Identification of glutathione S-transferase omega 1 (GSTO1) protein as a novel tumor-associated antigen and its autoantibody in human esophageal squamous cell carcinoma

Ethacrynic Acid: A Promising Candidate for Drug Repurposing as an Anticancer Agent

Ethacrynic acid (ECA) is a diuretic that inhibits Na-K-2Cl cotransporter (NKCC2) present in the thick ascending loop of Henle and muculo dens and is clinically used for the treatment of edema caused by excessive body fluid. However, its clinical use is limited due to its low bioavailability and side effects, such as liver damage and hearing loss at high doses. Despite this, ECA has recently emerged as a potential anticancer agent through the approach of drug repositioning, with a novel mechanism of action. ECA has been shown to regulate cancer hallmark processes such as proliferation, apoptosis, migration and invasion, angiogenesis, inflammation, energy metabolism, and the increase of inhibitory growth factors through various mechanisms. Additionally, ECA has been used as a scaffold for synthesizing a new material, and various derivatives have been synthesized. This review explores the potential of ECA and its derivatives as anticancer agents, both alone and in combination with adjuvants, by examining their effects on ten hallmarks of cancer and neuronal contribution to cancer. Furthermore, we investigated the trend of synthesis research of a series of ECA derivatives to improve the bioavailability of ECA. This review highlights the importance of ECA research and its potential to provide a cost-effective alternative to new drug discovery and development for cancer treatment.

The Upregulation of GSTO2 is Associated with Colon Cancer Progression and a Poor Prognosis

Colorectal cancer is the second-leading cause of cancer-related mortality in the United States. Glutathione S-transferase can affect the development of cancer. Glutathione S-transferase omega 2, a member of the GST family, plays an important role in many tumors. However, the role of Glutathione S-transferase omega 2 in the development of colon cancer remains unclear. Herein, our study aimed to investigate the exact role of Glutathione S-transferase omega 2 in colon cancer. We used RNA sequencing data from The Cancer Genome Atlas and the Genotype-Tissue Expression database to analyze Glutathione S-transferase omega 2 expressions. Then, we explore the protein information of Glutathione S-transferase omega 2 in the Human Protein Atlas, GeneCards, and String database. In addition, western blot and immunohistochemistry were performed to evaluate the protein levels of Glutathione S-transferase omega 2 in colon cancer tissues. We acquire data from the Gene Expression Omnibus and The Cancer Genome Atlas databases. Also, we performed relevant prognostic analyses of these data. In addition, we performed a statistical analysis of the clinical data from The Cancer Genome Atlas database and the expression level of Glutathione S-transferase omega 2. Then, we performed Cox regression analysis and found independent risk factors for prognosis in patients with colon cancer. The Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses were used to explore the potential biological functions of Glutathione S-transferase omega 2. The infiltration of colon cancer-immune cells was evaluated by the CIBERSORT method. RNA silencing was performed using siRNA constructs in HCT-116 and HT-29 cell lines. Cell Counting Kit-8 and EdU assays were performed to determine cell proliferation. Transwell experiments and scratch tests were used to determine cell migration. As for the mRNA and protein expression levels of cells, we used quantitative real-time PCR and western blot to detect them. Our research shows that Glutathione S-transferase omega 2 is overexpressed in colon cancer patients, and this overexpression is associated with a poor prognosis. The high expression of Glutathione S-transferase omega 2 is significantly correlated stage with stage, M, and N classification progression in colon cancer by statistical analysis. Univariate and multivariate Cox regression analyses showed that Glutathione S-transferase omega 2 was an independent risk factor for poor prognosis in colon cancer. In addition, we also found that Glutathione S-transferase omega 2 expression levels can affect the immune microenvironment of colon cancer cells. Gene silencing of Glutathione S-transferase omega 2 in HT-29 and HCT-116 cells significantly inhibited tumor growth and migration. In summary, we found that Glutathione S-transferase omega 2 can be used as a molecular indicator of colon cancer prognosis. In vitro, gene silencing of Glutathione S-transferase omega 2 inhibited colon cancer cells' growth and migration.

Western blotting: a powerful staple in scientific and biomedical research

Western blotting (WB), also known as immunoblotting, is a well-known molecular biology method that biologists often use to investigate many features of the protein, ranging from basic protein analysis to disease detection. WB is simple, unique, rapid, widely used routine tool with easy interpretation and definite results. It is being used in various fields of science, research and development, diagnostic labs and hospitals. The principle of WB is to accomplish the separation of proteins based on molecular weight and charge. This review addresses in detail the individual steps involved in the WB technique, its troubleshooting, internal loading controls, total protein staining and its diverse applications in scientific research and clinical settings, along with its future perspectives.

Anti-glutathione S-transferase omega 1-1 (GSTO1-1) antibodies are increased during acute and chronic inflammation in humans

Glutathione S-transferase omega-1 (GSTO1-1) is a cytosolic enzyme involved in the modulation of critical inflammatory pathways as well as in cancer progression. Auto-antibodies against GSTO1-1 were detected in the serum of patients with esophageal squamous cell carcinoma and were proposed as potential biomarkers in the early detection of the disease. Our findings show that anti-GSTO1-1 antibodies can be found in a variety of inflammatory diseases, including autoimmune rheumatoid arthritis, infectious SARS-CoV-2, and trichinellosis. Our findings strongly suggest that anti-GSTO1-1 antibodies may be a marker of tissue damage/inflammation rather than a specific tumor-associated biomarker.

Tumor-associated antigens and their antibodies in the screening, diagnosis, and monitoring of esophageal cancers

Despite the advances in the treatment and management, esophageal cancers continue to carry a dismal prognosis with an overall 5-year survival rate ranging from 15 to 25%. Delayed onset of symptoms and lack of effective screening methods and guidelines for diagnosis of the early disease contribute to the high mortality rate of esophageal cancers. Detection of esophageal cancer at their early stage is really a challenge for physicians including primary care physicians, gastroenterologists and oncologists. Although imaging, endoscopy and biopsy have been proved to be useful diagnostic tools for esophageal cancers, their diagnostic accuracy is unsatisfactory. In addition, expensive costs, invasiveness and special training operator have limited the clinical application of these tools. Recently, tumor-associated antigens (TAAs) and their antibodies have been reported to be potential markers in esophageal cancer screening, diagnosis, monitoring and prognostication. Because TAAs and their antibodies have the advantages of inexpensive cost, noninvasiveness and easy access, they have attracted much attention as an affordable option for early esophageal cancer diagnosis. In this review, we summarized the advances in TAAs and their antibodies in esophageal cancer screening, diagnosis, monitoring and prognostication.

Deletion of Glutathione S-Transferase Omega 1 Activates Type I Interferon Genes and Downregulates Tissue Factor

GST omega 1 (GSTO1) is an atypical GST isoform that is overexpressed in several cancers and has been implicated in drug resistance. Currently, no small-molecule drug targeting GSTO1 is under clinical development. Here we have validated GSTO1 as an impactful target in oncology. Transcriptional profiling coupled with proteomics uncovered novel pharmacodynamic markers and cellular pathways regulated by GSTO1. CRISPR/Cas9 GSTO1 knockout (KO) cell lines failed to form tumors or displayed growth delay in vivo; they also formed smaller 3D spheroids in vitro. Multiomics analysis in GSTO1 KO cells found a strong positive correlation with cell adhesion molecules and IFN response pathways and a strong negative correlation with Myc transcriptional signature. In addition, several clinically used drugs showed significant synthetic lethality with loss or inhibition of GSTO1. Transcription and protein expression of tissue factor (gene name, F3) were downregulated in response to GSTO1 KO. F3 is associated with poor patient survival and promotion of tumor progression in multiple cancers and is a known risk factor for metastasis. Transcription of F3 was regulated by IL1β, whose secretion decreased upon inhibition of GSTO1, suggesting that IL1β links GSTO1 expression and F3 transcription. In summary, our results implicate GSTO1 as a potential therapeutic target in cancer and offer new mechanistic insights into its significant role in cancer progression. SIGNIFICANCE: These findings validate GSTO1 as a therapeutic target in cancer and implicate GSTO1 in the modulation of tumor growth, immune responses, and expression of F3.

Identification of a Blood-Based Protein Biomarker Panel for Lung Cancer Detection

Lung cancer is the deadliest cancer worldwide, mainly due to its advanced stage at the time of diagnosis. A non-invasive method for its early detection remains mandatory to improve patients’ survival. Plasma levels of 351 proteins were quantified by Liquid Chromatography-Parallel Reaction Monitoring (LC-PRM)-based mass spectrometry in 128 lung cancer patients and 93 healthy donors. Bootstrap sampling and least absolute shrinkage and selection operator (LASSO) penalization were used to find the best protein combination for outcome prediction. The PanelomiX platform was used to select the optimal biomarker thresholds. The panel was validated in 48 patients and 49 healthy volunteers. A 6-protein panel clearly distinguished lung cancer from healthy individuals. The panel displayed excellent performance: area under the receiver operating characteristic curve (AUC) = 0.999, positive predictive value (PPV) = 0.992, negative predictive value (NPV) = 0.989, specificity = 0.989 and sensitivity = 0.992. The panel detected lung cancer independently of the disease stage. The 6-protein panel and other sub-combinations displayed excellent results in the validation dataset. In conclusion, we identified a blood-based 6-protein panel as a diagnostic tool in lung cancer. Used as a routine test for high- and average-risk individuals, it may complement currently adopted techniques in lung cancer screening.

Development of Benzenesulfonamide Derivatives as Potent Glutathione Transferase Omega-1 Inhibitors

Glutathione transferase omega-1 (GSTO1-1) is an enzyme whose function supports the activation of interleukin (IL)-1β and IL-18 that are implicated in a variety of inflammatory disease states for which small-molecule inhibitors are sought. The potent reactivity of the active-site cysteine has resulted in reported inhibitors that act by covalent labeling. In this study, structure-activity relationship (SAR) elaboration of the reported GSTO1-1 inhibitor C1-27 was undertaken. Compounds were evaluated for inhibitory activity toward purified recombinant GSTO1-1 and for indicators of target engagement in cell-based assays. As covalent inhibitors, the kinact/KI values of selected compounds were determined, as well as in vivo pharmacokinetics analysis. Cocrystal structures of key novel compounds in complex with GSTO1-1 were also solved. This study represents the first application of a biochemical assay for GSTO1-1 to determine kinact/KI values for tested inhibitors and the most extensive set of cell-based data for a GSTO1-1 inhibitor SAR series reported to date. Our research culminated in the discovery of 25, which we propose as the preferred biochemical tool to interrogate cellular responses to GSTO1-1 inhibition.

GSTO1*CC Genotype (rs4925) Predicts Shorter Survival in Clear Cell Renal Cell Carcinoma Male Patients

Omega class glutathione transferases, GSTO1-1 and GSTO2-2, exhibit different activities involved in regulation of inflammation, apoptosis and redox homeostasis. We investigated the the prognostic significance of GSTO1 (rs4925) and GSTO2 (rs156697 and rs2297235) polymorphisms in clear cell renal cell carcinoma (ccRCC) patients. GSTO1-1 and GSTO2-2 expression and phosphorylation status of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/ /mammalian target of rapamycin (mTOR) and Raf/MEK/extracellular signal-regulated kinase (ERK) signaling pathways in non-tumor and tumor ccRCC tissue, as well as possible association of GSTO1-1 with signaling molecules were also assessed. GSTO genotyping was performed by quantitative PCR in 228 ccRCC patients, while expression and immunoprecipitation were analyzed by Western blot in 30 tissue specimens. Shorter survival in male carriers of GSTO1*C/C wild-type genotype compared to the carriers of at least one variant allele was demonstrated (p = 0.049). GSTO1*C/C genotype independently predicted higher risk of overall mortality among male ccRCC patients (p = 0.037). Increased expression of GSTO1-1 and GSTO2-2 was demonstrated in tumor compared to corresponding non-tumor tissue (p = 0.002, p = 0.007, respectively), while GSTO1 expression was correlated with interleukin-1β (IL-1β)/pro-interleukin-1β (pro-IL-1β) ratio (r = 0.260, p = 0.350). Interaction of GSTO1 with downstream effectors of investigated pathways was shown in ccRCC tumor tissue. This study demonstrated significant prognostic role of GSTO1 polymorphism in ccRCC. Up-regulated GSTO1-1 and GSTO2-2 in tumor tissue might contribute to aberrant ccRCC redox homeostasis.

Autophagy modulators for the treatment of oral and esophageal squamous cell carcinomas

Oral squamous cell carcinomas (OSCC) and esophageal squamous cell carcinomas (ESCC) exhibit a survival rate of less than 60% and 40%, respectively. Late-stage diagnosis and lack of effective treatment strategies make both OSCC and ESCC a significant health burden. Autophagy, a lysosome-dependent catabolic process, involves the degradation of intracellular components to maintain cell homeostasis. Targeting autophagy has been highlighted as a feasible therapeutic strategy with clinical utility in cancer treatment, although its associated regulatory mechanisms remain elusive. The detection of relevant biomarkers in biological fluids has been anticipated to facilitate early diagnosis and/or prognosis for these tumors. In this context, recent studies have indicated the presence of specific proteins and small RNAs, detectable in circulating plasma and serum, as biomarkers. Interestingly, the interplay between biomarkers (eg, exosomal microRNAs) and autophagic processes could be exploited in the quest for targeted and more effective therapies for OSCC and ESCC. In this review, we give an overview of the available biomarkers and innovative targeted therapeutic strategies, including the application of autophagy modulators in OSCC and ESCC. Additionally, we provide a viewpoint on the state of the art and on future therapeutic perspectives combining the early detection of relevant biomarkers with drug discovery for the treatment of OSCC and ESCC.

Autoantibodies: Potential clinical applications in early detection of esophageal squamous cell carcinoma and esophagogastric junction adenocarcinoma

Esophageal squamous cell carcinoma (ESCC) and esophagogastric junction adenocarcinoma (EGJA) are the two main types of gastrointestinal cancers that pose a huge threat to human health. ESCC remains one of the most common malignant diseases around the world. In contrast to the decreasing prevalence of ESCC, the incidence of EGJA is rising rapidly. Early detection represents one of the most promising ways to improve the prognosis and reduce the mortality of these cancers. Current approaches for early diagnosis mainly depend on invasive and costly endoscopy. Non-invasive biomarkers are in great need to facilitate earlier detection for better clinical management of patients. Tumor-associated autoantibodies can be detected at an early stage before manifestations of clinical signs of tumorigenesis, making them promising biomarkers for early detection and monitoring of ESCC and EGJA. In this review, we summarize recent insights into the iden-tification and validation of tumor-associated autoantibodies for the early detection of ESCC and EGJA and discuss the challenges remaining for clinical validation.

Association of Glutathione-S-Transferases M1 and T1 Deletional Variants with Development of Oral Squamous Cell Carcinoma: A Study in the South-East of Iran

Background:

The role of genetic polymorphisms in genes of Glutathione-S-transferases (GST) enzymes in susceptibility to oral cavity cancers is controversial. Oral Squamous Cell Carcinoma (OSCC) is the most common oral cavity neoplasm. Aimed to evaluate the potential impacts of two well-known null variants residing in the gene encoding GSTM1 and GSTT1 enzymes of OSCC patients in the southeast of Iran.

Methods:

In a case-control design, 113 individuals (50 OSCC patients, and 63 healthy subjects) were included. DNA was extracted using paraffin-embedded tissues. GST genotyping was carried out using multiplex PCR.

Results:

In 113 participants, 41 (36.3%) and 72 (63.7%) were males and females respectively. No significant difference was recognized for distribution of GSTM1 (P=0.11) and GSTT1 (P=0.28) null genotypes between OSCC patients (58%, and 24% respectively) and healthy controls (42.9% and 15.9% respectively). Also, no significant difference was noted regarding the frequency of GSTM1 null genotype in different histological grades, however, those patients with more aggressive disease (poorly differentiated or grade III) revealed with a significantly higher ratio (66.7%) of GSTT1 null genotype (P=0.002). The highest odds ratio for OSCC was related to combined null genotypes for GSTM1 and GSTT1 (OR=2.5, 95% CI: 0.7-9.2), however, this was not statistically significant finding (P=0.15).

Conclusion:

Null genotypes polymorphisms were more common in OSCC than healthy individuals. GSTT1 null genotype may be an important genetic factor in the progression of OSCC.

Photoreceptor Survival Is Regulated by GSTO1-1 in the Degenerating Retina

Purpose

Glutathione-S-transferase omega 1-1 (GSTO1-1) is a cytosolic glutathione transferase enzyme, involved in glutathionylation, toll-like receptor signaling, and calcium channel regulation. GSTO1-1 dysregulation has been implicated in oxidative stress and inflammation, and contributes to the pathogenesis of several diseases and neurological disorders; however, its role in retinal degenerations is unknown. The aim of this study was to investigate the role of GSTO1-1 in modulating oxidative stress and consequent inflammation in the normal and degenerating retina.

Methods

The role of GSTO1-1 in retinal degenerations was explored by using Gsto1-/- mice in a model of retinal degeneration. The expression and localization of GSTO1-1 were investigated with immunohistochemistry and Western blot. Changes in the expression of inflammatory (Ccl2, Il-1β, and C3) and oxidative stress (Nox1, Sod2, Gpx3, Hmox1, Nrf2, and Nqo1) genes were investigated via quantitative real-time polymerase chain reaction. Retinal function in Gsto1-/- mice was investigated by using electroretinography.

Results

GSTO1-1 was localized to the inner segment of cone photoreceptors in the retina. Gsto1-/- photo-oxidative damage (PD) mice had decreased photoreceptor cell death as well as decreased expression of inflammatory (Ccl2, Il-1β, and C3) markers and oxidative stress marker Nqo1. Further, retinal function in the Gsto1-/- PD mice was increased as compared to wild-type PD mice.

Conclusions

These results indicate that GSTO1-1 is required for inflammatory-mediated photoreceptor death in retinal degenerations. Targeting GSTO1-1 may be a useful strategy to reduce oxidative stress and inflammation and ameliorate photoreceptor loss, slowing the progression of retinal degenerations.

Integrated phenotypic screening and activity-based protein profiling to reveal potential therapy targets of pancreatic cancer

Pancreatic cancer has been defined as one of the most complex and challenging cancers to treat, but very few valid therapeutic targets have been identified to date. To address this issue, a 61-compound library was readily created by Ugi reaction followed by phenotypic screening, leading to the discovery of two most potent inhibitors, P21 and P26, which significantly impair BxPC-3 pancreatic cancer cell survival. A series of interacting protein hits, such as GSTO1, FAM213A, RAB6A/6B/39A and USMG5, were subsequently identified by quantitative chemoproteomics studies. The main cellular target, GSTO1, was further validated as a novel pancreatic cancer therapeutic target.

Glutathione Transferases: Potential Targets to Overcome Chemoresistance in Solid Tumors

Multifunctional enzymes glutathione transferases (GSTs) are involved in the development of chemoresistance, thus representing a promising target for a novel approach in cancer treatment. This superfamily of polymorphic enzymes exhibits extraordinary substrate promiscuity responsible for detoxification of numerous conventional chemotherapeutics, at the same time regulating signaling pathways involved in cell proliferation and apoptosis. In addition to upregulated GST expression, different cancer cell types have a unique GST signature, enabling targeted selectivity for isoenzyme specific inhibitors and pro-drugs. As a result of extensive research, certain GST inhibitors are already tested in clinical trials. Catalytic properties of GST isoenzymes are also exploited in bio-activation of specific pro-drugs, enabling their targeted accumulation in cancer cells with upregulated expression of the appropriate GST isoenzyme. Moreover, the latest approach to increase specificity in treatment of solid tumors is development of GST pro-drugs that are derivatives of conventional anti-cancer drugs. A future perspective is based on the design of new drugs, which would selectively target GST overexpressing cancers more prone to developing chemoresistance, while decreasing side effects in off-target cells.

Diagnostic Value of the Survivin Autoantibody in Four Types of Malignancies

BACKGROUND

Tumor-associated antigen overexpression, which has been reported in many types of cancers, may trigger autoantibody secretion. The present study was designed to test whether levels of circulating autoantibodies to survivin protein-derived antigens is altered in liver, esophageal, breast, and lung cancers.

METHODS

Patients with liver (144), esophageal (159), breast (124), and lung cancers (267), and healthy volunteers (362) were recruited for the study, and serum samples were collected for ELISA autoantibody analysis.

RESULTS

Compared with the control group, survivin autoantibody levels were significantly higher in serum from patients with breast cancer and lung cancer, but were significantly lower in serum from patients with liver cancer (p < 0.05). In stage I and II lung cancer, the best-fit areas under the receiver operating characteristic curve was 0.731 (standard error [SE] = 0.023; 95% confidence interval [CI] 0.687-0.776) and the sensitivity, with 90% specificity, was 23.7%.

CONCLUSION

Analysis across four types of malignancies revealed that the survivin autoantibody had good specificity and sensitivity in lung cancer. Circulating autoantibodies to survivin could be a potential biomarker for the early lung cancer diagnosis.

Reviewing Hit Discovery Literature for Difficult Targets: Glutathione Transferase Omega-1 as an Example

Early stage drug discovery reporting on relatively new or difficult targets is often associated with insufficient hit triage. Literature reviews of such targets seldom delve into the detail required to critically analyze the associated screening hits reported. Here we take the enzyme glutathione transferase omega-1 (GSTO1-1) as an example of a relatively difficult target and review the associated literature involving small-molecule inhibitors. As part of this process we deliberately pay closer-than-usual attention to assay interference and hit quality aspects. We believe this Perspective will be a useful guide for future development of GSTO1-1 inhibitors, as well serving as a template for future review formats of new or difficult targets.

Inhibition of glutathione metabolism attenuates esophageal cancer progression

Esophageal squamous cell carcinoma (ESCC) is a deadly malignancy with regard to mortality and prognosis, and the 5-year survival rate for all patients diagnosed with ESCC remains poor. A better understanding of the biological mechanisms of ESCC tumorigenesis and progression is of great importance to improve treatment of this disease. In this study, we demonstrated that the glutathione metabolism pathway is highly enriched in ESCC cells compared with normal esophageal epithelial cells in an in vivo mouse model. In addition, treatment with L-buthionine-sulfoximine (BSO) to deplete glutathione decreased the ESCC tumor burden in mice, thus demonstrating the critical role of glutathione metabolism in ESCC progression. BSO treatment also led to decreased cell proliferation and activation of cell apoptosis in ESCC. Finally, BSO treatment blocked NF-kB pathway activation in ESCC. Our study reveals a new pathway that regulates ESCC progression and suggests that inhibition of glutathione metabolism may be a potential strategy for ESCC treatment.

Upregulated glutathione transferase omega-1 correlates with progression of urinary bladder carcinoma

OBJECTIVES

Newly discovered glutathione transferase omega 1 (GSTO1-1) plays an important role in the glutathionylation cycle, a significant mechanism of protein function regulation. GSTO1-1 expression pattern has not been studied in transitional cell carcinoma (TCC), as yet.

METHODS

A total of 56 TCC tumor and corresponding non-tumor specimens were investigated. Glutathione content and thioltransferase activity were measured spectrophotometrically. Protein-glutathione mixed disulfides were measured fluorimetrically. GSTO1-1 expression was determined by immunoblot and qPCR. Immunoprecipitation with GSTO1-1 antibody was followed by immunoblot using anti-GSTO1, GSTP1, c-Jun, JNK, Akt, phospho-Akt, and ASK1 antibody, while for the total S-glutathionylation levels non-reducing electrophoresis was performed.

RESULTS

The contents of reduced glutathione and thioltransferase activity were significantly increased in tumor compared to non-tumor tissue. The increased GSTO1 expression in tumor tissue showed clear correlation with grade and stage. However, decreased total protein glutathionylation level in tumor compared to non-tumor samples was found. Immunoprecipitation has shown an association of GSTO1-1 with GSTP1, Akt, phospho-Akt, and ASK1 proteins.

CONCLUSIONS

GSTO1 deglutathionylase activity suggests its potential important role in redox perturbations present in TCC. Increased GSTO1-1 expression might contribute to TCC development and/or progression supporting the notion that GSTO1-1 may be a promising novel cancer target.

Cell-specific biomarkers and targeted biopharmaceuticals for breast cancer treatment

Breast cancer is the second leading cause of cancer death among women, and its related treatment has been attracting significant attention over the past decades. Among the various treatments, targeted therapy has shown great promise as a precision treatment, by binding to cancer cell-specific biomarkers. So far, great achievements have been made in targeted therapy of breast cancer. In this review, we first discuss cell-specific biomarkers, which are not only useful for classification of breast cancer subtyping but also can be utilized as goals for targeted therapy. Then, the innovative and generic-targeted biopharmaceuticals for breast cancer, including monoclonal antibodies, non-antibody proteins and small molecule drugs, are reviewed. Finally, we provide our outlook on future developments of biopharmaceuticals, and provide solutions to problems in this field.

Structure, function and disease relevance of Omega-class glutathione transferases

The Omega-class cytosolic glutathione transferases (GSTs) have distinct structural and functional attributes that allow them to perform novel roles unrelated to the functions of other GSTs. Mammalian GSTO1-1 has been found to play a previously unappreciated role in the glutathionylation cycle that is emerging as significant mechanism regulating protein function. GSTO1-1-catalyzed glutathionylation or deglutathionylation of a key signaling protein may explain the requirement for catalytically active GSTO1-1 in LPS-stimulated pro-inflammatory signaling through the TLR4 receptor. The observation that ML175 a specific GSTO1-1 inhibitor can block LPS-stimulated inflammatory signaling has opened a new avenue for the development of novel anti-inflammatory drugs that could be useful in the treatment of toxic shock and other inflammatory disorders. The role of GSTO2-2 remains unclear. As a dehydroascorbate reductase, it could contribute to the maintenance of cellular redox balance and it is interesting to note that the GSTO2 N142D polymorphism has been associated with multiple diseases including Alzheimer's disease, Parkinson's disease, familial amyotrophic lateral sclerosis, chronic obstructive pulmonary disease, age-related cataract and breast cancer.

Oesophageal squamous cell carcinoma (ESCC): Advances through omics technologies, towards ESCC salivaomics

Oesophageal Squamous Cell Carcinoma (ESCC) is one of the two main subtypes of oesophageal cancer, affecting mainly populations in Asia. Though there have been great efforts to develop methods for a better prognosis, there is still a limitation in the staging of this affection. As a result, ESCC is detected at advances stages, when the interventions on the patient do not have such a positive outcome, leading in many cases to recurrence and to a very low 5-year survival rate, causing high mortality. A way to decrease the number of deaths is the use of biomarkers that can trace the advance of the disease at early stages, when surgical or chemotherapeutic methodologies would have a greater effect on the evolution of the subject. The new high throughput omics technologies offer an unprecedented chance to screen for thousands of molecules at the same time, from which a new set of biomarkers could be developed. One of the most convenient types of samples is saliva, an accessible body fluid that has the advantage of being non-invasive for the patient, being easy to store or to process. This review will focus on the current status of the new omics technologies regarding salivaomics in ESCC, or when not evaluated yet, the achievements in related diseases.