Elevated serum gamma-glutamyltransferase is associated with an increased risk of oesophageal carcinoma in a cohort of 8,388,256 Korean subjects

Understanding heavy metal toxicity: Implications on human health, marine ecosystems and bioremediation strategies

Heavy metals are constituents of the natural environment and are of great importance to both natural and artificial processes. But in recent times the indiscriminate use of heavy metals especially for human purposes has caused an imbalance in natural geochemical cycles. This imbalance has caused contamination of heavy metals into natural resources and such as soil and a marine ecosystem. Long exposure and higher accumulation of given heavy metals are known to impose detrimental and even lethal effects on humans. Conventional remediation techniques of heavy metals provide good results but have negative side effects on surrounding environment. The role played by microbes in bioremediation of heavy metals is well reported in the literature and understanding the role of molecules in the process of metal accumulation its reduction and transformation into less hazardous state, has myriads of biotechnological implications for bioremediation of metal-contaminated sites. The current review presents the implications of heavy metals on human health and marine ecosystems, conventional methods of heavy metal removal and their side effects on the environment. Bioremediation approaches have been discussed as well in this review, proving to be a more sustainable and eco-friendly approach towards remediation of heavy metals.

Glutathione‑degrading enzymes in the complex landscape of tumors (Review)

Glutathione (GSH)‑degrading enzymes are essential for starting the first stages of GSH degradation. These enzymes include extracellular γ‑glutamyl transpeptidase (GGT) and intracellular GSH‑specific γ‑glutamylcyclotransferase 1 (ChaC1) and 2. These enzymes are essential for cellular activities, such as immune response, differentiation, proliferation, homeostasis regulation and programmed cell death. Tumor tissue frequently exhibits abnormal expression of GSH‑degrading enzymes, which has a key impact on the development and spread of malignancies. The present review summarizes gene and protein structure, catalytic activity and regulation of GSH‑degrading enzymes, their vital roles in tumor development (including regulation of oxidative and endoplasmic reticulum stress, control of programmed cell death, promotion of inflammation and tumorigenesis and modulation of drug resistance in tumor cells) and potential role as diagnostic biomarkers and therapeutic targets.

Gamma-glutamyl transpeptidase to platelet and gamma-glutamyl transpeptidase to lymphocyte ratio in a sample of Chinese Han population

BACKGROUND

Gamma-glutamyl transpeptidase to platelet ratio (GPR) and gamma-glutamyl transpeptidase to lymphocyte ratio (GLR) are assumed to be prognostic factors in liver fibrosis, cirrhosis and hepatocellular carcinoma. However, the reference values of GPR and GLR were not known.

OBJECTIVES

The study aimed to investigate the reference ranges of GPR and GLR in Chinese Han population in Chaoshan region in South China.

METHODS

A retrospective study was conducted in the First Affiliated Hospital of Shantou University Medical College in South China. 2400 healthy adults aged 20~79 years were included. GPR and GLR were determined.

RESULTS

Of 2400 healthy adults, 1200 men and 1200 women were included. The median GPR and GLR for men were 0.22 and 11.28, for women were 0.18 and 7.86, respectively. The 95% reference range of GPR in normal male and female are 0.09~0.54 and 0.08~0.55, GLR are 4.55~29.64 and 3.52~23.08, respectively. The male had a higher GPR at age 20~49 than the female while the GPR at age 60~79 was higher in the female than in the male. The GPR was affected by age, decreased with aging in male and increased in female. The GLR was higher in the male than in the female and varied with aging in the female but not in the male.

CONCLUSION

The study provides reference data on GPR and GLR from different age and sex groups in South China. GPR and GLR varied with age and sex.

The Association Between Cholecystectomy and the Risk for Fracture: A Nationwide Population-Based Cohort Study in Korea

Objectives

To evaluate the risk of fracture in individuals with a history of cholecystectomy in Korean population.

Methods

Individuals (n = 143,667) aged ≥ 40 y who underwent cholecystectomy between 2010 and 2015 and the controls (n = 255,522), matched by age and sex, were identified from the database of the Korean National Health Insurance Services. The adjusted hazard ratio (aHR) and 95% confidence interval (CI) of fracture were estimated following cholecystectomy, and a Cox regression analysis was performed.

Results

The incidence rates of all fractures, vertebral, and hip fractures were 14.689, 6.483 and 1.228 cases per 1000 person-years respectively in the cholecystectomy group, whereas they were 13.862, 5.976, and 1.019 cases per 1000 person-years respectively in the control group. After adjustment for age, sex, income, place of residence, diabetes mellitus, hypertension, dyslipidemia, smoking, alcohol drinking, exercise, and body mass index, patients who underwent cholecystectomy showed an increased risk of all fractures, vertebral fractures, and hip fractures (aHR [95% CI]: 1.095 [1.059-1.132], 1.134 [1.078-1.193], and 1.283 [1.139-1.444] for all fractures, vertebral fractures, and hip fractures, respectively). The risk of vertebral fractures following cholecystectomy was more prominent in the young age group (40 to 49 y) than in the old age group (≥ 65 y) (1.366 [1.082-1.724] vs. 1.132 [1.063-1.206], respectively). However, the incidence of hip fractures following cholecystectomy was not affected by age.

Conclusion

Individuals who underwent cholecystectomy have an increased risk of fracture. In the younger population, the risk of vertebral fractures may be further increased following cholecystectomy.

Risk of gastrointestinal cancer in patients with an elevated level of gamma-glutamyltransferase: A nationwide population-based study

Emerging evidence that an elevated serum gamma-glutamyltransferase (GGT) level is associated with an increased risk of gastrointestinal cancer, but still controversial. The aim of this study to assess the relationship between GGT level and risk of gastrointestinal cancer, and the contribution of the interaction of hyperglycemia with elevated GGT level to the incidence of gastrointestinal cancer by the stratified analysis. A total of 8,120,665 Koreans who received medical checkups in 2009 were included. Subjects were classified according to the quartile of GGT level for women and men. The incidence rates of gastrointestinal cancer for each group were analyzed using Cox proportional hazards models. During follow-up, 129,853 cases of gastrointestinal cancer newly occurred (esophagus, 3,792; stomach, 57,932; and colorectal, 68,789 cases). The highest GGT quartile group showed an increased risk of gastrointestinal cancer (esophagus, hazard ratio = 2.408 [95% confidence interval, 2.184–2.654]; stomach, 1.121 [1.093–1.149]; and colorectal, 1.185 [1.158–1.211]). The risk increased significantly with the rise in GGT quartile level, regardless of the site of cancer. The stratified analysis according to glycemic status showed that the effect of elevated GGT was predominant in the risk of esophageal cancer. The effect of elevated GGT further increased the risk of stomach and colorectal cancers in diabetic patients. An elevated level of GGT was associated with an increased risk of gastrointestinal cancer, regardless of the site of cancer. The effect of the increase in GGT level on the risk of gastrointestinal cancer depended on the type of cancer and glycemic status.

Repeatedly elevated γ-glutamyltransferase levels are associated with an increased incidence of digestive cancers: A population-based cohort study

BACKGROUND

The association between elevated γ-glutamyltransferase (GGT) at a certain point and incident cancer has been suggested; however, no study has evaluated the association between repeatedly elevated GGT and cancer incidence.

AIM

To investigate the effects of repeatedly elevated GGT on the incidence of digestive cancers.

METHODS

Participants who had undergone health screening from 2009 to 2012 and 4 consecutive previous examinations were enrolled. GGT points were calculated as the number of times participants met the criteria of quartile 4 of GGT in four serial measurements (0-4 points). Multivariable Cox proportional hazard regression models were applied.

RESULTS

In total, 3559109 participants were included; among them, 43574 digestive cancers developed during a median of 6.8 years of follow-up. The incidence of total digestive cancers increased in a dose-response manner in men [adjusted hazard ratio (aHR) compared with those with 0 GGT points = 1.28 and 95% confidence interval (CI) = 1.24-1.33 in those with 1 point; aHR = 1.40 and 95%CI = 1.35-1.46 in those with 2 points; aHR = 1.52 and 95%CI = 1.46-1.58 in those with 3 points; aHR = 1.88 and 95%CI = 1.83-1.94 in those with 4 points; P for trend < 0.001]. This trend was more prominent in men than in women and those with healthy habits (no smoking, no alcohol consumption, and a low body mass index) than in those with unhealthy habits.

CONCLUSION

Repeatedly elevated GGT levels were associated with an increased risk of incident digestive cancer in a dose-responsive manner, particularly in men and those with healthy habits. Repeated GGT measurements may be a good biomarker of incident digestive cancer and could help physicians identify high-risk populations.

A two-photon fluorescent probe for sensitive detection and imaging of γ-glutamyl transpeptidase

A GGT-activated two-photon fluorescent probe (4F-2CN-GSH) was developed based on a cascade reaction. 4F-2CN-GSH could selectivily detect GGT with low detection limit and distinguish ovarian cancer cells from normal cells using both one-photon and two-photon fluorescence imaging.

Abdominal obesity increases risk for esophageal cancer: a nationwide population-based cohort study of South Korea

BACKGROUND

The relationship between overall obesity, as measured by body mass index (BMI) and risk of esophageal squamous cell carcinoma (ESCC) has been reported to show a negative correlation. However, the relationship of ESCC, which accounts for around 90% of esophageal cancers in South Korea, with abdominal obesity, as measured by waist circumference (WC), may be different. Thus, we investigated the association between abdominal obesity and esophageal cancer in a nationwide population-based cohort.

METHODS

A retrospective cohort study of 22,809,722 individuals who had undergone regular health check-ups provided by the National Health Insurance Corporation between 2009 and 2012 (median follow-up period, 6.4 years) in South Korea was conducted. Abdominal obesity was defined as a WC > 90 cm for men and > 85 cm for women. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using χ² test and Cox proportional hazards model adjusted for confounding factors. The primary outcome was newly developed esophageal cancer.

RESULTS

After adjusting for BMI, abdominal obesity increased the risk of esophageal cancer (HR 1.29, 95% CI 1.23-1.36). WC increased the risk for esophageal cancer in a dose-dependent manner (p values for trend < 0.0001). Among overweight (BMI 23-24.9 kg/m²) and obese I (BMI 25-29.9 kg/m²) individuals, abdominal obesity was a risk factor for esophageal cancer (HR 1.22, 95% CI 1.11-1.34; HR 1.28, 95% CI 1.18-1.39, respectively).

CONCLUSION

Increasing abdominal obesity may be associated with an increased risk for esophageal cancer. Further studies are warranted to confirm the relationship.

Determination of the activity of γ-glutamyl transpeptidase and of its inhibitors by using the inner filter effect on the fluorescence of nitrogen-doped carbon dots

A fluorescence (FL) probe for determination of γ-glutamyl transpeptidase (GGT) activity and evaluation of inhibitors was developed based on the inner filter effect (IFE) of nitrogen-doped carbon dots (N-CDs). Bright green emissive N-CDs were synthesized by one-step hydrothermal technique with catechol and ethylenediamine. The excitation and emission wavelengths for N-CDs were 408 and 510 nm, respectively. γ-L-Glutamyl-4-nitroanilide (γ-G4NA) was employed as the substrate of GGT. The absorption spectrum of GGT catalytic product (4-nitroaniline, 4-NA) overlapped greatly with the excitation spectrum of N-CDs. 4-NA acted as the absorber in IFE to quench the FL of N-CDs. Thus, the FL quenching of N-CDs was closely related to GGT activity. The established FL method offered good linear relationship within 2.0-10.0 U L^-1 (R², 0.982) and 10.0-110.0 U L^-1 (R², 0.998) with a low detection limit of 0.6 U L^-1. The method was successfully applied to investigate GGT activity in human serum samples with acceptable recoveries (99.1-105.0%). The approach was also employed for screening GGT inhibitors from different polar extracts of Schisandra chinensis. Results indicated that this strategy presents superior characteristics for GGT sensing. This method has great potential as a candidate for diagnosis of GGT-related diseases and high-throughput drug discovery. Graphical abstract.

The association between nonalcoholic fatty liver disease and esophageal, stomach, or colorectal cancer: National population-based cohort study

We investigated the association between nonalcoholic fatty liver disease (NAFLD) and gastrointestinal tract cancer in the general population. Retrospective data on individuals aged ≥20 years who received healthcare checkups from January 1, 2009 to December 31, 2009 were analyzed using the National Health Insurance Database in Korea. NAFLD was defined based on the fatty liver index (FLI ≥60). The primary outcome was newly diagnosed esophageal, stomach, or colorectal cancer using ICD-10 codes during follow-up until 31 December 2017. Cox regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs). Among 8,120,674 subjects, 936,159 adults (11.5%) were identified as having NAFLD. Their mean age was 46.7 ± 14.1 years, and 52.1% were male. During the follow-up period (7.2 years), 3,792 esophageal, 57,292 stomach and 68,769 colorectal cancer cases were identified. FLI ≥60 was significantly associated with the development of esophageal (HR 2.10, 95% CI 1.88-2.35), stomach (HR 1.18, 95% CI 1.14-1.22), and colon cancer (HR, 1.23, 95% CI 1.19-1.26) after multivariable adjustment. Compared to subjects without NAFLD, all-cause mortality in patients with esophageal (HR 1.46, 95% CI 1.28-1.67), stomach (HR 1.26, 95% CI 1.18-1.34), and colorectal cancer (HR 1.16, 95% CI 1.10-1.22) was significantly increased in subjects with NAFLD (FLI ≥60). NAFLD defined using FLI was a good predictive indicator for GI tract malignancy and all-cause mortality in the general population. Subjects with NAFLD are needed for active surveillance of esophageal, stomach, and colorectal cancers.

Gamma-glutamyltransferase as a preoperative differential diagnostic marker in patients with adnexal mass

OBJECTIVE

Gamma-glutamyltransferase (GGT) is involved in tumor development, progression and chemotherapy resistance. The present study evaluated GGT serum levels as a preoperative predictive marker for ovarian cancer in patients with adnexal mass.

STUDY DESIGN

Preoperative GGT serum levels of 2235 patients with adnexal mass and subsequent surgery were ascertained (patients with benign ovarian tumors: n = 1811; borderline tumor of the ovary [BTO]: n = 85; epithelial ovarian cancer [EOC]: n = 339). Standardized expert transvaginal ultrasound was documented.

RESULTS

Median (interquartile range) GGT serum levels in patients with benign ovarian tumors, BTO, and EOC were 15.0 U/l (11.0-23.0), 17.0 U/l (10.0-23.5), and 20.0 U/l (13.0-34.0), respectively (p = 0.002). Elevated GGT serum levels were associated with the presence of BTO/EOC in univariate analysis (p < 0.0001, hazard ratio 1.8, confidence interval 1.5-2.3). GGT did not outperform established tools for preoperative prediction of BTO/EOC in patients with adnexal mass, such as CA-125 measurement or transvaginal ultrasound.

CONCLUSION

Elevated GGT serum levels were not associated with the presence of BTO/EOC in women with suspicious adnexal mass in multivariate analysis. GGT serum levels did not outperform established risk factors and therefore might add only limited additional value to CA-125 serum levels in the differential diagnosis between benign and malignant adnexal masses.

Adult height in relation to risk of cancer in a cohort of 22,809,722 Korean adults

Background

The present study examined whether adult height was associated with all site-combined or site-specific cancers.

Methods

We used a nationwide claim data of 22,809,722 Korean participants including both men and women (2009–2012). The deciles of height from different age and sex groups were merged into a new quintile. We used Cox proportional hazards model to estimate hazard ratios (HRs) and 95% confidence intervals.

Results

During a 5-year follow-up period, 765,651 patients were diagnosed with cancer. Height was positively associated with risk of all site-combined cancers and with malignancy in the oral cavity, larynx, lung, stomach, colorectum, liver, pancreas, biliary tract and gallbladder, breast, ovary, cervix and corpus uteri, prostate, testes, kidney, bladder, central nervous system, thyroid, skin, and lymphatic and haematopoietic systems. The HRs for all-site cancers per 5 cm increment in height was 1.09 and that of each site was the highest in thyroid, breast, lymphoma, testicular, and renal cancers. This association was more prominent in women and male non-smokers than in other counterparts.

Conclusions

Taller adult height was significantly related to an increased risk of most cancers including neoplasm in the gallbladder or biliary tract and testes, but except for oesophagus.

Recent Advances in the Development of Optical Imaging Probes for γ-Glutamyltranspeptidase

γ-Glutamyltranspeptidase (GGT) is a cell-membrane-bound protease that participates in cellular glutathione and cysteine homeostasis, which are closely related to many physiological and pathological processes. The accurate measurement of GGT activity is useful for the early diagnosis of diseases. In the past few years, many efforts have been made to build optical imaging probes for the detection of GGT activity both in vitro and in vivo. In this Minireview, recent advances in the development of various optical imaging probes for GGT, including activatable fluorescence probes, ratiometric fluorescence probes, and activatable bioluminescence probes, are summarized. This review starts from the instruction of the GGT enzyme and its biological functions, followed by a discussion of activatable fluorescence probes that show off-on fluorescence in response to GGT. GGT-activatable two-photon fluorescence imaging probes with improved imaging depth and spatial resolution are also discussed. Ratiometric fluorescence probes capable of accurately reporting on GGT levels through a self-calibration mechanism are discussed, followed by describing GGT-activatable bioluminescence probes that can offer a high signal-to-background ratio to detect GGT in living mice. Finally, current challenges and further perspectives for the development of molecular imaging probes for GGT are addressed.