast, G1-arrested cells were more sensitive to mitogen-activated protein kinase pathway inhibitor-induced cell death. Of clinical relevance, pretreatment of melanoma cells with a mitogen-activated protein kinase pathway inhibitor, which induced G1 arrest, resulted in resistance to temozolomide or bortezomib. On the other hand, pretreatment with temozolomide, which induced G2 arrest, did not result in resistance to mitogen-activated protein kinase pathway inhibitors. In summary, we established a model to study the effects of the cell cycle on drug sensitivity. Cell cycle phase-specific drug resistance is an escape mechanism of melanoma cells that has implications on the choice and timing of drug combination therapies.

Targeting glutamine transport to suppress melanoma cell growth

Amino acids, especially leucine and glutamine, are important for tumor cell growth, survival and metabolism. A range of different transporters deliver each specific amino acid into cells, some of which are increased in cancer. These amino acids consequently activate the mTORC1 pathway and drive cell cycle progression. The leucine transporter LAT1/4F2hc heterodimer assembles as part of a large complex with the glutamine transporter ASCT2 to transport amino acids. In this study, we show that the expression of LAT1 and ASCT2 is significantly increased in human melanoma samples and is present in both BRAF(WT) (C8161 and WM852) and BRAF(V600E) mutant (1205Lu and 451Lu) melanoma cell lines. While inhibition of LAT1 by BCH did not suppress melanoma cell growth, the ASCT2 inhibitor BenSer significantly reduced both leucine and glutamine transport in melanoma cells, leading to inhibition of mTORC1 signaling. Cell proliferation and cell cycle progression were significantly reduced in the presence of BenSer in melanoma cells in 2D and 3D cell culture. This included reduced expression of the cell cycle regulators CDK1 and UBE2C. The importance of ASCT2 expression in melanoma was confirmed by shRNA knockdown, which inhibited glutamine uptake, mTORC1 signaling and cell proliferation. Taken together, our study demonstrates that ASCT2-mediated glutamine transport is a potential therapeutic target for both BRAF(WT) and BRAF(V600E) melanoma.

P-glycoprotein mediates drug resistance via a novel mechanism involving lysosomal sequestration

Localization of the drug transporter P-glycoprotein (Pgp) to the plasma membrane is thought to be the only contributor of Pgp-mediated multidrug resistance (MDR). However, very little work has focused on the contribution of Pgp expressed in intracellular organelles to drug resistance. This investigation describes an additional mechanism for understanding how lysosomal Pgp contributes to MDR. These studies were performed using Pgp-expressing MDR cells and their non-resistant counterparts. Using confocal microscopy and lysosomal fractionation, we demonstrated that intracellular Pgp was localized to LAMP2-stained lysosomes. In Pgp-expressing cells, the Pgp substrate doxorubicin (DOX) became sequestered in LAMP2-stained lysosomes, but this was not observed in non-Pgp-expressing cells. Moreover, lysosomal Pgp was demonstrated to be functional because DOX accumulation in this organelle was prevented upon incubation with the established Pgp inhibitors valspodar or elacridar or by silencing Pgp expression with siRNA. Importantly, to elicit drug resistance via lysosomes, the cytotoxic chemotherapeutics (e.g. DOX, daunorubicin, or vinblastine) were required to be Pgp substrates and also ionized at lysosomal pH (pH 5), resulting in them being sequestered and trapped in lysosomes. This property was demonstrated using lysosomotropic weak bases (NH4Cl, chloroquine, or methylamine) that increased lysosomal pH and sensitized only Pgp-expressing cells to such cytotoxic drugs. Consequently, a lysosomal Pgp-mediated mechanism of MDR was not found for non-ionizable Pgp substrates (e.g. colchicine or paclitaxel) or ionizable non-Pgp substrates (e.g. cisplatin or carboplatin). Together, these studies reveal a new mechanism where Pgp-mediated lysosomal sequestration of chemotherapeutics leads to MDR that is amenable to therapeutic exploitation.

The iron chelator, deferasirox, as a novel strategy for cancer treatment: oral activity against human lung tumor xenografts and molecular mechanism of action

Deferasirox is an orally effective iron (Fe) chelator currently used for the treatment of iron-overload disease and has been implemented as an alternative to the gold standard chelator, desferrioxamine (DFO). Earlier studies demonstrated that DFO exhibits anticancer activity due to its ability to deplete cancer cells of iron. In this investigation, we examined the in vitro and in vivo activity of deferasirox against cells from human solid tumors. To date, there have been no studies to investigate the effect of deferasirox on these types of tumors in vivo. Deferasirox demonstrated similar activity at inhibiting proliferation of DMS-53 lung carcinoma and SK-N-MC neuroepithelioma cell lines compared with DFO. Furthermore, deferasirox was generally similar or slightly more effective than DFO at mobilizing cellular (59)Fe and inhibiting iron uptake from human transferrin depending on the cell type. However, deferasirox potently inhibited DMS-53 xenograft growth in nude mice when given by oral gavage, with no marked alterations in normal tissue histology. To understand the antitumor activity of deferasirox, we investigated its effect on the expression of molecules that play key roles in metastasis, cell cycle control, and apoptosis. We demonstrated that deferasirox increased expression of the metastasis suppressor protein N-myc downstream-regulated gene 1 and upregulated the cyclin-dependent kinase inhibitor p21(CIP1/WAF1) while decreasing cyclin D1 levels. Moreover, this agent increased the expression of apoptosis markers, including cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase 1. Collectively, we demonstrate that deferasirox is an orally effective antitumor agent against solid tumors.

Novel second-generation di-2-pyridylketone thiosemicarbazones show synergism with standard chemotherapeutics and demonstrate potent activity against lung cancer xenografts after oral and intravenous administration in vivo

We developed a series of second-generation di-2-pyridyl ketone thiosemicarbazone (DpT) and 2-benzoylpyridine thiosemicarbazone (BpT) ligands to improve the efficacy and safety profile of these potential antitumor agents. Two novel DpT analogues, Dp4e4mT and DpC, exhibited pronounced and selective activity against human lung cancer xenografts in vivo via the intravenous and oral routes. Importantly, these analogues did not induce the cardiotoxicity observed at high nonoptimal doses of the first-generation DpT analogue, Dp44mT. The Cu(II) complexes of these ligands exhibited potent antiproliferative activity having redox potentials in a range accessible to biological reductants. The activity of the copper complexes of Dp4e4mT and DpC against lung cancer cells was synergistic in combination with gemcitabine or cisplatin. It was demonstrated by EPR spectroscopy that dimeric copper compounds of the type [CuLCl](2), identified crystallographically, dissociate in solution to give monomeric 1:1 Cu:ligand complexes. These monomers represent the biologically active form of the complex.

Stress and burnout among colorectal surgeons and colorectal nurse specialists working in the National Health Service

BACKGROUND

It has been suggested that changes to the organization of the National Health Service (NHS) and clinical practices in dealing with cancer are associated with increased stress and burnout in healthcare professionals. The aim of this study, therefore, was to evaluate stress and burnout in colorectal surgeons (surgeons) and colorectal clinical nurse specialists (nurses) working in the NHS.

METHOD

A list of all consultant surgeons and nurses was obtained from The Association of Coloproctology of Great Britain and Ireland. Participants were sent a questionnaire booklet consisting of standardized measures [General Health Questionnaire (GHQ), Maslach Burnout Inventory (MBI), Coping Questionnaire] and various ad hoc questions to obtain information about demographics, cancer workload and job satisfaction. Independent predictors of clinically significant distress and burnout were identified using logistic regression.

RESULTS

Four hundred and fifty-five surgeons and 326 nurses were sent booklets. The response rate was 55.6% in surgeons and 54.3% in nurses. The mean age of the nurses was lower than that of surgeons (42.8 vs 47.7, P < 0.001). Psychiatric morbidity was similar in the surgeons and nurses as assessed using the GHQ (30.2% and 30.3% respectively). On the MBI, compared with nurses, surgeons had significantly higher levels of depersonalization (17.4%vs 7.4%, P = 0.003) and lower personal accomplishment (26.6%vs 14.2%, P = 0.002). Seventy-seven per cent of surgeons and 63.4% of nurses stated their intention to retire before the statutory retirement age. Coping strategies, especially those in which respondents isolated themselves from friends and family, were associated with higher psychiatric morbidity and burnout. Dissatisfaction with work, intention to retire early, intention to retire as soon as affordable and poor training in communication and management skills were also significantly associated with high GHQ scores and burnout in both groups.

DISCUSSION

We found high levels of psychiatric morbidity and burnout in this national cohort of surgeons and nurses working in the NHS. However, psychiatric morbidity and burnout were unrelated to cancer workload. Nurses have lower burnout levels than surgeons and this may be related to their different working practices, responsibilities and management structure.

Vascular endothelial growth factor and psychosocial factors in colorectal cancer

BACKGROUND

Vascular endothelial growth factor (VEGF) and psychosocial factors have both been shown to have independent prognostic value in colorectal cancer. Recently, an association between VEGF and psychosocial factors has been reported in patients with ovarian cancer.

METHODS

A consecutive series of eligible patients undergoing elective resection for colorectal cancer were invited to participate. Standardized measures of various aspects of quality of life (QoL) were administered 5-12 days before surgery, and again 6-8 weeks after the operation, blood samples were obtained at the same times. Solid phase ELISA was used for VEGF-A analysis using serum samples. Correlations and multiple regression analysis were used to examine the relationship between VEGF and psychosocial factors.

RESULTS

One hundred and four patients with colorectal cancer were recruited. Seventy (67%) were male and the mean age was 67.6 years.A significant positive correlation was found between preoperative VEGF level and preoperative depression (r=0.227, p=0.03). Preoperative VEGF was negatively correlated with preoperative cancer-related concerns (r=-0.273, p=0.009) and positive affectivity (r=-0.219, p=0.05). Linear regression using TNM stage as a covariate showed that cancer-related concerns were an independent predictor of preoperative VEGF levels (p=0.02). Preoperative cancer-related concerns and global QoL were negatively correlated with postoperative VEGF (r=-0.381, p=0.001, r=-0.264, p=0.005), whereas preoperative depression correlated positively with postoperative VEGF (r=0.333, p=0.003). Linear regression analysis showed that preoperative HADS depression (p=0.005) and cancer-related concerns (p=0.002) were independent predictors of postoperative VEGF levels. Postoperative VEGF was significantly correlated with postoperative anxiety (r=0.249, p=0.02), depression (r=0.289, p=0.01), and functional well-being (r=-0.242, p=0.03). Linear regression analysis showed that postoperative anxiety (p=0.048), depression (p=0.013) and functional well-being (p=0.046) independently predicted postoperative VEGF-A levels.

CONCLUSION

Various psychosocial factors, particularly cancer-related concerns and depression, appear to be related to preoperative and postoperative VEGF level in patients with newly diagnosed colorectal cancer. However, the clinical significance of these findings needs to be addressed in longitudinal follow-up studies of recurrence and survival. Future prognostic studies involving VEGF and related cytokines should assess psychosocial variables at various time points and include these in a multivariate analysis of outcomes.

Patient personality predicts postoperative stay after colorectal cancer resection

OBJECTIVE

Postoperative length of stay (LOS) is an important outcome after colorectal cancer surgery. The aim of this study was to evaluate the putative effects of personality, mood, coping and quality of life on LOS.

METHOD

A consecutive series of 110 eligible patients undergoing elective resection for colorectal cancer were invited to participate in the study. A battery of psychometric questionnaires including the Hospital Anxiety and Depression Scale, the Functional Assessment of Cancer Therapy (colorectal), the Courtauld Emotional Control Scale, the Positive and Negative Affectivity Scale and the Eysenck Personality Questionnaire (EPQ) were administered 5-12 days before surgery. Nonparametric correlations were computed for psychometric scores, demographic variables and the LOS. Factors found to be significantly correlated on this analysis were entered into a multiple regression model to determine the independent predictors of LOS.

RESULTS

One hundred and four patients with colorectal cancer participated. Seventy were male (67%) and the mean age was 68 years (range 39-86). The median LOS was 10 days (range 4-108). LOS was negatively correlated with pre- and postoperative albumin levels, PANAS +ve affect, Functional Assessment of Cancer Therapy questionnaire with the colorectal module functional well-being score and EPQ extroversion score. LOS was strongly positively correlated with postoperative morbidity. LOS was positively correlated with CECS anger score, age and being male. Postoperative morbidity (beta = 0.379, P = 0.007) and extroversion (beta = -0.318, P = 0.05) were independent predictors of LOS.

CONCLUSION

Personality as measured by EPQ predicts postoperative LOS in patients with colorectal cancer. Extroverts have a higher pain threshold and this may be part of the explanation.

Colorectal MDTs: the team's perspective

OBJECTIVE

Multidisciplinary teams (MDTs) are an integral part of the National Cancer Plan. However, there is surprisingly little empirical research on how these are perceived by colorectal surgeons (CRSs) and colorectal clinical nurse specialists (CNSs). The purpose of this study therefore was to obtain the views of a national cohort of CRSs and CNSs regarding various important aspects of MDT functioning and role of CNS in current setting.

METHOD

Two hundred and fifty-three CRSs and 177 CNSs, identified from the Association of Coloproctologists of Great Britain and Ireland, responded to an ad hoc postal questionnaire.

RESULTS

96.5% of respondents considered that MDTs improved the overall quality of care of colorectal cancer patients, and 78.6% thought MDTs were good for their morale. Eighty per cent considered that they improved training. Seventy-three per cent of surgeons and nurses thought that MDTs were cost effective, and 89% did not consider them to be a passing fad. However, more than half (50.4%) of the CRSs and 35.2% of the CNSs stated that their job plan did not contain adequate time to attend MDT meetings. Compared with CRSs, CNSs were significantly more likely to have positive views regarding the MDT (P < 0.005).

CONCLUSION

CNSs and CRSs consider that colorectal MDTs have very beneficial effects on patient care, training and morale. However, many surgeons and nurse specialists consider that attendance at MDTs is not taken into account adequately in terms of their job plans, and this issue needs to be addressed.

Predictors of Early Postoperative Quality of Life after Elective Resection for Colorectal Cancer

INTRODUCTION

Measurement of quality of life (QoL) is assuming increasing importance in cancer care. Predictors of early postoperative QoL after colorectal cancer resection are not clear and the aim of this study was to identify these factors.

METHODS

A consecutive series of eligible patients undergoing elective resection for colorectal cancer were invited to participate. Standardised, reliable and validated psychological questionnaires (HADS, PANAS, MRS, FACT-C, EQ-5D) were administered seven days prior to surgery and then six weeks after discharge.

RESULTS

One hundred and four patients with colorectal cancer were recruited. There were 70 males (67.3%) and the mean age of the group was 67.6 years. Postoperative anxiety and depression were closely related to the preoperative anxiety and depression scores (p < 0.001). Other QoL scores also showed significant correlation with the respective preoperative scores. Anxiety, depression, and FACT functional wellbeing scores were also correlated with the incidence of postoperative morbidity. On multiple regression analysis postoperative morbidity, tumour node metastasis (TNM) stage, presence of stoma and preoperative QoL scores were found to independently predict postoperative QoL scores.

CONCLUSION

Routine preoperative QoL measurement in cancer patients can identify patients at risk of having a poor QoL postoperatively. Suitable psychological and pharmaceutical intervention can be planned in advance for this group.

Retinal lead toxicity

A 35-year-old female who had suffered from acute lead poisoning when she was 22 years old, presented 13 years later with loss of vision in the right eye and normal vision in the left eye. She had a pale disc, narrowed arterioles and mid-peripheral heavy pigmentation, right eye being more affected than the left eye. Electrodiagnostic tests identified marked asymmetry of visual function. We would postulate lead retinal toxicity as the cause of the asymmetric findings.

Long-term outcome of cognitive behaviour therapy clinical trials in central Scotland

OBJECTIVES

To establish the long-term outcome of participants in clinical trials of cognitive behaviour therapy (CBT) for anxiety disorders and psychosis, examining the effectiveness and cost-effectiveness associated with receiving CBT in comparison with alternative treatments.

DESIGN

An attempt was made to contact and interview all of the participants in eight randomised, controlled, clinical trials of CBT for anxiety disorders and two randomised, controlled, clinical trials of CBT for schizophrenia conducted between 1985 and 2001. Case note reviews of healthcare resources used in the 2 years prior to entering the trials and the 2 years prior to follow-up interview were undertaken.

SETTING

Mixed rural and urban settings in five localities in central Scotland. Anxiety disorder trials were conducted mainly in primary care and included three with generalised anxiety disorder, four with panic disorder and one with post-traumatic stress disorder (PTSD). The psychosis studies (one on relapse prevention and one with chronic disorder) were conducted in secondary care.

PARTICIPANTS

Of the 1071 entrants to the 10 studies, 489 agreed to participate (46% of original entrants, 52% of those available to contact).

INTERVENTIONS

Follow-up interviews took place between 1999 and 2003, 2-14 years after the original treatment. Interviews for Trials 1-8 were conducted by a research psychologist blind to original treatment condition. Interviews for Trials 9 and 10 were conducted by community psychiatric nurses also blind to treatment condition. Case note reviews were completed following the interview.

MAIN OUTCOME MEASURES

For Trials 1-8 the main interview-based outcome measures were: Anxiety Disorders Interview Schedule-DSM-IV for diagnosis and co-morbidity, Clinical Global Severity (0-8) and the Hamilton Anxiety Rating Scale. The main patient-rated measures were: Brief Symptom Inventory, SF-36 II, Clinical Global Improvement (1-7), and the Positive and Negative Affect Scale. For Trials 9 and 10 the primary outcome measure was the interview-based Positive and Negative Syndrome Scale (PANSS).

RESULTS

For the anxiety disorder studies (Trials 1-8), over half of the participants (52%) had at least one diagnosis at long-term follow-up, with significant levels of co-morbidity and health status scores comparable to the lowest 10% of the general population. Only 36% reported receiving no interim treatment for anxiety over the follow-up period with 19% receiving almost constant treatment. Patients with PTSD did particularly poorly. There was a 40% real increase in healthcare costs over the two time periods, mainly due to an increase in prescribing. A close relationship was found between poor mental and physical health for those with a chronic anxiety disorder. Treatment with CBT was associated with a better long-term outcome than non-CBT in terms of overall symptom severity but not with regard to diagnostic status. The positive effects of CBT found in the original trials were eroded over longer time periods. No evidence was found for an association between more intensive therapy and more enduring effects of CBT. Long-term outcome was found to be most strongly predicted by the complexity and severity of presenting problems at the time of referral, by completion of treatment irrespective of modality and by the amount of interim treatment during the follow-up period. The quality of the therapeutic alliance, measured in two of the studies, was not related to long-term outcome but was related to short-term outcome. The cost-effectiveness analysis showed no advantages of CBT over non-CBT. The cost of providing CBT in the original trials was only a very small proportion (6.4%) of the overall costs of healthcare for this population, which are high for both physical and mental health problems. In the psychosis studies (Trials 9 and 10), outcome was generally poor with only 10% achieving a 25% reduction in total PANSS scores from pretreatment to long-term follow-up, also cost-effectiveness analysis showed no advantages of CBT over non-CBT, although healthcare costs fell over the two time periods mainly owing to a reduction in inpatient costs.

CONCLUSIONS

Psychological therapy services need to recognise that anxiety disorders tend to follow a chronic course and that good outcomes with CBT over the short term are no guarantee of good outcomes over the longer term. Clinicians who go beyond standard treatment protocols of about 10 sessions over a 6-month period are unlikely to bring about greater improvement. Poor outcomes over the long term are related to greater complexity and severity of presenting problems at the time of referral, failure to complete treatment irrespective of modality and the amount of interim treatment during the follow-up period. The relative gains of CBT are greater in anxiety disorders than in psychosis. Longitudinal research designs over extended periods of time (2-5 years), with large numbers of participants (500+), are required to investigate the relative importance of patient characteristics, therapeutic alliance and therapist expertise in determining the cost-effectiveness of CBT in the longer term.

Identification of selective inhibitors of cyclin dependent kinase 4

A new structural type of kinase inhibitor, containing a benzocarbazole nucleus, has been identified. Members of the series are selective for inhibition of the cyclin dependent kinase family of enzymes. Although the cdks are highly homologous, representatives of the series showed intra-cdk selectivities, especially for cdk4. SAR studies elucidated the important features of the molecules for inhibition.

Reducing therapist contact in cognitive behaviour therapy for panic disorder and agoraphobia in primary care: global measures of outcome in a randomised controlled trial

BACKGROUND

Panic disorder, with and without agoraphobia, is a prevalent condition presenting in general practice. Psychological treatments are effective but are limited by restricted availability. Interest has grown in methods by which the efficiency and thus availability of psychological treatments can be improved, with particular emphasis on reduced therapist contact formats.

AIM

To evaluate the relative efficacy in a primary care setting of a cognitive behaviour therapy (CBT) delivered at three levels of therapist contact: standard contact, minimum contact, and bibliotherapy.

METHOD

A total of 104 patients were randomly allocated to receive standard therapist contact, minimum therapist contact or bibliotherapy, with 91 patients completing treatment. All patients received an identical treatment manual and were seen by the same psychologist therapist. Outcome was reported in terms of brief global ratings of severity of illness, change in symptoms, and levels of social disruption. These brief measures were chosen to be suitable for use in general practice and were used at treatment entry and endpoint.

RESULTS

The standard therapist contact group had the strongest and most comprehensive treatment response, showing significant differences from the bibliotherapy group on all, and the minimum therapist contact group on some, endpoint measures. Some reduction in efficacy was therefore found for the reduced therapist contact groups.

CONCLUSION

The standard therapist contact group showed the greatest treatment efficacy in the present study. As it was of notably shorter duration than many other current formulations of CBT, it represents a useful and efficient treatment for panic disorder and agoraphobia in primary care.

Analysis of site-specific phosphorylation of the retinoblastoma protein during cell cycle progression

Differential phosphorylation of the retinoblastoma protein plays a pivotal role in cell cycle regulation. The retinoblastoma protein is specifically phosphorylated during the cell cycle by cyclin-dependent kinase complexes which intersect with many cellular signaling networks. Since the loss of the retinoblastoma signaling pathways occurs in a wide variety of human tumors, understanding the significance of site-specific phosphorylation can clarify the role of selected cyclin-dependent kinase complexes during cell cycle progression. Here we describe the phosphospecificity and cellular characterization of a panel of polyclonal antibodies that recognize unique phosphorylation sites within the retinoblastoma protein. These reagents were used to validate authentic cellular retinoblastoma phosphorylation sites at amino acids 780, 795, and 807/811 correlating with the G1-S transition.

Treatment-outcome research in panic disorder: dilemmas in reconciling the demands of pharmacological and psychological methodologies

Panic disorder with or without agoraphobia has been the subject of sustained treatment-outcome research. Studies have been conducted by both pharmacologically- and psychologically-oriented researchers each employing their own methodologies. Problems arise in attempting to reconcile the demands of these two treatment-outcome methodologies, whilst at the same time ensuring that research designs reflect the reality of wider clinical practice. In the following discussion a series of studies comparing pharmacological and psychological treatments for panic disorder and agoraphobia are reviewed. The review highlights areas where the competing demands of research design and clinical applicability lead to dilemmas for the researcher. Attempts to overcome such dilemmas are described and alternative solutions discussed.

Global measures of outcome in a controlled comparison of pharmacological and psychological treatment of panic disorder and agoraphobia in primary care

BACKGROUND

Panic disorder, with and without agoraphobia, is a prevalent condition which presents primarily in general practice. Previous clinical outcome studies have been conducted mainly in specialist university departments or hospital settings, and have tended to employ complex rating scales that are not well suited for use as outcome measures in primary care.

AIM

To evaluate the outcome, in a primary care setting, of fluvoxamine versus cognitive behaviour therapy, each used alone and in combination in a double-blind placebo-controlled framework, balanced for therapist contact.

METHOD

A total of 149 patients satisfying DSMIII-R criteria for panic disorder were randomly allocated to receive one of the following: fluvoxamine, placebo, fluvoxamine plus cognitive behaviour therapy, placebo plus cognitive behaviour therapy, and cognitive behaviour therapy alone. These five treatment groups represent the minimum number acceptable for such a comparison to be made. All patients received an identical schedule of contact over 13 weeks. Measures of symptom severity, general health and social disruption were taken at entry point and end point; measures of change in symptoms were taken at end point only. Outcome was reported in terms of brief global ratings of severity of illness and change in symptoms, and of ratings of general health and social disruption that are suitable for use in general practice.

RESULTS

All active treatment groups showed statistically significant advantages over placebo over a range of outcome ratings. The groups employing cognitive behaviour therapy showed the most robust and consistent response.

CONCLUSION

The brief global measures reported here proved adequate to the task of assessing treatment outcome. Results indicate that treatments including cognitive behaviour therapy can be effective in the treatment of panic disorder and agoraphobia in primary care.

Controlled comparison of the characteristics of patients with panic disorder

BACKGROUND

Increased general practice attendance rates have been associated with the diagnosis of mental illness but panic disorder has not been specifically investigated in this respect. In addition, studies have failed adequately to assess type and frequency of secondary care referral and patterns of psychotropic prescription in patients with panic disorder in relation to matched controls.

AIM

This study set out to compare subjects with panic disorder with age and sex matched controls on measures of general practice consultation rate; psychotropic and non-psychotropic drug use; referral to secondary care, laboratory and radiological tests and hospital admissions; history of illness and complaints; and psychiatric comorbidity.

METHOD

The study was carried out in nine practices in the Forth Valley area. One hundred patients with panic disorder, previously diagnosed using DSM III-R criteria, were identified and matched by age and sex with controls. Data were collected by review of general practice case notes.

RESULTS

Subjects with panic disorder had significantly higher rates of general practice consultation over the 10 year period prior to DSM III-R diagnosis of panic disorder than controls. Subjects with panic disorder had also been prescribed a significantly greater number of psychotropic and non-psychotropic medications over this period, had had more secondary care investigations and had higher rates of mainly minor illness and related complaints than controls. High comorbidity of panic disorder with depression which had been diagnosed over the 10 year period prior to DSM III-R diagnosis of panic disorder was found.

CONCLUSION

The results of this study describe a population of subjects with panic disorder who are long-term heavy users of primary care services. The results also suggest an association between panic disorder and both minor illness and psychiatric comorbidity over the 10 year period prior to DSM III-R diagnosis of panic disorder.

Linkage analysis in X-linked congenital stationary night blindness

X-linked congenital stationary night blindness (XL-CSNB) is a nonprogressive disorder of the retina, characterized by night blindness, reduced visual acuity, and myopia. Previous studies have localized the CSNB1 locus to the region between OTC and TIMP on the short arm of the X chromosome. We have carried out linkage studies in three XL-CSNB families that could not be classified as either complete or incomplete CSNB on the criteria suggested by Miyake et al. (1986. Arch. Ophthalmol. 104: 1013-1020). We used markers for the DXS538, DMD, OTC, MAOA, DXS426, and TIMP loci. Two-point analyses show that there is close linkage between CSNB and MAOA (theta max = 0.05, Zmax = 3.39), DXS426 (theta max = 0.06, Zmax = 2.42), and TIMP (theta max = 0.07, Zmax = 2.04). Two multiply informative crossovers are consistent with CSNB lying proximal to MAOA and distal to DXS426, respectively. Multipoint analysis supports this localization, giving the most likely order as DMD-17 cM-MAOA-7.5 cM-CSNB-7.5 cM-DXS426/TIMP-cen, and thus refines the localization of CSNB.

Retinal dysfunction in central serous retinopathy

Patients with acute and chronic central serous retinopathy (CSR) were studied by psychophysical and photochemical means to establish the extent of visual depression and to investigate the basis of rod dysfunction in this disorder. In acute disease with serous detachment of the retina, the loss of sensitivity attains 3 log units and parallels the height of retinal elevation as does its recovery with resolution of the episode. Immediately after resolution, there is a residual 0.5 log unit threshold elevation. In chronic disease, marked loss of function exists over areas of abnormal retinal pigment epithelium in the absence of clinically detectable serous detachment. Although rhodopsin levels are low in both acute and chronic CSR, this relative lack of visual pigment does not totally account for the functional deficits in either situation.

Stimulation by cyclic GMP of sodium efflux in barnacle muscle fibres

1. The ouabain-insensitive Na efflux in barnacle muscle fibres is promptly stimulated by injection of cyclic GMP. The minimal effective injected concentration is found to be about 10(-7) M. This effect of cyclic GMP could not be mimicked by injecting 5'-GMP. 2. External application of ouabain (10(-4) M) to fibres not pretreated with ouabain during the stimulatory response to cyclic GMP causes some inhibition of the Na efflux indicating that cyclic GMP does not cause appreciable inhibition of the Na:K pump. 3. The magnitude of the stimulatory response to injected cyclic GMP depends on the external Ca2+ concentration, as well as pHe but not on the Na+, K+ or Mg2+ concentration. It also depends on pHi, since acidification of HCO3-containing ASW leads to a greater enhancement of the response to cyclic GMP than is observed with acidified HERPES-ASW. 4. Stabilization of myoplasmic pCa by injecting 100 mM-EGTA before or after cyclic GMP fails to alter the magnitude of the response to the nucleotide. Enrichment of the fibre with Mg2+ at the time of injection of cyclic GMP leads to a reduced response. No change in response, however, is seen when the internal free Mg concentration is suddenly reduced by injecting 0.05 M-pyrophosphate with cyclic GMP. 5. Injection of cyclic GMP-dependent protein kinase stimulatory modulator before cyclic GMP fails to enhance the response to the nucleotide. The same is true of the phosphodiesterase inhibitor protein. However pre-injection of 10(-2) M-papaverine enhances the response to a subsequent injection of 10(-3) M-cyclic GMP. 6. Injection of pure protein kinase inhibitor (1.6 x 10(-4) M) before 10(-3) M-cyclic GMP reduces the response to the nucleotide. 7. The argument is put forward that injected cyclic GMP stimulates the ouabain-insensitive Na efflux mainly by activating cyclic AMP-protein kinase rather than cyclic GMP-proton kinase.