Deciphering the tumour immune microenvironment of hepatocellular carcinoma.

Current treatments for hepatocellular carcinoma (HCC) are less effective and prone to recurrence after surgery, so it's needed to seek new ideas for its therapy. Tumour immune microenvironment (TME) is crucial for the pathogenesis, development and metastasis of HCC. Interactions between immune cells and tumour cells significantly impact responses to immunotherapies and patient prognosis. In recent years, immunotherapies for HCC have shown promising potential, but the response rate is still unsatisfactory. Understanding their cross-talks is helpful for selecting potential therapeutic targets, predicting immunotherapy responses, determining immunotherapy efficacy, identifying prognostic markers and selecting individualized treatment options. In this paper, we reviewed the research advances on the roles of immune cells and multi-omic research associated with HCC pathogenesis and therapy, and future perspectives on TME.

The Molecular Biology of Prostate Cancer Stem Cells: From the Past to the Future.

Prostate cancer (PCa) continues to rank as the second leading cause of cancer-related mortality in western countries, despite the golden treatment using androgen deprivation therapy (ADT) or anti-androgen therapy. With decades of research, scientists have gradually realized that the existence of prostate cancer stem cells (PCSCs) successfully explains tumor recurrence, metastasis and therapeutic failure of PCa. Theoretically, eradication of this small population may improve the efficacy of current therapeutic approaches and prolong PCa survival. However, several characteristics of PCSCs make their diminishment extremely challenging: inherent resistance to anti-androgen and chemotherapy treatment, over-activation of the survival pathway, adaptation to tumor micro-environments, escape from immune attack and being easier to metastasize. For this end, a better understanding of PCSC biology at the molecular level will definitely inspire us to develop PCSC targeted approaches. In this review, we comprehensively summarize signaling pathways responsible for homeostatic regulation of PCSCs and discuss how to eliminate these fractional cells in clinical practice. Overall, this study deeply pinpoints PCSC biology at the molecular level and provides us some research perspectives.

[Cholesterol Metabolism and Tumor Immunity].

Cholesterol, an important lipid molecule of organisms, is involved in the formation of cell membrane structure, bile acid metabolism and steroid hormone synthesis, playing an important role in the regulation of cell structure and functions. In recent years, a large number of studies have shown that cholesterol metabolism is reprogrammed during tumor formation and development. In addition to directly affecting the biological behavior of tumor cells, cholesterol metabolic reprogramming also regulates the antitumor activity of immune cells in the tumor microenvironment. We reviewed herein the cholesterol metabolism reprogramming of and interactions among immune cells including myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), dendritic cells (DCs), and T cells in the tumor microenvironment. However, the relationship between cholesterol metabolism and tumor immunity in tumor microenvironment is complex and diversified. The differences and similarities of cholesterol metabolism reprogramming in tumor microenvironment in regulating immune cell activity and the specific regulatory mechanism are still unresolved issues. Targeted intervention of the cholesterol metabolism pathway of immune cells is expected to become a new strategy of cholesterol metabolism in tumor immunotherapy.

Compound C induces protective autophagy in human cholangiocarcinoma cells via Akt/mTOR-independent pathway.

Compound C, a well-known inhibitor of AMP-activated protein kinase (AMPK), has been reported to exert antitumor activities in some types of cells. Whether compound C can exert antitumor effects in human cholangiocarcinoma (CCA) remains unknown. Here, we demonstrated that compound C is a potent inducer of cell death and autophagy in human CCA cells. Autophagy inhibitors increased the cytotoxicity of compound C towards human CCA cells, as confirmed by increased LDH release, and PARP cleavage. It is notable that compound C treatment increased phosphorylated Akt, sustained high levels of phosphorylated p70S6K, and decreased mTOR regulated p-ULK1 (ser757). Based on the data that blocking PI3K/Akt or mTOR had no apparent influence on autophagic response, we suggest that compound C induces autophagy independent of Akt/mTOR signaling in human CCA cells. Further study demonstrated that compound C inhibited the phosphorylation of JNK and its target c-Jun. Blocking JNK by SP600125 or siRNA suppressed autophagy induction upon compound C treatment. Moreover, compound C induced p38 MAPK activation, and its inhibition promoted autophagy induction via JNK activation. In addition, compound C induced p53 expression, and its inhibition attenuated compound C-induced autophagic response. Thus, compound C triggers autophagy, at least in part, via the JNK and p53 pathways in human CCA cells. In conclusion, suppresses autophagy could increase compound C sensitivity in human CCA.

Cisplatin Disrupts Proteasome Bounce-Back Effect through Suppressing ZEB1/Nfe2l1 in Cholangiocarcinoma.

BACKGROUND: Bortezomib (BTZ) is a powerful proteasome inhibitor that has been approved for the treatment of haematologic malignancies. Its effectiveness has been assessed against different types of solid tumours. BTZ is ineffective in most solid tumours because of drug resistance, including cholangiocarcinoma, which is associated with a proteasome bounce-back effect. However, the mechanism through which proteasome inhibitors induce the proteasome bounce-back effect remains largely unknown. METHODS: Cholangiocarcinoma cells were treated with BTZ, cisplatin, or a combination of both. The mRNA levels of Nfe2l1 and proteasome subunit genes (PSMA1, PSMB7, PSMD1, PSMD11, PSMD14, and PSME4) were determined using quantitative real time polymerase chain reaction (qPCR). The protein levels of nuclear factor-erythroid 2-related factor 1 (Nfe2l1) and proteasome enzyme activity were evaluated using western blotting and proteasome activity assays, respectively. Transcriptome sequencing was performed to screen for potential transcription factors that regulate Nfe2l1 expression. The effect of zinc finger E-box-binding homeobox 1 (ZEB1) on the expression of Nfe2l1 and proteasome subunit genes, as well as proteasome enzyme activity, was evaluated after the knockdown of ZEB1 expression with siRNA before treatment with BTZ. The transcriptional activity of ZEB1 on the Nfe2l1 promoter was detected using dual-luciferase reporter gene and chromatin immunoprecipitation assays. Cell viability was measured using the cell counting kit-8 (CCK-8) assay and cell apoptosis was assessed using western blotting and flow cytometry. RESULTS: Cisplatin treatment of BTZ-treated human cholangiocarcinoma cell line (RBE) suppressed proteasome subunit gene expression (proteasome bounce-back) and proteasomal enzyme activity. This effect was achieved by reducing the levels of Nfe2l1 mRNA and protein. Our study utilised transcriptome sequencing to identify ZEB1 as an upstream transcription factor of Nfe2l1, which was confirmed using dual-luciferase reporter gene and chromatin immunoprecipitation assays. Notably, ZEB1 knockdown using siRNA (si-ZEB1) hindered the expression of proteasome subunit genes under both basal and BTZ-induced conditions, leading to the inhibition of proteasomal enzyme activity. Furthermore, the combination treatment with BTZ, cisplatin, and si-ZEB1 significantly reduced the viability of RBE cells. CONCLUSIONS: Our study uncovered a novel mechanism through which cisplatin disrupts the BTZ-induced proteasome bounce-back effect by suppressing the ZEB1/Nfe2l1 axis in cholangiocarcinoma. This finding provides a theoretical basis for developing proteasome inhibitor-based strategies for the clinical treatment of cholangiocarcinoma and other tumours.

Disturbance of Ca2+ homeostasis converts pro-Met into non-canonical tyrosine kinase p190MetNC in response to endoplasmic reticulum stress in MHCC97 cells.

c-Met, the tyrosine-kinase receptor for hepatocyte growth factor, plays a critical role in the tumorigenesis of hepatocellular carcinoma (HCC). However, the underlying mechanism remains incompletely understood. The mature c-Met protein p190Met(αß) (consists of a α subunit and a ß subunit) is processed from pro-Met. Here we show that pro-Met is processed into p190Met(NC) by sarco/endoplasmic reticulum calcium-ATPase (SERCA) inhibitor thapsigargin. p190Met(NC) compensates for the degradation of p190Met(αß) and protects human HCC cells from apoptosis mediated by endoplasmic reticulum (ER) stress. In comparison with p190Met(αß), p190Met(NC) is not cleaved and is expressed as a single-chain polypeptide. Thapsigargin-initiated p190Met(NC) expression depends on the disturbance of ER calcium homeostasis. Once induced, p190Met(NC) is activated independent of hepatocyte growth factor engagement. p190Met(NC) contributes to sustained high basal activation of c-Met downstream pathways during ER calcium disturbance-mediated ER stress. Both p38 MAPK-promoted glucose-regulated protein 78 (GRP78) expression and sustained high basal activation of PI3K/Akt and MEK/ERK are involved in the cytoprotective function of p190Met(NC). Importantly, the expression of p190Met(NC) is detected in some HCC cases. Taken together, these data provide a potential mechanism to explain how c-Met promotes HCC cells survival in response to ER stress. We propose that context-specific processing of c-Met protein is implicated in HCC progression in stressful microenvironments.

The tyrosine kinase c-Met contributes to the pro-tumorigenic function of the p38 kinase in human bile duct cholangiocarcinoma cells.

Pro-tumorigenic function of the p38 kinase plays a critical role in human cholangiocarcinogenesis. However, the underlying mechanism remains incompletely understood. Here, we report that c-Met, the tyrosine kinase receptor for hepatocyte growth factor (HGF), contributes to the pro-tumorigenic ability of p38 in human cholangiocarcinoma cells. Both p38 and c-Met promote the proliferation and invasion of human cholangiocarcinoma cells. Importantly, inhibition or knockdown of p38 decreased the basal activation of c-Met. Tyrosine phosphatase inhibitor studies revealed that p38 promotes the activity of c-Met, at least in part, by inhibiting dephosphorylation of the receptor. Moreover, density enhanced phosphatase-1 (DEP-1) is involved in p38-mediated inhibiting dephosphorylation of c-Met. Furthermore, p38 inhibits the degradation of c-Met. Taken together, these data provide a potential mechanism to explain how p38 promotes human cholangiocarcinoma cell proliferation and invasion. We propose that the link between p38 and c-Met is implicated in the progression of human cholangiocarcinoma.

The suppressive role of p38 MAPK in cellular vacuole formation.

Vacuolization of the cytoplasm is one of the dramatic and frequently observed phenomena in various cell types. Cellular vacuoles occur spontaneously or via a wide range of inductive stimuli, but the molecular mechanism involved in this process remains largely unknown. In this study, we investigated the role of the p38 and JNK pathways in the formation of cytoplasmic vacuoles. We found that p38 and JNK agonist anisomycin abolishes spontaneous cytoplasmic vacuolization of HepG2 cells through p38 activation, but not through JNK activation. Importantly, blocking the activity of p38 or suppression the expression of p38 elicits cytoplasmic vacuoles formation in various cancer cells. Furthermore, cytoplasmic vacuoles induced by p38 blocking are derived from the perinuclear region. These observations provide direct evidence for a role of p38 signaling in regulating the formation of cytoplasmic vacuoles.

c-Met function requires N-linked glycosylation modification of pro-Met.

c-Met, the receptor for hepatocyte growth factor (HGF), is cell surface tyrosine kinase that controls cancer cell growth, survival, invasion, and metastasis. Post-translational modification, such as glycosylation, plays an essential role in regulating the function of cell surface molecules. Whether glycosylation modification regulates the enzymatic properties of c-Met is unknown. In this study, we investigated the effect of glycosylation on the function of c-Met. We found that c-Met is an N-linked glycosylated protein. Both pro-Met and p145Met (the ß subunit of mature c-Met) have N-linked glycosylation. Glycosylation inhibitor studies revealed that the N-glycosylation modification of p145Met is from pro-Met, but not due to the further modification of pro-Met. Importantly, blocking the N-glycosylation targets pro-Met to cytoplasm and initiates its phosphorylation independent of HGF engagement. Nonglycosylated pro-Met activates c-Met downstream pathways to a certain extent to compensate for the degradation of p145Met induced by glycosylation blocking-mediated endoplasmic reticulum (ER) stress.

p28(GANK) prevents degradation of Oct4 and promotes expansion of tumor-initiating cells in hepatocarcinogenesis.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is believed to arise from tumor-initiating cells (T-ICs), although little is known about their stem cell-like properties. METHODS: We quantified levels of p28(GANK) (Gankyrin), OV6, and Oct4 in 130 human HCC samples using immunohistochemistry. Magnetic-activated cell sorting was used to isolate OV6+ HCC cells. T-IC properties were evaluated by quantitative reverse-transcription polymerase chain reaction, flow cytometry, and spheroid formation. We used a coimmunoprecipitation assay to study interactions among p28(GANK), Oct4, and WWP2. Tumorigenicity and pulmonary metastasis were examined in nonobese diabetic and severe combined immunodeficient mice. RESULTS: In HCC samples, high levels of p28(GANK) correlated with expansion of OV6+ tumor cells; the combination of high levels of p28(GANK) and OV6 was associated with progression of HCC. p28(GANK) was predominantly expressed in liver T-ICs, isolated by magnetic sorting, and undifferentiated primary HCC spheroids. Increased levels of p28(GANK) in T-ICs increased their percentages in HCC samples, expression of stem cell genes, self-renewal potential, chemoresistance in vitro, and tumorigenicity and ability to develop into pulmonary metastases in mice. Conversely, knockdown of p28(GANK) reduced their T-IC properties. p28(GANK) likely activates liver T-ICs by impeding ubiquitination and degradation of the transcription factor Oct4 by WWP2. In support of this concept, levels of p28(GANK) correlated with those of Oct4 in HCC samples. CONCLUSIONS: p28(GANK) activates and maintains liver T-ICs in HCCs by preventing degradation of Oct4. Inhibitors of p28(GANK) might therefore be developed to inactivate T-ICs and slow tumor progression.

High expression of proline-rich tyrosine kinase 2 is associated with poor survival of hepatocellular carcinoma via regulating phosphatidylinositol 3-kinase/AKT pathway.

BACKGROUND: The peritumoral environment has been implicated to be important in the process of metastasis and recurrence in hepatocellular carcinoma (HCC). Our aims were to assess the prognostic value of proline-rich tyrosine kinase 2 (Pyk2) in HCC and investigate related molecular mechanism. METHODS: Expression of Pyk2 was tested by immunohistochemistry in tissue microarrays containing 141 paired HCC samples. Correlation between Pyk2 and vascular endothelial growth factor (VEGF) expression in clinical samples was analyzed by Spearman rank correlation. Matrigel invasion, anchorage-independent growth assay and immunoblotting were performed to study the effect of Pyk2 on the invasion and progression of HCC cells and phosphoinositide 3-kinase (PI3K)/AKT pathway activation. RESULTS: Higher Pyk2 density in both tumor and peritumor was associated with lower overall survival (P = 0.044; P = 0.041, respectively), serum AFP levels > 1,000 ng/ml (P = 0.013; P = 0.032, respectively) and postoperative distant metastasis (both P < 0.001). However, only higher peritumoral Pyk2 density was related to lower disease-free survival (P = 0.014) and vascular invasion (P = 0.035). A significant correlation between Pyk2 and VEGF density in tumor or peritumoral liver tissue was observed (r = 0. 3133, P = 0.0002; r = 0.5176, P < 0.0001, respectively). Immunoblotting showed that Pyk2 activated PI3K-AKT pathway to upregulate VEGF expression in HL-7702, SMMC-7721 and HepG2 cells. CONCLUSIONS: High Pyk2, especially peritumoral Pyk2 was associated with poor survival, disease recurrence, and metastasis in HCC. PI3K-AKT pathway was involved in Pyk2-mediated VEGF expression during HCC progression and invasion.

[Phosphorylation of eukaryotic initiation factor 2-alpha inhibits cisplatin-mediated apoptosis of hepatocellular carcinoma cells].

OBJECTIVE: To investigate whether the phosphorylation (functionally inhibitive) of eukaryotic initiation factor 2-alpha (eIF2-a) affects the molecular mechanism of cisplatin-induced cellular apoptosis in human hepatocellular carcinoma (HCC). METHODS: The human HCC cultured cell lines SMMC-7221 and HepG2 were treated with cisplatin alone (controls; 24 h) or in combination with pre-transfection of a dominant-negative eIF2-a mutant (eIF2aS51A) or pre-exposure to an eIF2-a-specific phosphatase inhibitor (salubrinal) to decrease or increase the phosphorylation level, respectively. Changes in expression of apoptosis markers were quantitatively and qualitatively assessed by flow cytometry and western blot analysis. The significance of differences among groups was assessed by analysis of variance testing and of differences between groups was assessed by t-test. RESULTS: Cisplatin treatment induced the appropriate functional-inhibitive phosphorylation of eIF2-a on serine 51. Cisplatin treatment (10 mg/ml) induced significant apoptosis in the eIF2aS51A pre-transfected SMMC-7721 (control: 21.7 +/- 1.5% vs. 50.7 +/- 2.1%, t = 19.454, P less than 0.05) and HepG2 (21.0 +/- 1.0% vs. 57.3 +/- 2.1%, t = 27.250, P less than 0.05). Salubrinal pre-treatment significantly inhibited the cisplatin (15 mg/ml)-induced apoptosis in SMMC-7721 (control: 50.3 +/- 2.5% vs. 16.3 +/- 2.1%, t = 18.031, P less than 0.05) and HepG2 (42.0 +/- 2.6% vs. 12.0 +/- 2.0%, t = 15.667, P less than 0.05). CONCLUSION: Phosphorylation of eIF2-a may act to inhibit cisplatin-induced apoptosis of HCC.

Vascular mimicry induced by m6A mediated IGFL2-AS1/AR axis contributes to pazopanib resistance in clear cell renal cell carcinoma.

Metastatic clear cell renal cell carcinoma (ccRCC) is a lethal sub-type of kidney cancer. Vascular mimicry (VM) has been postulated as an alternative route to supply tumors with nutrients, playing key role in tumor development. Whether VM development is linked to pazopanib efficacy, however, remains unclear. Here, our in vitro and in vivo models identified that VM development was profoundly increased in pazopanib resistant ccRCC as compared to the sensitive controls, which was due to the activation of IGFL2-AS1/AR/TWIST1 signaling. IGFL2-AS1, a m6A modified long coding RNA, was demethylated by METTL3/METTL14 complex and stabilized owing to its failing recognition by YTHDF2 upon chronic pazopanib treatment. Further mechanistic dissection illustrated that IGFL2-AS1 physically interacted with the 5'-UTR AR mRNA and neutralized the negative regulation of 5'-uORF (upstream open reading frame) on AR translation. Indeed, IGFL2-AS1 short of AR binding region failed to promote AR expression, VM formation and pazopanib resistance. In vivo xenografted mouse model also elucidated that inhibition of AR activity with enzalutamide or silence of IGFL2-AS1 with siRNAs all led to retarded growth of pazopanib resistant ccRCC tumors. Together, these results suggest that IGFL2-AS1 may represent a key player to mediate pazopanib-induced VM formation of ccRCC cells via regulating AR expression and targeting this newly identified IGFL2-AS1/AR signaling may help us to better suppress ccRCC VM formation and to increase the therapeutic efficacy of pazopanib.

Activation of PKR/eIF2α signaling cascade is associated with dihydrotestosterone-induced cell cycle arrest and apoptosis in human liver cells.

Androgen receptor (AR) signaling plays an important role in the development and progression of several liver diseases, including hepatocellular carcinoma (HCC) and non-alcoholic fatty liver disease (NAFLD). Dihydrotestosterone (DHT) is the active metabolite of the major circulating androgen, testosterone. In this study, we investigated the effect of DHT on human liver cells. We found that DHT not only induces cell cycle arrest but also initiates apoptosis in androgen-sensitive liver cells, such as SMMC-7721 and L02. Importantly, DHT/AR induces the activation of RNA-dependent protein kinase (PKR)/eukaryotic initiation factor-2 alpha (eIF2α) cascades in androgen-sensitive liver cells. PKR/eIF2α activation-induced growth arrest and DNA damage-inducible gene 153 (GADD153) and heat shock protein 27 (Hsp27) expression contribute to cell cycle arrest in response to DHT. It is notable that DHT administration results in androgen-sensitive liver cells apoptosis, at least in part, through PKR/eIF2α/GADD153 cascades. These results suggest that the androgen/AR pathway plays a pivotal role in liver cell growth and apoptosis regulating, whose deregulation might be involved in the pathogenesis of liver diseases.

Profound impact of gut homeostasis on chemically-induced pro-tumorigenic inflammation and hepatocarcinogenesis in rats.

BACKGROUND & AIMS: Due to its anatomic connection, the liver is constantly exposed to gut-derived bacterial products or metabolites. Disruption of gut homeostasis is associated with many human diseases. The aim of this study was to determine the role of gut homeostasis in initiation and progression of hepatocellular carcinoma (HCC). METHODS: Disruption of intestinal homeostasis by penicillin or dextran sulfate sodium (DSS) and its restoration by probiotics were applied in a diethylnitrosamine (DEN) model of rat hepatocarcinogenesis. RESULTS: Patients with liver cirrhosis and HCC had significantly increased serum endotoxin levels. Chronic DEN treatment of rats was associated with an imbalance of subpopulations of the gut microflora including a significant suppression of Lactobacillus species, Bifidobacterium species and Enterococcus species as well as intestinal inflammation. Induction of enteric dysbacteriosis or intestinal inflammation by penicillin or DSS, respectively, significantly promoted tumor formation. Administration of probiotics dramatically mitigated enteric dysbacteriosis, ameliorated intestinal inflammation, and most importantly, decreased liver tumor growth and multiplicity. Interestingly, probiotics not only inhibited the translocation of endotoxin, which bears pathogen-associated molecular patterns (PAMPs) but also the activation of damage-associated molecular patterns (DAMPs) such as high-mobility group box 1 (HMGB1). As a result, the production of pro- and anti-inflammatory cytokines was skewed in favor of a reduced tumorigenic inflammation in the liver. CONCLUSIONS: The data highlights the importance of gut homeostasis in the pathogenesis of HCC. Modulation of the gut microbiota by probiotics may represent a new avenue for therapeutic intervention to treat or prevent HCC development.

Silibinin ameliorates cisplatin-induced acute kidney injury via activating Nfe2l1-mediated antioxidative response to suppress the ROS/MAPK signaling pathway.

Cisplatin, a first-line chemotherapeutic agent commonly used to treat various solid tumors, induce severe adverse effects, especially nephrotoxicity, which largely limits its clinical application. However, the currently used measures to prevent nephrotoxicity are not ideal owing to the mechanisms underlying cisplatin-induced nephrotoxicity are not comprehensively understood. Herein, we examined the effects of silibinin on cisplatin-induced nephrotoxicity and found that silibinin exerted cytoprotection effects during cisplatin treatment in HEK293 cells and in a cisplatin-induced acute kidney injury (AKI) model. Mechanistically, silibinin ameliorated cisplatin-induced AKI via decreasing ROS-mediated MAPK signaling pathway activation, which was confirmed using the inhibitor N-acetylcysteine. Moreover, the protective effect of silibinin against cisplatin-induced ROS generation through the antioxidant transcription factor nuclear factor-erythroid 2-related factor 1 (Nfe2l1), rather than Nfe2l2, mediates HO1 expression. Furthermore, interference with the abundance of Nfe2l1 using siRNA or an overexpression plasmid enhanced or decreased the effect of cisplatin-induced apoptosis, respectively, in HEK293 cells. Interestingly, Nfe2l1 protein stability was more sensitive to cisplatin than that of Nfe2l2. More importantly, the mechanism that silibinin activates Nfe2l1-mediated antioxidant responses was confirmed in a cisplatin-induced AKI model. Silibinin rescued cisplatin-induced Nfe2l1 inhibition by regulating its transcription and post-translational modifications. Taken together, our results reveal a novel mechanism by which silibinin ameliorates cisplatin-induced AKI via activating Nfe2l1-mediated antioxidative response, which provides a new insights to protect patients receiving cisplatin-based cancer treatment against AKI.

Comprehensive Analysis Revealed the Potential Implications of m6A Regulators in Lung Adenocarcinoma.

Background: The biological significance of RNA N6-methyladenosine (m6A) decoration in tumorigenicity and progression has been highlighted in recent studies, but whether m6A modification plays a potential role in tumor microenvironment (TME) formation and immune regulation in lung adenocarcinoma (LUAD) remains unclear. Methods: m6A modification features were evaluated by analyzing the multi-omics features of 17 m6A regulators in over 1900 LUAD samples, and at the same time, the correlation between these modification patterns and TME characteristics was analyzed. An m6A score signature-based principal component analysis (PCA) algorithm was constructed to assess the prognosis and responses of individual patients to immunotherapeutic and targeted therapies. Results: Three different m6A modification patterns were determined in 1901 LUAD samples, which were found to be related to diverse clinical outcomes via different biological pathways. Based on the m6A score extracted from the m6A-associated signature genes, LUAD patients were separated into high- and low-m6A score groups. It was discovered that patients with high m6A scores had longer survival, lower tumor mutation loads, and low PD-L1/PDCD1/CTLA4/TAG3 expression level. In addition, LUAD patients with high m6A scores displayed lower IC50 to some targeted drugs, including nilotinib, erlotinib, imatinib, and lapatinib. Conclusion: m6A modification was significantly associated with the TME and clinical outcomes. These findings may help gain more insights into the role of m6A decoration in the molecular mechanism of LUAD, thus facilitating the development of more effective personalized treatment strategies.

The Potential Role of Voltage-Dependent Anion Channel in the Treatment of Parkinson's Disease.

Parkinson's disease (PD) is a neurodegenerative disease second only to Alzheimer's disease in terms of prevalence. Previous studies have indicated that the occurrence and progression of PD are associated with mitochondrial dysfunction. Mitochondrial dysfunction is one of the most important causes for apoptosis of dopaminergic neurons. Therefore, maintaining the stability of mitochondrial functioning is a potential strategy in the treatment of PD. Voltage-dependent anion channel (VDAC) is the main component in the outer mitochondrial membrane, and it participates in a variety of biological processes. In this review, we focus on the potential roles of VDACs in the treatment of PD. We found that VDACs are involved in PD by regulating apoptosis, autophagy, and ferroptosis. VDAC1 oligomerization, VDACs ubiquitination, regulation of mitochondrial permeability transition pore (mPTP) by VDACs, and interaction between VDACs and α-synuclein (α-syn) are all promising methods for the treatment of PD. We proposed that inhibition of VDAC1 oligomerization and promotion of VDAC1 ubiquitination as an effective approach for the treatment of PD. Previous studies have proven that the expression of VDAC1 has a significant change in PD models. The expression levels of VDAC1 are decreased in the substantia nigra (SN) of patients suffering from PD compared with the control group consisting of normal individuals by using bioinformatics tools. VDAC2 is involved in PD mainly through the regulation of apoptosis. VDAC3 may have a similar function to VDAC1. It can be concluded that the functional roles of VDACs contribute to the therapeutic strategy of PD.

EGCG Enhances the Chemosensitivity of Colorectal Cancer to Irinotecan through GRP78-MediatedEndoplasmic Reticulum Stress.

This study aimed to explore the role of GRP78-mediated endoplasmic reticulum stress (ERS) in the synergistic inhibition of colorectal cancer by epigallocatechin-3-gallate (EGCG) and irinotecan (IRI). Findings showed that EGCG alone or in combination with irinotecan can significantly promote intracellular GRP78 protein expression, reduce mitochondrial membrane potential and intracellular ROS in RKO and HCT 116 cells, and induce cell apoptosis. In addition, glucose regulatory protein 78 kDa (GRP78) is significantly over-expressed in both colorectal cancer (CRC) tumor specimens and mouse xenografts. The inhibition of GRP78 by small interfering RNA led to the decrease of the sensitivity of CRC cells to the drug combination, while the overexpression of it by plasmid significantly increased the apoptosis of cells after the drug combination. The experimental results in the mouse xenografts model showed that the combination of EGCG and irinotecan could inhibit the growth of subcutaneous tumors of HCT116 cells better than the two drugs alone. EGCG can induce GRP78-mediated endoplasmic reticulum stress and enhance the chemo-sensitivity of colorectal cancer cells when coadministered with irinotecan.

Cuproptosis-Related MiR-21-5p/FDX1 Axis in Clear Cell Renal Cell Carcinoma and Its Potential Impact on Tumor Microenvironment.

As a newly identified type of programmed cell death, cuproptosis may have an impact on cancer development, including clear cell renal cell carcinoma (ccRCC). Herein, we first noticed that the expression levels of cuproptosis regulators exhibited a tight correlation with the clinicopathological characteristics of ccRCC. The cuproptosis-sensitive sub-type (CSS), classified via consensus clustering analysis, harbored a higher overall survival rate compared to the cuproptosis-resistant sub-type (CRS), which may have resulted from the differential infiltration of immune cells. FDX1, the cuproptosis master regulator, was experimentally determined as a tumor suppressor in ccRCC cells by suppressing the cell growth and cell invasion of ACHN and OSRC-2 cells in a cuproptosis-dependent and -independent manner. The results from IHC staining also demonstrated that FDX1 expression was negatively correlated with ccRCC tumor initiation and progression. Furthermore, we identified the miR-21-5p/FDX1 axis in ccRCC and experimentally verified that miR-21-5p directly binds the 3'-UTR of FDX1 to mediate its degradation. Consequently, a miR-21-5p inhibitor suppressed the cell growth and cell invasion of ACHN and OSRC-2 cells, which could be compensated by FDX1 knockdown, reinforcing the functional linkage between miR-21-5p and FDX1 in ccRCC. Finally, we evaluated the ccRCC tumor microenvironment under the miR-21-5p/FDX1 axis and noted that this axis was strongly associated with the infiltration of immune cells such as CD4+ T cells, Treg cells, and macrophages, suggesting that this signaling axis may alter microenvironmental components to drive ccRCC progression. Overall, this study constructed the miR-21-5p/FDX1 axis in ccRCC and analyzed its potential impact on the tumor microenvironment, providing valuable insights to improve current ccRCC management.