Expression of the Aldo-Ketoreductases AKR1B1 and AKR1B10 in Human Cancers

A Multi-Omics Study of Epigenetic Changes in Type II Alveolar Cells of A/J Mice Exposed to Environmental Tobacco Smoke

Lung cancer remains a major contributor to cancer fatalities, with cigarette smoking known to be responsible for up to 80% of cases. Based on the ability of cigarette smoke to induce inflammation in the lungs and increased lung cancer incidence in smokers with inflammatory conditions such as COPD, we hypothesized that inflammation plays an important role in the carcinogenicity of cigarette smoke. To test this hypothesis, we performed multi-omic analyses of Type II pneumocytes of A/J mice exposed to cigarette smoke for various time periods. We found that cigarette smoke exposure resulted in significant changes in DNA methylation and hydroxymethylation, gene expression patterns, and protein abundance that were partially reversible and contributed to an inflammatory and potentially oncogenic phenotype.

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 New Histology-Based Prognostic Index for Aggressive T-Cell lymphoma: Preliminary Results of the "TCL Urayasu Classification"

Background: Aggressive mature T-cell lymphoma (TCL) is a disease that carries a poor prognosis. Methods: We analyzed the expression of 22 tumor cell functional proteins in 16 randomly selected patients with TCL. Immunohistochemistry was performed in paraffin-embedded tumor tissue sections to determine the protein expression statuses in tumor cells. Results: Glucose-regulated protein 94 (GRP94), a protein that serves as a pro-survival component under endoplasmic reticulum (ER) stress in the tumor microenvironment, was significantly associated with a shortened survival. Furthermore, significant differences were observed when GRP94 was combined with six other factors. The six factors were (1) programmed cell death-ligand 1 (PD-L1); (2) programmed cell death 1 (PD-1); (3) aldo-keto reductase family 1 member C3 (AKR1C3); (4) P53, a tumor suppressor; (5) glucose-regulated protein 78 (GRP78), an ER stress protein; and (6) thymidine phosphorylase (TP). Based on the combination of GRP94 and the six other factors expressed in the tumors, we propose a new prognostic classification system for TCL (TCL Urayasu classification). Group 1 (relatively good prognosis): GRP94-negative (n = 6; median OS, 88 months; p < 0.01); Group 2 (poor prognosis): GRP94-positive, plus expression of two of the six factors mentioned above (n = 5; median OS, 25 months; p > 0.05); and Group 3 (very poor prognosis): GRP94-positive, plus expression of at least three of the six factors mentioned above (n = 5; median OS, 10 months; p < 0.01). Conclusions: Thus, the TCL Urayasu prognostic classification may be a simple, useful, and innovative classification that also explains the mechanism of resistance to treatment for each functional protein. If validated in a larger number of patients, the TCL Urayasu classification will enable a targeted treatment using selected inhibitors acting on the abnormal protein found in each patient.

Nicotinate-curcumin improves NASH by inhibiting the AKR1B10/ACCα-mediated triglyceride synthesis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a prevalent chronic liver condition. However, the potential therapeutic benefits and underlying mechanism of nicotinate-curcumin (NC) in the treatment of NASH remain uncertain.

METHODS

A rat model of NASH induced by a high-fat and high-fructose diet was treated with nicotinate-curcumin (NC, 20, 40 mg·kg- 1), curcumin (Cur, 40 mg·kg- 1) and metformin (Met, 50 mg·kg- 1) for a duration of 4 weeks. The interaction between NASH, Cur and Aldo-Keto reductase family 1 member B10 (AKR1B10) was filter and analyzed using network pharmacology. The interaction of Cur, NC and AKR1B10 was analyzed using molecular docking techniques, and the binding energy of Cur and NC with AKR1B10 was compared. HepG2 cells were induced by Ox-LDL (25 µg·ml- 1, 24 h) in high glucose medium. NC (20µM, 40µM), Cur (40µM) Met (150µM) and epalrestat (Epa, 75µM) were administered individually. The activities of ALT, AST, ALP and the levels of LDL, HDL, TG, TC and FFA in serum were quantified using a chemiluminescence assay. Based on the changes in the above indicators, score according to NAS standards. The activities of Acetyl-CoA and Malonyl-CoA were measured using an ELISA assay. And the expression and cellular localization of AKR1B10 and Acetyl-CoA carboxylase (ACCα) in HepG2 cells were detected by Western blotting and immunofluorescence.

RESULTS

The results of the animal experiments demonstrated that NASH rat model induced by a high-fat and high-fructose diet exhibited pronounced dysfunction in liver function and lipid metabolism. Additionally, there was a significant increase in serum levels of FFA and TG, as well as elevated expression of AKR1B10 and ACCα, and heightened activity of Acetyl-CoA and Malonyl-CoA in liver tissue. The administration of NC showed to enhance liver function in rats with NASH, leading to reductions in ALT, AST and ALP levels, and decrease in blood lipid and significant inhibition of FFA and TG synthesis in the liver. Network pharmacological analysis identified AKR1B10 and ACCα as potential targets for NASH treatment. Molecular docking studies revealed that both Cur and NC are capable of binding to AKR1B10, with NC exhibiting a stronger binding energy to AKR1B10. Western blot analysis demonstrated an upregulation in the expression of AKR1B10 and ACCα in the liver tissue of NASH rats, accompanied by elevated Acetyl-CoA and Malonyl-CoA activity, and increased levels of FFA and TG. The results of the HepG2 cell experiments induced by Ox-LDL suggest that NC significantly inhibited the expression and co-localization of AKR1B10 and ACCα, while also reduced levels of TC and LDL-C and increased level of HDL-C. These effects are accompanied by a decrease in the activities of ACCα and Malonyl-CoA, and levels of FFA and TG. Furthermore, the impact of NC appears to be more pronounced compared to Cur.

CONCLUSION

NC could effectively treat NASH and improve liver function and lipid metabolism disorder. The mechanism of NC is related to the inhibition of AKR1B10/ACCα pathway and FFA/TG synthesis of liver.

Development of a prognostic model for muscle-invasive bladder cancer using glutamine metabolism

BACKGROUND

Muscle-invasive bladder cancer (MIBC) is distinguished by its pronounced invasiveness and unfavorable prognosis. Immunotherapy and targeted therapy have emerged as key treatment options for various types of cancer. Altered metabolism is a defining characteristic of cancer cells, and there is mounting evidence suggesting the important role of glutamine metabolism (GM) in tumor metabolism. Nevertheless, the relationship between GM and clinical outcomes, immune microenvironment, and immunotherapy in MIBC remains unknown.

METHODS

This study employed Mendelian randomization to explore the causal relationship between blood metabolites and bladder tumors. We systematically evaluated 373 glutamine metabolism-related genes and identified prognostic-related genes, leading to the construction of a glutamine-associated prognostic model. Further analysis confirmed the correlation between high and low-risk groups with the tumor microenvironment, immune cell infiltration, and tumor mutation burden. Subsequently, we assessed the relationship between the risk score and the sensitivity to various immunotherapies and anticancer drugs.

RESULTS

We identified 14 blood metabolites at the molecular level that have a causal relationship with bladder tumors. At the gene level, the study discussed differentially expressed GM genes in MIBC. First, we established a risk model predicting overall survival (OS) based on GM genes, confirming its reliable predictive ability in MIBC patients and validated it in a GEO cohort. Additionally, a reliable column line chart was created. Secondly, two distinct molecular subtypes were identified, and the associations between different risk groups and tumor microenvironment and immune infiltration were observed. In addition, the predicted risk values correlated with responses to a broad range of pharmaceutical agents.

CONCLUSION

In summary, we confirmed the causal relationship between blood metabolites and bladder tumors. Furthermore, a risk scoring model related to glutamine metabolism consisting of 9 genes was developed. This model could potentially serve as a useful tool for predicting prognosis and guiding the treatment of MIBC patients.

The polyol pathway and nuclear ketohexokinase A signaling drive hyperglycemia-induced metastasis of gastric cancer

Diabetes might be associated with increased cancer risk, with several studies reporting hyperglycemia as a primary oncogenic stimulant. Since glucose metabolism is linked to numerous metabolic pathways, it is difficult to specify the mechanisms underlying hyperglycemia-induced cancer progression. Here, we focused on the polyol pathway, which is dramatically activated under hyperglycemia and causes diabetic complications. We investigated whether polyol pathway-derived fructose facilitates hyperglycemia-induced gastric cancer metastasis. We performed bioinformatics analysis of gastric cancer datasets and immunohistochemical analyses of gastric cancer specimens, followed by transcriptomic and proteomic analyses to evaluate phenotypic changes in gastric cancer cells. Consequently, we found a clinical association between the polyol pathway and gastric cancer progression. In gastric cancer cell lines, hyperglycemia enhanced cell migration and invasion, cytoskeletal rearrangement, and epithelial-mesenchymal transition (EMT). The hyperglycemia-induced acquisition of metastatic potential was mediated by increased fructose derived from the polyol pathway, which stimulated the nuclear ketohexokinase-A (KHK-A) signaling pathway, thereby inducing EMT by repressing the CDH1 gene. In two different xenograft models of cancer metastasis, gastric cancers overexpressing AKR1B1 were found to be highly metastatic in diabetic mice, but these effects of AKR1B1 were attenuated by KHK-A knockdown. In conclusion, hyperglycemia induces fructose formation through the polyol pathway, which in turn stimulates the KHK-A signaling pathway, driving gastric cancer metastasis by inducing EMT. Thus, the polyol and KHK-A signaling pathways could be potential therapeutic targets to decrease the metastatic risk in gastric cancer patients with diabetes.

Tumor microenvironment deconvolution identifies cell-type-independent aberrant DNA methylation and gene expression in prostate cancer

BACKGROUND

Among men, prostate cancer (PCa) is the second most common cancer and the second leading cause of cancer death. Etiologic factors associated with both prostate carcinogenesis and somatic alterations in tumors are incompletely understood. While genetic variants associated with PCa have been identified, epigenetic alterations in PCa are relatively understudied. To date, DNA methylation (DNAm) and gene expression (GE) in PCa have been investigated; however, these studies did not correct for cell-type proportions of the tumor microenvironment (TME), which could confound results.

METHODS

The data (GSE183040) consisted of DNAm and GE data from both tumor and adjacent non-tumor prostate tissue of 56 patients who underwent radical prostatectomies prior to any treatment. This study builds upon previous studies that examined methylation patterns and GE in PCa patients by using a novel tumor deconvolution approach to identify and correct for cell-type proportions of the TME in its epigenome-wide association study (EWAS) and differential expression analysis (DEA).

RESULTS

The inclusion of cell-type proportions in EWASs and DEAs reduced the scope of significant alterations associated with PCa. We identified 2,093 significantly differentially methylated CpGs (DMC), and 51 genes associated with PCa, including PCA3, SPINK1, and AMACR.

CONCLUSIONS

This work illustrates the importance of correcting for cell types of the TME when performing EWASs and DEAs on PCa samples, and establishes a more confounding-adverse methodology. We identified a more tumor-cell-specific set of altered genes and epigenetic marks that can be further investigated as potential biomarkers of disease or potential therapeutic targets.

A comprehensive computational approach for the identification of structure-based potential pharmacological candidates as selective AKR1B1 and AKR1B10 inhibitors: repurposing of purine alkaloids for the treatment of cancer

Significant metabolic pathways have been linked to AKR1B1 and AKR1B10. These enzymes are crucial biological targets in the therapy of colon cancer. In the past several decades, drug repurposing has gained appeal as a time and cost-efficient strategy for providing new indications for existing drugs. The structural properties of the plant-based alkaloidal drugs theobromine and theophylline were examined using density functional theory (DFT) computations, where the B3LYP/SVP method was used to quantify the dipole moment, polarizability, and optimization energy. Optimized structures obtained through DFT studies were docked inside the active pocket of target proteins to evaluate their inhibitory potential. Moreover, molecular dynamic simulation provides significant insight into a dynamic view of molecular interactions. The findings of current revealed theobromine and theophylline as strong AKR1B1 and AKR1B10 inhibitors, respectively. In addition, the anti-cancer potential of theophylline and theobromine was validated by targeting various tumor proteins, i.e. NF-κB, cellular tumor antigen P53 and caspase-3 using a molecular docking approach. Theobromine was found to be strongly interacted with NF-κB and caspase-3, whereas theophylline potentially inhibited cellular tumor antigen P53. In addition, the ADMET characteristics of theobromine and theophylline were identified, confirming their drug-like capabilities. These results should open the way for further experimental validation and structure-based drug design/repurposing of AKR1B1/AKR1B10 inhibitors for the treatment of colon cancer and associated malignancies.Communicated by Ramaswamy H. Sarma.

AKR1B1 Represses Glioma Cell Proliferation through p38 MAPK-Mediated Bcl-2/BAX/Caspase-3 Apoptotic Signaling Pathways

This study aimed to investigate the regulatory role of Aldo-keto reductase family 1 member B1 (AKR1B1) in glioma cell proliferation through p38 MAPK activation to control Bcl-2/BAX/caspase-3 apoptosis signaling. AKR1B1 expression was quantified in normal human astrocytes, glioblastoma multiforme (GBM) cell lines, and normal tissues by using quantitative real-time polymerase chain reaction. The effects of AKR1B1 overexpression or knockdown and those of AKR1B1-induced p38 MAPK phosphorylation and a p38 MAPK inhibitor (SB203580) on glioma cell proliferation were determined using an MTT assay and Western blot, respectively. Furthermore, the AKR1B1 effect on BAX and Bcl-2 expression was examined in real-time by Western blot. A luminescence detection reagent was also utilized to identify the effect of AKR1B1 on caspase-3/7 activity. The early and late stages of AKR1B1-induced apoptosis were assessed by performing Annexin V-FITC/PI double-staining assays. AKR1B1 expression was significantly downregulated in glioma tissues and GBM cell lines (T98G and 8401). Glioma cell proliferation was inhibited by AKR1B1 overexpression but was slightly increased by AKR1B1 knockdown. Additionally, AKR1B1-induced p38 MAPK phosphorylation and SB203580 reversed AKR1B1's inhibitory effect on glioma cell proliferation. AKR1B1 overexpression also inhibited Bcl-2 expression but increased BAX expression, whereas treatment with SB203580 reversed this phenomenon. Furthermore, AKR1B1 induced caspase-3/7 activity. The induction of early and late apoptosis by AKR1B1 was confirmed using an Annexin V-FITC/PI double-staining assay. In conclusion, AKR1B1 regulated glioma cell proliferation through the involvement of p38 MAPK-induced BAX/Bcl-2/caspase-3 apoptosis signaling. Therefore, AKR1B1 may serve as a new therapeutic target for glioma therapy development.

ZNF521/EBF1 axis regulates AKR1B1 to promote the proliferation, migration, and invasion of gastric cancer cells

Although the incidence and death rates of gastric cancer (GC) are decreasing, approximately one million new cases and 800,000 GC-related deaths were reported worldwide in 2018. Currently, the oncogenesis of GC remains unclear, and the demand for novel treatment options are unmet. Here, we explored the role of aldo-keto reductase family 1 member B (AKR1B1) in the progression of GC. The proliferation, migration, and invasion of GC cells were evaluated by CCK-8 assay, wound healing assay, and transwell assay, respectively. The interaction between EBF transcription factor 1 (EBF1) and the promoter region of AKR1B1 was determined by luciferase reporter assay and chromatin immunoprecipitation (ChIP). Gene expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting assay. The expression of AKR1B1 was elevated in GC cells, resulting in increased cell proliferation, migration, and invasion. Meanwhile, EBF1 was a negative regulator of AKR1B1; its overexpression suppressed AKR1B1 expression and GC progression. Furthermore, knockdown of ZNF521 induced EBF1 expression, thus suppressing AKR1B1 expression and resulting in attenuated GC growth and invasiveness. Notably, knockdown of ZNF521 attenuated GC progression and was rescued by overexpression of AKR1B1. Our current study revealed a novel ZNF521/EBF1/AKR1B1 axis in GC and elaborated its important role in promoting GC progression, providing potential therapeutic targets for anti-GC treatments.

METTL3 promotes glycolysis and cholangiocarcinoma progression by mediating the m6A modification of AKR1B10

OBJECTIVE

N6-methyladenosine (m6A) RNA methylation is involved in governing the mechanism of tumor progression. We aimed to excavate the biological role and mechanism of the m6A methyltransferase METTL3 in cholangiocarcinoma (CCA).

METHODS

METTL3 expression was determined by database and tissue microarray analyses. The role of METTL3 in CCA was explored by loss- and gain-of-function experiments. The m6A target of METTL3 was detected by RNA sequencing. The role of AKR1B10 in CCA was explored, and the association between METTL3 and AKR1B10 was confirmed by rescue experiments.

RESULT

METTL3 expression was upregulated in CCA tissue, and higher METTL3 expression was implicated in poor prognoses in CCA patients. Overexpression of METTL3 facilitated proliferation, migration, invasion, glucose uptake, and lactate production in CCA cells, whereas knockdown of METTL3 had the opposite effects. We further found that METTL3 deficiency inhibited CCA tumor growth in vivo. RNA sequencing and MeRIP-qPCR confirmed that METTL3 enhanced AKR1B10 expression and m6A modification levels. Furthermore, METTL3 directly binds with AKR1B10 at an m6A modification site. A CCA tissue microarray showed that AKR1B10 expression was upregulated in CCA tissue and that silencing AKR1B10 suppressed the malignant phenotype mentioned above in CCA. Notably, knockdown of AKR1B10 rescued the tumor-promoting effects induced by METTL3 overexpression.

CONCLUSION

Elevated METTL3 expression promotes tumor growth and glycolysis in CCA through m6A modification of AKR1B10, indicating that METTL3 is a potential target for blocking glycolysis for application in CCA therapy.

Structure-function characterization of an aldo-keto reductase involved in detoxification of the mycotoxin, deoxynivalenol

Deoxynivalenol (DON) is a mycotoxin, produced by filamentous fungi such as Fusarium graminearum, that causes significant yield losses of cereal grain crops worldwide. One of the most promising methods to detoxify this mycotoxin involves its enzymatic epimerization to 3-epi-DON. DepB plays a critical role in this process by reducing 3-keto-DON, an intermediate in the epimerization process, to 3-epi-DON. DepB_Rleg from Rhizobium leguminosarum is a member of the new aldo-keto reductase family, AKR18, and it has the unusual ability to utilize both NADH and NADPH as coenzymes, albeit with a 40-fold higher catalytic efficiency with NADPH compared to NADH. Structural analysis of DepB_Rleg revealed the putative roles of Lys-217, Arg-290, and Gln-294 in NADPH specificity. Replacement of these residues by site-specific mutagenesis to negatively charged amino acids compromised NADPH binding with minimal effects on NADH binding. The substrate-binding site of DepB_Rleg is larger than its closest structural homolog, AKR6A2, likely contributing to its ability to utilize a wide range of aldehydes and ketones, including the mycotoxin, patulin, as substrates. The structure of DepB_Rleg also suggests that 3-keto-DON can adopt two binding modes to facilitate 4-pro-R hydride transfer to either the re- or si-face of the C3 ketone providing a possible explanation for the enzyme's ability to convert 3-keto-DON to 3-epi-DON and DON in diastereomeric ratios of 67.2% and 32.8% respectively.

Identification and chemical profiling of anti-alcoholic liver disease biomarkers of ginseng Huang jiu using UPLC-Q-Orbitrap-HRMS and network pharmacology-based analyses

This study investigated the mechanism of characteristic non-volatile organic compounds (NVOCs) from ginseng Huang jiu (GH) in the treatment of alcoholic liver disease through UPLC-Q-Orbitrap-HRMS and network pharmacological analyses. Changes in NVOC contents in ginseng Huang jiu and ginseng-soaked wine fermented by different processing technologies were analyzed through liquid chromatography–mass spectrometry (LC-MS). A total of 96 ginsenosides were identified in ginseng Huang jiu throughout the fermentation process, which included 37 protopanaxadiol-type ginsenosides, 47 protopanaxatriol-type ginsenosides, and 4 oleanolic acid-type ginsenosides. Orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed that 20(R)-Rg2, Gypenoside XVII, 20(S)-Rf3, CK, Rg5, Rh2, and other rare ginsenosides in ginseng Huang jiu could be the potential index for determining ginseng Huang jiu. In addition, ginseng Huang jiu could improve alcoholic liver disease by regulating the GSTP1, HRAS, AKR1B1, GSTA1, Androgen receptor (AR), GSR, and LDHB genes through bioinformatics analysis. This study provides new insights into improving the industrial production of ginseng Huang jiu and treating alcoholic liver disease with medicinal and food products.

Plasma Aldo-Keto Reductase Family 1 Member B10 as a Biomarker Performs Well in the Diagnosis of Nonalcoholic Steatohepatitis and Fibrosis

We found several blood biomarkers through computational secretome analyses, including aldo-keto reductase family 1 member B10 (AKR1B10), which reflected the progression of nonalcoholic fatty liver disease (NAFLD). After confirming that hepatic AKR1B10 reflected the progression of NAFLD in a subgroup with NAFLD, we evaluated the diagnostic accuracy of plasma AKR1B10 and other biomarkers for the diagnosis of nonalcoholic steatohepatitis (NASH) and fibrosis in replication cohort. We enrolled healthy control subjects and patients with biopsy-proven NAFLD (n = 102) and evaluated the performance of various diagnostic markers. Plasma AKR1B10 performed well in the diagnosis of NASH with an area under the receiver operating characteristic (AUROC) curve of 0.834 and a cutoff value of 1078.2 pg/mL, as well as advanced fibrosis (AUROC curve value of 0.914 and cutoff level 1078.2 pg/mL), with further improvement in combination with C3. When we monitored a subgroup of obese patients who underwent bariatric surgery (n = 35), plasma AKR1B10 decreased dramatically, and 40.0% of patients with NASH at baseline showed a decrease in plasma AKR1B10 levels to below the cutoff level after the surgery. In an independent validation study, we proved that plasma AKR1B10 was a specific biomarker of NAFLD progression across varying degrees of renal dysfunction. Despite perfect correlation between plasma and serum levels of AKR1B10 in paired sample analysis, its serum level was 1.4-fold higher than that in plasma. Plasma AKR1B10 alone and in combination with C3 could be a useful noninvasive biomarker for the diagnosis of NASH and hepatic fibrosis.

Systematic analysis of potential targets of the curcumin analog pentagamavunon-1 (PGV-1) in overcoming resistance of glioblastoma cells to bevacizumab

Background

Glioblastoma is one of the most aggressive and deadliest malignant tumors. Acquired resistance decreases the effectiveness of bevacizumab in glioblastoma treatment and thus increases the mortality rate in patients with glioblastoma. In this study, the potential targets of pentagamavunone-1 (PGV-1), a curcumin analog, were explored as a complementary treatment to bevacizumab in glioblastoma therapy.

Methods

Target prediction, data collection, and analysis were conducted using the similarity ensemble approach (SEA), SwissTargetPrediction, STRING DB, and Gene Expression Omnibus (GEO) datasets. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted using Webgestalt and DAVID, respectively. Hub genes were selected based on the highest degree scores using the CytoHubba. Analysis of genetic alterations and gene expression as well as Kaplan–Meier survival analysis of selected genes were conducted with cBioportal and GEPIA. Immune infiltration correlations between selected genes and immune cells were analyzed with database TIMER 2.0.

Results

We found 374 targets of PGV-1, 1139 differentially expressed genes (DEGs) from bevacizumab-resistant-glioblastoma cells. A Venn diagram analysis using these two sets of data resulted in 21 genes that were identified as potential targets of PGV-1 against bevacizumab resistance (PBR). PBR regulated the metabolism of xenobiotics by cytochrome P450. Seven potential therapeutic PBR, namely GSTM1, AKR1C3, AKR1C4, PTGS2, ADAM10, AKR1B1, and HSD17B110 were found to have genetic alterations in 1.2%–30% of patients with glioblastoma. Analysis using the GEPIA database showed that the mRNA expression of ADAM10, AKR1B1, and HSD17B10 was significantly upregulated in glioblastoma patients. Kaplan–Meier survival analysis showed that only patients with low mRNA expression of AKR1B1 had significantly better overall survival than the patients in the high mRNA group. We also found a correlation between PBR and immune cells and thus revealed the potential of PGV-1 as an immunotherapeutic agent via targeting of PBR.

Conclusion

This study highlighted seven PBR, namely, GSTM1, AKR1C3, AKR1C4, PTGS2, ADAM10, AKR1B1, and HSD17B110. This study also emphasized the potential of PBR as a target for immunotherapy with PGV-1. Further validation of the results of this study is required for the development of PGV-1 as an adjunct to immunotherapy for glioblastoma to counteract bevacizumab resistance.

GLRX3, a novel cancer stem cell-related secretory biomarker of pancreatic ductal adenocarcinoma

Background

Cancer stem cells (CSCs) are implicated in carcinogenesis, cancer progression, and recurrence. Several biomarkers have been described for pancreatic ductal adenocarcinoma (PDAC) CSCs; however, their function and mechanism remain unclear.

Method

In this study, secretome analysis was performed in pancreatic CSC-enriched spheres and control adherent cells for biomarker discovery. Glutaredoxin3 (GLRX3), a novel candidate upregulated in spheres, was evaluated for its function and clinical implication.

Results

PDAC CSC populations, cell lines, patient tissues, and blood samples demonstrated GLRX3 overexpression. In contrast, GLRX3 silencing decreased the in vitro proliferation, migration, clonogenicity, and sphere formation of cells. GLRX3 knockdown also reduced tumor formation and growth in vivo. GLRX3 was found to regulate Met/PI3K/AKT signaling and stemness-related molecules. ELISA results indicated GLRX3 overexpression in the serum of patients with PDAC compared to that in healthy controls. The sensitivity and specificity of GLRX3 for PDAC diagnosis were 80.0 and 100%, respectively. When GLRX3 and CA19–9 were combined, sensitivity was significantly increased to 98.3% compared to that with GLRX3 or CA19–9 alone. High GLRX3 expression was also associated with poor disease-free survival in patients receiving curative surgery.

Conclusion

Overall, these results indicate GLRX3 as a novel diagnostic marker and therapeutic target for PDAC targeting CSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08898-y.

Single-Cell Transcriptomics Reveals the Expression of Aging- and Senescence-Associated Genes in Distinct Cancer Cell Populations

The human aging process is associated with molecular changes and cellular degeneration, resulting in a significant increase in cancer incidence with age. Despite their potential correlation, the relationship between cancer- and ageing-related transcriptional changes is largely unknown. In this study, we aimed to analyze aging-associated transcriptional patterns in publicly available bulk mRNA-seq and single-cell RNA-seq (scRNA-seq) datasets for chronic myelogenous leukemia (CML), colorectal cancer (CRC), hepatocellular carcinoma (HCC), lung cancer (LC), and pancreatic ductal adenocarcinoma (PDAC). Indeed, we detected that various aging/senescence-induced genes (ASIGs) were upregulated in malignant diseases compared to healthy control samples. To elucidate the importance of ASIGs during cell development, pseudotime analyses were performed, which revealed a late enrichment of distinct cancer-specific ASIG signatures. Notably, we were able to demonstrate that all cancer entities analyzed in this study comprised cell populations expressing ASIGs. While only minor correlations were detected between ASIGs and transcriptome-wide changes in PDAC, a high proportion of ASIGs was induced in CML, CRC, HCC, and LC samples. These unique cellular subpopulations could serve as a basis for future studies on the role of aging and senescence in human malignancies.

Genome-wide association study identifies susceptibility loci for acute myeloid leukemia

Acute myeloid leukemia (AML) is a hematological malignancy with an undefined heritable risk. Here we perform a meta-analysis of three genome-wide association studies, with replication in a fourth study, incorporating a total of 4018 AML cases and 10488 controls. We identify a genome-wide significant risk locus for AML at 11q13.2 (rs4930561; P = 2.15 × 10-8; KMT5B). We also identify a genome-wide significant risk locus for the cytogenetically normal AML sub-group (N = 1287) at 6p21.32 (rs3916765; P = 1.51 × 10-10; HLA). Our results inform on AML etiology and identify putative functional genes operating in histone methylation (KMT5B) and immune function (HLA).

Inhibition of AKR1B10-mediated metabolism of daunorubicin as a novel off-target effect for the Bcr-Abl tyrosine kinase inhibitor dasatinib

Bcr-Abl tyrosine kinase inhibitors significantly improved Philadelphia chromosome-positive leukaemia therapy. Apart from Bcr-Abl kinase, imatinib, dasatinib, nilotinib, bosutinib and ponatinib are known to have additional off-target effects that might contribute to their antitumoural activities. In our study, we identified aldo-keto reductase 1B10 (AKR1B10) as a novel target for dasatinib. The enzyme AKR1B10 is upregulated in several cancers and influences the metabolism of chemotherapy drugs, including anthracyclines. AKR1B10 reduces anthracyclines to alcohol metabolites that show less antineoplastic properties and tend to accumulate in cardiac tissue. In our experiments, clinically achievable concentrations of dasatinib selectively inhibited AKR1B10 both in experiments with recombinant enzyme (Ki = 0.6 µM) and in a cellular model (IC₅₀ = 0.5 µM). Subsequently, the ability of dasatinib to attenuate AKR1B10-mediated daunorubicin (Daun) resistance was determined in AKR1B10-overexpressing cells. We have demonstrated that dasatinib can synergize with Daun in human cancer cells and enhance its therapeutic effectiveness. Taken together, our results provide new information on how dasatinib may act beyond targeting Bcr-Abl kinase, which may help to design new chemotherapy regimens, including those with anthracyclines.

Bioinformatic analysis of differentially expressed genes as prognostic markers in pheochromocytoma and paraganglioma tumors

The pathogenesis of pheochromocytoma and paraganglioma (PCPG) catecholamine-producing tumors is exceedingly complicated. Here, we sought to identify important genes affecting the prognosis and survival rate of patients suffering from PCPG. We analyzed 95 samples obtained from two microarray data series, GSE19422 and GSE60459, from the Gene Expression Omnibus (GEO) repository. First, differentially expressed genes (DEGs) were identified by comparing 87 PCPG tumor samples and eight normal adrenal tissue samples using R language. The GEO2R tool and Venn diagram software were applied to the Database for Annotation, Visualization and Integrated Discovery (DAVID) to analyze Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO). We further employed Cytoscape with the Molecular Complex Detection (MCODE) tool to make protein-protein interactions visible for the Search Tool for Retrieval of Interacting Genes (STRING). These procedures resulted in 30 candidate DEGs, which were subjected to Kaplan-Meier analysis and validated by Gene Expression Profiling Interactive Analysis (GEPIA) to determine their influence on overall survival rate. Finally, we identified ALDH3A2 and AKR1B1, two genes in the glycerolipid metabolism pathway, as being particularly enriched in PCPG tumors and correlated with T and B tumor-infiltrating immune cells. Our results suggest that these two DEGs are closely associated with the prognosis of malignant PCPG tumors.

Aldo-keto reductase inhibitors increase the anticancer effects of tyrosine kinase inhibitors in chronic myelogenous leukemia

Tyrosine kinase inhibitors (TKIs) are widely utilized in clinical practice to treat carcinomas, but secondary tumor resistance during chronic treatment can be problematic. AKR1B1 and AKR1B10 of the aldo-keto reductase (AKR) superfamily are highly expressed in cancer cells and are believed to be involved in drug resistance. The aim of this study was to understand how TKI treatment of chronic myelogenous leukemia (CML) cells changes their glucose metabolism and if inhibition of AKRs can sensitize CML cells to TKIs. K562 cells were treated with the TKIs imatinib, nilotinib, or bosutinib, and the effects on glucose metabolism, cell death, glutathione levels, and AKR levels were assessed. To assess glucose dependence, cells were cultured in normal and low-glucose media. Pretreatment with AKR inhibitors, including epalrestat, were used to determine AKR-dependence. Treatment with TKIs increased intracellular glucose, AKR1B1/10 levels, glutathione oxidation, and nuclear translocation of nuclear factor erythroid 2-related factor 2, but with minimal cell death. These effects were dependent on intracellular glucose accumulation. Pretreatment with epalrestat, or a selective inhibitor of AKR1B10, exacerbated TKI-induced cell death, suggesting that especially AKR1B10 was involved in protection against TKIs. Thus, by disrupting cell protective mechanisms, AKR inhibitors may render CML more susceptible to TKI treatments.

(-)-Kusunokinin as a Potential Aldose Reductase Inhibitor: Equivalency Observed via AKR1B1 Dynamics Simulation

(-)-Kusunokinin performed its anticancer potency through CFS1R and AKT pathways. Its ambiguous binding target has, however, hindered the next development phase. Our study thus applied molecular docking and molecular dynamics simulation to predict the protein target from the pathways. Among various candidates, aldo-keto reductase family 1 member B1 (AKR1B1) was finally identified as a (-)-kusunokinin receptor. The predicted binding affinity of (-)-kusunokinin was better than the selected aldose reductase inhibitors (ARIs) and substrates. The compound also had no significant effect on AKR1B1 conformation. An intriguing AKR1B1 efficacy, with respect to the known inhibitors (epalrestat, zenarestat, and minalrestat) and substrates (UVI2008 and prostaglandin H₂), as well as a similar interactive insight of the enzyme pocket, pinpointed an ARI equivalence of (-)-kusunokinin. An aromatic ring and a γ-butyrolactone ring shared a role with structural counterparts in known inhibitors. The modeling explained that the aromatic constituent contributed to π-π attraction with Trp111. In addition, the γ-butyrolactone ring bound the catalytic His110 using hydrogen bonds, which could lead to enzymatic inhibition as a consequence of substrate competitiveness. Our computer-based findings suggested that the potential of (-)-kusunokinin could be furthered by in vitro and/or in vivo experiments to consolidate (-)-kusunokinin as a new AKR1B1 antagonist in the future.

Bruton's Tyrosine Kinase Inhibitors Ibrutinib and Acalabrutinib Counteract Anthracycline Resistance in Cancer Cells Expressing AKR1C3

Simple Summary

The enzyme aldo-keto reductase 1C3 (AKR1C3) is present in several cancers, in which it is capable of actively metabolising different chemotherapy drugs and decreasing their cytotoxic effects. Therefore, the combination with specific inhibitors of AKR1C3 might prevent drug metabolism and increase its efficacy. We investigated the ability of Bruton’s tyrosine kinase inhibitors ibrutinib and acalabrutinib to block the AKR1C3 mediated inactivation of the anthracycline daunorubicin. Experimentation with recombinant AKR1C3 and different cancer cells expressing this enzyme outlined BTK-inhibitors as potential partners to synergise daunorubicin cytotoxicity in vitro. This evidence could be useful to improve the clinical outcome of anthracycline-based chemotherapies.

Abstract

Over the last few years, aldo-keto reductase family 1 member C3 (AKR1C3) has been associated with the emergence of multidrug resistance (MDR), thereby hindering chemotherapy against cancer. In particular, impaired efficacy of the gold standards of induction therapy in acute myeloid leukaemia (AML) has been correlated with AKR1C3 expression, as this enzyme metabolises several drugs including anthracyclines. Therefore, the development of selective AKR1C3 inhibitors may help to overcome chemoresistance in clinical practice. In this regard, we demonstrated that Bruton’s tyrosine kinase (BTK) inhibitors ibrutinib and acalabrutinib efficiently prevented daunorubicin (Dau) inactivation mediated by AKR1C3 in both its recombinant form as well as during its overexpression in cancer cells. This revealed a synergistic effect of BTK inhibitors on Dau cytotoxicity in cancer cells expressing AKR1C3 both exogenously and endogenously, thus reverting anthracycline resistance in vitro. These findings suggest that BTK inhibitors have a novel off-target action, which can be exploited against leukaemia through combination regimens with standard chemotherapeutics like anthracyclines.

Targeting NPL4 via drug repositioning using disulfiram for the treatment of clear cell renal cell carcinoma

The alcohol-abuse drug disulfiram has antitumor effects against diverse cancer types via inhibition of the ubiquitin-proteasome protein nuclear protein localization protein 4 (NPL4). However, the antitumor effects of NPL4 and disulfiram in clear cell renal cell carcinoma (ccRCC) are unclear. Here, we evaluated the therapeutic potential of targeting the ubiquitin-proteasome pathway using disulfiram and RNA interference and investigated the mechanisms underlying disulfiram in ccRCC. According to data from The Cancer Genome Atlas, NPL4 mRNA expression was significantly upregulated in clinical ccRCC samples compared with that in normal kidney samples, and patients with high NPL4 expression had poor overall survival compared with patients with low NPL4 expression. Disulfiram and NPL4 siRNA inhibited ccRCC cell proliferation in vitro, and disulfiram inhibited ccRCC tumor growth in a xenograft model. Synergistic antiproliferative effects were observed for combination treatment with disulfiram and sunitinib in vitro and in vivo. In RCC cells from mice treated with disulfiram and/or sunitinib, several genes associated with serine biosynthesis and aldose reductase were downregulated in cells treated with disulfiram or sunitinib alone and further downregulated in cells treated with both disulfiram and sunitinib. These findings provided insights into the mechanisms of disulfiram and suggested novel therapeutic strategies for RCC treatment.

Role of aldo-keto reductase family 1 member B1 (AKR1B1) in the cancer process and its therapeutic potential

The role of aldo‐keto reductase family 1 member B1 (AKR1B1) in cancer is not totally clear but growing evidence is suggesting to have a great impact on cancer progression. AKR1B1 could participate in a complicated network of signalling pathways, proteins and miRNAs such as mir‐21 mediating mechanisms like inflammatory responses, cell cycle, epithelial to mesenchymal transition, cell survival and apoptosis. AKR1B1 has been shown to be mostly overexpressed in cancer. This overexpression has been associated with inflammatory mediators including nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NFκB), cell cycle mediators such as cyclins and cyclin‐dependent kinases (CDKs), survival proteins and pathways like mammalian target of rapamycin (mTOR) and protein kinase B (PKB) or AKT, and other regulatory factors in response to reactive oxygen species (ROS) and prostaglandin synthesis. In addition, inhibition of AKR1B1 has been shown to mostly have anti‐cancer effects. Several studies have also suggested that AKR1B1 inhibition as an adjuvant therapy could render tumour cells more sensitive to anti‐cancer therapy or alleviate the adverse effects of therapy. AKR1B1 could also be considered as a potential cancer diagnostic biomarker since its promoter has shown high levels of methylation. Although pre‐clinical investigations on the role of AKR1B1 in cancer and the application of its inhibitors have shown promising results, the lack of clinical studies on AKR1B1 inhibitors has hampered the use of these drugs to treat cancer. Thus, there is a need to conduct more clinical studies on the application of AKR1B1 inhibitors as adjuvant therapy on different cancers.

Loss of AKR1B10 promotes colorectal cancer cells proliferation and migration via regulating FGF1-dependent pathway

Colorectal cancer (CRC) is a common malignancy worldwide with poor prognosis and survival rates. The aldo-keto reductase family 1 member B10 (AKR1B10) plays an important role in metabolism, cell proliferation and mobility, and is downregulated in CRC. We hypothesized that AKR1B10 would promote CRC genesis via a noncanonical oncogenic pathway and is a novel therapeutic target. In this study, AKR1B10 expression levels in 135 pairs of CRC and para-tumor tissues were examined, and its oncogenic role was determined using in vitro and in vivo functional assays following genetic manipulation of CRC cells. AKR1B10 was downregulated in CRC tissues compared to the adjacent normal colorectal tissues, and associated with the clinicopathological status of the patients. AKR1B10 depletion promoted the proliferation and migration of CRC cells in vitro, while its ectopic expression had the opposite effect. AKR1B10 was also significantly correlated with FGF1 gene and protein levels. Knockdown of AKR1B10 promoted tumor growth in vivo, and increased the expression of FGF1. Finally, AKR1B10 inhibited FGF1, and suppressed the proliferation and migration ability of CRC cells in an FGF1-dependent manner. In conclusion, AKR1B10 acts as a tumor suppressor in CRC by inactivating FGF1, and is a novel target for combination therapy of CRC.

Targeting Pharmacokinetic Drug Resistance in Acute Myeloid Leukemia Cells with CDK4/6 Inhibitors

Pharmacotherapy of acute myeloid leukemia (AML) remains challenging, and the disease has one of the lowest curability rates among hematological malignancies. The therapy outcomes are often compromised by the existence of a resistant AML phenotype associated with overexpression of ABCB1 and ABCG2 transporters. Because AML induction therapy frequently consists of anthracycline-like drugs, their efficiency may also be diminished by drug biotransformation via carbonyl reducing enzymes (CRE). In this study, we investigated the modulatory potential of the CDK4/6 inhibitors abemaciclib, palbociclib, and ribociclib on AML resistance using peripheral blood mononuclear cells (PBMC) isolated from patients with de novo diagnosed AML. We first confirmed inhibitory effect of the tested drugs on ABCB1 and ABCG2 in ABC transporter-expressing resistant HL-60 cells while also showing the ability to sensitize the cells to cytotoxic drugs even as no effect on AML-relevant CRE isoforms was observed. All tested CDK4/6 inhibitors elevated mitoxantrone accumulations in CD34⁺ PBMC and enhanced accumulation of mitoxantrone was found with abemaciclib and ribociclib in PBMC of FLT3-ITD^- patients. Importantly, the accumulation rate in the presence of CDK4/6 inhibitors positively correlated with ABCB1 expression in CD34⁺ patients and led to enhanced apoptosis of PBMC in contrast to CD34⁻ samples. In summary, combination therapy involving CDK4/6 inhibitors could favorably target multidrug resistance, especially when personalized based on CD34⁻ and ABCB1-related markers.

The Expression and Clinical Significance of Aldo-Keto Reductase 1 Member B1 in Gastric Carcinoma

To study the expression of aldo-keto reductase 1 member B1 (AKR1B1) in gastric carcinoma (GC), the correlation between AKR1B1 and the clinicopathological characteristics of GC patients, and provide reference for the diagnosis and prognosis of GC patients. One hundred thirty-six patients with GC were collected, and the expression level of AKR1B1 in GC and adjacent tissues was detected by immunohistochemistry assays. The clinicopathological features and prognosis of GC patients were collected to analyze the relationship with AKR1B1 expression. The positive expression of AKR1B1 in GC tissues was significantly higher than that of adjacent nontumor tissues. The difference of AKR1B1 expression between GC tissues and paired adjacent nontumor tissues was statistically significant (p < 0.001). AKR1B1 was closely related to tumor size, regional lymph node (N), metastases (M), and tumor-node-metastasis (TNM) stage (p < 0.05). The overall survival of patients with low expression of AKR1B1 was significantly better than that of patients with high expression of AKR1B1 by Kaplan-Meier survival analysis (p < 0.001). AKR1B1 plays an important role in the occurrence and development of GC, and it has a certain reference value for the prognosis of GC patients.

Pathways of 4-Hydroxy-2-Nonenal Detoxification in a Human Astrocytoma Cell Line

One of the consequences of the increased level of oxidative stress that often characterizes the cancer cell environment is the abnormal generation of lipid peroxidation products, above all 4-hydroxynonenal. The contribution of this aldehyde to the pathogenesis of several diseases is well known. In this study, we characterized the ADF astrocytoma cell line both in terms of its pattern of enzymatic activities devoted to 4-hydroxynonenal removal and its resistance to oxidative stress induced by exposure to hydrogen peroxide. A comparison with lens cell lines, which, due to the ocular function, are normally exposed to oxidative conditions is reported. Our results show that, overall, ADF cells counteract oxidative stress conditions better than normal cells, thus confirming the redox adaptation demonstrated for several cancer cells. In addition, the markedly high level of NADP⁺-dependent dehydrogenase activity acting on the glutahionyl-hydroxynonanal adduct detected in ADF cells may promote, at the same time, the detoxification and recovery of cell-reducing power in these cells.

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.

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.

Aldose reductase inhibitors: 2013-present

INTRODUCTION

Aldose reductase (ALR2) is both the key enzyme of the polyol pathway, whose activation under hyperglycemic conditions leads to the development of chronic diabetic complications, and the crucial promoter of inflammatory and cytotoxic conditions, even under a normoglycemic status. Accordingly, it represents an excellent drug target and a huge effort is being done to disclose novel compounds able to inhibit it.

AREAS COVERED

This literature survey summarizes patents and patent applications published over the last 5 years and filed for natural, semi-synthetic and synthetic ALR2 inhibitors. Compounds described have been discussed and analyzed from both chemical and functional angles.

EXPERT OPINION

Several ALR2 inhibitors with a promising pre-clinical ability to address diabetic complications and inflammatory diseases are being developed during the observed timeframe. Natural compounds and plant extracts are the prevalent ones, thus confirming the use of phytopharmaceuticals as an increasingly pursued therapeutic trend also in the ALR2 inhibitors field. Intriguing hints may be taken from synthetic derivatives, the most significant ones being represented by the differential inhibitors ARDIs. Differently from classical ARIs, these compounds should fire up the therapeutic efficacy of the class while minimizing its side effects, thus overcoming the existing limits of this kind of inhibitors.

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.

AKR1B10 expression predicts response of gastric cancer to neoadjuvant chemotherapy

Effective methods for predicting tumor response to preoperative chemotherapy are required. Aldo-ketoreductase family 1 member B10 (AKR1B10) is predominantly expressed in the gastrointestinal tract and serves an important function in cancer development and progression. The present study investigated whether AKR1B10 expression may predict the therapeutic response of locally advanced gastric cancer. A total of 53 patients with gastric cancer underwent neoadjuvant chemotherapy followed by surgery between January 2006 and December 2015. The protein expression level of AKR1B10 was determined in paraffin-embedded biopsy specimens using immunohistochemistry. Western blotting confirmed that the AKR1B10 protein is primarily localized to the cytoplasm. χ² and Fisher's exact tests were used to determine the association of AKR1B10 with a number of clinic opathological features. Univariate and multivariate analyses were used to identify the prognostic factors. Survival rates were compared using Kaplan-Meier curves with a log-rank test. The positive rate of AKR1B10 protein expression was 58.5%, whereas 41.5% samples exhibited negative expression. The frequency of AKR1B10-positive gastric cancer samples was increased in patients with lymph node metastasis and decreased in those exhibiting tumor regression. The 5-years overall survival rate for the AKR1B10-positive group was significantly poorer than that for the AKR1B10-negative group. AKR1B10 expression was associated with lymph node metastasis and a poorer prognosis, along with a poor response to neoadjuvant chemotherapy suggesting that AKR1B10 may be a potential predictor for the therapeutic response of locally-advanced gastric cancer.

hiPSC hepatocyte model demonstrates the role of unfolded protein response and inflammatory networks in α1-antitrypsin deficiency

BACKGROUND & AIMS

α1-Antitrypsin deficiency (A1ATD) is an autosomal recessive disorder caused by mutations in the SERPINA1 gene. Individuals with the Z variant (Gly342Lys) retain polymerised protein in the endoplasmic reticulum (ER) of their hepatocytes, predisposing them to liver disease. The concomitant lack of circulating A1AT also causes lung emphysema. Greater insight into the mechanisms that link protein misfolding to liver injury will facilitate the design of novel therapies.

METHODS

Human-induced pluripotent stem cell (hiPSC)-derived hepatocytes provide a novel approach to interrogate the molecular mechanisms of A1ATD because of their patient-specific genetic architecture and reflection of human physiology. To that end, we utilised patient-specific hiPSC hepatocyte-like cells (ZZ-HLCs) derived from an A1ATD (ZZ) patient, which faithfully recapitulated key aspects of the disease at the molecular and cellular level. Subsequent functional and "omics" comparisons of these cells with their genetically corrected isogenic-line (RR-HLCs) and primary hepatocytes/human tissue enabled identification of new molecular markers and disease signatures.

RESULTS

Our studies showed that abnormal A1AT polymer processing (immobilised ER components, reduced luminal protein mobility and disrupted ER cisternae) occurred heterogeneously within hepatocyte populations and was associated with disrupted mitochondrial structure, presence of the oncogenic protein AKR1B10 and two upregulated molecular clusters centred on members of inflammatory (IL-18 and Caspase-4) and unfolded protein response (Calnexin and Calreticulin) pathways. These results were validated in a second patient-specific hiPSC line.

CONCLUSIONS

Our data identified novel pathways that potentially link the expression of Z A1AT polymers to liver disease. These findings could help pave the way towards identification of new therapeutic targets for the treatment of A1ATD.

LAY SUMMARY

This study compared the gene expression and protein profiles of healthy liver cells and those affected by the inherited disease α1-antitrypsin deficiency. This approach identified specific factors primarily present in diseased samples which could provide new targets for drug development. This study also demonstrates the interest of using hepatic cells generated from human-induced pluripotent stem cells to model liver disease in vitro for uncovering new mechanisms with clinical relevance.

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.

Aldo-keto reductases-mediated cytotoxicity of 2-deoxyglucose: A novel anticancer mechanism

2‐Deoxyglucose (2DG) is a non‐metabolizable glucose analog currently in clinical trials to determine its efficacy in enhancing the therapeutic effects of radiotherapy and chemotherapy of several types of cancers. It is thought to preferentially kill cancer cells by inhibiting glycolysis because cancer cells are more dependent on glycolysis for their energy needs than normal cells. However, we found that the toxicity of 2DG in cancer cells is mediated by the enzymatic activities of AKR1B1 and/or AKR1B10 (AKR1Bs), which are often overexpressed in cancer cells. Our results show that 2DG kills cancer cells because, in the process of being reduced by AKR1Bs, depletion of their cofactor NADPH leads to the depletion of glutathione (GSH) and cell death. Furthermore, we showed that compounds that are better substrates for AKR1Bs than 2DG are more effective than 2DG in killing cancer cells that overexpressed these 2 enzymes. As cancer cells can be induced to overexpress AKR1Bs, the anticancer mechanism we identified can be applied to treat a large variety of cancers. This should greatly facilitate the development of novel anticancer drugs.

4-Hydroxynonenal metabolites and adducts in pre-carcinogenic conditions and cancer

4-hydroxy-2-nonenal (HNE) is an amazing reactive compound, originating from lipid peroxidation within cells but also in food and considered as a "second messenger" of oxidative stress. Due to its chemical features, HNE is able to make covalent links with DNA, proteins and lipids. The aim of this review is to give a comprehensive summary of the chemical properties of HNE and of the consequences of its reactivity in relation to cancer development. The formation of exocyclic etheno-and propano-adducts and genotoxic effects are addressed. The adduction to cellular proteins and the repercussions on the regulation of cell signaling pathways involved in cancer development are reviewed, notably on the Nrf2/Keap1/ARE pathway. The metabolic pathways leading to the inactivation/elimination or, on the contrary, to the bioactivation of HNE are considered. A special focus is given on the link between HNE and colorectal cancer development, due to its occurrence in foodstuffs and in the digestive lumen, during digestion.

Opposing roles of the aldo-keto reductases AKR1B1 and AKR1B10 in colorectal cancer

PURPOSE

Aldo-keto reductases (including AKR1B1 and AKR1B10) constitute a family of oxidoreductases that have been implicated in the pathophysiology of diabetes and cancer, including colorectal cancer (CRC). Available data indicate that, despite their similarities in structure and enzymatic functions, their roles in CRC may be divergent. Here, we aimed to determine the expression and functional implications of AKR1B1 and AKR1B10 in CRC.

METHODS

AKR1B1 and AKR1B10 gene expression levels were analyzed using publicly available microarray data and ex vivo CRC-derived cDNA samples. Gene Set Enrichment Analysis (GSEA), The Cancer Genome Atlas (TCGA) RNA-seq data and The Cancer Proteome Atlas (TCPA) proteome data were analyzed to determine the effect of high and low AKR1B1 and AKR1B10 expression levels in CRC patients. Proliferation, cell cycle progression, cellular motility, adhesion and inflammation were determined in CRC-derived cell lines in which these genes were either exogenously overexpressed or silenced.

RESULTS

We found that the expression of AKR1B1 was unaltered, whereas that of AKR1B10 was decreased in primary CRCs. GSEA revealed that, while high AKR1B1 expression was associated with increased cell cycle progression, cellular motility and inflammation, high AKR1B10 expression was associated with a weak inflammatory phenotype. Functional studies carried out in CRC-derived cell lines confirmed these data. Microarray data analysis indicated that high expression levels of AKR1B1 and AKR1B10 were significantly associated with shorter and longer disease-free survival rates, respectively. A combined gene expression signature of AKR1B10 (low) and AKR1B1 (high) showed a better prognostic stratification of CRC patients independent of confounding factors.

CONCLUSIONS

Despite their similarities, the expression levels and functions of AKR1B1 and AKR1B10 are highly divergent in CRC, and they may have prognostic implications.

Stereospecific Metabolism of R- and S-Warfarin by Human Hepatic Cytosolic Reductases

Coumadin (rac-warfarin) is the most commonly used anticoagulant in the world; however, its clinical use is often challenging because of its narrow therapeutic range and interindividual variations in response. A critical contributor to the uncertainty is variability in warfarin metabolism, which includes mostly oxidative but also reductive pathways. Reduction of each warfarin enantiomer yields two warfarin alcohol isomers, and the corresponding four alcohols retain varying levels of anticoagulant activity. Studies on the kinetics of warfarin reduction have often lacked resolution of parent-drug enantiomers and have suffered from coelution of pairs of alcohol metabolites; thus, those studies have not established the importance of individual stereospecific reductive pathways. We report the first steady-state analysis of R- and S-warfarin reduction in vitro by pooled human liver cytosol. As determined by authentic standards, the major metabolites were 9R,11S-warfarin alcohol for R-warfarin and 9S,11S-warfarin alcohol for S-warfarin. R-warfarin (Vmax 150 pmol/mg per minute, Km 0.67 mM) was reduced more efficiently than S-warfarin (Vmax 27 pmol/mg per minute, Km 1.7 mM). Based on inhibitor phenotyping, carbonyl reductase-1 dominated R-and S-warfarin reduction, followed by aldo-keto reductase-1C3 and then other members of that family. Overall, the carbonyl at position 11 undergoes stereospecific reduction by multiple enzymes to form the S alcohol for both drug enantiomers, yet R-warfarin undergoes reduction preferentially. This knowledge will aid in assessing the relative importance of reductive pathways for R- and S-warfarin and factors influencing levels of pharmacologically active parent drugs and metabolites, thus impacting patient dose responses.

STAR and AKR1B10 are down-regulated in high-grade endometrial cancer

Endometrial cancer is the most frequent gynecological malignancy in the developed world. The majority of cases are estrogen dependent, and are associated with diminished protective effects of progesterone. Endometrial cancer is also related to enhanced inflammation and decreased differentiation. In our previous studies, we examined the expression of genes involved in estrogen and progesterone actions in inflammation and tumor differentiation, in tissue samples from endometrial cancer and adjacent control endometrium. The aims of the current study were to examine correlations between gene expression and several demographic characteristics, and to evaluate changes in gene expression with regard to histopathological and clinical characteristics of 51 patients. We studied correlations and differences in expression of 38 genes involved in five pathophysiological processes: (i) estrogen-stimulated proliferation; (ii) estrogen-dependent carcinogenesis; (iii) diminished biosynthesis of progesterone: (iv) enhanced formation of progesterone metabolites; and (v) increased inflammation and decreased differentiation. Spearman correlation coefficient analysis shows that expression of PAQR7 correlates with age, expression of SRD5A1, AKR1B1 and AKR1B10 correlate with body mass, while expression of SRD5A1 and AKR1B10 correlate with body mass index. When patients with endometrial cancer were stratified based on menopausal status, histological grade, myometrial invasion, lymphovascular invasion, and FIGO stage, Mann-Whitney U tests revealed significantly decreased expression of STAR (4.4-fold; adjusted p=0.009) and AKR1B10 (9-fold; adjusted p=0.003) in high grade versus low grade tumors. Lower levels of STAR might lead to decreased de-novo steroid hormone synthesis and tumor differentiation, and lower levels of AKR1B10 to diminished elimination of toxic electrophilic carbonyl compounds in high-grade endometrial cancer. These data thus reveal the potential of STAR and AKR1B10 as prognostic biomarkers, which calls for further validation at the protein level.

Aldose reductase inhibitor increases doxorubicin-sensitivity of colon cancer cells and decreases cardiotoxicity

Anthracycline drugs such as doxorubicin (DOX) and daunorubicin remain some of the most active wide-spectrum and cost-effective drugs in cancer therapy. However, colorectal cancer (CRC) cells are inherently resistant to anthracyclines which at higher doses cause cardiotoxicity. Our recent studies indicate that aldose reductase (AR) inhibitors such as fidarestat inhibit CRC growth in vitro and in vivo. Here, we show that treatment of CRC cells with fidarestat increases the efficacy of DOX-induced death in HT-29 and SW480 cells and in nude mice xenografts. AR inhibition also results in higher intracellular accumulation of DOX and decreases the expression of drug transporter proteins MDR1, MRP1, and ABCG2. Further, fidarestat also inhibits DOX-induced increase in troponin-I and various inflammatory markers in the serum and heart and restores cardiac function in mice. These results suggest that fidarestat could be used as adjuvant therapy to enhance DOX sensitivity of CRC cells and to reduce DOX-associated cardiotoxicity.

Aldo-keto reductase activity after diethylhexyl phthalate exposure in eutopic and ectopic endometrial cells

OBJECTIVE

Endometriosis is a multifactorial gynaecological disease in reproductive-age women. Endometriotic tissue is characterized by high prostaglandin levels and progesterone resistance. Human aldo-keto reductases (AKRs) convert progesterone to a less potent metabolite and cause progesterone resistance. Therefore, in this study, we evaluated whether diethylhexyl phthalate (DEHP) alters AKR expression in human ectopic and eutopic endometrium.

STUDY DESIGN

We used microarrays and western blotting to study the effects of DEHP, and checked the presence of AKR in endometriosis patients by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Cultured human endometrial cells from normal endometrium of women without endometriosis (NE), eutopic endometrium from endometriosis patients (EE), and ectopic endometrium from endometriosis patients (EC) differed in genetic expression changes after DEHP treatment. DEHP upregulated AKR1C1, AKR1C2, AKR1C3, and AKR1B10 expression in EE, while EC showed continuously increased AKR1C3 expression before and after DEHP exposure. In western blot analysis, before and after DEHP exposure, the AKR1B10 protein band was detected in NE, EE, and EC, whereas the AKR1C3 band was detected only in EC. AKR1B10 and AKR1C3 expression levels in the blood of the enrolled patients were evaluated using ELISA. AKR1B10 expression did not differ between groups (without endometriosis [N=13], 0.10 vs. with endometriosis [N=20], 0.11; P=0.27). AKR1C3 expression was significantly higher in the blood of endometriosis patients than in that of patients without endometriosis (without endometriosis, 9.1 vs. with endometriosis, 10.1; P=0.02). Analysis according to menstrual period showed significantly increased AKR1C3 levels in patients with endometriosis only during the secretory phase and not the proliferative phase (P<0.05).

CONCLUSION

DEHP induces AKR activity in the endometrium of endometriosis patients, and AKR1C3 might influence the development of endometriosis.

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.

AKR1B10-inhibitory Selaginella tamariscina extract and amentoflavone decrease the growth of A549 human lung cancer cells in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Selaginella tamariscina (P.Beauv.) Spring is a traditional medicinal plant used to treat various human diseases, including cancer, in Asia. The detailed molecular mechanism underlying the anti-cancer effects of this plant and the anti-cancer action of the combinatorial treatment of S. tamariscina and doxorubicin have not yet been investigated.

AIM OF THE STUDY

We evaluated the inhibitory activity of S. tamariscina extract (STE) and its major compound, amentoflavone, on human aldo-keto reductase family 1B10 (AKR1B10), which is a detoxification enzyme involved in drug resistance, to evaluate their anti-cancer effects and their potential as adjuvant agents for doxorubicin cancer chemotherapy.

MATERIALS AND METHODS

We tested the AKR1B10 inhibitory activity of STE and amentoflavone via an in vitro biochemical assay using recombinant human AKR1B10. We tested the anti-proliferative activity in A549, NCI-H460, SKOV-3, and MCF-7 human cancer cells, which contain different expression levels of AKR1B10, and determined the combination index to evaluate whether the addition of STE and amentoflavone is synergistic or antagonistic to the anti-cancer action of doxorubicin. We finally evaluated the in vivo anti-tumor effects of STE in a nude mouse xenograft model of A549 cells.

RESULTS

STE and amentoflavone potently inhibited human AKR1B10 and synergistically increased the doxorubicin anti-proliferative effect in A549 and NCI-H460 human lung cancer cells that express a high level of AKR1B10 mRNA and protein. STE also significantly inhibited A549 tumor growth in animal experiments.

CONCLUSION

Our results suggest that STE and amentoflavone could be potential anti-cancer agents that target AKR1B10 and might be candidate adjuvant agents to boost the anti-cancer effect of doxorubicin.

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.