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.

Aldo-keto reductase family member C3(AKR1C3)promotes hepatocellular carcinoma cell growth by producing prostaglandin F2α

Hepatocellular carcinoma(HCC)is a leading cause of death worldwide.Current therapies are effective for HCC patients with early disease,but many patients suffer recurrence after surgery and have a poor response to chemotherapy.Therefore,new therapeutic targets are needed.We analyzed gene expression profiles between HCC tissues and normal adjacent tissues from public databases and found that the expression of genes involved in lipid metabolism was significantly different.The analysis showed that AKR1C3 was upregulated in tumors,and high AKR1C3 expression was associated with a poorer prognosis in HCC patients.In vitro,assays demonstrated that the knockdown of AKR1C3 or the addition of the AKR1C3 inhibitor indomethacin suppressed the growth and colony formation of HCC cell lines.Knockdown of AKR1C3 in Huh7 cells reduced tumor growth in vivo.To explore the mechanism,we performed pathway enrichment analysis,and the results linked the expression of AKR1C3 with prostaglandin F2 alpha(PGF2a)downstream target genes.Suppression of AKR1C3 activity reduced the production of PGF2a,and supplementation with PGF2a restored the growth of indomethacin-treated Huh7 cells.Knockdown of the PGF receptor(PTGFR)and treatment with a PTGFR inhibitor significantly reduced HCC growth.We showed that indomethacin potentiated the sensitivity of Huh7 cells to sorafenib.In summary,our results indicate that AKR1C3 upregulation may promote HCC growth by promoting the production of PGF2α,and suppression of PTGFR limited HCC growth.Therefore,targeting the AKR1C3-PGF2a-PTGFR axis may be a new strategy for the treatment of HCC.

Analysis of the mechanism of aldo-keto reductase dependent cis-platin resistance in HepG2 cells based on transcriptomic and NADH metabolic state

Background:Aldo-keto oxidoreductase(AKR)inhibitors could reverse the resistance of several cancer cells to cis-platin,but their role in resistance remains unclear.Methods:We verified the difference of AKR1Cs expression by Western blot,RNA sequencing and qRT-PCR.The differences of AKR1Cs expression were analyzed and inferred.Use Assay of NADH and NAD^(+)content to verify the inference.The Docking experience was used to verify the affinity between MPA,MCFLA,MLS and AKR1C3.Results:Our RNA-seq results showed de novo NAD biosynthesis-related genes and NAD(P)H-dependent oxidoreductases were significantly upregulated in cis-platin-resistant HepG2 hepatic cancer cells(HepG2-RC cells)compared with HepG2 cells.At least 63 NAD(P)H-dependent reductase/oxidases were upregulated in HepG2-RC cells at least twofold.Knockdown of AKR1Cs could increase cis-platin sensitivity in HepG2-RC cells about two-fold.Interestingly,the AKR1C inhibitor meclofenamic acid could increase the cis-platin sensitivity of HepG2-RC cells about eight-fold,indicating that the knockdown of AKR1Cs only partially reversed the resistance.Meanwhile,the amount of total NAD and the ratio of NADH/NAD^(+)were increased in HepG2-RC cells compared with HepG2 cells.The ratio of NADH/NAD^(+)in HepG2-RC cells was almost seven-fold higher than in HepG2 or HL-7702 cells.Increased NADH expression could be explained as a directly operating antioxidant to scavenge cis-platin-induced radicals.Conclusion:We report here that NADH,which is produced by NAD(P)Hdependent oxidoreductases,plays a key role in the AKR-associated cis-platin resistance of HepG2 hepatic cancer cells.

Expression Analysis of Aldo-Keto Reductase 1 (AKR1) in Foxtail Millet (Setaria italica L.) Subjected to Abiotic Stresses

Foxtail millet (Setaria italica L.) is a drought-tolerant millet crop of arid and semi-arid regions. Aldo-keto reductases (AKRs) are significant part of plant defence mechanism, having an ability to confer multiple stress tolerance. In this study, AKR1 gene expression was studied in roots and leaves of foxtail millet subjected to different regimes of PEG- and NaCl-stress for seven days. The quantitative Real-time PCR expression analysis in both root and leaves showed upregulation of AKR1 gene during PEG and salt stress. A close correlation exits between expression of AKR1 gene and the rate of lipid peroxidation along with the retardation of growth. Tissue-specific differences were found in the AKR1 gene expression to the stress intensities studied. The reduction in root and shoot growth under both stress conditions were dependent on stress severity. The level of lipid peroxidation as indicated by MDA formation was significantly increased in roots and leaves along with increased stress levels. Finally, these findings support the early responsive nature of AKR1 gene and seem to be associated at least in part with its ability to contribute in antioxidant defence related pathways which could provide a better protection against oxidative stress under stress conditions.

Synthesis and Characterization of Naproxen-Salicylate Derivatives as Potential Dual-Targeted Inhibitors of Dihydrofolate Reductase

Dihydrofolate reductase (DHFR) is an enzyme that catalyzes the reduction of dihydrofolate (DHF) to tetrahydrofolate (THF). Chemotherapy drugs such as methotrexate help to slow the progression of cancer by limiting the ability of dividing cells to make nucleotides by competitively inhibiting DHFR. Nonsteroidal anti-inflammatory drugs (NSAIDs) have been previously reported to exhibit competitive inhibition of DHFR, in addition to their primary action on cyclooxygenase enzymes. This interaction interferes with the enzymatic reduction of dihydrofolate to tetrahydrofolate, thereby impeding the folate metabolism pathway essential for nucleotide synthesis and cell proliferation. This activity stems from their structural resemblance to the p-aminobenzoyl-l-glutamate (pABG) moiety of folate, a substrate of DHFR. It has been established that NSAIDs containing a salicylate group (which has structural similarities to pABG), such as diflunisal, exhibit stronger DHFR-binding activity. In this study, we synthesized salicylate derivatives of naproxen with the aim of exploring their potential as inhibitors of DHFR. The interactions between these derivatives and human DHFR were characterized using a combination of biochemical, biophysical, and structural methods. Through polyacrylamide gel electrophoresis (PAGE) analysis, enzymatic assays, and quantitative ELISA, we investigated the binding affinity and inhibitory potency of the synthesized salicylate derivatives towards DHFR. The findings of this study suggest the potential of salicylate derivatives of naproxen as promising candidates for the inhibition of DHFR, thereby offering novel therapeutic opportunities for modulating the inflammatory process through multiple pathways. Further optimization of these derivatives could lead to the development of more efficacious dual-targeted analogs with enhanced therapeutic benefits.

Berberine inhibits androgen synthesis by interaction with aldo-keto reductase 1C3 in 22Rv1 prostate cancer cells

AIdo-keto reductase family 1 member C3 has recently been regarded as a potential therapeutic target in castrate-resistant prostate cancer. Herein, we investigated whether berberine delayed the progression of castrate-resistant prostate cancer by reducing androgen synthesis through the inhibition of Aldo-keto reductase family 1 member C3. Cell viability and cellular testosterone content were measured in prostate cancer cells. Aido-keto reductase family 1 member C3 mRNA and protein level were detected by RT-PCR and Western bolt analyses, respectively. Computer analysis with AutoDock Tools explored the molecular interaction of berberine with Aldo-keto reductase family 1 member C3. We found that berberine inhibited 22Rvl cells proliferation and decreased cellular testosterone formation in a dose-dependent manner. Berberine inhibited Aldo-keto reductase family I member C3 enzyme activity, rather than influenced mRNA and protein expressions. Molecular docking study demonstrated that berberine could enter the active center of Aldo-keto reductase family 1 member C3 and form π-π interaction with the amino-acid residue Phe306 and Phe311. In conclusion, the structural interaction of berberine with Aldo-keto reductase family 1 member C3 is attributed to the suppression of Aldo-keto reductase family I member C3 enzyme activity and the inhibition of 22Rvl prostate cancer cell growth by decreasing the intfacellular androgen synthesis. Our result provides the experimental basis for the design, research, and development of AKRlC3 inhibitors using berberine as the lead compound.

Quantitative Evaluation of Aldo-keto Reductase Expression in Hepatocellular Carcinoma (HCC) Cell Lines

The involvement of aldo-keto reductases （AKRs） in tumorigenesis is widely reported, but their roles in the pathological process are not generally recognized due to inconsistent measure- ments of their expression. To overcome this problem, we simultaneously employed real-time PCR to examine gene expression and multiple reaction monitoring （MRM） of mass spectrometry （MS） to examine the protein expression of AKRs in five different hepatic cell lines. These include one rela- tively normal hepatic cell line, L-02, and four hepatocellular carcinoma （HCC） cell lines, HepG2, HUH7, BEL7402 and SMMC7721. The results of real-time PCR showed that expression of genes encoding the AKR1C family members rather than AKR1A and AKR1B was associated with tumor, and most of genes encoding AKRs were highly expressed in HUH7. Similar observations were obtained through MRM. Different from HUH7, the protein abundance of AKR1A and AKR1B was relatively consistent among the other four hepatic cell lines, while protein expression of AKR1C varied significantly compared to L-02. Therefore, we conclude that the abundant distri- bution of AKR 1C proteins is likely to be associated with liver tumorigenesis, and the AKR expres- sion status in HuH7 is completely different from other liver cancer cell lines. This study, for the first time, provided both overall and quantitative information regarding the expression of AKRs at both mRNA and protein levels in hepatic cell lines. Our observations put the previous use of AKRs as a biomarker into question since it is only consistent with our data from HUH7. Furthermore, the data presented herein demonstrated that quantitative evaluation and comparisons within a protein fam- ily at both mRNA and protein levels were feasible using current techniques.

Study of Aldo-keto Reductase 1C3 Inhibitor with Novel Framework for Treating Leukaemia Based on Virtual Screening and In vitro Biological Activity Testing

Aldo-keto reductase 1C3(AKR1C3)is a potential target for the treatment of acute myeloid leukaemia and T-cell acute lymphoblastic leukaemia.In this study,pharmacophore models,molecular docking and virtual screening of target prediction were used to find a potential AKR1C3 inhibitor.Firstly,eight bacteriocin derivatives(Z1-Z8)were selected as training sets to construct 20 pharmacophore models.The best pharmacophore model MODEL_016 was obtained by Decoy test(the enrichment degree was 21.5117,and the fitting optimisation degree was 0.9668).Secondly,MODEL_016 was used for the virtual screening of ZINC database.Thirdly,the hit 83256 molecules were docked into the AKR1C3 protein.Compared to the total scores and interactions between compounds and protein,16532 candidate compounds with higher docking scores and interactions with important residues PHE306 and TRP227 were screened.Lastly,eight compounds(A1-A8)that had good absorption,distribution,metabolism,excretion and toxicity(ADMET)properties were obtained by target prediction.Compounds A3 and A7 with high total score and good target prediction results were selected for in vitro biological activity test,whose IC_(50) values were 268.3 and 88.94µmol/L,respectively.The results provide an important foundation for the discovery of novel AKR1C3 inhibitors.The research methods used in this study can also provide important references for the research and development of new drugs.

Astragalin attenuates diabetic cataracts via inhibiting aldose reductase activity in rats

AIM:To investigate the aldose reductase(AR)inhibition capacity of astragalin(AST)against streptozoticin-induced diabetic cataracts(DCs)in rats.METHODS:Ex vivo investigations were conducted by treating the lens of a goat placed for 72h in artificial aqueous humor(AAH)of pH 7.8 at room temperature with cataract-causing substance(55 mmol/L of galactose)and in vivo studies were performed on rats via induction with streptozotocin.AST was administered at different dose levels and scrutinize for DC activity.RESULTS:In diabetic rats,AST improved the body weight,blood insulin,and glucose as well as the levels of galactitol in a dose-dependent way,other biochemical parameters i.e.inflammatory mediators and cytokines,and also suppress AR activity.The level of the antioxidant parameters such as superoxide dismutase(SOD),catalase(CAT),and glutathione(GSH)activity were also altered on a diabetic lens after the administration of the AST.CONCLUSION:AST protects against lens opacification to avoid cataracts and polyols formation,indicating that it could be used as a potential therapeutic agent for diabetes.

Primary 4-3-oxosteroid 5β-reductase deficiency:Two cases in China

Aldo-keto reductase 1D1(AKR1D1) deficiency,a rare but life-threatening form of bile acid deficiency,has not been previously described in China.Here,we describe the first two primary 4-3-oxosteroid 5β-reductase deficiency patients in China's Mainland diagnosed by fast atom bombardment-mass spectroscopy of urinary bile acids and confirmed by genetic analysis.A high proportion of atypical 3-oxo-4-bile acids in the urine indicated a deficiency in 4-3-oxosteroid 5β-reductase.All of the coding exons and adjacent intronic sequence of the AKR1D1 gene were sequenced using peripheral lymphocyte genomic DNA of two patients and one of the patient's parents.One patient exhibited compound heterozygous mutations:c.396C>A and c.722A>T,while the other was heterozygous for the mutation c.797G>A.Based on these mutations,a diagnosis of primary 4-3-oxosteroid 5β-reductase deficiency could be confirmed.With ursodeoxycholic acid treatment and fat-soluble vitamin supplements,liver function tests normalized rapidly,and the degree of hepatomegaly was markedly reduced in both patients.

Cloning and Expression Analysis of Two Wheat cDNAs Encoding Cinnamoyl-CoA Reductase

Cinnamoyl-CoA reductase (CCR) is responsible for the first committed reaction in monolignol biosynthesis, which diverts phenylpropanoid-derived metabolites into the biosynthesis of lignin. To gain a better understanding of the lion biosynthesis in wheat development, two cDNAs encoding CCR were identified from wheat (Triticum aestivum L. cv. H4564). DNA sequence analyses indicated that the two cDNAs represent two classes of CCR. RT-PCR and Northern blot hybridization demonstrated that one of them, W-cr6, was expressed actively in stem and leaf tissue, the other one, W-cr19, was expressed in root and stem tissue. The results suggested that there are at least two genes encoded for CCR existing in wheat genome.

Cloning and Bioinformatic Analysis of Cinnamoyl-CoA Reductase Gene (CCR) from Pennisetum purpureum

[Objective] The aim was to clone the cDNA and DNA sequences of the CCR （Cinnamoyl-CoA reductase） gene which involves in lignin biosynthesis, from Pennisetum purpureum, and to make comprehensive analysis on these sequences. [Method] CCR sequences were cloned from P. purpureum by using conventional RT-PCR and RACE （Rapid Amplification of cDNA Ends） methods; and the bioinformatic analyses of the CCR were conducted by means of NCBI, ProtParam ProtScale, TMHMM, TargetP, SignalP, Pfam20.0, Prosite, Swiss-Model, ClustalW2, DNAman, DNAstar and MEGA5. [Result] The cloned PpCCR （P. purpureum CCR） cDNA sequence was 1 316 bp, including a 1 110 bp ORF and 206 bp 3’-UTR. The cloned DNA sequence from PpCCR was 6 133 bp in full-length, containing five exons and four introns. Bioinformatic analysis indicated that PpCCR encoded a polypeptide of 369 amino acids, the secondary structure of which was primarily composed of random coil and α-helix, belonging to NAD-dependent epimerase/dehydratase family, and its co-factor binding sites and substrate binding sites were highly conserved. [Conclusion] DNA and cDNA sequences of CCR gene were obtained from P. purpureum, which had the typical characteristics of other homologous genes. The obtained bioinformatic data provided theoretical references for the further analysis of CCR and better application of P. purpureum in the future.

多枝赖草Glutathione Reductase基因克隆及胁迫表达分析

为了获得完整的谷胱甘肽还原酶基因序列,根据已克隆到的谷胱甘肽还原酶cDNA片段设计引物,利用RACE扩增获得了基因全长序列,应用Southern印迹杂交法分析基因存在状态,Northern印迹杂交法研究基因表达情况.结果表明,该基因全长1580 bp,含一个1 140 bp的开放阅读框架,编码380个氨基酸,与其它植物谷胱甘肽还原酶氨基酸序列的同源性在77%-92%之间;Southern杂交表明该基因有一个拷贝;Northern杂交表明在逆境胁迫下GR基因表达加强.

Nitrate reductase activity and its diurnal variation rhythm for Camptotheca acuminata seedlings

Nitrate reductase activity (NRA) in different plant organs and leaves in different positions of Camptotheca acuminata seedlings was determined by an In vivo assay, the diurnal variation rhythm of NRA in leaves of different positions was observed,and the correlations between leaf NRA, leaf area and lamina mass per unit area (LMA) were also examined. The results showed that NRA in the leaf was significantly highest, compared with that in other organs such as roots, stems and leaves. In this experiment, the 10 leaves were selected from the apex to the base of the seedlings in order. The different NRA occurred obviously in leaves of different positions of C. acuminata seedlings from the apex to the base, and NRA was higher in the 4th-6th leaves.The diurnal change rhythm of leaf NRA showed a one peak curve, and maximum NRA value appeared at about midday (at 12:30 or so). No obvious correlations between NRA and leaf area or lamina mass per unit area were observed. This study offered scientific foundation for the further research on nitrogen metabolism of C. acuminata.

油菜素内酯合成酶(Steroid 5α-Reductase)基因的超量表达对毛白杨生长的影响

将棉花Steroid 5α-reductase基因(DET2)超量表达载体导入毛白杨中,观察其对毛白杨生长和芽休眠的影响。结果表明,超量表达DET2基因的毛白杨茎高度、直径生长和不定根的生长增强,芽的休眠破除提前。

Dynamic Changes of Nitrate Reductase Activity within 24 Hours

[Objective] The research aimed to study the circadian rhythm of nitrate re- ductase activity （NRA） in plant. [Method] The wheat plants at heading stage were used as the materials for the measurement of dynamic changes of nitrate reductase activity （NRA） within 24 h under the conditions of constant high temperature. [Resulti The fluctuation of NRA in wheat changed greatly from 20：00 pm to 11：00 am. The enzyme activity remained constant, but at 14：00 the enzyme activity was the high- est, higher than all the other time points except the enzyme activity measured at11：00. The enzyme activity was the lowest of 17：00, which was lower than all the other time points except the enzyme activity measured at 2：00. [Conclusion] There were autonomous rhythm changes of NRA in wheat in a certain degree.

Single nucleotide polymorphism C677T in the methylenetetrahydrofolate reductase gene might be a genetic risk factor for infertility for Chinese men with azoospermia or severe oligozoospermia

Aim： To analyze the distribution of the single nucleotide polymorphism （SNP） C677T in the methylenetetrahydrofolate reductase （MTHFR） gene in 355 infertile Chinese patients with idiopathic azoospermia or severe oligozoospermia and 252 fertile Chinese men as controls to explore the possible association of the SNP and male infertility. Methods： Using the polymerase chain reaction （PCR）-restriction fragment length polymorphism technique, the allele and genotype distribution of SNP C677T in the MTHFR gene were investigated in both patients and controls. Results： The frequencies of allele T （40.9% vs 30.4%, P = 0.002, odds ration [OR] = 1.58, 95% confidence interval [CI]： 1.24-2.02） and mutant homozygote （TT） （18.3% vs. 11.5%, P = 0.023, OR = 1.72, 95% CI： 1.07-2.76） as well as carrier with allele （TT ＋ CT） （63.4% vs. 49.2%, P = 0.0005, OR = 1.79, 95% CI： 1.29-2.48） in infertile patients were significantly higher than those in controls. After patient stratification, the significant differences in distribution of the SNP between each patient subgroup and control group still remained. Conclusion： Our findings indicate that there is an association of SNP C677T in the MTHFR gene with male infertility, suggesting that this polymorphism might be a genetic risk factor for male infertility in Chinese men.

Influences of Mo on Nitrate Reductase, Glutamine Synthetase and Nitrogen Accumulation and Utilization in Mo-Efficient and Mo-Inefficient Winter Wheat Cultivars

The objective is to study whether the accumulation and utilization of plant N are controlled by Mo status in winter wheat cultivars. Mo-efficient cultivar 97003 （eft） and Mo-inefficient cultivar 97014 （ineff） were grown in severely Mo-deficient acidic soil （Tamm-reagent-extractable Mo 0.112 mg kg^-1） with （＋Mo） and without （-Mo） the application of 0.13 mg kg^-1 Mo. The accumulation and use efficiency of plant total N were significantly higher in ＋Mo than that in -Mo and in eft than that in ineff under Mo deficiency. N use efficiency was remarkably higher in maturity but it was forwarded to jointing stage after Mo supply, thus indicating that Mo supply promoted the N use efficiency besides N uptake and eff was efficient in N uptake and utilization. The overall activity of nitrate reductase （NR, EC 1.6.6.1） was significantly higher in ＋Mo than in -Mo and ratio of ＋Mo/-Mo was even to 14.8 at filleting stage for ineff. Activity of glutamine synthetase （GS, EC 6.3.1.2） was significantly lower in ＋Mo than in -Mo. Concentration of nitrate and glutamate were also significantly lower in ＋Mo than in -Mo, thus provided evidences for enhancing N use efficiency by Mo supply. Activities of NR and GS were significantly higher and concentrations of nitrate and glutamate were significantly lower in eff than ineff under Mo deficiency, thus indicated eff was more efficient in N reduction and utilization. It is therefore concluded that Mo could promote N accumulation and utilization in winter wheat which was directly related to NR and feedback regulated by GS. Higher Mo status also results in higher accumulation and utilization of plant N in eft.

Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer susceptibility

AIM: To identify the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and gastric cancer (GC) susceptibility.

Differential expression of 5-alpha reductase sozymes in the prostate and its clinical implications

The development of human benign or malignant prostatic diseases is closely associated with androgens, primarily testosterone （T） and dihydrotestosterone （DHT）. T is converted to DHT by 5-alpha reductase （5-AR） isozymes. Differential expression of 5-AR isozymes is observed in both human benign and malignant prostatic tissues. 5-AR inhibitors （5-ARI） are commonly used for the treatment of benign prostatic hyperplasia （BPH） and were once promoted as chemopreventive agents for prostate cancer （PCa）. This review discusses the role of the differential expression of 5-AR in the normal development of the human prostate and in the pathogenesis and progression of BPH and PCa.