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

A Potential Effect of Circadian Rhythm in the Delivery/Therapeutic Performance of Paclitaxel-Dendrimer Nanosystems

The circadian clock controls behavior and physiology. Presently, there is clear evidence of a connection between this timing system and cancer development/progression. Moreover, circadian rhythm consideration in the therapeutic action of anticancer drugs can enhance the effectiveness of cancer therapy. Nanosized drug delivery systems (DDS) have been demonstrated to be suitable engineered platforms for drug targeted/sustained release. The investigation of the chronobiology-nanotechnology relationship, i.e., timing DDS performance according to a patient's circadian rhythm, may greatly improve cancer clinical outcomes. In the present work, we synthesized nanosystems based on an octa-arginine (R8)-modified poly(amidoamine) dendrimer conjugated with the anticancer drug paclitaxel (PTX), G4-PTX-R8, and its physicochemical properties were revealed to be appropriate for in vitro delivery. The influence of the circadian rhythm on its cellular internalization efficiency and potential therapeutic effect on human cervical cancer cells (HeLa) was studied. Cell-internalized PTX and caspase activity, as a measure of induced apoptosis, were monitored for six time points. Higher levels of PTX and caspase-3/9 were detected at T8, suggesting that the internalization of G4-PTX-R8 into HeLa cells and apoptosis are time-specific/-regulated phenomena. For a deeper understanding, the clock protein Bmal1-the main regulator of rhythmic activity, was silenced by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology. Bmal1 silencing was revealed to have an impact on both PTX release and caspase activity, evidencing a potential role for circadian rhythm on drug delivery/therapeutic effect mediated by G4-PTX-R8.

Morphofunctional State and Circadian Rhythms of the Liver of Female Rats under the Influence of Chronic Alcohol Intoxication and Constant Lighting

A separate and combined effect of constant illumination and chronic alcohol intoxication (CAI) on diurnal dynamics of micromorphometric parameters of hepatocytes in female Wistar rats and p53, Ki-67, PER2, BMAL1, and ADH5 expression in these cells were studied. The increase in apoptotic activity and proliferation in all animals under the action of chronodestructors is shown. All experimental animals showed a decrease in BMAL1 expression and increase in PER2 expression; ADH5 is overexpressed under the influence of ethanol. Circadian rhythms (CRs) of BMAL1, PER2, p53, and Ki-67 expression persist in all groups, except combined action of chronodestructors, and ADH5 CRs persist in all groups—thus, these rhythms in females are quite stable. CRs of the hepatocyte nuclei area are preserved in all the studied groups, although they undergo a significant shift. At the same time, the CRs of the hepatocyte area are destroyed under the action of light, both independently and in combination with CAI, and the CR of the nuclear-cytoplasmic ratio (NCR) is destroyed by exposure to CAI. It can be assumed that CRs of the hepatocyte area are significantly affected by dark deprivation and NCR rhythm is sensitive to ethanol consumption, while the stability of studied genes’ expression rhythms at separate influences of studied chronodestructors is maintained by yet unknown adaptation mechanisms. It is necessary to note that, according to our previous studies of male rats, rat females show significantly greater stability of the studied CRs.

[Chronopharmacology : The right timing can be crucial]

BACKGROUND

Chronopharmacology takes into account, among other things, the circadian rhythm, a recurring, daily rhythm of biological functions that is significantly influenced by the day-night rhythm. Daily rhythm, diseases, and therapies influence each other: the circadian rhythm, among other factors, could influence the effect of pharmacological and nonpharmacological therapies, especially in urological oncology.

AIM

This article focuses on the question of the optimal time for therapeutic interventions and considers relevant basics of chronobiological principles depending on possible biomarkers that could be targets of a future therapeutic approach.

RESULTS

With chronomodulated chemotherapy, cancer therapies are not only more tolerable, but also more effective. Effects and side effects of an active substance can change according to the circadian rhythm. Due to the introduction of particularly targeted, oral tumor therapies, a daily application would be organizationally possible, but further clinical studies are necessary for this. The internal clock could play an unexpected role, especially in hormone-dependent prostate cancer: the amount of the circadian factor Cry1 not only seems to increase in the advanced stage, but is also closely associated with a poorer prognosis. Epidemiological studies also show a connection between hormone-dependent tumors and the disruption of the rhythmic release of melatonin. Melatonin appears to be able to improve therapy as an adjunct to cancer therapy in some urological tumor entities.

Paclitaxel Promotes Oxidative Stress-Mediated Human Laryngeal Squamous Tumor Cell Death through the Stimulation of Calcium and Zinc Signaling Pathways: No Synergic Action of Melatonin

The paclitaxel (PAX) and melatonin (MLT)-mediated mitochondria reactive free oxygen radical (miROS) generations via the influx of excessive Ca²⁺ and Zn²⁺ induce tumor cell death and apoptosis. However, a presence of resistance was demonstrated against the PAX treatment in the tumor cells. The stimulation of TRPM2 may increase the anticancer action of PAX after the treatment of MLT. We investigated the stimulating role of PAX with/without MLT on the excessive Ca²⁺ influx and miROS generation-mediated human laryngeal squamous cancer (Hep2) cell death through the stimulation of TRPM2. The Hep2 cells were divided into four groups as control, MLT (1 mM for 2 h), PAX (50 μM for 24 h), and PAX + MLT. In some experiments, we induced additional subgroups such as PAX+ACA and PAX+2APB. The stimulation of TRPM2 induced the increase of TRPM2 current densities, lipid peroxidation, cytosolic ROS, miROS, cytosolic Ca²⁺, and Zn²⁺ values in the Hep2 cells after the treatment of PAX, although their values were decreased by the treatment of MLT and TRPM2 antagonists (ACA and 2APB). In addition, the PAX induced apoptosis and cell death via upregulation of caspases and downregulation of antioxidant glutathione peroxidase and glutathione in the cells. The treatment of PAX increased protein band expression values of TRPM2, PARP-1, and caspase 3 and 9 in the Hep2. The increased expression, apoptotic, and cell death values were not affected by the treatment of MLT. In conclusion, PAX induced the increase of Hep2 cell death via upregulations of TRPM2 and Zn²⁺, although its downregulation via the treatment of MLT did not change the antitumor action of PAX.

Systematic Evaluation Meta-Analysis of the Efficacy of Recombinant Human Endostatin Combined with Gemcitabine and Cisplatin in Non-Small-Cell Lung Cancer

Objective. To evaluate the efficacy of recombinant human endostatin combined with gemcitabine and cisplatin in the treatment of non-small-cell lung cancer (NSCLC). Methods. The databases of Cochrane Library, Embase, ClinicalTrials, PubMed, HowNet, Wanfang, and VIP were searched to collect randomized controlled trials (RCTs) of recombinant human endostatin combined with gemcitabine and cisplatin (experimental group) and gemcitabine combined with cisplatin (control group) for comparative study. The quality of literature was evaluated by bias risk assessment tools and related scales, and then meta-analysis was performed. Results. A total of 27 RCTs (1646 patients) were included. The results of meta-analysis showed that the effective rate ( $P$  < 0.000 01) and benefit rate ( $P$  < 0.000 01) of the experimental group were significantly higher than those of the control group, the incidence of leucopenia ( $P$  = 0.79), thrombocytopenia ( $P$  = 0.39), and gastrointestinal reaction ( $P$  = 0.85) were not statistically significant. Conclusion. The combination of recombinant human endostatin, gemcitabine, and cisplatin can increase the efficacy and safety of NSCLC patients.

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.