High expression of aldo-keto reductase 1B10 is an independent predictor of favorable prognosis in patients with hepatocellular carcinoma

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.

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.

Serum AKR1B10 as an indicator of unfavorable survival of hepatocellular carcinoma

BACKGROUND AND AIMS

A large-scale multicenter study validated aldo-keto reductase 1B10 (AKR1B10) as a new serum marker of hepatocellular carcinoma (HCC). This study aimed to evaluate the prognostic value of serum AKR1B10 in HCC.

METHODS

273 naïve HCC patients enrolled for serum AKR1B10 tests were followed up for 2 years. Survival and clinical data were collected. Kaplan-Meier survival analysis and log-rank tests were used to estimate correlation of patient survival with serum AKR1B10. Univariate and multivariate COX regression analyses were used to evaluate the prognostic value of serum AKR1B10 level independently or in combination with other clinicopathological factors. α-fetoprotein (AFP) was analyzed in parallel for comparison.

RESULTS

Serum AKR1B10 associated with tumor stage (p = 0.012), size (p = 0.004), primary tumor number (p = 0.019), and Child-Pugh classification (p = 0.003). HCC patients with a high level of serum AKR1B10 (≥ 267.9 pg/ml) had median survival (MS) of 25 months (95% confidence interval [CI] 20.788-29.212) vs. MS of 34 months (CI 28.911-39.089) in patients with normal serum AKR1B10 (p < 0.001). Univariate and multivariate COX regression analyses showed that serum AKR1B10 level was an unfavorable prognostic marker of HCC independently (HR 1.830, 95% CI 1.312-2.552; p < 0.001) or in combination with other clinical factors (HR 1.883, 95% CI 1.264-2.806; p = 0.002), such as TNM stage, tumor size and portal invasion. In the same cohort of HCC patients, AFP exhibited prognostic value at a cut-off of 400 ng/ml, but not at 20 ng/ml and 200 ng/ml.

CONCLUSIONS

Serum AKR1B10 is a new prognostic marker of HCC, better than AFP.

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.

Fidarestat induces glycolysis of NK cells through decreasing AKR1B10 expression to inhibit hepatocellular carcinoma

The aldose reductase inhibitor Fidarestat has been noted to have efficacy in treating a variety of tumors. To define its role in hepatocellular carcinoma (HCC), we induced a HCC xenograft model in mice, which were treated with different doses of Fidarestat. The amounts of natural killer (NK) cells and related inflammatory factors were detected in the serum of the mice. Fidarestat inhibited HCC tumor growth and lung metastasis in vivo and increased NK cell number as well as levels of NK cell-related inflammatory factors in mouse serum. NK cells were then co-cultured with the HCC cell line in vitro to detect effects on HCC cell progression after Fidarestat administration. The glycolysis activity of the NK cells was evaluated by extracellular acidification rate, while aldo-keto reductase family 1 member B10 (AKR1B10) expression was detected by western blot analysis. Administration of Fidarestat downregulated the expression of AKR1B10 in NK cells and promoted NK cell glycolysis to enhance their killing activity against HCC cells. However, depletion of NK cells or upregulation of AKR1B10 attenuated the anticancer activity of Fidarestat. Taken together, Fidarestat downregulated AKR1B10 expression in NK cells to promote NK cell glycolysis, thereby alleviating HCC progression.

Prognostic value of aldo-keto reductase family 1 member B10 (AKR1B10) in digestive system cancers: A meta-analysis

BACKGROUND

Numbers of studies have reported that the expression of aldo-keto reductase family 1 member B10 (AKR1B10) is abnormal in digestive system cancers, and could be used as a prognostic biomarker. However, the results are argued. Therefore, we conduct a meta-analysis to comprehensively evaluate the prognostic value of high AKR1B10 expression for overall survival (OS), disease specific survival (DSS), and disease-free survival/recurrence-free survival (DFS/PFS) in digestive system cancers.

METHODS

Hazard ratios (HRs) with its 95% confidence intervals (CIs) were calculated to assess the prognostic value of AKR1B10 by using the random effects model. The STATA version 12.0 software were used to perform all the analyses.

RESULTS

Eleven articles including 1428 patients involved in this meta-analysis. The pooled analysis suggested that high AKR1B10 expression was not associated with OS (HR: 1.18; 95% CI: 0.69-2.00) and DFS/PFS (HR: 1.08, 95% CI: 0.67-1.76) in digestive system cancers. However, Further analysis revealed that high AKR1B10 expression indicated poor OS in oral squamous cell carcinomas (OSCC) (HR: 2.92, 95% CI: 1.86-4.58) and favorable DSS in hepatocellular carcinoma (HCC) (HR: 0.71, 95% CI: 0.52-0.97).

CONCLUSIONS

The prognostic value of high AKR1B10 expression varied in different types of digestive system cancers. Further studies exploring the prognostic role of AKR1B10 in digestive system cancers are needed.

Aldo Keto Reductases AKR1B1 and AKR1B10 in Cancer: Molecular Mechanisms and Signaling Networks

Deregulation of metabolic pathways has increasingly been appreciated as a major driver of cancer in recent years. The principal cancer-associated alterations in metabolism include abnormal uptake of glucose and amino acids and the preferential use of metabolic pathways for the production of biomass and nicotinamide adenine dinucleotide phosphate (NADPH). Aldo-keto reductases (AKRs) are NADPH dependent cytosolic enzymes that can catalyze the reduction of carbonyl groups to primary and secondary alcohols using electrons from NADPH. Aldose reductase, also known as AKR1B1, catalyzes the conversion of excess glucose to sorbitol and has been studied extensively for its role in a number of diabetic pathologies. In recent years, however, high expression of the AKR1B and AKR1C family of enzymes has been strongly associated with worse outcomes in different cancer types. This review provides an overview of the catalysis-dependent and independent data emerging on the molecular mechanisms of the functions of AKRBs in different tumor models with an emphasis of the role of these enzymes in chemoresistance, inflammation, oxidative stress and epithelial-to-mesenchymal transition.

Bioinformatic profiling identifies a platinum-resistant-related risk signature for ovarian cancer

Most high-grade serous ovarian cancer (HGSOC) patients develop resistance to platinum-based chemotherapy and recur. Many biomarkers related to the survival and prognosis of drug-resistant patients have been delved by mining databases; however, the prediction effect of single-gene biomarker is not specific and sensitive enough. The present study aimed to develop a novel prognostic gene signature of platinum-based resistance for patients with HGSOC. The gene expression profiles were obtained from Gene Expression Omnibus and The Cancer Genome Atlas database. A total of 269 differentially expressed genes (DEGs) associated with platinum resistance were identified (P < .05, fold change >1.5). Functional analysis revealed that these DEGs were mainly involved in apoptosis process, PI3K-Akt pathway. Furthermore, we established a set of seven-gene signature that was significantly associated with overall survival (OS) in the test series. Compared with the low-risk score group, patients with a high-risk score suffered poorer OS (P < .001). The area under the curve (AUC) was found to be 0.710, which means the risk score had a certain accuracy on predicting OS in HGSOC (AUC > 0.7). Surprisingly, the risk score was identified as an independent prognostic indicator for HGSOC (P < .001). Subgroup analyses suggested that the risk score had a greater prognostic value for patients with grade 3-4, stage III-IV, venous invasion and objective response. In conclusion, we developed a seven-gene signature relating to platinum resistance, which can predict survival for HGSOC and provide novel insights into understanding of platinum resistance mechanisms and identification of HGSOC patients with poor prognosis.

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.

Characterizing methylation regulated miRNA in carcinoma of the human uterine cervix

Gene regulatory mechanisms determine the multistep carcinogenesis process. Two aspects of epigenetics are microRNA (miRNAs) and DNA methylation that regulate distinct biological mechanisms such as metastasis, apoptosis cell proliferation and induction of senescence. Although critical, the interplay between these two epigenetic mechanisms is yet to be completely understood, particularly in cervical cancer. To study the DNA methylation regulation of miRNAs and its potential role in cervical cancer, we investigated the differential methylation pattern of two candidate miRNAs (miR-375 and miR-196a-1) during cervical cancer progression against normal cervical epithelium (NCE) by bisulfite DNA sequencing. miR-375 and miR-196a-1 were hypermethylated in Squamous Cell Carcinoma (SCC) against NCE and Cervical Intra-Epithelial Neoplasia (CIN) (p < 0.05). Treatment with demethylating agent reactivated the miR-375 and miR-196a-1 expression in SiHa, HeLa and CaSki cells. In vitro artificial methylation by M.SssI followed by dual luciferase assay confirmed miR-375 and miR-196a-1 as methylation regulated miRNAs (P < 0.05). miR-375 and miR-196a-1 expression levels were negatively correlated with methylation levels in clinical specimens. We further identified Replication Factor C Subunit 3 (RFC3) and High Mobility Group AT-Hook 1 (HMGA1) as targets of miR-375 and miR-196a-1 respectively by dual luciferase reporter assay. Our analysis indicates that miR-375 and miR-196a-1 are DNA methylation regulated miRNAs whose deregulation may facilitate pathophysiology of cervical cancer.

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.

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.

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.

Mammalian Sulfur Amino Acid Metabolism: A Nexus Between Redox Regulation, Nutrition, Epigenetics, and Detoxification

SIGNIFICANCE

Transsulfuration allows conversion of methionine into cysteine using homocysteine (Hcy) as an intermediate. This pathway produces S-adenosylmethionine (AdoMet), a key metabolite for cell function, and provides 50% of the cysteine needed for hepatic glutathione synthesis. The route requires the intake of essential nutrients (e.g., methionine and vitamins) and is regulated by their availability. Transsulfuration presents multiple interconnections with epigenetics, adenosine triphosphate (ATP), and glutathione synthesis, polyol and pentose phosphate pathways, and detoxification that rely mostly in the exchange of substrates or products. Major hepatic diseases, rare diseases, and sensorineural disorders, among others that concur with oxidative stress, present impaired transsulfuration. Recent Advances: In contrast to the classical view, a nuclear branch of the pathway, potentiated under oxidative stress, is emerging. Several transsulfuration proteins regulate gene expression, suggesting moonlighting activities. In addition, abnormalities in Hcy metabolism link nutrition and hearing loss.

CRITICAL ISSUES

Knowledge about the crossregulation between pathways is mostly limited to the hepatic availability/removal of substrates and inhibitors. However, advances regarding protein-protein interactions involving oncogenes, identification of several post-translational modifications (PTMs), and putative moonlighting activities expand the potential impact of transsulfuration beyond methylations and Hcy.

FUTURE DIRECTIONS

Increasing the knowledge on transsulfuration outside the liver, understanding the protein-protein interaction networks involving these enzymes, the functional role of their PTMs, or the mechanisms controlling their nucleocytoplasmic shuttling may provide further insights into the pathophysiological implications of this pathway, allowing design of new therapeutic interventions. Antioxid. Redox Signal. 29, 408-452.

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.

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.

Aldose reductase interacts with AKT1 to augment hepatic AKT/mTOR signaling and promote hepatocarcinogenesis

Marked up-regulation of aldose reductase (AR) is reportedly associated with the development of hepatocellular carcinoma (HCC). We investigated how aberrantly overexpressed AR might promote oncogenic transformation in liver cells and tissues. We found that overexpressed AR interacted with the kinase domain of AKT1 to increase AKT/mTOR signaling. In both cultured liver cancer cells and liver tissues in DEN-induced transgenic HCC model mice, we observed that AR overexpression-induced AKT/mTOR signaling tended to enhance lactate formation and hepatic inflammation to enhance hepatocarcinogenesis. Conversely, AR knockdown suppressed lactate formation and inflammation. Using cultured liver cancer cells, we also demonstrated that AKT1 was essential for AR-induced dysregulation of AKT/mTOR signaling, metabolic reprogramming, antioxidant defense, and inflammatory responses. These findings suggest that aberrantly overexpressed/over-activated hepatic AR promotes HCC development at least in part by interacting with oncogenic AKT1 to augment AKT/mTOR signaling. Inhibition of AR and/or AKT1 might serve as an effective strategy for the prevention and therapy of liver cancer.

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.

Aldo-Keto Reductase Family 1 Member B10 Inhibitors: Potential Drugs for Cancer Treatment

Cytosolic NADPH-dependent reductase AKR1B10 is a member of the aldo-keto reductase (AKR) superfamily. This enzyme is normally expressed in the gastrointestinal tract. However, it is overexpressed in many solid tumors, such as hepatocarcinoma, lung cancer and breast cancer. AKR1B10 may play a role in the formation and development of carcinomas through multiple mechanisms including detoxification of cytotoxic carbonyls, modulation of retinoic acid level, and regulation of cellular fatty acid synthesis and lipid metabolism. Studies have suggested that AKR1B10 may be a useful biomarker for cancer diagnosis and a potential target for cancer treatment. Over the last decade, a number of AKR1B10 inhibitors including aldose reductase inhibitors (ARIs), endogenous substances, natural-based derivatives and synthetic compounds have been developed, which could be novel anticancer drugs. This review provides an overview on related articles and patents about AKR1B10 inhibitors, with a focus on their inhibition selectivity and mechanism of function.

Regulation of aldo-keto-reductase family 1 B10 by 14-3-3ε and their prognostic impact of hepatocellular carcinoma

14-3-3ε is overexpressed in hepatocellular carcinoma (HCC) and its expression significantly associates with a poor prognostic outcome. To uncover how 14-3-3ε contributes to the tumor progression of HCC, we investigated the potential downstream targets regulated by 14-3-3ε. We found that 14-3-3ε increases expression and nuclear translocation of β-catenin and that 14-3-3ε-induced cell proliferation is attenuated by β-catenin silencing in HCC cells. Moreover, 14-3-3ε induces aldo-keto reductase family 1 member B10 (AKR1B10) expression through the activation of β-catenin signaling. Knockdown of AKR1B10 by siRNAs abolished 14-3-3ε-induced in vitro cell proliferation, anchorage-independent growth as well as in vivo tumor growth. Furthermore, AKR1B10 silencing increased retinoic acid (RA) levels in the serum of tumor-bearing mice and RA treatment attenuated 14-3-3ε-induced HCC cell proliferation. We further examined 14-3-3ε and AKR1B10 expression and clinicopathological characteristics of HCC tumors. Although the expression of AKR1B10 was significantly correlated with 14-3-3ε, an increase of AKR1B10 expression in 14-3-3ε positive patients paradoxically had better overall survival and disease-free survival rates as well as lower metastatic incidence than those without an AKR1B10 increase. Finally, we found a loss of AKR1B10 expression in cells exhibiting a high capacity of invasiveness. Silencing of AKR1B10 resulted in inducing snail and vimentin expression in HCC cells. These results indicate that AKR1B10 may play a dual role during HCC tumor progression. Our results also indicate that 14-3-3ε regulates AKR1B10 expression by activating β-catenin signaling. A combination of 14-3-3ε with AKR1B10 is a potential therapeutic target and novel prognostic biomarker of HCC.

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.

Flavones Inhibit the Activity of AKR1B10, a Promising Therapeutic Target for Cancer Treatment

AKR1B10 is an NADPH-dependent reductase that plays an important function in several physiological reactions such as the conversion of retinal to retinol, reduction of isoprenyl aldehydes, and biotransformation of procarcinogens and drugs. A growing body of evidence points to the important role of the enzyme in the development of several types of cancer (e.g., breast, hepatocellular), in which it is highly overexpressed. AKR1B10 is regarded as a therapeutic target for the treatment of these diseases, and potent and specific inhibitors may be promising therapeutic agents. Several inhibitors of AKR1B10 have been described, but the area of natural plant products has been investigated sparingly. In the present study almost 40 diverse phenolic compounds and alkaloids were examined for their ability to inhibit the recombinant AKR1B10 enzyme. The most potent inhibitors-apigenin, luteolin, and 7-hydroxyflavone-were further characterized in terms of IC50, selectivity, and mode of action. Molecular docking studies were also conducted, which identified putative binding residues important for the interaction. In addition, cellular studies demonstrated a significant inhibition of the AKR1B10-mediated reduction of daunorubicin in intact cells by these inhibitors without a considerable cytotoxic effect. Although these compounds are moderately potent and selective inhibitors of AKR1B10, they constitute a new structural type of AKR1B10 inhibitor and may serve as a template for the development of better inhibitors.