Circadian disruption and cancer risk: A new concept of stromal niche

Interactions of circadian clock genes with the hallmarks of cancer

The molecular machinery of the circadian clock regulates the expression of many genes and processes in the organism, allowing the adaptation of cellular activities to the daily light-dark cycles. Disruption of the circadian rhythm can lead to various pathologies, including cancer. Thus, disturbance of the normal circadian clock at both genetic and environmental levels has been described as an independent risk factor for cancer. In addition, researchers have proposed that circadian genes may have a tissue-dependent and/or context-dependent role in tumorigenesis and may function both as tumor suppressors and oncogenes. Finally, circadian clock core genes may trigger or at least be involved in different hallmarks of cancer. Hence, expanding the knowledge of the molecular basis of the circadian clock would be helpful to identify new prognostic markers of tumorigenesis and potential therapeutic targets.

Psychometric Testing of a Food Timing Questionnaire and Food Timing Screener

BACKGROUND

Circadian rhythms coordinate multiple biological processes, and time of eating is an important entrainer of peripheral circadian clocks, including those in the gastrointestinal tract and liver. Whereas time of eating can be assessed through valid and reliable tools designed to measure nutrient intake (24-h recalls), currently there is no easily administered, valid, and reliable tool designed to specifically assess both time of food intake and sleep.

OBJECTIVES

The objective of this study was to test the validity and reliability of 2 questionnaires developed to measure food and sleep-wake timing, the Food Timing Questionnaire (FTQ) and Food Timing Screener (FTS), and the agreement between these 2 tools.

METHODS

The content validity of these tools was assessed by an expert panel of 10 registered dietitian nutritionists. Adult volunteers (n = 61) completed both tools to assess internal consistency and test-retest reliability. Criterion-related validity was determined through the association of FTQ and FTS with 2 valid instruments, the Automated Self-Administered 24-hour recall (ASA24®) Dietary Assessment tool and the Munich Chronotype Questionnaire. Agreement between the FTQ and FTS was tested by calculating the Pearson's correlations for both food and sleep-wake timing.

RESULTS

The content validity indexes for both tools were >0.80, and internal consistency and test-retest reliability coefficients were >0.50 for all meals and sleep-wake times. Correlation coefficients were >0.40 between both tools and criterion measures of food intake and sleep except for snacks. Correlations between the FTQ and FTS for all eating events and sleep were >0.60 except for snack 1.

CONCLUSIONS

Both the FTQ and FTS are valid and reliable instruments for meal timing and sleep. However, further psychometric testing in a more expansive and diverse sample will improve the ability of these tools to accurately assess food timing and sleep and their impact on health outcomes.

Depletion of WNT10A Prevents Tumor Growth by Suppressing Microvessels and Collagen Expression

Background: We recently reported that WNT10A plays a pivotal role in wound healing by regulating collagen expression/synthesis, as the depletion of WNT10A dramatically delays skin ulcer formation. WNT signaling also has a close correlation with the cancer microenvironment and proliferation, since tumors are actually considered to be 'unhealing' or 'overhealing' wounds. To ascertain the in vivo regulatory functions of WNT10A in tumor growth, we examined the net effects of WNT10A depletion using Wnt10a-deficient mice (Wnt10a -/-). Methods and Results: We subjected C57BL/6J wild-type (WT) or Wnt10a -/- mice to murine melanoma B16-F10 cell transplantation. Wnt10a -/- mice showed a significantly smaller volume of transplanted melanoma as well as fewer microvessels and less collagen expression and more necrosis than WT mice. Conclusions: Taken together, our observations suggest that critical in vivo roles of Wnt10a-depleted anti-stromagenesis prevent tumor growth, in contrast with true wound healing/scarring.

Association of Time-Varying Rest-Activity Rhythm With Survival in Older Adults With Lung Cancer

BACKGROUND

To the best of our knowledge, this is the first study to examine the relationship of rest-activity rhythm with survival in older adults with lung cancer and to consider variations in rest-activity rhythm over time.

OBJECTIVE

The aim of this study was to explore the relationship between rest-activity rhythm variations and survival in 33 older adults with lung cancer by considering rest-activity rhythm as a time-dependent covariate over time.

METHODS

In this prospective study with 5 repeated measurements, patients' rest-activity rhythm over 3 days was measured using actigraphy. The rest-activity rhythm was represented using the dichotomy index I (in-bed activity) < O (out-of-bed activity). The median I < O was used as the cutoff point, with an I < O of greater than or equal to 85.59% and less than 85.59% indicating robust and disrupted rest-activity rhythms, respectively. Data were analyzed using the Cox regression model with time-dependent repeated measurements of a covariate.

RESULTS

In the time-dependent multivariate Cox model, a disrupted rest-activity rhythm was independently associated with a higher risk of death than was a robust rest-activity rhythm (hazard ratio, 16.05; P = .009).

CONCLUSION

A time-varying rest-activity rhythm is incrementally associated with mortality in older adults with lung cancer and represents a rigorous and independent prognostic factor for their survival.

IMPLICATIONS FOR PRACTICE

Clinicians may need to pay more attention to the rest-activity rhythms of older adults with lung cancer during disease progression. Future studies should account for the variation in rest-activity rhythm over time.

Chronotype, social jet lag, sleep debt and food timing in inflammatory bowel disease

The preference of the sleep/wake cycle can be grouped into categories or chronotypes. Inflammatory bowel disease (IBD) has been linked to poor sleep quality which correlates with disease severity. Social jet lag (SJL) is the difference between sleep timing on work and free days and is a marker for circadian misalignment which has been linked to increased inflammation. We investigated whether chronotype, SJL, sleep debt (SD), and food timing were associated with an IBD specific complications and a lower quality of life. Overall, 191 subjects (115 IBD subjects and 76 healthy controls (HC)) completed the Pittsburgh Sleep Quality Index (PSQI), Morningness-Eveningness Questionnaire (MEQ), Munich ChronoType Questionnaire (MCTQ), Short Inflammatory Bowel Disease Questionnaire (SIBDQ), and a structured Food Timing Questionnaire. Later chronotype (by MEQ) was associated with a worse SIBDQ (r = -0.209; P < 0.05). SJL was increased in IBD at 1.32 h ± 1.03 vs. 1.05 h ± 0.97 in HC, P < 0.05, when adjusted for age. SJL (>2 h) was present in 40% of severe/complicated Crohn's patients (fistulizing or structuring Crohn's or history of Crohn's related surgery) compared to only 16% of uncomplicated Crohn's patients (P < 0.05). Sleep debt was increased in IBD subjects compared to HC at 21.90 m ± 25.37 vs. 11.49 m ± 13.58, P < 0.05. IBD subjects with inconsistent breakfast or dinner times had lower SIBDQ scores (4.78 ± 1.28 vs. 5.49 ± 1.02, P < 0.05; 4.95 ± 0.31 vs. 5.42 ± 0.32, P < 0.05 respectively). In summary, later chronotype, and markers of circadian misalignment (social jet lag, sleep debt, and inconsistent meal timing) were associated with IBD disease specific complications and/or lower quality of life.

Efficacy and safety of chronomodulated chemotherapy for patients with metastatic colorectal cancer: a systematic review and meta-analysis

AIM

Chronomodulated chemotherapy has been reported to be superior to conventional chemotherapy, but the results from randomized controlled trials (RCTs) are inconsistent. We performed a meta-analysis to summarize the efficacy and safety of chronomodulated chemotherapy for patients with metastatic colorectal cancer.

METHODS

A literature search for relevant RCTs comparing the efficacy and safety of chronomodulated chemotherapy and conventional chemotherapy was performed. The main outcomes were overall survival (OS), objective response rate (ORR) and toxicity (grade 3/4), which included vomiting and nausea, diarrhea, mucositis, neutropenia and peripheral sensory neuropathy. Pooled relative risks (RRs) and hazard ratios (HRs) with their 95% confidence intervals (95% CIs) were estimated.

RESULTS

Six RCTs involving 1347 patients were included. Chronomodulated chemotherapy showed no advantages for OS (HR = 0.95; 95% CI, 0.84-1.08; P = 0.463) or ORR (RR = 1.06; 95% CI, 0.81-1.39; P = 0.499). The two groups were similar in terms of grade 3/4 vomiting and nausea (RR = 1.02; 95% CI, 0.78-1.35; P = 0.872), diarrhea (RR = 1.44; 95% CI, 0.87-2.36; P = 0.149) or peripheral sensory neuropathy (RR = 0.86; 95% CI, 0.56-1.34; P = 0.512), whereas decreased risks of mucositis (RR = 0.31; 95% CI, 0.14-0.66; P = 0.000) and neutropenia (RR = 0.40; 95% CI, 0.27-0.57; P = 0.000) were observed in chronomodulated chemotherapy.

CONCLUSION

Chronomodulated chemotherapy may be favorable to reduce the risks of certain side effects, but there is no current evidence for improvement in OS or ORR. Our analysis suggests that the available data does not support the use of chronomodulated chemotherapy.

The circadian clock gene Bmal1 acts as a potential anti-oncogene in pancreatic cancer by activating the p53 tumor suppressor pathway

Disruption of the circadian clock has been shown to be associated with tumor development. This study aimed to investigate the role of the core circadian gene Bmal1 in pancreatic cancer (PC). We first found that the levels of Bmal1 were downregulated in PC samples and were closely correlated with the clinicopathological features of patients. To dissect the underlying mechanism, we performed a RNA-seq assay followed by systematic gene function and pathway enrichment analyses. We detected an anti-apoptotic and pro-proliferative transcriptome profile after Bmal1 knockdown in PC cells. Further in vitro and in vivo studies confirmed that Bmal1 overexpression significantly inhibited cell proliferation and invasion and induced G2/M cell cycle arrest, whereas Bmal1 knockdown promoted PC growth, as demonstrated in Bmal1-manipulated AsPC-1 and BxPC-3 cell lines. Our mechanistic studies indicated that Bmal1 could directly bind to the p53 gene promoter and thereby transcriptionally activate the downstream tumor suppressor pathway in a p53-dependent manner. In sum, our findings suggest that Bmal1 acts as an anti-oncogene in PC and represents a potential biomarker for its diagnosis.

Mitochondrial Transcription Factor A and Mitochondrial Genome as Molecular Targets for Cisplatin-Based Cancer Chemotherapy

Mitochondria are important cellular organelles that function as control centers of the energy supply for highly proliferative cancer cells and regulate apoptosis after cancer chemotherapy. Cisplatin is one of the most important chemotherapeutic agents and a key drug in therapeutic regimens for a broad range of solid tumors. Cisplatin may directly interact with mitochondria, which can induce apoptosis. The direct interactions between cisplatin and mitochondria may account for our understanding of the clinical activity of cisplatin and development of resistance. However, the basis for the roles of mitochondria under treatment with chemotherapy is poorly understood. In this review, we present novel aspects regarding the unique characteristics of the mitochondrial genome in relation to the use of platinum-based chemotherapy and describe our recent work demonstrating the importance of the mitochondrial transcription factor A (mtTFA) expression in cancer cells.