Cadmium-induced up-regulation of aldo-keto reductase 1C3 expression in human nasal septum carcinoma RPMI-2650 cells: Involvement of reactive oxygen species and phosphatidylinositol 3-kinase/Akt

AKR1C3 mediates gastric cancer cell invasion and metastasis via the AKT and JNK/p-NF-κB signaling pathways

Gastric cancer (GC) is globally recognized as the fifth most common cancer and the third leading cause of cancer-related mortality. Early metastasis in GC significantly contributes to its high mortality and unfavorable prognosis. However, the underlying mechanisms of this phenomenon remain largely unexplored. Among the various factors involved, AKR1C3 has emerged as a crucial component in the pathways of tumorigenesis and metastasis across multiple cancer types. Yet, the precise significance of AKR1C3 in GC patients' prognosis and its role in GC progression remain elusive. This study illuminated the significant downregulation of AKR1C3 in GC tissues, linking it to an aggressive phenotype and poor prognosis. Interestingly, while AKR1C3 overexpression did not affect the proliferation of GC cells, it significantly inhibited their ability to invade and metastasize. The underlying mechanism appears to involve AKR1C3's inhibition of the p-JNK pathway, which leads to reduced phosphorylation of IKKα/β and IKBα, lowering p-NF-κB levels and hindering its movement into the nucleus, thereby stifling the epithelial-mesenchymal transition (EMT) process in GC cells. These insights reveal AKR1C3's tumor-suppressive effects in GC and suggest its potential as a diagnostic and prognostic biomarker, offering new avenues for targeted therapies in gastric cancer management.

AKR1C3 in carcinomas: from multifaceted roles to therapeutic strategies

Aldo-Keto Reductase Family 1 Member C3 (AKR1C3), also known as type 5 17β-hydroxysteroid dehydrogenase (17β-HSD5) or prostaglandin F (PGF) synthase, functions as a pivotal enzyme in androgen biosynthesis. It catalyzes the conversion of weak androgens, estrone (a weak estrogen), and PGD2 into potent androgens (testosterone and 5α-dihydrotestosterone), 17β-estradiol (a potent estrogen), and 11β-PGF2α, respectively. Elevated levels of AKR1C3 activate androgen receptor (AR) signaling pathway, contributing to tumor recurrence and imparting resistance to cancer therapies. The overexpression of AKR1C3 serves as an oncogenic factor, promoting carcinoma cell proliferation, invasion, and metastasis, and is correlated with unfavorable prognosis and overall survival in carcinoma patients. Inhibiting AKR1C3 has demonstrated potent efficacy in suppressing tumor progression and overcoming treatment resistance. As a result, the development and design of AKR1C3 inhibitors have garnered increasing interest among researchers, with significant progress witnessed in recent years. Novel AKR1C3 inhibitors, including natural products and analogues of existing drugs designed based on their structures and frameworks, continue to be discovered and developed in laboratories worldwide. The AKR1C3 enzyme has emerged as a key player in carcinoma progression and therapeutic resistance, posing challenges in cancer treatment. This review aims to provide a comprehensive analysis of AKR1C3's role in carcinoma development, its implications in therapeutic resistance, and recent advancements in the development of AKR1C3 inhibitors for tumor therapies.

Knockdown of AKR1C3 Promoted Sorafenib Sensitivity Through Inhibiting the Phosphorylation of AKT in Hepatocellular Carcinoma

Background

Sorafenib, which can induce ferroptosis, is a multikinase inhibitor for enhancing survival in advanced hepatocellular carcinoma (HCC). However, a considerable challenge for the treatment of HCC is sorafenib resistance. Therefore, targeting the relationship between sorafenib resistance and ferroptosis genes may provide a novel approach for the treatment of HCC.

Materials and Methods

We analyzed the gene expression and clinicopathological factors from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC), International Cancer Genome Consortium (ICGC), and Gene Expression Omnibus (GEO) databases (GSE109211/GSE62813). The statistical analysis was conducted in R. Cell proliferation was assayed by MTT, cell colony-forming assay, and wound healing assay. Immunofluorescence assay and Western blot were used to evaluate the expression of AKT.

Results

Many ferroptosis-related genes were upregulated in the sorafenib-resistant group. Aldo-keto reductase 1C3 (AKR1C3) was highly expressed in sorafenib-resistant patients, and the high expression of AKR1C3 was associated with the poor prognosis of patients from the TCGA and ICGC databases. MTT and colony-forming assays showing AKR1C3 overexpression enhanced the proliferation of HCC cells and acute sorafenib resistance. Knockdown of AKR1C3 inhibited the proliferation of HCC cells and increased the drug sensitivity of sorafenib. Immunofluorescence assay and Western blot proved that AKR1C3 promoted the phosphorylation of AKT.

Conclusion

AKR1C3 can induce sorafenib resistance through promoting the phosphorylation of AKT in HCC. AKR1C3 inhibitors may be used in conjunction with sorafenib to become a better therapeutic target for HCC.

Cadmium-Associated Molecular Signatures in Cancer Cell Models

The exposure of cancer cells to cadmium and its compounds is often associated with the development of more malignant phenotypes, thereby contributing to the acceleration of tumor progression. It is known that cadmium is a transcriptional regulator that induces molecular reprogramming, and therefore the study of differentially expressed genes has enabled the identification and classification of molecular signatures inherent in human neoplastic cells upon cadmium exposure as useful biomarkers that are potentially transferable to clinical research. This review recapitulates selected studies that report the detection of cadmium-associated signatures in breast, gastric, colon, liver, lung, and nasopharyngeal tumor cell models, as specifically demonstrated by individual gene or whole genome expression profiling. Where available, the molecular, biochemical, and/or physiological aspects associated with the targeted gene activation or silencing in the discussed cell models are also outlined.

Molecular Mechanism of Cellular Oxidative Stress Sensing by Keap1

The Keap1-Nrf2 system plays a central role in the oxidative stress response; however, the identity of the reactive oxygen species sensor within Keap1 remains poorly understood. Here, we show that a Keap1 mutant lacking 11 cysteine residues retains the ability to target Nrf2 for degradation, but it is unable to respond to cysteine-reactive Nrf2 inducers. Of the 11 mutated cysteine residues, we find that 4 (Cys226/613/622/624) are important for sensing hydrogen peroxide. Our analyses of multiple mutant mice lines, complemented by MEFs expressing a series of Keap1 mutants, reveal that Keap1 uses the cysteine residues redundantly to set up an elaborate fail-safe mechanism in which specific combinations of these four cysteine residues can form a disulfide bond to sense hydrogen peroxide. This sensing mechanism is distinct from that used for electrophilic Nrf2 inducers, demonstrating that Keap1 is equipped with multiple cysteine-based sensors to detect various endogenous and exogenous stresses.

Application of RPMI 2650 as a cell model to evaluate solid formulations for intranasal delivery of drugs

During the development of intranasal drug delivery systems for local/systemic effect or brain targeting, it is necessary to assess its cytotoxicity and drug transport through nasal epithelium. In order to avoid animal experiments or the use of excised tissues, in vitro cell models, such as RPMI 2650 cells, are being preferred during recent years. Nevertheless, the deposition of solid formulations into nasal cell layers with further transepithelial transport rate of drugs has been poorly studied or reported. Thus, the purpose of this work is to further investigate RPMI 2650 cell line as an effective alternative to animal tissues for solid drug-loaded formulations cytotoxicity and drug permeation studies in order to become an option as a tool for drug discovery. Furthermore, we wanted to determine the extent to which the administration of drugs in particulate forms would differ in relation to the permeability of the same compounds applied as solutions. RPMI 2650 cells were cultured in submersed or at air-liquid interface conditions and characterized regarding transepithelial electrical resistance (TEER) and production of mucus. Pure ketoprofen (used as model compound) and five formulations loaded with same drug, namely solid lipid particles (Gelucire 43/01™), structured lipid particles (Gelucire 43/01™:Glyceryl monooleate) and aerogel microparticles (Alginate, Alginate:Pectin, Alginate:Carrageenan), were evaluated with RPMI 2650 model in terms of cytotoxicity and permeability of drug (applied as solution, dispersion or powder+buffer). RPMI 2650 cells were capable to grow in monolayer and multilayer, showing the same permeability as excised human nasal mucosa for sodium fluorescein (paracellular marker), with analogous TEER values and production of mucus, as referred by other authors. None of the powders showed cytotoxicity when applied to RPMI 2650 cells. Regarding permeation of drug through cell layers, not only the form of application of powders but also their physical and chemical properties affected the final permeation of active pharmaceutical ingredient. Aerogel microparticles administered directly to the cell layer (powder+buffer) exhibited the highest permeation-enhancing effect compared to the pure drug, which can be attributed to the mucoadhesive properties of the materials composing the carriers, proving to be an attractive formulation for nasal drug delivery. According to these results, RPMI 2650 showed to be a promising alternative to ex vivo or in vivo nasal models for cytotoxicity and evaluation of drug permeability of nasal drug-loaded formulations.

Role and mechanism of insulin-like growth factor 2 on the proliferation of human trophoblasts in vitro

AIM

To study the effect and relevant molecular mechanisms of insulin-like growth factor 2 (IGF2) on the proliferative activity of first trimester human trophoblasts in vitro.

MATERIALS AND METHODS

Extravillous cytotrophoblasts (EVCTs) were isolated and cultured. Cells were cultured with IGF2 at different concentrations and the proliferative activity was measured using methyl thiazolyl tretrazolium assay. LY294002, a specific inhibitor of the phosphatidylinositol 3-kinase (PI3K), was used as an indirect indicator of the possible involvement of the PI3K signal pathway. We tested the apoptosis rate using flow cytometry technology influenced by IGF2 with or without LY294002. The effects of IGF2 on phosphorylation of key cell signaling proteins (protein kinase B [AKT] and phosphorylated AKT) in EVCTs were examined by western blot analysis with or without LY294002.

RESULTS

There was a significant difference between the IGF2 group above 10 nM and the control group (P < 0.05). LY294002 (10 μM) not only inhibited the proliferative activity of EVCT, but also significantly restrained the effect on EVCTs (P < 0.05). In vitro data proved that the apoptosis rate decreased when IGF2 was added (P < 0.05), but increased when inhibited by LY294002 (P < 0.05). After incubation with IGF2, AKT phosphorylation increased compared to incubation without IGF2 treatment (P < 0.05). LY294002 activation reduced the IGF2-induced effects (P < 0.05).

CONCLUSIONS

Our data suggest that IGF2 enhances EVCT proliferation and inhibits apoptosis. The PI3K/AKT pathway is an important signaling pathway in the proliferative activity of EVCTs on early human pregnancy in vitro.

A novel fluorometric assay for aldo-keto reductase 1C3 predicts metabolic activation of the nitrogen mustard prodrug PR-104A in human leukaemia cells

Aldo-keto reductase 1C3 (AKR1C3, EC 1.1.1.188) metabolises steroid hormones, prostaglandins and xenobiotics, and activates the dinitrobenzamide mustard prodrug PR-104A by reducing it to hydroxylamine PR-104H. Here, we describe a functional assay for AKR1C3 in cells using the fluorogenic probe coumberone (a substrate for all AKR1C isoforms) in conjunction with a specific inhibitor of AKR1C3, the morpholylurea SN34037. We use this assay to evaluate AKR1C3 activity and PR-104A sensitivity in human leukaemia cells. SN34037-sensitive reduction of coumberone to fluorescent coumberol correlated with AKR1C3 protein expression by immunoblotting in a panel of seven diverse human leukaemia cell lines, and with SN34037-sensitive reduction of PR-104A to PR-104H. SN34037 inhibited aerobic cytotoxicity of PR-104A in high-AKR1C3 TF1 erythroleukaemia cells, but not in low-AKR1C3 Nalm6 pre-B cell acute lymphocytic leukaemia (B-ALL) cells, although variation in PR-104H sensitivity confounded the relationship between AKR1C3 activity and PR-104A sensitivity across the cell line panel. AKR1C3 mRNA expression showed wide variation between leukaemia patients, with consistently higher levels in T-ALL than B-ALL. In short term cultures from patient-derived paediatric ALL xenografts, PR-104A was more potent in T-ALL than B-ALL lines, and PR-104A cytotoxicity was significantly inhibited by SN34037 in T-ALL but not B-ALL. Overall, the results demonstrate that SN34037-sensitive coumberone reduction provides a rapid and specific assay for AKR1C3 activity in cells, with potential utility for identifying PR-104A-responsive leukaemias. However, variations in PR-104H sensitivity indicate the need for additional biomarkers for patient stratification.

Oxidative stress and mitogen-activated protein kinase pathways involved in cadmium-induced BRL 3A cell apoptosis

In this study, BRL 3A cells were treated with different Cd concentrations (0, 10, 20, and 40 μmol/L) for 12 h and preincubated with or without N-acetyl-L-cysteine (NAC) (2 mmol/L) for 30 min, and cells were treated with Cd (0 and 20 μmol/L), pretreated with p38 inhibitor (SB203580), JNK (c-Jun NH2-terminal kinases) inhibitor (SP600125), and extracellular signal-regulated kinase (ERK) inhibitor (U0126) for 30 min, and then treated with 20 μmol/L Cd for 12 h. Cd decreased cell viability, SOD, and GSH-Px activity in a concentration-dependent manner. Increased MDA level, ROS generation, nuclear condensation, shrinkage, and fragmentation in cell morphology were inhibited by NAC. Cd-induced apoptosis was attenuated by pretreatment with SB203580, SP600125, and U0126. The results of western blot showed that NAC preincubation affected Cd-activated MAPK pathways, p38 and ERK phosphorylation. Cd treatment elevated the mRNA levels of Bax and decreased the mRNA levels of Bcl-2, respectively. The same effect was found in their protein expression levels. These results suggest that oxidative stress and MAPK pathways participate in Cd-induced apoptosis and that the balance between pro- and antiapoptotic genes (Bax and Bcl-2) is important in Cd-induced apoptosis.

Proteomic analysis on N, N'-dinitrosopiperazine-mediated metastasis of nasopharyngeal carcinoma 6-10B cells

BACKGROUND

Nasopharyngeal carcinoma (NPC) has a high metastatic feature. N,N'-Dinitrosopiperazine (DNP) is involved in NPC metastasis, but its mechanism is not clear. The aim of this study is to reveal the pathogenesis of DNP-involved metastasis. 6-10B cells with low metastasis are from NPC cell line SUNE-1, were used to investigate the mechanism of DNP-mediated NPC metastasis.

RESULTS

6-10B cells were grown in DMEM containing 2H4-L-lysine and 13C 6 15 N4-L-arginine or conventional L-lysine and L-arginine, and identified the incorporation of amino acid by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Labeled 6-10B cells were treated with DNP at 0 -18 μM to establish the non-cytotoxic concentration (NCC) range. NCC was 0 -10 μM. Following treatment with DNP at this range, the motility and invasion of cells were detected in vitro, and DNP-mediated metastasis was confirmed in the nude mice. DNP increased 6-10B cell metastasis in vitro and vivo. DNP-induced protein expression was investigated using a quantitative proteomic. The SILAC-based approach quantified 2698 proteins, 371 of which showed significant change after DNP treatment (172 up-regulated and 199 down-regulated proteins). DNP induced the change in abundance of mitochondrial proteins, mediated the status of oxidative stress and the imbalance of redox state, increased cytoskeletal protein, cathepsin, anterior gradient-2, and clusterin expression. DNP also increased the expression of secretory AKR1B10, cathepsin B and clusterin 6-10B cells. Gene Ontology and Ingenuity Pathway analysis showed that DNP may regulate protein synthesis, cellular movement, lipid metabolism, molecular transport, cellular growth and proliferation signaling pathways.

CONCLUSION

DNP may regulate cytoskeletal protein, cathepsin, anterior gradient-2, and clusterin expression, increase NPC cells motility and invasion, is involved NPC metastasis.

Regulation of aldo-keto reductases in human diseases

The aldo-keto reductases (AKRs) are a superfamily of NAD(P)H-linked oxidoreductases, which reduce aldehydes and ketones to their respective primary and secondary alcohols. AKR enzymes are increasingly being recognized to play an important role in the transformation and detoxification of aldehydes and ketones generated during drug detoxification and xenobiotic metabolism. Many transcription factors have been identified to regulate the expression of human AKR genes, which could have profound effects on the metabolism of endogenous mediators and detoxication of chemical carcinogens. This review summarizes the current knowledge on AKR regulation by transcription factors and other mediators in human diseases.

Four-and-a-half-LIM protein 1 down-regulates estrogen receptor α activity through repression of AKT phosphorylation in human breast cancer cell

The Four-and-a-half LIM protein 1 (FHL-1) is a member of LIM-only protein family. It plays important roles in proliferation and apoptosis regulation of certain hepatocellular carcinoma and human breast cancer. Estrogen receptor α (ERα) is involved in the development and progression of human breast cancer. IGF/PI3K/AKT signaling pathway also plays certain roles in the program and regulation of human breast cancer and ovary cancer. However, the biological function of FHL-1 in regulation of human breast cancer and in the cross-talk of estrogen and IGF signaling pathway remains largely unknown. In this paper, we show that FHL-1 protein interacts with ERα and AKT. FHL-1 represses the translation and transcription of estrogen receptor-responsive genes through down-regulating AKT activation. In addition, FHL-1 is not only an ERα-interacting co-regulation protein, but also decreases the phosphorylation of AKT and ERα. Depression of endogenous FHL-1 by FHL-1 targeted small interfering RNA enhances the expression of these proteins and phosphorylation of AKT and ERα. These data suggest that FHL-1 may regulate ER signaling function through regulation of AKT activation besides the physical and functional interaction with ERα. By establishing a linkage role of the FHL-1 between the estrogen ERα signaling pathway and IGF/PI3K/AKT signaling pathway, this study identifies that FHL-1 proteins may be a useful molecular target for human breast cancer therapy.