Impaired Capillary Recruitment Capacity in Obesity: A Subgroup Analysis of Prospective Observational Study on Anesthesia Effects.

BACKGROUND This subgroup analysis of prospective observational research, involving 71 participants, compared the effects of anesthesia on microvascular reactivity in obese vs lean individuals using near-infrared spectroscopy and vascular occlusion tests. The correlation between the body mass index (BMI) and microvascular reactivity under general anesthesia was also investigated. MATERIAL AND METHODS This study enrolled adult patients classified as American Society of Anesthesiologists physical status I or II, undergoing elective surgery under general anesthesia. The microcirculatory variables measured before (Tpre) and 30 min following the induction of anesthesia (Tpost) were as follows: baseline tissue oxygen saturation (StO2), occlusion slope (∇occl), and recovery slope (∇recov). The patients were grouped according to their BMI (lean [BMI <25 kg/m²] vs obese [BMI ≥25 kg/m²]). Data are presented as medians and interquartile ranges. RESULTS There were 43 patients in the lean group and 28 in the obese group. At Tpre, baseline StO2, ∇occl, and ∇recov were not different between the 2 groups (P=0.860, 0.659, and 0.518, respectively). At Tpost, the baseline StO2 and ∇occl were not different between the 2 groups (P=0.343 and 0.791); however, the ∇recov was lower in the obese group than in the lean group (3.245 [2.737, 3.977] vs 4.131 [3.491, 4.843], P=0.003). At Tpost, BMI showed a moderate correlation with ∇recov (correlation coefficient: -0.319, P=0.007). CONCLUSIONS In obese patients, capillary recruitment capacity during general anesthesia is compromised compared to lean patients.

Resolution of Nonmass Enhancement Extension to the Nipple at Breast MRI after Neoadjuvant Chemotherapy: Pathologic Response and Feasibility for Nipple-sparing Mastectomy.

Background Nipple-sparing mastectomy (NSM) is usually contraindicated in patients with nonmass enhancement (NME) extension to the nipple at breast MRI. However, little is known about the feasibility of NSM when NME extension to the nipple resolves after neoadjuvant chemotherapy (NAC). Purpose To evaluate whether NSM is an appropriate surgical procedure for patients in whom NME extension to the nipple resolves after NAC. Materials and Methods This retrospective study included 383 women with NME at baseline MRI who underwent NAC followed by mastectomy between January 2007 and March 2022 at a single institution. NME extension to the nipple was assessed using breast MRI before NAC (hereafter, pre-NAC) and after NAC (hereafter, post-NAC). In 326 women who underwent mastectomy with removal of the nipple-areolar complex, the rate of pathologic analysis-confirmed tumor invasion of the nipple compared with NME extension to the nipple at post-NAC breast MRI was evaluated. Tumor involvement of the nipple was also assessed in those with complete pathologic response at posttreatment MRI. Furthermore, the outcomes in 57 women undergoing NSM were investigated, particularly in patients with NME extension to the nipple at initial diagnosis. Results Of the 326 women who underwent mastectomy with removal of the nipple-areolar complex (mean age, 49 years ± 9.4 [SD]), 217 patients (67%) showed NME extension to the nipple on pre-NAC MRI scans. Among the 153 women (70%) in whom the NME extension to the nipple resolved after NAC, the rate of pathologic analysis-confirmed tumor invasion of the nipple was 2.6% (four of 153 women; 95% CI: 0, 6.5). No pathologic analysis-confirmed tumor invasion of the nipple was detected in 31 women with complete response at MRI. Of the 57 women who underwent NSM, 12 (21%) with resolution of NME extension to the nipple after NAC had no relapse during the median follow-up of 31 months (range, 11-80 months). Conclusion Pathologic analysis-confirmed tumor invasion of the nipple was rare in women with resolution of nonmass enhancement extension to the nipple after neoadjuvant chemotherapy (NAC). Therefore, nipple-sparing mastectomy could be feasible in this population, especially in those with complete MRI response to NAC. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Lee in this issue.

Toward reducing the immunogenic potential of wheat flour: identification and characterization of wheat lines missing omega-5 gliadins encoded by the 1D chromosome.

KEY MESSAGE: Eleven wheat lines that are missing genes for the 1D-encoded omega-5 gliadins will facilitate breeding efforts to reduce the immunogenic potential of wheat flour for patients susceptible to wheat allergy. Efforts to reduce the levels of allergens in wheat flour that cause wheat-dependent exercise-induced anaphylaxis are complicated by the presence of genes encoding omega-5 gliadins on both chromosomes 1B and 1D of hexaploid wheat. In this study, we screened 665 wheat germplasm samples using gene specific DNA markers for omega-5 gliadins encoded by the genes on 1D chromosome that were obtained from the reference wheat Chinese Spring. Eleven wheat lines missing the PCR product corresponding to 1D omega-5 gliadin gene sequences were identified. Two of the lines contained the 1BL·1RS translocation. Relative quantification of gene copy numbers by qPCR revealed that copy numbers of 1D omega-5 gliadins in the other nine lines were comparable to those in 1D null lines of Chinese Spring, while copy numbers of 1B omega-5 gliadins were like those of Chinese Spring. 2-D immunoblot analysis of total flour proteins from the selected lines using a specific monoclonal antibody against the N-terminal sequence of omega-5 gliadin showed no reactivity in regions of the blots containing previously identified 1D omega-5 gliadins. Interestingly, RP-UPLC analysis of the gliadin fractions of the selected lines indicated that the expression of omega-1,2 gliadins was also significantly reduced in seven of the lines, implying that 1D omega-5 gliadin and 1D omega-1,2 gliadin genes are tightly linked on the Gli-D1 loci of chromosome 1D. Wheat lines missing the omega-5 gliadins encoded by the genes on 1D chromosome should be useful in future breeding efforts to reduce the immunogenic potential of wheat flour.

Ubiquitination Links DNA Damage and Repair Signaling to Cancer Metabolism.

Changes in the DNA damage response (DDR) and cellular metabolism are two important factors that allow cancer cells to proliferate. DDR is a set of events in which DNA damage is recognized, DNA repair factors are recruited to the site of damage, the lesion is repaired, and cellular responses associated with the damage are processed. In cancer, DDR is commonly dysregulated, and the enzymes associated with DDR are prone to changes in ubiquitination. Additionally, cellular metabolism, especially glycolysis, is upregulated in cancer cells, and enzymes in this metabolic pathway are modulated by ubiquitination. The ubiquitin-proteasome system (UPS), particularly E3 ligases, act as a bridge between cellular metabolism and DDR since they regulate the enzymes associated with the two processes. Hence, the E3 ligases with high substrate specificity are considered potential therapeutic targets for treating cancer. A number of small molecule inhibitors designed to target different components of the UPS have been developed, and several have been tested in clinical trials for human use. In this review, we discuss the role of ubiquitination on overall cellular metabolism and DDR and confirm the link between them through the E3 ligases NEDD4, APC/CCDH1, FBXW7, and Pellino1. In addition, we present an overview of the clinically important small molecule inhibitors and implications for their practical use.

Clinical usefulness of noninvasive fibrosis indices for predicting hepatocellular carcinoma in treatment-naïve patients with chronic hepatitis B following entecavir therapy.

AIMS: This study aimed to evaluate the clinical usefulness of the aminotransferase to platelet ratio index (APRI), fibrosis-4 (FIB-4), and modified FIB-4 (mFIB-4) indices in predicting hepatocellular carcinoma (HCC) in patients receiving entecavir (ETV) treatment. METHODS: Among 1955 patients treated with ETV, a total of 857 treatment-naive chronic hepatitis B patients (424 with liver cirrhosis [LC], 433 without cirrhosis) treated with ETV for more than 1 year were analyzed. RESULTS: Of the 857 patients, 85 (9.9%) patients (77 in the LC group and 8 in the non-LC group) developed HCC during the follow-up period. The median observation period was 6.9 years. Multivariate regression analysis of HCC incidence revealed that the initial mFIB-4 index (hazard ratio [HR] 1.058; 95% confidence interval [CI], 1.007-1.112; p = 0.027) and improvement in the FIB-4 index after 1 year of ETV treatment (HR 0.531; 95% CI, 0.339-0.831; p = 0.006) were independent prognostic factors in the entire cohort. In the LC group, the improvement of the FIB-4 index following ETV treatment (HR 0.491; 95% CI, 0.280-0.861; p = 0.013) was negatively correlated with incidence of HCC. However, the area under the receiver operating characteristic curve of specific cut-off values of the FIB-4 index at baseline and 1 year after ETV treatment were 0.572 (95% CI, 0.504-0.640) and 0.615 (95% CI, 0.546-0.684), respectively. In the non-LC group, none of the invasive fibrosis indices could predict HCC incidence. CONCLUSIONS: The specific cut-off value of the FIB-4 index was not suitable for predicting HCC. However, the improvement in the FIB-4 index after 1 year of ETV therapy could be a predictor of HCC development in cirrhotic patients.

Comparable Incidence of Hepatocellular Carcinoma in Chronic Hepatitis B Patients Treated with Entecavir or Tenofovir.

BACKGROUND/AIMS: Adherence to medication and maintained virologic response (MVR) are related to the risk of adverse clinical outcomes. This study aimed to compare the efficacy of entecavir (ETV) and tenofovir disoproxil fumarate (TDF) in relation to the adverse clinical outcomes among chronic hepatitis B (CHB) patients stratified according to adherence to medication and MVR. METHODS: A total of 1794 treatment-naive CHB patients treated with ETV (n = 894) or TDF (n = 900) for > 1 year were identified. RESULTS: Adherence rates were significantly higher in the TDF than in the ETV (93.4% vs. 89.1%, respectively; P < 0.001). The MVR of ETV and TDF were 64.5% and 71.7%, respectively (P = 0.001). The MVR of ETV and TDF in the good adherence group were 72.1% and 76.4%, respectively (P = 0.083); in the poor adherence group, the MVR of ETV and TDF were 63.0% and 54.0%, respectively (P = 0.384) Multivariate analysis showed that the risk of HCC and death or transplantation was similar between groups (HR 0.826, 95% CI 0.522-1.306; P = 0.413 and HR 0.636, 95% CI 0.258-1.569; P = 0.325, respectively) after adjusting for adherence to medication and MVR. In the 589 propensity-matched pairs of patients, risk of HCC and death or transplantation was similar between treatment groups after stratification according to adherence rates and MVR. CONCLUSIONS: After adjustment for adherence and MVR, ETV, and TDF did not differ in terms of the risk of HCC and death or transplantation in all patients and propensity score-matched cohorts.

Triglyceride glucose index is an independent predictor for the progression of coronary artery calcification in the absence of heavy coronary artery calcification at baseline.

BACKGROUND: Data on the relationship between the triglyceride glucose (TyG) index and coronary artery calcification (CAC) progression is limited. This longitudinal study evaluated the association of TyG index with CAC progression in asymptomatic adults. METHODS: We enrolled 12,326 asymptomatic Korean adults who had at least two CAC evaluations. The TyG index was determined using ln (fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2). CAC progression was defined as a difference ≥ 2.5 between the square roots (√) of the baseline and follow-up coronary artery calcium score (CACS) (Δ√transformed CACS). Annualized Δ√transformed CACS was defined as Δ√transformed CACS divided by the inter-scan period. RESULTS: During a mean 3.3 years, the overall incidence of CAC progression was 30.6%. The incidence of CAC progression (group I [lowest]: 22.7% versus [vs.] group II: 31.7% vs. group III [highest]: 37.5%, P < 0.001) and annualized Δ√transformed CACS (group I: 0.46 ± 1.44 vs. group II: 0.71 ± 2.02 vs. group III: 0.87 ± 1.75, P < 0.001) were markedly elevated with increasing TyG index tertiles. Multivariate linear regression analysis showed that TyG index was associated with annualized Δ√transformed CACS (ß = 0.066, P = 0.036). In multivariate logistic regression analysis, the TyG index was significantly associated with CAC progression in baseline CACS ≤ 100. CONCLUSION: The TyG index is an independent predictor of CAC progression, especially in adults without heavy baseline CAC.

The effect of combined Epidural-general Anesthesia on Hemodynamic Instability during Pheochromocytoma and Paraganglioma Surgery: A multicenter retrospective cohort study.

Objectives: The purpose of this study was to compare the effects of combined epidural-general anesthesia with those of general anesthesia alone on hemodynamic instability (intraoperative hypotension and hypertensive crisis) during pheochromocytoma and sympathetic paraganglioma surgery. Methods: A total of 119 patients' medical records were reviewed who were diagnosed as having pheochromocytoma and sympathetic paraganglioma on the basis of histological findings. Intraoperative hypotension was defined as a mean blood pressure < 60 mmHg or a decrease > 30% in baseline systolic blood pressure after adrenal vein ligation. Hypertensive crisis was defined as a systolic blood pressure > 200 mmHg or an increase > 30% in baseline systolic blood pressure during the operation. The predictor variables for intraoperative hypotension and hypertensive crisis were analyzed with logistic regression models. Data were presented as adjusted odds ratio with 95% confidence interval. Results: The independent predictors of intraoperative hypotension were an increased attenuation number on unenhanced computed tomography (1.112 [1.009-1.226], p = 0.033), a high baseline mean blood pressure (1.063 [1.012-1.117], p = 0.015), and the combined epidural-general anesthesia (5.439 [1.410-20.977], p = 0.014). In contrast, an increased attenuation number on unenhanced computed tomography was the only independent predictor of hypertensive crisis (1.087 [1.021-1.158], p = 0.009). Conclusions: The combined epidural-general anesthesia was not effective in attenuating hypertensive responses, but could have exacerbated intraoperative hypotension. These findings should be taken into account before selecting the anesthetic technique in pheochromocytoma and sympathetic paraganglioma surgery.

Triglyceride glucose index is a useful marker for predicting subclinical coronary artery disease in the absence of traditional risk factors.

BACKGROUND: Atherosclerotic cardiovascular (CV) events commonly occur in individuals with a low CV risk burden. This study evaluated the ability of the triglyceride glucose (TyG) index to predict subclinical coronary artery disease (CAD) in asymptomatic subjects without traditional CV risk factors (CVRFs). METHODS: This retrospective, cross-sectional, and observational study evaluated the association of TyG index with CAD in 1250 (52.8 ± 6.5 years, 46.9% male) asymptomatic individuals without traditional CVRFs (defined as systolic/diastolic blood pressure ≥ 140/90 mmHg; fasting glucose ≥126 mg/dL; total cholesterol ≥240 mg/dL; low-density lipoprotein cholesterol ≥160 mg/dL; high-density lipoprotein cholesterol < 40 mg/dL; body mass index ≥25.0 kg/m2; current smoking; and previous medical history of hypertension, diabetes, or dyslipidemia). CAD was defined as the presence of any coronary plaque on coronary computed tomographic angiography. The participants were divided into three groups based on TyG index tertiles. RESULTS: The prevalence of CAD increased with elevating TyG index tertiles (group I: 14.8% vs. group II: 19.3% vs. group III: 27.6%; P < 0.001). Multivariate logistic regression models showed that TyG index was associated with an increased risk of CAD (odds ratio [OR] 1.473, 95% confidence interval [CI] 1.026-2.166); especially non-calcified (OR 1.581, 95% CI 1.002-2.493) and mixed plaques (OR 2.419, 95% CI 1.051-5.569) (all P < 0.05). The optimal TyG index cut-off for predicting CAD was 8.44 (sensitivity 47.9%; specificity 68.5%; area under the curve 0.600; P < 0.001). The predictive value of this cut-off improved after considering the non-modifiable factors of old age and male sex. CONCLUSIONS: TyG index is an independent marker for predicting subclinical CAD in individuals conventionally considered healthy.

Emerging PEGylated non-biologic drugs.

Introduction: PEGylation is a well-established technology for improving the therapeutic value of drugs by attaching polyethylene glycol (PEG). The first PEGylated enzyme products appeared on the market in the early 1990s; currently, more than 18 PEGylated products have been approved by Food and Drug Administration, which encompass various classes of drug molecules, such as enzymes, interferons, granulocyte colony-stimulating factors, hormones, antibody fragments, coagulation factors, oligonucleotide aptamers, synthetic peptides, and small organic molecules. Areas covered: While PEGylated products mainly comprise biologic drugs, such as recombinant proteins and enzymes, non-biologic drugs have recently emerged as a target for PEGylation. This review focuses on the recent development of PEGylated non-biologic drugs, such as small organic molecules, synthetic peptides, and aptamers. Expert opinion: Several PEGylated versions of anti-cancer drugs, opioid agonists, glucagon-like peptide-1 receptor agonists, and oligonucleotide aptamers are in active development stage, and it is likely that they will have a dramatic impact on the market. Although some safety concerns about PEG in clinical trials have been recently issued, PEGylation is still a commercially attractive proposition as a half-life extension technology for long-acting drug development.

Nonstandard workers and differential occupational safety and health vulnerabilities.

BACKGROUND: Permanent jobs are in decline world-wide, and are being replaced with temporary, casual, part-time, and contract jobs. We investigated the characteristics and occupational safety and health (OSH) vulnerabilities of workers with nonstandard and standard employment. METHODS: We used the Korean Working Conditions Survey of 2017 to compare working conditions and OSH vulnerabilities of workers with standard and nonstandard employment in five major job categories. RESULTS: Workers with nonstandard employment were older, less educated, had lower monthly incomes, were employed in smaller businesses, worked fewer hours per week, had shorter work durations, and were more likely to report exposure to physical/chemical and ergonomic hazards, and musculoskeletal and mental symptoms. Among nonstandard workers, the rates of occupational hazards and work-related health problems depended on the type of work performed. In particular, nonstandard male workers who were unskilled manual workers, older, had less education, and earned low wages had a greater risk of working in unstable occupations, greater exposures to occupational hazards, and more musculoskeletal pain (back pain: odds ratio [OR], 2.4; upper extremity pain: OR, 2.1; and lower extremity pain: OR, 1.7) than those performing other types of work. CONCLUSION: Male unskilled manual workers with nonstandard employment were most vulnerable to OSH problems. Our findings suggest the need for OSH programs that specifically target nonstandard workers especially those in manual unskilled occupations.

Thymoquinone Selectively Kills Hypoxic Renal Cancer Cells by Suppressing HIF-1α-Mediated Glycolysis.

Several reports have shown that thymoquinone (TQ) effectively attenuates angiogenesis in cancer cells, resulting in suppression of tumor growth. However, it is not yet clear whether TQ reduces hypoxia-inducible factor-1α (HIF-1α) expression in hypoxic cancer cells. Here, we found that TQ was a novel HIF-1α inhibitor through hypoxia response element (HRE)-luciferase assay-based large screening by using 502 natural compounds containing chemical library. TQ reduced HIF-1α protein levels in renal cancer cells; however, it did not affect the HIF-1α protein levels in the presence of proteasome inhibitor, MG132, indicating that the reduction effects of TQ on HIF-1α protein are mediated via the ubiquitination-proteasome dependent pathway. TQ boosted HIF-1α protein degradation, and the mechanism was revealed by inhibiting interaction between HSP90 and HIF-1α. TQ suppressed downstream genes of HIF-1α, indicating negative impact of TQ on HIF-1α transcriptional activities. In addition, TQ altered glucose, lactate, and ATP levels, leading to anaerobic metabolic disturbance. TQ induced apoptosis in hypoxic cancer cells as determined by crystal violet staining and flow cytometry for annexin V-stained cells. Taken together, we suggested that TQ is a potential anticancer agent targeting HIF-1α.

Medication Nonadherence Increases Hepatocellular Carcinoma, Cirrhotic Complications, and Mortality in Chronic Hepatitis B Patients Treated With Entecavir.

OBJECTIVES: Optimal adherence to nucleoside analogue treatment is necessary to achieve undetectable levels of hepatitis B virus (HBV) DNA in patients with chronic hepatitis B (CHB), and to prevent cirrhotic complications. However, any large long-term follow-up study has not been investigated the effect of adherence to entecavir (ETV) treatment on specific liver-related events (LREs), namely, hepatocellular carcinoma (HCC), cirrhotic complications, and mortality. METHODS: This was a 10-year longitudinal observational study of treatment-naïve patients with CHB who received ETV treatment. The primary outcome was the cumulative probability of LREs. The cumulative level of adherence to medication was categorized as good (≥90%) or poor (<90%). RESULTS: Data from 894 treatment-naïve CHB patients who received ETV were analyzed. Overall mean adherence rates were 89.1%. Patients with poor adherence had a higher risk of virologic breakthrough (VBT) (HR, 22.42; 95% CI, 19.57-52.52; P < 0.001) than those with good adherence. Multivariate analyses showed a higher risk of liver-related (HR, 14.29; 95% CI, 3.49-58.47; P < 0.001) or all-cause (HR, 4.96; 95% CI, 2.19-11.27; P < 0.001) mortality, HCC (HR, 2.86; 95% CI, 1.76-4.64; P < 0.001), and cirrhotic complications (HR, 2.86; 95% CI, 1.93-4.25; P < 0.001) with poor adherence. Medication adherence was further stratified into three groups according to adherence rates of <70%, ≥70 to <90%, and ≥90%. The dose-response analyses of adherence rates showed that the risk of LREs increased progressively as medication adherence declined. In particular, the unfavorable effects of nonadherence were more pronounced in patients with cirrhosis. CONCLUSIONS: Poor adherence to medication was associated with a higher mortality and greater risk of HCC and cirrhotic complications, particularly among patients with liver cirrhosis.

Geographic variations in antibiotic prescription for pediatric acute upper respiratory tract infections in South Korea.

OBJECTIVE: This study aimed to investigate the factors affecting the geographic differences in antibiotic prescription rates in pediatric upper respiratory tract infections (URI) patients in South Korea. MATERIALS AND METHODS: We performed a nationwide cross-sectional study using 228 administrative districts of Korea, which are the unit of analysis. Prescription rate of antibiotics, the outcome variable, was measured as the proportion of antibiotic prescription days out of total visit days for the treatment of acute URIs using National Health Insurance Service (NHIS) claims data for 2012. Multivariate regression analysis was performed to identify factors affecting geographic variation in antibiotic prescription rates. RESULTS: The socioeconomic status of the district, as measured by the amount of local property tax payable and the proportion of individuals with higher level of education, were negatively correlated with prescription rate. The degree of competition in the hospital market within a district was positively associated with it. Patients living in areas with better access to family medicine physicians and those living in rural areas were less likely to use antibiotics to treat URIs. CONCLUSION: Our findings indicate the importance of considering demand factors as well as supply factors when developing intervention strategies for antibiotic overuse.
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Evaluation of Postoperative Stability After Open Reduction and Internal Fixation of Zygomaticomaxillary Complex Fractures Using Cone Beam Computed Tomography Analysis.

The aim of this study was to evaluate whether the amount of fracture displacement affects postoperative stability of isolated zygomaticomaxillary complex fractures and to determine whether the 1-point fixation method is as stable as 2- or 3-point fixation methods. The authors investigated 14 patients with 1-point fixation in the zygomaticomaxillary area (group A), 14 patients with 2-point fixation in the zygomaticomaxillary and frontozygomatic area (group B), and 13 patients with 3-point fixation in the zygomaticomaxillary, frontozygomatic, and infraorbital rim area (group C). Stability of the reduced zygomaticomaxillary complex was assessed by comparing immediate postoperative cone beam computed tomography images with those obtained at least 3 months later. Preoperatively, the total mean displacement was 3.79 ±â€Š1.36 mm in group A, 3.43 ±â€Š0.89 mm in group B, and 3.86 ±â€Š1.57 mm in group C. The total postoperative orbital and screw changes were 0.91 ±â€Š0.18 and 0.72 ±â€Š0.08 mm, respectively, in group A; 0.92 ±â€Š0.19 and 0.68 ±â€Š0.09 mm, respectively, in group B; and 0.91 ±â€Š0.11 and 0.66 ±â€Š0.10 mm, respectively, in group C. There were no significant relationships between postoperative stability and amount of fracture displacement in any of the 3 groups, or between the 3 groups (P > 0.05). There was little difference in postoperative stability between the 3 groups. Hence, the amount of displacement is not a very important consideration when deciding the fixation method, including the number and location of miniplates applied for fixation.

Cytotoxic effect of sanguiin H-6 on MCF-7 and MDA-MB-231 human breast carcinoma cells.

Sanguiin H-6 is a dimer of casuarictin linked by a bond between the gallic acid residue and one of the hexahydroxydiphenic acid units. It is an effective compound extracted from Rubus coreanus. It has an anticancer effect against several human cancer cells; however, its effect on breast cancer cells has not been clearly demonstrated. Thus, we aimed to investigate the anticancer effect and mechanism of action of sanguiin H-6 against two human breast carcinoma cell lines (MCF-7 and MDA-MB-231). We found that sanguiin H-6 significantly reduced cell viability in a concentration-dependent manner. It also increased the rates at which MCF-7 and MDA-MB-231 cells underwent apoptosis. Furthermore, sanguiin H-6 induced the cleavage of caspase-8, caspase-3, and poly(ADP-ribose) polymerase, which resulted in apoptosis. However, cleavage of caspase-9 was only detectable in MCF-7 cells. In addition, sanguiin H-6 increased the ratio of Bax to Bcl-2 in both MCF-7 and MDA-MB-231 cells. These findings suggest that sanguiin H-6 is a potent therapeutic agent against breast cancer cells. In addition, it exerts its anticancer effect in an estrogen-receptor-independent manner.

Vanillin Suppresses Cell Motility by Inhibiting STAT3-Mediated HIF-1α mRNA Expression in Malignant Melanoma Cells.

Recent studies have shown that vanillin has anti-cancer, anti-mutagenic, and anti-metastatic activity; however, the precise molecular mechanism whereby vanillin inhibits metastasis and cancer progression is not fully elucidated. In this study, we examined whether vanillin has anti-cancer and anti-metastatic activities via inhibition of hypoxia-inducible factor-1α (HIF-1α) in A2058 and A375 human malignant melanoma cells. Immunoblotting and quantitative real time (RT)-PCR analysis revealed that vanillin down-regulates HIF-1α protein accumulation and the transcripts of HIF-1α target genes related to cancer metastasis including fibronectin 1 (FN1), lysyl oxidase-like 2 (LOXL2), and urokinase plasminogen activator receptor (uPAR). It was also found that vanillin significantly suppresses HIF-1α mRNA expression and de novo HIF-1α protein synthesis. To understand the suppressive mechanism of vanillin on HIF-1α expression, chromatin immunoprecipitation was performed. Consequently, it was found that vanillin causes inhibition of promoter occupancy by signal transducer and activator of transcription 3 (STAT3), but not nuclear factor-κB (NF-κB), on HIF1A. Furthermore, an in vitro migration assay revealed that the motility of melanoma cells stimulated by hypoxia was attenuated by vanillin treatment. In conclusion, we demonstrate that vanillin might be a potential anti-metastatic agent that suppresses metastatic gene expression and migration activity under hypoxia via the STAT3-HIF-1α signaling pathway.

Plumbagin Suppresses α-MSH-Induced Melanogenesis in B16F10 Mouse Melanoma Cells by Inhibiting Tyrosinase Activity.

Recent studies have shown that plumbagin has anti-inflammatory, anti-allergic, antibacterial, and anti-cancer activities; however, it has not yet been shown whether plumbagin suppresses alpha-melanocyte stimulating hormone (α-MSH)-induced melanin synthesis to prevent hyperpigmentation. In this study, we demonstrated that plumbagin significantly suppresses α-MSH-stimulated melanin synthesis in B16F10 mouse melanoma cells. To understand the inhibitory mechanism of plumbagin on melanin synthesis, we performed cellular or cell-free tyrosinase activity assays and analyzed melanogenesis-related gene expression. We demonstrated that plumbagin directly suppresses tyrosinase activity independent of the transcriptional machinery associated with melanogenesis, which includes micropthalmia-associated transcription factor (MITF), tyrosinase (TYR), and tyrosinase-related protein 1 (TYRP1). We also investigated whether plumbagin was toxic to normal human keratinocytes (HaCaT) and lens epithelial cells (B3) that may be injured by using skin-care cosmetics. Surprisingly, lower plumbagin concentrations (0.5-1 µM) effectively inhibited melanin synthesis and tyrosinase activity but do not cause toxicity in keratinocytes, lens epithelial cells, and B16F10 mouse melanoma cells, suggesting that plumbagin is safe for dermal application. Taken together, these results suggest that the inhibitory effect of plumbagin to pigmentation may make it an acceptable and safe component for use in skin-care cosmetic formulations used for skin whitening.

Characterization of the Reversed-Phase Chromatographic Behavior of PEGylated Peptides Based on the Poly(ethylene glycol) Dispersity.

The separation mechanism of PEGylated peptides in reversed-phase high-performance liquid chromatography (RP-HPLC) is complex, because the PEGylated molecules exhibit physicochemical properties that are different from those of the parent molecules and have heterogeneous structure. Since most separation studies have focused on the hydrophobicity of the peptide relative to poly(ethylene glycol) (PEG), the role of PEG in the separation of PEGylated peptides on RP-HPLC is not clear. To elucidate the effect of the attached PEG on the retention of PEGylated peptides on RP-HPLC, the mono-PEGylated forms of collagen pentapeptide and octreotide were fractionated drop-by-drop from the outlet of the HPLC system and each drop was subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This approach demonstrated that the dispersity of the attached PEG leads to the peak broadness of PEGylated peptides in RP-HPLC and the elution order inside the HPLC peak of PEGylated peptides was dependent on the attached PEG chain length. The retention time of PEGylated peptide increased as the attached PEG chain increased in length. When uniform PEG was conjugated to octreotide, its well-resolved positional isomers of the mono-PEGylated forms showed narrow peaks comparable to native peptide peak under the same HPLC conditions, which confirmed the effect of the attached PEG dispersity on the chromatographic behavior of PEGylated peptides. In conclusion, this study indicates that the chromatographic behavior of PEGylated peptides is affected by the PEG chain length dispersity as well as the peptide's hydrophobicity.

Trimeric PEG-Conjugated Exendin-4 for the Treatment of Sepsis.

Exendin-4 (EX4), a glucagon-like peptide-1 receptor (GLP-1R) agonist that regulates blood glucose levels, has been used in the management of type-2 diabetes mellitus. EX4 can be PEGylated to improve its antidiabetic effects by enhancing its stability and extending the circulation half-life. Here, to determine whether PEGylated EX4 is effective for the treatment of sepsis, C-terminal thiol-specific PEGylated EX4s with linear maleimide-PEG-2K, -5K, -20K and trimeric maleimide-PEG-50K (hereafter referred to as EX4-2K, EX4-5K, EX4-20K, and EX4-50K, respectively) were prepared, and their antiseptic responses were investigated. These PEGylated EX4s reduced cecal ligation and puncture (CLP)-induced organ injury by decreasing hyperpermeability, and suppressing interactions between leukocytes and endothelial cells. The binding avidity and stability of EX4-50K toward GLP-1R were superior to that of wild-type EX4, as was the circulation half-life of EX4-50K. In addition, the antiseptic effects of EX4-50K were superior to those of other PEGylated EX4s, which may be attributed to enhanced proteolytic stability, longer circulation half-life, and higher receptor-binding affinity of EX4-50K due to its trimeric PEG structure. Therefore, EX4-50K may decrease CLP-induced septic mortality in vivo. There are currently neither effective preventatives against nor treatment options for sepsis; our results show that EX4-50K has the potential to treat sepsis.