URI alleviates tyrosine kinase inhibitors-induced ferroptosis by reprogramming lipid metabolism in p53 wild-type liver cancers.

The clinical benefit of tyrosine kinase inhibitors (TKIs)-based systemic therapy for advanced hepatocellular carcinoma (HCC) is limited due to drug resistance. Here, we uncover that lipid metabolism reprogramming mediated by unconventional prefoldin RPB5 interactor (URI) endows HCC with resistance to TKIs-induced ferroptosis. Mechanistically, URI directly interacts with TRIM28 and promotes p53 ubiquitination and degradation in a TRIM28-MDM2 dependent manner. Importantly, p53 binds to the promoter of stearoyl-CoA desaturase 1 (SCD1) and represses its transcription. High expression of URI is correlated with high level of SCD1 and their synergetic expression predicts poor prognosis and TKIs resistance in HCC. The combination of SCD1 inhibitor aramchol and deuterated sorafenib derivative donafenib displays promising anti-tumor effects in p53-wild type HCC patient-derived organoids and xenografted tumors. This combination therapy has potential clinical benefits for the patients with advanced HCC who have wild-type p53 and high levels of URI/SCD1.

PTEN deficiency facilitates gemcitabine efficacy in cancer by modulating the phosphorylation of PP2Ac and DCK.

Gemcitabine is a nucleoside analog that has been successfully used in the treatment of multiple cancers. However, intrinsic or acquired resistance reduces the chemotherapeutic potential of gemcitabine. Here, we revealed a previously unappreciated mechanism by which phosphatase and tensin homolog (PTEN), one of the most frequently mutated genes in human cancers, dominates the decision-making process that is central to the regulation of gemcitabine efficacy in cholangiocarcinoma (CCA). By investigating a gemcitabine-treated CCA cohort, we found that PTEN deficiency was correlated with the improved efficacy of gemcitabine-based chemotherapy. Using cell-based drug sensitivity assays, cell line-derived xenograft, and patient-derived xenograft models, we further confirmed that PTEN deficiency or genetic-engineering down-regulation of PTEN facilitated gemcitabine efficacy both in vitro and in vivo. Mechanistically, PTEN directly binds to and dephosphorylates the C terminus of the catalytic subunit of protein phosphatase 2A (PP2Ac) to increase its enzymatic activity, which further dephosphorylates deoxycytidine kinase (DCK) at Ser74 to diminish gemcitabine efficacy. Therefore, PTEN deficiency and high phosphorylation of DCK predict a better response to gemcitabine-based chemotherapy in CCA. We speculate that the combination of PP2A inhibitor and gemcitabine in PTEN-positive tumors could avoid the resistance of gemcitabine, which would benefit a large population of patients with cancer receiving gemcitabine or other nucleoside analogs.

PTEN Deficiency Facilitates Exosome Secretion and Metastasis in Cholangiocarcinoma by Impairing TFEB-mediated Lysosome Biogenesis.

BACKGROUND & AIMS: In eukaryotes, the ubiquitin-proteasome system and the autophagy-lysosome pathway are essential for maintaining cellular proteostasis and associated with cancer progression. Our previous studies have demonstrated that phosphatase and tensin homolog (PTEN), one of the most frequently mutated genes in human cancers, limits proteasome abundance and determines chemosensitivity to proteasome inhibitors in cholangiocarcinoma (CCA). However, whether PTEN regulates the lysosome pathway remains unclear. METHODS: We tested the effects of PTEN on lysosome biogenesis and exosome secretion using loss- and gain-of-function strategies in CCA cell lines. Using in vitro dephosphorylation assays, we explored the regulatory mechanism between PTEN and the key regulator of lysosome biogenesis, transcription factor EB (TFEB). Using the migration assays, invasion assays, and trans-splenic liver metastasis mouse models, we evaluated the function of PTEN deficiency, TFEB-mediated lysosome biogenesis, and exosome secretion on tumor metastasis. Moreover, we investigated the clinical significance of PTEN expression and exosome secretion by retrospective analysis. RESULTS: PTEN facilitated lysosome biogenesis and acidification through its protein phosphatase activity to dephosphorylate TFEB at Ser211. Notably, PTEN deficiency increased exosome secretion by reducing lysosome-mediated degradation of multi-vesicular bodies, which further facilitated the proliferation and invasion of CCA. TFEB agonist curcumin analog C1 restrained the metastatic phenotype caused by PTEN deficiency in mouse models, and we highlighted the correlation between PTEN deficiency and exosome secretion in clinical cohorts. CONCLUSIONS: In CCA, PTEN deficiency impairs lysosome biogenesis to facilitate exosome secretion and cancer metastasis in a TFEB phosphorylation-dependent manner.

Gankyrin and TIGAR cooperatively accelerate glucose metabolism toward the PPP and TCA cycle in hepatocellular carcinoma.

Oncogene-derived metabolic reprogramming is important for anabolic growth of cancer cells, which is now considered to be not simply rely on glycolysis. Pentose phosphate pathway and tricarboxylic acid cycle also play pivotal roles in helping cancer cells to meet their anabolic and energy demands. The present work focused on gankyrin, a relatively specific oncogene in hepatocellular carcinoma (HCC), and its impact on glycolysis and mitochondrial homeostasis. Metabolomics, RNA-seq analysis, and subsequent conjoint analysis illustrated that gankyrin regulated the pentose phosphate pathway (PPP), tricarboxylic acid (TCA) cycle, and mitochondrial function and homeostasis, which play pivotal roles in tumor development. Mechanistically, gankyrin was found to modulate HCC metabolic reprogramming via TIGAR. Gankyrin positively regulated the transcription of TIGAR through Nrf2, which bound to the antioxidant response elements (AREs) in the promoter of TIGAR. Interestingly, TIGAR feedback regulated the transcription of Nrf2 and subsequently gankyrin by promoting nuclear importation of PGC1α. The loop between gankyrin, Nrf2, and TIGAR accelerated glucose metabolism toward the PPP and TCA cycle, which provided vital building blocks, such as NADPH, ATP, and ribose of tumor and further facilitated the progression of HCC.

[Mechanism of puerarin reversing SH-SY5Y cell injury induced by Aß_(1-42) based on proteomics].

Puerarin has the anti-Alzheimer's disease (AD) activity,which can reverse nerve injury induced by Aßand inhibit neuronal apoptosis.However,its potential pharmacodynamic mechanism still needs to be further researched.The occurrence and development of AD is due to the change of multiple metabolic links in the body,which leads to the destruction of balance.Puerarin may act on multiple targets and multiple metabolic processes to achieve therapeutic purposes.Quantitative proteomic analysis provides a new choice to understand the mechanism as completely as possible.This research adopted SH-SY5Y cells induced by Aß_(1-42)to establish AD cell model,and Aßimmunofluorescence detection showed that Aßdecreased significantly after puerarin intervention.The mechanism of puerarin reversing SH-SY5Y cell injured by Aß_(1-42)was further explored by using label-free non-labeled quantitative technology and Western blot detection based on bioinformatics analysis result.The results showed that most of the differential proteins were related to biological processes such as cellular component organization or biogenesis,cellular component organization and cellular component biogenesis,and they mainly participated in the top ten pathways of P value such as pathogenic Escherichia coli infection,m TOR signaling pathway,regulation of autophagy,regulation of actin cytoskeleton,spliceosome,hepatocellular carcinoma,tight junction,non-small cell lung cancer,apoptosis and gap junction.Annexin V/PI flow cytometry and TUNEL were used to detect apoptosis,and the results showed that Aßdecreased significantly and the rate of apoptosis decreased significantly after puerarin intervention.Western blot analysis found that the protein expression level of autophagy related protein LC3Ⅱwas up-regulated after Aßinduction,and the degree of this up-regulation was further enhanced in puerarin intervention group.The trend of the ratio of LC3Ⅱ/LC3Ⅰamong groups was the same as the protein expression level of LC3Ⅱ，the protein expression level of p62 in the control group,AD model group and puerarin intervention group decreased successively.Protein interaction network analysis showed that CAP1 was correlated with TUBA1B,HSP90AB2P,DNM1L,TUBA1A and ERK1/2,and the correlation between CAP1 and ERK1/2 was the highest among them.Western blot showed that the expressions of p-ERK1/2,Bax and CAP1 were significantly down-regulated and the protein expression level of Bcl-2 was significantly up-regulated after puerarin intervention.Therefore,puerarin might improve the SH-SY5Y cells injured by Aß_(1-42)through the interaction of multiple biological processes and pathways in cells multiple locations,and CAP1 might play an important role among them.

PTEN deficiency facilitates the therapeutic vulnerability to proteasome inhibitor bortezomib in gallbladder cancer.

Gallbladder cancer (GBC) is an aggressive malignancy of biliary tract with poor prognosis. Although several studies have shown the frequency of relevant genetic alterations, there are few genetic models or translational studies that really benefit for GBC treatment in the era of precision medicine. By targeted sequencing and immunohistochemistry staining, we identified that phosphate and tension homology deleted on chromosome ten (PTEN) was frequently altered in GBC specimens, and loss of PTEN expression was independently correlated with poor survival outcomes. Further drug screening assays revealed proteasome inhibitor bortezomib as a promising agent for GBC treatment, and knockdown of PTEN increased bortezomib efficacy both in vivo and in vitro. Therapeutic evaluation of patient derived xenografts (PDXs) strongly supported the utilization of bortezomib in PTEN deficient GBC. Mechanically, functional PTEN inhibited ARE-dependent transcriptional activity, the same machinery regulating the transcription of proteasome subunits, thus PTEN suppressed proteasome activity and bortezomib sensitivity. Through siRNA screening, we identified the ARE-related transcriptional suppressor BACH1 involved in PTEN-mediated proteasome inhibition and regulated by PTEN-AKT1 axis. In summary, our study indicates that proteasome activity represents a prime therapeutic target in PTEN-deficient GBC tumors, which is worthy of further clinical validation.

RPB5-Mediating Protein Promotes Cholangiocarcinoma Tumorigenesis and Drug Resistance by Competing With NRF2 for KEAP1 Binding.

BACKGROUND AND AIMS: Cancer cell survival depends on the balance between reactive oxygen species production and scavenging, which is regulated primarily by NRF2 during tumorigenesis. Here, we demonstrate that deletion of RBP5-mediating protein (RMP) in an autonomous mouse model of intrahepatic cholangiocarcinoma (ICC) delays tumor progression. APPROACH AND RESULTS: RMP-overexpressing tumor cells exhibited enhanced tolerance to oxidative stress and apoptosis. Mechanistically, RMP competes with NRF2 for binding to the Kelch domain of KEAP1 (Kelch-like ECH-associated protein 1) through the E**E motif, leading to decreased NRF2 degradation via ubiquitination, thus increasing NRF2 nuclear translocation and downstream transactivation of antioxidant genes. This RMP-KEAP1-NRF2 axis promotes ICC tumorigenesis, metastasis, and drug resistance. Consistent with these findings, the RMP level in human ICC is positively correlated with the protein level of NRF2 and is associated with poor prognosis. CONCLUSION: These findings reveal that RMP is involved in the oxidative stress defense program and could be exploited for targeted cancer therapies.

Two P5CS genes from common bean exhibiting different tolerance to salt stress in transgenic Arabidopsis.

Many plants accumulate proline in response to salt stress. Δ-pyrroline-5-carboxylate synthetase (P5CS) is the rate-limiting enzyme in proline biosynthesis in plants. Plasmid DNA (pCHF3-PvP5CS1 and pCHF3-PvP5CS2) containing the selectable neomycin phosphotransferase gene for kanamycin resistance and Phaseolus vulgaris P5CS (PvP5CS1 and PvP5CS2) cDNA was introduced into Arabidopsis plants using Agrobacterium-mediated gene transfer. Southern blot, northern blot and RT-PCR analyses demonstrated that the foreign genes were integrated into Arabidopsis chromosomal DNA and expressed. Single-gene transformants were analysed in this study. Transgenic plants expressed higher levels of PvP5CS1 and PvP5CS2 transcripts under salt stress conditions than under normal conditions. When treated with 0, 100 and 200 mM NaCl, the average proline content in leaves of transgenic plants was significantly higher (P < 0.01) than control plants. The average relative electrical conductivity (REC) of transgenic lines was significantly lower (P < 0.01) than control plants under salt stress condition. Biomass production of transgenic lines was significantly higher (P < 0.05) than control plants under 200 mM NaCl stress treatment. These results indicated that introducing PvP5CS1 and PvP5CS2 cDNA into transgenic Arabidopsis caused proline overproduction, increasing salt tolerance. Although the expression of PvP5CS1 in L4 lines and PvP5CS2 in S4 lines was the same under salt stress condition, the S4 lines accumulated 1.6 and 1.9 times more proline than the L4 lines under 100 and 200 mM NaCl treatments, respectively. The REC of S4 plants was 0.5 (100 mM NaCl) and 0.6 times (200 mM NaCl) that of L4 plants. The biomass production of S4 plants was 1.6 times (200 mM NaCl) more than in L4 plants. Total P5CS enzyme activity of S4 was significantly higher than that of L4. These results implied that the PvP5CS2 protein had stronger capacity to catalyze proline synthesis than PvP5CS1 under salt stress condition.

The effects of soy isoflavone on insulin sensitivity and adipocytokines in insulin resistant rats administered with high-fat diet.

The effects of soy isoflavone (SIF) on insulin sensitivity and adipocytokines in high-fat-diet-induced insulin resistant (IR) rats were studied. Male Sprague Dawley rats (n = 80) were randomly assigned into a basal diet fed group and high-fat diet fed group. The high-fat-diet-induced IR rats were assigned into IR model control group and three SIF-treated groups with different dosages. Thirty days later, the fasting blood glucose, insulin and adipocytokines in serum and mRNA expressions of adipocytokines in perirenal white adipose tissue were measured. The Homeostasis Model Assessment of IR was calculated. The administration of 450 mg kg(-1) d(-1) SIF decreased the body weights and depositions of visceral adipose tissue as well as improved insulin resistance in high-fat-diet-induced IR rats. The mechanisms were associated with SIF regulating the expression of adipocytokines, including adiponectin, leptin, resistin and TNF-alpha. SIF supplements may have favourable effects on insulin resistance in high-fat-diet-induced IR rats.

[Effects of soy isoflavone on levels of low-grade inflammatory peptides in rats with insulin resistance].

OBJECTIVE: To explore the effects of soy isoflavone (SIF) on low-grade inflammation in rats with high-fat diet-induced insulin resistance (IR) and explore the mechanisms of SIF in improving insulin sensitivity. METHODS: The rats with high-fat diet-induced IR were randomly divided into one model control group and 3 SIF groups gavaged with SIF water solutions at the doses of 50, 150, and 450 mg/kg, respectively. One month after the treatment, fasting blood glucose (FBG), fasting insulin (FINS), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), C-reactive protein (CRP), resistin and adiponectin in the serum were detected by enzymatic method, radioimmunoassay, or enzyme-linked immunosorbent assay. RESULTS: In the 150 and 450 mg/kg SIF groups, fasting body-weights, visceral adipose tissue deposition, FINS, resistin, TNF-alpha in serum, and IR index were lowered in comparison with the model control group, and in 450 mg/kg SIF group, serum IL-6 level was obviously lowered, and adiponectin increased. No differences were found in serum C-reactive protein levels between the 3 SIF groups. CONCLUSION: Soy isoflavone may ameliorate insulin sensitivity by decreasing visceral adipose deposition and adjusting low-grade inflammatory molecules derived from white adipose tissue.

[Effects of soy isoflavone on gene expression of resistin in insulin-resistance rats].

OBJECTIVE: To assess the effects of soy isoflavone (SIF) on improving insulin reistance (IR) status in IR rats induced by high-fat and high-sugar diet and explore the possible mechanisms. METHODS: IR rats were randomly divided into four groups according to their insulin resistance indices (IRI). The rats in one model control group and three SIF groups were fed via gavage with water solutions containing SIF at doses of 0 mg/ kg x bw, 50 mg/kg x bw, 150 mg/kg x bw, and 450 mg/kg x bw, respectively. After one month, fasting glucose, fasting insulin, resistin in serum, and resistin mRNA in adipocyte around kidney were detected by enzymologic method, radioimmunoassay, enzyme linked immunosorbent assay, and real time RT-PCR, respectively. RESULTS: Comparison between the model control group and the other groups revealed that serum resistin and resistin mRNA expression levels were lower in the 450 mg/kg x bw group, that insulin and IRI levels were lower in the 150 mg/ kg x bw group and 450 mg/kg x bw group, and that no differences in plasma glucose levels existed among the 4 groups. A positive correlation between IRI and serum resistin level (r = 0.355, P < 0.05) was observed. CONCLUSION: These results suggest that soy isoflavone may down-regulate resistin mRNA expression, decrease serum resistin level and enhance insulin sensitivity.

[Effects of soy isoflavone on low-grade inflammation in obese rats].

OBJECTIVE: To explore the effects of soy isoflavone (SIF) on low-grade inflammation in obese rats induced by high-fat diet, and to elucidate mechanisms of SIF in improving insulin sensitivity. METHODS: Obese rats were randomly divided into 4 groups: One model control group and 3 SIF groups that were given water solutions with SIF at 0 mg/(kg x d), 50 mg/(kg x d), 150 mg/(kg x d), and 450 mg/(kg x d), respectively. After one month, fasting glucose, fasting insulin, interleukin-6, tumor necrosis factor-alpha, C-reactive protein, resistin, and adiponectin in serum were detected by enzymic method, radioimmunoassay, and enzyme linked immunosorbent assay, respectively. RESULTS: In the 150 mg/(kg x d) group and 450 mg/(kg x d) group, fasting body-weights, viscera fatty deposition, and contents of insulin, interleukin-6, and tumor necrosis factor-alpha in serum were significantly lower; serum adiponectin levels were significantly higher; and serum resistin levels were significantly lower in the 450 mg/(kg d) group than those of the model control group. There was no difference in serum C-reactive protein levels among the 3 SIF groups. CONCLUSION: Soy isoflavone may improve the insulin sensitivity by decreasing viscera fatty deposition and adjusting low-grade inflammatory molecules derived from white adipose tissues.

[Effect of soy isoflavone on gene expression of leptin and insulin sensibility in insulin-resistant rats].

OBJECTIVE: To explore the effects of soy isoflavone (SIF) on gene expression of leptin and insulin sensibility in insulin-resistant (IR) rats induced by high-fat, and to reveal the mechanisms of SIF in ameliorating insulin sensibility. METHODS: IR rats were randomly divided into four groups based on their insulin-resistant indexes (IRI): one model control group and three SIF groups that were gavaged with water solutions with SIF at doses of 0 mg/kg, 50 mg/kg, 150 mg/kg, and 450 mg/kg, respectively. After one month, fasting glucose, fasting insulin, leptin in serum, and leptin mRNA in the perirenal adipocyte were detected by enzymic method, radioimmunoassay, enzyme linked immunosorbent assay, and real time quantitative RT-PCR, respectively. RESULTS: The model control group was used to compare against the other groups: (1) Insulin and IRI were lower in the 150 mg/kg and 450 mg/kg groups; (2) In the 450 mg/kg group, body weight and leptin mRNA expression were lower, serum leptin content was higher. CONCLUSION: These results indicate that soy isoflavone might decrease body weight of rats and leptin mRNA, increase serum leptin level, and ameliorate leptin and insulin sensitivities.

[Effects of soy isoflavone on gene expression of adiponectin in insulin-resistance rats induced by high-fat and high-sugar diet].

OBJECTIVE: To study the effects and mechanisms of soy isoflavone (SIF) on improving insulin resistance (IR) status in IR rats induced by high-fat and high-sugar diet. METHODS: IR rats induced by high-fat and high-sugar diet were assigned into four groups and gavaged with SIF at doses of 0 (model control group), 50, 150 and 450 mg/kg bw for 4 weeks, respectively. Insulin, glucose, adiponectin in serum and adiponectin mRNA in perirened adipocyte were detected. RESULTS: Compared with model control group, body weight and fat pad weight were lower, and serum adiponectin and adiponectin mRNA expression were higher in the 450 mg/kg bw group, insulin and insulin-resistance index were lower in the 150 mg/kg bw group and 450 mg/kg bw. There is no differences in plasma glucose levels among groups. There is an negative correlation between insulin-resistance index and serum adiponectin level (Y = 24.802 - 2.856X, r = - 0.881, n = 47, P < 0.01). CONCLUSION: These results suggest that soy isoflavone may decrease adipose deposition, increase serum adiponectin level, and ameliorate insulin sensitivity.