Circadian chemotherapy for gynecological and genitourinary cancers

Tracking Daily Variations in Rest-Wake to Guide Personalized Timing of Temozolomide for High-Grade Glioma Patients

High-grade gliomas, like glioblastoma multiforme (GBM), are the most common malignant brain tumors in adults and are treated with the chemotherapy drug temozolomide (TMZ). In humans, a retrospective analysis of patients' overall survival suggests that morning dosing may confer a benefit over evening dosing. Circadian variation in O6-methylguanine-DNA methyltransferase (MGMT) gene expression and promoter methylation has been implicated in increased tumor cell sensitivity to TMZ in the morning. Although patient compliance with timed oral administration of TMZ was high in a prospective trial, it is not known whether differences in daily sleep patterns of patients impact the biological time of drug administration or overall survival. Using wrist actigraphy collected from 10 high-grade glioma patients, we quantified the moment of oral TMZ delivery in terms of wall clock time and internal biological time during the months after surgical tumor resection. We found that variation of daily rhythms within and between individuals caused dosing times to vary more in their internal biological time than wall clock time so that, for example, some doses taken by patients assigned for the evening (2000 h) were closer to the patient's internal biological morning. We conclude that wrist actigraphy provides a reliable and non-invasive estimate of personal circadian time that could improve efficacy and precision of TMZ delivery. These findings may inform personalized circadian medicine and optimized times for TMZ delivery in the clinic.

Daily glucocorticoids promote glioblastoma growth and circadian synchrony to the host

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults with a poor prognosis despite aggressive therapy. Here, we hypothesized that daily host signaling regulates tumor growth and synchronizes circadian rhythms in GBM. We find daily glucocorticoids promote or suppress GBM growth through glucocorticoid receptor (GR) signaling depending on time of day and the clock genes, Bmal1 and Cry. Blocking circadian signals, like vasoactive intestinal peptide or glucocorticoids, dramatically slows GBM growth and disease progression. Analysis of human GBM samples from The Cancer Genome Atlas (TCGA) shows that high GR expression significantly increases hazard of mortality. Finally, mouse and human GBM models have intrinsic circadian rhythms in clock gene expression in vitro and in vivo that entrain to the host through glucocorticoid signaling, regardless of tumor type or host immune status. We conclude that GBM entrains to the circadian circuit of the brain, modulating its growth through clock-controlled cues, like glucocorticoids.

Senolytics Enhance the Longevity of Caenorhabditis elegans by Altering Betaine Metabolism

Aging triggers physiological changes in organisms that are tightly linked to metabolic changes. Senolytics targeting many fundamental aging processes are currently being developed. However, the host metabolic response to natural senescence and the molecular mechanism underlying the antiaging benefits of senolytics remain poorly understood. In this study, we investigated metabolic changes during natural senescence based on the Caenorhabditis elegans model and pinpointed potential biomarkers linked to the benefits of senolytics. These results suggest that age-dependent metabolic changes during natural aging occur in C elegans. Betaine was identified as a crucial metabolite in the natural aging process. We explored the metabolic effects of aging interventions by administering 3 antiaging drugs-metformin, quercetin, and minocycline-to nematodes. Notably, betaine expression significantly increased under the 3 antiaging drug treatments. Our findings demonstrated that betaine supplementation extends lifespan, primarily through pathways associated with the forkhead box transcription factor (FoxO) signaling pathway, the p38-mitogen-activated protein kinase (MAPK) signaling pathway, autophagy, the longevity regulating pathway, and the target of rapamycin (mTOR) signaling pathway. In addition, autophagy and free radicals are altered in betaine-treated nematodes. Overall, we found that betaine is a critical metabolite during natural aging and that senolytics extend the lifespan of nematodes by increasing betaine levels and promoting autophagy and antioxidant activity. This finding suggests that betaine could be a novel therapeutic target for promoting longevity.

Identification of circadian clock-related immunological prognostic index and molecular subtypes in prostate cancer

BACKGROUND

Evidence suggests that the circadian clock (CIC) is among the important factors for tumorigenesis. We aimed to provide new insights into CIC-mediated molecular subtypes and gene prognostic indexes for prostate cancer (PCa) patients undergoing radical prostatectomy (RP) or radical radiotherapy (RT).

METHODS

PCa data from TCGA was analyzed to identify differentially expressed genes (DEGs) with significant fold changes and p-values. A prognostic index called CIC-related gene prognostic index (CICGPI) was developed through clustering methods and survival analysis and validated on multiple data sets. The diagnostic accuracy of CICGPI for resistance to chemotherapy and radiotherapy was confirmed. Additionally, the interaction between tumor immune environment and CICGPI score was explored, along with their correlation with prognosis.

RESULTS

TOP2A, APOE, and ALDH2 were used to classify the PCa patients into two subtypes. Cluster 2 had a higher risk of biochemical recurrence (BCR) than cluster 1 for PCa patients undergoing RP or RT. A CIC-related gene prognostic index (CICGPI) was constructed using the above three genes for PCa patents in the TCGA database. The CICGPI score showed good prognostic value in the TCGA database and was externally confirmed by PCa patients in GSE116918, MSKCC2010 and GSE46602. In addition, the CICGPI score had a certain and high diagnostic accuracy for tumor chemoresistance (AUC: 0.781) and radioresistance (AUC: 0.988). For gene set variation analysis, we observed that both beta alanine metabolism and limonene and pinene degradation were upregulated in cluster 1 for PCa patients undergoing RP or RT. For PCa patients undergoing RP, cell cycle, homologous recombination, mismatch repair, and DNA replication were upregulated in cluster 2. A strongly positive relationship between cancer-related fibroblasts and CICGPI score was observed in PCa patients undergoing RP or RT. Moreover, a high density of CAFs was highly closely associated with poorer BCR-free survival of PCa patients.

CONCLUSIONS

In this study, we established CIC-related immunological prognostic index and molecular subtypes, which might be useful for the clinical practice.

Circadian rhythms and breast cancer: unraveling the biological clock's role in tumor microenvironment and ageing

Breast cancer (BC) is one of the most common and fatal malignancies among women worldwide. Circadian rhythms have emerged in recent studies as being involved in the pathogenesis of breast cancer. In this paper, we reviewed the molecular mechanisms by which the dysregulation of the circadian genes impacts the development of BC, focusing on the critical clock genes, brain and muscle ARNT-like protein 1 (BMAL1) and circadian locomotor output cycles kaput (CLOCK). We discussed how the circadian rhythm disruption (CRD) changes the tumor microenvironment (TME), immune responses, inflammation, and angiogenesis. The CRD compromises immune surveillance and features and activities of immune effectors, including CD8+ T cells and tumor-associated macrophages, that are important in an effective anti-tumor response. Meanwhile, in this review, we discuss bidirectional interactions: age and circadian rhythms, aging further increases the risk of breast cancer through reduced vasoactive intestinal polypeptide (VIP), affecting suprachiasmatic nucleus (SCN) synchronization, reduced ability to repair damaged DNA, and weakened immunity. These complex interplays open new avenues toward targeted therapies by the combination of clock drugs with chronotherapy to potentiate the immune response while reducing tumor progression for better breast cancer outcomes. This review tries to cover the broad area of emerging knowledge on the tumor-immune nexus affected by the circadian rhythm in breast cancer.

Daily glucocorticoids promote glioblastoma growth and circadian synchrony to the host

Glioblastoma (GBM) is the most common primary brain tumor in adults with a poor prognosis despite aggressive therapy. A recent, retrospective clinical study found that administering Temozolomide in the morning increased patient overall survival by 6 months compared to evening. Here, we tested the hypothesis that daily host signaling regulates tumor growth and synchronizes circadian rhythms in GBM. We found daily Dexamethasone promoted or suppressed GBM growth depending on time of day of administration and on the clock gene, Bmal1. Blocking circadian signals, like VIP or glucocorticoids, dramatically slowed GBM growth and disease progression. Finally, mouse and human GBM models have intrinsic circadian rhythms in clock gene expression in vitro and in vivo that entrain to the host through glucocorticoid signaling, regardless of tumor type or host immune status. We conclude that GBM entrains to the circadian circuit of the brain, which modulates its growth through clockcontrolled cues, like glucocorticoids.

A review for the impacts of circadian disturbance on urological cancers

Circadian rhythm is an internal timing system and harmonizes a variety of cellular, behavioral, and physiological processes to daily environment. Circadian disturbance caused by altered life style or disrupted sleep patterns inevitably contributes to various disorders. As the rapidly increased cancer occurrences and subsequent tremendous financial burdens, more researches focus on reducing the morbidity rather than treating it. Recently, many epidemiologic studies demonstrated that circadian disturbance was tightly related to the occurrence and development of cancers. For urinary system, numerous clinical researches observed the incidence and progress of prostate cancer were influenced by nightshift work, sleep duration, chronotypes, light exposure, and meal timing, this was also proved by many genetic and fundamental findings. Although the epidemiological studies regarding the relationship between circadian disturbance and kidney/bladder cancers were relative limited, some basic researches still claimed circadian disruption was closely correlated to these two cancers. The role of circadian chemotherapy on cancers of prostate, kidney, and bladder were also explored, however, it has not been regularly recommended considering the limited evidence and poor standard protocols. Finally, the researches for the impacts of circadian disturbance on cancers of adrenal gland, penis, testis were not found at present. In general, a better understanding the relationship between circadian disturbance and urological cancers might help to provide more scientific work schedules and rational lifestyles which finally saving health resource by reducing urological tumorigenesis, however, the underlying mechanisms are complex which need further exploration.

Long-term survival, toxicities, and the role of chrono-chemotherapy with different infusion rates in locally advanced nasopharyngeal carcinoma patients treated with intensity-modulated radiation therapy: a retrospective study with a 5-year follow-up

Purpose

This study aimed to evaluate 5-year outcomes and the late toxicity profile of chrono-chemotherapy with different infusion rates in patients with locally advanced nasopharyngeal carcinoma (NPC).

Methods and materials

Our retrospective analysis included 70 patients with locally advanced NPC stages III and IVB (according to the 2010 American Joint Committee on Cancer staging system). Patients were treated with two cycles of induction chemotherapy (IC) before concurrent chemoradiotherapy (CCRT) at Guizhou Cancer Hospital. The IC with docetaxel, cisplatin (DDP) and fluorouracil regimen. Patients were divided into two groups during CCRT. Using a "MELODIE" multi-channel programmed pump, DDP (100 mg/m2) was administered for 12 hours from 10:00 am to 10:00 pm and repeated every 3 weeks for 2-3 cycles. DDP was administered at the peak period of 4:00 pm in the sinusoidal chrono-modulated infusion group (Arm A, n=35). The patients in Arm B received a constant rate of infusion. Both arms received radiotherapy through the same technique and dose fraction. The long-term survival and disease progression were observed.

Results

After a median follow-up of 82.8 months, the 5-year progression-free survival rate was 81.3% in Arm A and 79.6% in Arm B (P = 0.85). The 5-year overall survival rate was not significantly different between Arm A and Arm B (79.6% vs 85.3%, P = 0.79). The 5-year distant metastasis-free survival rate was 83.6% in Arm A and 84.6% in Arm B (P = 0.75). The 5-year local recurrence-free survival rate was 88.2% in Arm A and 85.3% in Arm B (P = 0.16). There were no late toxicities of grade 3-4 in either group. Both groups had grade 1-2 late toxicities. Dry mouth was the most common late toxic side effect, followed by hearing loss and difficulty in swallowing. There was no statistically significant difference between Arm A and Arm B in terms of side effects.

Conclusion

Long-term analysis confirmed that in CCRT, cisplatin administration with sinusoidal chrono-modulated infusion was not superior to the constant infusion rate in terms of long-term toxicity and prognosis.

Circadian regulation of MGMT expression and promoter methylation underlies daily rhythms in TMZ sensitivity in glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite extensive research and clinical trials, median survival post-treatment remains at 15 months. Thus, all opportunities to optimize current treatments and improve patient outcomes should be considered. A recent retrospective clinical study found that taking TMZ in the morning compared to the evening was associated with a 6-month increase in median survival in patients with MGMT-methylated GBM. Here, we hypothesized that TMZ efficacy depends on time-of-day and O6-Methylguanine-DNA Methyltransferase (MGMT) activity in murine and human models of GBM.

METHODS AND RESULTS

In vitro recordings using real-time bioluminescence reporters revealed that GBM cells have intrinsic circadian rhythms in the expression of the core circadian clock genes Bmal1 and Per2, as well as in the DNA repair enzyme, MGMT. Independent measures of MGMT transcript levels and promoter methylation also showed daily rhythms intrinsic to GBM cells. These cells were more susceptible to TMZ when delivered at the daily peak of Bmal1 transcription. We found that in vivo morning administration of TMZ also decreased tumor size and increased body weight compared to evening drug delivery in mice bearing GBM xenografts. Finally, inhibition of MGMT activity with O6-Benzylguanine abrogated the daily rhythm in sensitivity to TMZ in vitro by increasing sensitivity at both the peak and trough of Bmal1 expression.

CONCLUSION

We conclude that chemotherapy with TMZ can be dramatically enhanced by delivering at the daily maximum of tumor Bmal1 expression and minimum of MGMT activity and that scoring MGMT methylation status requires controlling for time of day of biopsy.

Circadian clock and lipid metabolism disorders: a potential therapeutic strategy for cancer

Recent research has emphasized the interaction between the circadian clock and lipid metabolism, particularly in relation to tumors. This review aims to explore how the circadian clock regulates lipid metabolism and its impact on carcinogenesis. Specifically, targeting key enzymes involved in fatty acid synthesis (SREBP, ACLY, ACC, FASN, and SCD) has been identified as a potential strategy for cancer therapy. By disrupting these enzymes, it may be possible to inhibit tumor growth by interfering with lipid metabolism. Transcription factors, like SREBP play a significant role in regulating fatty acid synthesis which is influenced by circadian clock genes such as BMAL1, REV-ERB and DEC. This suggests a strong connection between fatty acid synthesis and the circadian clock. Therefore, successful combination therapy should target fatty acid synthesis in addition to considering the timing and duration of drug use. Ultimately, personalized chronotherapy can enhance drug efficacy in cancer treatment and achieve treatment goals.

Circadian regulation of MGMT expression and promoter methylation underlies daily rhythms in TMZ sensitivity in glioblastoma

Background

Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite extensive research and clinical trials, median survival post-treatment remains at 15 months. Thus, all opportunities to optimize current treatments and improve patient outcomes should be considered. A recent retrospective clinical study found that taking TMZ in the morning compared to the evening was associated with a 6-month increase in median survival in patients with MGMT-methylated GBM. Here, we hypothesized that TMZ efficacy depends on time-of-day and O6-Methylguanine-DNA Methyltransferase (MGMT) activity in murine and human models of GBM.

Methods and Results

In vitro recordings using real-time bioluminescence reporters revealed that GBM cells have intrinsic circadian rhythms in the expression of the core circadian clock genes Bmal1 and Per2, as well as in the DNA repair enzyme, MGMT. Independent measures of MGMT transcript levels and promoter methylation also showed daily rhythms intrinsic to GBM cells. These cells were more susceptible to TMZ when delivered at the daily peak of Bmal1 transcription. We found that in vivo morning administration of TMZ also decreased tumor size and increased body weight compared to evening drug delivery in mice bearing GBM xenografts. Finally, inhibition of MGMT activity with O6-Benzylguanine abrogated the daily rhythm in sensitivity to TMZ in vitro by increasing sensitivity at both the peak and trough of Bmal1 expression.

Conclusion

We conclude that chemotherapy with TMZ can be dramatically enhanced by delivering at the daily maximum of tumor Bmal1 expression and minimum of MGMT activity.

Friend and foe: the regulation network of ascites components in ovarian cancer progression

The tumor microenvironment (TME) and its complex role in cancer progression have been hotspots of cancer research in recent years. Ascites, which occurs frequently in patients with ovarian cancer especially in advanced stages, represents a unique TME. Malignant ascites contains abundant cellular and acellular components that play important roles in tumorigenesis, growth, metastasis, and chemoresistance of ovarian cancer through complex molecular mechanisms and signaling pathways. As a valuable liquid biopsy sample, ascites fluid is also of great significance for the prognostic analysis of ovarian cancer. The components of ovarian cancer ascites are generally considered to comprise tumor-promoting factors; however, in recent years studies have found that ascites also contains tumor-suppressing factors, raising new perspectives on interactions between ascites and tumors. Malignant ascites directly constitutes the ovarian cancer microenvironment, therefore, the study of its components will aid in the development of new therapeutic strategies. This article reviews the current research on tumor-promoting and tumor-suppressing factors and molecular mechanisms of their actions in ovarian cancer-derived ascites and therapeutic strategies targeting ascites, which may provide references for the development of novel therapeutic targets for ovarian cancer in the future.

Chronotherapeutics for Solid Tumors

Circadian rhythms are internal manifestations of the 24-h solar day that allow for synchronization of biological and behavioral processes to the external solar day. This precise regulation of physiology and behavior improves adaptive function and survival. Chronotherapy takes advantage of circadian rhythms in physiological processes to optimize the timing of drug administration to achieve maximal therapeutic efficacy and minimize negative side effects. Chronotherapy for cancer treatment was first demonstrated to be beneficial more than five decades ago and has favorable effects across diverse cancer types. However, implementation of chronotherapy in clinic remains limited. The present review examines the evidence for chronotherapeutic treatment for solid tumors. Specifically, studies examining chrono-chemotherapy, chrono-radiotherapy, and alternative chronotherapeutics (e.g., hormone therapy, TKIs, antiangiogenic therapy, immunotherapy) are discussed. In addition, we propose areas of needed research and identify challenges in the field that remain to be addressed.

Circadian rhythm in prostate cancer: time to take notice of the clock

The circadian clock is an evolutionary molecular product that is associated with better adaptation to changes in the external environment. Disruption of the circadian rhythm plays a critical role in tumorigenesis of many kinds of cancers, including prostate cancer (PCa). Integrating circadian rhythm into PCa research not only brings a closer understanding of the mechanisms of PCa but also provides new and effective options for the precise treatment of patients with PCa. This review begins with patterns of the circadian clock, highlights the role of the disruption of circadian rhythms in PCa at the epidemiological and molecular levels, and discusses possible new approaches to PCa therapy that target the circadian clock.

Hsa_circ_0072309 is a prognostic biomarker and is correlated with immune infiltration in gastric cancer

Background

Hsa_circ_0072309 has been identified as a tumor suppressor in several carcinomas. However, its precise role in gastric cancer (GC) remains largely unknown. This study was aimed to explore the precise role of Hsa_circ_0072309 in GC.

Methods

The transcriptional and clinical data of stomach adenocarcinoma were downloaded using the University of California SantaCruz (UCSC) Xena browser. The circular RNA (circRNA) datasets were obtained from the Gene Expression Omnibus (GEO) database. The expression profile and survival analysis of differentially expressed micro RNAs (DEMIs) and differentially expressed messenger RNAs (DEMs) were performed. Correlations between the expression and immune infiltration of the DEMS were studied. Additionally, the expression of hsa_circ_0072309 in GC tissues and cell lines were validated, and the relationship between its expression and clinical features was investigated. Gain- and loss-of function experiments and molecular interaction experiments were also conducted.

Results

Overall, 7 differentially expressed circRNAs, 13 DEMIs, and 17 DEMs were screened. Two DEMIs (hsa_miR-34a-3p and hsa_miR-326) and five DEMs (C7, MARCKSL1, UBE2T, OLR1, and HOXC11) showed significant differences in the high- and low-risk groups. The most significantly enriched Gene Ontology terms were the circadian regulation of gene expression and protein binding. The most significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways were the PI3K-Akt and Ras signal pathways. Additionally, six genes were significantly correlated with immune infiltration. The real-time quantitative PCR (RT-qPCR) results revealed a significant downregulation of hsa_circ_0072309 in GC tissues related to tumor size, vascular invasion, and lymph node metastasis. A hsa_circ_0072309 overexpression suppressed whereas a hsa_circ_0072309 knockdown promoted GC cells proliferation and migration in vitro; in addition, hsa_circ_0072309 could directly bind to has-miR-34a-3p and has-miR-330-5p.

Conclusions

Hsa_circ_0072309 is a potential diagnostic biomarker for GC, and complement component 7 may be a tumor suppressor. These may potentially predict the prognosis of patients with GC and may become new therapeutic targets.

Chronotherapy: Circadian Rhythms and Their Influence in Cancer Therapy

Living organisms present rhythmic fluctuations every 24 h in their behavior and metabolism to anticipate changes in the environment. These fluctuations are controlled by a very complex molecular mechanism, the circadian clock, that regulates the expression of multiple genes to ensure the right functioning of the body. An individual's circadian system is altered during aging, and this is related to numerous age-associated pathologies and other alterations that could contribute to the development of cancer. Nowadays, there is an increasing interest in understanding how circadian rhythms could be used in the treatment of cancer. Chronotherapy aims to understand the impact that biological rhythms have on the response to a therapy to optimize its action, maximize health benefits and minimize possible adverse effects. Clinical trials so far have confirmed that optimal timing of treatment with chemo or immunotherapies could decrease drug toxicity and increase efficacy. Instead, chronoradiotherapy seems to minimize treatment-related symptoms rather than tumor progression or patient survival. In addition, potential therapeutic targets within the molecular clock have also been identified. Therefore, results of the application of chronotherapy in cancer therapy until now are challenging, feasible, and could be applied to clinical practice to improve cancer treatment without additional costs. However, different limitations and variables such as age, sex, or chronotypes, among others, should be overcome before chronotherapy can really be put into clinical practice.

Biotin receptor-targeting nanogels loaded with methotrexate for enhanced antitumor efficacy in triple-negative breast cancer in vitro and in vivo models

High-dose methotrexate (MTX) chemotherapeutic applications confront drug specificity and pharmacokinetic challenges, which can be overcome by utilizing targeted drug delivery systems. In the present study, biotin-PEG conjugated nanogels of carboxymethyl polyethyleneimine (Biotin-PEG-CMPEI) were developed for active targeted delivery of MTX in triple negative breast cancer (TNBC). TEM and DLS analyses revealed uniform, discrete, and spherical particles with a mean hydrodynamic diameter of about 100 nm and ζ-potential of + 15 mV (pH = 7.4). Biotin-PEG-CMPEI nanogels exhibited a zero-order MTX release kinetics at pH = 7.5 and a swelling-controlled release at pH = 5.5. In 4 T1 cells treated with the MTX-loaded Biotin-PEG-CMPEI, the IC₅₀ was reduced by about 10 folds compared to the free drug, while the unloaded nanogels showed no significant toxicity. In the model mice, the group treated with the MTX-loaded Biotin-PEG-CMPEI had a lower tumor volume and mortality rate animal model when compared to free drug. Additionally, histopathological analyses showed that the group treated with the MTX-loaded nanogels had less lung metastasis and glomerular damage caused by MTX. Overall, the MTX-loaded Biotin-PEG-CMPEI targeted directly against overexpressed biotin receptors in TNBC have been shown to improve the MTX safety and therapeutic efficacy.

Circadian clock synchrony and chronotherapy opportunities in cancer treatment

Cell-autonomous, tissue-specific circadian rhythms in gene expression and cellular processes have been observed throughout the human body. Disruption of daily rhythms by mistimed exposure to light, food intake, or genetic mutation has been linked to cancer development. Some medications are also more effective at certain times of day. However, a limited number of clinical studies have examined daily rhythms in the patient or drug timing as treatment strategies. This review highlights advances and challenges in cancer biology as a function of time of day. Recent evidence for daily rhythms and their entrainment in tumors indicate that personalized medicine should include understanding and accounting for daily rhythms in cancer patients.

A randomized feasibility study evaluating temozolomide circadian medicine in patients with glioma

Background

Gliomas are the most common primary brain tumor in adults. Current treatments involve surgery, radiation, and temozolomide (TMZ) chemotherapy; however, prognosis remains poor and new approaches are required. Circadian medicine aims to maximize treatment efficacy and/or minimize toxicity by timed delivery of medications in accordance with the daily rhythms of the patient. We published a retrospective study showing greater anti-tumor efficacy for the morning, relative to the evening, administration of TMZ in patients with glioblastoma. We conducted this prospective randomized trial to determine the feasibility, and potential clinical impact, of TMZ chronotherapy in patients with gliomas (NCT02781792).

Methods

Adult patients with gliomas (WHO grade II-IV) were enrolled prior to initiation of monthly TMZ therapy and were randomized to receive TMZ either in the morning (AM) before 10 am or in the evening (PM) after 8 pm. Pill diaries were recorded to measure compliance and FACT-Br quality of life (QoL) surveys were completed throughout treatment. Study compliance, adverse events (AE), and overall survival were compared between the two arms.

Results

A total of 35 evaluable patients, including 21 with GBM, were analyzed (18 AM patients and 17 PM patients). Compliance data demonstrated the feasibility of timed TMZ dosing. There were no significant differences in AEs, QoL, or survival between the arms.

Conclusions

Chronotherapy with TMZ is feasible. A larger study is needed to validate the effect of chronotherapy on clinical efficacy.

Impact of Circadian Rhythms on the Development and Clinical Management of Genitourinary Cancers

The circadian system is an innate clock mechanism that governs biological processes on a near 24-hour cycle. Circadian rhythm disruption (i.e., misalignment of circadian rhythms), which results from the lack of synchrony between the master circadian clock located in the suprachiasmatic nuclei (SCN) and the environment (i.e., exposure to day light) or the master clock and the peripheral clocks, has been associated with increased risk of and unfavorable cancer outcomes. Growing evidence supports the link between circadian disruption and increased prevalence and mortality of genitourinary cancers (GU) including prostate, bladder, and renal cancer. The circadian system also plays an essential role on the timely implementation of chronopharmacological treatments, such as melatonin and chronotherapy, to reduce tumor progression, improve therapeutic response and reduce negative therapy side effects. The potential benefits of the manipulating circadian rhythms in the clinical setting of GU cancer detection and treatment remain to be exploited. In this review, we discuss the current evidence on the influence of circadian rhythms on (disease) cancer development and hope to elucidate the unmet clinical need of defining the extensive involvement of the circadian system in predicting risk for GU cancer development and alleviating the burden of implementing anti-cancer therapies.

Molecular regulations of circadian rhythm and implications for physiology and diseases

The term “circadian rhythms” describes endogenous oscillations with ca. 24-h period associated with the earth’s daily rotation and light/dark cycle. Such rhythms reflect the existence of an intrinsic circadian clock that temporally orchestrates physiological processes to adapt the internal environment with the external cues. At the molecular level, the circadian clock consists of multiple sets of transcription factors resulting in autoregulatory transcription-translation feedback loops. Notably, in addition to their primary role as generator of circadian rhythm, the biological clock plays a key role in controlling physiological functions of almost all tissues and organs. It regulates several intracellular signaling pathways, ranging from cell proliferation, DNA damage repair and response, angiogenesis, metabolic and redox homeostasis, to inflammatory and immune response. In this review, we summarize findings showing the crosstalk between the circadian molecular clock and some key intracellular pathways, describing a scenario wherein their reciprocal regulation impinges upon several aspects of mammalian physiology. Moreover, based on evidence indicating that circadian rhythms can be challenged by environmental factors, social behaviors, as well as pre-existing pathological conditions, we discuss implications of circadian misalignment in human pathologies, such as cancer and inflammatory diseases. Accordingly, disruption of circadian rhythm has been reported to affect several physiological processes that are relevant to human diseases. Expanding our understanding of this field represents an intriguing and transversal medicine challenge in order to establish a circadian precision medicine.

Circadian Influences on Chemotherapy Efficacy in a Mouse Model of Brain Metastases of Breast Cancer

Chemotherapy is more effective in the treatment of peripheral tumors than brain metastases, likely reflecting the reduced ability of chemotherapy to cross the blood-brain barrier (BBB) and blood-tumor barrier at efficacious concentrations. Recent studies demonstrate circadian regulation of the BBB. Thus, we predicted that optimally timed chemotherapy would increase anti-tumor efficacy in a model of brain metastases of breast cancer (BMBC). First, we characterized novel daily alterations in BBB permeability to a commonly used chemotherapeutic, 14C-paclitaxel, within BMBC following injections given at four time points across the day. Peak and trough 14C-paclitaxel concentrations within BMBC occurred during the mid-dark phase and at the beginning of the light phase, respectively. Notably, chemotherapy injections during the dark phase increased cell death within BMBC and delayed onset of neurological symptoms relative to injections during the light phase. These data provide strong evidence for the beneficial effects of chrono-chemotherapy for the treatment of BMBC.

The Time for Chronotherapy in Radiation Oncology

Five decades ago, Franz Halberg conceived the idea of ​​a circadian-based therapy for cancer, given the differential tolerance to treatment derived from the intrinsic host rhythms. Nowadays, different experimental models have demonstrated that both the toxicity and efficacy of several anticancer drugs vary by more than 50% as a function of dosing time. Accordingly, it has been shown that chemotherapeutic regimens optimally timed with the circadian cycle have jointly improved patient outcomes both at the preclinical and clinical levels. Along with chemotherapy, radiation therapy is widely used for cancer treatment, but its effectiveness relies mainly on its ability to damage DNA. Notably, the DNA damage response including DNA repair, DNA damage checkpoints, and apoptosis is gated by the circadian clock. Thus, the therapeutic potential of circadian-based radiotherapy against cancer is mainly dependent upon the control that the molecular clock exerts on DNA repair enzymes across the cell cycle. Unfortunately, the time of treatment administration is not usually considered in clinical practice as it varies along the daytime working hours. Currently, only a few studies have evaluated whether the timing of radiotherapy affects the treatment outcome. Several of these studies show that it is possible to reduce the toxicity of the treatment if it is applied at a specific time range, although with some inconsistencies. In this Perspective, we review the main advances in the field of chronoradiotherapy, the possible causes of the inconsistencies observed in the studies so far and provide some recommendations for future trials.

The circadian rhythm and core gene Period2 regulate the chemotherapy effect and multidrug resistance of ovarian cancer through the PI3K signaling pathway

Background: Ovarian cancer is the most lethal cancer in the female reproductive system. It has been shown that ‘time chemotherapy’ of ovarian cancer has an important impact on the chemotherapy effect and prognosis of patients, but the specific mechanism is not known. Methods: We designed a case–control study in strict accordance with epidemiological principles. We collected resection samples of ovarian cancer patients who worked night-shifts and those who did not, and analyzed the differences in protein expression. Through construction of a normal/circadian-rhythm disorder model of ovarian cancer in nude mice, we explored the molecular mechanism of a ‘biological clock’ rhythm on treatment of ovarian cancer. Results: Expression of interleukin (IL)-6, programmed cell death receptor-1 (PD-1) and programmed death ligand 1 (PD-L1) increased, and expression of tumor necrosis factor (TNF)-α, Period 1 (Per1) and Period 2 (Per2) decreased in the night-shift group. Methylation of CpG islands in the promoter of Per2 could result in its decreased expression in SKOV3/DDP (Cisplatin) cells. Dysrhythmia of the circadian clock: (i) had a negative effect on the chemotherapy effect against ovarian cancer; (ii) affected expression of immune factors and the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. Conclusion: The Per2 gene can affect the drug resistance of ovarian cancer by inhibiting the PI3K/Akt signaling pathway and then acting on its downstream drug-resistance factors, thereby providing a new target for ovarian cancer treatment.

Circadian rhythm as a therapeutic target

The circadian clock evolved in diverse organisms to integrate external environmental changes and internal physiology. The clock endows the host with temporal precision and robust adaptation to the surrounding environment. When circadian rhythms are perturbed or misaligned, as a result of jet lag, shiftwork or other lifestyle factors, adverse health consequences arise, and the risks of diseases such as cancer, cardiovascular diseases or metabolic disorders increase. Although the negative impact of circadian rhythm disruption is now well established, it remains underappreciated how to take advantage of biological timing, or correct it, for health benefits. In this Review, we provide an updated account of the circadian system and highlight several key disease areas with altered circadian signalling. We discuss environmental and lifestyle modifications of circadian rhythm and clock-based therapeutic strategies, including chronotherapy, in which dosing time is deliberately optimized for maximum therapeutic index, and pharmacological agents that target core clock components and proximal regulators. Promising progress in research, disease models and clinical applications should encourage a concerted effort towards a new era of circadian medicine.

Clock at the Core of Cancer Development

To synchronize various biological processes with the day and night cycle, most organisms have developed circadian clocks. This evolutionarily conserved system is important in the temporal regulation of behavior, physiology and metabolism. Multiple pathological changes associated with circadian disruption support the importance of the clocks in mammals. Emerging links have revealed interplay between circadian clocks and signaling networks in cancer. Understanding the cross-talk between the circadian clock and tumorigenesis is imperative for its prevention, management and development of effective treatment options. In this review, we summarize the role of the circadian clock in regulation of one important metabolic pathway, insulin/IGF1/PI3K/mTOR signaling, and how dysregulation of this metabolic pathway could lead to uncontrolled cancer cell proliferation and growth. Targeting the circadian clock and rhythms either with recently discovered pharmaceutical agents or through environmental cues is a new direction in cancer chronotherapy. Combining the circadian approach with traditional methods, such as radiation, chemotherapy or the recently developed, immunotherapy, may improve tumor response, while simultaneously minimizing the adverse effects commonly associated with cancer therapies.

Cisplatin's dual-effect on the circadian clock triggers proliferation and apoptosis

The circadian clock, which generates the internal daily rhythm largely mediated through release of melatonin, can be disrupted in various ways. Multiple factors result in a disruption of the circadian cycle in the clinical context, of interest are anti-cancer drugs such as cisplatin. Cisplatin modulates the circadian clock through two mechanisms: 1) the circadian clock control of DNA excision repair and 2) the effect of circadian clock disruption on apoptosis. Cisplatin can stimulate multiple classified molecules, including DNA repair factors, DNA damage recognition factors and transcription factors in drug resistance and cisplatin-induced signal transduction. These factors interact with each other and can be transformed by DNA damage. Hence, these molecular interactions are intimately involved in cell proliferation and damage-induced apoptosis. Cisplatin has a dual-effect on circadian genes: upregulation of CLOCK expression causes an increase in proliferation but upregulation of BMAL1 expression causes an increase in apoptosis. Therefore, the interference of circadian genes by cisplatin can have multiple, opposing effects on apoptosis and cell proliferation, which may have unintended pro-cancer effects. Melatonin and intracellular Ca²⁺ also have a dual-effect on cell proliferation and apoptosis and can disrupt circadian rhythms.

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Cisplatin has a dual-effect on components of the circadian clock, increasing or decreasing cell proliferation and apoptosis.

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DNA excision repair and apoptosis are controlled by circadian rhythms.

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When cisplatin is combined with other agents, the effects are enhanced.

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These findings provide clinicians with the prospect to create effective chrono-cisplatin regimens for patients.

Design, Synthesis, and Antitumor Activities Study of Stapled A4K14-Citropin 1.1 Peptides

A4K14-citropin 1.1 is a structurally optimized derivative derived from amphibians' skin secreta peptide Citropin, which exhibits broad biological activities. However, the application of A4K14-citropin 1.1 as a cancer therapeutic is restricted by its structural flexibility. In this study, a series of all-hydrocarbon stapled peptides derivatives of A4K14-citropin 1.1 were designed and synthesized, and their chemical and biological characteristics were also investigated. Among them, A4K14-citropin 1.1-Sp1 and A4K14-citropin 1.1-Sp4 displayed improved helicity levels, greater protease stability, and increased antitumor activity compared with the original peptide, which establishes them as promising lead compounds for novel cancer therapeutics development. These results revealed the important influence of all-hydrocarbon stapling side chain on the secondary structure, hydrolase stability, and biological activity of A4K14-citropin 1.1.

Single cell profiling of capillary blood enables out of clinic human immunity studies

An individual’s immune system is driven by both genetic and environmental factors that vary over time. To better understand the temporal and inter-individual variability of gene expression within distinct immune cell types, we developed a platform that leverages multiplexed single-cell sequencing and out-of-clinic capillary blood extraction to enable simplified, cost-effective profiling of the human immune system across people and time at single-cell resolution. Using the platform, we detect widespread differences in cell type-specific gene expression between subjects that are stable over multiple days.

Stromal Expression of the Core Clock Gene Period 2 Is Essential for Tumor Initiation and Metastatic Colonization

The circadian clock regulates diverse physiological processes by maintaining a 24-h gene expression pattern. Genetic and environmental cues that disrupt normal clock rhythms can lead to cancer, yet the extent to which this effect is controlled by the cancer cells versus non-malignant cells in the tumor microenvironment (TME) is not clear. Here we set out to address this question, by selective manipulation of circadian clock genes in the TME. In two different mouse models of cancer we find that expression of the core clock gene Per2 in the TME is crucial for tumor initiation and metastatic colonization, whereas another core gene, Per1, is dispensable. We further show that loss of Per2 in the TME leads to significant transcriptional changes in response to cancer cell introduction. These changes may contribute to a tumor-suppressive microenvironment. Thus, our work unravels an unexpected protumorigenic role for the core clock gene Per2 in the TME, with potential implications for therapeutic dosing strategies and treatment regimens.

Time-dependent changes in proliferation, DNA damage and clock gene expression in hepatocellular carcinoma and healthy liver of a transgenic mouse model

Hepatocellular carcinoma (HCC) is highly resistant to anticancer therapy and novel therapeutic strategies are needed. Chronotherapy may become a promising approach because it may improve the efficacy of antimitotic radiation and chemotherapy by considering timing of treatment. To date little is known about time-of-day dependent changes of proliferation and DNA damage in HCC. Using transgenic c-myc/transforming growth factor (TGFα) mice as HCC animal model, we immunohistochemically demonstrated Ki67 as marker for proliferation and γ-H2AX as marker for DNA damage in HCC and surrounding healthy liver (HL). Core clock genes (Per1, Per2, Cry1, Cry2, Bmal 1, Rev-erbα and Clock) were examined by qPCR. Data were obtained from samples collected ex vivo at four different time points and from organotypic slice cultures (OSC). Significant differences were found between HCC and HL. In HCC, the number of Ki67 immunoreactive cells showed two peaks (ex vivo: ZT06 middle of day and ZT18 middle of night; OSC: CT04 and CT16). In ex vivo samples, the number of γ-H2AX positive cells in HCC peaked at ZT18 (middle of the night), while in OSC their number remained high during subjective day and night. In both HCC and HL, clock gene expression showed a time-of-day dependent expression ex vivo but no changes in OSC. The expression of Per2 and Cry1 was significantly lower in HCC than in HL. Our data support the concept of chronotherapy of HCC. OSC may become useful to test novel cancer therapies.

Spotlight on Circadian Genes and Colorectal Cancer Crosstalk

Mammalian physiology is regulated by circadian clock through oscillating feedback loops controlling cellular processes and behaviors. Recent findings have led to an interesting connection between circadian disruption and colorectal cancer progression and incidence through controlling the hallmarks of cancer, namely cell cycle, cell metabolism and cell death. Deeper understanding of the circadian mechanisms that define the colorectal cancer pathophysiology is the need of the hour to define a chronotherapy for improving colorectal cancer patient survival. This review identifies the key areas in which circadian genes interact with cellular pathways to modify the outcome with respect to colorectal cancer incidence and progression.

Cancer and the Circadian Clock

The circadian clock is a master regulator of mammalian physiology, regulating daily oscillations of crucial biological processes and behaviors. Notably, circadian disruption has recently been identified as an independent risk factor for cancer and classified as a carcinogen. As such, it is imperative to discern the underpinning mechanisms by which circadian disruption alters cancer risk. Emergent data, reviewed herein, demonstrate that circadian regulatory functions play critical roles in several hallmarks of cancer, including control of cell proliferation, cell death, DNA repair, and metabolic alteration. Developing a deeper understanding of circadian-cancer regulation cross-talk holds promise for developing new strategies for cancer interception, prevention, and management.

Expression of Circadian Clock Genes in Human Colorectal Cancer Tissues Using Droplet Digital PCR

Increasing evidence indicates that disruption of circadian rhythms may be directly linked to cancer. Here we report that the expression levels of the core clock genes Per1 and Per3 measured by droplet digital polymerase chain reaction are significantly decreased in tumour tissue from 16 patients undergoing colorectal cancer surgery compared to paired normal mucosa. No differences were observed in the expression of Per2, Bmal1, and Clock. In conclusion, abnormal expression levels of the clock genes Per1 and Per3 in CRC tissue may be related to tumourigenesis and may provide future diagnostic and prognostic information.

Reducing Hospital Toxicity: Impact on Patient Outcomes

BACKGROUND

Circadian rhythms are endogenous 24-hour oscillations in biologic processes that drive nearly all physiologic and behavioral functions. Disruption in circadian rhythms can adversely impact short- and long-term health outcomes. Routine hospital care often causes significant disruption in sleep-wake patterns that is further compounded by loss of personal control of health information and health decisions. We wished to evaluate measures directed at improving circadian rhythm and access to daily health information on hospital outcomes.

METHODS

We evaluated 3425 consecutive patients admitted to a medical-surgical unit comprised of an intervention wing (n = 1185) or standard control wing (n = 2240) over a 2.5-year period. Intervention patients received measures to improve sleep that included reduction of nighttime noise, delay of routine morning phlebotomy, passive vital sign monitoring, and use of red-enriched lighting after sunset, as well as access to daily health information utilizing an inpatient portal.

RESULTS

Intervention patients accessed the inpatient portal frequently during hospitalization seeking personal health and care team information. Measures impacting the quality and quantity of sleep were significantly improved. Length of stay was 8.6hours less (P = .04), 30- and 90-day readmission rates were 16% and 12% lower, respectively (both P ≤ .02), and self-rated emotional/mental health was higher (69.2% vs 52.4%; P = 0.03) in the intervention group compared with controls.

CONCLUSIONS

Modest changes in routine hospital care can improve the hospital environment impacting sleep and access to health knowledge, leading to improvements in hospital outcomes. Sleep-wake patterns of hospitalized patients represent a potential avenue for further enhancing hospital quality and safety.

Training the Circadian Clock, Clocking the Drugs, and Drugging the Clock to Prevent, Manage, and Treat Chronic Diseases

Daily rhythms in behavior, physiology, and metabolism are an integral part of homeostasis. These rhythms emerge from interactions between endogenous circadian clocks and ambient light-dark cycles, sleep-activity cycles, and eating-fasting cycles. Nearly the entire primate genome shows daily rhythms in expression in tissue- and locus-specific manners. These molecular rhythms modulate several key aspects of cellular and tissue function with profound implications in public health, disease prevention, and disease management. In modern societies light at night disrupts circadian rhythms, leading to further disruption of sleep-activity and eating-fasting cycles. While acute circadian disruption may cause transient discomfort or exacerbate chronic diseases, chronic circadian disruption can enhance risks for numerous diseases. The molecular understanding of circadian rhythms is opening new therapeutic frontiers placing the circadian clock in a central role. Here, we review recent advancements on how to enhance our circadian clock through behavioral interventions, timing of drug administration, and pharmacological targeting of circadian clock components that are already providing new preventive and therapeutic strategies for several diseases, including metabolic syndrome and cancer.

WOMEN IN CANCER THEMATIC REVIEW: Circadian rhythmicity and the influence of 'clock' genes on prostate cancer

The androgen receptor (AR) plays a key role in the development and progression of prostate cancer (CaP). Since the mid-1990s, reports in the literature pointed out higher incidences of CaP in some select groups, such as airline pilots and night shift workers in comparison with those working regular hours. The common finding in these 'high-risk' groups was that they all experienced a deregulation of the body's internal circadian rhythm. Here, we discuss how the circadian rhythm affects androgen levels and modulates CaP development and progression. Circadian rhythmicity of androgen production is lost in CaP patients, with the clock genes Per1 and Per2 decreasing, and Bmal1 increasing, in these individuals. Periodic expression of the clock genes was restored upon administration of the neurohormone melatonin, thereby suppressing CaP progression. Activation of the melatonin receptors and the AR antagonized each other, and therefore the tumour-suppressive effects of melatonin and the clock genes were most clearly observed in the absence of androgens, that is, in conjunction with androgen deprivation therapy (ADT). In addition, a large-scale study found that high-dose radiation was more effective in CaP patients when it was delivered before 17:00 h, compared with those delivered after 17:00 h, suggesting that the therapy was more effective when delivered in synchrony with the patient's circadian clock. As CaP patients are shown to become easily resistant to new therapies, perhaps circadian delivery of these therapeutic agents or delivery in conjunction with melatonin and its novel analogs should be tested to see if they prevent this resistance.

Clinical Aspects of Human Circadian Rhythms

Circadian rhythmicity can be important in the pathophysiology, diagnosis, and treatment of clinical disease. Due to the difficulties in conducting the necessary experimental work, it remains unknown whether ~24-h changes in pathophysiology or symptoms of many diseases are causally linked to endogenous circadian rhythms or to other diurnal factors that change across the day, such as changes in posture, activity, sleep or wake state, or metabolic changes associated with feeding or fasting. Until the physiology is accurately known, appropriate treatment cannot be designed. This review includes an overview of clinical disorders that are caused or affected by circadian or diurnal rhythms. The clinical side effects of disruption of circadian rhythmicity, such as in shiftwork, including the public health implications of the disrupted alertness and performance, are also discussed.

Chronotherapy in practice: the perspective of the community pharmacist

BACKGROUND

Optimising the time of drug administration in alignment with circadian rhythms to enhance the clinical effect or minimise/avoid adverse effects is referred to as chronotherapy. Pharmacists have a key role in providing medicine related information, including counselling about the optimal time for medication administration. Where applicable, the principles of chronotherapy should underlie this aspect of medication counselling. Despite significant developments in the science of chronotherapy for specific pharmacological treatments, the perspective of pharmacists about their understanding and application of these principles in practice has not been explored.

OBJECTIVE

To explore community pharmacist's viewpoints about and experience with the application of chronotherapy principles in practice.

SETTING

Community pharmacies within metropolitan Sydney in New South Wales, Australia.

METHODS

Semi-structured, face to face interviews with a convenience sample of community pharmacists were conducted. All interviews were audio-recorded, transcribed verbatim and thematically analyzed using a 'grounded theory' approach, given the novelty of this area. Main outcome measure Community pharmacists' awareness, current practice and future practice support requirements about the principles of chronotherapy.

RESULTS

Twenty-five semi-structured interviews were conducted. Most participants reported encountering cases where clinical decision making about suggesting appropriate times of drug administration to patients was needed. Their approach was mainly pragmatic rather than based on theoretical principles of circadian variation in drug disposition or on current or emerging evidence; thus there was an evidence practice chasm in some cases. However, most participants believed they have an important role to play in counselling patients about optimal administration times and were willing to enact such roles or acquire skills/competence in this area.

CONCLUSION

Community pharmacists contribute to the safe and effective use of medications in providing the patients with information on optimal timing of drug administration during counselling. Further education, practical training and access to information may help pharmacists in translating principles of chronotherapy into the practice.

Circadian Clocks in the Hematologic System

The hematologic system performs a number of essential functions, including oxygen transport, the execution of the immune response against tumor cells and invading pathogens, and hemostasis (blood clotting). These roles are performed by erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets), respectively. Critically, circadian rhythms are evident in the function of all 3 cell types. In this review, we describe these oscillations, explore their mechanistic bases, and highlight their key implications. Since erythrocytes are anucleate, circadian rhythms in these cells testify to the existence of a nontranscriptional circadian clock. From a clinical perspective, leukocyte rhythms could underlie daily variation in the severity of allergic reactions, the symptoms of chronic inflammatory diseases, and the body’s response to infection, while the rhythmic properties of thrombocytes may explain daily fluctuations in the incidence of heart attack and stroke. Consequently, the efficacy of treatments for these conditions is likely to depend on the timing of their administration. Last, we outline preliminary evidence that circadian disruption in the hematologic system could contribute to the deleterious effects of poor diet, shift work, and alcohol abuse on human health.

Advancing the delivery of anticancer drugs: Conjugated polymer/triterpenoid composite

Exemplifying the synergy of anticancer properties of triterpenoids and ion retention qualities of conjugated polymers, we propose a conducting matrix to be a reservoir of anticancer compounds. In this study, poly(3,4-ethylenedioxythiophene), PEDOT, based matrix for electrically triggered and local delivery of the ionic form of anticancer drug, oleanolic acid (HOL), has been investigated. An initial, one-step fabrication procedure has been proposed, providing layers exhibiting good drug release properties and biological activity. Investigation of obtained systems and implementation of modifications revealed another route of fabrication. This procedure was found to yield layers possessing a significantly greater storage capacity of OL(-), as evidenced by the 52% increase in the drug concentrations attainable through electro-assisted release. Examination of the biological activity of immobilised and released OL(-) molecules proved that electrochemical treatment has negligible impact on the anticancer properties of OL(-), particularly when employing the three-step procedure, in which the range of applied potentials is limited. PEDOT/OL(-) composite has been demonstrated to be a robust and cost-effective material for controlled drug delivery.

Circadian Clock Gene CRY2 Degradation Is Involved in Chemoresistance of Colorectal Cancer

Biomarkers for predicting chemotherapy response are important to the treatment of colorectal cancer patients. Cryptochrome 2 (CRY2) is a circadian clock protein involved in cell cycle, but the biologic consequences of this activity in cancer are poorly understood. We set up biochemical and cell biology analyses to analyze CRY2 expression and chemoresistance. Here, we report that CRY2 is overexpressed in chemoresistant colorectal cancer samples, and CRY2 overexpression is correlated with poor patient survival. Knockdown of CRY2 increased colorectal cancer sensitivity to oxaliplatin in colorectal cancer cells. We also identify FBXW7 as a novel E3 ubiquitin ligase for targeting CRY2 through proteasomal degradation. Mechanistic studies show that CRY2 is regulated by FBXW7, in which FBXW7 binds directly to phosphorylated Thr300 of CRY2. Furthermore, FBXW7 expression leads to degradation of CRY2 through enhancing CRY2 ubiquitination and accelerating the CRY2's turnover rate. High FBXW7 expression downregulates CRY2 and increases colorectal cancer cells' sensitivity to chemotherapy. Low FBXW7 expression is correlated with high CRY2 expression in colorectal cancer patient samples. Also, low FBXW7 expression is correlated with poor patient survival. Taken together, our findings indicate that the upregulation of CRY2 caused by downregulation of FBXW7 may be a novel prognostic biomarker and may represent a new therapeutic target in colorectal cancer.

Inhibition effect of a custom peptide on lung tumors

Cecropin B is a natural antimicrobial peptide and CB1a is a custom, engineered modification of it. In vitro, CB1a can kill lung cancer cells at concentrations that do not kill normal lung cells. Furthermore, in vitro, CB1a can disrupt cancer cells from adhering together to form tumor-like spheroids. Mice were xenografted with human lung cancer cells; CB1a could significantly inhibit the growth of tumors in this in vivo model. Docetaxel is a drug in present clinical use against lung cancers; it can have serious side effects because its toxicity is not sufficiently limited to cancer cells. In our studies in mice: CB1a is more toxic to cancer cells than docetaxel, but dramatically less toxic to healthy cells.

The epigenetic language of circadian clocks

Epigenetic control, which includes DNA methylation and histone modifications, leads to chromatin remodeling and regulated gene expression. Remodeling of chromatin constitutes a critical interface of transducing signals, such as light or nutrient availability, and how these are interpreted by the cell to generate permissive or silenced states for transcription. CLOCK-BMAL1-mediated activation of clock-controlled genes (CCGs) is coupled to circadian changes in histone modification at their promoters. Several chromatin modifiers, such as the deacetylases SIRT1 and HDAC3 or methyltransferase MLL1, have been shown to be recruited to the promoters of the CCGs in a circadian manner. Interestingly, the central element of the core clock machinery, the transcription factor CLOCK, also possesses histone acetyltransferase activity. Rhythmic expression of the CCGs is abolished in the absence of these chromatin modifiers. Here we will discuss the evidence demonstrating that chromatin remodeling is at the crossroads of circadian rhythms and regulation of metabolism and cellular proliferation.