RCN1 induces sorafenib resistance and malignancy in hepatocellular carcinoma by activating c-MYC signaling via the IRE1α-XBP1s pathway

An integrated investigation of sulfotransferases (SULTs) in hepatocellular carcinoma and identification of the role of SULT2A1 on stemness

The cytosolic sulfotransferases (SULTs) are phase II conjugating enzymes, which are widely expressed in the liver and mainly mediate the sulfation of numerous xenobiotics and endogenous compounds. However, the role of various SULTs genes has not been reported in hepatocellular carcinoma (HCC). This study aims to analyze the expression and potential functional roles of SULTs genes in HCC and to identify the role of SULT2A1 in HCC stemness as well as the possible mechanism. We found that all of the 12 SULTs genes were differentially expressed in HCC. Moreover, clinicopathological features and survival rates were also investigated. Multivariate regression analysis showed that SULT2A1 and SULT1C2 could be used as independent prognostic factors in HCC. SULT1C4, SULT1E1, and SULT2A1 were significantly associated with immune infiltration. SULT2A1 deficiency in HCC promoted chemotherapy resistance and stemness maintenance. Mechanistically, silencing of SULT2A1 activated the AKT signaling pathway, on the one hand, promoted the expression of downstream stemness gene c-Myc, on the other hand, facilitated the NRF2 expression to reduce the accumulation of ROS, and jointly increased HCC stemness. Moreover, knockdown NR1I3 was involved in the transcriptional regulation of SULT2A1 in stemness maintenance. In addition, SULT2A1 knockdown HCC cells promoted the proliferation and activation of hepatic stellate cells (HSCs), thereby exerting a potential stroma remodeling effect. Our study revealed the expression and role of SULTs genes in HCC and identified the contribution of SULT2A1 to the initiation and progression of HCC.

Downregulation of RCN1 inhibits esophageal squamous cell carcinoma progression and M2 macrophage polarization

Reticulocalbin 1 (RCN1) is a calcium-binding protein involved in the regulation of calcium homeostasis in the endoplasmic reticulum. The aim of this study was to explore the clinical value and biological role of RCN1 in esophageal squamous cell carcinoma (ESCC). In addition, we investigated the effect of RCN1 on the polarization of tumor-associated macrophages (TAMs). The GSE53625 dataset from the Gene Expression Omnibus database was used to analyze the expression of RCN1 mRNA and its relationship with clinical value and immune cell infiltration. Immunohistochemistry was used to validate the expression of RCN1 and its correlation with clinicopathological characteristics. Subsequently, transwell and cell scratch assays were conducted to evaluate the migration and invasion abilities of ESCC cells. The expression levels of epithelial-mesenchymal transition (EMT)-related proteins were evaluated by western blot, while apoptosis was detected by flow cytometry and western blot. Additionally, qRT‒PCR was utilized to evaluate the role of RCN1 in macrophage polarization. RCN1 was significantly upregulated in ESCC tissues and was closely associated with lymphatic metastasis and a poor prognosis, and was an independent prognostic factor for ESCC in patients. Knockdown of RCN1 significantly inhibited the migration, invasion, and EMT of ESCC cells, and promoted cell apoptosis. In addition, RCN1 downregulation inhibited M2 polarization. RCN1 is upregulated in ESCC patients and is negatively correlated with patient prognosis. Knocking down RCN1 inhibits ESCC progression and M2 polarization. RCN1 can serve as a potential diagnostic and prognostic indicator for ESCC, and targeting RCN1 is a very promising therapeutic strategy.

Oxyberberine sensitizes liver cancer cells to sorafenib via inhibiting NOTCH1-USP7-c-Myc pathway

BACKGROUND

Sorafenib is the first-line therapy for patients with advanced-stage HCC, but its clinical cure rate is unsatisfactory due to adverse reactions and drug resistance. Novel alternative strategies to overcome sorafenib resistance are urgently needed. Oxyberberine (OBB), a major metabolite of berberine in vivo, exhibits potential antitumor potency in various human malignancies, including liver cancer. However, it remains unknown whether and how OBB sensitizes liver cancer cells to sorafenib.

METHODS

Cell viability, trypan blue staining and flow cytometry assays were employed to determine the synergistic effect of OBB and sorafenib on killing HCC cells. PCR, western blot, co-immunoprecipitation and RNA interference assays were used to decipher the mechanism by which OBB sensitizes sorafenib. HCC xenograft models and clinical HCC samples were utilized to consolidate our findings.

RESULTS

We found for the first time that OBB sensitized liver cancer cells to sorafenib, enhancing its inhibitory effect on cell growth and induction of apoptosis in vitro. Interestingly, we observed that OBB enhanced the sensitivity of HCC cells to sorafenib by reducing ubiquitin-specific peptidase 7 (USP7) expression, a well-known tumor-promoting gene. Mechanistically, OBB inhibited notch homolog 1-mediated USP7 transcription, leading to the downregulation of V-Myc avian myelocytomatosis viral oncogene homolog (c-Myc), which synergized with sorafenib to suppress liver cancer. Furthermore, animal results showed that cotreatment with OBB and sorafenib significantly inhibited the tumor growth of liver cancer xenografts in mice.

CONCLUSIONS

These results indicate that OBB enhances the sensitivity of liver cancer cells to sorafenib through inhibiting notch homolog 1-USP7-c-Myc signaling pathway, which potentially provides a novel therapeutic strategy for liver cancer to improve the effectiveness of sorafenib.

Systematic integration of molecular and clinical approaches in HCV-induced hepatocellular carcinoma

BACKGROUND

MicroRNAs (miRNAs) play a crucial role in gene expression and regulation, with dysregulation of miRNA function linked to various diseases, including hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). There is still a gap in understanding the regulatory relationship between miRNAs and mRNAs in HCV-HCC. This study aimed to investigate the function and effects of persistent HCV-induced miRNA expression on gene regulation in HCC.

METHODS

MiRNA array data were used to identify differentially expressed miRNAs and their targets, and miRNAs were analyzed via DIANA for KEGG pathways, gene ontology (GO) functional enrichment, and Ingenuity Pathways Analysis (IPA) for hepatotoxicity, canonical pathways, associated network functions, and interactive networks.

RESULTS

Seventeen miRNAs in L-HCV and 9 miRNAs in S-HCV were differentially expressed, and 5 miRNAs in L-HCV and 5 miRNAs in S-HCV were significantly expressed in liver hepatocellular carcinoma (LIHC) tumors. Grouped miRNA survival analysis showed that L-HCV miRNAs were associated with survival in LIHC, and miRNA‒mRNA targets regulated viral carcinogenesis and cell cycle alteration through cancer pathways in LIHC. MiRNA-regulated RCN1 was suppressed through miRNA-oncogene interactions, and suppression of RCN1 inhibited invasion and migration in HCC.

CONCLUSION

Persistent HCV infection induced the expression of miRNAs that act as tumor suppressors by inhibiting oncogenes in HCC. RCN1 was suppressed while miRNAs were upregulated, demonstrating an inverse relationship. Therefore, hsa-miR-215-5p, hsa-miR-10b-5p, hsa-let-7a-5p and their target RCN1 may be ideal biomarkers for monitoring HCV-HCC progression.

Anti-tumor therapy of glycyrrhetinic acid targeted liposome co-delivery of doxorubicin and berberine for hepatocellular carcinoma

During the development of hepatocellular carcinoma (HCC), hepatic stellate cells undergo activation and transform into cancer-associated fibroblasts (CAFs) due to the influence of tumor cells. The interaction between CAFs and tumor cells can compromise the effectiveness of chemotherapy drugs and promote tumor proliferation, invasion, and metastasis. This study explores the potential of glycyrrhetinic acid (GA)-modified liposomes (lip-GA) as a strategy for co-delivery of berberine (Ber) and doxorubicin (Dox) to treat HCC. The characterizations of liposomes, including particle size, zeta potential, polydispersity index, stability and in vitro drug release, were investigated. The study evaluated the anti-proliferation and anti-migration effects of Dox&Ber@lip-GA on the Huh-7 + LX-2 cell model were through MTT and wound-healing assays. Additionally, the in vivo drug distribution and anti-tumor efficacy were investigated using the H22 + NIH-3T3-bearing mouse model. The results indicated that Dox&Ber@lip-GA exhibited a nanoscale particle size, accumulated specifically in the tumor region, and was efficiently taken up by tumor cells. Compared to other groups, Dox&Ber@lip-GA demonstrated higher cytotoxicity and lower migration rates. Additionally, it significantly reduced the deposition of extracellular matrix (ECM) and inhibited tumor angiogenesis, thereby suppressing tumor growth. In conclusion, Dox&Ber@lip-GA exhibited superior anti-tumor effects both in vitro and in vivo, highlighting its potential as an effective therapeutic strategy for combating HCC.

CYB5R1 is a potential biomarker that correlates with stemness and drug resistance in gastric cancer

BACKGROUND

Drug resistance is a major obstacle in the treatment of gastric cancers (GC). In recent years, the prognostic value of the mRNA expression-based stemness score (mRNAss) across cancers has been reported. We intended to search for the key genes associated with Cancer stem cells (CSCs) and drug resistance.

METHODS

All GC samples from The Cancer Genome Atlas (TCGA) were then divided into low- and high-mRNAss groups based on the median value of mRNAss. A weighted correlation network analysis (WCGNA) was used to identify co-expressed genes related to mRNAss groups. Differential gene expression analysis with Limma was performed in the GSE31811. The correlations between CYB5R1 and the immune cells and macrophage infiltration were analyzed by TIMER database. Spheroid formation assay was used to evaluate the stemness of gastric cancer cells, and transwell assay was used to detect the invasion and migration ability of gastric cancer cells.

RESULTS

GC patients with high mRNAss values had a worse prognosis than those with low mRNAss values. 584 genes were identified by WGCNA analysis. 668 differentially expressed genes (DEGs) (|logFC|>1) with 303 down-regulated and 365 up-regulated were established in drug-effective patients compared to controls. TCGA-STAD samples were divided into 3 subtypes based on 303 down-regulated genes. CYB5R1 was a potential biomarker that correlated with the response to drugs in GC (AUC=0.83). CYB5R1 participated in drug resistance and tumorigenesis through NFS1 in GC.

CONCLUSIONS

Our study highlights the clinical importance of CYB5R1 in GC and the CYB5R1-NFS1 signaling-targeted therapy might be a feasible strategy for the treatment of GC.

RCN1 deficiency inhibits oral squamous cell carcinoma progression and THP-1 macrophage M2 polarization

Reticulocalbin 1 (RCN1), a calcium-binding protein located in the endoplasmic reticulum (ER) lumen, contains six conserved regions. Its main functions include maintaining intracellular homeostasis and regulating cell proliferation and apoptosis, and it plays an important role in the development of various tumours. However, the exact function of RCN1 in oral squamous cell carcinoma (OSCC) is not fully understood. Therefore, the aim of this study was to investigate the effects of RCN1 on the biological behaviour of OSCC and the regulation of tumour-associated macrophage (TAM) polarization. The expression of RCN1 in OSCC and normal oral mucosa was evaluated through bioinformatics analysis and immunohistochemical staining. The growth, migration, and invasion of OSCC cells were observed after knockdown of RCN1 using CCK-8 and Transwell assays. Apoptosis was detected by flow cytometry. The effect of tumour cell-derived RCN1 on the polarization of THP-1 macrophages was investigated by establishing a coculture model of THP-1 macrophages and OSCC cells. Additionally, changes in the expression levels of relevant proteins were detected using Western blotting. The upregulation of RCN1 in tumour tissues compared to normal oral mucosal tissues is associated with a poor prognosis and can be utilized as a prognostic indicator for OSCC. Knockdown of RCN1 inhibited the proliferation, migration, and invasion of OSCC cells. Additionally, knockdown of RCN1 in Cal-27 and SCC-25 cells resulted in inhibition of the M2 polarization of THP-1 macrophages. RCN1 knockdown inhibits OSCC progression and M2 macrophage polarization. Targeting RCN1 may be a promising approach for OSCC treatment.

Downregulation of RCN1 promotes pyroptosis in acute myeloid leukemia cells

Reticulocalbin-1 (RCN1) is expressed aberrantly and at a high level in various tumors, including acute myeloid leukemia (AML), yet its impact on AML remains unclear. In this study, we demonstrate that RCN1 knockdown significantly suppresses the viability of bone marrow mononuclear cells (BMMNCs) from AML patients but does not affect the viability of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSCs) from healthy donors in vitro. Downregulation of RCN1 also reduces the viability of AML cell lines. Further studies showed that the RCN1 knockdown upregulates type I interferon (IFN-1) expression and promotes AML cell pyroptosis through caspase-1 and gasdermin D (GSDMD) signaling. Deletion of the mouse Rcn1 gene inhibits the viability of mouse AML cell lines but not the hematopoiesis of mouse bone marrow. In addition, RCN1 downregulation in human AML cells significantly inhibited tumor growth in the NSG mouse xenograft model. Taken together, our results suggest that RCN1 may be a potential target for AML therapy.

MYC in liver cancer: mechanisms and targeted therapy opportunities

MYC, a major oncogenic transcription factor, regulates target genes involved in various pathways such as cell proliferation, metabolism and immune evasion, playing a critical role in the tumor initiation and development in multiple types of cancer. In liver cancer, MYC and its signaling pathways undergo significant changes, exerting a profound impact on liver cancer progression, including tumor proliferation, metastasis, dedifferentiation, metabolism, immune microenvironment, and resistance to comprehensive therapies. This makes MYC an appealing target, despite it being previously considered an undruggable protein. In this review, we discuss the role and mechanisms of MYC in liver physiology, chronic liver diseases, hepatocarcinogenesis, and liver cancer progression, providing a theoretical basis for targeting MYC as an ideal therapeutic target for liver cancer. We also summarize and prospect the strategies for targeting MYC, including direct and indirect approaches to abolish the oncogenic function of MYC in liver cancer.

The unfolded protein response links ER stress to cancer-associated thrombosis

Thrombosis is a common complication of advanced cancer, yet the cellular mechanisms linking malignancy to thrombosis are poorly understood. The unfolded protein response (UPR) is an ER stress response associated with advanced cancers. A proteomic evaluation of plasma from patients with gastric and non-small cell lung cancer who were monitored prospectively for venous thromboembolism demonstrated increased levels of UPR-related markers in plasma of patients who developed clots compared with those who did not. Release of procoagulant activity into supernatants of gastric, lung, and pancreatic cancer cells was enhanced by UPR induction and blocked by antagonists of the UPR receptors inositol-requiring enzyme 1α (IRE1α) and protein kinase RNA-like endoplasmic reticulum kinase (PERK). Release of extracellular vesicles bearing tissue factor (EVTFs) from pancreatic cancer cells was inhibited by siRNA-mediated knockdown of IRE1α/XBP1 or PERK pathways. Induction of UPR did not increase tissue factor (TF) synthesis, but rather stimulated localization of TF to the cell surface. UPR-induced TF delivery to EVTFs was inhibited by ADP-ribosylation factor 1 knockdown or GBF1 antagonism, verifying the role of vesicular trafficking. Our findings show that UPR activation resulted in increased vesicular trafficking leading to release of prothrombotic EVTFs, thus providing a mechanistic link between ER stress and cancer-associated thrombosis.

XBP1 as a novel molecular target to attenuate drug resistance in hepatocellular carcinoma

INTRODUCTION

Despite improvements in clinical management of hepatocellular carcinoma (HCC), prognosis remains poor with a 5-year survival rate less than 40%. Drug resistance in HCC makes it challenging to treat; therefore, it is imperative to develop new therapeutic strategies. Higher expression of X-box binding protein 1 (XBP1) in tumor cells is highly correlated with poor prognosis. In tumor cells, XBP1 modulates the unfolded protein response (UPR) to restore homeostasis in endoplasmic reticulum. Targeting XBP1 could be a promising therapeutic strategy to overcome HCC resistance and improve the survival rate of patients.

AREAS COVERED

This review provides the recent evidence that indicates XBP1 is involved in HCC drug resistance via DNA damage response, drug inactivation, and inhibition of apoptosis. In addition, the potential roles of XBP1 in inducing resistance in HCC cells were highlighted, and we showed how its inhibition could sensitize tumor cells to controlled cell death.

EXPERT OPINION

Due to the diversity in molecular mechanism of multidrug-resistance, targeting one specific pathway is inadequate. XBP1 inhibition could be a potential therapeutic target to overcome verity of resistance mechanisms. The main function of this transcription factor in HCC treatment response is an attractive area for further studies and should be discussed more.

Identification and verification of eight cancer-associated fibroblasts related genes as a prognostic signature for head and neck squamous cell carcinoma

Cancer-associated fibroblasts (CAFs) can exert their immunosuppressive effects by secreting various effectors that are involved in the regulation of tumor-infiltrating immune cells as well as other immune components in the tumor immune microenvironment (TIME), thereby promoting tumorigenesis, progression, metastasis, and drug resistance. Although a large number of studies suggest that CAFs play a key regulatory role in the development of head and neck squamous cell carcinoma (HNSCC), there are limited studies on the relevance of CAFs to the prognosis of HNSCC. In this study, we identified a prognostic signature containing eight CAF-related genes for HNSCC by univariate Cox analysis, lasso regression, stepwise regression, and multivariate Cox analysis. Our validation in primary cultures of CAFs from human HNSCC and four human HNSCC cell lines confirmed that these eight genes are indeed characteristic markers of CAFs. Immune cell infiltration differences analysis between high-risk and low-risk groups according to the eight CAF-related genes signature hinted at CAFs regulatory roles in the TIME, further revealing its potential role on prognosis. The signature of the eight CAF-related genes was validated in different independent validation cohorts and all showed that it was a valid marker for prognosis. The significantly higher overall survival (OS) in the low-risk group compared to the high-risk group was confirmed by Kaplan-Meier (K-M) analysis, suggesting that the signature of CAF-related genes can be used as a non-invasive predictive tool for HNSCC prognosis. The low-risk group had significantly higher levels of tumor-killing immune cell infiltration, as confirmed by CIBERSORT analysis, such as CD8⁺ T cells, follicular helper T cells, and Dendritic cells (DCs) in the low-risk group. In contrast, the level of infiltration of pro-tumor cells such as M0 macrophages and activated Mast cells (MCs) was lower. It is crucial to delve into the complex mechanisms between CAFs and immune cells to find potential regulatory targets and may provide new evidence for subsequently targeted immunotherapy. These results suggest that the signature of the eight CAF-related genes is a powerful indicator for the assessment of the TIME of HNSCC. It may provide a new and reliable potential indicator for clinicians to predict the prognosis of HNSCC, which may be used to guide treatment and clinical decision-making in HNSCC patients. Meanwhile, CAF-related genes are expected to become tumor biomarkers and effective targets for HNSCC.

Advances of cancer-associated fibroblasts in liver cancer

Liver cancer is one of the most common malignant tumors worldwide, it is ranked sixth in incidence and fourth in mortality. According to the distinct origin of malignant tumor cells, liver cancer is mainly divided into hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). Since most cases are diagnosed at an advanced stage, the prognosis of liver cancer is poor. Tumor growth depends on the dynamic interaction of various cellular components in the tumor microenvironment (TME). As the most abundant components of tumor stroma, cancer-associated fibroblasts (CAFs) have been involved in the progression of liver cancer. The interplay between CAFs and tumor cells, immune cells, or vascular endothelial cells in the TME through direct cell-to-cell contact or indirect paracrine interaction, affects the initiation and development of tumors. Additionally, CAFs are not a homogeneous cell population in liver cancer. Recently, single-cell sequencing technology has been used to help better understand the diversity of CAFs in liver cancer. In this review, we mainly update the knowledge of CAFs both in HCC and CCA, including their cell origins, chemoresistance, tumor stemness induction, tumor immune microenvironment formation, and the role of tumor cells on CAFs. Understanding the context-dependent role of different CAFs subsets provides new strategies for precise liver cancer treatment.