Modulation of Nqo1 activity intercepts anoikis resistance and reduces metastatic potential of hepatocellular carcinoma

Sphingosine kinase 2 and p62 regulation are determinants of sexual dimorphism in hepatocellular carcinoma

OBJECTIVE

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality, and its incidence is increasing due to endemic obesity. HCC is sexually dimorphic in both humans and rodents with higher incidence in males, although the mechanisms contributing to these correlations remain unclear. Here, we examined the role of sphingosine kinase 2 (SphK2), the enzyme that regulates the balance of bioactive sphingolipid metabolites, sphingosine-1-phosphate (S1P) and ceramide, in gender specific MASH-driven HCC.

METHODS

Male and female mice were fed a high fat diet with sugar water, a clinically relevant model that recapitulates MASH-driven HCC in humans followed by physiological, biochemical cellular and molecular analyses. In addition, correlations with increased risk of HCC recurrence were determined in patients.

RESULTS

Here, we report that deletion of SphK2 protects both male and female mice from Western diet-induced weight gain and metabolic dysfunction without affecting hepatic lipid accumulation or fibrosis. However, SphK2 deficiency decreases chronic diet-induced hepatocyte proliferation in males but increases it in females. Remarkably, SphK2 deficiency reverses the sexual dimorphism of HCC, as SphK2-/- male mice are protected whereas the females develop liver cancer. Only in male mice, chronic western diet induced accumulation of the autophagy receptor p62 and its downstream mediators, the antioxidant response target NQO1, and the oncogene c-Myc. SphK2 deletion repressed these known drivers of HCC development. Moreover, high p62 expression correlates with poor survival in male HCC patients but not in females. In hepatocytes, lipotoxicity-induced p62 accumulation is regulated by sex hormones and prevented by SphK2 deletion. Importantly, high SphK2 expression in male but not female HCC patients is associated with a more aggressive HCC differentiation status and increased risk of cancer recurrence.

CONCLUSIONS

This work identifies SphK2 as a potential regulator of HCC sexual dimorphism and suggests SphK2 inhibitors now in clinical trials could have opposing, gender-specific effects in patients.

Human NQO1 as a Selective Target for Anticancer Therapeutics and Tumor Imaging

Human NAD(P)H-quinone oxidoreductase1 (HNQO1) is a two-electron reductase antioxidant enzyme whose expression is driven by the NRF2 transcription factor highly active in the prooxidant milieu found in human malignancies. The resulting abundance of NQO1 expression (up to 200-fold) in cancers and a barely detectable expression in body tissues makes it a selective marker of neoplasms. NQO1 can catalyze the repeated futile redox cycling of certain natural and synthetic quinones to their hydroxyquinones, consuming NADPH and generating rapid bursts of cytotoxic reactive oxygen species (ROS) and H2O2. A greater level of this quinone bioactivation due to elevated NQO1 content has been recognized as a tumor-specific therapeutic strategy, which, however, has not been clinically exploited. We review here the natural and new quinones activated by NQO1, the catalytic inhibitors, and the ensuing cell death mechanisms. Further, the cancer-selective expression of NQO1 has opened excellent opportunities for distinguishing cancer cells/tissues from their normal counterparts. Given this diagnostic, prognostic, and therapeutic importance, we and others have engineered a large number of specific NQO1 turn-on small molecule probes that remain latent but release intense fluorescence groups at near-infrared and other wavelengths, following enzymatic cleavage in cancer cells and tumor masses. This sensitive visualization/quantitation and powerful imaging technology based on NQO1 expression offers promise for guided cancer surgery, and the reagents suggest a theranostic potential for NQO1-targeted chemotherapy.

Targeting anoikis resistance as a strategy for cancer therapy

Anoikis, known as matrix detachment-induced apoptosis or detachment-induced cell death, is crucial for tissue development and homeostasis. Cancer cells develop means to evade anoikis, e.g. anoikis resistance, thereby allowing for cells to survive under anchorage-independent conditions. Uncovering the mechanisms of anoikis resistance will provide details about cancer metastasis, and potential strategies against cancer cell dissemination and metastasis. Here, we summarize the principal elements and core molecular mechanisms of anoikis and anoikis resistance. We discuss the latest progress of how anoikis and anoikis resistance are regulated in cancers. Furthermore, we summarize emerging data on selective compounds and nanomedicines, explaining how inhibiting anoikis resistance can serve as a meaningful treatment modality against cancers. Finally, we discuss the key limitations of this therapeutic paradigm and possible strategies to overcome them. In this review, we suggest that pharmacological modulation of anoikis and anoikis resistance by bioactive compounds could surmount anoikis resistance, highlighting a promising therapeutic regimen that could be used to overcome anoikis resistance in cancers.

Liver function indicators and risk of hepatocellular carcinoma: a bidirectional mendelian randomization study

Observational studies have shown an association between liver dysfunction and hepatocellular carcinoma (HCC), but the causality relationship between them is unclear. We aimed to determine whether there is a bidirectional causal relationship between liver function indicators (alanine aminotransferase, ALT; aspartate aminotransferase, AST; alkaline phosphatase, ALP; γ-glutamyltransferase, GGT) and HCC. Our two-sample Mendelian randomization (MR) study acquired single nucleotide polymorphisms (SNPs) associated with liver function indicators (ALT, n = 134,182; AST, n = 134,154; GGT, n = 118,309; ALP, n = 105,030) and with HCC (n = 197,611) from publicly available genome-wide association studies (GWAS) of East Asian ancestry in Japan (BioBank Japan, BBJ). Univariable MR analyses were performed to identify whether the genetic evidence of exposure was significantly associated with outcome. Multivariable MR analysis was conducted to estimate the independent effects of exposures on outcome. Univariable MR analysis indicated that the level of ALT, AST, and GGT was the risk factor for HCC incidence. Meanwhile, multivariable MR analysis revealed that AST was an independent risk factor for HCC. The hazard ratio (HR) of the probability of HCC was 3.045 [95% confidence interval (95%CI), 1.697-5.463, p = 0.003] for AST. The results of reverse MR analyses showed that gene-predictive HCC incidence could increase the levels of AST (HR = 1.031, 95%CI: 1.009-1.054, p = 2.52 × 10-4) and ALT (HR = 1.040, 95%CI: 1.019-1.063, p = 0.005). Meanwhile, HCC may be negatively correlated with ALP levels (HR = 0.971, 95%CI: 0.947-0.995, p = 0.018). This study provides evidence to support that genetically predicted higher levels of AST are related to increased risk of HCC, with no strong evidence of a causal effect of genetically predicted ALP, ALP, and GGT on HCC. In addition, genetic predisposition to HCC could influence blood concentration of ALT, AST, and ALP. Thus, this may create a vicious cycle.

Development and validation of multi-omic prognostic signature of anoikis-related genes in liver hepatocellular carcinoma

Liver hepatocellular carcinoma (LIHC) is characterized by high morbidity, rapid progression and early metastasis. Although many efforts have been made to improve the prognosis of LIHC, the situation is still dismal. Inability to initiate anoikis process is closely associated with cancer proliferation and metastasis, affecting patients' prognosis. In this study, a corresponding gene signature was constructed to comprehensively assess the prognostic value of anoikis-related genes (ARGs) in LIHC. Using TCGA-LIHC dataset, the mRNA levels of the differentially expressed ARGs in LIHC and normal tissues were compared by Student t test. And prognostic ARGs were identified through Cox regression analysis. Prognostic signature was established and then externally verified by ICGC-LIRI-JP dataset and GES14520 dataset via LASSO Cox regression model. Potential functions and mechanisms of ARGs in LIHC were evaluated by functional enrichment analyses. And the immune infiltration status in prognostic signature was analyzed by ESTIMATE algorithm and ssGSEA algorithm. Furthermore, ARGs expression in LIHC tissues was validated via qRT-PCR and IHC staining from the HPA website. A total of 97 differentially expressed ARGs were detected in LIHC tissues. Functional enrichment analysis revealed these genes were mainly involved in MAP kinase activity, apoptotic signaling pathway, anoikis and PI3K-Akt signaling pathway. Afterward, the prognostic signature consisting of BSG, ETV4, EZH2, NQO1, PLK1, PBK, and SPP1 had a moderate to high predictive accuracy and served as an independent prognostic indicator for LIHC. The prognostic signature was also applicable to patients with distinct clinical parameters in subgroup survival analysis. And it could reflect the specific immune microenvironment in LIHC, which indicated high-risk group tended to profit from ICI treatment. Moreover, qRT-PCR and IHC staining showed increasing expression of BSG, ETV4, EZH2, NQO1, PLK1, PBK and SPP1in LIHC tissues, which were consistent to the results from TCGA database. The current study developed a novel prognostic signature comprising of 7 ARGs, which could stratify the risk and effectively predict the prognosis of LIHC patients. Furthermore, it also offered a potential indicator for immunotherapy of LIHC.

Identification of a Novel Oxidative Stress- and Anoikis-Related Prognostic Signature and Its Immune Landscape Analysis in Non-Small Cell Lung Cancer

The objective of this study was to identify a kind of prognostic signature based on oxidative stress- and anoikis-related genes (OARGs) for predicting the prognosis and immune landscape of NSCLC. Initially, We identified 47 differentially expressed OARGs that primarily regulate oxidative stress and epithelial cell infiltration through the PI3K-Akt pathway. Subsequently, 10 OARGs related to prognosis determined two potential clusters. A cluster was associated with a shorter survival level, lower immune infiltration, higher stemness index and tumor mutation burden. Next, The best risk score model constructed by prognostic OARGs was the Random Survival Forest model, and it included SLC2A1, LDHA and PLAU. The high-risk group was associated with cluster A and poor prognosis, with a higher tumor mutation burden, stemness index and proportion of M0-type macrophages, and a lower immune checkpoint expression level, immune function score and IPS score. The calibration curve and decision-making curve showed that the risk score combined with clinical pathological characteristics could be used to construct a nomogram for guiding the clinical treatment strategies. Finally, We found that all three hub genes were highly expressed in tumor tissues, and LDHA expression was mainly regulated by has-miR-338-3p, has-miR-330-5p and has-miR-34c-5p. Altogether, We constructed an OARG-related prognostic signature to reveal potential relationships between the signature and clinical characteristics, TME, stemness, tumor mutational burden, drug sensitivity and immune landscape in NSCLC patients.

Non-metabolic enzyme function of PKM2 in hepatocellular carcinoma: A review

Hepatocellular carcinoma (HCC) is one of the most malignant tumors with the highest incidence and mortality in the world, causing a serious burden on society. Pyruvate kinase M2 (PKM2) is one of the principal metabolic enzymes involved in glycolysis. Studies have shown that PKM2 is highly expressed in HCC and can be translocated to the nucleus, where it interacts with various transcription factors and proteins such as hypoxia-inducible factor-1α, sterol regulatory element-binding protein 1a, signal transducer and activator of transcription 3, nuclear factor erythroid 2-like 2 and histone H3, exerting non-metabolic enzyme functions to regulate the cell cycle, proliferation, apoptosis, immune escape, migration, and invasion, as well as HCC angiogenesis and tumor microenvironment. This review is focused on the recent progress of PKM2 interacting with various transcription factors and proteins affecting the onset and development of HCC, as well as natural drugs and noncoding RNA impacting diverse biological functions of liver cancer cells by regulating PKM2 non-metabolic enzyme functions, thereby providing valuable directions for the prognosis improvement and molecular targeted therapy of HCC in the future.

NQO1 drives glioblastoma cell aggressiveness through EMT induction via the PI3K/Akt/mTOR/Snail pathway

Glioblastoma multiforme (GBM) is the most frequent and lethal cancer derived from the central nervous system, of which the mesenchymal (MES) subtype seriously influences the survival and prognosis of patients. NAD(P)H: quinone acceptor oxidoreductase 1 (NQO1) serves an important role in the carcinogenesis and progression of various types of cancer; however, the specific mechanism underlying the regulatory effects of NQO1 on GBM is unclear. Thus, the present study aimed to explore the role and mechanism of NQO1 in GBM progression. The results of bioinformatics analysis and immunohistochemistry showed that high expression of NQO1 was significantly related to the MES phenotype of GBM and shorter survival. In addition, MTT, colony formation, immunofluorescence and western blot analyses, and lung metastasis model experiments suggested that silencing NQO1 inhibited the proliferation and metastasis of GBM cells in vitro and in vivo. Furthermore, western blotting showed that the activity of the PI3K/Akt/mTOR signaling pathway was revealed to be inhibited by downregulation of NQO1 expression, whereas it was enhanced by overexpression of NQO1. Notably, co‑immunoprecipitation and ubiquitination experiments suggested that Snail was considered an important downstream target of NQO1 in GBM cells. Snail knockdown could eliminate the promoting effect of ectopic NQO1 on the proliferation and invasion of GBM cells, and reduce its effects on the activity of PI3K/Akt/mTOR signaling pathway. These results indicated that NQO1 could promote GBM aggressiveness by activating the PI3K/Akt/mTOR signaling pathway in a Snail‑dependent manner, and NQO1 and its relevant pathways may be considered novel targets for GBM therapy.

Development of a prognostic signature based on anoikis-related genes in hepatocellular carcinoma with the utilization of LASSO-cox method

To develop a signature based on anoikis-related genes (ARGs) for predicting the prognosis of patients with hepatocellular carcinoma (HCC), and to elucidate the molecular mechanisms involved. In this study, bioinformatic algorithms were applied to integrate and analyze 777 HCC RNA-seq samples from the cancer genome atlas and international cancer genome consortium repositories. A prognostic signature was developed via the least absolute shrinkage and selection operator-cox regression method. To evaluate the accuracy of the signature in predicting events, multi-type technical means, such as Kaplan-Meier plots, receiver operating characteristic curve analysis, nomogram construction, and univariate and multivariate Cox regression studies were performed. We investigated the underlying molecular biological mechanisms and immune mechanisms of the signature using gene set enrichment analysis and the CIBERSORT R package, respectively. Meanwhile, immunohistochemical staining acquired from the human protein atlas was used to confirm the differential expression levels of hub genes involved in the prognostic signature. We developed an HCC prognostic signature with a collection of 5 ARGs, and the prognostic value was successfully assessed and verified in both the test and validation cohorts. The risk scores calculated by the prognostic signature were proved to be an independent negative prognostic factor for overall survival. A set of nomograms based on risk scores was established and found to be effective in predicting OS. Further investigation of the underlying molecular biological mechanisms and immune mechanisms indicated that the signature may be relevant to metabolic dysregulation and infiltration of gamma delta T cells in the tumor. The survival prognosis of HCC patients can be predicted by the anoikis-related prognostic signature, and it serves as a valuable reference for individualized HCC therapy.

The promoting effect and mechanism of Nrf2 on cell metastasis in cervical cancer

BACKGROUND

Cervical cancer (CC) has poor prognosis and high mortality rate for its metastasis during the disease progression. Epithelial-mesenchymal transition (EMT) and anoikis are initial and pivotal steps during the metastatic process. Although higher levels of Nrf2 are associated with aggressive tumor behaviors in cervical cancer, the detailed mechanism of Nrf2 in cervical cancer metastasis, especially EMT and anoikis, remains unclear.

METHODS

Immunohistochemistry (IHC) was used to examine Nrf2 expression in CC. Wound healing assay and transwell analysis were used to evaluate the migration ability of CC cells. Western blot, qTR-PCR and immunofluorescent staining were used to verify the expression level of Nrf2, the EMT associated markers and anoikis associated proteins. Flow cytometry assays and cell counting were used to detect the apoptosis of cervical cancer cells. The lung and lymph node metastatic mouse model were established for studies in vivo. The interaction between Nrf2 and Snail1 was confirmed by rescue-of-function assay.

RESULTS

When compared with cervical cancer patients without lymph node metastasis, Nrf2 was highly expressed in patients with lymph node metastasis. And Nrf2 was proved to enhance the migration ability of HeLa and SiHa cells. In addition, Nrf2 was positively correlated with EMT processes and negatively associated with anoikis in cervical cancer. In vivo, a xenograft assay also showed that Nrf2 facilitated both pulmonary and lymphatic distant metastasis of cervical cancer. Rescue-of-function assay further revealed the mechanism that Nrf2 impacted the metastasis of CC through Snail1.

CONCLUSION

Our fundings established Nrf2 plays a crucial role in the metastasis of cervical cancer by enhancing EMT and resistance to anoikis by promoting the expression of Snail1, with potential value as a therapeutic candidate.

Antioxidants-related nuclear factor erythroid 2-related factor 2 gene variants associated with HBV-related liver disease

BACKGROUND

Accumulating evidence demonstrated that nuclear factor erythroid 2-related factor 2 (NRF2) expression plays a crucial role in the proliferation, invasion and metastasis of hepatocellular carcinoma (HCC). However, research on the effect of NRF2 genetic polymorphism on the development of chronic hepatitis B (CHB), HBV-related liver cirrhosis (LC) and HCC is still missing.

METHODS

A total of 673 individuals were included in the study and classified into four groups: 110 CHB cases, 86 LC cases, 260 HCC cases, and 217 healthy controls. ​The polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing method were used to detect rs6721961 and rs6726395 polymorphisms.

RESULTS

Patients carrying the T allele in rs6721961 were at a higher risk of HCC than individuals with the G allele compared to CHB patients (OR = 1.561, 95%CI: 1.003-2.430, P = 0.048). The statistically significant differences were also found in the rs6721961 GT genotype (OR = 2.298, 95% CI: 1.282-4.119, P = 0.005) and dominant model (OR = 2.039, 95% CI: 1.184-0.510, P = 0.010). Subgroup analysis also detected a significant association between the rs6721961 T allele and the development of HCC in older subjects (≥ 50 years) (OR = 2.148, 95% CI: 1.208-3.818, P = 0.009). Statistical analysis results indicated that subjects carrying haplotype G-A had a lower risk of HCC (OR = 0.700, 95% CI: 0.508-0.965, P = 0.028).

CONCLUSIONS

For the first time, our findings provide evidence that the NRF2 gene rs6721961 variation is a potential genetic marker of susceptibility to HCC.

Integrated analysis of ferroptosis-related gene signature for overall survival prediction in Asian patients with hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is one of the most prevalent types of cancers in Asia. Accumulating evidence suggests that ferroptosis is a non-apoptotic form of cell death, and has played an important role in cancer biology.

METHODS

Based on the manually curated ferroptosis-related gene set and TCGA-LIHC dataset of Asian patients, we used DESeq2, Kaplan-Meier analysis, and univariate Cox regression to identify differentially expressed ferroptosis-related genes with significantly prognostic capacity. A risk signature was constructed based on the selected genes for predicting the survival of HCC patients in Asia. The survival prediction accuracy was confirmed by the time-dependent receiver operating characteristic (ROC) curve analysis. Gene set variation analysis (GSVA) was used to explore the functional associations of the signature. Ferroptosis potential index (FPI) and xCell algorithm was applied to quantify ferroptosis and immune cell infiltration, respectively. Two independent datasets from the GEO and the ICGC database were used for external validation.

RESULTS

The ferroptosis-related signature could accurately predict the survival outcomes of HCC patients in Asian (p value < 0.0001). We showed that the signature was an independent factor and was beneficial in elevating risk stratification of current clinicopathologic features, such as the amount of alpha-fetoprotein (AFP) and residual tumor classification. Functional characterization showed that critical processes in tumorigenesis belonged to the high-risk groups, for example inflammatory response, which may be the main driver of HCC. The high-risk group had higher FPIs and infiltrations of macrophages and T-helper cells than the low-risk group. Furthermore, two independent cohorts confirmed the prognostic value of our signature.

CONCLUSION

Overall, our results demonstrated potential application of ferroptosis-related genes as independent biomarkers in Asian HCC patients. Targeting ferroptosis may be clinically useful beyond known clinicopathological factors and provide benefit in immunotherapy.

An anoikis-based signature for predicting prognosis in hepatocellular carcinoma with machine learning

Background: Hepatocellular carcinoma (HCC) is a common malignancy with high mortality worldwide. Despite advancements in diagnosis and treatment in recent years, there is still an urgent unmet need to explore the underlying mechanisms and novel prognostic markers. Anoikis has received considerable attention because of its involvement in the progression of human malignancies. However, the potential mechanism of anoikis-related genes (ANRGs) involvement in HCC progression remains unclear. Methods: We use comprehensive bioinformatics analyses to determine the expression profile of ANRGs and their prognostic implications in HCC. Next, a risk score model was established by least absolute shrinkage and selection operator (Lasso) Cox regression analysis. Then, the prognostic value of the risk score in HCC and its correlation with clinical characteristics of HCC patients were further explored. Additionally, machine learning was utilized to identify the outstanding ANRGs to the risk score. Finally, the protein expression of DAP3 was examined on a tissue microarray (TMA), and the potential mechanisms of DAP3 in HCC was explored. Results: ANRGs were dysregulated in HCC, with a low frequency of somatic mutations and associated with prognosis of HCC patients. Then, nine ANRGs were selected to construct a risk score signature based on the LASSO model. The signature presented a strong ability of risk stratification and prediction for overall survival in HCC patients.Additionally, high risk scores were closely correlated with unfavorable clinical features such as advanced pathological stage, poor histological differentiation and vascular invasion. Moreover, The XGBoost algorithm verified that DAP3 was an important risk score contributor. Further immunohistochemistry determined the elevated expression of DAP3 in HCC tissues compared with nontumor tissues. Finally, functional analyses showed that DAP3 may promote HCC progression through multiple cancer-related pathways and suppress immune infiltration. Conclusion: In conclusion, the anoikis-based signature can be utilized as a novel prognostic biomarker for HCC, and DAP3 may play an important role in the development and progression of HCC.

Integrated bioinformatical and in vitro study on drug targets for liver cirrhosis based on unsupervised consensus clustering and immune cell infiltration

Liver cirrhosis is one of the most common cause of death in the world. The progress of liver cirrhosis involves health, liver cirrhosis and liver cancer, leading to great challenges in the diagnosis of the disease. Drug targets, which could be obtained conveniently, can help clinicians improve prognosis and treatment. Liver cirrhosis is associated with serum calcium levels. And studies reported Tanshinone IIA plays a therapeutic role in liver injury through activating calcium-dependent apoptosis. In this study, we explored the diagnostic key targets of Tanshinone IIA in liver cirrhosis through exploration of comprehensive dataset including health, liver cirrhosis and liver cancer patients. The unsupervised consensus clustering algorithm identified 3 novel subtypes in which differentially expressed genes (DEGs) between both subtypes were found by pairwise comparison. Then, 4 key drug targets of Tanshinone IIA were determined through the intersection of these DEGs. The diagnostic performance of target genes was assessed and further verified in the external dataset. We found that the 4 key drug targets could be used as effective diagnostic biomarkers. Then the immune scores in the high and low expression groups of target genes were estimated to identify significantly expressed immune cells. In addition, the immune infiltration of high and low target gene expression groups in several immune cells were significantly different. The findings suggest that 4 key drug targets may be a simple and useful diagnostic tool for predicting patients with cirrhosis. We further studied the carcinogenesis role of AKR1C3 and TPX2 in vitro. Both mRNA and protein expression in hepatoma carcinoma cells was detected using qRT-PCR and Western blot. And the knockdown of AKR1C3 and TPX2 significantly suppressed cell proliferation, migration and invasion.

An anoikis-related gene signature predicts prognosis and reveals immune infiltration in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is a global health burden with poor prognosis. Anoikis, a novel programmed cell death, has a close interaction with metastasis and progression of cancer. In this study, we aimed to construct a novel bioinformatics model for evaluating the prognosis of HCC based on anoikis-related gene signatures as well as exploring the potential mechanisms.

Materials and methods

We downloaded the RNA expression profiles and clinical data of liver hepatocellular carcinoma from TCGA database, ICGC database and GEO database. DEG analysis was performed using TCGA and verified in the GEO database. The anoikis-related risk score was developed via univariate Cox regression, LASSO Cox regression and multivariate Cox regression, which was then used to categorize patients into high- and low-risk groups. Then GO and KEGG enrichment analyses were performed to investigate the function between the two groups. CIBERSORT was used for determining the fractions of 22 immune cell types, while the ssGSEA analyses was used to estimate the differential immune cell infiltrations and related pathways. The "pRRophetic" R package was applied to predict the sensitivity of administering chemotherapeutic and targeted drugs.

Results

A total of 49 anoikis-related DEGs in HCC were detected and 3 genes (EZH2, KIF18A and NQO1) were selected out to build a prognostic model. Furthermore, GO and KEGG functional enrichment analyses indicated that the difference in overall survival between risk groups was closely related to cell cycle pathway. Notably, further analyses found the frequency of tumor mutations, immune infiltration level and expression of immune checkpoints were significantly different between the two risk groups, and the results of the immunotherapy cohort showed that patients in the high-risk group have a better immune response. Additionally, the high-risk group was found to have higher sensitivity to 5-fluorouracil, doxorubicin and gemcitabine.

Conclusion

The novel signature of 3 anoikis-related genes (EZH2, KIF18A and NQO1) can predict the prognosis of patients with HCC, and provide a revealing insight into personalized treatments in HCC.

The NQO1/p53/SREBP1 axis promotes hepatocellular carcinoma progression and metastasis by regulating Snail stability

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide, and its abnormal metabolism affects the survival and prognosis of patients. Recent studies have found that NAD(P)H quinone oxidoreductase-1 (NQO1) played an important role in tumor metabolism and malignant progression. However, the molecular mechanisms by which NQO1 regulates lipid metabolism during HCC progression remain unclear. In this study, bioinformatics analysis and immunohistochemical results showed that NQO1 was highly expressed in HCC tissues and its high expression was closely related to the poor prognosis of HCC patients. Overexpression of NQO1 promoted the cell proliferation, epithelial-to-mesenchymal transition (EMT) process, and angiogenesis of HCC cells. Luciferase reporter assay further revealed that NQO1/p53 could induce the transcriptional activity of SREBP1, consequently regulating HCC progression through lipid anabolism. In addition, Snail protein was stabilized by NQO1/p53/SREBP1 axis and triggered the EMT process, and participated in the regulatory role of NQO1/p53/SREBP1 axis in HCC. Together, these data indicated that NQO1/SREBP1 axis promoted the progression and metastasis of HCC, and might be a potential therapeutic target for HCC.

Impact of JMJD6 on intrahepatic cholangiocarcinoma

The association of Jumonji domain-containing 6 (JMJD6) with the prognosis of various types of cancer has been demonstrated, except in intrahepatic cholangiocarcinoma (ICC). The present study aimed to clarify the impact of JMJD6 on ICC. The liver specimens of 51 patients who underwent surgery for ICC were analyzed for JMJD6 expression using immunohistochemistry staining. The relationship between clinicopathological factors and JMJD6 expression was investigated. The cellular activity was also evaluated in JMJD6 knocked down cells with Transwell migration assay and viability assay. In the immunohistochemistry staining of clinical samples, high expression of JMJD6 was seen in 32 of 51 samples. High expression was also associated with improved overall survival (OS) and recurrence-free survival (RFS) (P=0.0033 and 0.048, respectively). Further analyses revealed that higher JMJD6 expression was one of the improved independent prognostic factors of OS and RFS. Expression of JMJD6 was knocked down in commercial culture cell lines of ICC, and RNA and protein were extracted to analyze the downstream gene expression using RNA-sequencing and western blotting. JMJD6 knockdown was associated with higher programmed death-ligand 1 (PD-L1) expression in RNA-sequencing and western blotting. In addition, PD-L1 expression was higher in JMJD6 low expression clinical samples when measured using immunohistochemistry staining. In conclusion, high expression of JMJD6 was an independent favorable prognostic factor of ICC. JMJD6 may influence the prognosis of ICC through the regulation of PD-L1 expression.

Ferroptosis is induced by lenvatinib through fibroblast growth factor receptor-4 inhibition in hepatocellular carcinoma

The tyrosine kinase inhibitor lenvatinib is used to treat advanced hepatocellular carcinoma (HCC). Ferroptosis is a type of cell death characterized by the iron‐dependent accumulation of lethal lipid reactive oxygen species (ROS). Nuclear factor erythroid‐derived 2‐like 2 (Nrf2) protects HCC cells against ferroptosis. However, the mechanism of lenvatinib‐induced cytotoxicity and the relationships between lenvatinib resistance and Nrf2 are unclear. Thus, we investigated the relationship between lenvatinib and ferroptosis and clarified the involvement of Nrf2 in lenvatinib‐induced cytotoxicity. Cell viability, lipid ROS levels, and protein expression were measured using Hep3B and HuH7 cells treated with lenvatinib or erastin. We examined these variables after silencing fibroblast growth factor receptor‐4 (FGFR4) or Nrf2 and overexpressing‐Nrf2. We immunohistochemically evaluated FGFR4 expression in recurrent lesions after resection and clarified the relationship between FGFR4 expression and lenvatinib efficacy. Lenvatinib suppressed system X_c⁻ (xCT) and glutathione peroxidase 4 (GPX4) expression. Inhibition of the cystine import activity of xCT and GPX4 resulted in the accumulation of lipid ROS. Silencing‐FGFR4 suppressed xCT and GPX4 expression and increased lipid ROS levels. Nrf2‐silenced HCC cells displayed sensitivity to lenvatinib and high lipid ROS levels. In contrast, Nrf2‐overexpressing HCC cells displayed resistance to lenvatinib and low lipid ROS levels. The efficacy of lenvatinib was significantly lower in recurrent HCC lesions with low‐FGFR4 expression than in those with high‐FGFR4 expression. Patients with FGFR4‐positive HCC displayed significantly longer progression‐free survival than those with FGFR4‐negative HCC. Lenvatinib induced ferroptosis by inhibiting FGFR4. Nrf2 is involved in the sensitivity of HCC to lenvatinib.

Copy number profiling of circulating free DNA predicts transarterial chemoembolization response in advanced hepatocellular carcinoma

Transarterial chemoembolization (TACE) is the most commonly used treatment for advanced hepatocellular carcinoma (HCC), but still lacks accurate real-time biomarkers for monitoring its therapeutic efficacy. Here, we explored whether copy number profiling of circulating free DNA (cfDNA) could be utilized to predict responses and prognosis in HCC patients with TACE treatment. In total, 266 plasma cfDNA samples were collected from 64 HCC patients, 57 liver cirrhosis (LC) patients and 32 healthy volunteers. We performed low-depth whole-genome sequencing (LD-WGS) on cfDNA samples to conduct copy number variants (CNVs) analysis and tumor fraction (TFx) quantification. Then, the correlation between TFx/CNVs and therapeutic efficacy, treatment outcomes and lipiodol deposition were explored. The change of TFx during TACE treatment was associated with patient tumor burden and could accurately predict treatment response and prognosis, and at an earlier timepoint than modified RECIST (mRECIST) assessment, providing an alternative strategy: the chromosomal 16q/NQO1 amplification indicated worse therapeutic response; in patients who underwent multiple TACE sessions, TFx change during their first TACE treatment reflected the long-term survival; additionally, the copy number amplification of chromosome 1q, 3p, 6p, 8q, 10p, 12q, 18p or 18q affected lipiodol deposition. Overall, we have provided a new liquid biopsy approach for future TACE management of HCC patients.

Impact of Nuclear Factor Erythroid 2-Related Factor 2 in Hepatocellular Carcinoma: Cancer Metabolism and Immune Status

We examined phosphorylated nuclear factor erythroid 2–related factor 2 (P‐NRF2) expression in surgically resected primary hepatocellular carcinoma (HCC) and investigated the association of P‐NRF2 expression with clinicopathological features and patient outcome. We also evaluated the relationship among NRF2, cancer metabolism, and programmed death ligand 1 (PD‐L1) expression. In this retrospective study, immunohistochemical staining of P‐NRF2 was performed on the samples of 335 patients who underwent hepatic resection for HCC. Tomography/computed tomography using fluorine‐18 fluorodeoxyglucose was performed, and HCC cell lines after NRF2 knockdown were analyzed by array. We also analyzed the expression of PD‐L1 after hypoxia inducible factor 1α (HIF1A) knockdown in NRF2‐overexpressing HCC cell lines. Samples from 121 patients (36.1%) were positive for P‐NRF2. Positive P‐NRF2 expression was significantly associated with high alpha‐fetoprotein (AFP) expression, a high rate of poor differentiation, and microscopic intrahepatic metastasis. In addition, positive P‐NRF2 expression was an independent predictor for recurrence‐free survival and overall survival. NRF2 regulated glucose transporter 1, hexokinase 2, pyruvate kinase isoenzymes L/R, and phosphoglycerate kinase 1 expression and was related to the maximum standardized uptake value. PD‐L1 protein expression levels were increased through hypoxia‐inducible factor 1α after NRF2 overexpression in HCC cells. Conclusions: Our large cohort study revealed that P‐NRF2 expression in cancer cells was associated with clinical outcome in HCC. Additionally, we found that NRF2 was located upstream of cancer metabolism and tumor immunity.

Implications of reactive oxygen species on cancer formation and its treatment

Elevated levels of reactive oxygen species (ROS) are a hallmark of cancer. Although increased ROS concentrations play important roles in cancer formation and progression, levels above a cytotoxic threshold cause cancer cell death. Cancer cells adapt to high concentrations of ROS via antioxidant production and reprogrammed cellular metabolism (eg, the Warburg effect). Because some widely used anticancer therapies such as radiation therapy and chemotherapy rely on ROS accumulation as a mechanism to induce cancer cell death, a cancer cell's ability to control ROS levels is a driver of treatment resistance and a critical consideration for successful cancer treatment. The necessity for cancer cells to adapt to elevated levels of ROS to survive may represent an Achilles heel for some malignancies, as therapies designed to interfere with this adaptation would be expected to kill cancer cells. In this review, we provide an overview of the implications of ROS on cancer formation and anticancer treatment strategies, with a focus on treatment-resistant disease.

ARID1A Deficiency Is Associated With High Programmed Death Ligand 1 Expression in Hepatocellular Carcinoma

The clinicopathological features of carcinomas expressing AT-rich interaction domain 1a (ARID1A) and programmed death ligand 1 (PD-L1) in HCC are poorly understood. Here, we examined ARID1A and PD-L1 expression in surgically resected primary hepatocellular carcinoma (HCC) and the association of ARID1A and PD-L1 expression with clinicopathological features and patient outcomes. Their association with ARID1A expression and tumor-associated CD68-positive macrophage was further explored. Using a database of 255 patients who underwent hepatic resection for HCC, immunohistochemical staining of ARID1A, PD-L1, and CD68 was performed. We also analyzed the expression PD-L1 after ARID1A knockdown in HCC cell lines. Samples from 81 patients (31.7%) were negative for ARID1A. Negative ARID1A expression was significantly associated with male sex, high alpha-fetoprotein, high des-gamma-carboxyprothrombin, large tumor size, high rate of poor differentiation, microscopic intrahepatic metastasis, and PD-L1 expression. In addition, negative ARID1A expression was an independent predictor for recurrence-free survival, overall survival, and positive PD-L1 expression. Stratification based on ARID1A and PD-L1 expression in cancer cells was also significantly associated with unfavorable outcomes. PD-L1 protein expression levels were increased through phosphoinositide 3-kinase/AKT signaling after ARID1A knockdown in HCC cells. HCC with ARID1A-low expression was significantly correlated with high levels of tumor-associated CD68-positive macrophage. Conclusion: Our large cohort study showed that ARID1A expression in cancer cells was associated with a poor clinical outcome in patients with HCC, PD-L1 expression in cancer cells, and tumor microenvironment. Therefore, ARID1A may be a potential molecular biomarker for the selection of patients with HCC for anti-programmed death 1/PD-L1 antibody therapy.

CMTM6 Stabilizes PD-L1 Expression and Is a New Prognostic Impact Factor in Hepatocellular Carcinoma

CKLF-like MARVEL transmembrane domain containing 6 (CMTM6) was identified as a regulator of programmed death ligand 1 (PD-L1), which induces antitumor immunity in several cancers. This study aimed to clarify the relationship between CMTM6 and PD-L1 expression and clinical outcomes in patients with hepatocellular carcinoma (HCC). In total, 259 patients with HCC who had undergone hepatic resection were enrolled. Immunohistochemical staining for CMTM6 and PD-L1 was performed. The relationships between CMTM6 expression and the clinicopathological characteristics and outcomes were analyzed. Additionally, the stabilization of PD-L1 expression and regulation of malignant activities by CMTM6 were examined in vitro. Our patients were divided into high (n = 65, 25.1%) and low (n = 194, 74.9%) CMTM6 expression groups. High CMTM6 expression was significantly associated with malignant aggregates, including poor differentiation (P < 0.0001), microscopic intrahepatic metastasis (P = 0.0369), and multiple intrahepatic recurrences (P = 0.0211). CMTM6 expression was significantly correlated with PD-L1 expression in HCC tissues (P < 0.0001). The patients were classified into three groups: high CMTM6/PD-L1 positive (n = 21), high CMTM6/ PD-L1 negative (n = 44), and low CMTM6 (n = 194) expression pattern groups. Overall survival was significantly different among the three groups (P < 0.0001). Additionally, immunohistochemical double staining revealed that CMTM6 and PD-L1 were co-expressed on HCC cells. In vitro, PD-L1 expression was enhanced at late time points in the presence of CMTM6 expression. CMTM6 also regulated epithelial-to-mesenchymal transition and stemness phenotypes in HCC cells. Conclusion: Our large cohort study found that CMTM6 co-expressed with PD-L1 was strongly associated with the clinical outcome in patients with HCC. The evaluation of CMTM6 combined with PD-L1 in HCC might be useful for patient selection in immune checkpoint therapy.

The NRF2, Thioredoxin, and Glutathione System in Tumorigenesis and Anticancer Therapies

Cancer remains an elusive, highly complex disease and a global burden. Constant change by acquired mutations and metabolic reprogramming contribute to the high inter- and intratumor heterogeneity of malignant cells, their selective growth advantage, and their resistance to anticancer therapies. In the modern era of integrative biomedicine, realizing that a personalized approach could benefit therapy treatments and patients' prognosis, we should focus on cancer-driving advantageous modifications. Namely, reactive oxygen species (ROS), known to act as regulators of cellular metabolism and growth, exhibit both negative and positive activities, as do antioxidants with potential anticancer effects. Such complexity of oxidative homeostasis is sometimes overseen in the case of studies evaluating the effects of potential anticancer antioxidants. While cancer cells often produce more ROS due to their increased growth-favoring demands, numerous conventional anticancer therapies exploit this feature to ensure selective cancer cell death triggered by excessive ROS levels, also causing serious side effects. The activation of the cellular NRF2 (nuclear factor erythroid 2 like 2) pathway and induction of cytoprotective genes accompanies an increase in ROS levels. A plethora of specific targets, including those involved in thioredoxin (TRX) and glutathione (GSH) systems, are activated by NRF2. In this paper, we briefly review preclinical research findings on the interrelated roles of the NRF2 pathway and TRX and GSH systems, with focus given to clinical findings and their relevance in carcinogenesis and anticancer treatments.

Nrf2 in Neoplastic and Non-Neoplastic Liver Diseases

Simple Summary

Although the Keap1-Nrf2 pathway represents a powerful cell defense mechanism against a variety of toxic insults, its role in acute or chronic liver damage and tumor development is not completely understood. This review addresses how Nrf2 is involved in liver pathophysiology and critically discusses the contrasting results emerging from the literature. The aim of the present report is to stimulate further investigation on the role of Nrf2 that could lead to define the best strategies to therapeutically target this pathway.

Abstract

Activation of the Keap1/Nrf2 pathway, the most important cell defense signal, triggered to neutralize the harmful effects of electrophilic and oxidative stress, plays a crucial role in cell survival. Therefore, its ability to attenuate acute and chronic liver damage, where oxidative stress represents the key player, is not surprising. On the other hand, while Nrf2 promotes proliferation in cancer cells, its role in non-neoplastic hepatocytes is a matter of debate. Another topic of uncertainty concerns the nature of the mechanisms of Nrf2 activation in hepatocarcinogenesis. Indeed, it remains unclear what is the main mechanism behind the sustained activation of the Keap1/Nrf2 pathway in hepatocarcinogenesis. This raises doubts about the best strategies to therapeutically target this pathway. In this review, we will analyze and discuss our present knowledge concerning the role of Nrf2 in hepatic physiology and pathology, including hepatocellular carcinoma. In particular, we will critically examine and discuss some findings originating from animal models that raise questions that still need to be adequately answered.

P-cadherin induces anoikis-resistance of matrix-detached breast cancer cells by promoting pentose phosphate pathway and decreasing oxidative stress

Successful metastatic spreading relies on cancer cells with stem-like properties, glycolytic metabolism and increased antioxidant protection, allowing them to escape anoikis and to survive in circulation. The expression of P-cadherin, a poor prognostic factor in breast cancer, is associated with hypoxic, glycolytic and acidosis biomarkers. In agreement, P-cadherin-enriched breast cancer cell populations presents a glycolytic and an acid-resistance phenotype. Our aim was to evaluate whether P-cadherin expression controls the glycolytic and oxidative phosphorylation fluxes of matrix-detached breast cancer cells, acting as an antioxidant and enhancing their survival in anchorage-independent conditions. By using matrix-detached breast cancer cells, we concluded that P-cadherin increases glucose-6-phosphate dehydrogenase expression, up-regulating the carbon flux through the pentose phosphate pathway, while inhibiting pyruvate oxidation to acetyl-coA via pyruvate dehydrogenase kinase-4 (PDK-4) activation. Accordingly, P-cadherin expression conferred increased sensitivity to dichloroacetate (DCA), a PDK inhibitor. P-cadherin expression also regulates oxidative stress in matrix-detached breast cancer cells, through the control of antioxidant systems, such as catalase and superoxide dismutases (SOD)1 and 2, providing these cells with an increased resistance to doxorubicin-induced anoikis. Importantly, this association was validated in primary invasive breast carcinomas, where an enrichment of SOD2 was found in P-cadherin-overexpressing breast carcinomas. In conclusion, we propose that P-cadherin up-regulates carbon flux through the pentose phosphate pathway and decreases oxidative stress in matrix-detached breast cancer cells. These metabolic remodeling and antioxidant roles of P-cadherin can promote the survival of breast cancer cells in circulation and in metastatic sites, being a possible player in breast cancer therapeutic resistance to pro-oxidant-based interventions.

Modulation of Nqo1 activity intercepts anoikis resistance and reduces metastatic potential of hepatocellular carcinoma

The processing of intracellular reactive oxygen species (ROS) by nuclear factor erythroid‐derived 2‐like 2 (Nrf2) and NADPH quinone oxidoreductase 1 (Nqo1) is important for tumor metastasis. However, the clinical and biological significance of Nrf2/Nqo1 expression in hepatocellular carcinoma (HCC) remains unclear. We aimed to clarify the clinical importance of Nrf2/Nqo1 expression in HCC and evaluate the association of Nrf2/Nqo1 expression with HCC metastasis. We also evaluated the impact of Nqo1 modulation on HCC metastatic potential. We used spheroids derived from HCC cell lines. In anchorage‐independent culture, HCC cells showed increased ROS, leading to the upregulation of Nrf2/Nqo1. Futile stimulation of Nqo1 by β‐lapachone induces excessive oxidative stress and dramatically increased anoikis sensitivity, finally diminishing the spheroid formation ability, which was far stronger than depletion of Nqo1. We analyzed 117 cases of primary HCC who underwent curative resection. Overexpression of Nrf2/Nqo1 in primary HCC was associated with tumor size, high α‐fetoprotein, and des‐γ‐carboxy‐prothrombin levels. Overexpression of Nrf2/Nqo1 was also associated with multiple intrahepatic recurrences (P = .0073) and was an independent risk factor for poor prognosis (P = .0031). NADPH quinone oxidoreductase 1 plays an important role in anchorage‐independent survival, which is essential for survival for circulation and distant metastasis of HCC cells. These results suggest that targeting Nqo1 activity could be a potential strategy for HCC adjuvant therapy.