Clock gene Per2 as a controller of liver carcinogenesis

Environmental disruption of molecular clocks promoted liver carcinogenesis and accelerated cancer progression in rodents. We investigated the specific role of clock gene Period 2 (Per2) for liver carcinogenesis and clock-controlled cellular proliferation, genomic instability and inflammation. We assessed liver histopathology, and determined molecular and physiology circadian patterns in mice on chronic diethylnitrosamine (DEN) exposure according to constitutive Per2 mutation. First, we found that Per2^m/m liver displayed profound alterations in proliferation gene expression, including c-Myc derepression, phase-advanced Wee1, and arrhythmic Ccnb1 and K-ras mRNA expressions, as well as deregulated inflammation, through arrhythmic liver IL-6 protein concentration, in the absence of any DEN exposure. These changes could then make Per2^m/m mice more prone to subsequently develop liver cancers on DEN. Indeed, primary liver cancers were nearly fourfold as frequent in Per2^m/m mice as compared to wild-type (WT), 4 months after DEN exposure. The liver molecular clock was severely disrupted throughout the whole carcinogenesis process, including the initiation stage, i.e. within the initial 17 days on DEN. Per2^m/m further exhibited increased c-Myc and Ccnb1 mean 24h expressions, lack of P53 response, and arrhythmic ATM, Wee1 and Ccnb1 expressions. DEN-induced tumor related inflammation was further promoted through increased protein concentrations of liver IL-6 and TNF-α as compared to WT during carcinogenesis initiation. Per2 mutation severely deregulated liver gene or protein expressions related to three cancer hallmarks, including uncontrolled proliferation, genomic instability, and tumor promoting inflammation, and accelerated liver carcinogenesis several-fold. Clock gene Per2 acted here as a liver tumor suppressor from initiation to progression.

The immune system as a chronotoxicity target of the anticancer mTOR inhibitor everolimus

The circadian timing system controls many biological functions in mammals including xenobiotic metabolism, detoxification, cell proliferation, apoptosis and immune functions. Everolimus is a mammalian target of rapamycin inhibitor, whose immunosuppressant properties are both desired in transplant patients and unwanted in cancer patients, where it is indicated for its antiproliferative efficacy. Here we sought whether everolimus circadian timing would predictably modify its immunosuppressive effects so as to optimize this drug through timing. C57BL/6J mice were synchronized with light-dark 12h:12h, with L onset at Zeitgeber Time (ZT) 0. Everolimus was administered orally to male (5 mg/kg/day) and female mice (15 mg/kg/day) at ZT1, during early rest span or at ZT13, during early activity span for 4 weeks. Body weight loss, as well as hematological, immunological and biochemical toxicities, were determined. Spleen and thymus were examined histologically. Everolimus toxicity was less severe following dosing at ZT13, as compared to ZT1, as shown with least body weight inhibition in both genders; least reductions in thymus weight both in males (p < 0.01) and females (p < 0.001), least reduction in female spleen weight (p < 0.05), and less severe thymic medullar atrophy both in males (p < 0.001) and females (p < 0.001). The mean circulating counts in total leukocytes, total lymphocytes, T-helper and B lymphocytes displayed minor and non-significant changes following dosing at ZT13, while they were decreased by 56.9% (p < 0.01), 45.5% (p < 0.01), 43.1% (p < 0.05) and 48.7% (p < 0.01) after everolimus at ZT1, respectively, in only male mice. Chronotherapy of everolimus is an effective way to increase the general tolerability and decrease toxicity on the immune system.

Pharmacokinetics of Irinotecan, Oxaliplatin and 5-Fluorouracil During Hepatic Artery Chronomodulated Infusion: A Translational European OPTILIV Study

The combination of hepatic artery infusion (HAI) of irinotecan, 5-fluorouracil and oxaliplatin with intravenous cetuximab has safely achieved prolonged survival in colorectal cancer patients with extensive liver metastases and prior treatment. Systemic exposure to the drugs or their main metabolites was determined during the first course of chronomodulated triplet HAI in 11 patients and related to toxicities after one or three courses. Consistent trends were found between the area under the plasma concentration-time curve (AUC) values of irinotecan, 7-ethyl-10-hydroxycamptothecin (SN38; a bioactive metabolite), total oxaliplatin and platinum ultrafiltrate (P-UF), on the one hand, and subsequent leukopenia severity, on the other hand. Moreover, the maximum plasma concentration (C _max) and the AUC of P-UF significantly predicted grades of diarrhoea (p = 0.004 and 0.017, respectively) and anaemia (p = 0.001 and 0.008, respectively) after the first course. Systemic drug exposure helps explain both the adverse events and the low rate of extrahepatic progression-a usual drawback of HAI chemotherapy-thus supporting upfront testing of the regimen. Systems optimization of chronomodulated HAI delivery could further reduce adverse events.

Pharmacogenetic determinants of outcomes on triplet hepatic artery infusion and intravenous cetuximab for liver metastases from colorectal cancer (European trial OPTILIV, NCT00852228)

Background:

The hepatic artery infusion (HAI) of irinotecan, oxaliplatin and 5-fluorouracil with intravenous cetuximab achieved outstanding efficacy in previously treated patients with initially unresectable liver metastases from colorectal cancer. This planned study aimed at the identification of pharmacogenetic predictors of outcomes.

Methods:

Circulating mononuclear cells were analysed for 207 single-nucleotide polymorphisms (SNPs) from 34 pharmacology genes. Single-nucleotide polymorphisms passing stringent Hardy–Weinberg equilibrium test were tested for their association with outcomes in 52 patients (male/female, 36/16; WHO PS, 0–1).

Results:

VKORC1 SNPs (rs9923231 and rs9934438) were associated with early and objective responses, and survival. For rs9923231, T/T achieved more early responses than C/T (50% vs 5%, P=0.029) and greatest 4-year survival (46% vs 0%, P=0.006). N-acetyltransferase-2 (rs1041983 and rs1801280) were associated with up to seven-fold more macroscopically complete hepatectomies. Progression-free survival was largest in ABCB1 rs1045642 T/T (P=0.026) and rs2032582 T/T (P=0.035). Associations were found between toxicities and gene variants (P<0.05), including neutropenia with ABCB1 (rs1045642) and SLC0B3 (rs4149117 and rs7311358); and diarrhoea with CYP2C9 (rs1057910), CYP2C19 (rs3758581), UGT1A6 (rs4124874) and SLC22A1 (rs72552763).

Conclusion:

VKORC1, NAT2 and ABCB1 variants predicted for HAI efficacy. Pharmacogenetics could guide the personalisation of liver-targeted medico-surgical therapies.

Relationship between subjective and actigraphy-measured sleep in 237 patients with metastatic colorectal cancer

OBJECTIVE

Patients with cancers frequently experience sleep and circadian dysfunction. To date, only a few studies have used both a questionnaire and actigraphy for concomitant evaluation of sleep and circadian function in patients with cancer. We sought to evaluate objective sleep and circadian parameters in metastatic colon cancer (MCC) patients and their associations with symptoms and quality of life (QOL).

METHODS

Patients reported subjective sleep problems on the EORTC QLQ-C30. Sleep and circadian parameters were calculated using a wrist-actigraph that patients wore for 72 h.

RESULTS

237 Patients with MCC (mean age: 60.4 years; range: 20.7-77.6; Male/Female ratio: 1.66) participated in this cross-sectional study. Subjective sleep problems were reported by 63.4% of patients (S+). No differences in any sleep parameters (sleep efficiency, sleep latency, total sleep time, total time in bed, wake after sleep onset, activity bathyphase) were observed between S+ and S- patients. However, S+ patients displayed a significantly worse circadian function than S- patients (96.4 vs 98.1%; p = 0.005). The presence of poor subjective sleep and objective circadian dysfunction negatively affected symptoms and QOL domains (p = 0.038).

CONCLUSIONS

Subjective report of sleep problems was not associated with worse objectively measured sleep parameters in patients with MCC although it was associated with disrupted circadian rest-activity rhythm and poorer QOL. These findings coincide with prior research in cancer patients in that an inconsistent relationship exists between subjective and objective sleep measurements on some sleep domains. This study supports the value of coupled evaluation of self-reported and objective measures of sleep and circadian function in cancer patients.

Critical cholangiocarcinogenesis control by cryptochrome clock genes

A coordinated network of molecular circadian clocks in individual cells generates 24-hr rhythms in liver metabolism and proliferation. Circadian disruption through chronic jet lag or Per2 clock gene mutation was shown to accelerate hepatocarcinoma development in mice. As divergent effects were reported for clock genes Per and Cry regarding xenobiotic toxicity, we questioned the role of Cry1 and Cry2 in liver carcinogenesis. Male WT and Cry1^-/- Cry2^-/- mice (C57Bl/6 background) were chronically exposed to diethylnitrosamine (DEN) at ZT11. Rest-activity and body temperature rhythms were monitored using an implanted radiotransmitter. Serum aspartate and alanine aminotransferases (AST and ALT) were determined on four occasions during the progression stage. After 7 months, serum alkaline phosphatases (ALP) were determined, and livers were sampled for microscopic tumor nodule counting and histopathology. Five months after initiation of DEN treatment, we found that Cry1^-/- Cry2^-/- mice developed severe liver dysplasia, as evident from the increased AST, ALT and ALP levels, as compared to WT mice. DEN exposure induced primary liver cancers in nearly fivefold as many Cry1^-/- Cry2^-/- mice as compared to WT mice (p = 0.01). Microscopic study revealed no difference in the average number of hepatocarcinomas and a nearly eightfold increase in the average number of cholangiocarcinomas in Cry1^-/- Cry2^-/- mice, as compared to WT mice. This study validated the hypothesis that molecular circadian clock disruption dramatically increased chemically induced liver carcinogenesis. In addition, the pronounced shift toward cholangiocarcinoma in DEN exposed Cry1^-/- Cry2^-/- mice revealed a critical role of the Cry clock genes in bile duct carcinogenesis.

Early tumour response as a survival predictor in previously- treated patients receiving triplet hepatic artery infusion and intravenous cetuximab for unresectable liver metastases from wild-type KRAS colorectal cancer

BACKGROUND

Early tumour shrinkage has been associated with improved survival in patients receiving cetuximab-based systemic chemotherapy for liver metastases from colorectal cancer (LM-CRC). We tested this hypothesis for previously treated LM-CRC patients receiving cetuximab (500 mg/m²) and triplet hepatic artery infusion (HAI) within European trial OPTILIV.

METHODS

Irinotecan (180 mg/m²), 5-fluorouracil (2800 mg/m²) and oxaliplatin (85 mg/m²) were given as chronomodulated or conventional delivery. Patients were retrospectively categorised as early responders (complete or partial RECIST response after three courses) or non-early responders (late or no response). Prognostic factors were determined using multivariate logistic or Cox regression models.

RESULTS

Response was assessed in 57 of 64 registered patients (89%), who had previously received one to three prior systemic chemotherapy protocols. An early response occurred at 6 weeks in 16 patients (28%; 9 men, 7 women), aged 33-76 years, with a median of 12 liver metastases (LMs) (2-50), involving five segments (1-8). Ten patients had a late response, and 31 patients had no response. Grade 3-4 fatigue selectively occurred in the non-early responders (0% versus 26%; p = 0.024). Early tumour response was jointly predicted by chronomodulation-odds ratio (OR): 6.0 (1.2-29.8; p = 0.029)-and LM diameter ≤57 mm-OR: 5.3 (1.1-25.0; p = 0.033). Early tumour response predicted for both R0-R1 liver resection-OR: 11.8 (1.4-100.2; p = 0.024) and overall survival-hazard ratio: 0.39 (0.17-0.88; p = 0.023) in multivariate analyses.

CONCLUSIONS

Early tumour response on triplet HAI and systemic cetuximab predicted for complete macroscopic liver resection and prolonged survival for LM-CRC patients within a multicenter conversion-to-resection medicosurgical strategy. Confirmation is warranted for early response on HAI to guide decision making. Protocol numbers: EUDRACT 2007-004632-24 NCT00852228.

Circadian Physiology Is a Toxicity Target of the Anticancer Drug Gemcitabine in Mice

The circadian timing system determines the optimal timing and waveform of drug tolerability, yet treatment itself can alter this system. Gemcitabine is an antimetabolite agent that is active against lung and pancreatic cancers. Tolerability for this drug is best following dosing at ZT 11 in mice. The authors investigated the effects of gemcitabine on the circadian rhythms in body temperature and rest activity as physiological markers of the circadian timing system. Healthy unrestrained B6D2F1 mice implanted with radiotelemetry transmitters were kept in LD 12:12 prior to receiving a single intravenous dose of gemcitabine (200, 400, or 600 mg/kg) at ZT 11 or 23. Gemcitabine (400 mg/kg) transiently suppressed the body temperature rhythm in 50% of the mice dosed at ZT 23, as compared to none of the mice treated at ZT 11 within the 2 days following drug dosing (Fisher 's exact test p = 0.04). The rest-activity circadian rhythm was suppressed in 40% (ZT 11) and 50% (ZT 23) of the mice, respectively. In the mice with persistent circadian rhythms, gemcitabine delivery at ZT 23 resulted in more prominent decreases and slower recovery of circadian mesor and amplitude of both rhythms as compared to mice treated at ZT 11. Gemcitabine also induced a transient internal desynchronization between temperature and activity rhythms following dosing at ZT 23 but not at ZT 11. The delivery of a single therapeutic dose of gemcitabine near its time of least toxicity produced least alterations in circadian physiological outputs, a finding that suggests that the extent of circadian disruption contributes to toxicokinetic processes.

The difference between in bed and out of bed activity as a behavioral marker of cancer patients: A comparative actigraphic study

The current study was conducted to provide normative data on actigraphic dichotomy index (I < O) (the percentage of in bed activity counts that are less than the median of out of bed counts) in healthy population and to assess whether the I < O could be an effective index in discriminating the circadian motor activity of cancer patients from healthy controls. In this retrospective study, we recovered 408 actigraphic records from two databases: healthy controls (n = 182; 79 males; mean age 38.7 ± 12.6) and patients with metastatic colorectal cancer (n = 226; 149 males; mean age 58.4 ± 11.4). Beside the usual actigraphic sleep parameters (time in bed, sleep onset latency, total sleep time, wake after sleep onset, sleep efficiency, number of awakenings, and mean motor activity), we also computed the dichotomy index and number of actigraphic wake parameters, namely, diurnal motor activity, diurnal total sleep time, number of sleep episodes, and the mean duration of the longest diurnal sleep episode. Using the Youden index, we calculated the cut off value that performed the best for I < O and actigraphic wake parameters. Finally, we created Receiver Operator Characteristic curves to test the efficacy of each actigraphic parameter to discriminate cancer patient from healthy controls. Mean I < O was 99.5% (SD, 0.48%) in the healthy group, as compared to 96.6% (SD, 3.6%) in the cancer group (p < 0.0001). Important age-related effects appeared unlikely after performing both the main analysis with age as a covariate, and a subset analysis in 104 subjects matched for age and sex. In the main analysis, all actigraphic parameters, except total sleep time, significantly differentiated the two groups of participants. However, the I < O was the one that clearly performed best. Here, we provide the first large dataset on I < O in healthy subjects, we confirm the relevance of this circadian index for discriminating advanced stage colorectal cancer patients from healthy subjects, and we lay the grounds for further investigations of this circadian index in patients with other chronic diseases.

Relevance of internal time and circadian robustness for cancer patients

BACKGROUND

Adequate circadian timing of cancer treatment schedules (chronotherapy) can enhance tolerance and efficacy several-fold in experimental and clinical situations. However, the optimal timing varies according to sex, genetic background and lifestyle. Here, we compute the individual phase of the Circadian Timing System to decipher the internal timing of each patient and find the optimal treatment timing.

METHODS

Twenty-four patients (11 male; 13 female), aged 36 to 77 years, with advanced or metastatic gastro-intestinal cancer were recruited. Inner wrist surface Temperature, arm Activity and Position (TAP) were recorded every 10 min for 12 days, divided into three 4-day spans before, during and after a course of a set chronotherapy schedule. Pertinent indexes, I < O and a new biomarker, DI (degree of temporal internal order maintenance), were computed for each patient and period.

RESULTS

Three circadian rhythms and the TAP rhythm grew less stable and more fragmented in response to treatment. Furthermore, large inter- and intra-individual changes were found for T, A, P and TAP patterns, with phase differences of up to 12 hours among patients. A moderate perturbation of temporal internal order was observed, but the administration of fixed chronomodulated chemotherapy partially resynchronized temperature and activity rhythms by the end of the study.

CONCLUSIONS

The integrated variable TAP, together with the asynchrony among rhythms revealed by the new biomarker DI, would help in the personalization of cancer chronotherapy, taking into account individual circadian phase markers.

Dosing-Time Makes the Poison: Circadian Regulation and Pharmacotherapy

Daily rhythms in physiology significantly modulate drug pharmacokinetics and pharmacodynamics according to the time-of-day, a finding that has led to the concept of chronopharmacology. The importance of biological clocks for xenobiotic metabolism has gained increased attention with the discovery of the molecular circadian clockwork. Mechanistic understanding of the cell-autonomous molecular circadian oscillator and the circadian timing system as a whole has opened new conceptual and methodological lines of investigation to understand first, the clock's impact on a specific drug's daily variations or the effects/side effects of environmental substances, and second, how clock-controlled pathways are coordinated within a given tissue or organism. Today, there is an increased understanding of the circadian modulation of drug effects. Moreover, several molecular strategies are being developed to treat disease-dependent and drug-induced clock disruptions in humans.

Identification of Circadian Determinants of Cancer Chronotherapy through In Vitro Chronopharmacology and Mathematical Modeling

Cancer chronotherapy aims at enhancing tolerability and efficacy of anticancer drugs through their delivery according to circadian clocks. However, mouse and patient data show that lifestyle, sex, genetics, drugs, and cancer can modify both host circadian clocks and metabolism pathways dynamics, and thus the optimal timing of drug administration. The mathematical modeling of chronopharmacology could indeed help moderate optimal timing according to patient-specific determinants. Here, we combine in vitro and in silico methods, in order to characterize the critical molecular pathways that drive the chronopharmacology of irinotecan, a topoisomerase I inhibitor with complex metabolism and known activity against colorectal cancer. Large transcription rhythms moderated drug bioactivation, detoxification, transport, and target in synchronized colorectal cancer cell cultures. These molecular rhythms translated into statistically significant changes in pharmacokinetics and pharmacodynamics according to in vitro circadian drug timing. The top-up of the multiple coordinated chronopharmacology pathways resulted in a four-fold difference in irinotecan-induced apoptosis according to drug timing. Irinotecan cytotoxicity was directly linked to clock gene BMAL1 expression: The least apoptosis resulted from drug exposure near BMAL1 mRNA nadir (P < 0.001), whereas clock silencing through siBMAL1 exposure ablated all the chronopharmacology mechanisms. Mathematical modeling highlighted circadian bioactivation and detoxification as the most critical determinants of irinotecan chronopharmacology. In vitro-in silico systems chronopharmacology is a new powerful methodology for identifying the main mechanisms at work in order to optimize circadian drug delivery.

The effect of circadian rhythm on pharmacokinetics and metabolism of the Cdk inhibitor, roscovitine, in tumor mice model

Roscovitine is a selective Cdk-inhibitor that is under investigation in phase II clinical trials under several conditions, including chemotherapy. Tumor growth inhibition has been previously shown to be affected by the dosing time of roscovitine in a Glasgow osteosarcoma xenograft mouse model. In the current study, we examined the effect of dose timing on the pharmacokinetics, biodistribution and metabolism of this drug in different organs in B6D2F1 mice. The drug was orally administered at resting (ZT3) or activity time of the mice (ZT19) at a dose of 300 mg/kg. Plasma and organs were removed at serial time points (10, 20 and 30 min; 1, 2, 4, 6, 8, 12 and 24 h) after the administration. Roscovitine and its carboxylic metabolite concentrations were analyzed using HPLC-UV, and pharmacokinetic parameters were calculated in different organs. We found that systemic exposure to roscovitine was 38% higher when dosing at ZT3, and elimination half-life was double compared to when dosing at ZT19. Higher organ concentrations expressed as (organ/plasma) ratio were observed when dosing at ZT3 in the kidney (180%), adipose tissue (188%), testis (132%) and lungs (112%), while the liver exposure to roscovitine was 120% higher after dosing at ZT19. The metabolic ratio was approximately 23% higher at ZT19, while the intrinsic clearance (CLint) was approximately 67% higher at ZT19, indicating faster and more efficient metabolism. These differences may be caused by circadian differences in the absorption, distribution, metabolism and excretion processes governing roscovitine disposition in the mice. In this article, we describe for the first time the chronobiodistribution of roscovitine in the mouse and the contribution of the dosing time to the variability of its metabolism. Our results may help in designing better dosing schedules of roscovitine in clinical trials.

Wrist actimetry circadian rhythm as a robust predictor of colorectal cancer patients survival

The disruption of the circadian timing system (CTS), which rhythmically controls cellular metabolism and proliferation, accelerated experimental cancer progression. A measure of CTS function in cancer patients could thus provide novel prediction information for outcomes, and help to identify novel specific therapies. The rest-activity circadian rhythm is a reliable and non-invasive CTS biomarker, which was monitored using a wrist watch accelerometer for 2 days in 436 patients with metastatic colorectal cancer. The relative percentage of activity in-bed versus out-of-bed (I < O) constituted the tested CTS measure, whose prognostic value for overall survival (OS) and progression-free survival (PFS) was determined in a pooled analysis of three patient cohorts with different treatment exposures. Median OS was 21.6 months [17.8-25.5] for patients with I < O above the median value of 97.5% as compared to 11.9 months [10.4-13.3] for those with a lower I < O (Log-rank p < 0.001). Multivariate analyses retained continuous I < O as a joint predictor of both OS and PFS, with respective hazard ratios (HR) of 0.954 (p < 0.001) and 0.970 (p < 0.001) for each 1% increase in I < O. HRs had similar values in all the patient subgroups tested. The circadian physiology biomarker I < O constitutes a robust and independent quantitative predictor of cancer patient outcomes, that can be easily and cost-effectively measured during daily living. Interventional studies involving 24-h schedules of clock-targeted drugs, light intensity, exercise and/or meals are needed for testing the relevance of circadian synchronization for the survival of patients with disrupted rhythms.

Functional genomics identify Birc5/survivin as a candidate gene involved in the chronotoxicity of cyclin-dependent kinase inhibitors

The circadian timing system orchestrates most of mammalian physiology and behavior in synchrony with the external light/dark cycle. This regulation is achieved through endogenous clocks present in virtually all body cells, where they control key cellular processes, including metabolism, transport, and the cell cycle. Consistently, it has been observed in preclinical cancer models that both the efficacy and toxicity of most chemotherapeutic drugs depend on their time of administration. To further explore the molecular basis underlying the link between the circadian timing system and the cellular response to anticancer drugs, we investigated the circadian transcriptome and CDK inhibitor toxicity in colon mucosa cells. We first show here that among 181 circadian transcripts, approximately 30% of them drive the cell cycle in the healthy mouse colon mucosa, with a majority peaking during the early resting phase. The identification of 26 mitotic genes within this cluster further indicated that the transcriptional coordination of mitosis by the circadian clock participates in the gating of cell division in this tissue. Subsequent selective siRNA-mediated silencing of these 26 targets revealed that low expression levels of the mitotic and anti-apoptotic gene Birc5/survivin significantly and specifically increased the sensitivity of colon epithelial cells to CDK inhibitors. By identifying Birc5/survivin as a potential determinant for the circadian modulation of CDK inhibitor toxicity, these data provide a mechanistic basis for the preclinical development of future CDK inhibitor-based chronotherapeutic strategies.

A circadian clock transcription model for the personalization of cancer chronotherapy

Circadian timing of anticancer medications has improved treatment tolerability and efficacy several fold, yet with intersubject variability. Using three C57BL/6-based mouse strains of both sexes, we identified three chronotoxicity classes with distinct circadian toxicity patterns of irinotecan, a topoisomerase I inhibitor active against colorectal cancer. Liver and colon circadian 24-hour expression patterns of clock genes Rev-erbα and Bmal1 best discriminated these chronotoxicity classes, among 27 transcriptional 24-hour time series, according to sparse linear discriminant analysis. An 8-hour phase advance was found both for Rev-erbα and Bmal1 mRNA expressions and for irinotecan chronotoxicity in clock-altered Per2(m/m) mice. The application of a maximum-a-posteriori Bayesian inference method identified a linear model based on Rev-erbα and Bmal1 circadian expressions that accurately predicted for optimal irinotecan timing. The assessment of the Rev-erbα and Bmal1 regulatory transcription loop in the molecular clock could critically improve the tolerability of chemotherapy through a mathematical model-based determination of host-specific optimal timing.

The circadian rest-activity rhythm, a potential safety pharmacology endpoint of cancer chemotherapy

The robustness of the circadian timing system (CTS) was correlated to quality of life and predicted for improved survival in cancer patients. However, chemotherapy disrupted the CTS according to dose and circadian timing in mice. A continuous and repeated measures longitudinal design was implemented here to characterize CTS dynamics in patients receiving a fixed circadian-based chemotherapy protocol. The rest-activity rhythm of 49 patients with advanced cancer was monitored using a wrist actigraph for 13 days split into four consecutive spans of 3-4 days each, i.e., before, during, right after and late after a fixed chronotherapy course. The relative amount of activity in bed vs. out of bed (I<O, main endpoint), the autocorrelation coefficient r24, the relative 24-hr amplitude (Amp), interdaily stability (IS) and intradaily variability (IV) were compared according to study span. Circadian disruption (I<O ≤ 97.5%) resulted from the administration of the fixed chronotherapy protocols, with all five rest-activity rhythm parameters being worsened in the whole group of patients (p < 0.05). Mean parameter values subsequently recovered to near baseline values. The occurrence of circadian disruption on chemotherapy was associated with a higher risk of clinically relevant fatigue (p = 0.028) or body weight loss (p = 0.05). Four CTS dynamic patterns characterized treatment response including no change (9.5% of the patients); improvement (14.3%); alteration and complete recovery (31%) or sustained deterioration (45%), possibly due to inadequate chronotherapy dosing and/or timing. Improved clinical tolerability could result from the minimization of circadian disruption through the personalization of chronotherapy delivery.

Inference on periodicity of circadian time series

Estimation of the period length of time-course data from cyclical biological processes, such as those driven by the circadian pacemaker, is crucial for inferring the properties of the biological clock found in many living organisms. We propose a methodology for period estimation based on spectrum resampling (SR) techniques. Simulation studies show that SR is superior and more robust to non-sinusoidal and noisy cycles than a currently used routine based on Fourier approximations. In addition, a simple fit to the oscillations using linear least squares is available, together with a non-parametric test for detecting changes in period length which allows for period estimates with different variances, as frequently encountered in practice. The proposed methods are motivated by and applied to various data examples from chronobiology.

Fatigue and weight loss predict survival on circadian chemotherapy for metastatic colorectal cancer

BACKGROUND

Chemotherapy-induced neutropenia has been associated with prolonged survival selectively in patients on a conventional schedule (combined 5-fluorouracil, leucovorin, and oxaliplatin [FOLFOX2]) but not on a chronomodulated schedule of the same drugs administered at specific circadian times (chronoFLO4). The authors hypothesized that the early occurrence of chemotherapy-induced symptoms correlated with circadian disruption would selectively hinder the efficacy of chronotherapy.

METHODS

Fatigue and weight loss (FWL) were considered to be associated with circadian disruption based on previous data. Patients with metastatic colorectal cancer (n = 543) from an international phase 3 trial comparing FOLFOX2 with chronoFLO4 were categorized into 4 subgroups according to the occurrence of FWL or other clinically relevant toxicities during the initial 2 courses of chemotherapy. Multivariate Cox models were used to assess the role of toxicity on the time to progression (TTP) and overall survival (OS).

RESULTS

The proportions of patients in the 4 subgroups were comparable in both treatment arms (P = .77). No toxicity was associated with TTP or OS on FOLFOX2. The median OS on FOLFOX2 ranged from 16.4 (95% confidence limits [CL], 7.2-25.6 months) to 19.8 months (95% CL, 17.7-22.0 months) according to toxicity subgroup (P = .45). Conversely, FWL, but no other toxicity, independently predicted for significantly shorter TTP (P < .0001) and OS (P = .001) on chronoFLO4. The median OS on chronoFLO4 was 13.8 months (95% CL, 10.4-17.2 months) or 21.1 months (95% CL, 19.0-23.1 months) according to presence or absence of chemotherapy-induced FWL, respectively.

CONCLUSIONS

Early onset chemotherapy-induced FWL was an independent predictor of poor TTP and OS only on chronotherapy. Dynamic monitoring to detect early chemotherapy-induced circadian disruption could allow the optimization of rapid chronotherapy and concomitant improvements in safety and efficacy.

Sex moderates circadian chemotherapy effects on survival of patients with metastatic colorectal cancer: a meta-analysis

BACKGROUND

Molecular circadian clocks can modify cancer chemotherapy effects, with a possible moderation according to sex differences. We investigated whether sex determine the optimal delivery schedule of chemotherapy for metastatic colorectal cancer.

PATIENTS AND METHODS

A meta-analysis was performed using individual data from three international Phase III trials comparing 5-fluorouracil, leucovorin and oxaliplatin administered in chronomodulated (chronoFLO) or conventional (CONV) infusions. The data from 345 females and 497 males were updated at 9 years. The main end point was survival.

RESULTS

Overall survival was improved in males on chronoFLO when compared with CONV (P = 0.009), with respective median values of 20.8 (95% CL, 18.7 to 22.9) and 17.5 months (16.1 to 18.8). Conversely, median survival was 16.6 months (13.9 to 19.3) on chronoFLO and 18.4 months (16.6 to 20.2) on CONV in females (P = 0.012). The sex versus schedule interaction was a strong predictive factor of optimal treatment schedule, with a hazard ratio of 1.59 (1.30 to 1.75) for overall survival (P = 0.002) in multivariate analysis.

CONCLUSIONS

Males lived significantly longer on chronomodulated chemotherapy rather than on conventional chemotherapy. The current chronoFLO schedule deserves prospective assessment as a safe and more effective first-line treatment option than conventional delivery for male patients.

Circadian clocks and drug delivery systems: impact and opportunities in chronotherapeutics

Chronotherapeutics aims at the adjustment of treatments to ∼ 24 h rhythms, which result from the moderation of most biological functions by the circadian timing system (CTS). The integration of CTS-related knowledge in drug delivery concepts challenges most current views, where steady-state constant drug levels are synonymous to enhanced tolerability and efficacy. In contrast, robust molecular clocks rhythmically control Phase I, II and III drug metabolism, as well as pharmacodynamics. Thus, circadian timing of medications predictably modifies drug tolerability and/or efficacy up to several-fold in rodents, as well as in patients. Optimal dosing times indeed complement the recommendations for optimal doses of glucocorticoids, NSAIDs, bronchodilators and so on. Clinically-driven in vitro and in silico circadian data now provide mechanistic insights for the effective translation of chronotherapeutic delivery, especially for cancer therapies. Programmable-in-time electronic or polymeric drug delivery systems are being used for improving health in patients with cancer or rheumatoid diseases, respectively. Current research aims at the optimization of circadian amplitude and phase of drug delivery according to CTS biomarkers. Intelligent drug delivery systems could then integrate the critical rhythmic information stemming from the individual patient and achieve a critical leap forward in the safe administration of potentially toxic therapeutic agents.