Granzyme B PET Imaging of Immune Checkpoint Inhibitor Combinations in Colon Cancer Phenotypes

PURPOSE

Immune checkpoint inhibitor (ICI) monotherapy and combination regimens are being actively pursued as strategies to improve durable response rates in cancer patients. However, the biology surrounding combination therapies is not well understood and may increase the likelihood of immune-mediated adverse events. Accurate stratification of ICI response by non-invasive PET imaging may help ensure safe therapy management across a wide number of cancer phenotypes.

PROCEDURES

We have assessed the ability of a fluorine-labelled peptide, [18F]AlF-mNOTA-GZP, targeting granzyme B, to stratify ICI response in two syngeneic models of colon cancer, CT26 and MC38. In vivo tumour uptake of [18F]AlF-mNOTA-GZP following ICI monotherapy, or in combination with PD-1 was characterised and correlated with changes in tumour-associated immune cell populations.

RESULTS

[18F]AlF-mNOTA-GZP showed good predictive ability and correlated well with changes in tumour-associated T cells, especially CD8+ T cells; however, overall uptake and response to monotherapy or combination therapies was very different in the CT26 and MC38 tumours, likely due to the immunostimulatory environment imbued by the MSI-high phenotype in MC38 tumours.

CONCLUSIONS

[18F]AlF-mNOTA-GZP uptake correlates well with changes in CD8+ T cell populations and is able to stratify tumour response to a range of ICIs administered as monotherapies or in combination. However, tracer uptake can be significantly affected by preexisting phenotypic abnormalities potentially confusing data interpretation.

0007 Daytime Sleep in Night Shift Workers: Quantifying the Role of Circadian Misalignment

Introduction

Circadian misalignment is commonly cited as a culprit of daytime sleep disturbances in night shift workers; however, the specific impact and magnitude that circadian misalignment has on daytime sleep has not been well-characterized in larger samples of night shift workers.

Methods

Participants included fixed-night shift workers (n=52, ages 18–50) who completed an 8-hour daytime polysomnography (PSG) in the lab following a night shift. Measures of sleep disturbances included: difficulty falling asleep (sleep onset latency [SOL], latency to persistent sleep [LPS]), difficulty staying asleep (sleep efficiency [SE], wake after sleep onset [WASO]), and sleep duration (total sleep time [TST]). Melatonin samples were collected hourly for 24 hours under dim light (<10 lux) and used to determine dim light melatonin offset (DLMOff). Circadian misalignment (CM) was calculated as the time difference between bedtime and DLMOff (higher values represented sleeping after DLMOff), and correlated with PSG sleep variables.

Results

CM was significantly associated with difficulty staying asleep (WASO: r=0.48, p<0.001; SE: r=-0.45, p<0.001), and sleep duration (TST: r=-0.38, p<0.01). Specifically, every 3 hours of CM on average added 19.2 minutes of WASO and reduced TST by 15 minutes. In contrast, CM was not significantly correlated with sleep onset difficulties (SOL: r=-0.27; LPS: r=-0.02).

Conclusion

These data suggest that circadian misalignment in shift workers may be a better predictor of difficulties staying asleep and sleep duration during the day relative to difficulties falling asleep. Because longer work hours (10–12 hours) are common in night shift worker, it may be that sleep initiation difficulties associated with circadian misalignment is masked by elevated fatigue or an increased homeostatic drive from prolonged wakefulness. These results may help guide decisions about the magnitude of phase shifts required (e.g., with light therapy) for the desired improvement in daytime sleep.

Support

Support for this study was provided to PC by the NHLBI (K23HL138166)

0006 The Role of Stress in Sleep in Night Shift Workers: Going Beyond Circadian Misalignment

Introduction

Despite a growing need for nighttime work, few studies have characterized the causes of sleep disturbance in night shift workers beyond circadian misalignment. Recent research suggest that high sleep reactivity to stress (a predisposition for sleep disturbance due to stress) may also lead to sleep difficulties in shift workers. This study investigated if sleep reactivity is an independent predictor of daytime sleep disturbances after controlling for circadian phase.

Methods

Night shift workers (N= 48) completed an 8 hour polysomnography (PSG) during the daytime following a night shift (9am - 4pm). Circadian phase was measured using melatonin assays of saliva samples collected over 24 hours under dim light (<10 lux; Dim Light Melatonin Onset [DLMO]). Sleep reactivity was measured using the Ford Insomnia Response to Stress Test (FIRST). Linear regressions were conducted with PSG sleep parameters as outcome variables: difficulty falling asleep (Sleep Onset Latency [SOL] and Latency to Persistent Sleep [LPS]), difficulty staying asleep (Wake After Sleep Onset [WASO]), and sleep duration (Total Sleep Time [TST]). FIRST was tested as a predictor controlling for DLMO.

Results

After controlling for circadian phase, higher FIRST scores was associated with more difficulty staying asleep (WASO: t[45]=4.059, p<0.001) and shorter sleep duration (TST: t[45] = -4.403, p<0.0001), but not predictive of difficulty falling asleep (SOL: p>0.05). However, higher FIRST scores did predict a longer latency to persistent sleep (LPS: t[45]=2.272, p<0.05).

Conclusion

These results suggest that sleep reactivity to stress and circadian misalignment are independent processes that are both associated with disrupted daytime sleep in night shift workers. Given that night shift work can also cause psychosocial stress, treatments focused on circadian misalignment alone may not be sufficient. Our study highlights the need to consider sleep reactivity in the clinical management of shift work disorder.

Support

Support for this study was provided to PC by NHLBI (K23HL138166).

0203 To and From the Night Shift: Risky On-the-Road Driving in Night Shift Workers

Introduction

Drowsy driving is a common occupational hazard for night shift workers (NSWs). While sleep loss is commonly identified as the primary culprit of drowsy driving, another critical factor to consider is circadian phase. However, the role of circadian phase in driving safety has not been well characterized in NSWs. This study examined if dim light melatonin offset (DLMOff, i.e. the cessation of melatonin secretion) is also a relevant phase marker of susceptibility to four different subtypes of risky on-the-road driving behaviors.

Methods

On-the-road driving was monitored over 8 weeks via a mobile application that tracked risky driving behaviors using accelerometer and GPS data from cell phones (N=15; 3052 total driving events recorded). Risky driving behaviors included: 1) frequency of hard-braking events, 2) frequency of aggressive-acceleration events, 3) duration of excessive-speeding, and 4) duration of phone-usage. At week 2, participants spent 24 hours in-lab where hourly saliva samples were collected and assayed for melatonin, and DLMOff was calculated. Phase angle of driving events relative to DLMOff was used as the predictor in nested mixed-effects regressions, with risky driving behaviors as the outcome variables.

Results

The most common occurrences of risky driving were phone-usage and hard-braking. On average, NSWs had 46.7% and 42.0% of driving events with at least one occurrence of phone-usage and hard-braking, respectively. Rates of aggressive-acceleration and speeding were 24.4% and 20.4%. Positive phase angles (i.e. driving after DLMOff) were associated with reduced rates of hard-braking and aggressive-acceleration, but not of phone-usage and excessive-speeding. Specifically, rates of hard-braking and aggressive-acceleration decreased by 4.5% (p<.01) and 3.4% (p=.05) every two hours following DLMOff, respectively.

Conclusion

The study suggests DLMOff appears to be an important variable for predicting accident risk in NSWs. If replicated, circadian phase should be considered in recommendations to increase occupational health and safety of NSWs.

Support

Support for this study was provided to PC by NHLBI (K23HL138166).

0465 Association Between Physical or Sexual Abuse and Sleep Reactivity in Patients with Insomnia

Introduction

Physical and sexual abuse are common and have demonstrated associations with insomnia. A common factor predisposing individuals to the development of insomnia is sleep reactivity, yet no studies have determined the relationship between sleep reactivity and physical and/or sexual abuse.

Methods

Patients with DSM-5 insomnia disorder (N = 658; 519 F; mean age = 45.03) participated in an online randomized controlled trial of behavioral treatment of insomnia. Participants completed the Insomnia Severity Index (ISI), Ford Insomnia Response to Stress Test (FIRST), and demographic information at baseline. Abuse history was assessed with a single 4-choice item asking participants if they had a history of physical or sexual abuse. One-way analysis of variance was used to determine the level of sleep reactivity in each of the 4 abuse groups (none, physical, sexual, both) controlling for insomnia (ISI). Post-hoc analyses also compared differences in self-reported difficulties falling and staying asleep.

Results

Compared to those with no abuse history (n = 465), patients who reported both physical and sexual abuse (n = 50) had significantly elevated FIRST scores (p < .001). Results remained significant after controlling for severity of insomnia, age, and gender. Post-hoc analyses showed group differences in sleep onset latency but not wake after sleep onset.

Conclusion

Combined physical and sexual abuse are associated with higher levels of sleep reactivity to stress, and that the effects may be most prominent for difficulties falling asleep and not sleep maintenance. Prospective studies are needed to determine the potential effects of abuse on sleep reactivity, and whether sensitization of the sleep system to stress constitutes an etiological pathway in the development of insomnia disorder in survivors of abuse. Future work should also investigate potential overlapping biological markers of abuse and sleep reactivity.

Support

This study was funded by the Robert Wood Johnson Foundation (PI: Drake).

Children and adolescents with type 1 and type 2 diabetes mellitus in the Pediatric Diabetes Consortium Registries: comparing clinical characteristics and glycaemic control

AIM

To compare the characteristics of children and adolescents with type 1 vs. type 2 diabetes in the Pediatric Diabetes Consortium (PDC) registries.

METHODS

Participants were 10 to < 21 years of age at diagnosis; there were 484 with type 1 diabetes and 1236 with type 2 diabetes.

RESULTS

Children and adolescents with type 2 diabetes were more likely to be female, overweight/obese, and from low-income, minority ethnic families. Children and adolescents with type 1 diabetes were more likely to present with diabetic ketoacidosis and have higher mean HbA_1c levels at diagnosis. More than 70% in both cohorts achieved target HbA_1c levels < 58 mmol/mol (< 7.5%) within 6 months, but fewer participants with type 1 than type 2 diabetes were able to maintain target HbA_1c levels after 6 months consistently throughout 3 years post diagnosis. Of the 401 participants with type 2 diabetes with ≥ 24 months diabetes duration on enrolment in the registry, 47% required no insulin treatment. Median C-peptide levels were 1.43 mmol/l in the subset of participants with type 2 diabetes in whom it was measured, but only 0.06 mmol/l in the subset with type 1 diabetes.

CONCLUSIONS

Although families of children and adolescents with type 2 diabetes face greater socio-economic obstacles and risk factors for poor diabetes outcomes, the greater retention of residual endogenous insulin secretion likely contributes to the increased ability of children and adolescents with type 2 diabetes to maintain target HbA_1c during the first 3 years of diabetes diagnosis.

[Effects of low temperature on trehalose and trehalase contents in Culex pipiens pallens]

OBJECTIVE

To examine the effect of low temperature on trehalose and trehalase levels in Culex pipiens pallens.

METHODS

The fourth instar larvae and female adult mosquitoes of Cx. pipiens pallens were exposed at 4 ℃ for 0, 1, 3, 6, 12, 18, 24 h and 0, 1, 3, 6, 12, 18, 24, 36, 48, 72 h, respectively. Then, the trehalose and trehalase contents were detected by enzyme-linked immunosorbent assay (ELISA) in mosquitoes.

RESULTS

The contents of trehalose and trehalase significantly increased in the larval and female adult mosquitoes post-exposure to low temperature. The changing trend of trehalose levels was consistent in the larval and female adult mosquitoes, and the highest levels were (2.458 8 ± 0.379 2) mg/g and (2.825 7 ± 0.211 1) mg/g 3 h post-exposure to low temperature, respectively. The trehalose and trehalase levels fluctuated greatly within the first 6 h post-exposure to low temperature. Following adaptation for a period of time, the trehalose and trehalase levels remained at a relatively high level.

CONCLUSIONS

Low temperature may induce the production of trehalose and trehalase in Cx. pipiens pallens, and the trehalose and trehalase may play an important role in the improvement of the cold resistance.

LncRNA KCNQ1OT1 controls cell proliferation, differentiation and apoptosis by sponging miR-326 to regulate c-Myc expression in acute myeloid leukemia

Long noncoding RNAs (lncRNAs) have been reported to play essential roles in development and treatment of acute myeloid leukemia (AML). However, the role of lncRNA potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (KCNQ1OT1) in AML progression and its mechanism remain largely unknown. The expressions of KCNQ1OT1, microRNA-326 (miR-326) and c-Myc were measured by quantitative real-time polymerase chain reaction and western blot, respectively. Phorbol myristate acetate (PMA) was used for cell differentiation. Cell proliferation, apoptosis and differentiation were measured by MTT assay, flow cytometry and qRT-PCR, respectively. The interaction between miR-326 and KCNQ1OT1 or c-Myc was explored by luciferase activity, RNA immunoprecipitation or RNA pull-down assay. We found that the expression of KCNQ1OT1 was enhanced in AML samples compared with control. KCNQ1OT1 knockdown inhibited cell proliferation but promoted apoptosis and cell differentiation. KCNQ1OT1 was a decoy of miR-326 and c-Myc was a target of miR-326. KCNQ1OT1 regulated AML cell proliferation, apoptosis and differentiation by sponging miR-326. Moreover, overexpression of miR-326 suppressed proliferation but promoted apoptosis and PMA-induced differentiation by targeting c-Myc in AML cells. Besides, c-Myc protein level was suppressed by KCNQ1OT1 interference and rescued by miR-326 abrogation. Our data showed that KCNQ1OT1 regulates proliferation, differentiation and apoptosis in AML cells by acting as a competing endogenous RNA (ceRNA) for miR-326 to regulate c-Myc, providing a novel avenue for AML treatment.

[Study on insecticide resistance of Culex pipiens pallens in southwest region of Shandong Province]

OBJECTIVE

To explore the sensitivity of Culex pipiens pallens to common chemical insecticides in the southwestern region of Shandong Province, so as to provide a theoretical basis for the development of reasonable and effective mosquito control measures.

METHODS

The resistance of Cx. pipiens pallens larvae to 5 chemical insecticides, such as cypermethrin, deltamethrin, DDVP, propoxur, and acetofenate were tested by using the WHO biological test method in 2018, and the co-toxicity coefficients after compounding the above-mentioned insecticides were tested by using a drug compounding method.

RESULTS

The resistance indexes of Cx. pipiens pallens to cypermethrin, deltamethrin, DDVP, propoxur, and acetofenate in 3 cities were 144.43-557.54, 118.17-445.33, 6.44-19.00, 2.37-8.10, and 0.88-2.98, respectively, and expect the difference between the DDVP resistances of Cx. pipiens pallens in Jining City and Heze City was not statistically significant (P > 0.05), all the other differences were statistically significant (all P < 0.05). The synergistic coefficients of cypermethrin + DDVP, cypermethrin + propoxur, DDVP + acetofenate, and propoxur + acetofenate were 199.58 - 456.95, 190.56 - 292.37, 123.32 - 319.24, and 192.31 - 367.32, respectively. The lower synergism was observed by using the mixture of DDVP + propoxur (synergistic coefficient: 99.87-108.36) .

CONCLUSIONS

After decades of chemical control, Cx. pipiens pallens in the southwestern region of Shandong Province has produced different degrees of resistance to common chemical insecticides. Therefore, comprehensive control measures should be taken to control mosquito breeding and prevent the development of insecticide resistance.

Imaging adipose tissue browning using the TSPO-18kDa tracer [18F]FEPPA

Objectives

The browning of white adipose tissue (WAT) into beige has been proposed as a strategy to enhance energy expenditure to combat the growing epidemic of obesity. Research into browning strategies are hampered by the lack of sensitive, translatable, imaging tools capable of detecting beige fat mass non-invasively. [¹⁸F]FDG is able to detect activated beige fat but provides little information on unstimulated beige fat mass. We have assessed the use of [¹⁸F]FEPPA, a tracer for the TSPO-18KDa found on the outer mitochondrial membrane, as an alternative imaging agent capable of detecting unstimulated brown fat (BAT) and beige fat.

Methods

Female Balb/c mice (n = 5) were treated for 7 days with the β3 adrenergic agonist CL-316,243 to induce the browning of inguinal WAT (beige fat). Animals were imaged longitudinally with [¹⁸F]FDG and [¹⁸F]FEPPA and uptake in interscapular BAT and inguinal WAT assessed. The browning of inguinal WAT was confirmed using H&E and immunohistochemical detection of UCP-1 and TSPO.

Results

Repeated dosing with β3-adrenergic agonist CL-316,243 caused a significant increase in [¹⁸F]FDG uptake in both interscapular BAT and inguinal WAT associated with the increased metabolic activity of brown and beige adipocytes respectively. [¹⁸F]FEPPA uptake was likewise increased in inguinal WAT but showed no increase in BAT uptake due to stimulation over the same time course. Furthermore, inguinal WAT uptake was unaffected by pharmacological blockade, indicating that [¹⁸F]FEPPA uptake is associated with the expression of mitochondria in BAT and beige adipocytes and independent of activation.

Conclusion

These data show that [¹⁸F]FEPPA can detect BAT and newly formed beige fat under non-stimulated, thermoneutral conditions and that uptake after stimulation is linked to mitochondrial expression as opposed to activation.

•

TSPO-18kDa tracers can detect BAT under non-stimulated, thermoneutral conditions.

•

TSPO-18kDa tracers can detect the formation of beige adipocytes in white adipose tissue.

•

TSPO-18kDa tracers may aid in the development of new approaches to treat obesity.

Preparation and evaluation of tilmicosin microspheres and lung-targeting studies in rabbits

Tilmicosin (TMS) is a macrolide used extensively for pulmonary infections in clinical veterinary medicine. However, TMS has frequent administration and short elimination half-life. Therefore, tilmicosin-gelatine microspheres (TMS-GMS) were prepared by an emulsion-chemical cross-linking technique as a sustained-release formulation to extend drug half-life. The particle size distribution, in-vitro sustained-release properties, stability, and physical characteristics, as well as pharmacokinetic (PK) characteristics, were evaluated in rabbits. TMS-GMS were spherical in shape and had a mean diameter of 11.34±1.20μm; 95.65% of the microspheres varied in size from 5.0 to 25.0μm. Light and thermal stability tests indicated no significant changes in all observed indices. Importantly, compared to crude TMS, slower release of TMS from TMS-GMS was noted in drug release studies (in vitro). Pharmacokinetic (PK) characteristics were examined in the lung, liver, heart, kidney and muscle tissue of rabbits following IM injection of TMS-GMS or TMS-injection at a dose of 10mg/kg. The elimination half-life of TMS-GMS (59.21±0.21h) was longer than that of TMS-injection (38.56±0.13h) in the lung. The ratio of peak concentration (C_e) of TMS-GMS to TMS-injection was 2.19 (>1) in the lung, demonstrating the selectivity of TMS-GMS to target the lung compared to that of other tissues (C_e<1). Interestingly, the uptake value of TMS from TMS-GMS was 8.48 times higher in the lung than that for the TMS-injection, and was slightly higher than in the liver (1.85), heart (1.72), kidney (2.44) and muscle (2.79) tissues. TMS-GMS is a sustained-release formulation of TMS with potential to be used in veterinary clinical applications; possible benefits include lung-targeting and prolonged elimination half-life.