Association of gamma-glutamyltransferase with severity of disease at diagnosis and prognosis of ovarian cancer

Biotin-tagged fluorescent probe for in situ visualization of γ-glutamyl transpeptidase in cancerous cells and tissues

γ-Glutamyl transpeptidase (GGT), a cell-surface enzyme, is strongly implicated in mammalian malignancy growth and migration processes including human hepatocarcinogens. However, simply and conveniently detect of GGT on the cell membrane remains highly challenging. In this study, a biotin-tagged fluorescent probe Nap-biotin-glu was developed using glutamic acid, naphthalimide, and biotin as the reaction site, fluorescent reporter, and membrane-targeting group, which required only three steps. Colocalization fluorescence imaging and immunofluorescence analysis indicated that probe Nap-biotin-glu was successfully realized in situ visualizing of GGT on the cell membrane.Owing to the significant over-expressed GGT level in tumor, the probe was successfully applied to distinguish cancer tissues from adjacent normal tissues.

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.

GGT5: a potential immunotherapy response inhibitor in gastric cancer by modulating GSH metabolism and sustaining memory CD8+ T cell infiltration

PURPOSE

The variable responses to immunotherapy observed in gastric cancer (GC) patients can be attributed to the intricate nature of the tumor microenvironment. Glutathione (GSH) metabolism significantly influences the initiation and progression of gastric cancer. Consequently, targeting GSH metabolism holds promise for improving the effectiveness of Immune checkpoints inhibitors (ICIs).

METHODS

We investigated 16 genes related to GSH metabolism, sourced from the MSigDB database, using pan-cancer datasets from TCGA. The most representative prognosis-related gene was identified for further analysis. ScRNA-sequencing analysis was used to explore the tumor heterogeneity of GC, and the results were confirmed by  Multiplex immunohistochemistry (mIHC).

RESULTS

Through DEGs, LASSO, univariate and multivariate Cox regression analyses, and survival analysis, we identified GGT5 as the hub gene in GSH metabolism with the potential to promote GC. Combining CIBERSORT, ssGSEA, and scRNA analysis, we constructed the immune architecture of GC. The subpopulations of T cells were isolated, revealing a strong association between GGT5 and memory CD8+ T cells. Furthermore, specimens from 10 GC patients receiving immunotherapy were collected. mIHC was used to assess the expression levels of GGT5 and memory CD8+ T cell markers. Our results established a positive correlation between GGT5 expression, the enrichment of memory CD8+ T cells, and a suboptimal response to immunotherapy.

CONCLUSIONS

Our study identifies GGT5, a hub gene in GSH metabolism, as a potential therapeutic target for inhibiting the response to immunotherapy in GC patients. These findings offer new insights into strategies for optimizing immunotherapy of GC.

Receptor mediated targeting of EGF-conjugated alginate-PAMAM nanoparticles to lung adenocarcinoma: 2D/3D in vitro and in vivo evaluation

Carboplatin (cis-diamine (1,1-cyclobutandicarboxylaso)‑platinum (II)) is a second-generation antineoplastic drug, which is widely used for chemotherapy of lung, colon, breast, cervix, testicular and digestive system cancers. Although preferred over cisplatin due to the lower incidence of nephrotoxicity and ototoxicity, efficient carboplatin delivery remains as a major challenge. In this study, carboplatin loaded alginate- poly(amidoamine) (PAMAM) hybrid nanoparticles (CAPs) with mean sizes of 192.13 ± 4.15 nm were synthesized using a microfluidic platform, then EGF was conjugated to the surface of CAPs (EGF-CAPs) for the receptor-targeted delivery. Hence, increased FITC+ cell counts were observed in A549 spheroids after EGF-CAP treatment compared to CAP in the 3D cellular uptake study. As such, the cytotoxicity of EGF-CAP was approximately 2-fold higher with an IC50 value of 35.89 ± 10.37 μg/mL compared to the CAPs in A549 spheroids. Based on in vivo experimental animal model, anti-tumor activities of the group treated with CAP decreased by 61 %, whereas the group treated with EGF-CAP completely recovered. Additionally, EGF-CAP application was shown to induce apoptotic cell death. Our study provided a new strategy for designing a hybrid nanoparticle for EGFR targeted carboplatin delivery with improved efficacy both in vitro and in vivo applications.

Does gamma-glutamyltransferase correlate with liver tumor burden in neuroendocrine tumors?

PURPOSE

In patients with neuroendocrine tumors (NETs) and liver metastases, increased gamma-glutamyltransferase (GGT) is commonly assumed as an indicator for progressive disease. To date, however, empirical data are lacking. This study aimed to investigate associations between GGT and liver tumor burden. In longitudinal analyses, associations of GGT and radiographic responses of liver metastases under therapy were investigated.

METHODS

The cross-sectional sample consisted of 104 patients who were treated at the University Medical Center Hamburg-Eppendorf from 2008 to 2021 (mean age 62.3 ± 12.6 years, 58.7% male). GGT and liver imaging were identified in a time range of 3 months. Radiologic reassessments were performed to estimate liver tumor burden. In a separate longitudinal sample (n = 15), the course of GGT levels under chemotherapy was analyzed. Data were retrospectively analyzed with a univariate ANOVA, linear regression analyses, and Wilcoxon tests.

RESULTS

Of 104 cross-sectionally analyzed patients, 54 (51.9%) showed a GGT elevation. GGT levels and liver tumor burden were positively correlated (p < 0.001), independently from age, gender, primary tumor location, grading, and cholestasis. Notably, GGT increase was associated with a liver tumor burden of >50%. In the longitudinal sample, 10 of 11 patients with progressive disease showed increasing GGT, whereas 4 of 4 patients with regressive disease showed declining GGT.

CONCLUSION

Our findings indicate that GGT is associated with liver tumor burden. Over the course of therapy, GGT appears to change in line with radiographic responses. Further longitudinal studies with larger sample sizes are required to define GGT as a reliable marker for tumor response.

Association between serum gamma-glutamyltransferase and early-onset coronary artery disease: a retrospective case-control study

BACKGROUND

Serum gamma-glutamyltransferase (GGT) activity has been proposed as a promising predictor of atherosclerosis-related complications and a prognostic marker for cardiovascular diseases. The objective of this study was to investigate the potential correlation between serum levels of GGT and early-onset coronary artery disease (EOCAD).

METHODS

A retrospective, hospital-based case-control study was conducted, which included 860 patients with EOCAD and gender- and age-matched controls. Serum levels of GGT were measured using the reference measurement procedure on an automatic biochemistry analyser.

RESULTS

The serum GGT levels of patients with EOCAD (34.90 ± 31.44 U/L) were significantly higher than those of the control group (21.57 ± 16.44 U/L, p < .001). Elevated serum levels of GGT were found to be an independent risk factor for EOCAD, with an odds ratio (OR) of 1.021 (95% confidence interval (CI): 1.014-1.029). Additionally, for every quartile increase in serum GGT levels, the risk of developing EOCAD increased by 1.6-fold. Moreover, serum GGT levels were significantly associated with disease severity, with lower GGT levels observed in patients without significant vascular disease (31.74 ± 24.06 U/L) compared to those with two-vessel disease (33.06 ± 25.00 U/L, p = .002) and three-vessel disease (37.75 ± 36.76 U/L, p = .001).

CONCLUSIONS

The results of this study suggest that elevated serum GGT levels are associated with the development of EOCAD, and GGT may be implicated in the pathogenesis of the disease. Further large-scale prospective studies are needed to explore the potential relationship between serum GGT levels and the dynamic development of EOCAD.

γ-Glutamyltranspeptidase-Activated Near-Infrared fluorescent probe for visualization of Drug-Induced liver injury

Drug-induced liver injury (DILI), induced by overdose or chronic administration of drugs, has become the leading cause of acute liver failure. Therefore, an accurate diagnostic method for DILI is critical to improve treatment efficiency. The production of γ-glutamyltranspeptidase (GGT) is closely related to the progression of drug-induced hepatotoxicity. KL-Glu exhibits a prominent GGT-activated NIR fluorescence (734 nm) with a large Stokes shift (137 nm) and good sensitivity/selectivity, making it favorable for real-time detection of endogenous GGT activity. Using this probe, we evaluated the GGT up-regulation under the acetaminophen-induced liver injury model. Moreover, KL-Glu was successfully used to assess liver injury induced by the natural active ingredient triptolide and the effective amelioration upon treatment with N-acetyl cysteine (NAC) or Glutathione (GSH) in cells and in vivo by fluorescent trapping the fluctuation of GGT for the first time. Therefore, the fluorescent probe KL-Glu can be used as a potential tool to explore the function of GGT in the progression of DILI and for the early diagnosis and prognostic evaluation of DILI.

MicroRNA-142-3p promotes renal cell carcinoma progression by targeting RhoBTB3 to regulate HIF-1 signaling and GGT/GSH pathways

MicroRNAs play a critical regulatory role in different cancers, but their functions in renal cell carcinoma (RCC) have not been elucidated. Reportedly, miR-142-3p is involved in the tumorigenesis and the development of RCC in vitro and is clinically correlated with the poor prognosis of RCC patients. However, the molecular target of miR-142-3p and the underlying mechanism are unclear. In this study, we found that miR-142-3p was upregulated in RCC tumor tissues and downregulated in exosomes compared to normal tissues. The expression of miR-142-3p was inversely associated with the survival of patients with kidney renal clear cell carcinoma (KIRC). RhoBTB3 was reduced in RCC, and miR-142-3p plays an inverse function with RhoBTB3 in KIRC. The direct interaction between RhoBTB3 and miR-142-3p was demonstrated by a dual luciferase reporter assay. miR-142-3p promoted metastasis in the xenograft model, and the suppression of miR-142-3p upregulated RhoBTB3 protein expression and inhibited the mRNAs and proteins of HIF1A, VEGFA, and GGT1. Also, the miR-142-3p overexpression upregulated the mRNA of HIF1A, VEGFA, and GGT1. In conclusion, miR-142-3p functions as an oncogene in RCC, especially in KIRC, by targeting RhoBTB3 to regulate HIF-1 signaling and GGT/GSH pathways, which needs further exploration.

Imaging of a novel ratio γ-glutamyl transpeptidase fluorescent probe in living cells and biopsies

Herein, a novel fluorescent probe, GTP, was developed for monitoring the GGT (γ-glutamyl transpeptidase) level in living cells and biopsies. It consisted of the typical recognition group γ-Glu (γ-Glutamylcysteine) and the fluorophore (E)-4-(4-aminostyryl)-1-methylpyridin-1-ium iodide. With a ratio response between the signal intensity at 560 nm and 500 nm (R_I560/_I500), it could be important complement for the turn-on ones. With the linear range of 0-50 U/L, the limit of detection was calculated as 0.23 μM. The detection system showed the strongest response near pH 7.4, and exhibited steady fluorescence signals for at least 48 h. With high selectivity, good anti-interference and low cytotoxicity, GTP was suitable for physiological applications. By monitoring the GGT level with the ratio values in the green and blue channels, the probe GTP could distinguish cancer cells from normal cells. Furthermore, in the mouse tissues and humanization tissue samples, the probe GTP could also recognize the tumor tissues from the normal ones.

A water-soluble fluorescent probe for the determination of γ-glutamyltransferase activity and its application in tumor imaging

γ-glutamyltransferase (GGT), an important tumor marker, is highly expressed in tumor tissues, and precise detection of its activity provides a vital indicator for the diagnosis and treatment. In this work, a "lighting-on" probe (TCF-GGT) was elaborated to detect endogenous GGT with high selectivity and sensitivity. Dicyanomethyldifuranyl (TCF-OH) was employed as the fluorescence reporter and short peptide glutathione (GSH) worked as the GGT-active trigger, the introduction of which prevented the initial proton transfer of TCF-OH contributing to a blank sensing background. A bright red fluorescence could be switched on upon GGT catalytic hydrolysis, avoiding the potential interference from background. There displayed an excellent water-solubility, and little organic solvent was required during the exploration, which otherwise avoided the potential damage to enzyme and organism. TCF-GGT has been proved to be workable at cellular and organism level with highly effective imaging and a short metabolic cycle, which is expected to offer an alternative solution or reference to the early diagnosis and treatment of tumor.

γ-Glutamyltransferase-Activatable Fluoro-Photoacoustic Reporter for Highly Sensitive Diagnosis of Acute Liver Injury and Tumor

γ-Glutamyltransferase (GGT) has been recognized as an important clinical biomarker that is closely related to many diseases. Visualizing the GGT fluctuation facilitates early disease-related diagnosis and therapy. Herein, an activated probe (NIR-GGT) for the imaging of GGT activity was prepared. The probe consists of a stable NIR fluorophore with the tunable amino group decorated with the γ-glutamate group as a GGT-sensing unit linked by a self-elimination group. NIR-GGT can sensitively recognize GGT and cause a strong turn-on fluorescent and photoacoustic signal. The up-regulation of the GGT expression in acetaminophen-induced acute liver injury was imaged using NIR-GGT. The probe can track changes in the GGT level in the early stages of drug-induced acute liver injury (DIALI) and its remedy process by fluorescent and photoacoustic dual-modality imaging with a high temporal-spatial resolution. NIR-GGT can also be used to differentiate between tumor and para-carcinowa tissues in vivo. The probe may be a potential tool for the diagnosis of early-stage DIALI and accurate tumor resection in the clinical field.

Metabolomic profile of prostate cancer-specific survival among 1812 Finnish men

BACKGROUND

Abnormal metabolism and perturbations in metabolic pathways play significant roles in the development and progression of prostate cancer; however, comprehensive metabolomic analyses of human data are lacking and needed to elucidate the interrelationships.

METHODS

We examined the serum metabolome in relation to prostate cancer survival in a cohort of 1812 cases in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. Using an ultrahigh-performance LC-MS/MS platform, we identified 961 known metabolites in prospectively collected serum. Median survival time from diagnosis to prostate cancer-specific death (N=472) was 6.6 years (interquartile range=2.9-11.1 years). Cox proportional hazards regression models estimated hazard ratios and 95% confidence intervals of the associations between the serum metabolites (in quartiles) and prostate cancer death, adjusted for age at baseline and diagnosis, disease stage, and Gleason sum. In order to calculate risk scores, we first randomly divided the metabolomic data into a discovery set (70%) and validated in a replication set (30%).

RESULTS

Overall, 49 metabolites were associated with prostate cancer survival after Bonferroni correction. Notably, higher levels of the phospholipid choline, amino acid glutamate, long-chain polyunsaturated fatty acid (n6) arachidonate (20:4n6), and glutamyl amino acids gamma-glutamylglutamate, gamma-glutamylglycine, and gamma-glutamylleucine were associated with increased risk of prostate cancer-specific mortality (fourth versus first quartile HRs=2.07-2.14; P-values <5.2×10^-5). By contrast, the ascorbate/aldarate metabolite oxalate, xenobiotics S-carboxymethyl-L-cysteine, fibrinogen cleavage peptides ADpSGEGDFXAEGGGVR and fibrinopeptide B (1-12) were related to reduced disease-specific mortality (fourth versus first quartile HRs=0.82-0.84; P-value <5.2×10^-5). Further adjustment for years from blood collection to cancer diagnosis, body mass index, smoking intensity and duration, and serum total and high-density lipoprotein cholesterol did not alter the results. Participants with a higher metabolic score based on the discovery set had an elevated risk of prostate cancer-specific mortality in the replication set (fourth versus first quartile, HR=3.9, P-value for trend<0.0001).

CONCLUSIONS

The metabolic traits identified in this study, including for choline, glutamate, arachidonate, gamma-glutamyl amino acids, fibrinopeptides, and endocannabinoid and redox pathways and their composite risk score, corroborate our previous analysis of fatal prostate cancer and provide novel insights and potential leads regarding the molecular basis of prostate cancer progression and mortality.

Gamma-Glutamyltransferase Activity (GGT) Is a Long-Sought Biomarker of Redox Status in Blood Circulation: A Retrospective Clinical Study of 44 Types of Human Diseases

Background and Aim. Redox equilibria are critical for life, but the biomarkers of redox status are currently unavailable. Gamma-glutamyltransferase (GGT) is an essential factor for modulating redox equilibrium through glutathione. In clinical practice, increased circulating GGT activity is used as a hepatobiliary disease biomarker. However, increased circulating GGT activities have also been observed in cancers, heart disease, diabetes, hyperuricemia, inflammation, renal insufficiency, and other diseases, explained by its role in maintaining redox equilibrium inside and outside cells. Previous studies on GGT were mainly limited to one type of disease at one time. In the current study, we systematically compared the GGT levels in 44 different human diseases to test if it could serve as a redox status biomarker in blood circulation. Methods. The clinical GGT data from 168,858 patients with 44 diseases and 132,357 healthy control in the clinical laboratory of our hospital over the past five years were retrieved. All data were analyzed with SPSS, RStudio V.1.3.1073, and python libraries 3.8. Results. Thirty-eight out of 44 diseases had significantly increased ( $p<0.001$ ) circulating GGT activities, whereas gastric cancer, anemia, renal cyst, cervical cancer, preeclampsia, and knee-joint degenerative diseases had significantly decreased ( $p<0.001$ ) GGT activities compared to the healthy control. ROC analyses showed that GGT was an excellent biomarker for liver cancer ( $\text{AUC}=0.86$ ), pancreatitis ( $\text{AUC}=0.84$ ), or hepatic encephalopathy ( $\text{AUC}=0.80$ ). All pancreas-related diseases had more than 8-fold increases in GGT activity span than the healthy control, while pancreatic cancer had a 12-fold increase (1021 U/L vs. 82 U/L). The knee-joint degenerative disease had the lowest median and narrowest GGT activity range (63 U/L). Furthermore, most diseases’ lowest to highest GGT activities were beyond the healthy control in both directions. Conclusions. Thirty-eight out of 44 diseases were in overall oxidative states defined by the increased GGT median values. In contrast, knee-joint degenerative disease, gastric cancer, anemia, renal cyst, cervical cancer, and preeclampsia were in overall antioxidative states. Moreover, most diseases swing between oxidative and antioxidative states, evidenced by the increased lowest to highest GGT activity ranges than the healthy control. Liver- and pancreas-related abnormalities were responsible for significantly increased GGT activities. Our overall results suggested that circulating GGT was a redox status biomarker.

Optimized molecular design of PET probe for the visualization of γ-glutamyltranspeptidase activity in tumors

A fluorine-18 labeled probe [18F]JM-10 was rationally designed and optimized, which can self-assemble to generate more rigid and hydrophobic dimers upon response to γ-glutamyltranspeptidase (GGT) and glutathione (GSH) in tumor cells.

Targeting multidrug resistance-associated protein 1 (MRP1)-expressing cancers: Beyond pharmacological inhibition

Resistance to chemotherapy remains one of the most significant obstacles to successful cancer treatment. While inhibiting drug efflux mediated by ATP-binding cassette (ABC) transporters is a seemingly attractive and logical approach to combat multidrug resistance (MDR), small molecule inhibition of ABC transporters has so far failed to confer clinical benefit, despite considerable efforts by medicinal chemists, biologists, and clinicians. The long-sought treatment to eradicate cancers displaying ABC transporter overexpression may therefore lie within alternative targeting strategies. When aberrantly expressed, the ABC transporter multidrug resistance-associated protein 1 (MRP1, ABCC1) confers MDR, but can also shift cellular redox balance, leaving the cell vulnerable to select agents. Here, we explore the physiological roles of MRP1, the rational for targeting this transporter in cancer, the development of small molecule MRP1 inhibitors, and the most recent developments in alternative therapeutic approaches for targeting cancers with MRP1 overexpression. We discuss approaches that extend beyond simple MRP1 inhibition by exploiting the collateral sensitivity to glutathione depletion and ferroptosis, the rationale for targeting the shared transcriptional regulators of both MRP1 and glutathione biosynthesis, advances in gene silencing, and new molecules that modulate transporter activity to the detriment of the cancer cell. These strategies illustrate promising new approaches to address multidrug resistant disease that extend beyond the simple reversal of MDR and offer exciting routes for further research.

Liver enzymes and risk of ocular motor cranial nerve palsy: a nationwide population-based study

This study aimed to assess the associations between liver enzymes including γ-glutamyl transferase (GGT) and the development of ocular motor cranial nerve palsy (CNP) using the National Sample Cohort database from Korea's National Health Insurance Service. We analyzed data from 4,233,273 medical screening examinees aged 20 years or more in 2009. Study participants were followed up until December 31, 2018. A Cox proportional hazard regression analysis was performed for quartiles of liver enzymes to determine the linkage between each value and ocular motor CNP using quartile 1 as a reference after adjusting for potential confounders. A total of 5,807 (0.14%) patients developed ocular motor CNP during the follow-up period of 8.22 ± 0.94 years. The incidence of ocular motor CNP gradually increased as the GGT levels increased. The highest quartile of the GGT group had hazard ratio (HR) of 1.245 (95% confidence interval [CI], 1.136-1.365). Regarding alanine aminotransferase (ALT), the highest quartile of the ALT group had HR of 1.141 (95% CI, 1.049-1.241). However, the incidence of ocular motor CNP did not gradually increase as the ALT levels increased. The coexistence of the increased level of GGT, metabolic syndrome, and obesity showed a stronger association with ocular motor CNP development (HR, 1.331; 95% CI, 1.173, 1.511) compared to having a single factor or two factors. In conclusion, our population-based cohort study demonstrated a significant association between serum GGT level and the incidence of ocular motor CNP, suggesting that GGT could be a new clinical marker for predicting the occurrence of ocular motor CNP.

Impact of Serum γ-Glutamyltransferase on Overall Survival in Men with Metastatic Castration-Resistant Prostate Cancer Treated with Docetaxel

Simple Summary

γ-Glutamyltransferase (GGT) is a biomarker of oxidative stress and its elevation in the serum is linked to poor survival in various malignancies; however, reports on metastatic castration-resistant prostate cancer (mCRPC) are scarce. Moreover, the source of serum GGT in men with mCRPC is largely unknown. The aims of this study were to determine the impact of serum GGT on overall survival in men with mCRPC receiving docetaxel therapy, and to examine the association between systemic and local GGT levels using immunohistochemistry. Of note, high serum GGT was associated with adverse overall survival as were low hemoglobin and high prostate-specific antigen levels. Additionally, tissue GGT expression status in prostate specimens was moderately positively associated with serum GGT. We demonstrated that pre-therapeutic serum GGT was an independent prognosticator in men with mCRPC receiving docetaxel therapy, and that overexpression of GGT in cancer cells might be responsible for the elevation of serum GGT.

Abstract

Background: Reports on the prognostic significance of serum γ-glutamyltransferase (GGT) in men with metastatic castration-resistant prostate cancer (mCRPC) are limited. In addition, GGT expression status in cancer tissues has not been well characterized regardless of cancer types. Methods: This retrospective study included 107 consecutive men with mCRPC receiving docetaxel therapy. The primary endpoints were associations of serum GGT with overall survival (OS) and prostate-specific antigen (PSA) response. The secondary endpoint was an association of serum GGT with progression-free survival (PFS). Additionally, GGT expression status was immunohistochemically semi-quantified using tissue microarrays. Results: A total of 67 (63%) men died during follow-up periods (median 22.5 months for survivors). On multivariable analysis, high Log GGT was independently associated with adverse OS (HR 1.49, p = 0.006) as were low hemoglobin (HR 0.79, p = 0.002) and high PSA (HR 1.40, p < 0.001). In contrast, serum GGT was not significantly associated with PSA response or PFS. Moreover, incorporation of serum GGT into established prognostic models (i.e., Halabi and Smaletz models) increased their C-indices for predicting OS from 0.772 to 0.787 (p = 0.066) and from 0.777 to 0.785 (p = 0.118), respectively. Furthermore, there was a positive correlation between serum and tissue GGT levels (ρ = 0.53, p = 0.003). Conclusions: Serum GGT may be a prognostic biomarker in men with mCRPC receiving docetaxel therapy. GGT overexpression by prostate cancer cells appears to be responsible for the elevation of GGT in the serum.

Expression Status and Prognostic Significance of Gamma-Glutamyl Transpeptidase Family Genes in Hepatocellular Carcinoma

PURPOSE

Gamma-glutamyl transpeptidase (GGT) family genes play crucial roles in the formation and progression of several solid tumors. However, the expression patterns and the prognostic significance of GGT members in hepatocellular carcinoma (HCC) remain unknown. This study was designed to determine the expression profiles of GGT family members in HCC and validate the prognostic value of serum GGT protein in patients with HCC.

METHOD

We comprehensively searched public resources based on the LIHC dataset to determine the expression patterns, prognostic significance, DNA methylation status, immune infiltration, and biological pathways of GGT family genes in HCC. Subsequently, we validated the prognostic value of serum GGT protein in 85 patients with early-stage HCC subjected to curative hepatectomy from the Renmin Hospital of Wuhan University.

RESULTS

Except for GGT1, other GGT family members (GGT5, GGT6, and GGT7) were found to be differentially expressed in primary HCC samples (N = 371) and normal control tissues (N = 50). Furthermore, a positive relationship was not only observed between GGT1 and GGT5 (Spearman coefficient: 0.24, P = 5.143 × 10-6) but also between GGT5 and GGT6 (Spearman coefficient: 0.38, P = 1.24 × 10-13). The expression of GGT1, GGT5, and GGT7 was correlated with overall survival (OS), and GGT7 was associated with disease-free survival (DFS) in patients with HCC. Negative associations between DNA methylation and expression of mRNA were observed for GGT1 (Spearman coefficient: -0.38, P = 6.24e-14), GGT6 (Spearman coefficient: -0.29, P = 1.23e-8), and GGT7 (Spearman coefficient: -0.34, P=6.7e-11). GGT family genes were well correlated with the infiltration levels of immune cells in HCC, especially CD4+ T cells, macrophages, and dendritic cells. Finally, when validated with clinical data from the Renmin cohort, a high expression of serum GGT protein was identified as a strong prognostic element of unfavorable OS (HR = 3.114, P = 0.025), but not of DFS (HR = 1.198, P = 0.05) in patients with HCC subjected to curative hepatectomy.

CONCLUSION

To our knowledge, this is the first comprehensive analysis of the expression patterns and clinical value of GGT family genes in patients with HCC. Our study laid the foundation for the clinical application of the GGT protein in the survival assessment of patients with HCC.

A de novo strategy to develop NIR precipitating fluorochrome for long-term in situ cell membrane bioimaging

Cell membrane-targeted bioimaging is a prerequisite for studying the roles of membrane-associated biomolecules in various physiological and pathological processes. However, long-term in situ bioimaging on the cell membrane with conventional fluorescent probes leads to diffusion into cells from the membrane surface. Therefore, we herein proposed a de novo strategy to construct an antidiffusion probe by integrating a fluorochrome characterized by strong hydrophobicity and low lipophilicity, with an enzyme substrate to meet this challenge. This precipitating fluorochrome HYPQ was designed by conjugating the traditionally strong hydrophobic solid-state fluorochrome 6-chloro-2-(2-hydroxyphenyl) quinazolin-4(3H)-one (HPQ) with a 2-(2-methyl-4H-chromen-4-ylidene) malononitrile group to obtain closer stacking to lower lipophilicity and elongate emission to the far-red to near-infrared wavelength. As proof-of-concept, the membrane-associated enzyme γ-glutamyltranspeptidase (GGT) was selected as a model enzyme to design the antidiffusion probe HYPQG. Then, benefiting from the precipitating and stable signal properties of HYPQ, in situ imaging of GGT on the membrane was successfully realized. Moreover, after HYPQG was activated by GGT, the fluorescence signal on the cell membrane remained unchanged, with incubation time even extending to 6 h, which is significant for in situ monitoring of enzymatic activity. In vivo testing subsequently showed that the tumor region could be accurately defined by this probe after long-term in situ imaging of tumor-bearing mice. The excellent performance of HYPQ indicates that it may be an ideal alternative for constructing universal antidiffusion fluorescent probes, potentially providing an efficient tool for accurate imaging-guided surgery in the future.

Diagnostic value of gamma-glutamyl transpeptidase to alkaline phosphatase ratio combined with gamma-glutamyl transpeptidase to aspartate aminotransferase ratio and alanine aminotransferase to aspartate aminotransferase ratio in alpha-fetoprotein-negative hepatocellular carcinoma

BACKGROUND

The purpose of the study was to evaluate the diagnostic value of gamma-glutamyl transpeptidase to alkaline phosphatase ratio (GAPR) combined with gamma-glutamyl transpeptidase to aspartate aminotransferase ratio (GAR) and alanine aminotransferase to aspartate aminotransferase ratio (AAR) in alpha-fetoprotein (AFP)-negative hepatocellular carcinoma (HCC).

METHODS

A total of 925 AFP-negative patients, including 235 HCC patients, 213 chronic hepatitis (CH) patients, and 218 liver cirrhosis (LC) patients, as well as 259 healthy controls were enrolled in this study. The differences of laboratory parameters and clinical characteristics were analyzed by Mann-Whitney U or Kruskal-Wallis H-test. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic value of GAPR, GAR, and AAR in AFP-negative HCC (AFP-NHCC) patients.

RESULTS

GAPR, GAR, and AAR were important parameters closely related to AFP-NHCC. The combination of GAPR, GAR, and AAR was most effective in differentiating AFP-NHCC group from control group (AUC = 0.875), AFP-negative CH group (AUC = 0.733), and AFP-negative LC group (AUC = 0.713). GAPR combined with GAR and AAR exhibited a larger AUC than single ratio or pairwise combination for distinguishing AFP-NHCC group with TNMⅠstage, BCLC stage A, and tumor size less than 3 cm. The diagnostic value of GAPR combined with GAR and AAR was higher in AFP-NHCC and was also reflected in the TNM stage, Barcelona Clinic Liver Cancer (BCLC) stage and tumor size.

CONCLUSIONS

GAPR combined with GAR and AAR were effective diagnostic markers of AFP-NHCC, especially in patients with good liver function, early stage or small size.

Enhanced Susceptibility to Breast Cancer in Korean Women With Elevated Serum Gamma-Glutamyltransferase Levels: A Nationwide Population-Based Cohort Study

Background

The incidence of breast cancer has been gradually increasing in Korea. Recently, the elevated level of serum gamma-glutamyltransferase (GGT) has emerged to be associated with the development and progression of some malignancies. This study aimed to determine the effect of serum GGT levels on the risk of developing breast cancer in Korean women.

Methods

We used National Health Insurance Service Health Checkup data to examine the association between serum GGT levels and breast cancer development in Korean women. Women aged 40 years or older who participated in the Korean National Health Screening Examination between January 2009 and December 2009 and who did not develop any cancer within 1-year post examination were included in this analysis (n = 3,109,506). Cox proportional hazard regression analysis was conducted to calculate hazard ratios (HRs) with 95% confidence intervals (CIs).

Results

Overall, an elevated serum GGT level was associated with the increased risk of developing breast cancer; compared to the Q1 group, the Q4 group showed a significantly increased breast cancer risk (HR: 1.120,95% CI: 1.08-1.162). Such a relationship was stronger in post-menopausal women than pre-menopausal women (HR: 1.173, 95% CI: 1.107-1.243; HR: 1.070, 95% CI:1.019-1.124). Women with a high GGT level (Q4) were also at an increased risk of developing carcinoma in situ (CIS) (HR: 1.114, 95% CI: 1.04-1.192). In post-menopausal women, the Q4 group also exhibited higher CIS risk (HR: 1.266, 95% CI: 1.132-1.416). However, no significant difference in the risk of developing CIS was observed between the Q1 and Q4 groups in pre-menopausal women. Further analysis revealed that obese, post-menopausal women with a high GGT level (Q4) were associated with an increased risk of developing breast cancer (HR: 1.214, 95% CI: 1.125-1.31) and CIS (HR: 1.348, 95% CI: 1.159-1.569).

Conclusions

Our study results demonstrate that increased serum GGT level is a risk factor for developing breast cancer. The post-menopausal women group with obesity and elevated serum GGT level showed the highest incidence of breast cancer. Thus, serum GGT concentration could be a novel and potential risk factor for breast cancer. Further validation in different ethnic groups would be warranted.

Prognostic Value of the Albumin-to-γ-glutamyltransferase Ratio for Gallbladder Cancer Patients and Establishing a Nomogram for Overall Survival

Purpose: The albumin-to-γ-glutamyltransferase ratio (AGR), a novel inflammation-related index, has been reported to have prognostic importance in several malignancies but not yet in gallbladder cancer (GBC). This study intended to assess the prognostic value of AGR in GBC and to develop a nomogram based on AGR for predicting overall survival (OS) in GBC patients after surgery.

Methods: Medical records of 140 qualified GBC patients between July 2003 and June 2017 were retrospectively analyzed. The function “surv_cutpoint” in the R package “survminer” was implemented to discover the optimal cut-off value of AGR. A nomogram on the fundamental of Cox model was established in the training cohort and was internally validated using calibration curves, Harrell's concordance index, time-dependent AUC plots and decisive curve analyses.

Results: The optimal AGR cut-off value concerning overall survival was 2.050. Univariate and multivariate analyses demonstrated that AGR (HR=0.354, P=0.004), T stage (HR=3.114, P=0.004), R0 resection (HR=0.448, P=0.003), BMI (HR=0.470, P=0.002) and CA19-9 (HR=1.704, P=0.048) were independent predictors for OS. The nomogram combining these prognostic factors showed considerable prognostic performance in term of consistency, discrimination and net benefit.

Conclusion: AGR has independent prognostic value for OS in GBC patients receiving surgery. A nomogram incorporating AGR, T stage, R0 resection, CA19-9 and BMI achieved enhanced prognostic ability.

Preoperative Serum Gamma-Glutamyltransferase as a Prognostic Biomarker in Patients Undergoing Radical Cystectomy for Bladder Cancer

Background

Serum gamma-glutamyltransferase (GGT) has been reported to be correlated with survival in a variety of malignancies. However, its effect on patients with bladder cancer (BC) treated by radical cystectomy has never been evaluated.

Patients and Methods

We retrospectively evaluated 263 patients who underwent radical surgery in our center. Baseline features, hematologic variables, and follow-up data were obtained. The endpoints included overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). The relationship between GGT and survival were evaluated.

Results

The median follow-up period for all patients was 34.7 (22.9-45.9) months. At the last follow-up, 67 patients died, 51 patients died of cancer, 92 patients experienced disease recurrence. Patients with an elevated serum GGT had a higher rate of pT3-T4 tumors. Patients with a higher preoperative serum GGT had a lower rate of OS, CSS and DFS (P < 0.001 for all). Multivariate analysis identified that preoperative serum GGT was independent predictor of OS (HR: 3.027, 95% CI: 1.716-5.338; P < 0.001), CSS (HR: 2.115, 95% CI: 1.093-4.090; P = 0.026), DFS (HR: 2.584, 95% CI: 1.569-4.255; P < 0.001). Age, diabetes history, pathologic T stage, and lymph node status also were independent predictors of prognosis for BC patients.

Conclusions

Our results indicated that preoperative serum GGT was an independent prognosis predictor for survival of BC patients after radical cystectomy, and can be included in the prognostic models.

A Systematic Review of Serum γ-Glutamyltransferase as a Prognostic Biomarker in Patients with Genitourinary Cancer

γ-Glutamyltransferase (GGT), a membrane-bound enzyme, contributes to the metabolism of glutathione (GSH), which plays a critical physiological role in protecting cells against oxidative stress. GGT has been proposed as a biomarker of carcinogenesis and tumor progression given that GGT activity is important during both the promotion and invasion phases in cancer cells. Moreover, GGT expression is reportedly related to drug-resistance possibly because a wide range of drugs are conjugated with GSH, the availability of which is influenced by GGT activity. While serum GGT activity is commonly used as a quick, inexpensive, yet reliable means of assessing liver function, recent epidemiological studies have shown that it may also be an indicator of an increased risk of prostate cancer development. Moreover, elevated serum GGT is reportedly an adverse prognostic predictor in patients with urologic neoplasms, including renal cell carcinoma, prostate cancer, and urothelial carcinoma, although the background mechanisms have still not been well-characterized. The present review article summarizes the possible role of GGT in cancer cells and focuses on evidence evaluation through a systematic review of the latest literature on the prognostic role of serum GGT in patients with genitourinary cancer.

Impact of Serum γ-Glutamyltransferase on Overall Survival in Patients with Metastatic Renal Cell Carcinoma in the Era of Targeted Therapy

BACKGROUND

γ-Glutamyltransferase (GGT) is a marker of oxidative stress. Elevated serum GGT is linked to poor survival in various malignancies; however, there are no data on metastatic renal cell carcinoma (mRCC). Additionally, GGT expression in cancer tissues remains largely unknown.

OBJECTIVE

The present study was designed to determine the prognostic role of serum GGT in patients with mRCC and the association between systemic and local GGT levels.

PATIENTS AND METHODS

Pretherapeutic serum GGT and other clinicopathological parameters were retrospectively compared with overall survival (OS) in 146 consecutive patients with mRCC receiving tyrosine kinase inhibitor therapy. GGT expression was analyzed in 65 resected specimens using immunohistochemistry.

RESULTS

A total of 82 patients (56%) died during the follow-up period (median 34.9 months). Median OS was 16.0 months and 36.8 months in patients with elevated GGT levels and without elevated GGT, respectively (P < 0.001). On multivariable analysis, elevated serum GGT was an independent adverse prognostic factor (hazard ratio [HR] 4.04, P < 0.001), together with high neutrophils (HR 2.06, P = 0.041), low albumin (HR 2.00, P = 0.006), high lactate dehydrogenase (HR 2.68, P < 0.001), and high De Ritis ratio (HR 1.97, P = 0.004). Preoperative serum GGT levels were 29, 48, and 109 U/l in patients whose renal cancer cells showed negative to weak, moderate, and strong GGT expression, respectively (P = 0.004).

CONCLUSIONS

Elevated serum GGT was an unfavorable prognostic factor in mRCC, and overexpression of GGT in renal cancer cells might be responsible for elevation of serum GGT.

High serum gamma-glutamyl transpeptidase concentration associates with poor postoperative prognosis of patients with hepatitis B virus-associated intrahepatic cholangiocarcinoma

Background

Intrahepatic cholangiocarcinoma (ICC) caused by chronic hepatitis B virus (HBV) infection has become prominent. Prospectively stratifying postoperative risk factors is a challenging task.

Methods

We retrospectively assessed the relationship between serum gamma-glutamyl transpeptidase (GGT) concentration and postoperative outcomes in 107 subjects with HBV-associated ICC. Cox proportionate hazard models and subgroup analyses were used to test the hypothesis with adjustment for potential confounders.

Results

Serum GGT concentration was negatively correlated with postoperative outcomes. For a 1-standard deviation (per-SD) (117 µ/L) increase of serum GGT concentration, the relative risk (RR) for overall survival (OS) and time to recurrence (TTR) were 1.72 [95% confidence interval (CI), 1.37 to 2.16] and 1.53 (95% CI, 1.22 to 1.91), respectively. In addition, the RRs of middle and top tertiles of GGT for death were 1.81 (95% CI, 0.98 to 3.32) and 3.56 (95% CI, 1.97 to 6.42), respectively (P for trend <0.001). Similarly, the RRs for recurrence of the corresponding tertiles were 1.70 (95% CI, 0.93 to 3.10) and 3.27 (95% CI, 1.77 to 6.06), respectively (P for trend =0.002). In our study, the negative correlation between serum GGT levels and OS did not differ significantly between groups stratified by age, sex, HBV DNA level, carbohydrate antigen 19-9 (CA19-9) level and liver resection type (all P for interaction >0.05); however, there was a significant interactive effect of serum GGT and adjuvant chemotherapy on OS (RR =0.64 vs. 1.77, P for interaction =0.04).

Conclusions

High serum GGT concentration is associated with an increased risk of postoperative death and tumor recurrence in patients with HBV-associated ICC. However, this relationship became less significant with the implementation of adjuvant chemotherapy.

The Predictive Value of Pre-therapeutic Serum Gamma-glutamyl transferase in Efficacy and Adverse Reactions to Neoadjuvant Chemotherapy among Breast Cancer Patients

Purpose

Gamma-glutamyl transferase (GGT) has been reported as being involved in tumor progression. Previous studies documented a potential relationship between serum GGT level and survival outcome in several types of human malignancies. However, the association between serum GGT levels and response to neoadjuvant chemotherapy (NAC) has not yet been reported. The present study aimed to evaluate the association between pre-therapeutic serum GGT level and the efficacy, long-term survival, and adverse reactions of NAC and to investigate its role in predicting NAC sensitivity in patients with breast cancer.

Methods

A total of 129 patients were recruited and stratified into 2 groups according to serum GGT level (< 29 U/L and ≥ 29 U/L). The association between pre-therapeutic serum GGT levels and clinicopathological parameters was examined. The correlation between pre-therapeutic serum GGT levels and pathological complete response (pCR) was analyzed using univariate and multivariate logistic regression. Survival analyses of relapse-free survival (RFS) and disease-free survival (DFS) were performed. Pearson's χ² test and multivariate logistic regression model were used to analyze the correlation between pre-therapeutic serum GGT levels and adverse reactions.

Results

Pre-therapeutic serum GGT levels were associated with pCR among breast cancer patients treated with NAC. Multivariate analysis showed that low-level GGT significantly increased pCR rate. Patients in the high-level GGT group had poorer survival than those in the low-level GGT group. Subgroup analysis demonstrated that serum GGT level was potentially related to RFS and DFS in the hormone receptor-positive group. Low levels of GGT are significantly associated with a higher incidence of neutropenia.

Conclusion

Pre-therapeutic serum GGT level is an independent and novel biomarker for predicting the efficiency, prognosis, and adverse reactions to NAC in breast cancer patients. Patients with low pre-therapeutic serum GGT levels are more likely to have higher pCR rates, better RFS and DFS, and higher hematologic toxicity.

Trial Registration

ClinicalTrials.gov Identifier: NCT02199418, NCT02221999

Atorvastatin associated with gamma glutamyl transpeptidase elevation in a hyperlipidemia patient: A case report and literature review

RATIONALE

Atorvastatin is the most common drug used in therapy for cardiovascular diseases. The most common adverse side effects associated with statins are myopathy and hypertransaminasemia. Here, we report a rare case of gamma glutamyl transpeptidase (GGT) elevation induced by atorvastatin.

PATIENT CONCERNS

A 47-year-old male was admitted to our hospital with dyslipidemia, he had been taking pitavastatin 2 mg/day for 2 months. The levels of total cholesterol (265.28 mg/dL) and low-density lipoprotein-cholesterol (LDL) (179.15 mg/dL) were also high.

DIAGNOSIS

Blood lipid test showed mixed dyslipidemia.

INTERVENTION

Atorvastatin 10 mg/day was given to the patient.

OUTCOMES

The patient came back to our hospital for blood tests after 4 weeks. Although no symptoms were detectable, the patient's GGT level was markedly elevated (up to 6-fold over normal level) with less marked increases in alkaline phosphatase (ALP) and alanine aminotransferase (ALT). The serum GGT level returned to normal within 6 weeks of cessation of atorvastatin.

LESSONS

This is a case of GGT elevation without hyperbilirubinemia, hypertransaminasemiam, or serum creatine phosphokinase (CPK) abnormalities despite an atorvastatin regimen. This case highlights GGT elevation caused by atorvastatin, a rare but serious condition. Clinicians should be aware of these possible adverse effects and monitor liver function tests in patients on statin therapy.

Prognostic Significance of Preoperative Gamma-Glutamyltransferase to Alkaline Phosphatase Ratio in Hepatocellular Carcinoma Patients with Curative Liver Resection: A Retrospective Cohort Study

Purpose

Gamma-glutamyltransferase (GGT) and alkaline phosphatase (ALP) were involved in the development and progression of cancers. This study aimed to evaluate the prognostic value of a preoperative GGT:ALP ratio (GAR) in hepatocellular carcinoma (HCC) patients with curative liver resection.

Patients and Methods

A total of 380 HCC patients underwent curative liver resection before December 2017 and from January to December 2018 were included and stratified into training set and validation set, respectively. Prediction accuracy was evaluated by the area under the receiver operating characteristic curve (AUC). Factors determined to be significant for overall survival (OS) and tumor-free survival (TFS) by using Cox regression analysis. The Kaplan–Meier method and Log rank test were utilized for survival analysis.

Results

The AUC of GAR was 0.70 (P < 0.001). An optimal cut-off value of 0.91 yielded a sensitivity of 78.1% and a specificity of 60.4% for GAR (P < 0.001), which stratified the HCC patients into high-risk (>0.91) and low-risk (≤ 0.91) groups. Time-dependent ROC revealed that the AUCs for 1-, 3-, and 5-year OS predictions for GAR were 0.60, 0.69 and 0.62, respectively. In addition, GAR was identified as an independent risk factor for OS and TFS both in training and validation cohort by univariate and multivariate Cox regression analysis, as well as a good prognostic indicator for patients with Barcelona Clinic Liver Cancer stage C or without vascular invasion. Notably, the AUC of the GAR for survival was better than several potential prognostic indices (P < 0.05).

Conclusion

We identified the GAR as a prognostic indicator in two independent cohorts of HCC patients with curative liver resection. The patients with decreased GAR score were significantly associated with better OS and TFS.

Cell-Membrane-Localizing, Two-Photon Probe for Ratiometric Imaging of γ-Glutamyl Transpeptidase in Cancerous Cells and Tissues

γ-Glutamyl transpeptidase (GGT), a cell surface-bound protease, is associated with various diseases including cancer. The detection of the enzyme activity is an important subject, leading to about 40 activatable fluorescent probes so far. All of them, however, lack the membrane-localizing ability, raising a reliability issue in the quantitative analysis. Disclosed is the first fluorescent probe that senses the cell surface-bound enzyme, which, furthermore, is capable of ratiometric as well as two-photon imaging with desirable features. Ratiometric imaging of cancer cell lines reveals a 6.4-8.4-fold higher GGT levels than those in normal cell lines. A comparison of the enzyme activity in organ tissues of normal and tumor xenograft mice reveals notably different levels of enzyme activity depending on the kind of tissue. Normal tissues exhibited comparable levels of enzyme activity, except the kidney that has significantly higher GGT activity (2.7-4.0-fold) than the other organs. Compared with the normal tissues, considerably higher enzyme activity was observed in the tumor tissues of the thigh (4.0-fold), colon (2.5-fold), lung (3.6-fold), and liver (2.1-fold), but essentially no enhanced activity in the tumor tissues of the spleen, stomach, and pancreas and a comparable level in both the tumor and normal kidney tissues were observed. The probe offers practical means for studying GGT-associated biology in cells and tissues by one- as well as two-photon ratiometric imaging.

Serum Exosomal Gamma-Glutamyltransferase Activity Increased in Patients with Renal Cell Carcinoma with Advanced Clinicopathological Features

BACKGROUND

There has been no clinically useful diagnostic or prognostic biomarker for renal cell carcinoma (RCC). Serum γ-glutamyltransferase (GGT) activity has been reported to be a prognostic marker for several types of cancer including RCC. Exosomes or small extracellular vesicles present in body fluids have potential as a biomarker. We have recently demonstrated that GGT activity on exosomes isolated from serum is useful for the differential diagnosis of prostate cancer and benign prostate hyperplasia. In this study, we aimed to examine if serum exosomal GGT activity could be a marker for RCC.

METHODS

We examined GGT1 expression and GGT activity in cell lysates and exosomes from culture medium of HK-2 proximal tubule epithelial and RCC cell lines. GGT activity was measured using a fluorescent probe for GGT, γ-glutamyl hydroxymethyl rhodamine green. Serum and serum exosomal GGT activities were measured in patients with RCC. GGT1 expression in RCC tissues was evaluated by immunohistochemical staining.

RESULTS

GGT1 levels in exosomes from KMRC-1, OS-RC-2 and 786-O cells were elevated compared with those from HK-2 cells. In exosomes, GGT1 expression correlated with GGT activity determined using a fluorescent probe for GGT. In RCC patients, serum exosomal GGT activity was elevated in those with advanced stages (III/IV vs. I/II, p = 0.037) and those with microvascular invasion (with vs. without, p = 0.034). Immunohistochemical analysis showed that membranous GGT1 expression was increased in RCC with microvascular invasion. Notably, preoperative serum exosomal GGT activity could predict the likelihood of having microvascular invasion diagnosed by pathological examination of surgically resected specimens.

CONCLUSIONS

Our results suggest that serum exosomal GGT activity could be a clinically useful marker for advanced clinicopathological features of RCC patients, and its combined use with conventional diagnostic modalities may improve the diagnosis and treatment of patients.

Novel Value of Preoperative Gamma-Glutamyltransferase Levels in the Prognosis of AFP-Negative Hepatocellular Carcinoma

Background

Gamma-glutamyltransferase (GGT) is involved in tumor development and progression, but its prognostic value in α-fetoprotein- (AFP-) negative (AFP < 25 ng/mL) hepatocellular carcinoma (HCC) patients remains unknown.

Methods

A large cohort of 678 patients with AFP-negative HCC following curative resection who had complete data were enrolled in this study. The optimal cutoff value for the preoperative level of GGT was determined by the X-tile program. Independent prognostic factors for overall survival (OS) and disease-free survival (DFS) were also identified.

Results

The optimal cutoff values for the preoperative levels of GGT were 37.2 U/L and 102.8 U/L, which were used to divide all patients into three subgroups (group 1, GGT < 37.2 U/L (n = 211, 31.1%); group 2, GGT ≥ 37.2 and <102.8 U/L (n = 320, 47.2%); group 3, GGT ≥ 102.8 U/L (n = 147, 21.7%)), with distinct OS times (58.5 vs. 53.5 vs. 44.4 months, P < 0.001) and DFS times (47.9 vs. 40.3 vs. 30.1 months, P < 0.001). Elevated preoperative GGT levels were associated with an unfavorable tumor burden (larger tumor size, multiple tumors, and microvascular invasion) and were selected as independent predictors of a worse OS (group 2 vs. group 1, HR: 1.73 (1.13-2.65), P = 0.011; group 3 vs. group 1, HR: 3.28 (2.10-5.13), P < 0.001) and DFS (group 2 vs. group 1, HR: 1.52 (1.13-2.05), P = 0.006; group 3 vs. group 1, HR: 2.11 (1.49-2.98), P < 0.001) in multivariable analysis.

Conclusions

Elevated preoperative GGT levels are associated with an unfavorable tumor burden and serve as an independent prognostic marker for worse outcomes in AFP-negative HCC patients following resection.

Cancer-associated fibroblasts-derived gamma-glutamyltransferase 5 promotes tumor growth and drug resistance in lung adenocarcinoma

Gamma-glutamyltransferase 5 (GGT5) is a member of the gamma-glutamyl transpeptidase gene family with the capacity of cleaving the gamma-glutamyl moiety of glutathione, but its role in cancer progression has never been revealed. In this study, we found that gene GGT5 was highly expressed in cancer-associated fibroblasts (CAFs) in lung adenocarcinoma, predicting the unfavorable survival of patients with lung adenocarcinoma. Cell growth, foci formation and spheres formation analyses showed that cancer cell proliferation was attenuated under treatment with the conditioned media from GGT5-silenced CAFs. Moreover, high expression of GGT5 in CAFs enhanced the drug resistance of cancer cells by increasing intracellular glutathione and reducing the intracellular reactive oxygen species in cancer cells. In mouse xenograft model, we proved that targeting GGT5 with a small-molecule inhibitor GGsTop could inhibit tumor growth and increase the chemosensitivity of cancer cells. Taken together, our study illuminates that high level of GGT5 in CAFs contributes to cancer cell survival and drug resistance, indicating that GGT5 may be a promising therapeutic target in lung adenocarcinoma.

Predictive clinical factors of chronic peripheral neuropathy induced by oxaliplatin

PURPOSE

We aimed to identify potential clinical parameters that can be easily obtained by a pre-treatment clinicopathological evaluation and whole blood test to estimate the development of oxaliplatin-induced peripheral neuropathy (OIPN).

METHODS

This study was conducted retrospectively. For the FOLFOX regimen, patients received oxaliplatin, 85 mg/m², every 2 weeks for 12 courses, and with the XELOX regimen, oxaliplatin was 130 mg/m², every 3 weeks for 6-8 courses. The incidence and degree of neuropathy (NCI-CTCAE v.3) were recorded.

RESULTS

A total of 186 patients were included in the study. There were 108 (58%) patients in the grade 0-1 (G0-G1) neuropathy group (mean age 50.5 ± 11.5; 63% men), and 78 (42%) patients in the grade 2-3 (G2-G3) neuropathy group (mean age 58.0 ± 10.8; 46.2% men). The relationship between G2-G3 OIPN development and age (p < 0.001), gender (p = 0.02), and ECOG performance status (p = 0.007) was statistically significant. In the G2-G3 neuropathy group, serum gamma-glutamyl transferase (GGT) (p < 0.001) and glucose (p = 0.007) levels were higher, whereas vitamin D (p < 0.001), hemoglobin (Hgb) (p < 0.001), serum albumin (p = 0.001), and serum magnesium (p = 0.035) levels were lower compared with the G0-G1 neuropathy group. G2-G3 neuropathy was observed in 88% of patients with mucinous carcinoma pathologic type (p < 0.001).

CONCLUSION

This study demonstrated that age, histopathologic type, albumin, GGT, glucose, vitamin D, and Hgb levels were the effective factors in prediction of the development of OIPN. In addition, GGT, vitamin D, and Hgb levels were the most effective factor to predict development of OIPN.

The mercapturic acid pathway

The mercapturic acid pathway is a major route for the biotransformation of xenobiotic and endobiotic electrophilic compounds and their metabolites. Mercapturic acids (N-acetyl-l-cysteine S-conjugates) are formed by the sequential action of the glutathione transferases, γ-glutamyltransferases, dipeptidases, and cysteine S-conjugate N-acetyltransferase to yield glutathione S-conjugates, l-cysteinylglycine S-conjugates, l-cysteine S-conjugates, and mercapturic acids; these metabolites constitute a "mercapturomic" profile. Aminoacylases catalyze the hydrolysis of mercapturic acids to form cysteine S-conjugates. Several renal transport systems facilitate the urinary elimination of mercapturic acids; urinary mercapturic acids may serve as biomarkers for exposure to chemicals. Although mercapturic acid formation and elimination is a detoxication reaction, l-cysteine S-conjugates may undergo bioactivation by cysteine S-conjugate β-lyase. Moreover, some l-cysteine S-conjugates, particularly l-cysteinyl-leukotrienes, exert significant pathophysiological effects. Finally, some enzymes of the mercapturic acid pathway are described as the so-called "moonlighting proteins," catalytic proteins that exert multiple biochemical or biophysical functions apart from catalysis.

Biomimetic polymeric nanoparticle-based photodynamic immunotherapy and protection against tumor rechallenge

In this study, we sought to design a bionanomaterial that could exert anticancer effects against primary tumors and protect against rechallenged tumorsviaphotodynamic immunotherapy.

Prognostic Significance of Serum Uric Acid and Gamma-Glutamyltransferase in Patients with Advanced Gastric Cancer

PURPOSE

In this study, we aim to evaluate the prognostic role of serum uric acid and gamma-glutamyltransferase in advanced gastric cancer patients.

METHODS

A total of 180 patients pathologically diagnosed with advanced gastric cancer were included in this retrospective study. We used time-dependent receiver operating characteristic (ROC) curves to identify the optimal cut-off value of serum uric acid (UA) and gamma-glutamyltransferase (GGT). Survival analysis was performed using the Kaplan-Meier method and log-rank test, and multivariate Cox regression analyses were applied. A nomogram was formulated, and the calibration and discrimination of the nomogram were determined by calibration curve and concordance index (C-index). We validated the results using bootstrap resampling and a separate study on 60 patients collected from 2015 to 2017 using the same criteria in other medical center.

RESULTS

Both higher serum uric acid (>228 μmol/L) and higher gamma-glutamyltransferase (>14 U/L) had worse OS and PFS. Univariate analysis indicated that serum uric acid (UA) (p < 0.001 and p < 0.001) and gamma-glutamyltransferase (GGT) (p < 0.001 and p = 0.044) were significantly related to overall survival (OS) and progression-free survival (PFS), respectively. Multivariate analysis revealed serum uric acid (UA) and gamma-glutamyltransferase (GGT) were independent prognostic factors for OS (p = 0.012, p = 0.001). The optimal agreement between actual observation and nomogram prediction was shown by calibration curves. The C-indexes of the nomogram for predicting OS and PFS were 0.748 (95% CI: 0.70-0.79) and 0.728 (95% CI: 0.6741-0.7819), respectively. The results were confirmed in the validation cohort.

CONCLUSION

We observed that both serum UA and GGT were poor prognostic factors in patients with advanced gastric cancer. And we also formulated and validated a nomogram which can predict individual survival for advanced gastric cancer patients.

Serum gamma-glutamyltransferase and the overall survival of metastatic pancreatic cancer

Background

Accumulating evidence suggests that Gamma-glutamyltransferase (GGT) may be involved in cancer occurrence and progression. However, the prognostic role of serum GGT in pancreatic cancer (PC) survival lacks adequate evaluation. In this study, we aimed to analyze the association between serum GGT measured at diagnosis and overall survival (OS) in patients with metastatic PC.

Methods

We identified 320 patients with histopathologically confirmed metastatic pancreatic ductal adenocarcinoma (PDAC) diagnosed during 2015 and 2016 at a specialized cancer hospital in southwestern China. Univariate and multivariate Cox proportional-hazards models were used to determine associations between serum GGT and OS in metastatic PDAC.

Results

Controlled for possible confounding factors, serum GGT was significantly associated with OS: serum GGT > 48 U/L yielded a hazard ratio of 1.53 (95% CI: 1.19–1.97) for mortality risk. A significant dose-response association between serum GGT and OS was also observed. Subgroup analysis showed a possible interaction between GGT and blood glucose level.

Conclusion

Serum GGT could be a potential indicator of survival in metastatic PDAC patients. Underlying mechanisms for this association should be investigated.

An Activatable Chemiluminescent Probe for Sensitive Detection of γ-Glutamyl Transpeptidase Activity in Vivo

Activatable chemiluminescent probes that show enhanced chemiluminescence upon interaction with a molecular target of interest have offered promising tools for sensing and bioimaging in terms of low background, high sensitivity, and improved penetration depth in biological tissues. Here, we reported a γ-glutamyl transpeptidase (GGT) activatable chemiluminescent probe for real-time detection of GGT activity in vitro and in living mice. The probe was designed by caging an electron-withdrawing acrylic group-substituted Schaap's phenoxy-dioxetane with a GGT-recognitive substrate (γ-Glu) and a self-immolative linker (p-aminobenzyl alcohol), which was initially chemiluminescence off. Upon interaction with GGT, strong chemiluminescence with a more than 800-fold turn-on ratio could be achieved in aqueous solution, allowing to specifically detect GGT activity with ultrahigh signal-to-background ratio and sensitivity in vitro and in live cells. We demonstrated that the probe was reliable to quantify the GGT in serum, permitting to accurately report the elevated levels of GGT in lipopolysaccharide-treated mouse serum. Moreover, through real-time chemiluminescence imaging of GGT activity, the designed probe was feasible to detect GGT-positive tumors in living mice after intravenous systemic administration. This study demonstrates the high potential of GGT-activatable chemiluminescent probe for serum assays and molecular imaging, which might find wide applications in diagnosis of GGT-related diseases.

Combined preoperative albumin-bilirubin (ALBI) and serum γ-glutamyl transpeptidase (GGT) predicts the outcome of hepatocellular carcinoma patients following hepatic resection

Background: Liver function is an important prognostic factor for patients with hepatocellular carcinoma. The purpose of this study was to develop and validate a nomogram integrating the albumin-bilirubin (ALBI) and serum γ-glutamyl transpeptidase (GGT) level to predict postoperative overall survival (OS) and disease-free survival (DFS) of hepatocellular carcinoma (HCC).

Methods: The effect of combined of ALBI and GGT on HCC prognosis was investigated using univariate and multivariate Cox analyses. The nomogram for OS and DFS were developed, respectively, and their predictive ability was compared with other conventional staging systems, including the American Joint Commission on Cancer (AJCC), Barcelona Clinic Liver Cancer (BCLC) and the Cancer of the Liver Italian Program (CLIP).

Results: Combined ALBI and GGT was highly associated with OS (P<0.001) and DFS (P<0.001) of HCC patients treated with hepatic resection. In addition, the C-index of the OS (0.706±0.034) or DFS (0.674±0.032) nomogram in the training cohort was larger than AJCC, BCLC and CLIP. The Akaike information criterion (AICs) of the OS (2178.405) or DFS (2961.018) nomogram in the training cohort was smaller than above staging systems. The results suggested that the OS or DFS nomogram was the most powerful model to predict HCC prognosis. The similar trend was observed in the validation cohort.

Conclusion: The novel nomogram integrating ALBI and GGT was highly associated with OS and DFS of postoperative HCC patients.

A novel triarylboron based ratiometric fluorescent probe for in vivo targeting and specific imaging of cancer cells expressing abnormal concentration of GGT

Abnormal expression of γ-glutamyltranspeptidase (GGT) in living organisms is closely associated with tumorigenesis. However, few reported fluorescence probes can specifically respond to abnormal concentration of GGT. Here, by functionalizing triarylboron moiety with three GGT-specific substrate (GSH) units, a novel fluorescence probe, TAB-3-GSH, was developed for detecting GGT. The results showed that TAB-3-GSH selectively responds to abnormally high levels of GGT (100-1000 U/L) rather than to normal GGT levels (<100 U/L) with ratiometric readout, since the amide linkage can be further hydrolyzed under high GGT levels. TAB-3-GSH was also capable of differentiating GGT-overexpressing ovarian cancer cells from normal cells, because of an improvement in the probe's cell membrane permeability upon reaction with GGT. Moreover, the probe could achieve selective imaging of SKOV-3 tumor site in xenograft mice model. Thus, TAB-3-GSH is a promising probe for tumor targeting in vivo.

Point-of-care Ratiometric Fluorescence Imaging of Tissue for the Diagnosis of Ovarian Cancer

During a minimally invasive tumor resection procedure, it is still a challenge to rapidly and accurately trace tiny malignant tumors in real time. Fluorescent molecular imaging is considered an efficient method of localizing tumors during surgery due to its high sensitivity and biosafety. On the basis of the fact that γ-glutamyltranspeptidase (GGT) is overexpressed in ovarian cancer, we herein designed a highly sensitive ratiometric fluorescent GGT-responsive probe Py-GSH for rapid tumor detection. Methods: The GGT response probe (Py-GSH) was constructed by using GSH group as a response group and pyrionin B as a fluorescent reporter. Py-GSH was characterized for photophysical properties, response speed and selectivity of GGT and response mechanism. The anti-interference ability of ratiometric probe Py-GSH to probe concentration and excitation power was evaluated both in vitro and in tissue. The biocompatibility and toxicity of the ratiometric probe was examined using cytoxicity test. The GGT levels in different lines of cells were determined by ratiometric fluorescence imaging and cytometry analysis. Results: The obtained probe capable to rapidly monitored GGT activity in aqueous solution with 170-fold ratio change. By ratiometric fluorescence imaging, the probe Py-GSH was also successfully used to detect high GGT activity in solid tumor tissues and small peritoneal metastatic tumors (~1 mm in diameter) in a mouse model. In particular, this probe was further used to determine whether the tissue margin following clinical ovarian cancer surgery contained tumor. Conclusion: In combination of ratiometric fluorescence probes with imaging instrument, a point-of-care imaging method was developed and may be used for surgical navigation and rapid diagnosis of tumor tissue during clinical tumor resection.

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.

Gamma-Glutamyltransferase 1 Promotes Clear Cell Renal Cell Carcinoma Initiation and Progression

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer. While the localized form of this disease can be treated surgically, advanced and metastatic stages are resistant to chemotherapies. Although more innovative treatments, such as targeted or immune-based therapies, exist, the need for new therapeutic options remains. ccRCC presents unique metabolic signatures and multiple studies have reported a significant increase in levels of reduced glutathione (GSH) and its precursors in ccRCC tumor samples compared with normal kidney tissues. These observations led us to investigate the effects of blocking the GSH pathway, particularly the gamma-glutamyltransferase 1 (GGT1) enzyme, in multiple ccRCC cell lines. In this study, we provide in vitro and in vivo evidence that GGT1/GSH pathway inhibition impacts ccRCC cell growth, through increased cell-cycle arrest. Of note, GGT1 inhibition also impairs ccRCC cell migration. Finally, pharmacologic GSH pathway inhibition decreases ccRCC cell proliferation and increases sensitivity to standard chemotherapy. Our results suggest that GGT1/GSH pathway inhibition represents a new strategy to overcome ccRCC chemoresistance. IMPLICATIONS: GGT1/GSH pathway inhibition represents a promising therapeutic strategy to overcome chemoresistance and inhibit progression of ccRCC tumors.

Preoperative D-dimer and Gamma-Glutamyltranspeptidase Predict Major Complications and Survival in Colorectal Liver Metastases Patients After Resection

OBJECTIVES: To investigate the predictive value of the pre-operative D-dimer and gamma-glutamyltranspeptidase (GGT) for the prognosis in colorectal liver metastases (CRLM) patients after hepatic resection. METHODS: Two hundred and ninety-two patients between December 2008 and December 2016 and 101 patients at our center from January 2017 to December 2018 were selected as a training set and validation set, respectively. The combination of the pre-operative D-dimer and GGT status (CPDG score) was scored as follows: elevated D-dimer levels with elevated GGT levels was allocated a score of 2, decreased D-dimer levels with decreased GGT levels was allocated a score of 0, and all other combinations were allocated a score of 1. In the training set, a logistic regression was applied to explore potential predictors of major postoperative complications. A Cox proportional hazards analysis was used to analyze survival. We further verified our findings in the validation set. RESULTS: Major complications occurred in 43 (14.7%) and 25 (24.8%) patients in the training set and validation set, respectively. In the training set, multivariate analysis showed that elevated GGT levels and elevated D-dimer levels independently predicted major complications respectively. In the multivariate analyses, elevated pre-operative D-dimer levels remained independently associated with decreased overall survival (OS) (hazard ratio [HR] = 1.751, 95% confidence interval [CI]: 1.139-2.691, P = .01). The CPDG score was an independent prognostic factor for major complications and OS in the multivariate analyses. The predictive ability of the CPDG score was higher than either factor alone. A Kaplan-Meier survival analysis showed that compared with patients with CPDG score = 1 or CPDG score = 0, patients with a CPDG score = 2 had worsened OS. Furthermore, for OS comparisons, the differences between any two groups were significant. In the validation set, elevated GGT and D-dimer were also suggested to predict worse progression-free survival (PFS) and to be independently associated with major complications. CONCLUSIONS: The pre-operative D-dimer levels, GGT levels and CPDG score are reliable biomarkers to predict post-operative major complications or survival in CRLM patients after hepatic resection, which make it useful for CRLM patients in guiding surveillance approaches and prognosis assessments.

Prognostic significance of gamma-glutamyl transferase in patients with metastatic non-small cell lung cancer

BACKGROUND

The prognostic significance of serum gamma-glutamyl transferase (GGT) level at diagnosis in patients with metastatic non-small lung cancer (NSCLC) is not clear. We aimed to assess the relationship between serum GGT level and overall survival (OS) and progression-free survival (PFS) in this patient population.

METHODS

Data of patients with metastatic NSCLC who were admitted to the medical oncology clinic of our hospital during April 2013-December 2017 were retrospectively analyzed. Patients were divided into two groups based on GGT levels, normal and high (as defined by normal reference levels), and then compared.

RESULTS

Significant differences between the high and normal GGT level groups were found regarding female sex, Eastern Cooperative Oncology Group performance score, weight loss at the time of diagnosis, and lactate dehydrogenase level (p < 0.05). The high GGT group had a shorter median OS (11.5 vs. 3.4 months, p < 0.001) and PFS (7.8 vs. 3.0 months, p = 0.001). High GGT level is an independent risk factor for OS (hazard ratio [HR] 2.270; 95% confidence interval [CI], 1.398-3.686; p < 0.001) and PFS (HR 2.489; 95% CI, 1.323-4.684; p = 0.005).

CONCLUSIONS

High serum GGT level is an independent prognostic factor for OS and PFS in metastatic NSCLC patients.

Prognostic significance of serum γ-glutamyltransferase in patients with advanced urothelial carcinoma

OBJECTIVES

Serum γ-glutamyltransferase (GGT) is reportedly associated with prognosis in patients with various malignancies. However, the prognostic role of GGT is unknown among patients with advanced urothelial carcinoma (aUC). This study was designed to examine the prognostic role of serum GGT in patients with aUC.

MATERIALS AND METHODS

Charts of 125 consecutive aUC patients (inoperable cT4 and/or metastasis to lymph nodes/distant organs) managed at a single cancer center between 2004 and 2016 were retrospectively reviewed. Variables collected included age, sex, body mass index, Karnofsky performance status, primary site, clinical tumor stage, lymph node/visceral metastasis, hepatic comorbidities, the presence of curative treatment before the diagnosis of aUC, white blood cell count, neutrophil-to-lymphocyte ratio, hemoglobin, albumin, lactate dehydrogenase, alkaline phosphatase, GGT, C-reactive protein, and treatments given after the diagnosis of aUC. Associations of variables with overall survival (OS) were analyzed using the Cox proportional hazard model.

RESULTS

Serum GGT was elevated (≥60 U/l) at the diagnosis of aUC in 16 patients (13%). During follow-up period (median 12.1 months), 101 patients died (2-year OS rate, 32%). Patients with elevated GGT at the diagnosis of aUC had a significantly poorer prognosis than those with normal GGT with respective 2-year OS rates of 0% and 37% (P < 0.001). On multivariate analysis, elevated GGT was a significant and independent risk factor for shorter OS (hazard ratio, HR = 2.97; P < 0.001) as were poorer Karnofsky performance status (HR = 3.47; P < 0.001), elevated lactate dehydrogenase (HR = 1.86; P = 0.033), advanced age (HR = 1.82; P = 0.013), elevated neutrophil-to-lymphocyte ratio (HR = 1.80; P = 0.015), elevated C-reactive protein (HR = 1.73; P = 0.018), the absence of systemic chemotherapy (HR = 1.71; P = 0.035), and primary site of upper urinary tract (HR = 1.71; P = 0.014) in descending order by HR. The prognostic significance of elevated GGT was also observed in a subset of 101 patients who had been diagnosed with aUC at their first presentation.

CONCLUSION

The present study for the first time demonstrated that elevated serum GGT was an independent adverse prognostic factor in aUC patients.