Acquired resistance to PRMT5 inhibition induces concomitant collateral sensitivity to paclitaxel.

Epigenetic regulators play key roles in cancer and are increasingly being targeted for treatment. However, for many, little is known about mechanisms of resistance to the inhibition of these regulators. We have generated a model of resistance to inhibitors of protein arginine methyltransferase 5 (PRMT5). This study was conducted in KrasG12D;Tp53-null lung adenocarcinoma (LUAD) cell lines. Resistance to PRMT5 inhibitors (PRMT5i) arose rapidly, and barcoding experiments showed that this resulted from a drug-induced transcriptional state switch, not selection of a preexisting population. This resistant state is both stable and conserved across variants arising from distinct LUAD lines. Moreover, it brought with it vulnerabilities to other chemotherapeutics, especially the taxane paclitaxel. This paclitaxel sensitivity depended on the presence of stathmin 2 (STMN2), a microtubule regulator that is specifically expressed in the resistant state. Remarkably, STMN2 was also essential for resistance to PRMT5 inhibition. Thus, a single gene is required for both acquisition of resistance to PRMT5i and collateral sensitivity to paclitaxel in our LUAD cells. Accordingly, the combination of PRMT5i and paclitaxel yielded potent and synergistic killing of the murine LUAD cells. Importantly, the synergy between PRMT5i and paclitaxel also extended to human cancer cell lines. Finally, analysis of The Cancer Genome Atlas patient data showed that high STMN2 levels correlate with complete regression of tumors in response to taxane treatment. Collectively, this study reveals a recurring mechanism of PRMT5i resistance in LUAD and identifies collateral sensitivities that have potential clinical relevance.

Stapled Peptides with γ-Methylated Hydrocarbon Chains for the Estrogen Receptor/Coactivator Interaction.

"Stapled" peptides are typically designed to replace two non-interacting residues with a constraining, olefinic staple. To mimic interacting leucine and isoleucine residues, we have created new amino acids that incorporate a methyl group in the γ-position of the stapling amino acid S5. We have incorporated them into a sequence derived from steroid receptor coactivator 2, which interacts with estrogen receptor α. The best peptide (IC50 =89 nm) replaces isoleucine 689 with an S-γ-methyl stapled amino acid, and has significantly higher affinity than unsubstituted peptides (390 and 760 nm). Through X-ray crystallography and molecular dynamics studies, we show that the conformation taken up by the S-γ-methyl peptide minimizes the syn-pentane interactions between the α- and γ-methyl groups.

Health Literacy Influences Men's Active and Passive Cancer Information Seeking.

BACKGROUND: For cancer prevention information to be effective, it must be accessible to its target populations. Prevalence of inadequate health literacy (HL) is high, but there is a dearth of information on the impact of HL on men's cancer information seeking. OBJECTIVE: We investigated (1) men's cancer information seeking behaviors, (2) the effect of HL on men's cancer information seeking behavior, and (3) men's preferences for cancer information, considering their HL level. From a national perspective, we investigated men's information seeking behavior from the Irish Cancer Society (ICS), the largest provider of cancer information in Ireland. METHODS: Men from adult literacy classes and men's groups were invited to complete a questionnaire. General and ICS-specific cancer information seeking behavior was investigated. Univariate and multivariate logistic regression models were conducted with "ever" seeking cancer information from any source, and actively seeking and passively acquiring ICS information as dependent variables. KEY RESULTS: Overall, 259 men completed the questionnaire and 44% had inadequate HL. About one-half of responders reported "ever" actively looking for cancer information. In the study group, 19% actively sought and 67% passively acquired ICS-specific information. In multivariate analysis, the odds of actively seeking (2.93; 95% CI [1.05, 8.15]) or passively acquiring (4.7; 95% CI [1.99, 11.05]) ICS-specific cancer information was significantly higher among those with adequate versus inadequate HL, respectively. HL was not significantly associated with odds of "ever" cancer information seeking in multivariate analysis (odds ratio 1.81; 95% CI [0.90, 3.63]). Men want information about cancer prevention. Suggested future cancer information sources differed by HL levels. General practitioners and the Internet were the preferred source for men with inadequate (53.3%) and adequate HL (57%), respectively. CONCLUSIONS: Men both passively acquire and actively seek cancer prevention information. Multimodal dissemination of cancer prevention information is necessary to reach a wide cross-section of men, including those with inadequate HL. This could potentially lower men's cancer burden and reduce gender inequalities in cancer mortality. [HLRP: Health Literacy Research and Practice. 2019;3(3):e147-e160.]. PLAIN LANGUAGE SUMMARY: Most men get cancer prevention information by coming across it passively in their daily lives, instead of actively looking for this information. Men with low health literacy are less likely to obtain cancer information both passively and actively. Men want this information. Organizations need to make this information available in many places and formats (e.g., Internet, doctor, television, sports clubs).

The SERM/SERD bazedoxifene disrupts ESR1 helix 12 to overcome acquired hormone resistance in breast cancer cells.

Acquired resistance to endocrine therapy remains a significant clinical burden for breast cancer patients. Somatic mutations in the ESR1 (estrogen receptor alpha (ERα)) gene ligand-binding domain (LBD) represent a recognized mechanism of acquired resistance. Antiestrogens with improved efficacy versus tamoxifen might overcome the resistant phenotype in ER +breast cancers. Bazedoxifene (BZA) is a potent antiestrogen that is clinically approved for use in hormone replacement therapies. We found that BZA possesses improved inhibitory potency against the Y537S and D538G ERα mutants compared to tamoxifen and has additional inhibitory activity in combination with the CDK4/6 inhibitor palbociclib. In addition, comprehensive biophysical and structural biology studies show BZA's selective estrogen receptor degrading (SERD) properties that override the stabilizing effects of the Y537S and D538G ERα mutations.

Optimization of anterior eye fluorescein viewing.

PURPOSE: To optimize anterior eye fluorescein viewing and image capture. DESIGN: Prospective experimental investigation. METHODS: The spectral radiance of ten different models of slit-lamp blue luminance and the spectral transmission of three barrier filters were measured. Optimal clinical instillation of fluorescein was evaluated by a comparison of four different instillation methods of fluorescein into 10 subjects. Two methods used a floret, and two used minims of different concentration. The resulting fluorescence was evaluated for quenching effects and efficiency over time. RESULTS: Spectral radiance of the blue illumination typically had an average peak at 460 nm. Comparison between three slit-lamps of the same model showed a similar spectral radiance distribution. Of the slit-lamps examined, 8.3% to 50.6% of the illumination output was optimized for >80% fluorescein excitation, and 1.2% to 23.5% of the illumination overlapped with that emitted by the fluorophore. The barrier filters had an average cut-off at 510 to 520 nm. Quenching was observed for all methods of fluorescein instillation. The moistened floret and the 1% minim reached a useful level of fluorescence in on average approximately 20s ( approximately 2.5x faster than the saturated floret and 2% minim) and this lasted for approximately 160 seconds. CONCLUSIONS: Most slit-lamps' blue light and yellow barrier filters are not optimal for fluorescein viewing and capture. Instillation of fluorescein using a moistened floret or 1% minim seems most clinically appropriate as lower quantities and concentrations of fluorescein improve the efficiency of clinical examination.

Systematic reviews of and integrated report on the quantitative, qualitative and economic evidence base for the management of obesity in men.

BACKGROUND: Obesity increases the risk of many serious illnesses such as coronary heart disease, type 2 diabetes and osteoarthritis. More men than women are overweight or obese in the UK but men are less likely to perceive their weight as a problem and less likely to engage with weight-loss services. OBJECTIVE: The aim of this study was to systematically review evidence-based management strategies for treating obesity in men and investigate how to engage men in obesity services by integrating the quantitative, qualitative and health economic evidence base. DATA SOURCES: Electronic databases including MEDLINE, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials, the Database of Abstracts of Reviews of Effects and the NHS Economic Evaluation Database were searched from inception to January 2012, with a limited update search in July 2012. Subject-specific websites, reference lists and professional health-care and commercial organisations were also consulted. REVIEW METHODS: Six systematic reviews were conducted to consider the clinical effectiveness, cost-effectiveness and qualitative evidence on interventions for treating obesity in men, and men in contrast to women, and the effectiveness of interventions to engage men in their weight reduction. Randomised controlled trials (RCTs) with follow-up data of at least 1 year, or any study design and length of follow-up for UK studies, were included. Qualitative and mixed-method studies linked to RCTs and non-randomised intervention studies, and UK-based, men-only qualitative studies not linked to interventions were included. One reviewer extracted data from the included studies and a second reviewer checked data for omissions or inaccuracies. Two reviewers carried out quality assessment. We undertook meta-analysis of quantitative data and a realist approach to integrating the qualitative and quantitative evidence synthesis. RESULTS: From a total of 12,764 titles reviewed, 33 RCTs with 12 linked reports, 24 non-randomised reports, five economic evaluations with two linked reports, and 22 qualitative studies were included. Men were more likely than women to benefit if physical activity was part of a weight-loss programme. Reducing diets tended to produce more favourable weight loss than physical activity alone (mean weight change after 1 year from a reducing diet compared with an exercise programme -3.2 kg, 95% CI -4.8 kg to -1.6 kg). The type of reducing diet did not affect long-term weight loss. A reducing diet plus physical activity and behaviour change gave the most effective results. Low-fat reducing diets, some with meal replacements, combined with physical activity and behaviour change training gave the most effective long-term weight change in men [-5.2 kg (standard error 0.2 kg) after 4 years]. Such trials may prevent type 2 diabetes in men and improve erectile dysfunction. Although fewer men joined weight-loss programmes, once recruited they were less likely to drop out than women (difference 11%, 95% CI 8% to 14%). The perception of having a health problem (e.g. being defined as obese by a health professional), the impact of weight loss on health problems and desire to improve personal appearance without looking too thin were motivators for weight loss amongst men. The key components differ from those found for women, with men preferring more factual information on how to lose weight and more emphasis on physical activity programmes. Interventions delivered in social settings were preferred to those delivered in health-care settings. Group-based programmes showed benefits by facilitating support for men with similar health problems, and some individual tailoring of advice assisted weight loss in some studies. Generally, men preferred interventions that were individualised, fact-based and flexible, which used business-like language and which included simple to understand information. Preferences for men-only versus mixed-sex weight-loss group programmes were divided. In terms of context, programmes which were cited in a sporting context where participants have a strong sense of affiliation showed low drop out rates and high satisfaction. Although some men preferred weight-loss programmes delivered in an NHS context, the evidence comparing NHS and commercial programmes for men was unclear. The effect of family and friends on participants in weight-loss programmes was inconsistent in the evidence reviewed - benefits were shown in some cases, but the social role of food in maintaining relationships may also act as a barrier to weight loss. Evidence on the economics of managing obesity in men was limited and heterogeneous. LIMITATIONS: The main limitations were the limited quantity and quality of the evidence base and narrow outcome reporting, particularly for men from disadvantaged and minority groups. Few of the studies were undertaken in the UK. CONCLUSIONS: Weight reduction for men is best achieved and maintained with the combination of a reducing diet, physical activity advice or a physical activity programme, and behaviour change techniques. Tailoring interventions and settings for men may enhance effectiveness, though further research is needed to better understand the influence of context and content. Future studies should include cost-effectiveness analyses in the UK setting. FUNDING: This project was funded by the NIHR Health Technology Assessment programme.

The effects of coloured light filter overlays on reading rates in age-related macular degeneration.

PURPOSE: To determine the effect of coloured light filter overlays on reading rates for people with age-related macular degeneration (AMD). METHOD: Using a prospective clinical trial design, we examined the null hypothesis that coloured light filter overlays do not improve reading rates in AMD when compared to a clear filter. Reading rates for 12 subjects with non-exudative AMD, associated with a relative scotoma and central fixation (mean age 81 years, SD 5.07 years) were determined using the Rate of Reading Test (printed, nonsense, lower case sans serif, stationary text) with 10 different, coloured light filter overlays (Intuitive Overlays); figures in brackets are percentage transmission values); rose (78%), pink (78%), purple (67%), aqua (81%), blue (74%), lime-green (86%), mint-green (85%), yellow (93%), orange (83%) and grey (71%). A clear overlay (Roscolene # 00) (360 cdm-2) with 100% transmittance was used as a control. RESULTS: Anova indicated that there was no statistically significant difference in reading rates with the coloured light filter overlays compared to the clear filter. Furthermore, chi-squared analysis indicated that the rose, purple and blue filters had a significantly poorer overall ranking in terms of reading rates compared to the other coloured and clear light filters. CONCLUSION: Coloured light filter overlays are unlikely to provide a clinically significant improvement in reading rates for people with non-exudative AMD associated with a relative scotoma and central fixation.

Effect of light filters on reading speed in normal and low vision due to age-related macular degeneration.

PURPOSE: To investigate the effects of light filters on reading speed in normal and low vision due to age-related macular degeneration (AMD). METHODS: Reading speed was determined for 12 subjects with normal vision and 12 subjects with non-exudative AMD using stationary lowercase nonsensical print in Times Roman font and four light filters; a yellow Corning Photochromic Filter (CPF) 450, a grey neural density (ND) filter, an individual filter obtained using the Intuitive Colorimeter and a clear filter. RESULTS: There was no statistically significant light filter effect on reading speed for the normal subjects. The AMD group demonstrated a statistically significant 5% average improvement in reading speed with the CPF450 compared with the other filters although some AMD subjects had improvements of 10-15%. CONCLUSIONS: Light filters obtained using the Intuitive Colorimeter(R) performed poorly when compared with the CPF450, ND and clear filters for both the study groups. For the AMD group, average reading speed was statistically greater with the CPF450 than the other filters, however it is questionable whether the improvement (5%) would be clinically significant. As some of the subjects with AMD had greater improvements with the CPF450 we advocate clinical assessment of light filters using existing protocols on an individual basis.

Do tinted lenses or filters improve visual performance in low vision? A review of the literature.

This is a review of studies that have investigated the proposed rehabilitative benefit of tinted lenses and filters for people with low vision. Currently, eye care practitioners have to rely on marketing literature and anecdotal reports from users when making recommendations for tinted lens or filter use in low vision. Our main aim was to locate a prescribing protocol that was scientifically based and could assist low vision specialists with tinted lens prescribing decisions. We also wanted to determine if previous work had found any tinted lens/task or tinted lens/ocular condition relationships, i.e. were certain tints or filters of use for specific tasks or for specific eye conditions. Another aim was to provide a review of previous research in order to stimulate new work using modern experimental designs. Past studies of tinted lenses and low vision have assessed effects on visual acuity (VA), grating acuity, contrast sensitivity (CS), visual field, adaptation time, glare, photophobia and TV viewing. Objective and subjective outcome measures have been used. However, very little objective evidence has been provided to support anecdotal reports of improvements in visual performance. Many studies are flawed in that they lack controls for investigator bias, and placebo, learning and fatigue effects. Therefore, the use of tinted lenses in low vision remains controversial and eye care practitioners will have to continue to rely on anecdotal evidence to assist them in their prescribing decisions. Suggestions for future research, avoiding some of these experimental shortcomings, are made.

The construction of a model eye for investigation of laser-tissue interactions in scanning laser ophthalmoscopy.

PURPOSE: To develop a model eye to study laser-tissue interactions during retinal imaging with scanning ophthalmoscopy. METHODS: A model eye was designed to match the optical properties of the human eye based on the Bennett and Rabbetts schematic eye. RESULTS: Alterations in axial length resulted in changes in refractive error similar to those in the human eye (3.70 D for 1 mm in axial length). Perfusion-fixed retinal tissue could be successfully imaged using the Heidelberg Retina Tomograph and Optical Coherence Tomograph to provide images that are similar in quality to those obtained. CONCLUSIONS: The model eye should be a valuable tool for investigating laser-tissue interactions during scanning laser ophthalmoscopy and the derivation of digital retinal and tomographic images. This model should also enable a determination of the accuracy with which digital imaging techniques, such as the optical coherence tomograph and Heidelberg Retina Tomograph, measure retinal structure.