Lipid-based nanomedicines (LBNs), including liposomes and mRNA-lipid nanoparticles, have propelled modern drug delivery research; however, they possess significant challenges regarding structural characterization. Cryogenic transmission electron microscopy (cryo-TEM) preserves LBNs in a near-native, hydrated state, enabling high-resolution imaging of both external and internal features. This review discusses the key principles of cryo-TEM, highlights its advantages in characterizing LBNs, and addresses challenges such as precise sample preparation, beam-induced damage, and complexities in analyzing polydisperse specimens. Nevertheless, ongoing advances in instrumentation and workflow automation continue to expand the accessibility and data quality of cryo-TEM. Standardizing protocols and developing reference materials would further strengthen data reproducibility and facilitate regulatory considerations. By offering unparalleled insight into LBN morphology and functionality, cryo-TEM stands at the forefront of nanomedicine development, guiding both fundamental research and the optimization of next-generation therapeutic carriers.

Mitochondria are essential for cellular functions, including ATP production, calcium homeostasis, oxidative stress regulation, and apoptosis. Mitochondrial dysfunction is associated with a variety of diseases, including neurodegenerative disorders, skeletal muscle diseases, and mitochondrial diseases. This review explores the latest mitochondrial-targeted therapeutic approaches across the following key perspectives: (1) technological innovations in mitochondrial transplantation, focusing on tunnel nanotubes and extracellular vesicles; (2) the role of mitochondria in skeletal muscle diseases and therapeutic activation strategies; (3) advances in mitochondrial enhancement techniques within cell therapy, particularly in pediatric applications; and (4) the latest treatment modalities for mitochondrial diseases, such as gene and cell therapies. Taken together, these strategies demonstrate the transformative potential of mitochondrial targeting in cell- and organelle-specific medicine. Additionally, the MITO-Porter system is highlighted as an innovative drug delivery platform contributing to these advances.

Liposomes have a more complex structure than conventional low-molecular-weight pharmaceuticals, so there is concern that quality evaluation items will be diverse and evaluation methods will be complex. Raman spectroscopy has recently attracted attention as a Process Analytical Technology in the pharmaceutical manufacturing, and its application is expected to expand to biopharmaceuticals and other drugs with complex manufacturing in the future. We have demonstrated that the combination of probe-type Raman spectrometer and partial least squares analysis enables real-time quantification of drug inclusion rate and drug release rate from liposomes, and is useful as a new quality assessment method for liposomes. In this study, we evaluated the phase transition of drug-encapsulated liposomes and the accompanying drug release by using Raman spectroscopy. Drug-encapsulated liposomes were prepared by preparing liposomes with different cholesterol (CHOL) ratios. The phase transition and drug release of liposomes were evaluated by using Raman spectroscopy. Raman spectroscopic measurements showed that the peak intensity of the phase transition was large in systems with low CHOL ratios, while it was low in systems with high CHOL ratios. In the drug release test, a decrease in the peak intensity of the drug-derived spectra over time was observed significantly in the low CHOL ratio system compared to the high CHOL ratio system which is supposed to release drug lower due to liquid-ordered phase, suggesting that the drug release property increased in the low CHOL system. Thus, Raman spectroscopy can be used to evaluate the phase transition and the associated drug release properties of liposomes.

Liposomes are small vesicles composed of lipid bilayers, which have been widely studied and are used in drug delivery systems (DDSs). The lipid bilayers, as two-dimensional liquid crystalline structures, show different phase states, and temperature-dependent phase transitions occur as a result of the thermotropic alteration of the physicochemical properties of the lipid bilayers, resulting in drastic changes in the morphology and dynamics of the fluctuations of the lipid bilayers. Analysis of the thermotropic phase behavior of the liposomal lipid bilayer is crucial for the development and application of functional liposomes for DDSs. We constructed a differential scanning fluorimetry (DSF) method that enabled observation and analysis of the thermotropic phase transitions and temperatures of liposomal lipid bilayers using a real-time PCR device and solvatochromic dyes, which have fluorescence characteristics that reflect alterations in the polar environment. This DSF method using Nile Red and a tandem thermal sequence enabled analysis of the phase transition temperatures of three liposomal phosphatidylcholines, and not only the T_m and T_p, but also the T_sub values, except for the T_p value of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, were clearly determined. Other solvatochromic dyes could not be used to determine the T_sub values clearly. The measured phase transition temperatures of three liposomal phosphocholines correlated well with the reported values. Our DSF method has several practical advantages over the typical thermal analytical method, differential scanning calorimetry, including reduced sample volume and analytical time, which may contribute to expanding the opportunities for the physicochemical analysis of liposomal lipid bilayers.

Multiple sclerosis (MS) develops due to an abnormal T-cell immune response to autoantigens and control of T-cell activation is a mainstream approach for its treatment. In the present study, neogenin, a key molecule for T-cell activation, was used as a targeted molecular gene therapy for MS. Lipid nanoparticles (LNPs) loaded with small interfering RNA (siRNA) targeting neogenin (LNPsiNeo) were prepared, and their therapeutic effect on experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein, a model of MS was evaluated. Neogenin gene expression was reduced by LNPsiNeo in mouse EL-4 cells and splenocytes of LNPsiNeo-treated EAE mouse. Additionally, fluorescence-activated cell sorting (FACS) revealed that the number of CD4⁺ T cells in the splenocytes of EAE mouse decreased after intravenous injection of LNPsiNeo. Furthermore, the progression of encephalomyelitis symptoms was significantly suppressed by LNPsiNeo, whereas the lipid nanoparticle with control siRNA failed to show any effect. The present study suggests that neogenin is a target molecule for EAE gene therapy and LNPsiNeo may be suitable for the MS treatment.

Magnetic drug carriers are a valuable tool for site-specific drug delivery, utilizing both passive targeting via the enhanced permeability and retention effect and active targeting through magnetic forces. We previously developed magnetic anionic liposome (Mag-AL)/atelocollagen (ATCOL) complexes and demonstrated their efficient accumulation at the targeted tissue through magnetic attraction and electrostatic interactions. To assess the usefulness of Mag-AL/ATCOL complexes as tumor-targeted drug delivery carriers, we herein prepared paclitaxel (PTX)-loaded Mag-AL/ATCOL complexes and examined their cellular association and cytotoxicity in C26 murine colon adenocarcinoma cells. The biodistribution of the complexes and their antitumor efficacy were also investigated in C26-bearing mice. PTX-Mag-AL/ATCOL complexes exhibited significant binding to C26 cells under an external magnetic field and released PTX in a sustained manner. Consequently, cytotoxic effects against C26 cells were achieved by PTX-Mag-AL/ATCOL complexes with the application of a magnetic field. Moreover, PTX-Mag-AL/ATCOL complexes preferentially distributed in the spleen and liver after their intravenous administration into C26 tumor-bearing mice, while tumor accumulation showed an approximately 2.9-fold augmented by the application of an external magnetic field to the tumor. Due to this magnetic guidance, PTX-Mag-AL/ATCOL complexes significantly inhibited C26 tumor growth. These results indicate that Mag-AL/ATCOL complexes have the potential to improve the therapeutic efficacy of anticancer drugs as magnetic drug carriers.

Amyloid-β peptide (Aβ) is eliminated from the brain across the blood–brain barrier (BBB) by an insulin-sensitive process. To investigate the involvement of insulin-degrading enzyme (IDE) in this process, the present study was implemented to clarify the effect of a novel IDE-specific inhibitor, Ii1, on the elimination of [¹²⁵I]Aβ(1-40) from rat brain via the brain efflux index method. The results showed that such elimination was significantly inhibited by the co-administration of Ii1. The maximum inhibitory effect of Ii1 and IC₅₀ were 69.4% and 9.96 µM, respectively. Insulin alone inhibited the elimination of [¹²⁵I]Aβ(1-40), but the inhibitory effect of co-administering insulin and Ii1 was not significantly different from that of Ii1 alone. Meanwhile, thiorphan, an inhibitor of neprilysin, showed an additive inhibitory effect with Ii1. Aβ(1-13) and Aβ(1-14), which are major fragments produced by the degradation of Aβ(1-40) by IDE, and inhibitors of receptor for advanced glycation end products (RAGE) did not significantly inhibit the [¹²⁵I]Aβ(1-40) elimination. These results suggest that IDE is involved in the insulin-sensitive process of [¹²⁵I]Aβ(1-40) elimination across the BBB, to which neprilysin and RAGE make minor contributions. These findings suggest that impairment of IDE may be involved in the onset of sporadic Alzheimer’s disease.

Pregabalin is a first-line treatment for neuropathic pain, but its oral use is often limited by central nervous system side effects, which may require dose reduction or discontinuation. A transdermal formulation may help minimize this adverse effect. The aim of this study was to improve the skin permeability of pregabalin by assessing the feasibility of in-hospital preparation and evaluating its stability in the early stages of formulation development. A 0.4% pregabalin formulation was prepared using hydrophilic cream, lipophilic cream, and pluronic lecithin organogel (PLO) gel. Ex vivo skin permeation studies were conducted using Franz diffusion cells and excised dorsal skin from hairless male mice (HR-1, 7 weeks old). Samples were collected over time and analyzed by LC-tandem MS. Drug content, pH, and viscosity were assessed under 2 storage conditions (25°C/60% relative humidity [RH] and 40°C/75% RH) to evaluate stability. The hydrophilic cream showed the highest cumulative drug permeation, flux, and permeability coefficient. Penetration enhancers added to the PLO gel did not improve absorption. Drug content remained stable under 25°C/60% RH. An inverse correlation was observed between viscosity and drug permeation, suggesting that lower viscosity facilitated diffusion. pH values remained within the physiological range, indicating low irritation potential. The hydrophilic cream demonstrated superior transdermal delivery characteristics for pregabalin. These findings support its potential as an effective and safe alternative to oral administration for managing neuropathic pain.

Tumor necrosis factor-α inhibitors (TNFis) are associated with a risk of paradoxical psoriasis, but quantitative data remain limited. One proposed mechanism is the induction of interferon (IFN) production following TNFi administration. Etanercept and certolizumab pegol, which contain immunoglobulin fragments in their structures, reportedly induce IFN production in T cells more than monoclonal antibody (mAb) TNFi agents. Based on this, we hypothesized that non-mAb TNFi agents might carry a higher risk of paradoxical psoriasis than mAb agents. This study compared the risk of paradoxical psoriasis between mAb and non-mAb TNFi agents in rheumatoid arthritis (RA) patients. Using a claims database, we identified 1577 subjects in the mAb group and 1517 in the non-mAb group. Patient characteristics, including sex, age, and prior RA treatment, were extracted, and the onset of psoriasis was identified. Multivariable Cox regression analysis showed the hazard ratio (HR) for psoriasis onset in the mAb group versus the non-mAb group was 1.66 (95% confidence interval [CI]: 0.79–3.48). Subgroup analyses revealed that compared to etanercept, the HR for adalimumab was 1.43 (95% CI: 0.49–4.19), and compared to certolizumab pegol, it was 0.67 (95% CI: 0.19–2.39). These findings suggest that our hypothesis was not supported and that the risk of paradoxical psoriasis may vary even among non-mAb agents, as indicated by differences observed between etanercept and certolizumab pegol.

In vitro studies have reported that multiple vitamins may promote bacterial growth and infection. In clinical practice, patients receiving peripheral parenteral nutrition (PPN) may develop catheter-related bloodstream infections (CRBSIs). Since some PPN formulations contain multiple vitamins, they may increase the risk of CRBSIs. Therefore, the present study investigated the relationship between PPN infusions containing vitamins and the incidence of CRBSIs and examined the effects of different antiseptics used before catheter insertion. Patients were divided into the following groups: those receiving the BFLUID injection (1 vitamin), those receiving the PAREPLUS injection (9 vitamins), those disinfected with povidone iodine before the PAREPLUS injection, and those disinfected with chlorhexidine alcohol before the PAREPLUS injection. We analyzed infection rates in each group. The PAREPLUS group showed a significantly higher rate of infections by Staphylococcus species. Furthermore, a longer duration of PPN administration (≥2 weeks) was associated with a higher risk of CRBSI across all detected pathogens. Vitamin-enriched PPN increased approximately 2-fold in CRBSI compared with a thiamine-only formulation, independent of infusion duration. However, the incidence of CRBSI did not significantly differ between the different antiseptic groups. These results suggest that proper infection control and careful management are essential during PPN therapy, especially when multiple vitamin products are used over extended periods.

In Japan, the simple N-substituted substances triethylamine and trimethylamine have been designated possibly hazardous air pollutants also requiring further investigation to protect the aquatic environment. Triethylamine is relevant to human biomonitoring in manufacturing workers because of its possible adverse effects; in contrast, trimethylamine exposure from normal daily dietary consumption is considered nontoxic. Although a role for flavin-containing monooxygenase 3 in the metabolism of triethylamine was recently reported, no simplified physiologically based pharmacokinetic (PBPK) model to estimate human plasma and urinary levels of triethylamine and its N-oxide has currently been developed. In this study, in silico human plasma and urine concentrations of triethylamine were estimated after virtual oral administration using a newly established triethylamine PBPK model. The results were compared with our previously established trimethylamine PBPK model. In silico plasma and urinary concentration curves were generated after single virtual administrations of triethylamine and trimethylamine. After 28 d of daily exposure to reported maximum oral doses of triethylamine and trimethylamine from the public water supply of 0.02 and 0.68 µg/kg body weight/d, respectively, the mean modeled urinary levels for the final day were 3.7 and 1.1 pmol/mL. The proposed occupational standard of 10 mg triethylamine/m³ of air reportedly corresponds to a urinary excretion of approx. 0.4 nmol/mL. The results of the current forward dosimetry analyses, therefore, indicate at least a two-order safety margin (drinking water versus occupational standard) for triethylamine. The present PBPK model for triethylamine and its N-oxide could estimate daily exposures using forward dosimetry and thereby facilitate risk assessment in humans.

This study investigated the protective effects of metformin against combined high glucose (HG)- and UVA-induced cytotoxicity in fetal rat skin keratinocytes (FRSK cells), a model of diabetic photoaging. HG combined with UVA caused a synergistic loss of cell viability accompanied by marked increases in phosphorylation of AMP-activated protein kinase (p-AMPK), reactive oxygen species (ROS) generation, senescence-associated β-galactosidase (SA-β-Gal) activity, and Sirtuin 1 (SIRT1) expression. HG alone induced moderate cytotoxicity and senescence, whereas UVA alone under normal glucose conditions (NG + UVA) produced negligible ROS and minimal viability loss. Metformin improved cell viability under dual stress conditions in a dose-dependent manner, with maximal protection observed at 8 mM. In UVA-free cultures, metformin increased p-AMPK in both NG and HG, peaking at 8 mM. Under HG + UVA, p-AMPK was higher than in NG + UVA and HG alone, with no additional increase following metformin treatment. ROS accumulation occurred only under HG + UVA and was strongly suppressed by metformin, nearly to baseline at 8 mM. The HG + UVA-induced increases in SA-β-Gal activity and SIRT1 expression were reduced in parallel with ROS suppression. These findings suggest that metformin’s cytoprotective effect in this model is primarily mediated by attenuation of ROS rather than by further AMPK activation, indicating an AMPK-independent antioxidant mechanism.

The aim of this study was to investigate whether ginsenoside Rb1 attenuates cockroach extract (CRE)-induced asthma by interfering with mitochondrial dysfunction. After induction with CRE, mice were administered different doses of Rb1. Hematoxylin–eosin (H&E) staining, enzyme-linked immunosorbent assay (ELISA), and flow cytometry analysis revealed that inflammatory cell infiltration, total immunoglobulin E (IgE) and CRE-specific IgE in serum, and inflammatory cytokines in bronchoalveolar lavage fluid were effectively inhibited by Rb1. Through Western blot, TUNEL, and immunofluorescence colocalization assays, we observed Rb1 also inhibited endogenous reactive oxygen species (ROS), tightly associated with increased superoxide dismutase, catalase levels, and decreased malondialdehyde levels. Subsequently, the silent information regulator sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) pathway was activated, whereas the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway was inhibited. Additionally, Rb1 could rescue mitochondrial dysfunction by promoting the mitochondrial fusion protein mitofusion 1 (MFN1) and inhibiting dynamin-related protein 1 (DRP1) expression and apoptosis in the lungs. In BEAS-2B cells, Rb1 plays a role similar to that of a SIRT1 agonist (SRT1720), including enhancing mitochondrial membrane potential and decreasing mitochondrial ROS and DRP1 translocation to mitochondria. Our findings suggest that Rb1 maintains mitochondrial integrity by activating SIRT1/PGC-1α and inhibiting PI3K/AKT, thereby ameliorating asthmatic airway inflammation.

“Antibody engineering” is a promising strategy for generating high-affinity antibodies required for developing sensitive immunoassays. Therein, the variable domains (V_H and V_L) of the parental antibody are genetically randomized and combined to produce diverse single-chain Fv fragment (scFv) molecules. Subsequently, high-affinity scFv mutants are selectively isolated. In the randomization process, mutations have conventionally been targeted to the complementarity-determining regions (CDRs) in the variable domains, which often interact directly with antigens. However, we previously discovered that, pinpoint insertion of only a single amino acid (leucine, asparagine, aspartic acid, proline, glutamine, arginine, or histidine) between positions 6 and 7 in the framework region 1 (FR1) of the V_H, which is unlikely to interact with antigens, enhanced the affinity of an anti-cortisol scFv (original K_a, 3.6 × 10⁸ M⁻¹) up to 17–61-fold. These findings prompted us to conduct a comprehensive study of this affinity-enhancement phenomenon involving the remaining amino acids. Thus, we generated the necessary 13 scFv mutants and compared their K_a values. Remarkably, all mutants showed enhanced affinities, similar to those of the previous 7 mutants. Among the 20 mutants, the leucine-inserted scFv showed the largest K_a (2.2 × 10¹⁰ M⁻¹) and consequently enabled a 75-fold more sensitive enzyme-linked immunosorbent assay (midpoint, 9.86 pg/assay) compared to the assay using the parental scFv (midpoint, 744 pg/assay). In silico modeling suggested that, regardless of the amino acid inserted, elongated FR1 can alter the conformation of the CDR3 in V_H to facilitate a favorable interaction with cortisol.

It is known that the daily feeding cycle affects the dosing time-dependent changes in the pharmacodynamics and pharmacokinetics of many drugs. Our previous study demonstrated that administration of empagliflozin (EMPA), sodium-glucose cotransporter 2 (SGLT2) inhibitor, at the beginning of daily feeding cycle (active phase) effectively prevents the development of neuropathic pain in streptozotocin (STZ)-induced diabetic mice. Although the blood glucose levels are closely related to feeding, the relationship between the daily feeding cycle and the optimal dosing time of EMPA remains unclear. In this study, we used STZ-induced diabetic mice and implemented a daily time-restricted feeding (TRF) regimen to investigate whether the dosing time-dependent preventive effect of EMPA on the diabetic neuropathy is modulated by TRF. Animals were housed under a 12-h light/dark cycle, and were assigned to either light-phase TRF (feeding during the light phase) or dark-phase TRF (feeding during the dark phase). The hypoglycemic effect of EMPA was enhanced when the drug was administrated at the beginning of both TRF conditions. A similar influence of the daily feeding cycle on the dosing time-dependent hypoglycemic effect of EMPA was also observed in its preventive effect on the development of diabetic neuropathic pain. Further analysis revealed that dosing time-dependent variations in both the hypoglycemic effect of EMPA and its preventive effect on diabetes-induced pain hypersensitivity were attributable to corresponding changes in urinary glucose excretion. Our results support the notion that the administration of EMPA at the onset of daily feeding cycle effectively suppresses the development of diabetic peripheral neuropathy.

To study the toxicity of fentanyl analogs that damage the liver and kidneys in rats, these analogs were evaluated by examining two types of μ-opioid receptor (MOR) signaling responses using HEK293 cells. The results indicated that, in the MOR-mini-Gi recruitment assay, the 50% effective concentration (EC₅₀) ranked as iBF < DAMGO ≈ 4F-iBF < 4Cl-iBF, and the maximum response (E_max) ranked as iBF ≈ DAMGO > 4F-iBF > 4Cl-iBF. In the MOR-β-arrestin 2 recruitment assay, the EC₅₀ ranking was DAMGO < iBF < 4F-iBF < 4Cl-iBF, and the E_max ranking was DAMGO > iBF > 4F-iBF. In addition, each of the desphenethylated metabolites, likely the major metabolites of these analogs, showed no MOR signaling responses.

Radiation therapy exerts its therapeutic effect by killing cells via the induction of DNA double-strand breaks (DSBs) in malignant tumors, but cancer cells can repair damaged DNA, leading to radiation resistance (radioresistance). Therefore, a radiosensitizing effect can be expected by suppressing mechanism(s) involved in DNA repair after irradiation. Here, we show that the P2Y12 receptor is involved in the radioresistance of mouse B16 melanoma cells, and that P2Y12 antagonist treatment decreases the radioresistance both in vitro and in vivo by inhibiting DNA repair after γ-irradiation. P2Y12 receptor antagonists Clopidogrel and PSB0739 increased cellular sites of unrepaired DNA by suppressing the DNA damage response (DDR) after γ-irradiation and enhanced radiation-induced proliferative death in B16 melanoma cells. On the other hand, ADP (a P2Y12 receptor agonist) enhanced DDR after γ-irradiation and increased radioresistance. Knockdown of the P2Y12 receptor resulted in an increase of unrepaired DNA damage and enhanced proliferative death after γ-irradiation. Suppression of the P2Y12 receptor also contributed to the enhancement of the cancer-killing effect of γ-irradiation, even in fractionated irradiation samples in which the cancer-killing effect decreased due to sublethal damage recovery. Finally, PSB0739 significantly enhanced the antitumor effect of γ-irradiation in vivo. Our results suggest that P2Y12 receptor antagonists are promising candidates as radiosensitizers to improve radiation therapy.

The hypovascular nature of pancreatic tumors creates a nutrient-scarce, hypoxic microenvironment, yet pancreatic cancer cells adapt by altering their metabolism to thrive under austere conditions—a phenomenon known as “austerity.” Targeting this adaptation offers a promising strategy for next-generation therapeutics that selectively impair pancreatic cancer cell viability in nutrient-deprived states without toxicity under nutrient-rich conditions. Here, we evaluated the anti-pancreatic cancer properties of grandifloridin D, a synthetic derivative of (+)-grandifloracin. In vitro antiausterity assays demonstrated that grandifloridin D potently and preferentially reduced the viability of MIA PaCa-2 pancreatic cancer cells under nutrient deprivation at a PC₅₀ concentration of 0.14 μM. Live-cell imaging and ethidium bromide/acridine orange (EB/AO) dual staining confirmed that grandifloridin D induces cell death by disrupting membrane integrity. Under nutrient-rich conditions, grandifloridin D exhibited antimetastatic activity, significantly inhibiting MIA PaCa-2 cell migration in real-time assays and suppressing colony formation and spheroid formation. Western blot analysis revealed that grandifloridin D is a potent inhibitor of the protein kinase B (Akt) and mammalian target of rapamycin (mTOR) signaling pathway while also suppressing the autophagy-related proteins microtubule-associated protein 1 light chain 3 (LC3). These results suggest that grandifloridin D is a promising antiausterity agent for pancreatic cancer drug development.

Metabolic enzymes are occasionally downregulated in in vitro induction studies. Recently, HepaRG cells have been used for CYP induction assays instead of human hepatocytes in the early drug discovery stage; however, there is limited information on CYP downregulation by drug stimulation. In this study, we evaluated the effect of hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors, which downregulate CYP in human hepatocytes, on CYP gene expression in HepaRG cells. Microarray analysis to determine the expression levels of pharmacokinetics-related enzymes and RT-PCR to determine the expression levels of CYP3A4, CYP2B6, CYP1A2, and their nuclear receptor mRNA were conducted in HepaRG cells treated with HIF-PH inhibitors. Treatment of HepaRG cells with HIF-PH inhibitors decreased the expression of several pharmacokinetics-related metabolic enzymes, whereas Erythropoietin (EPO) and Pyruvate Dehydrogenase Kinase1 (PDK1) genes were induced. The expression of CYP3A4 and CYP2B6 in HepaRG cells showed concentration- and time-dependent downregulation following treatment with the HIF-PH inhibitor. The downregulation of these enzymes was correlated with the decrease of PXR/RXRα and CAR/RXRα, respectively. CYP1A2 decreased transiently, but recovered with continued HIF-PH inhibitor treatment. CYP3A4 and CYP2B6 were downregulated by HIF-PH inhibitors in HepaRG cells and human hepatocytes. In contrast, CYP1A2 in HepaRG cells responded differently to HIF-PH inhibitors than in human hepatocytes. Since CYP downregulation is commonly observed with HIF-PH inhibitors, along with the induction of EPO and PDK1 genes, stabilizing HIF may be one of the factors involved in CYP downregulation.

Opioid analgesics are indispensable therapeutic agents for patients experiencing cancer pain. Recently, immune checkpoint inhibitors (ICIs) have made substantial progress in cancer treatment, and the range of cancer types for which they are applicable has expanded. Consequently, the combined use of ICIs with other drugs has also increased. However, it has been pointed out that ICIs may interfere with opioid nociception and weaken the analgesic effects of opioids. Therefore, in this study, we investigated the drug–drug interactions between opioid analgesics and ICIs in patients with cancer, especially their influence on analgesic effects. A multicenter collaborative study was conducted to investigate changes in pain intensity in patients with cancer pain who were prescribed opioid analgesics and ICIs. As a result, when opioids were administered to patients receiving ICIs, the median pain intensity, measured using the Numerical Rating Scale (NRS), significantly decreased from 4.5 at baseline to 3.0 on Day 1 and 2.5 on Day 7, demonstrating favorable analgesic effects. Similarly, when ICIs were administered to patients receiving opioids, the median pain intensity (NRS) significantly decreased from 3.0 at baseline to 2.0 on Day 1 and 2.75 on Day 7. These results suggest that opioids provided effective analgesia when administered alongside ICIs.