Hepatitis B virus-regulated growth of liver cancer cells occurs through the microRNA-340-5p-activating transcription factor 7-heat shock protein A member 1B axis

Tumor Dormancy and Reactivation: The Role of Heat Shock Proteins

Tumors are a heterogeneous group of cell masses originating in various organs or tissues. The cellular composition of the tumor cell mass interacts in an intricate manner, influenced by humoral, genetic, molecular, and tumor microenvironment cues that dictate tumor growth or suppression. As a result, tumors undergo a period of a dormant state before their clinically discernible stage, which surpasses the clinical dormancy threshold. Moreover, as a genetically imprinted strategy, early-seeder cells, a distinct population of tumor cells, break off to dock nearby or extravasate into blood vessels to secondary tissues, where they form disseminated solitary dormant tumor cells with reversible capacity. Among the various mechanisms underlying the dormant tumor mass and dormant tumor cell formation, heat shock proteins (HSPs) might play one of the most important roles in how the dormancy program plays out. It is known that numerous aberrant cellular processes, such as malignant transformation, cancer cell stemness, tumor invasion, metastasis, angiogenesis, and signaling pathway maintenance, are influenced by the HSPs. An accumulating body of knowledge suggests that HSPs may be involved in the angiogenic switch, immune editing, and extracellular matrix (ECM) remodeling cascades, crucial genetically imprinted strategies important to the tumor dormancy initiation and dormancy maintenance program. In this review, we highlight the biological events that orchestrate the dormancy state and the body of work that has been conducted on the dynamics of HSPs in a tumor mass, as well as tumor cell dormancy and reactivation. Additionally, we propose a conceptual framework that could possibly underlie dormant tumor reactivation in metastatic relapse.

Little things with significant impact: miRNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has developed into one of the most lethal, aggressive, and malignant cancers worldwide. Although HCC treatment has improved in recent years, the incidence and lethality of HCC continue to increase yearly. Therefore, an in-depth study of the pathogenesis of HCC and the search for more reliable therapeutic targets are crucial to improving the survival quality of HCC patients. Currently, miRNAs have become one of the hotspots in life science research, which are widely present in living organisms and are non-coding RNAs involved in regulating gene expression. MiRNAs exert their biological roles by suppressing the expression of downstream genes and are engaged in various HCC-related processes, including proliferation, apoptosis, invasion, and metastasis. In addition, the expression status of miRNAs is related to the drug resistance mechanism of HCC, which has important implications for the systemic treatment of HCC. This paper reviews the regulatory role of miRNAs in the pathogenesis of HCC and the clinical applications of miRNAs in HCC in recent years.

The pathogenesis of liver cancer and the therapeutic potential of bioactive substances

Liver cancer is the third most common cause of cancer-related deaths in the world and has become an urgent problem for global public health. Bioactive substances are widely used for the treatment of liver cancer due to their widespread availability and reduced side effects. This review summarizes the main pathogenic factors involved in the development of liver cancer, including metabolic fatty liver disease, viral infection, and alcoholic cirrhosis, and focuses on the mechanism of action of bioactive components such as polysaccharides, alkaloids, phenols, peptides, and active bacteria/fungi. In addition, we also summarize transformation methods, combined therapy and modification of bioactive substances to improve the treatment efficiency against liver cancer, highlighting new ideas in this field.

Emerging roles of activating transcription factor (ATF) family members in tumourigenesis and immunity: Implications in cancer immunotherapy

Activating transcription factors, ATFs, are a group of bZIP transcription factors that act as homodimers or heterodimers with a range of other bZIP factors. In general, ATFs respond to extracellular signals, indicating their important roles in maintaining homeostasis. The ATF family includes ATF1, ATF2, ATF3, ATF4, ATF5, ATF6, and ATF7. Consistent with the diversity of cellular processes reported to be regulated by ATFs, the functions of ATFs are also diverse. ATFs play an important role in cell proliferation, apoptosis, differentiation and inflammation-related pathological processes. The expression and phosphorylation status of ATFs are also related to neurodegenerative diseases and polycystic kidney disease. Various miRNAs target ATFs to regulate cancer proliferation, apoptosis, autophagy, sensitivity and resistance to radiotherapy and chemotherapy. Moreover, ATFs are necessary to maintain cell redox homeostasis. Therefore, deepening our understanding of the regulation and function of ATFs will provide insights into the basic regulatory mechanisms that influence how cells integrate extracellular and intracellular signals into genomic responses through transcription factors. Under pathological conditions, especially in cancer biology and response to treatment, the characterization of ATF dysfunction is important for understanding how to therapeutically utilize ATF2 or other pathways controlled by transcription factors. In this review, we will demonstrate how ATF1, ATF2, ATF3, ATF4, ATF5, ATF6, and ATF7 function in promoting or suppressing cancer development and identify their roles in tumour immunotherapy.

Multiomics Analysis of Endocytosis upon HBV Infection and Identification of SCAMP1 as a Novel Host Restriction Factor against HBV Replication

Hepatitis B virus (HBV) infection remains a major global health problem and the primary cause of cirrhosis and hepatocellular carcinoma (HCC). HBV intrusion into host cells is prompted by virus–receptor interactions in clathrin-mediated endocytosis. Here, we report a comprehensive view of the cellular endocytosis-associated transcriptome, proteome and ubiquitylome upon HBV infection. In this study, we quantified 273 genes in the transcriptome and 190 endocytosis-associated proteins in the proteome by performing multi-omics analysis. We further identified 221 Lys sites in 77 endocytosis-associated ubiquitinated proteins. A weak negative correlation was observed among endocytosis-associated transcriptome, proteome and ubiquitylome. We found 33 common differentially expressed genes (DEGs), differentially expressed proteins (DEPs), and Kub-sites. Notably, we reported the HBV-induced ubiquitination change of secretory carrier membrane protein (SCAMP1) for the first time, differentially expressed across all three omics data sets. Overexpression of SCAMP1 efficiently inhibited HBV RNAs/pgRNA and secreted viral proteins, whereas knockdown of SCAMP1 significantly increased viral production. Mechanistically, the EnhI/XP, SP1, and SP2 promoters were inhibited by SCAMP1, which accounts for HBV X and S mRNA inhibition. Overall, our study unveils the previously unknown role of SCAMP1 in viral replication and HBV pathogenesis and provides cumulative and novel information for a better understanding of endocytosis in response to HBV infection.

Sublethal heat treatment promotes breast cancer metastasis and its molecular mechanism revealed by quantitative proteomic analysis

Radiofrequency ablation (RFA) is a frequently used thermal ablation technique for breast tumors. The study aimed to identify the effect of sublethal heat treatment on biological function of breast cancer cells and reveal its potential molecular mechanism. The expression profile of dysregulated proteins in sublethal heat treated breast cancer cells was analyzed by quantitative proteomic analysis. The differentially expressed proteins in the sublethal heat treated breast cancer were identified. The potential biological functions of these proteins were evaluated. The proliferation and invasion ability of breast cancer cells were enhanced after sublethal heat treatment. The expression profile of proteins in sublethal heat treated breast cancer cells was abundant, and most of which were newly discovered. A total of 206 differentially expressed proteins were identified. Among them, 101 proteins were downregulated while 105 proteins were upregulated. GO and KEGG analysis indicated that various systems were involved in the process of sublethal heat treatment including cancer, immune system, et al. Immunohistochemistry staining showed that the expression of Heat shock protein 1B, NOB1 and CRIP1 was highly expressed while the expression of BCLAF1 was lower in sublethal heat treated group. The proliferation and invasion ability of breast cancer cells were enhanced after sublethal heat treatment. Sublethal heat treatment caused gene alterations in cancer and immune system. Heat shock protein 1B, NOB1 and CRIP1 were upregulated while BCLAF1 was downregulated in breast cancer after sublethal heat treatment.

Establishment of a Zebrafish Xenograft Model for in Vivo Investigation of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a unique malignant tumor of the head and neck. Despite higher survival rates by the combination of radiotherapy and chemotherapy, the recurrence or metastasis of NPC still occurs at about 10%. Therefore, there is urgent demand to develop more effective in vivo models for preclinical trials to investigate the mechanisms of NPC development and progression and to explore better treatment approaches. In this study, we transplanted human NPC CNE1 cells into zebrafish embryos to establish a xenograft model of NPC, where the proliferation and invasion behaviors of NPC cells were investigated in vivo. Combining in vitro and in vivo analyses, we found that activating transcription factor 7 (ATF7) was involved in the occurrence and development of NPC regulated by peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1). The zebrafish NPC xenograft model established here thereby provides an in vivo tool for exploring the occurrence and development of NPC, which may help to identify new tumor markers and develop new therapeutic strategies for the treatment of NPC.

Antiviral Therapy Reduces Mortality in Hepatocellular Carcinoma Patients with Low-Level Hepatitis B Viremia

Background and Aims

Although antiviral treatment has been shown to reduce mortality in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) patients with high HBV-DNA levels, it is still unclear whether it is useful in reducing mortality in patients with low HBV-DNA levels.

Methods

A retrospective analysis of 756 HBV-associated HCC patients at the Beijing Ditan Hospital with HBV-DNA levels < 500 IU/mL was conducted between January 2008 and June 2017. Patients were divided into antiviral and non-antiviral groups based on whether they received nucleos(t)ide analogue (NA) treatment when they were diagnosed with HCC in our hospital for the first time. We used 1:4 frequency matching by age, gender, tumor size, Barcelona Clinic Liver Cancer (BCLC) staging, anti-tumor therapy, cirrhosis, diabetes, and hyperlipoidemia to compare the antiviral (n = 366) and non-antiviral (n = 100) groups. A Cox multivariate regression analysis was employed to evaluate the effects of NA therapy on the hazard ratio (HR), and the Kaplan–Meier survival curve was used to determine the mortality risk in patients with HCC. A Log rank test was performed to analyze the effects of NA therapy on the survival rate of patients with HCC.

Results

After propensity score matching, the 1-, 3-, and 5-year overall survival (OS) rates for the antiviral and non-antiviral groups were 82.5%, 68.6%, and 52.2%, and 61.0%, 51.0%, and 38.0%, respectively. The l-year progression-free survival (PFS) rates for the two groups were 68.0% and 47.0%, respectively. The OS of the antiviral group was significantly higher than that of the control group (P < 0.001, P = 0.001, and P = 0.013, respectively). The 1-year PFS for the antiviral group was also significantly better than that for the non-antiviral groups (P = 0.005). After adjusting for confounding prognostic factors in the Cox model, the HR of 5-year death after antiviral treatment was 0.721 (95% confidence interval [CI], 0.530–0.980, P = 0.037). Antiviral therapy is an independent protective factor for 5-year mortality in patients with HCC and low-level viremia.

Conclusion

Antiviral therapy significantly reduced mortality in HCC patients with low HBV-DNA levels.

LncRNA PCNAP1 Promotes Hepatoma Cell Proliferation through Targeting miR-340-5p and is Associated with Patient Survival

Hepatocellular carcinoma (HCC) is one of the most common malignancies and causes poor outcome. Dysregulation of long noncoding RNA (lncRNA) is involved in HCC. Upregulation of the lncRNA PCNAP1 has been reported to promote HBV-infectious HCC growth, but its clinical significance and underlying mechanisms in HCC development remain unclear. Here, we report that PCNAP1 expression is increased in both HBV-infectious and noninfectious HCC tissues compared with matched normal tissues, and its upregulation correlates with poor survival rates of HCC patients. Furthermore, we found that PCNAP1 promotes HCC cell proliferation through acting as a competitive endogenous RNA (ceRNA) to sponge miR-340-5p, which has been reported to directly inhibit ATF7 expression in HCC cells. Moreover, the PCNAP1/miR-340-5p/ATF7 signaling associates with the poor survival rates of HCC patients. Collectively, our findings suggest that the PCNAP1/miR-340-5p/ATF7 signaling may be a potential biomarker for the prognosis of HCC patients and a potential therapeutic target for HCC.

Overexpression of microRNA-340-5p Ameliorates Inflammatory Response and Intracellular Survival of Mycobacterium Tuberculosis in Alveolar Type II Cells

Background

The importance of microRNAs (miRs) has been documented in infections. This study estimated the role of miR-340-5p in Mycobacterium tuberculosis (Mtb)-infected alveolar type II cells.

Methods

The microarray of GEO database was analyzed to find the differentially expressed miRs caused by Mtb infection, and miR-340-5p was selected as the research object. The effects of Mtb infection on A549 cells were studied by MTT, CFU, EdU, flow cytometry and ELISA assays. miR-340-5p expression was altered in Mtb-infected A549 cells. The downstream target of miR-340-5p was found by bioinformatics analysis and verified by the rescue experiment. The pathways regulated by miR-340-5p and its target gene were further studied.

Results

Mtb infection suppressed the activity of A549 cells and promoted the release of inflammatory factors. Mtb infection inhibited miR-340-5p expression. Overexpression of miR-340-5p enhanced the resistance of A549 cells to Mtb infection. Moreover, miR-340-5p targeted TMED7. Overexpression of TMED7 reversed the protective effect of miR-340-5p on Mtb-infected A549 cells. miR-340-5p inhibited the activation of NF-κB by targeting TMED7.

Conclusion

miR-340-5p inhibits the activation of NF-κB by targeting TMED7, thus alleviating the injury of A549 cells caused by Mtb infection. This study may offer a novel approach to Mtb infection.

MicroRNA signature in liver cancer

Liver cancer is the 7^th utmost frequent neoplasm and the 4^th principal source of cancer deaths. This malignancy is linked with several environmental and lifestyle-related factors emphasizing the role of epigenetics in its pathogenesis. MicroRNAs (miRNAs) have been regarded as potent epigenetic mechanisms partaking in the pathogenesis of liver cancer. Dysregulation of miRNAs has been related with poor outcome of patients with liver cancer. In the current manuscript, we provide a concise review of the results of recent studies about the role of miRNAs in the progression of liver cancer and their diagnostic and prognostic utility.

miR-340-5p inhibits sheep adipocyte differentiation by targeting ATF7

Several microRNAs (miRNAs) have been identified to play roles in adipocyte differentiation. However, little is known about their involvement in the differentiation of ovine intramuscular adipocytes. Here, the role of one such miRNA, miR-340-5p, in ovine adipocyte differentiation was investigated. Stromal vascular (SV) cells were isolated from skeletal muscle tissues of 1-month-old lambs and induced to differentiate into mature adipocytes. miRNA mimics and inhibitors were used for miR-340-5p overexpression and knockdown assays. For overexpression and knockdown of activating transcription factor 7 (ATF7), lentivirus infection was performed. Luciferase reporter assay was performed to determine the relationship between miR-340-5p and ATF7. The expression of adipogenesis marker genes, PPARγ, C/EBPα, FABP4, ADIPOQ, and ACC, and formation of lipid droplets were detected after the overexpression and inhibition of miR-340-5p, or upon overexpression or knockdown of ATF7. miR-340-5p inhibited the expression of the marker genes and the formation of lipid droplets. ATF7 positively regulated the expression of the marker genes and the formation of lipids. Thus, ATF7 is the target of miR-340-5p in sheep. Overall, these findings indicate that miR-340-5p acts as an inhibitor of the differentiation of intramuscular adipocytes by targeting ATF7. Our study provides a new theoretical basis for improving sheep meat quality.

Identification of Cerebrospinal Fluid MicroRNAs Associated With Leptomeningeal Metastasis From Lung Adenocarcinoma

Background: Leptomeningeal metastasis (LM) has frequently been observed in patients with lung adenocarcinoma. So far, its diagnosis and disease course monitoring are still extremely difficult. Moreover, there is no effective treatment regimen for LM due to a lack knowledge on the molecular mechanism of LM. This study aimed to identify LM-related cerebrospinal fluid (CSF) miRNAs, which have potential value for diagnosing and monitoring LM and exploring the molecular mechanism.

Methods: CSF miRNAs were screened and verified by microarray analysis and quantitative real-time PCR (qRT-PCR) in LM patients with lung adenocarcinoma and non-LM controls, and the diagnostic performance of candidate miRNAs was evaluated. Then, candidate miRNAs in matched CSF samples from LM patients at diagnosis, after initial therapy, at relapse, and after salvage therapy, were analyzed to assess the relationship between CSF miRNAs and LM disease course. The effect of candidate miRNAs on proliferation, invasion, and migration of lung adenocarcinoma cell lines was assessed. The targeted genes of the candidate miRNA were predicted by TargetScan, miRDB, and miRTarbase online analysis tools. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to analyze the functional categories of predicted target genes.

Results: CSF miR-7975, miR-7977, and miR-7641 were screened and verified to be statistically significantly up-regulated in LM patients compared to non-LM controls. The three miRNAs, when combined, exhibited optimal diagnostic performance. Longitudinal data of CSF miR-7975 and miR-7977 correlated well with clinical courses of LM. Overexpression of miR-7977 promoted proliferation, migration, and invasion of lung adenocarcinoma cells. Moreover, 385 targeted genes of miR-7977 were predicted and were involved in various pathways related to cancer metastasis.

Conclusions: This study offers insights for future research of CSF miRNAs as robust tools for diagnosing and monitoring LM. It also reveals a novel pathway for exploration of underlying mechanisms of LM.

Profiling of tRNA Halves and YRNA Fragments in Serum and Tissue From Oral Squamous Cell Carcinoma Patients Identify Key Role of 5' tRNA-Val-CAC-2-1 Half

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck cancer and, as indicated by The Oral Cancer Foundation, kills at an alarming rate of roughly one person per hour. With this study, we aimed at better understanding disease mechanisms and identifying minimally invasive disease biomarkers by profiling novel small non-coding RNAs (specifically, tRNA halves and YRNA fragments) in both serum and tumor tissue from humans. Small RNA-Sequencing identified multiple 5' tRNA halves and 5' YRNA fragments that displayed significant differential expression levels in circulation and/or tumor tissue, as compared to control counterparts. In addition, by implementing a modification of weighted gene coexpression network analysis, we identified an upregulated genetic module comprised of 5' tRNA halves and miRNAs (miRNAs were described in previous study using the same samples) with significant association with the cancer trait. By consequently implementing miRNA-overtargeting network analysis, the biological function of the module (and by "guilt by association," the function of the 5' tRNA-Val-CAC-2-1 half) was found to involve the transcriptional targeting of specific genes involved in the negative regulation of the G1/S transition of the mitotic cell cycle. These findings suggest that 5' tRNA-Val-CAC-2-1 half (reduced in serum of OSCC patients and elevated in the tumor tissue) could potentially serve as an OSCC circulating biomarker and/or target for novel anticancer therapies. To our knowledge, this is the first time that the specific molecular function of a 5'-tRNA half is specifically pinpointed in OSCC.

Epigenetic Alterations of Heat Shock Proteins (HSPs) in Cancer

Heat shock proteins (HSPs) are associated with various physiological processes (protein refolding and degradation) involved in the responses to cellular stress, such as cytotoxic agents, high temperature, and hypoxia. HSPs are overexpressed in cancer cells and play roles in their apoptosis, invasion, proliferation, angiogenesis, and metastasis. The regulation or translational modification of HSPs is recognized as a therapeutic target for the development of anticancer drugs. Among the regulatory processes associated with HSP expression, the epigenetic machinery (miRNAs, histone modification, and DNA methylation) has key functions in cancer. Moreover, various epigenetic modifiers of HSP expression have also been reported as therapeutic targets and diagnostic markers of cancer. Thus, in this review, we describe the epigenetic alterations of HSP expression in cancer cells and suggest that HSPs be clinically applied as diagnostic and therapeutic markers in cancer therapy via controlled epigenetic modifiers.

Hepatitis B virus-regulated growth of liver cancer cells occurs through the microRNA-340-5p-activating transcription factor 7-heat shock protein A member 1B axis

Hepatocellular carcinoma (HCC) is a common cancer with poor prognosis. Hepatitis B virus (HBV) is one of the leading causes of HCC, but the precise mechanisms by which this infection promotes cancer development are not fully understood. Recently, miR‐340‐5p, a microRNA (miRNA) that has been identified as a cancer suppressor gene, was found to inhibit the migration and invasion of liver cancer cells. However, the effect of miR‐340‐5p on cell proliferation and apoptosis in HBV‐associated HCC remains unknown. In our study, we show that miR‐340‐5p plays an important role during HBV infection and hepatocellular carcinoma development. Specifically, this miRNA directly binds to the mRNA encoding activating transcription factor 7 (ATF7), a protein that both promotes cell proliferation and suppresses apoptosis through its interaction with heat shock protein A member 1B (HSPA1B). We further found that miR‐340‐5p is downregulated by HBV, which enhances ATF7 expression, leading to enhanced cell proliferation and inhibition of apoptosis. Notably, ATF7 is upregulated in HCC tissue, suggesting that HBV may target miR‐340‐5p in vivo to promote ATF7/HSPA1B‐mediated proliferation and apoptosis and regulate liver cancer progression. This work helps to elucidate the complex interactions between HBV and host miRNAs and further suggests that miR‐340‐5p may represent a promising candidate for the development of improved therapeutic strategies for HCC.