Emerging Role of Circular RNAs in Hepatocellular Carcinoma Immunotherapy

Hepatocellular carcinoma (HCC) is a highly fatal malignancy with limited therapeutic options and high recurrence rates. Recently, immunotherapeutic agents such as immune checkpoint inhibitors (ICIs) have emerged as a new paradigm shift in oncology. ICIs, such as programmed cell death protein 1 (PD-1) inhibitors, have provided a new source of hope for patients with advanced HCC. Yet, the eligibility criteria of HCC patients for ICIs are still a missing piece in the puzzle. Circular RNAs (circRNAs) have recently emerged as a new class of non-coding RNAs that play a fundamental role in cancer pathogenesis. Structurally, circRNAs are resistant to exonucleolytic degradation and have a longer half-life than their linear counterparts. Functionally, circRNAs possess the capability to influence various facets of the tumor microenvironment, especially at the HCC tumor-immune synapse. Notably, circRNAs have been observed to control the expression of immune checkpoint molecules within tumor cells, potentially impeding the therapeutic effectiveness of ICIs. Therefore, this renders them potential cancer-immune biomarkers for diagnosis, prognosis, and therapeutic regimen determinants. In this review, the authors shed light on the structure and functional roles of circRNAs and, most importantly, highlight the promising roles of circRNAs in HCC immunomodulation and their potential as promising biomarkers and immunotherapeutic regimen determinants.

Molecular Engines, Therapeutic Targets, and Challenges in Pediatric Brain Tumors: A Special Emphasis on Hydrogen Sulfide and RNA-Based Nano-Delivery

Pediatric primary brain tumors represent a real challenge in the oncology arena. Besides the psychosocial burden, brain tumors are considered one of the most difficult-to-treat malignancies due to their sophisticated cellular and molecular pathophysiology. Notwithstanding the advances in research and the substantial efforts to develop a suitable therapy, a full understanding of the molecular pathways involved in primary brain tumors is still demanded. On the other hand, the physiological nature of the blood-brain barrier (BBB) limits the efficiency of many available treatments, including molecular therapeutic approaches. Hydrogen Sulfide (H2S), as a member of the gasotransmitters family, and its synthesizing machinery have represented promising molecular targets for plentiful cancer types. However, its role in primary brain tumors, generally, and pediatric types, particularly, is barely investigated. In this review, the authors shed the light on the novel role of hydrogen sulfide (H2S) as a prominent player in pediatric brain tumor pathophysiology and its potential as a therapeutic avenue for brain tumors. In addition, the review also focuses on the challenges and opportunities of several molecular targeting approaches and proposes promising brain-delivery strategies for the sake of achieving better therapeutic results for brain tumor patients.

Coaxial laser absorption and optical emission spectroscopy of high-pressure aluminum monoxide

This work advances laser absorption spectroscopy with measurements of aluminum monoxide (AlO) temperature and column density in extreme pressure (P > 60 bar) and temperature (T > 4000 K) environments. Measurements of the AlO A²Π_i-X²Σ⁺ transition are made using a microelectromechanical system, tunable vertical cavity surface emitting laser (MEMS-VCSEL). Simultaneous emission measurements of the AlO B²Σ⁺-X²Σ⁺ transition are made along a line of sight that is coaxial with the laser absorption. Absorption temperature fits agree with emission spectra for a T = 3200 K, P = 9 bar case. In cases with T > 4000 K, P > 60 bar, absorption fits match the ambient temperature while emission fits over-estimate it, owing to high optical depths. These data juxtapose passive and active spectroscopic methods and demonstrate the versatility of AlO laser absorption in high-pressure and high-temperature environments where experimental data remain scarce, and engineering models will benefit from refined measurements.

Cocaine and body temperature: effect of exercise at high ambient temperature

The laboratory rat has been used as an animal model to investigate the effects of cocaine on body temperature and to determine if abuse of the drug is a risk factor in the pathogenesis of exercise-induced heat stroke. Animals were trained to run on a treadmill which was enclosed so that the ambient temperature could be regulated. Exercise at ambient temperatures of 20 and 30 degrees C led to a similar rise in core temperature of approximately 1 degrees C, although the starting core temperature was higher in the rats at 30 degrees C (38.5 +/- 0.10 degrees C compared to 37.9 +/- 0.06 degrees C). Cocaine (20 mg/kg) led to a transient fall in core temperature in the 20 degrees C group; the temperature then rapidly recovered, so that after 60 min exercise there was no significant difference between these and the control animals. At the higher ambient temperature cocaine augmented the rise in core temperature during running, although the animals had regained thermal balance by 30 min and core temperature was maintained at 40.2 +/- 0.13 degrees C until the end of the exercise period. The dopamine D1 receptor antagonist SCH 23390 (0.1, 0.3 or 1.0 mg/kg) led to suppression of spontaneous motor activity so that the rats could be persuaded to exercise for only 30-45 min after treatment. Pretreatment with the antagonist did not affect the rise in core temperature induced by cocaine at 30 degrees C which again stabilized by 30 min at 40.0 +/- 0.12 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Cocaine and body temperature in the rat: effect of exercise

The laboratory rat is being studied as a model to determine if abuse of cocaine constitutes a risk factor in the pathogenesis of stress or exertion induced heatstroke. During running on a treadmill for 60 min under thermoneutral conditions (Ta 22 degrees C) a rise in core temperature of approximately 1 degree C was recorded. Injection of cocaine (10 or 20 mg/kg IP) or its vehicle (0.9% NaCl solution) did not modify the running behavior or the core temperature change. Cocaine (30 mg/kg IP) led to a significant increase in the core temperature (compared to animals treated with saline or the lower doses of cocaine) at 45 and 60 min. The rats recovered rapidly following cessation of exercise. Repeated (3) injections of cocaine (30 mg/kg) at 7-day intervals did not alter the magnitude of the final hyperthermia, i.e., neither tolerance nor potentiation were in evidence.

Cocaine and body temperature in the rat: effects of ambient temperature

The laboratory rat is being developed as a model to determine whether abuse of cocaine constitutes a risk factor in the pathogenesis of stress or exertion-induced heatstroke. Under thermoneutral conditions (Ta 20 degrees C) cocaine (10-40 mg/kg i.p.) caused a dose-dependent fall in core temperature ranging from 0.45 +/- 0.18 to 1.77 +/- 0.26 degrees C. When the ambient temperature (Ta) was increased to 35 degrees C, cocaine (10-40 mg/kg i.p.) led to a dose-dependent hyperthermia (0.3 +/- 0.08 to 1.43 +/- 0.43 degrees C). Repeated injection of cocaine (40 mg/kg at Ta 20 degrees C or 20 mg/kg at Ta 40 degrees C) on days 1, 3, 8, 15, and 23 did not alter the magnitude of the temperature change compared to that following the first injection, i.e., neither tolerance nor potentiation occurred.

Cocaine and body temperature in the rat: effects of exercise and age

The laboratory rat is being used to determine if abuse of cocaine is a risk factor in the pathogenesis of exercise-induced heatstroke. The effect of running on a treadmill on the core temperature (Tc) has been studied in two groups of rats: animals approximately 20 weeks old ('young rats') and animals approximately 52 weeks old ('old rats'). During 60 min running the Tc increased to a steady level, within 15-30 min, which was higher in the old than in the young animals at environmental temperatures (Ta) of 25 and 30 degrees C. A significantly greater rise occurred in both groups of animals at Ta of 30 compared to 25 degrees C. Injection of cocaine (20 mg/kg) was without effect on the rise in Tc in young animals running at a Ta of 25 degrees C but significantly increased the hyperthermia in the old rats. It is suggested that the rise in the thermoregulatory set point induced by muscle exercise is greater with advancing age. Also in older animals, the effect of cocaine on the central nervous system may be enhanced.