Aldoketoreductase family 1B10 (AKR1B10) as a biomarker to distinguish hepatocellular carcinoma from benign liver lesions

Development of a novel diagnostic model to monitor the progression of metabolic dysfunction-associated steatotic liver disease to hepatocellular carcinoma in females

BACKGROUND AND AIMS

The onset of metabolic dysfunction-associated steatotic liver disease-associated hepatocellular carcinoma (MASLD-HCC) is insidious and exhibits sex-specific variations. Effective methods for monitoring MASLD-HCC progression in females have not yet been developed.

METHODS

Transcriptomic data of female liver tissue samples were obtained from multiple public databases. Differentially expressed genes (DEGs) in MASLD-HCC were identified using differential expression and robust rank aggregation analyses. Diagnostic prediction models for MASLD (DP.MASLD) and HCC (DP.HCC) were developed and validated using elastic net analysis, and diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. Bioinformatics was used to assess the pathogenesis of MASLD-HCC.

RESULTS

Seven overlapping DEGs were identified in female patients with MASLD and HCC: AKR1B10, CLEC1B, CYP2C19, FREM2, MT1H, NRG1, and THBS1). The area under the ROC curve (AUC) values for the training and validation groups of the DP.MASLD model were 0.864 and 0.782, 0.932 and 1.000, and 0.920 and 0.969 when differentiating between the steatosis and normal liver, steatohepatitis and steatosis, and steatohepatitis and normal liver groups, respectively. The AUCs for DP.HCC were 0.980 and 0.997 in the training and validation groups, respectively. The oncogenesis of female MASLD-HCC is associated with molecular pathways, including cytochrome P450-associated drug metabolism, tyrosine metabolism, fatty acid degradation, focal adhesion, extracellular matrix receptor interactions, and protein digestion and absorption.

CONCLUSION

A novel and effective method to quantitatively assess the risk of MASLD-HCC progression in female patients was developed, and this method will aid in the generation of precise diagnostic, preventive, and therapeutic strategies.

Aldo-keto reductases: Role in cancer development and theranostics

Aldo-keto reductases (AKRs) are a superfamily of enzymes that play crucial roles in various cellular processes, including the metabolism of xenobiotics, steroids, and carbohydrates. A growing body of evidence has unveiled the involvement of AKRs in the development and progression of various cancers. AKRs are aberrantly expressed in a wide range of malignant tumors. Dysregulated expression of AKRs enables the acquisition of hallmark traits of cancer by activating oncogenic signaling pathways and contributing to chemoresistance. AKRs have emerged as promising oncotherapeutic targets given their pivotal role in cancer development and progression. Inhibition of aldose reductase (AR), either alone or in combination with chemotherapeutic drugs, has evolved as a pragmatic therapeutic option for cancer. Several classes of synthetic aldo-keto reductase (AKR) inhibitors have been developed as potential anticancer agents, some of which have shown promise in clinical trials. Many AKR inhibitors from natural sources also exhibit anticancer effects. Small molecule inhibitors targeting specific AKR isoforms have shown promise in preclinical studies. These inhibitors disrupt the activation of oncogenic signaling by modulating transcription factors and kinases and sensitizing cancer cells to chemotherapy. In this review, we discuss the physiological functions of human AKRs, the aberrant expression of AKRs in malignancies, the involvement of AKRs in the acquisition of cancer hallmarks, and the role of AKRs in oncogenic signaling, and drug resistance. Finally, the potential of aldose reductase inhibitors (ARIs) as anticancer drugs is summarized.

A Novel lncRNA lncRNA-4045 Promotes the Progression of Hepatocellular Carcinoma by Affecting the Expression of AKR1B10

BACKGROUND

Long noncoding RNAs (lncRNAs) have been shown to be related to the occurrence and development of a variety of cancers including hepatocellular carcinoma (HCC). However, a large number of potential HCC-related lncRNAs remain undiscovered and are yet to be fully understood.

METHODS

Differentially expressed lncRNAs were first obtained from the tumor tissues and adjacent normal tissues of five HCC patients using high-throughput microarray chips. Then the expression levels of 10 differentially expressed lncRNAs were verified in 50 pairs of tissue samples from patients with HCC by quantitative real-time PCR (qRT-PCR). The oncogenic effects of lncRNA-4045 (ENST00000524045.6) in HCC cell lines were verified through a series of in vitro experiments including CCK-8 assay, plate clone formation assay, transwell assay, scratch assay, and flow cytometry. Subsequently, the potential target genes of lncRNA-4045 were predicted by bioinformatics analysis, fluorescence in situ hybridization assay, and RNA sequencing. The mechanism of lncRNA-4045 in HCC was explored by WB assay as well as rescue and enhancement experiments.

RESULTS

The results from microarray chips showed 1,708 lncRNAs to have been significantly upregulated and 2725 lncRNAs to have been significantly downregulated in HCC tissues. Via validation in 50 HCC patients, a novel lncRNA lncRNA-4045 was found significantly upregulated in HCC tissues. Additionally, a series of in vitro experiments showed that lncRNA-4045 promoted the proliferation, invasion, and migration of HCC cell lines, and inhibited the apoptosis of HCC cell lines. The results of qRT-PCR in HCC tissues showed that the expression levels of AKR1B10 were significantly positively correlated with lncRNA-4045. LncRNA-4045 knockdown significantly down-regulated AKR1B10 protein expression, and overexpression of lncRNA-4045 led to significant up-regulation of AKR1B10 protein in HCC cell lines. Lastly, down-regulation of AKR1B10 could partially eliminate the enhancement of cell proliferation induced by lncRNA-4045 overexpression, while up-regulation of AKR1B10 was shown to enhance those effects.

CONCLUSION

LncRNA-4045 may promote HCC via enhancement of the expression of AKR1B10 protein.

AKR1B10 expression characteristics in hepatocellular carcinoma and its correlation with clinicopathological features and immune microenvironment

Hepatocellular carcinoma (HCC) represents a major global health threat with diverse and complex pathogenesis. Aldo-keto reductase family 1 member B10 (AKR1B10), a tumor-associated enzyme, exhibits abnormal expression in various cancers. However, a comprehensive understanding of AKR1B10's role in HCC is lacking. This study aims to explore the expression characteristics of AKR1B10 in HCC and its correlation with clinicopathological features, survival prognosis, and tumor immune microenvironment, further investigating its role and potential regulatory mechanisms in HCC. This study conducted comprehensive analyses using various bioinformatics tools and databases. Initially, differentially expressed genes related to HCC were identified from the GEO database, and the expression of AKR1B10 in HCC and other cancers was compared using TIMER and GEPIA databases, with validation of its specificity in HCC tissue samples using the HPA database. Furthermore, the relationship of AKR1B10 expression with clinicopathological features (age, gender, tumor size, staging, etc.) of HCC patients was analyzed using the TCGA database's LIHC dataset. The impact of AKR1B10 expression levels on patient prognosis was evaluated using Kaplan-Meier survival analysis and the Cox proportional hazards model. Additionally, the correlation of AKR1B10 expression with tumor biology-related signaling pathways and tumor immune microenvironment was studied using databases like GSEA, Targetscan, and others, identifying microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) that regulate AKR1B10 expression to explore potential regulatory mechanisms. Elevated AKR1B10 expression was significantly associated with gender, primary tumor size, and fibrosis stage in HCC tissues. High AKR1B10 expression indicated poor prognosis and served as an independent predictor for patient outcomes. Detailed mechanism analysis revealed a positive correlation between high AKR1B10 expression, immune cell infiltration, and pro-inflammatory cytokines, suggesting a potential DANCR-miR-216a-5p-AKR1B10 axis regulating the tumor microenvironment and impacting HCC development and prognosis. The heightened expression of AKR1B10 in HCC is not only related to significant clinical-pathological traits but may also influence HCC progression and prognosis by activating key signaling pathways and altering the tumor immune microenvironment. These findings provide new insights into the role of AKR1B10 in HCC pathogenesis and highlight its potential as a biomarker and therapeutic target.

Serum Aldo-Keto Reductase Family 1 Member B10 (AKR1B10) as a Potential Biomarker for Diagnosis of Hepatocellular Carcinoma

Objective

To evaluate the diagnostic performance of aldo-keto reductase family 1 member B10 (AKR1B10) in a Beijing cohort with hepatocellular carcinoma (HCC).

Methods

This study included 521 subjects who visited Peking Union Medical College Hospital from June 2017 to May 2023, including 109 cases of HCC, 165 cases of healthy controls, 106 cases of benign liver diseases, and 141 cases of other cancers. Serum AKR1B10 levels were measured and compared across various groups. Diagnostic performances of serum AKR1B10 and other tumor markers were assessed using receiver operator characteristic (ROC) curves. In addition, a subset of HCC patients who underwent surgical resection were recruited for clinical follow-up study.

Results

We found that serum AKR1B10 expression was higher in patients with HCC relative to other control groups. The association between serum AKR1B10 and clinical features of HCC was not observed. Serum AKR1B10 showed a high diagnostic performance for HCC, and when combined with AFP, the diagnostic effectiveness was significantly improved. Specifically, serum AKR1B10 showed superior diagnostic effectiveness for AFP-negative HCC. The clinical follow-up study indicated a gradual decrease in serum AKR1B10 after surgery.

Conclusion

Our study demonstrated that serum AKR1B10 is a promising biomarker for HCC, and when used in combination with AFP can significantly improve the detection rate of HCC.

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

Updating the Clinical Application of Blood Biomarkers and Their Algorithms in the Diagnosis and Surveillance of Hepatocellular Carcinoma: A Critical Review

The most common primary liver cancer is hepatocellular carcinoma (HCC), and its mortality rate is increasing globally. The overall 5-year survival of patients with liver cancer is currently 10-20%. Moreover, because early diagnosis can significantly improve prognosis, which is highly correlated with tumor stage, early detection of HCC is critical. International guidelines advise using α-FP biomarker with/without ultrasonography for HCC surveillance in patients with advanced liver disease. However, traditional biomarkers are sub-optimal for risk stratification of HCC development in high-risk populations, early diagnosis, prognostication, and treatment response prediction. Since about 20% of HCCs do not produce α-FP due to its biological diversity, combining α-FP with novel biomarkers can enhance HCC detection sensitivity. There is a chance to offer promising cancer management methods in high-risk populations by utilizing HCC screening strategies derived from new tumor biomarkers and prognostic scores created by combining biomarkers with distinct clinical parameters. Despite numerous efforts to identify molecules as potential biomarkers, there is no single ideal marker in HCC. When combined with other clinical parameters, the detection of some biomarkers has higher sensitivity and specificity in comparison with a single biomarker. Therefore, newer biomarkers and models, such as the Lens culinaris agglutinin-reactive fraction of Alpha-fetoprotein (α-FP), α-FP-L3, Des-γ-carboxy-prothrombin (DCP or PIVKA-II), and the GALAD score, are being used more frequently in the diagnosis and prognosis of HCC. Notably, the GALAD algorithm was effective in HCC prevention, particularly for cirrhotic patients, regardless of the cause of their liver disease. Although the role of these biomarkers in surveillance is still being researched, they may provide a more practical alternative to traditional imaging-based surveillance. Finally, looking for new diagnostic/surveillance tools may help improve patients' survival. This review discusses the current roles of the most used biomarkers and prognostic scores that may aid in the clinical management of HCC patients.

Transcriptomic Analysis of Hepatitis B Infected Liver for Prediction of Hepatocellular Carcinoma

Hepatocellular cancer (HCC) is a leading cause of cancer-related mortality worldwide, and chronic hepatitis B virus infection (CHB) has been a major risk factor for HCC development. The pathogenesis of HBV-related HCC has been a major focus revealing the interplay of a multitude of intracellular signaling pathways, yet the precise mechanisms and their implementations to clinical practice remain to be elucidated. This study utilizes publicly available transcriptomic data from the livers of CHB patients in order to identify a population with a higher risk of malignant transformation. We report the identification of a novel list of genes (PCM1) which can generate clear transcriptomic sub-groups among HBV-infected livers. PCM1 includes genes related to cell cycle activity and liver cancer development. In addition, markers of inflammation, M1 macrophages and gamma delta T cell infiltration are present within the signature. Genes within PCM1 are also able to differentiate HCC from normal liver, and some genes within the signature are associated with poor prognosis of HCC at the mRNA level. The analysis of the immunohistochemical stainings validated that proteins coded by a group of PCM1 genes were overexpressed in liver cancer, while minimal or no expression was detected in normal liver. Altogether, our findings suggest that PCM1 can be developed into a clinically applicable method to identify CHB patients with a higher risk of HCC development.

Clinical value of AKR1B10 in hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND

To evaluate the clinical value of Aldo-keto reductase family 1 member B10 (AKR1B10) in the diagnosis and prognosis of hepatocellular carcinoma (HCC).

METHODS

A search of the PubMed, China Biology Medicine, Cochrane, and Embase databases was performed to conduct meta-analyses to evaluate the accuracy of AKR1B10 in diagnosing HCC and to assess the impact on prognosis of patients after curative resection of HCC.

RESULTS

A total of 12 different cohorts from 11 studies including 2747 HCC patients and 2053 controls showed that the pooled specificity and the pooled sensitivity of AKR1B10 for the diagnosis of HCC were 0.78 (95% CI: 0.69-0.85) and 0.85 (95% CI: 0.77-0.90), respectively. The pooled sensitivity and specificity of serum AKR1B10 for the diagnosis of HCC were 0.80 (95% CI: 0.70-0.86) and 0.87 (95% CI: 0.77-0.93), respectively. The pooled sensitivity and specificity of AKR1B10 in malignant tumor tissue for the diagnosis of HCC were 0.78 (95% CI: 0.61-0.89) and 0.82 (95% CI: 0.69-0.90), respectively. The pooled sensitivity and specificity of AKR1B10 to distinguish HCC from benign liver disease were 0.71 (95% CI: 0.62-0.78) and 0.84 (95% CI: 0.77-0.89), respectively. The sensitivity and specificity of AKR1B10 combined with alpha fetoprotein (AFP) in the diagnosis of HCC were 0.84 (95% CI: 0.79-0.88) and 0.88 (95% CI: 0.73-0.95), respectively. The pooled sensitivity and specificity of AKR1B10 in malignant tumor tissue for the diagnosis of early-stage HCC were 0.85 (95% CI: 0.62-0.95) and 0.88 (95% CI: 0.81-0.93), respectively. A meta-analysis of five studies including 798 patients demonstrated that high AKR1B10 expression in liver malignant tumor was associated with better overall survival in patients with HCC after hepatectomy (HR = 0.54, 95% CI: 0.41-0.72, p < 0.001).

CONCLUSIONS

AKR1B10 exhibits a great clinical value in the diagnosis of HCC, especially for early-stage HCC, with excellent diagnostic accuracy. Furthermore, AKR1B10 expression can predict the prognosis of HCC patients after hepatic resection.

Inhibition of human carbonyl reducing enzymes by plant anthrone and anthraquinone derivatives

Members of the aldo-keto reductase and short-chain dehydrogenase/reductase enzyme superfamilies catalyze the conversion of a wide range of substrates, including carbohydrates, lipids, and steroids. These enzymes also participate in the transformation of xenobiotics, inactivation of the cytostatics doxo- and daunorubicin, and play a role in the development of cancer. Therefore, inhibitors of such enzymes may improve therapeutic outcomes. Plant-derived compounds such as anthraquinones have been used for medicinal purposes for several centuries. In the current study, the inhibitory potential of selected anthrone and anthraquinone derivatives (from plants) was tested on six recombinant human carbonyl reducing enzymes (AKR1B1, AKR1B10, AKR1C3, AKR7A2, AKR7A3, CBR1) isolated from an Escherichia coli expression system. Overall, the least inhibition was observed with the anthrone derivative aloin, while IC50 values obtained with the anthraquinone derivatives (frangula emodin, aloe emodin, frangulin A, and frangulin B) and the aldo-keto reductase AKR1B10 were in the low micromolar range (3.5-16.6 μM). AKR1B1 inhibition was significantly weaker in comparison with AKR1B10 inhibition (IC50 values > 50 μM). The strongest inhibition was observed with the short-chain dehydrogenase/reductase CBR1. AKR7A2, AKR7A3, and AKR1C3 were not, or less inhibited by inhibitor concentrations of up to 50 μM. Analysis of the kinetic data suggests noncompetitive or uncompetitive inhibition mechanisms. The new inhibitors described here may serve as lead structures for the development of future drugs.

Predictive Role for Serum Aldo-Keto Reductase Family1 Member B10 for Early Detection of Hepatocellular Carcinoma in Egyptian Patients

Background: Most patients with hepatocellular carcinoma (HCC) are diagnosed at late stages despite of improvement screening programs and lack of effective diagnostic methods for cases with preclinical HCC leads to a low rate of early detection. Aldo-keto reductase family 1 member B10 (AKR1B10) is associated with several types of cancer. However, to our knowledge, the diagnostic significance of AKR1B10 measurement in early stage of HCC has poorly understood. Aim To evaluate the diagnostic performance of serum AKR1B10 in hepatitis C virus (HCV)-related liver disorders and its unique role in diagnosing HCC. Methods Serum AKR1B10 was detected by sandwich ELISA in 30 patients with HCV-related HCC, 30 patients with HCV related liver cirrhosis, and 20 healthy controls. Both Serum AKR1B10 and α-fetoprotein (AFP) levels were analyzed, evaluated and compared. Results Serum AKR1B10 was significantly elevated in patients with HCC compared with. The sensitivity (86.7.0%) and specificity (70%) for HCC diagnosis with AKR1B10 were high at a cutoff value of 0.945 ng/ml, while alpha fetoprotein had sensitivity 67% and specificity 88% in early detection of HCC among studied groups at cutoff point higher than 17.9. ng/ml. Furthermore, concurrent measurement of Alpha fetoprotein and AKR1B10 had increased sensitivity to 97.6% and specificity 100% in early detection of HCC among studied groups at cutoff point higher than ≥150 ng/ml. Furthermore, concurrent measurement of serum AKR1B10 and AFP significantly increased sensitivity and negative predictive value for HCC diagnosis. Conclusions we concluded in the current study that AKR1B10 has a unique role as a biomarker for early-stage HCV-related HCC. Compared with AFP alone, a combination of serum AKR1B10 and AFP had an increased the diagnostic performance in patients with HCC.

The prominence of potential biomarkers in the diagnosis and management of hepatocellular carcinoma: Current scenario and future anticipation

Hepatocellular carcinoma (HCC) is one of the most aggressive and truculent types of cancer. Early detection of HCC is a massive concern that can boost the overall survival rates of HCC patients. As a result, there is a continual quest for advancements in screening, diagnosis, and treatment strategies to enhance the prognosis at its early stages. However, the confluence of inflammation and cirrhosis hampers the early detection of HCC. The analysis of different types of biomarkers such as tissue biomarkers, serum biomarkers, protein biomarkers, autoantibody markers, and improved imaging techniques has played a vital role in ameliorating HCC monitoring responses. Therefore biomarkers that can identify HCC early with a high degree of sensitivity and specificity might be prodigiously serviceable in the diagnosis and treatment of this notorious disorder. This study offers an overview of the contemporary understanding of several types of biomarkers implicated in hepatocarcinogenesis and their applications in monitoring, diagnosis, and prognosis presage. In additament, we address the role of image techniques associated with HCC diagnosis.

Anticancer activity of oleanolic acid and its derivatives: Recent advances in evidence, target profiling and mechanisms of action

Oleanolic acid (OA, 3 β - hydroxyoleanolic acid-12-en-28-oic acid) is a pentacyclic triterpenoid present in many plants. As a new framework for development of semi synthetic triterpenoids, OA is of great significance in the discovery of anticancer drugs. Some of these derivatives, such as CDDO (2-cyano-3,12-dioxooleana-1, 9 (11)-dien-28-oic acid) have been verified in clinical trials, while other derivatives studied previously, such as SZC014, SZC015 and SZC017 (OA derivatives respectively), are also candidate drugs for cancer treatment. This paper reviews the preclinical studies, literature evidence, target analysis and anticancer mechanism of OA and its derivatives. The mechanism of action of its derivatives mainly includes anti-cancer cell proliferation, inducing tumor cell apoptosis, inducing autophagy, regulating cell cycle regulatory proteins, inhibiting vascular endothelial growth, anti angiogenesis, inhibiting tumor cell migration and invasion. In recent years, the molecular mechanism of OA and its derivatives has been elucidated. These effects seem to be mediated by the alterations in a variety of signaling pathways induced by OA and its derivatives. In conclusion, OA and its derivatives are considered as important candidate drugs for the treatment of cancer, indicating that OA and its derivatives have the potential to be used as anticancer drugs in practice.

The expression and significance of AKR1B10 in laryngeal squamous cell carcinoma

Aldosterone reductase family 1 member B10 (AKR1B10) is a nicotinamide adenine dinucleotide phosphate (reduced coenzyme II)-dependent oxidoreductase, and its biological functions include carbonyl detoxification, hormone metabolism, osmotic adjustment, and lipid synthesis. Studies suggested that AKR1B10 is a new biomarker for cancer based on its overexpression in epithelial tumors, such as breast cancer, cervical cancer, and lung cancer. At present, studies on the expression of AKR1B10 in laryngeal cancer have not been reported. However, we found that AKR1B10 is upregulated in laryngeal carcinoma, and its expression was negatively correlated with the degree of differentiation. In addition, AKR1B10 expression was positively correlated with tumor size; lymph node metastasis; alcohol use; and Ki-67, mutant p53, and matrix metalloproteinase 2 expression. AKR1B10 was overexpressed in Hep-2 laryngeal carcinoma cells. Oleanolic acid inhibited AKR1B10 activity and expression in Hep-2 cells and suppressed Hep-2 cell proliferation, migration, and invasion. Therefore, AKR1B10 may be related to the development of laryngeal carcinoma, suggesting its use as a prognostic indicator for laryngeal cancer.

Identification of Aging-Related Genes Associated With Clinical and Prognostic Features of Hepatocellular Carcinoma

Background: Aging is a well-studied concept, but no studies have comprehensively analyzed the association between aging-related genes (AGs) and hepatocellular carcinoma (HCC) prognosis. Methods: Gene candidates were selected from differentially expressed genes and prognostic genes in The Cancer Genome Atlas (TCGA) database. A gene risk score for overall survival prediction was established using the least absolute shrinkage and selection operator (LASSO) regression analysis, and this was validated using data from the International Cancer Genome Consortium (ICGC) database. Functional analysis was conducted using gene ontology enrichment, Kyoto Encyclopedia of Genes and Genomes analysis, gene set enrichment analysis, and immune microenvironment and tumor stemness analyses. Results: Initially, 72 AGs from the TCGA database were screened as differentially expressed between normal and tumor tissues and as genes associated with HCC prognosis. Then, seven AGs (POLA1, CDK1, SOCS2, HDAC1, MAPT, RAE1, and EEF1E1) were identified using the LASSO regression analysis. The seven AGs were used to develop a risk score in the training set, and the risk was validated to have a significant prognostic value in the ICGC set (p < 0.05). Patients with high risk scores had lower tumor differentiation, higher stage, and worse prognosis (all p < 0.05). Multivariate Cox regression analyses also confirmed that the risk score was an independent prognostic factor for HCC in both the TCGA and ICGC sets (all p < 0.05). Further analysis showed that a high risk score was correlated with the downregulation of metabolism and tumor immunity. Conclusion: The risk score predicts HCC prognosis and could thus be used as a biomarker not only for predicting HCC prognosis but also for deciding on treatment.

Whole-transcriptome Analysis of Fully Viable Energy Efficient Glycolytic-null Cancer Cells Established by Double Genetic Knockout of Lactate Dehydrogenase A/B or Glucose-6-Phosphate Isomerase

BACKGROUND/AIM

Nearly all mammalian tumors of diverse tissues are believed to be dependent on fermentative glycolysis, marked by elevated production of lactic acid and expression of glycolytic enzymes, most notably lactic acid dehydrogenase (LDH). Therefore, there has been significant interest in developing chemotherapy drugs that selectively target various isoforms of the LDH enzyme. However, considerable questions remain as to the consequences of biological ablation of LDH or upstream targeting of the glycolytic pathway.

MATERIALS AND METHODS

In this study, we explore the biochemical and whole transcriptomic effects of CRISPR-Cas9 gene knockout (KO) of lactate dehydrogenases A and B [LDHA/B double KO (DKO)] and glucose-6-phosphate isomerase (GPI KO) in the human colon cancer cell line LS174T, using Affymetrix 2.1 ST arrays.

RESULTS

The metabolic biochemical profiles corroborate that relative to wild type (WT), LDHA/B DKO produced no lactic acid, (GPI KO) produced minimal lactic acid and both KOs displayed higher mitochondrial respiration, and minimal use of glucose with no loss of cell viability. These findings show a high biochemical energy efficiency as measured by ATP in glycolysis-null cells. Next, transcriptomic analysis conducted on 48,226 mRNA transcripts reflect 273 differentially expressed genes (DEGS) in the GPI KO clone set, 193 DEGS in the LDHA/B DKO clone set with 47 DEGs common to both KO clones. Glycolytic-null cells reflect up-regulation in gene transcripts typically associated with nutrient deprivation / fasting and possible use of fats for energy: thioredoxin interacting protein (TXNIP), mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), PPARγ coactivator 1α (PGC-1α), and acetyl-CoA acyltransferase 2 (ACAA2). Other changes in non-ergometric transcripts in both KOs show losses in "stemness", WNT signaling pathway, chemo/radiation resistance, retinoic acid synthesis, drug detoxification, androgen/estrogen activation, and extracellular matrix reprogramming genes.

CONCLUSION

These findings demonstrate that: 1) The "Warburg effect" is dispensable, 2) loss of the LDHAB gene is not only inconsequential to viability but fosters greater mitochondrial energy, and 3) drugs that target LDHA/B are likely to be ineffective without a plausible combination second drug target.

Quantitative analysis of mRNA expression levels of aldo-keto reductase and short-chain dehydrogenase/reductase isoforms in human livers

The aldo-keto reductase (AKR) and short-chain dehydrogenase/reductase (SDR) superfamilies are responsible for the reduction in compounds containing the aldehyde, ketone, and quinone groups. In humans, 12 AKR isoforms (AKR1A1, AKR1B1, AKR1B10, AKR1B15, AKR1C1, AKR1C2, AKR1C3, AKR1C4, AKR1D1, AKR1E2, AKR7A2, and AKR7A3) and 6 SDR isoforms (CBR1, CBR3, CBR4, HSD11B1, DHRS4, and DCXR) have been found to catalyze the reduction in xenobiotics, but their hepatic expression levels are unclear. The purpose of this study is to determine the absolute mRNA expression levels of these 18 isoforms in the human liver. In 22 human livers, all isoforms, except for AKR1B15, are expressed, and AKR1C2 (on average 1.6 × 10⁶ copy/μg total RNA), AKR1C3 (1.3 × 10⁶), AKR1C1 (1.3 × 10⁶), CBR1 (9.7 × 10⁵), and HSD11B1 (1.1 × 10⁶) are abundant, representing 67% of the total expression of reductases in the liver. The expression levels of AKR1C2, AKR1C3, AKR1C1, CBR1, and HSD11B1 are significantly correlated with each other, except between AKR1C2 and CBR1, suggesting that they might be regulated by common factor(s). In conclusion, this study comprehensively determined the absolute expression of mRNA expression of each AKR and SDR isoform in the human liver.

New Blood Biomarkers for the Diagnosis of AFP-Negative Hepatocellular Carcinoma

An early diagnosis of hepatocellular carcinoma (HCC) followed by effective treatment is currently critical for improving the prognosis and reducing the associated economic burden. Alpha-fetoprotein (AFP) is the most widely used biomarker for HCC diagnosis. Based on elevated serum AFP levels as well as typical imaging features, AFP-positive HCC (APHC) can be easily diagnosed, but AFP-negative HCC (ANHC) is not easily detected due to lack of ideal biomarkers and thus mainly reliance on imaging. Imaging for the diagnosis of ANHC is probably insufficient in sensitivity and/or specificity because most ANHC tumors are small and early-stage HCC, and it is involved in sophisticated techniques and high costs. Moreover, ANHC accounts for nearly half of HCC and exhibits a better prognosis compared with APHC. Therefore, the diagnosis of ANHC in clinical practice has been a critical issue for the early treatment and prognosis improvement of HCC. In recent years, tremendous efforts have been made to discover new biomarkers complementary to AFP for HCC diagnosis. In this review, we systematically review and discuss the recent advances of blood biomarkers for HCC diagnosis, including DNA biomarkers, RNA biomarkers, protein biomarkers, and conventional laboratory metrics, focusing on their diagnostic evaluation alone and in combination, in particular on their diagnostic performance for ANHC.

AKR1B10 Inhibitor Epalrestat Facilitates Sorafenib-Induced Apoptosis and Autophagy Via Targeting the mTOR Pathway in Hepatocellular Carcinoma

Sorafenib is the standard systemic treatment for advanced hepatocellular carcinoma (HCC), and improving its therapeutic effects is crucial for addressing cancer aggression. We previously reported that epalrestat, an aldo-keto reductase 1B10 inhibitor, enhanced sorafenib's inhibitory effects on HCC xenograft in nude mice. This study aimed to elucidate the mechanism of epalrestat's anti-tumour enhancing effects on sorafenib. HepG2 cells were treated with sorafenib, epalrestat, and their combination. Cell proliferation was assessed with Cell Counting Kit-8 and colony formation assays. AKR1B10 supernate concentration and enzyme activity were detected by ELISA assay and the decrease of optical density of NADPH at 340 nm. Cell cycle and apoptosis analyses were performed with flow cytometry. Western blots clarified the molecular mechanism underlying effects on cell cycle, apoptosis, and autophagy. The anti-tumour mechanism was then validated in vivo through TUNEL and immunohistochemistry staining of HCC xenograft sections. Epalrestat combined with sorafenib inhibited HepG2 cellular proliferation in vitro, arrested the cell cycle at G0/G1, and promoted apoptosis and autophagy. Treatment with a specific mTOR activator MHY-1485 increased mTOR phosphorylation, while suppressing apoptosis and autophagy. Consistent with in vitro results, data from the HCC-xenograft nude mouse model also indicated that combined treatment inhibited the mTOR pathway and promoted apoptosis and autophagy. In conclusion, epalrestat heightens sorafenib's anti-cancer effects via blocking the mTOR pathway, thus inducing cell cycle arrest, apoptosis, and autophagy.

Compensatory upregulation of aldo-keto reductase 1B10 to protect hepatocytes against oxidative stress during hepatocarcinogenesis

Aldo-keto reductase 1B10 (AKR1B10), a member of aldo-keto reductase superfamily, contributes to detoxification of xenobiotics and metabolization of physiological substrates. Although increased expression of AKR1B10 was found in hepatocellular carcinoma (HCC), the role of AKR1B10 in the development of HCC remains unclear. This study aims to illustrate the role of AKR1B10 in hepatocarcinogenesis based on its intrinsic oxidoreduction abilities. HCC cell lines with AKR1B10 overexpression or knockdown were treated with doxorubicin or hydrogen peroxide to determinate the influence of aberrant AKR1B10 expression on cells' response to oxidative stress. Using Akr1b8 (the ortholog of human AKR1B10) knockout mice, diethylnitrosamine (DEN) induced liver injury, chronic inflammation and hepatocarcinogenesis were explored. Clinically, the pattern of serum AKR1B10 relevant to disease progression was investigated in a patient cohort with chronic hepatitis B (n=30), liver cirrhosis (n=30) and HCC (n=40). AKR1B10 expression in HCC tissues was analyzed using both the TCGA database (n=371) and our collected HCC samples (n=67). AKR1B10 overexpression reduced hepatocyte injury while AKR1B10 knockdown augmented reactive oxygen species (ROS) accumulation and apoptotic cell death. Consistently, Akr1b8 deficiency in mice promoted DEN-induced hepatocyte damage and liver inflammation characterized by increased phospho-H2AX, serum alanine aminotransferase, interleukin-6 and tumor necrosis factor alpha level, myeloid cell infiltration and led to more severe hepatocarcinogenesis and metastasis compared with wild type mice due to significant alteration on detoxification and oxidoreduction. AKR1B10 was compensatory expressed and gradually upregulated in the process of liver disease progression in HCC and increased oxidative stress upregulated AKR1B10 through NRF2. Our results here suggested that through oxidoreduction and detoxification, AKR1B10 played an important role in protecting hepatocytes from damage induced by ROS. Deficiency of AKR1B10 might accelerate hepatotoxin and inflammation-associated hepatocarcinogenesis. AKR1B10 expression elevation in HCC could be a result of compensatory upregulation, rather than a driver of malignant transformation during the development of HCC.

Aldo-Keto Reductase Family 1 Member B10 (AKR1B10) overexpression in tumors predicts worse overall survival in hepatocellular carcinoma

Overexpression of AKR1B10 correlated with tumorigenesis of many human malignancies; however, the prognostic value of AKR1B10 expression in patients with hepatocellular carcinoma (HCC) still remains controversial. In this analysis, AKR1B10 expression in HCC tumors were evaluated in GEO, TCGA and Oncomine databases, and a survival analysis of AKR1B10 based on TCGA profile was performed. We found that AKR1B10 was significantly overexpressed in tumors compared with nontumors in 7 GEO series (GSE14520, GSE25097, GSE33006, GSE45436, GSE55092, GSE60502, GSE77314) and TCGA profile (all P < 0.05). Meta-analysis in Oncomine database revealed that AKR1B10 was significantly upregulated in cirrhosis, liver cell dysplasia and HCC compared with normal tissues (all P < 0.05). Kaplan-Meier analysis demonstrated that high AKR1B10 in tumors were significantly associated with worse overall survival (OS) in HCC patients (P < 0.05). Subgroup analysis showed that AKR1B10 overexpression were associated with poor 1-year, 3-year and 5-year OS (all P < 0.05). In addition, prognostic values of AKR1B10 upregulation for OS were more significant in HCC with hepatitis-virus-free (P = 0.00055), White race (P = 0.0029) and alcohol-free (P = 0.013), and both in male and female (P = 0.014 and P = 0.034, respectively). In conclusion: AKR1B10 was upregulated in tumors and correlated with worse OS in HCC patients.

A human liver cell atlas reveals heterogeneity and epithelial progenitors

The human liver is an essential multifunctional organ. The incidence of liver diseases is rising and there are limited treatment options. However, the cellular composition of the liver remains poorly understood. Here we performed single-cell RNA sequencing of about 10,000 cells from normal liver tissue from nine human donors to construct a human liver cell atlas. Our analysis identified previously unknown subtypes of endothelial cells, Kupffer cells, and hepatocytes, with transcriptome-wide zonation of some of these populations. We show that the EPCAM⁺ population is heterogeneous, comprising hepatocyte-biased and cholangiocyte populations as well as a TROP2^int progenitor population with strong potential to form bipotent liver organoids. As a proof-of-principle, we used our atlas to unravel the phenotypic changes that occur in hepatocellular carcinoma cells and in human hepatocytes and liver endothelial cells engrafted into a mouse liver. Our human liver cell atlas provides a powerful resource to enable the discovery of previously unknown cell types in normal and diseased livers.

Overexpression of AKR1B10 predicts tumor recurrence and short survival in oral squamous cell carcinoma patients

BACKGROUND

Aldo-keto reductase family 1 member B10 (AKR1B10) is an enzyme implicated in physiological xenobiotic detoxification and also in pathological carcinogenesis. Overexpression of AKR1B10 has been reported in oral squamous cell carcinoma (OSCC), but its correlation with clinical prognosis is controversial. The aim of this study was to investigate and clarify the role of AKR1B10 in OSCC carcinogenesis.

METHODS

Tumor tissue specimens were surgically obtained from 107 patients with OSCC. The expression of AKR1B10 was analyzed by immunohistochemistry to explore the relationship between the level of AKR1B10 and clinicopathological features of OSCC patients. Kaplan-Meier survival and Cox proportional hazard analysis were used to determine the prognostic value of AKR1B10 in OSCC.

RESULTS

High expression of AKR1B10 was found to be associated with tumor size (P = 0.043), perineural invasion (P = 0.012), and recurrence (P = 0.001) in OSCC. Cox model analysis revealed that high expression of AKR1B10 is significantly associated with poor overall and disease-free survival in OSCC patients. With the combination of clinicopathological factors in analysis, we found that the expression level of AKR1B10 was a practical indicator that could categorize OSCC patients into different risk groups. High expression of AKR1B10 was associated with a reduced survival in patients with well and moderately differentiated OSCC and even a high incidence of tumor recurrence in the patients with late-stage (III and IV) disease.

CONCLUSION

We validated and expanded data on the expression of AKR1B10 in OSCC, suggesting that it is a valuable biomarker for prognostic prediction of recurrence and survival in OSCC.

Metabolic adaptability in metastatic breast cancer by AKR1B10-dependent balancing of glycolysis and fatty acid oxidation

The different stages of the metastatic cascade present distinct metabolic challenges to tumour cells and an altered tumour metabolism associated with successful metastatic colonisation provides a therapeutic vulnerability in disseminated disease. We identify the aldo-keto reductase AKR1B10 as a metastasis enhancer that has little impact on primary tumour growth or dissemination but promotes effective tumour growth in secondary sites and, in human disease, is associated with an increased risk of distant metastatic relapse. AKR1B10^High tumour cells have reduced glycolytic capacity and dependency on glucose as fuel source but increased utilisation of fatty acid oxidation. Conversely, in both 3D tumour spheroid assays and in vivo metastasis assays, inhibition of fatty acid oxidation blocks AKR1B10^High-enhanced metastatic colonisation with no impact on AKR1B10^Low cells. Finally, mechanistic analysis supports a model in which AKR1B10 serves to limit the toxic side effects of oxidative stress thereby sustaining fatty acid oxidation in metabolically challenging metastatic environments.

Cancer cells must develop distinct metabolic adaptations to survive in challenging metastatic environments. Here, the authors find, via an in vivo RNAi screen, that the aldo-keto reductase AKR1B10 limits the toxic side effects of oxidative stress to sustain fatty acid oxidation and promote metastatic colonisation.

AKR1B10 (Aldo-keto reductase family 1 B10) promotes brain metastasis of lung cancer cells in a multi-organ microfluidic chip model

Brain metastasis (BM) is a leading cause of mortality in patients with non-small cell lung cancer (NSCLC). However, the molecular mechanisms underlying BM of NSCLC remain largely unknown because of the lack of models to accurately investigate such a dynamic and complex process. Here we developed a multi-organ microfluidic chip as a new methodological platform to study BM. The chip consisted of two bionic organ units - an upstream "lung" and a downstream "brain" characterized by a functional "blood-brain barrier (BBB)" structure, allowing real-time visual monitoring of the entire BM process, from the growth of primary tumor to its breaking through the BBB, and finally reaching the brain parenchyma. The chip was verified by lung cancer cell lines with differing metastatic abilities and then applied for the BM research where we first demonstrated that the protein expression of Aldo-keto reductase family 1 B10 (AKR1B10) was significantly elevated in lung cancer BM. Silencing AKR1B10 in brain metastatic tumor cells suppressed their extravasation through the BBB in the in vitro Transwell model, in our ex vivo microfluidic chip, as well as the in vivo model of brain metastasis in nude mice. Moreover, AKR1B10 downregulated the expression of matrix metalloproteinase (MMP)-2 and MMP-9 via MEK/ERK signaling in metastatic lung cancers. These data suggest that our multi-organ microfluidic chip is a practical alternative to study BM pathogenesis, and AKR1B10 is a diagnostic biomarker and a prospective therapeutic target for NSCLC BM. STATEMENT OF SIGNIFICANCE: Brain metastasis (BM) of non-small cell lung cancer (NSCLC) is a complex cascade, and in particular, the process of lung cancer cells penetrating the blood-brain barrier (BBB) is very unique. However, due to the lack of reliable models that can faithfully mimic the dynamic process of BBB breaking, its molecular mechanisms have not well elucidated so far. In addition, although Aldo-keto reductase family 1 B10 (AKR1B10) has been implicated to the tumor development of liver cancer and many other cancers, little is known on its roles in the BM. Here, we established a multi-organ microfluidic bionic chip platform to recapitulate the entire BM process, and applied it to the BM pathology research, especially BBB extravasation. By using the chip and traditional models synergistically, we first demonstrated that AKR1B10 was significantly elevated in lung cancer BM, and defined the value of AKR1B10 as a diagnostic serum biomarker for lung cancer patients suffering from BM. Further, we investigated the role and mechanisms of AKR1B10 in BM that it promotes the extravasation of cancer cells through the BBB.

A Large-Scale Multicenter Study Validates Aldo-Keto Reductase Family 1 Member B10 as a Prevalent Serum Marker for Detection of Hepatocellular Carcinoma

Aldo-keto reductase family 1 member B10 (AKR1B10) is a secretory protein overexpressed in hepatocellular carcinoma (HCC). We aimed to evaluate AKR1B10 as a serum marker for detection of HCC. Herein, we conducted a cohort study that consecutively enrolled 1,244 participants from three independent hospitals, including HCC, healthy controls (HCs), benign liver tumors (BLTs), chronic hepatitis B (CHB), and liver cirrhosis (LC). Serum AKR1B10 was tested by time-resolved fluorescent assays. Data were plotted for receiver operating characteristic (ROC) curve analyses. Alpha-fetoprotein (AFP) was analyzed for comparison. An exploratory discovery cohort demonstrated that serum AKR1B10 increased in patients with HCC (1,567.3 ± 292.6 pg/mL; n = 69) compared with HCs (85.7 ± 10.9 pg/mL; n = 66; P < 0.0001). A training cohort of 519 participants yielded an optimal diagnostic cutoff of serum AKR1B10 at 267.9 pg/mL. When ROC curve was plotted for HCC versus all controls (HC + BLT + CHB + LC), serum AKR1B10 had diagnostic parameters of the area under the curve (AUC) 0.896, sensitivity 72.7%, and specificity 95.7%, which were better than AFP with AUC 0.816, sensitivity 65.1%, and specificity 88.9%. Impressively, AKR1B10 showed promising diagnostic potential in early-stage HCC and AFP-negative HCC. Combination of AKR1B10 with AFP increased diagnostic accuracy for HCC compared with AKR1B10 or AFP alone. A validation cohort of 522 participants confirmed these findings. An independent cohort of 68 patients with HCC who were followed up showed that serum AKR1B10 dramatically decreased 1 day after operation and was nearly back to normal 3 days after operation. Conclusion: AKR1B10 is a potent serum marker for detection of HCC and early-stage HCC, with better diagnostic performance than AFP.

Diagnostic and Prognostic Potential of AKR1B10 in Human Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. Although diagnostic measures and surgical interventions have improved in recent years, the five-year survival rate for patients with advanced HCC remains bleak-a reality that is largely attributable to an absence of early stage symptoms, lack of adequate diagnostic and prognostic biomarkers, and the common occurrence of acquired resistance to chemotherapeutic agents during HCC treatment. A limited understanding of the molecular mechanisms underlying HCC pathogenesis also presents a challenge for the development of specific and efficacious pharmacological strategies to treat, halt, or prevent progression to advanced stages. Over the past decade, aldo-keto reductase family 1 member 10 (AKR1B10) has emerged as a potential biomarker for the diagnosis and prognosis of HCC, and experimental studies have demonstrated roles for this enzyme in biological pathways underlying the development and progression of HCC and acquired resistance to chemotherapeutic agents used in the treatment of HCC. Here we provide an overview of studies supporting the diagnostic and prognostic utility of AKR1B10, summarize the experimental evidence linking AKR1B10 with HCC and the induction of chemoresistance, and discuss the clinical value of AKR1B10 as a potential target for HCC-directed drug development. We conclude that AKR1B10-based therapies in the clinical management of specific HCC subtypes warrant further investigation.

Deregulation of the Genes that Are Involved in Drug Absorption, Distribution, Metabolism, and Excretion in Hepatocellular Carcinoma

Genes involved in drug absorption, distribution, metabolism, and excretion (ADME) are called ADME genes. Currently, 298 genes that encode phase I and II drug metabolizing enzymes, transporters, and modifiers are designated as ADME genes by the PharmaADME Consortium. ADME genes are highly expressed in the liver and their levels can be influenced by liver diseases such as hepatocellular carcinoma (HCC). In this study, we obtained RNA-sequencing and microRNA (miRNA)-sequencing data from 371 HCC patients via The Cancer Genome Atlas liver hepatocellular carcinoma project and performed ADME gene-targeted differential gene expression analysis and expression correlation analysis. Two hundred thirty-three of the 298 ADME genes (78%) were expressed in HCC. Of these genes, almost one-quarter (58 genes) were significantly downregulated, while only 6% (15) were upregulated in HCC relative to healthy liver. Moreover, one-half (14/28) of the core ADME genes (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2E1, CYP3A4, NAT1, NAT2, UGT2B7, SLC22A1, SLCO1B1, and SLCO1B3) were downregulated. In addition, about one-half of the core ADME genes were positively correlated with each other and were also positively (AHR, ARNT, HNF4A, PXR, CAR, PPARA, and RXRA) or negatively (PPARD and PPARG) correlated with transcription factors known as ADME modifiers. Finally, we show that most miRNAs known to regulate core ADME genes are upregulated in HCC. Collectively, these data reveal 1) an extensive transcription factor-mediated ADME coexpression network in the liver that efficiently coordinates the metabolism and elimination of endogenous and exogenous compounds; and 2) a widespread deregulation of this network in HCC, most likely due to deregulation of both transcriptional and post-transcriptional (miRNA) pathways.

The hop-derived compounds xanthohumol, isoxanthohumol and 8-prenylnaringenin are tight-binding inhibitors of human aldo-keto reductases 1B1 and 1B10

Xanthohumol (XN), a prenylated chalcone unique to hops (Humulus lupulus) and two derived prenylflavanones, isoxanthohumol (IX) and 8-prenylnaringenin (8-PN) gained increasing attention as potential anti-diabetic and cancer preventive compounds. Two enzymes of the aldo-keto reductase (AKR) superfamily are notable pharmacological targets in cancer therapy (AKR1B10) and in the treatment of diabetic complications (AKR1B1). Our results show that XN, IX and 8-PN are potent uncompetitive, tight-binding inhibitors of human aldose reductase AKR1B1 (Ki = 15.08 μM, 0.34 μM, 0.71 μM) and of human AKR1B10 (Ki = 20.11 μM, 2.25 μM, 1.95 μM). The activity of the related enzyme AKR1A1 was left unaffected by all three compounds. This is the first time these three substances have been tested on AKRs. The results of this study may provide a basis for further quantitative structure?activity relationship models and promising scaffolds for future anti-diabetic or carcinopreventive drugs.

Selective Inhibition of Human AKR1B10 by n-Humulone, Adhumulone and Cohumulone Isolated from Humulus lupulus Extract

Hop-derived compounds have been subjected to numerous biomedical studies investigating their impact on a wide range of pathologies. Isomerised bitter acids (isoadhumulone, isocohumulone and isohumulone) from hops, used in the brewing process of beer, are known to inhibit members of the aldo-keto-reductase superfamily. Aldo-keto-reductase 1B10 (AKR1B10) is upregulated in various types of cancer and has been reported to promote carcinogenesis. Inhibition of AKR1B10 appears to be an attractive means to specifically treat RAS-dependent malignancies. However, the closely related reductases AKR1A1 and AKR1B1, which fulfil important roles in the detoxification of endogenous and xenobiotic carbonyl compounds oftentimes crossreact with inhibitors designed to target AKR1B10. Accordingly, there is an ongoing search for selective AKR1B10 inhibitors that do not interact with endogeneous AKR1A1 and AKR1B1-driven detoxification systems. In this study, unisomerised α-acids (adhumulone, cohumulone and n-humulone) were separated and tested for their inhibitory potential on AKR1A1, AKR1B1 and AKR1B10. Also AKR1B10-mediated farnesal reduction was effectively inhibited by α-acid congeners with Ki-values ranging from 16.79 ± 1.33 µM (adhumulone) to 3.94 ± 0.33 µM (n-humulone). Overall, α-acids showed a strong inhibition with selectivity (115⁻137 fold) for AKR1B10. The results presented herein characterise hop-derived α-acids as a promising basis for the development of novel and selective AKR1B10-inhibitors.

Immunohistochemistry Detects Increased Expression of Aldo-Keto Reductase Family 1 Member B10 (AKR1B10) in Early-Stage Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) remains difficult to diagnose at an early stage. Aldo-keto reductase family 1 member B10 (AKR1B10) is an oxidoreductase that is upregulated in some chronic liver diseases. The aim of this study was to use immunohistochemistry to evaluate the expression of AKR1B10 in liver tissue from patients with HCC of different stages.

Material/Methods

Forty-four patients with a tissue diagnosis of HCC (35 males and 9 females) with 37 control samples of liver tissue containing liver cirrhosis were studied using immunohistochemistry for the expression of AKR1B10. Histological examination determined the grade of HCC; the stage of HCC was determined according to the Barcelona Clinic Liver Cancer (BCLC) staging system. Serum alpha-fetoprotein (AFP) levels were measured and compared between the patients with HCC.

Results

Immunohistochemistry showed increased expression of AKR1B10 in moderately-differentiated HCC compared with well-differentiated HCC, poorly-differentiated HCC, and liver cirrhosis (P<0.05). Sensitivity and specificity of AKR1B10 expression in HCC were high at a cutoff integral optical density (IOD) value of 89.5. A significant increase in AKR1B10 expression was found in early-stage HCC (P<0.05). Serum AFP levels were increased in patients with poorly-differentiated HCC, were increased in intermediate-stage HCC, and were significantly increased in advanced-stage HCC (P<0.05).

Conclusions

Immunohistochemistry showed that the expression of AKR1B10 was increased in tumor tissue from patients with early-stage HCC. Further studies are needed to determine the role of AKR1B10 in the early detection of HCC.

Identification of a role for serum aldo-keto reductase family 1 member B10 in early detection of hepatocellular carcinoma

Despite improved screening programs, the vast majority of patients with hepatocellular carcinoma (HCC) are diagnosed at an advanced stage. A lack of effective diagnosis methods for preclinical HCC has resulted in a low rate of early detection. Aldo-keto reductase family 1 member B10 (AKR1B10) is associated with several cancer types. However, to the best of our knowledge, the diagnostic value of AKR1B10 in early stage HCC is poorly understood. In the current study, the diagnostic performance of serum AKR1B10 in hepatitis B virus/hepatitis C virus (HBV/HCV)-related liver disorders was evaluated and the unique role of AKR1B10 in diagnosing HCC was assessed. Serum AKR1B10 was detected by sandwich ELISA in 84 patients with HBV/HCV-related HCC, 74 patients with liver cirrhosis, 29 patients with chronic hepatitis and 30 healthy controls. Serum AKR1B10 and α-fetoprotein (AFP) levels were analyzed and compared. Elevated levels of serum AKR1B10 were identified in patients with HCC compared with patients with other liver disorders (P<0.05). Compared with advanced and terminal stage HCC, a significant increase in AKR1B10 levels was primarily detected in early and intermediate stage HCC. The sensitivity (81.0%) and specificity (60.9%) for HCC diagnosis with AKR1B10 were high at a cutoff value of 1.51 ng/ml. Conversely, a prominent increase in AFP was observed in advanced and terminal stage HCC. Furthermore, concurrent measurement of serum AKR1B10 and AFP significantly increased sensitivity and negative predictive value for HCC diagnosis. The results presented in the current study strongly indicate AKR1B10 has a unique role as a biomarker for early stage HBV/HCV-related HCC. Compared with AFP alone, a combination of serum AKR1B10 and AFP increased the diagnostic performance in patients with HCC. In summary, the current results identify a unique role of AKR1B10 in HCC diagnosis.

HCCDB: A Database of Hepatocellular Carcinoma Expression Atlas

Hepatocellular carcinoma (HCC) is highly heterogeneous in nature and has been one of the most common cancer types worldwide. To ensure repeatability of identified gene expression patterns and comprehensively annotate the transcriptomes of HCC, we carefully curated 15 public HCC expression datasets that cover around 4000 clinical samples and developed the database HCCDB to serve as a one-stop online resource for exploring HCC gene expression with user-friendly interfaces. The global differential gene expression landscape of HCC was established by analyzing the consistently differentially expressed genes across multiple datasets. Moreover, a 4D metric was proposed to fully characterize the expression pattern of each gene by integrating data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx). To facilitate a comprehensive understanding of gene expression patterns in HCC, HCCDB also provides links to third-party databases on drug, proteomics, and literatures, and graphically displays the results from computational analyses, including differential expression analysis, tissue-specific and tumor-specific expression analysis, survival analysis, and co-expression analysis. HCCDB is freely accessible at http://lifeome.net/database/hccdb.

Potential of AKR1B10 as a Biomarker and Therapeutic Target in Type 2 Leprosy Reaction

The AKR1B10 (aldo-keto reductase family 1 member B10) gene has important functions in carcinogen-induced neoplasia. AKR1B10 is also expressed in type 2 reaction leprosy patients (R2). We measured the expression of AKR1B10 in the skin lesions of patients with leprosy by immunohistochemistry from biopsies that encompassed the spectrum of types of leprosy, based on the Ridley and Jopling classification [10 samples each of tuberculoid (TT), borderline tuberculoid (BT), mid-borderline (BB), and borderline lepromatous (BL) lesions; four samples of lepromatous lesions (LL)], reactional leprosy [14 samples of type 1 Reaction (R1) and 10 samples of type 2 Reaction (R2)], and biopsies from 9 healthy control (HC) subjects. In addition, 46 lepromatous lesions (BL and LL), 45 lepromatous lesions in regression, and 115 R2 lesions were included. Eight of 10 R2 samples (80%), 3 of 46 active BL and LL samples (6%), 23 of 45 BL and LL samples in regression (51%), and 107 of 115 R2 samples (93%) were positive for AKR1B10, differing significantly between all groups (p < 0.05). AKR1B10 expression was highest in the cytoplasm of macrophages. Thus, AKR1B10 is overexpressed on the lepromatous side (BL and LL) in samples that are in regression, especially type 2 reaction-associated lesions, rendering it a potential marker of type 2 reactional episodes of leprosy and a target of drugs against reactional episodes.

Integrated analysis of the impact of age on genetic and clinical aspects of hepatocellular carcinoma

Despite the rapid growing and aging of populations worldwide, our knowledge on hepatocellular carcinoma (HCC) is still age-standardized rather than age-specific, with only few studies exploring the topic from a genetic point of view. Here, we analyze clinical and genetic aspects of HCC in patients of different age groups with the major attention directed to children (≤20 y) and elderly groups (≥80 y). A number of significant differences were found in elderly patients compared to children group, including smaller tumor size (P=0.001) and improved survival rates (P=0.002). Differences in gene mutations, copy number variants, and mRNA expressions were identified between the groups, with alteration rates for some genes like AKR1B10 increasing significantly with the age of patients. Immunohistochemistry testing of AKR1B10 showed a significant difference in expression levels at the age of 40 (30.77% high expression rate in patients younger than 40 compared to 51.57% in older patients) (P=0.043). Expression levels also differed between HCC tissues (49.64%) and near-tumor tissues (6.58%) (P<0.001). These findings contribute to the limited data available regarding the age-specific aspects of HCC patients, and support the need to address potential differences in the diagnosis, treatment, and prevention strategies of HCC.

Biostatistics mining associated method identifies AKR1B10 enhancing hepatocellular carcinoma cell growth and degenerated by miR-383-5p

Previous studies have reported that the aberrantly expressed AKR1B10 is associated with many cancer development, however the functional roles of AKR1B10 and its regulatory mechanisms in hepatocellular carcinoma (HCC) have been limited studied. In this project, we identified AKR1B10 functional as an oncogene in HCC through tumor/normal human tissue comparison from both GEO microarray and TCGA RNAseq dataset. Further experimental validations from three HCC cell lines (SMMC-7721, HePG2 and HeP3B) also suggested the ontogenetic functions of AKR1B10 in HCC tumor growth. By knocking down AKR1B10 through shRNA in HCC HeP3B cells, we showed it significantly induced cell cycle arrest and inhibited cell growth. Interestingly, integrative analysis of TCGA RNAseq data and miRNA-seq data predicted that miR-383-5p, a novel post-transcriptional tumor suppressor, is negatively associated with AKR1B10 expression. To further investigate the role of miR-383-5p in regulating AKR1B10 in HCC, we performed Dual-luciferase reporter assay experiments. Results showed that miR-383-5p is an upstream modulator targeting AKR1B10 in the post-transcriptional stage. Thus, we report AKR1B10 modulated regulated by miR-383-5p, promotes HCC tumor progress, and could be potentially a therapeutic target for precision medicine in HCC.

Aldo-Keto Reductases as Early Biomarkers of Hepatocellular Carcinoma: A Comparison Between Animal Models and Human HCC

BACKGROUND

The intrinsic heterogeneity of hepatocellular carcinoma (HCC) represents a great challenge for its molecular classification and for detecting predictive biomarkers. Aldo-keto reductase (Akr) family members have shown differential expression in human HCC, while AKR1B10 overexpression is considered a biomarker; AKR7A3 expression is frequently reduced in HCC.

AIMS

To investigate the time-course expression of Akr members in the experimental hepatocarcinogenesis.

METHODS

Using DNA-microarray data, we analyzed the time-course gene expression profile from nodules to tumors (4-17 months) of 17 Akr members induced by the resistant hepatocyte carcinogenesis model in the rat.

RESULTS

The expression of six members (Akr1c19, Akr1b10, Akr7a3, Akr1b1, Akr1cl1, and Akr1b8) was increased, comparable to that of Ggt and Gstp1, two well-known liver cancer markers. In particular, Akr7a3 and Akr1b10 expression also showed a time-dependent increment at mRNA and protein levels in a second hepatocarcinogenesis model induced with diethylnitrosamine. We confirmed that aldo-keto reductases 7A3 and 1B10 were co-expressed in nine biopsies of human HCC, independently from the presence of glypican-3 and cytokeratin-19, two well-known HCC biomarkers. Because it has been suggested that expression of Akr members is regulated through NRF2 activity at the antioxidant response element (ARE) sequences, we searched and identified at least two ARE sites in Akr1b1, Akr1b10, and Akr7a3 from rat and human gene sequences. Moreover, we observed higher NRF2 nuclear translocation in tumors as compared with non-tumor tissues.

CONCLUSIONS

Our results demonstrate that Akr7a3 mRNA and protein levels are consistently co-expressed along with Akr1b10, in both experimental liver carcinogenesis and some human HCC samples. These results highlight the presence of AKR7A3 and AKR1B10 from early stages of the experimental HCC and introduce them as a potential application for early diagnosis, staging, and prognosis in human cancer.

Regulation and role of nuclear factor-E2-related factor 2 (Nrf2) in multidrug resistance of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) chemoresistance, which is regarded as a kind of stress management reaction to chemotherapy drugs, severely hinders the therapy outcomes of HCC treatment. Stress management is generally achieved by activating certain signal pathways and chemical factors, among which, nuclear factor-E2-related factor2 (Nrf2) is a key factor in HCC chemoresistance formation. Nrf2 is a nuclear factor that coordinates the induction and expression of a battery of genes encoding cytoprotective proteins when participating in the Nrf2antioxidant response element (Nrf2/ARE) pathway, which is one of the most important intracellular antioxidant stress pathways. This review summarizes the recent understanding of the involvement of Nrf2 in the chemoresistance of liver cancer, its target proteins, expression regulation and potential Nrf2 inhibitors that sensitize chemotherapy drugs in HCC.

Synthesis of Potent and Selective Inhibitors of Aldo-Keto Reductase 1B10 and Their Efficacy against Proliferation, Metastasis, and Cisplatin Resistance of Lung Cancer Cells

Aldo-keto reductase 1B10 (AKR1B10) is overexpressed in several extraintestinal cancers, particularly in non-small-cell lung cancer, where AKR1B10 is a potential diagnostic marker and therapeutic target. Selective AKR1B10 inhibitors are required because compounds should not inhibit the highly related aldose reductase that is involved in monosaccharide and prostaglandin metabolism. Currently, 7-hydroxy-2-(4-methoxyphenylimino)-2H-chromene-3-carboxylic acid benzylamide (HMPC) is known to be the most potent competitive inhibitor of AKR1B10, but it is nonselective. In this study, derivatives of HMPC were synthesized by removing the 4-methoxyphenylimino moiety and replacing the benzylamide with phenylpropylamide. Among them, 4c and 4e showed higher AKR1B10 inhibitory potency (IC₅₀ 4.2 and 3.5 nM, respectively) and selectivity than HMPC. The treatments with the two compounds significantly suppressed not only migration, proliferation, and metastasis of lung cancer A549 cells but also metastatic and invasive potentials of cisplatin-resistant A549 cells.

Genomic variants link to hepatitis C racial disparities

Chronic liver diseases are one of the major public health issues in United States, and there are substantial racial disparities in liver cancer-related mortality. We previously identified racially distinct alterations in the expression of transcripts and proteins of hepatitis C (HCV)-induced hepatocellular carcinoma (HCC) between Caucasian (CA) and African American (AA) subgroups. Here, we performed a comparative genome-wide analysis of normal vs. HCV+ (cirrhotic state), and normal adjacent tissues (HCCN) vs. HCV+HCC (tumor state) of CA at the gene and alternative splicing levels using Affymetrix Human Transcriptome Array (HTA2.0). Many genes and splice variants were abnormally expressed in HCV+ more than in HCV+HCC state compared with normal tissues. Known biological pathways related to cell cycle regulations were altered in HCV+HCC, whereas acute phase reactants were deregulated in HCV+ state. We confirmed by quantitative RT-PCR that SAA1, PCNA-AS1, DAB2, and IFI30 are differentially deregulated, especially in AA compared with CA samples. Likewise, IHC staining analysis revealed altered expression patterns of SAA1 and HNF4α isoforms in HCV+ liver samples of AA compared with CA. These results demonstrate that several splice variants are primarily deregulated in normal vs. HCV+ stage, which is certainly in line with the recent observations showing that the pre-mRNA splicing machinery may be profoundly remodeled during disease progression, and may, therefore, play a major role in HCV racial disparity. The confirmation that certain genes are deregulated in AA compared to CA tissues also suggests that there is a biological basis for the observed racial disparities.

Retrospective Proteomic Screening of 100 Breast Cancer Tissues

The present investigation has been conducted on one hundred tissue fragments of breast cancer, collected and immediately cryopreserved following the surgical resection. The specimens were selected from patients with invasive ductal carcinoma of the breast, the most frequent and potentially aggressive type of mammary cancer, with the objective to increase the knowledge of breast cancer molecular markers potentially useful for clinical applications. The proteomic screening; by 2D-IPG and mass spectrometry; allowed us to identify two main classes of protein clusters: proteins expressed ubiquitously at high levels in all patients; and proteins expressed sporadically among the same patients. Within the group of ubiquitous proteins, glycolytic enzymes and proteins with anti-apoptotic activity were predominant. Among the sporadic ones, proteins involved in cell motility, molecular chaperones and proteins involved in the detoxification appeared prevalent. The data of the present study indicates that the primary tumor growth is reasonably supported by concurrent events: the inhibition of apoptosis and stimulation of cellular proliferation, and the increased expression of glycolytic enzymes with multiple functions. The second phase of the evolution of the tumor can be prematurely scheduled by the occasional presence of proteins involved in cell motility and in the defenses of the oxidative stress. We suggest that this approach on large-scale 2D-IPG proteomics of breast cancer is currently a valid tool that offers the opportunity to evaluate on the same assay the presence and recurrence of individual proteins, their isoforms and short forms, to be proposed as prognostic indicators and susceptibility to metastasis in patients operated on for invasive ductal carcinoma of the breast.

Expression of AKR1B10 as an independent marker for poor prognosis in human oral squamous cell carcinoma

BACKGROUND

Aldo-keto reductase family 1 member B10 (AKR1B10) is implicated in xenobiotic detoxification and has disparate functions in tumorigenesis that are dependent on the cell types. The purpose of this study was to investigate the clinicopathological significance of AKR1B10 as a prognostic marker for oral squamous cell carcinomas (OSCCs).

METHODS

AKR1B10 protein expression was analyzed by immunohistochemistry in 77 patients with OSCC.

RESULTS

The AKR1B10 labeling score for OSCCs (1.16 ± 1.14) was significantly higher than that for normal oral mucosa (0.10 ± 0.23; p < .0001). High expression of AKR1B10 significantly correlated with large tumor size (p = .041), advanced TNM classification (p = .037), and patient's areca quid chewing habit (p = .025). Multivariate analysis revealed that high AKR1B10 labeling score >1.16 (hazard ratio, 3.647; p = .001) significantly correlated with mortality.

CONCLUSION

AKR1B10 overexpression is an independent poor prognostic biomarker for OSCC. AKR1B10 inhibitors may be promising in clinical trials against OSCC. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1327-1332, 2017.

High expression of AKR1B10 predicts low risk of early tumor recurrence in patients with hepatitis B virus-related hepatocellular carcinoma

To clarify the relationship between aldo-keto reductase family 1 member B10 (AKR1B10) expression and early hepatocellular carcinoma (HCC) recurrence, this study detected AKR1B10 expression in tumor and adjacent non-tumor tissues from 110 patients with hepatitis B virus (HBV)-related HCC underwent liver resection and analyzed its correlations with clinicopathological characteristics and prognosis of these patients. Detected by quantitative reverse transcription polymerase chain reaction, AKR1B10 mRNA expression showed significantly higher in HCC tissues than in adjacent non-tumor tissues, with a low level in normal liver tissues. Similar results was confirmed at the protein level using immunohistochemistry and Western blotting. High AKR1B10 expression was negatively correlated with serum alpha-fetoprotein level and positively correlated with HBV-DNA level. Patients with high AKR1B10 expression had significantly higher disease-free survival than those with low expression within 2 years after liver resection. Multivariate analysis also confirmed high AKR1B10 expression to be a predictor of low risk of early HCC recurrence. In addition, high AKR1B10 expression was found to be a favorable factor of overall survival. These results suggest that AKR1B10 is involved in HBV-related hepatocarcinogenesis, but its high expression could predict low risk of early tumor recurrence in patients with HBV-related HCC after liver resection.

Prognostic significance of AKR1B10 gene expression in hepatocellular carcinoma and surrounding non-tumorous liver tissue

When assessing outcome in hepatocellular carcinoma (HCC), it is important to consider prognostic factors in background non-tumorous liver tissue as well as in the tumor, since multiple occurrence is associated with background liver status such as hepatitis. The current study aimed to elucidate molecular prognostic predictors that have an association with HCC background non-tumorous tissue. Microarray expression profiling identified aldo-keto reductase family 1, member B10 (AKR1B10) as a putative non-tumorous prognostic factor, and AKR1B10 gene expression was investigated in 158 curatively resected HCC cases by reverse transcription-quantitative polymerase chain reaction. AKR1B10 expression (AKR1B10 value/GAPDH value × 1,000) was significantly higher in tumor tissue (median, 9.2200; range, 0.0003-611.0200; n=158) than in the corresponding non-tumorous tissue (median, 0.5461; range, 0.0018-69.0300; n=158) (P<0.001). When the samples were grouped according to AKR1B10 expression in tumor tissue relative to non-tumorous tissue, tumor<non-tumorous expression (n=26) significantly correlated with poor recurrence-free survival (P=0.0074) and overall survival (OS) (P<0.0001), and was an independent prognostic factor for OS (P=0.0011) in a multivariate analysis. The ratio of AKR1B10 messenger RNA levels in HCC and corresponding non-tumorous tissues may predict prognosis after curative hepatectomy, with low expression in HCC tissue relative to non-tumorous tissue indicative of poor prognosis.

Inhibition of aldo-keto reductase family 1 member B10 by unsaturated fatty acids

A human member of the aldo-keto reductase (AKR) superfamily, AKR1B10, is a cytosolic NADPH-dependent reductase toward various carbonyl compounds including reactive aldehydes, and is normally expressed in intestines. The enzyme is overexpressed in several extraintestinal cancers, and suggested as a potential target for cancer treatment. We found that saturated and cis-unsaturated fatty acids inhibit AKR1B10. Among the saturated fatty acids, myristic acid was the most potent, showing the IC₅₀ value of 4.2 μM cis-Unsaturated fatty acids inhibited AKR1B10 more potently, and linoleic, arachidonic, and docosahexaenoic acids showed the lowest IC₅₀ values of 1.1 μM. The inhibition by these fatty acids was reversible and kinetically competitive with respect to the substrate, showing the K_i values of 0.24-1.1 μM. These fatty acids, except for α-linoleic acid, were much less inhibitory to structurally similar aldose reductase. Site-directed mutagenesis study suggested that the fatty acids interact with several active site residues of AKR1B10, of which Gln114, Val301 and Gln303 are responsible for the inhibitory selectivity. Linoleic and arachidonic acids also effectively inhibited AKR1B10-mediated 4-oxo-2-nonenal metabolism in HCT-15 cells. Thus, the cis-unsaturated fatty acids may be used as an adjuvant therapy for treatment of cancers that up-regulate AKR1B10.

Clinical implication of Keap1 and phosphorylated Nrf2 expression in hepatocellular carcinoma

In this paper, variation tendency of phosphorylated Nrf2, as the activated form of native Nrf2, was studied in 107 primary hepatocellular carcinoma (HCC) specimens treated by curative hepatectomy. Moreover, the coexpression of oxidative stress markers Keap1 and pNrf2, and their association with pathological features were also evaluated based on those specimens. The results showed that preserved cytoplasmic Keap1 expression of cancer cells was observed in 59 HCCs, while reduced Keap1 expression was determined in remaining 48 ones. With regarding to nuclear pNrf2 expression, 75 HCCs were defined as high and the other 32 ones as low. There was a significant association between Keap1 and pNrf2 expression in HCCs. Higher pNrf2 expression was observed, at a more substantial proportion, in those specimens with reduced Keap1 expression, compared to those with preserved Keap1 expression. The subset with higher pNrf2 and reduced Keap1 expression was defined as pNrf2⁺ Keap1⁻. According to the analysis of prognosis, this subset was significantly associated with poor 5‐year overall survival and worse disease‐free survival in HCCs, indicating that pNrf2 and Keap1 were two‐functional biomolecules, not only the oxidative stress markers but also biomarkers for prognosis of HCCs.

The role of hepatocyte nuclear factor 4-alpha in perfluorooctanoic acid- and perfluorooctanesulfonic acid-induced hepatocellular dysfunction

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), chemicals present in a multitude of consumer products, are persistent organic pollutants. Both compounds induce hepatotoxic effects in rodents, including steatosis, hepatomegaly and liver cancer. The mechanisms of PFOA- and PFOS-induced hepatic dysfunction are not completely understood. We present evidence that PFOA and PFOS induce their hepatic effects via targeting hepatocyte nuclear factor 4-alpha (HNF4α). Human hepatocytes treated with PFOA and PFOS at a concentration relevant to occupational exposure caused a decrease in HNF4α protein without affecting HNF4α mRNA or causing cell death. RNA sequencing analysis combined with Ingenuity Pathway Analysis of global gene expression changes in human hepatocytes treated with PFOA or PFOS indicated alterations in the expression of genes involved in lipid metabolism and tumorigenesis, several of which are regulated by HNF4α. Further investigation of specific HNF4α target gene expression revealed that PFOA and PFOS could promote cellular dedifferentiation and increase cell proliferation by down regulating positive targets (differentiation genes such as CYP7A1) and inducing negative targets of HNF4α (pro-mitogenic genes such as CCND1). Furthermore, in silico docking simulations indicated that PFOA and PFOS could directly interact with HNF4α in a similar manner to endogenous fatty acids. Collectively, these results highlight HNF4α degradation as novel mechanism of PFOA and PFOS-mediated steatosis and tumorigenesis in human livers.

The Aldo-Keto Reductase AKR1B10 Is Up-Regulated in Keloid Epidermis, Implicating Retinoic Acid Pathway Dysregulation in the Pathogenesis of Keloid Disease

Keloid disease is a recurrent fibroproliferative cutaneous tumor of unknown pathogenesis for which clinical management remains unsatisfactory. To obtain new insights into hitherto underappreciated aspects of keloid pathobiology, we took a laser capture microdissection-based, whole-genome microarray analysis approach to identify distinct keloid disease-associated gene expression patterns within defined keloid regions. Identification of the aldo-keto reductase enzyme AKR1B10 as highly up-regulated in keloid epidermis suggested that an imbalance of retinoic acid metabolism is likely associated with keloid disease. Here, we show that AKR1B10 transfection into normal human keratinocytes reproduced the abnormal retinoic acid pathway expression pattern we had identified in keloid epidermis. Cotransfection of AKR1B10 with a luciferase reporter plasmid showed reduced retinoic acid response element activity, supporting the hypothesis of retinoic acid synthesis deficiency in keloid epidermis. Paracrine signals released by AKR1B10-overexpressing keratinocytes into conditioned medium resulted in up-regulation of transforming growth factor-β1, transforming growth factor-β2, and collagens I and III in both keloid and normal skin fibroblasts, mimicking the typical profibrotic keloid profile. Our study results suggest that insufficient retinoic acid synthesis by keloid epidermal keratinocytes may contribute to the pathogenesis of keloid disease. We refocus attention on the role of injured epithelium in keloid disease and identify AKR1B10 as a potential new target in future management of keloid disease.

Aldo-keto Reductase Family 1 Member B 10 Mediates Liver Cancer Cell Proliferation through Sphingosine-1-Phosphate

AKR1B10 is involved in hepatocarcinogenesis via modulation of fatty acid and lipid synthesis. AKR1B10 inhibition results in apoptosis of tumor cells whose lipids, especially phospholipids, were decreased by over 50%, suggesting involvement of phospholipids like sphingosine-1-phosphate (S1P) in AKR1B10's oncogenic function. Using a co-culture system, we found that co-culture of QSG-7701 (human hepatocyte) with HepG2 (hepatoma cell line) increases QSG-7701's proliferation, in which AKR1B10-S1P signaling plays a pivotal role. Consistent with previous findings, AKR1B10 mRNA and protein levels were higher in primary hepatocellular carcinoma (PHC) tissues than in peri-tumor tissues. Interestingly, the level of S1P was also higher in PHC tissues than in peri-tumor tissues. After analyzing the correlation between AKR1B10 mRNA expression in PHC tissues and the clinical data, we found that AKR1B10 mRNA expression was associated with serum alpha-fetoprotein (AFP), tumor-node-metastasis (TNM) stage, and lymph node metastasis, but not with other clinicopathologic variables. A higher AKR1B10 mRNA expression level is related to a shorter DFS (disease free survival) and OS (overall survival), serving as an independent predictor of DFS and OS in PHC patients with surgical resection.

Novel chemical scaffolds of the tumor marker AKR1B10 inhibitors discovered by 3D QSAR pharmacophore modeling

AIM

Recent evidence suggests that aldo-keto reductase family 1 B10 (AKR1B10) may be a potential diagnostic or prognostic marker of human tumors, and that AKR1B10 inhibitors offer a promising choice for treatment of many types of human cancers. The aim of this study was to identify novel chemical scaffolds of AKR1B10 inhibitors using in silico approaches.

METHODS

The 3D QSAR pharmacophore models were generated using HypoGen. A validated pharmacophore model was selected for virtual screening of 4 chemical databases. The best mapped compounds were assessed for their drug-like properties. The binding orientations of the resulting compounds were predicted by molecular docking. Density functional theory calculations were carried out using B3LYP. The stability of the protein-ligand complexes and the final binding modes of the hit compounds were analyzed using 10 ns molecular dynamics (MD) simulations.

RESULTS

The best pharmacophore model (Hypo 1) showed the highest correlation coefficient (0.979), lowest total cost (102.89) and least RMSD value (0.59). Hypo 1 consisted of one hydrogen-bond acceptor, one hydrogen-bond donor, one ring aromatic and one hydrophobic feature. This model was validated by Fischer's randomization and 40 test set compounds. Virtual screening of chemical databases and the docking studies resulted in 30 representative compounds. Frontier orbital analysis confirmed that only 3 compounds had sufficiently low energy band gaps. MD simulations revealed the binding modes of the 3 hit compounds: all of them showed a large number of hydrogen bonds and hydrophobic interactions with the active site and specificity pocket residues of AKR1B10.

CONCLUSION

Three compounds with new structural scaffolds have been identified, which have stronger binding affinities for AKR1B10 than known inhibitors.