The role of microRNA in the resistance to treatment of hepatocellular carcinoma

Ropivacaine combined with sorafenib attenuates hepatocellular carcinoma cell proliferation and metastasis by inhibiting the miR-224/HOXD10 axis

OBJECTIVE

The development of drug resistance in hepatocellular carcinoma (HCC) cells limits the effectiveness of sorafenib (Sor). However, the regulatory mechanisms underlying the effects of the combination Sor and ropivacaine (Rop) on HCC cells remain unclear.

METHODS

miR-224 and HOXD10 mRNA expression in HCC cells was analyzed using qRT-PCR. CCK-8, Transwell assays and tumor formation experiments in nude mice were used to assess HCC cell proliferation, migration, and invasion. Migration of HCC cells was also analyzed using a cell scratch assay. Hematoxylin and eosin staining was used to detect tumor area.

RESULTS

miR-224 expression profoundly increased in HepG2 and Huh7 cells. Treatment with Rop and/or Sor blocked miR-244 expression, especially the combination treatment. Transfection of miR-224 mimic increased HCC cell proliferation and tumor size in nude mice, and migration and invasion in vitro in the presence of Rop and Sor compared to the negative control mimic. Dual-luciferase reporter assays showed that HOXD10 was targeted by miR-224. HOXD10 protein expression and was markedly reduced in HepG2 and Huh7 cells. Rop and/or Sor treatment increased HOXD10 protein expression, particularly the combination treatment. miR-224 negatively regulated HOXD10 expression in HCC cells treated with Rop and Sor. Transfection-mediated silencing of HOXD10 increased HCC cell proliferation, migration, and invasion in the presence of Rop and Sor compared with negative control transfection.

CONCLUSION

The combination of Rop and Sor attenuates HCC cell proliferation and metastasis via the miR-224/HOXD10 axis.

Restoring microRNA-34a overcomes acquired drug resistance and disease progression in human breast cancer cell lines via suppressing the ABCC1 gene

PURPOSE

Breast cancer is one of the leading types of cancer diagnosed in women. Despite the improvements in chemotherapeutic cure strategies, drug resistance is still an obstacle leading to disease aggressiveness. The small non-coding RNA molecules, miRNAs, have been implicated recently to be involved as regulators of gene expression through the silencing of mRNA targets that contributed to several cellular processes related to cancer metastasis. Hence, the present study aimed to investigate the beneficial role and mechanism of miRNA-34a-based gene therapy as a novel approach for conquering drug resistance mediated by ATP-binding cassette (ABC) transporters in breast cancer cells, besides exploring the associated invasive behaviors.

MATERIAL AND METHODS

Bioinformatics tools were used to predict miRNA ABC transporter targets by tracking the ABC transporter pathway. After the establishment of drug-resistant breast cancer MCF-7 and MDA-MB-231 sublines, cells were transfected with the mimic or inhibitor of miRNA-34a-5p. The quantitative expression of genes involved in drug resistance was performed by QRT-PCR, and the exact ABC transporter target specification interaction was confirmed by dual-luciferase reporter assay. Furthermore, flow cytometric analysis was utilized to determine the ability of miRNA-34a-treated cells against doxorubicin uptake and accumulation in cell cycle phases. The spreading capability was examined by colony formation, migration, and wound healing assays. The apoptotic activity was estimated as well.

RESULTS

Our findings firstly discovered the mechanism of miRNA-34a-5p restoration as an anti-drug-resistant molecule that highly significantly attenuates the expression of ABCC1 via the direct targeting of its 3'- untranslated regions in resistant breast cancer cell lines, with a significant increase of doxorubicin influx by MDA-MB-231/Dox-resistant cells. Additionally, the current data validated a significant reduction of metastatic potentials upon miRNA-34a-5p upregulation in both types of breast cancer-resistant cells.

CONCLUSION

The ectopic expression of miRNA-34a ameliorates the acquired drug resistance and the migration properties that may eventually lead to improved clinical strategies and outcomes for breast cancer patients. Additionally, miRNA-34a could be monitored as a diagnostic/prognostic biomarker for resistant conditions.

What are the changes in the hotspots and frontiers of microRNAs in hepatocellular carcinoma over the past decade?

BACKGROUND

Emerging research suggests that microRNAs (miRNAs) play an important role in the development of hepatocellular carcinoma (HCC). A comprehensive analysis of recent research concerning miRNAs in HCC development could provide researchers with a valuable reference for further studies.

AIM

To make a comprehensive analysis of recent studies concerning miRNAs in HCC.

METHODS

All relevant publications were retrieved from the Web of Science Core Collection database. Bibliometrix software, VOSviewer software and CiteSpace software were used to visually analyze the distribution by time, countries, institutions, journals, and authors, as well as the keywords, burst keywords and thematic map.

RESULTS

A total of 9426 publications on this topic were found worldwide. According to the keywords analysis, we found that the studies of miRNAs focused on their expression level, effects, and mechanisms on the biological behaviour of HCC. Keywords bursting analysis showed that in the early years (2013-2017), "microRNA expression", "gene expression", "expression profile", "functional polymorphism", "circulating microRNA", "susceptibility" and "mir 21" started to attract attention. In the latest phase (2018-2022), the hot topics turned to "sorafenib resistance", "tumor microenvironment" and so on.

CONCLUSION

This study provides a comprehensive overview of the role of miRNAs in HCC development based on bibliometric analysis. The hotspots in this field focus on miRNAs expression level, effects, and mechanisms on the biological behavior of HCC. The frontiers turned to sorafenib resistance, tumor microenvironment and so on.

MicroRNA based combinatorial therapy against TKIs resistant CML by inactivating the PI3K/Akt/mTOR pathway: a review

Chronic myeloid leukemia (CML) is characterized by presence of Philadelphia chromosome, which harbors BCR-ABL oncogene responsible for encoding BCR-ABL oncoprotein. This oncoprotein interferes with cellular signaling pathways, resulting in tumor progression. Among these pathways, PI3K/Akt/mTOR pathway is significantly upregulated in CML. Tyrosine kinase inhibitors (TKIs) are current standard therapy for CML, and they have shown remarkable efficacy. However, emergence of TKIs drug resistance has necessitated investigation of novel therapeutic approaches. Components of PI3K/Akt/mTOR pathway have emerged as attractive targets in this context, as this pathway is known to be activated in TKIs-resistant CML cells/patients. Inhibiting this pathway may provide a complementary approach to improving TKIs' efficacy and treatment outcomes. Given previous research indicating that miRNAs play an inhibitory role in cancer, current study used computational tools to identify miRNAs that specifically target pathway's core components. A comprehensive analysis was performed, resulting in identification of 111 miRNAs that potentially target PI3K/Akt/mTOR pathway. From this extensive list, 7 miRNAs was selected for further investigation based on their consistent downregulation across leukemia subtypes. Except for hsa-miR-199a-3p, remaining six miRNAs have been extensively studied in acute myeloid leukemia (AML). Given high similarity between AML and CML, it is believed that six miRNAs which are not studied in context of CML may also be advantageous for curing chemoresistance in CML. Building upon this knowledge, it is reasonable to speculate that a combination therapy approach involving use of miRNAs alongside TKIs may offer improved therapy for TKIs-resistant CML compared to TKIs monotherapy alone.

The pivotal role of EMT-related noncoding RNAs regulatory axes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a major health problem worldwide, being the leading cause of cancer-related deaths, with limited treatment options, especially in its advanced stages. Tumor resistance is closely associated with the activation of the EMT phenomenon and its reversal, being modulated by different molecules, including noncoding RNAs (ncRNAs). Noncoding RNAs have the potential to function as both tumor suppressors and oncogenic molecules, controlling the malignant potential of HCC cells. Basically, these molecules circulate in the tumor microenvironment, encapsulated in exosomes. Their impact on cell biology is more significant than originally expected, which makes related research rather complex. The temporal and spatial expression patterns, precise roles and mechanisms of specific ncRNAs encapsulated in exosomes remain primarily unknown in different stages of the disease. This review aims to highlight the recent advances in ncRNAs related to EMT and classifies the described mechanism as direct and indirect, for a better summarization. Moreover, we provide an overview of current research on the role of ncRNAs in several drug resistance-related pathways, including the emergence of resistance to sorafenib, doxorubicin, cisplatin and paclitaxel therapy. Nevertheless, we comprehensively discuss the underlying regulatory mechanisms of exosomal ncRNAs in EMT-HCC via intercellular communication pathways.

The emerging role of miRNA-122 in infectious diseases: Mechanisms and potential biomarkers

microRNAs (miRNAs) are small, non-coding RNA molecules that play crucial regulatory roles in numerous cellular processes. Recent investigations have highlighted the significant involvement of miRNA-122 (miR-122) in the pathogenesis of infectious diseases caused by diverse pathogens, encompassing viral, bacterial, and parasitic infections. In the context of viral infections, miR-122 exerts regulatory control over viral replication by binding to the viral genome and modulating the host's antiviral response. For instance, in hepatitis B virus (HBV) infection, miR-122 restricts viral replication, while HBV, in turn, suppresses miR-122 expression. Conversely, miR-122 interacts with the hepatitis C virus (HCV) genome, facilitating viral replication. Regarding bacterial infections, miR-122 has been found to regulate host immune responses by influencing inflammatory cytokine production and phagocytosis. In Vibrio anguillarum infections, there is a significant reduction in miR-122 expression, contributing to the pathophysiology of bacterial infections. Toll-like receptor 14 (TLR14) has been identified as a novel target gene of miR-122, affecting inflammatory and immune responses. In the context of parasitic infections, miR-122 plays a crucial role in regulating host lipid metabolism and immune responses. For example, during Leishmania infection, miR-122-containing extracellular vesicles from liver cells are unable to enter infected macrophages, leading to a suppression of the inflammatory response. Furthermore, miR-122 exhibits promise as a potential biomarker for various infectious diseases. Its expression level in body fluids, particularly in serum and plasma, correlates with disease severity and treatment response in patients affected by HCV, HBV, and tuberculosis. This paper also discusses the potential of miR-122 as a biomarker in infectious diseases. In summary, this review provides a comprehensive and insightful overview of the emerging role of miR-122 in infectious diseases, detailing its mechanism of action and potential implications for the development of novel therapeutic strategies.

Hsa-miR-223-3p participates in the process of anthracycline-induced cardiomyocyte damage by regulating NFIA gene

Irreversible cardiomyopathy was caused by the therapeutic of anthracyclines in the chemotherapy of cancers. The cell apoptosis and autophagy were induced by anthracyclines in AC16 cells. MiR-223-3p ascends in anthracycline-treated AC16, but the expression of nuclear factor I-A (NFIA) was specifically down-regulated. However, the underlying molecular mechanism between NFIA and miR-223-3p is unclear now in AC16 cells. In our research, NFIA expression was dampened in AC16 cells by miR-223-3p mimics. Additionally, miR-223-3p knockdown hindered the apoptosis and autophagy in anthracycline-treated AC16. Furthermore, NFIA was predicted and verified as a miR-223-3p's downstream target and rescued the functions of miR-223-3p. These findings illustrated that miR-223-3p advances anthracycline-stimulated cardiomyocyte damage progression by targeting NFIA, implying the promising therapeutic function of miR-223-3p on cardiomyocyte damage in cancer patients.

An Insight into the Arising Role of MicroRNAs in Hepatocellular Carcinoma: Future Diagnostic and Therapeutic Approaches

Hepatocellular carcinoma (HCC) constitutes a frequent highly malignant form of primary liver cancer and is the third cause of death attributable to malignancy. Despite the improvement in the therapeutic strategies with the exploration of novel pharmacological agents, the survival rate for HCC is still low. Shedding light on the multiplex genetic and epigenetic background of HCC, such as on the emerging role of microRNAs, is considered quite promising for the diagnosis and the prediction of this malignancy, as well as for combatting drug resistance. MicroRNAs (miRNAs) constitute small noncoding RNA sequences, which play a key role in the regulation of several signaling and metabolic pathways, as well as of pivotal cellular functions such as autophagy, apoptosis, and cell proliferation. It is also demonstrated that miRNAs are significantly implicated in carcinogenesis, either acting as tumor suppressors or oncomiRs, while aberrations in their expression levels are closely associated with tumor growth and progression, as well as with local invasion and metastatic dissemination. The arising role of miRNAs in HCC is in the spotlight of the current scientific research, aiming at the development of novel therapeutic perspectives. In this review, we will shed light on the emerging role of miRNAs in HCC.

Autophagy orchestrates resistance in hepatocellular carcinoma cells

Treatment resistance is one of the major barriers for therapeutic strategies in hepatocellular carcinoma (HCC). Many studies have indicated that chemotherapy and radiotherapy induce autophagy machinery (cell protective autophagy) in HCC cells. In addition, many experiments report a remarkable crosstalk between treatment resistance and autophagy pathways. Thus, autophagy could be one of the key factors enabling tumor cells to hinder induced cell death after medical interventions. Therefore, extensive research on the molecular pathways involved in resistance induction and autophagy have been conducted to achieve the desired therapeutic response. The key molecular pathways related to the therapy resistance are TGF-β, MAPK, NRF2, NF-κB, and non-coding RNAs. In addition, EMT, drug transports, apoptosis evasion, DNA repair, cancer stem cells, and hypoxia could have considerable impact on the hepatoma cell's response to therapies. These mechanisms protect tumor cells against various treatments and many studies have shown that each of them is connected to the molecular pathways of autophagy induction in HCC. Hence, autophagy inhibition may be an effective strategy to improve therapeutic outcome in HCC patients. In this review, we further highlight how autophagy leads to poor response during treatment through a complex molecular network and how it enhances resistance in primary liver cancer. We propose that combinational regimens of approved HCC therapeutic protocols plus autophagy inhibitors may overcome drug resistance in HCC therapy.

Silencing lncRNA HCG18 regulates GPX4-inhibited ferroptosis by adsorbing miR-450b-5p to avert sorafenib resistance in hepatocellular carcinoma

Ferroptosis is potential to relieve drug resistance in hepatocellular carcinoma (HCC). Glutathione peroxidase 4 (GPX4) is a critical modulator of ferroptosis. This study discussed the mechanism of GPX4-inhibited ferroptosis in sorafenib resistance in HCC. HCG18 in HCC cells was detected. Sorafenib resistant (SR) cell line Huh7-SR cells were treated with sorafenib (0, 2.5, 5, 7.5, 10 μM). After silencing HCG18 in Huh7-SR cells, cell activity, proliferation and apoptosis were detected. The levels of iron, the concentration of MDA, GSH and lipid reactive oxygen species (ROS) were measured to evaluate the ferroptosis. The downstream mechanism of HCG18 was predicted and verified. Huh7-SR cells were infected with lentivirus sh-HCG18 to establish xenograft tumor model. HCG18 was elevated in HCC cells and associated with sorafenib resistance. Silencing HCG18 inhibited cell proliferation, promoted apoptosis, and impaired sorafenib resistance. Ferroptosis was inhibited in Huh7-SR cells, while silencing HCG18 inhibited sorafenib resistance by promoting ferroptosis. GPX4 overexpression averted the promotion of sh-HCG18 on ferroptosis, thereby reducing sorafenib resistance. HCG18 sponged miR-450b-5p to regulate GPX4. Collectively, Silencing HCG18 inhibits GPX4 by binding to miR-450b-5p, promotes GPX4-inhibited ferroptosis, and averts sorafenib resistance in HCC.

Comparative effectiveness of interventional therapeutic modalities for unresectable hepatocellular carcinoma: A systematic review and network meta‑analysis

It is unclear whether hepatic artery infusion chemotherapy (HAIC) or transcatheter arterial chemoembolization (TACE) is more efficient in the combination therapy of hepatocellular carcinoma (HCC). Head-to-head comparisons among HAIC-related therapies are lacking. For this network meta-analysis, PubMed, EMBASE and Cochrane Library databases were searched up to April 1, 2022. Randomized controlled trials (RCTs) were eligible if they evaluated the use or prolongation of TACE or HAIC in patients with advanced HCC and reported or collected survival data. A network meta-analysis was performed to synthesize data and make direct and indirect comparisons between treatments. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to explore the efficacy of various treatment options on overall survival (OS), odds ratios (ORs) with 95% CI were used for overall response rate (ORR), whereas risk ratios (RRs) with 95% CI were used for serious adverse events (SAEs). The analysis of 7 trials including a total of 1,073 patients found that sorafenib with HAIC-oxaliplatin improved survival (HR=0.33, 95% CI: 0.25-0.44); the ORR was also improved in patients treated with sorafenib plus HAIC-oxaliplatin and sorafenib plus PF-HAIC (OR=22.18, 95% CI: 10.69-52.56; and OR=2.72, 95% CI: 1.43-5.36, respectively). The incidence of liver injury was elevated in patients treated with sorafenib plus TACE (OR=5.93, 95% CI: 2.70-15.41). However, no differences in the incidences of other SAEs were identified among the treatment groups. The present meta-analysis provides preliminary evidence for the comparative safety and efficacy of HAIC and TACE combined with sorafenib, and indicates the dominance of HAIC-oxaliplatin in HCC interventional therapy. However, high-quality RCTs are required to further confirm the efficacy of HAIC-oxaliplatin. The present study has been registered with PROSPERO (registration no. CRD42021288497).

miR-15a and miR-20b sensitize hepatocellular carcinoma cells to sorafenib through repressing CDC37L1 and consequent PPIA downregulation

Sorafenib is a classical targeted drug for the treatment of advanced hepatocellular carcinoma (HCC), but intrinsic resistance severely limited its therapeutic effects. In the present study, we aimed to identify crucial genes in HCC cells that affect sorafenib resistance by a CRISPR/Cas9 genome-scale screening. The results indicated that the deficiency of miR-15a and miR-20b contributed to sorafenib resistance, whereas exogenous expression of miR-15a and miR-20b enhanced sorafenib sensitivity of HCC cells by cell viability, colony formation, and flow cytometry analyses. Further analyses revealed that cell division cycle 37 like 1 (CDC37L1) as a common target of miR-15a and 20b, was negatively regulated by the two miRNAs and could enhance sorafenib resistance of HCC cells in vitro and in vivo. Mechanistically, CDC37L1, as a cochaperone, effectively increased the expression of peptidylprolyl isomerase A (PPIA) through strengthening the binding between heat shock protein 90 (HSP90) and PPIA. The results from immunohistochemical staining of a HCC tissue microarray revealed a positive association between CDC37L1 and PPIA expression, and high expression of CDC37L1 and PPIA predicted worse prognosis of HCC patients after sorafenib therapy. Taken together, our findings reveal crucial roles of miR-15a, miR-20b, CDC37L1, and PPIA in sorafenib response of HCC cells. These factors may serve as therapeutic targets and predict prognosis for HCC treated with sorafenib.

miR-382-5p promotes cell invasion in hepatocellular carcinoma by targeting PTEN to activate PI3K/Akt signaling pathway

Purpose

This study aimed at investigating miR-382-5p expression in tissues and cell lines with hepatocellular carcinoma (HCC), its effects on the invasion of HCC cells, and related mechanisms.

Methods

miR-382-5p expression in HCC tissues, adjacent tissues, cell lines of normal hepatic cells, and HCC cells were detected by qRT-PCR, indicating its upregulation or downregulation in HCC cell lines (Hep3B and HCCLM3). The effect of miR-382-5p on cell invasion was observed by the Transwell experiment. The targeting relationship of miR-382-5p and the phosphatase and tensin homolog (PTEN) was analyzed using bioinformatics tools and the luciferase reporter gene assay. The correlation between miR-382-5p and PTEN was analyzed with Spearman correlation analysis. PTEN expression was observed after upregulation and downregulation of miR-382-5p expression. The effect of miR-382-5p on the expression of key proteins in PI3K/Akt signaling pathway was determined by Western blot.

Results

miR-382-5p expression was upregulated in both HCC tissues and cell lines (both P<0.05). Upregulation or downregulation of miR-382-5p significantly promoted or inhibited the invasion of cell lines, Hep3B, and HCCLM3. The luciferase reporter gene assay confirmed that PTEN is a target of miR-382-5p. The expressions of miR-382-5p and PTEN were negatively correlated (r=−0.742, P<0.001). Upregulation of PTEN expression by plasmid transfection can reverse the invasive effect of miR-382-5p on HCC cells. Upregulation of miR-382-5p can activate PI3K/Akt signaling pathway, and downregulation of miR-382-5p can inhibit PI3K/Akt signaling pathway.

Conclusions

miR-382-5p can activate the PI3K/Akt signaling pathway by targeting PTEN and promote HCC cell invasion.

miRNA Pattern in Hypoxic Microenvironment of Kidney Cancer—Role of PTEN

MicroRNAs are post-transcriptional regulators of gene expression, and disturbances of their expression are the basis of many pathological states, including cancers. The miRNA pattern in the context of tumor microenvironment explains mechanisms related to cancer progression and provides a potential target of modern therapies. Here we show the miRNA pattern in renal cancer focusing on hypoxia as a characteristic feature of the tumor microenvironment and dysregulation of PTEN, being a major tumor suppressor. Methods comprised the CRSPR/Cas9 mediated PTEN knockout in the Renca kidney cancer cell line and global miRNA expression analysis in both in vivo and in vitro (in normoxic and hypoxic conditions). The results were validated on human cancer models with distinct PTEN status. The increase in miR-210-3p in hypoxia was universal; however, the hypoxia-induced decrease in PTEN was associated with an increase in miR-221-3p, the loss of PTEN affected the response to hypoxia differently by decreasing miR-10b-5p and increasing miR-206-3p. In turn, the complete loss of PTEN induces miR-155-5p, miR-100-5p. Upregulation of miR-342-3p in knockout PTEN occurred in the context of the whole tumor microenvironment. Thus, effective identification of miRNA patterns in cancers must consider the specificity of the tumor microenvironment together with the mutations of key suppressors.

Ago-RIP Sequencing Identifies New MicroRNA-449a-5p Target Genes Increasing Sorafenib Efficacy in Hepatocellular Carcinoma

BACKGROUND: Patients with hepatocellular carcinoma (HCC) have very limited treatment options. For the last fourteen years, the multi-tyrosine kinase inhibitor sorafenib has been used as standard-of-care therapeutic agent in advanced HCC. Unfortunately, drug resistance develops in many cases. Therefore, we aimed to find a way to mitigate drug resistance and to improve the sorafenib efficacy in HCC cells. MicroRNAs play a significant role in targeting genes involved in tumor control suggesting microRNA/sorafenib combination therapy as a promising treatment option in advanced HCC. METHODS: MiR-449a-5p target genes were identified by Ago-RIP sequencing and validated by luciferase reporter assays and expression analyses. Target gene expression and survival data were analyzed in public HCC datasets. Tumor-relevant functional effects of miR-449a-5p and its target genes as well as their impact on the effects of sorafenib were analyzed using in vitro assays. An indirect transwell co-culture system was used to survey anti-angiogenic effects of miR-449a-5p. RESULTS: PEA15, PPP1CA and TUFT1 were identified as direct target genes of miR-449a-5p. Overexpression of these genes correlated with a poor outcome of HCC patients. Transfection with miR-449a-5p and repression of miR-449a-5p target genes inhibited cell proliferation and angiogenesis, induced apoptosis and reduced AKT and ERK signaling in HLE and Huh7 cells. Importantly, miR-449a-5p potentiated the efficacy of sorafenib in HCC cells via downregulation of PEA15, PPP1CA and TUFT1. CONCLUSIONS: This study provides detailed insights into the targetome and regulatory network of miR-449a-5p. Our results demonstrate for the first time that targeting PEA15, PPP1CA and TUFT1 via miR-449a overexpression could have significant implications in counteracting sorafenib resistance suggesting miR-449a-5p as a promising candidate for a microRNA/sorafenib combination therapy.

Functional and Clinical Significance of Dysregulated microRNAs in Liver Cancer

Simple Summary

Liver cancer has a high mortality rate. Here, we retrospectively discuss the current progress and dilemmas in the clinical research and treatment of liver cancer. We primarily focus on microRNAs because of their extremely high value in applications and research. We discuss whether microRNAs can be used for the development of better biomarkers and/or therapeutic drugs, and address the difficulties, requirements for improved diagnostic technologies, and side effects related to microRNA-based drugs.

Abstract

Liver cancer is the leading cause of cancer-related mortality in the world. This mainly reflects the lack of early diagnosis tools and effective treatment methods. MicroRNAs (miRNAs) are a class of non-transcribed RNAs, some of which play important regulatory roles in liver cancer. Here, we discuss microRNAs with key impacts on liver cancer, such as miR-122, miR-21, miR-214, and miR-199. These microRNAs participate in various physiological regulatory pathways of liver cancer cells, and their modulation can have non-negligible effects in the treatment of liver cancer. We discuss whether these microRNAs can be used for better clinical diagnosis and/or drug development. With the advent of novel technologies, fast, inexpensive, and non-invasive RNA-based biomarker research has become a new mainstream approach. However, the clinical application of microRNA-based markers has been limited by the high sequence similarity among them and the potential for off-target problems. Therefore, researchers particularly value microRNAs that are specific to or have special functions in liver cancer. These include miR-122, which is specifically expressed in the liver, and miR-34, which is necessary for the replication of the hepatitis C virus in liver cancer. Clinical treatment drugs have been developed based on miR-34 and miR-122 (MRX34 and Miravirsen, respectively), but their side effects have not yet been overcome. Future research is needed to address these weaknesses and establish a feasible microRNA-based treatment strategy for liver cancer.

miR-7, miR-10a and miR-143 Expression May Predict Response to Bevacizumab Plus Chemotherapy in Patients with Metastatic Colorectal Cancer

Purpose

Bevacizumab is a monoclonal antibody that binds to vascular endothelial growth factor A. It is currently used in combination with chemotherapy to treat metastatic colorectal cancer. This therapy is not equally effective in every patient; in some, mechanisms of resistance arise that remain poorly understood. The aim of the present work was to determine whether the expression of 26 miRNAs could be associated with the effectiveness of bevacizumab plus chemotherapy, with progression-free survival (PFS), and with overall survival (OS) in metastatic colorectal cancer.

Patients and Methods

Paraffin-embedded biopsies from 76 patients with metastatic colorectal cancer were collected to isolate miRNAs. The expression of 26 miRNAs was analyzed by quantitative RT-PCR. For the purpose of analysis, patients were classified as either “responders” (PFS ≥6 months since beginning treatment) or “non-responders” (PFS <6 months). For the analysis of PFS and OS, patients were classified into two groups using the median gene expression value as the cut-off point (“high” [≥50% percentile] or “low” [<50% percentile]). Time-to-event data were analyzed using the Kaplan–Meier method and compared by the log rank test. Cox regression was used to estimate hazard ratios (HR) and their 95% confidence intervals.

Results

miR-7-5p and miR-10a-5p were more strongly expressed in non-responders than responders (p=0.049 and p=0.043, respectively), and OS was poorer in patients showing these higher expression levels (HR=2.54, 95% CI 1.42–4.55, p=0. 001, and HR=1.81, 95% CI 1.02–3.20, p=0.039, respectively). The overexpression of miR-143-3p, however, was associated with a better prognosis and significantly better PFS (HR=0.57; 95% CI: 0.33–0.96; p=0.033).

Conclusion

High expression values for miR-7-5p and miR-10a-5p might be considered markers of a poorer prognosis in patients with metastatic colorectal cancer treated with bevacizumab plus chemotherapy, while the same for miR-143-3p might be a marker of better outcomes.

Research Progress on the Functions and Mechanism of circRNA in Cisplatin Resistance in Tumors

Cisplatin is a common chemotherapeutic drug that has been used to treat of numerous tumors, including testicular, lung, bladder, ovarian, liver and head and neck cancers. Although clinical chemotherapy based on cisplatin has shown a remarkable therapeutic effect, the resistance to cisplatin becomes increasingly obvious as a patient uses it for a prolonged period. It not only affects the prognosis of these tumors, but also causes the recurrence of cancer and decreases the overall survival rate. The development of cisplatin resistance involves several mechanisms, including DNA damage repair, ATP-binding cassette (ABC) transporter, autophagy, cancer stem cells (CSCs), epithelial-mesenchymal transition (EMT), and other related signaling pathways. Interestingly, these mechanisms have been found to be influenced by circular RNAs (circRNAs) to regulate tumor proliferation, invasion, chemosensitivity, and other biological behaviors in the tumor microenvironment (TME). In recent years, circRNAs in cisplatin resistance in tumors, especially lung cancer and gastric cancer, have gradually drawn peoples' attention. This review summarizes recent studies on the functions and mechanisms of circRNAs in cisplatin resistance. We emphasize that circRNA can be used as a promising target gene to improve drug resistance and therapeutic efficacy.

HGF/c-MET pathway contributes to cisplatin-mediated PD-L1 expression in hepatocellular carcinoma

Cisplatin has been reported to promote the expression of programmed cell death ligand-1 (PD-L1) in some cancer cells. However, the underlying mechanism through which PD-L1 is transcriptionally regulated by cisplatin in hepatocellular carcinoma (HCC) cells remains largely unknown. In the present study, we found that the expression of hepatocyte growth factor (HGF), p-Akt, p-ERK, and PD-L1 was increased in cisplatin-treated SNU-368 and SNU-739 cells. HGF stimulation also increased PD-L1 expression in these cells. Moreover, Inhibition of HGF/c-MET, PI3K/Akt, and MEK/ERK signaling pathways can dramatically block cisplatin or HGF-induced PD-L1 expression in SNU-368 and SNU-739 cells. In vivo, combination PHA665752 with cisplatin significantly reduced tumor weight with increased infiltration of CD8⁺  T cells in the tumor. Taken together, our study suggested that HGF/c-Met axis-induced the activation of PI3K/Akt and MEK/ERK pathways contributes to cisplatin-mediated PD-L1 expression. These findings may provide an alternative avenue for the treatment of HCC.

Transarterial chemoembolization plus sorafenib versus sorafenib for intermediate-advanced hepatocellular carcinoma: A meta-analysis comparing clinical outcomes

BACKGROUND

Hepatocellular carcinoma (HCC) ranks as the sixth most common cancer and the second leading cause of cancer-related death worldwide, local and systemic therapies are beneficial for those who have more advanced disease or are not suitable for radical treatment. We aim to investigate the clinical outcomes of transarterial chemoembolization (TACE) plus sorafenib compared with sorafenib monotherapy for intermediate-advanced HCC.

METHODS

A systematic search according to preferred reporting items for systematic reviews and meta-analyses guidelines in the PubMed database was conducted from inception to December 31, 2020 for published studies comparing survival outcomes and tumor response between TACE + sorafenib and sorafenib alone for intermediate-advanced HCC.

RESULTS

Five eligible cohort studies and a randomized controlled trial with a total of 3015 patients were identified. We found that the TACE + sorafenib group had a significantly better overall survival (OS) (hazard ratio, 0.77; 95% confidence interval [CI] 0.66-0.88, P < .001) than those treated with sorafenib. Median OS ranged from 7.0 to 22.0 months with TACE + sorafenib and from 5.9 to 18.0 months with sorafenib. The combination of TACE + sorafenib had a significantly better time to progression (hazard ratio, 0.74; 95% CI 0.65-0.82, P < .001) than those treated with sorafenib. Median time to progression ranged from 2.5 to 5.3 months with TACE + sorafenib and from 2.1 to 2.8 months with sorafenib. The results showed the TACE + sorafenib group had a higher disease control rate (log odds ratio, 0.52; 95% CI 0.25-0.80, P = .0002), objective response rate (log odds ratio, 0.85; 95% CI 0.37-1.33, P = .0006) than sorafenib group. Hand-foot skin reaction, diarrhea, fatigue, vomiting, and alanine aminotransferase (ALT) elevation were common adverse events. The adverse events were similar between the 2 groups excluding elevated ALT.

CONCLUSION

Although the TACE + sorafenib group had a higher elevated ALT, the combination of TACE + sorafenib had an OS benefit compared with sorafenib in the treatment of intermediate-advanced HCC. Further research is necessary to affirm this finding and clarify whether certain subgroups benefit from different combinations between TACE and sorafenib.

The Role of Non-Coding RNAs in the Sorafenib Resistance of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related death. Sorafenib is approved by the U.S. Food and Drug Administration to be a first-line chemotherapy agent for patients with advanced HCC. A portion of advanced HCC patients can benefit from the treatment with sorafenib, but many patients ultimately develop sorafenib resistance, leading to a poor prognosis. The molecular mechanisms of sorafenib resistance are sophisticated and indefinite. Notably, non-coding RNAs (ncRNAs), which include long ncRNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs), are critically participated in the occurrence and progression of tumors. Moreover, growing evidence has suggested that ncRNAs are crucial regulators in the development of resistance to sorafenib. Herein, we integrally and systematically summarized the molecular mechanisms and vital role of ncRNAs impact sorafenib resistance of HCC, and ultimately explored the potential clinical administrations of ncRNAs as new prognostic biomarkers and therapeutic targets for HCC.

Insights into an Immunotherapeutic Approach to Combat Multidrug Resistance in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) has emerged as one of the most lethal cancers worldwide because of its high refractoriness and multi-drug resistance to existing chemotherapies, which leads to poor patient survival. Novel pharmacological strategies to tackle HCC are based on oral multi-kinase inhibitors like sorafenib; however, the clinical use of the drug is restricted due to the limited survival rate and significant side effects, suggesting the existence of a primary or/and acquired drug-resistance mechanism. Because of this hurdle, HCC patients are forced through incomplete therapy. Although multiple approaches have been employed in parallel to overcome multidrug resistance (MDR), the results are varying with insignificant outcomes. In the past decade, cancer immunotherapy has emerged as a breakthrough approach and has played a critical role in HCC treatment. The liver is the main immune organ of the lymphatic system. Researchers utilize immunotherapy because immune evasion is considered a major reason for rapid HCC progression. Moreover, the immune response can be augmented and sustained, thus preventing cancer relapse over the post-treatment period. In this review, we provide detailed insights into the immunotherapeutic approaches to combat MDR by focusing on HCC, together with challenges in clinical translation.

miR-497 inhibits proliferation and invasion in triple-negative breast cancer cells via YAP1

MicroRNA (miR)-497 has been reported as a tumor suppressor in various cancer types. Nonetheless, the regulation of triple-negative breast cancer (TNBC) by miR-497 remains poorly understood. The present study aimed to investigate the potential function and mechanism of miR-497 in TNBC. A total of 36 TNBC and matched non-cancerous tissue samples were collected for analysis. Reverse transcription-quantitative PCR was performed to detect the miR-497 levels in TNBC tissue. The association between miR-497 expression, clinical characteristics and survival was then analyzed. To investigate the role of miR-497 in TNBC, MTT, colony formation, Transwell invasion, cell cycle and cell apoptosis assays were conducted following transfection of miR-497 mimics into the MDA-MB-231 and MDA-MB-468 cell lines. Luciferase reporter assays and western blot analysis were used to confirm the regulation of a putative target of miR-497. The results indicated that the expression of miR-497 was downregulated in the TNBC specimens. Further analysis demonstrated that the expression of miR-497 was downregulated in patients with advanced TNBC stages and that low miR-497 was associated with poor prognosis in patients with TNBC. Transfection of miR-497 mimics inhibited TNBC cell proliferation and increased cell apoptosis in MDA-MB-231 and MDA-MB-468 cells. Moreover, cell migration was inhibited following overexpression of miR-497, which also led to the arrest of the breast cancer cells in the G₀/G₁ phase of the cell cycle. Yes-associated protein 1 (YAP1), a critical molecule in the Hippo pathway, was identified as a target of miR-497. Notably, the protein and mRNA expression levels of YAP1 in MDA-MB-231 and MDA-MB-468 cells were downregulated following overexpression of miR-497. Overall, the findings of the present study indicated that miR-497 inhibited TNBC cell proliferation and migration and induced cell apoptosis by negatively regulating YAP1 expression. Thus, targeting miR-497 may represent a potential strategy for the treatment of TNBC.

Identification of novel targets of miR-622 in hepatocellular carcinoma reveals common regulation of cooperating genes and outlines the oncogenic role of zinc finger CCHC-type containing 11

The poor prognosis of advanced hepatocellular carcinoma (HCC) is driven by diverse features including dysregulated microRNAs inducing drug resistance and stemness. Lin-28 homolog A (LIN28A) and its partner zinc finger CCHC-type containing 11 (ZCCHC11) cooperate in binding, oligouridylation and subsequent degradation of tumorsuppressive let-7 precursor microRNAs. Functionally, activation of LIN28A was recently shown to promote stemness and chemoresistance in HCC. However, the expression and regulation of LIN28A in HCC had been unclear. Moreover, the expression, regulation and function of ZCCHC11 in liver cancer remained elusive. In contrast to "one-microRNA-one-target" interactions, we identified common binding sites for miR-622 in both LIN28A and ZCCHC11, suggesting miR-622 to function as a superior pathway regulator. Applying comprehensive microRNA database screening, human hepatocytes and HCC cell lines, patient-derived tissue samples as well as "The Cancer Genome Atlas" (TCGA) patient cohorts, we demonstrated that loss of tumorsuppressive miR-622 mediates derepression and overexpression of LIN28A in HCC. Moreover, the cooperator of LIN28A, ZCCHC11, was newly identified as a prognostic and therapeutic target of miR-622 in liver cancer. Together, identification of novel miR-622 target genes revealed common regulation of cooperating genes and outlines the previously unknown oncogenic role of ZCCHC11 in liver cancer.

Autophagy, an accomplice or antagonist of drug resistance in HCC?

Hepatocellular carcinoma (HCC) is a highly lethal malignancy characterized by poor prognosis and a low 5-year survival rate. Drug treatment is proving to be effective in anti-HCC. However, only a small number of HCC patients exhibit sensitive responses, and drug resistance occurs frequently in advanced patients. Autophagy, an evolutionary process responsible for the degradation of cellular substances, is closely associated with the acquisition and maintenance of drug resistance for HCC. This review focuses on autophagic proteins and explores the intricate relationship between autophagy and cancer stem cells, tumor-derived exosomes, and noncoding RNA. Clinical trials involved in autophagy inhibition combined with anticancer drugs are also concerned.

miR-126-3p contributes to sorafenib resistance in hepatocellular carcinoma via downregulating SPRED1

Background

Sorafenib can prolong the survival of patients with advanced hepatocellular carcinoma (HCC). However, drug resistance remains the main obstacle to improving its efficiency. This study aimed to explore the likely molecular mechanism of sorafenib resistance.

Methods

Differentially expressed microRNAs (miRNAs) related to sorafenib response were analyzed with the Limma package in R software. The expression levels of miR-126-3p and sprouty-related EVH1 domain-containing protein 1 (SPRED1) in HCC cells were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell viability and proliferation were detected with Cell Counting Kit-8 (CCK-8), EdU proliferation, and clone formation assays. Transwell assays were performed to measure cell migration and invasion. TargetScan, MicroRNA Target Prediction Database (miRDB), and StarBase v2.0 were used to predict the targets of miR-126-3p. SPRED1 was confirmed as a target gene of miR-126-3p by dual-luciferase reporter assay and Western blotting. Finally, the in vivo anti-tumor effect of LV-miR-126-3p inhibitor combined with sorafenib was evaluated via subcutaneous tumor models.

Results

HCC cells with high expression of miR-126-3p exhibited increased resistance to sorafenib. The results of bioinformatics analysis and the dual-luciferase reporter assay showed that miR-126-3p directly targeted SPRED1. The sensitivity of HCC cells to sorafenib was markedly enhanced by SPRED1 upregulation. Gain- and loss-of function experiments verified that miR-126-3p induced sorafenib resistance in HCC through downregulating SPRED1. Furthermore, the inhibition of miR-126-3p markedly increased the effectiveness of sorafenib against HCC in vivo. Mechanistically, our results suggested that miR-126-3p promoted sorafenib resistance via targeting SPRED1 and activating the ERK signaling pathway.

Conclusions

Our study demonstrates that regulating the miR-126-3p/SPRED1 axis might be a promising strategy for enhancing the antitumor effect of sorafenib in the treatment of HCC.

Circ_0001175 Promotes Hepatocellular Carcinoma Cell Proliferation and Metastasis by Regulating miR-130a-5p

Objective

Many aberrantly expressed circular RNAs (circRNAs) play important roles in the development and progression of hepatocellular carcinoma (HCC). However, the exact function of circ_0001175 in HCC cells is unknown. Our study aimed to investigate the expression characteristics of circ_0001175 in HCC and its effects on the proliferation, migration and invasion of HCC cells, and to explore the potential mechanism.

Materials and Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were carried out to detect circ_0001175, microRNA-130a-5p (miR-130a-5p) and sorting nexin 5 (SNX5) expressions in HCC tissues and cells; cell counting kit-8 (CCK-8), BrdU and Transwell assays were conducted to detect the proliferation, migration and invasion of HCC cells. A lung metastasis model in nude mice was used to examine the effect of circ_0001175 on the metastasis of HCC cells in vivo. Bioinformatics prediction, luciferase reporter gene experiment, Ago2-RIP experiment and RNA pull-down assay were adopted to identify the binding relationships among circ_0001175, miR-130a-5p and SNX5.

Results

Circ_0001175 and SNX5 expressions were up-regulated in HCC tissues and cell lines, while miR-130a-5p expression was down-regulated. Abnormal expressions of circ_0001175, miR-130a-5p and SNX5 were associated with poor clinicopathological features of HCC patients; circ_0001175 facilitated HCC cell proliferation, migration and invasion in vitro and promoted lung metastasis in vivo; miR-130a-5p inhibited the above malignant biological behaviors of HCC cells, and it could reverse the function of circ_0001175. SNX5 was identified as a target gene of miR-130a-5p, and circ_0001175 could sponge miR-130a-5p and up-regulate the expression of SNX5 in HCC cells.

Conclusion

Circ_0001175 is highly expressed in HCC and facilitates HCC progression through regulating miR-130a-5p/SNX5 axis.

An aberrant DNA methylation signature for predicting hepatocellular carcinoma

Background

By the time they are clinically diagnosed, patients with hepatocellular carcinoma (HCC) are often at the advanced stage. DNA methylation has become a useful predictor of prognosis for cancer patients. Research on DNA methylation as a biomarker for assessing the risk of occurrence in HCC patients is limited. The purpose of this study was to develop an efficient methylation site model for predicting survival in patients with HCC.

Methods

DNA methylation and gene expression profile data were extracted from The Cancer Genome Atlas (TCGA) database. Markers of DNA-methylated site in two subsets (the training subset and the test subset) were identified using a random survival forest algorithm and Cox proportional hazards regression. Then, Gene Ontology annotations were applied to investigate the functions of DNA methylation signatures.

Results

A total of 37 hub genes containing 713 methylated sites were identified among the differentially methylated genes (DMGs) and differentially expressed genes (DEGs). Finally, seven methylation sites (cg12824782, cg24871714, cg18683774, cg22796509, cg19450025, cg10474350, and cg06511917) were identified. In the training group and the test group, the area under the curve predicting the survival of patients with HCC was 0.750 and 0.742, respectively. The seven methylation sites signature could be used to divide the patients in the training group into high- and low-risk subgroups [overall survival (OS): 2.81 vs. 2.11 years; log-rank test, P<0.05]. Then, the prediction ability of the model was validated in the test dataset through risk stratification (OS: 2.04 vs. 2.88 years; log-rank test, P<0.05). Functional analysis demonstrated that these signature genes were related to the activity of DNA-binding transcription activator, RNA polymerase II distal enhancer sequence-specific DNA binding, and enhancer sequence-specific DNA binding.

Conclusions

The results of this study showed that the signature is useful for predicting the survival of HCC patients and thus, can facilitate treatment-related decision-making.

miR-876 Inhibits EMT and Liver Fibrosis via POSTN to Suppress Metastasis in Hepatocellular Carcinoma

Background

The asymptomatic onset, frequent recurrence, and poor prognosis of hepatocellular carcinoma (HCC) prompted us to identify new therapeutic targets or predictive markers of HCC diagnosis or prognosis.

Methods

In this study, bioinformatics analysis was used to screen for target miRNAs from the open-access TCGA database. Transwell assays, Western blotting, and qRT-PCR analyses were used to detect cellular functions and gene expression in HCC cells and samples. A nude mouse tumorigenesis model was established to facilitate the observation of HCC progression. Other assays included luciferase reporter assays, IHC, and survival analysis.

Results

We found that the identified miR-876 from TCGA was expressed at low levels in HCC cell lines and that low miR-876 expression was corrected with liver cirrhosis, tumor thrombus, and TNM stage. Further research revealed that miR-876 regulated cell invasion, EMT, and collagen expression by targeting POSTN expression. miR-876 and POSTN were inversely correlated in HCC samples and associated with EMT status and liver fibrosis in clinical HCC tissues. miR-876 inhibited the liver cancer progression in in vivo animal assays. Finally, both miR-876 and POSTN were risk factors for HCC survival, and HCC patients with combined low miR-876 and high POSTN expression had worse prognosis.

Conclusions

miR-876 inhibited HCC EMT and fibrosis by targeting POSTN, thus affecting HCC progression and prognosis. miR-876 and POSTN may be useful therapeutic targets or prognostic markers of HCC.

miR-133a-3p Regulates Hepatocellular Carcinoma Progression Through Targeting CORO1C

Introduction

MicroRNAs (miRNAs) are key modulators for gene expression via inducing translational repression or target gene degradation. miR-133a-3p was reported to stimulate or inhibit cancer progression but its role in hepatocellular carcinoma (HCC) remains to be explored.

Methods

Quantitative real-time PCR (RT-qPCR) was utilized to explore miR-133a-3p expression level in HCC cells. Dual-luciferase activity reporter assay was used to validate the direct interaction between miR-133a-3p and coronin-like actin-binding protein 1C (CORO1C). In addition, we analyzed the expression levels of miR-133a-3p and CORO1C in HCC tissues and normal tissues on the UCALAN website. Functional assays including cell counting kit-8 assay, colony formation assay, flow cytometry analysis and transwell invasion assay were conducted to explore the biological functions of miR-133a-3p in HCC.

Results

miR-133a-3p was found to have downregulated expression in HCC tissues and cells. Meanwhile, we showed that low miR-133a-3p levels were correlated with poorer overall survival of HCC patients. Overexpression of miR-133a-3p suppressed HCC cell growth and invasion but promoted cell apoptosis via targeting CORO1C.

Discussion

Our results revealed a novel mechanism of miR-133a-3p in regulating HCC progression and provided evidence that miR-133a-3p functions as a tumor suppressor in HCC.

Long non‑coding RNA MKLN1‑AS aggravates hepatocellular carcinoma progression by functioning as a molecular sponge for miR‑654‑3p, thereby promoting hepatoma‑derived growth factor expression

Long non‑coding RNAs (lncRNAs) have recently gained attention due to their important roles in human cancer types, such as breast and gastric cancer. The present study measured alterations in muskelin 1 antisense RNA (MKLN1‑AS) expression in hepatocellular carcinoma (HCC) and evaluated its clinical value in patients with HCC. Additionally, the current study investigated the effects of MKLN1‑AS on the malignant features of HCC cells. The detailed molecular mechanisms underlying the cancer‑promoting activities of MKLN1‑AS in HCC cells were also elucidated. MKLN1‑AS expression in HCC tissues and cell lines was detected using reverse‑transcription quantitative PCR (RT‑qPCR). Cell Counting Kit‑8 assays and flow cytometry were used to determine the roles of MKLN1‑AS in HCC cell proliferation and apoptosis. Migration and invasion assays, as well as tumor xenograft experiments were conducted to analyze migration and invasion in vitro and tumor growth in vivo, respectively. The interaction among microRNA‑654‑3p (miR‑654‑3p), MKLN1‑AS and hepatoma‑derived growth factor (HDGF) in HCC was investigated using luciferase reporter assay, RNA immunoprecipitation assay, RT‑qPCR, western blotting and rescue experiments. MKLN1‑AS was upregulated in HCC tissues and cell lines, and a high MKLN1‑AS expression was associated with shorter overall survival and disease‑free survival in patients with HCC. Functionally, the knockdown of MKLN1‑AS impaired HCC cell proliferation, migration and invasion, as well as induced cell apoptosis in vitro. Knockdown of MKLN1‑AS expression also inhibited cell proliferation in vivo. The results indicated that MKLN1‑AS functioned as a competing endogenous RNA by sponging miR‑654‑3p in HCC cells. Additionally, miR‑654‑3p targeting of HDGF was positively modulated by MKLN1‑AS, and miR‑654‑3p knockdown partially abrogated this effect. Rescue experiments demonstrated that knockdown of miR‑654‑3p and overexpression of HDGF both abolished MKLN1‑AS knockdown‑induced cellular processes in HCC. In summary, MKLN1‑AS induced pro‑oncogenic effects during HCC progression by serving as a molecular sponge for miR‑654‑3p to increase HDGF expression. Therefore, the MKLN1‑AS/miR‑654‑3p/HDGF axis may offer a novel target for the diagnosis, prognosis, prevention and treatment of HCC.

The Role of the Liver-Specific microRNA, miRNA-122 in the HCV Replication Cycle

Hepatitis C virus (HCV) replication requires annealing of a liver specific microRNA, miR-122 to 2 sites on 5' untranslated region (UTR). While, microRNAs downregulate gene expression by binding to the 3' untranslated region of the target mRNA, in this case, the microRNA anneals to the 5'UTR of the viral genomes and upregulates the viral lifecycle. In this review, we explore the current understandings of the mechanisms by which miR-122 promotes the HCV lifecycle, and its contributions to pathogenesis. Annealing of miR-122 has been reported to (a) stimulate virus translation by promoting the formation of translationally active internal ribosome entry site (IRES) RNA structure, (b) stabilize the genome, and (c) induce viral genomic RNA replication. MiR-122 modulates lipid metabolism and suppresses tumor formation, and sequestration by HCV may influence virus pathogenesis. We also discuss the possible use of miR-122 as a biomarker for chronic hepatitis and as a therapeutic target. Finally, we discuss roles for miR-122 and other microRNAs in promoting other viruses.

Clinical significance and functional role of transmembrane protein 47 (TMEM47) in chemoresistance of hepatocellular carcinoma

Chemoresistance is the main cause of chemotherapy failure in patients with hepatocellular carcinoma (HCC). The gene encoding transmembrane protein 47 (TMEM47) was previously identified to be significantly upregulated in HCC cell lines with acquired chemoresistance. The aim of the present study was to characterize the clinical significance and function of TMEM47 in HCC chemoresistance. The results demonstrated that the TMEM47 expression levels in the tumors of patients not responding to cisplatin-based transarterial chemoembolization (TACE) treatment was significantly higher compared with those in patients who responded to TACE treatment. Moreover, analyses from clinical samples and HCC cell lines indicated that TMEM47 expression may be upregulated in HCC in response to cisplatin treatment. Furthermore, the TMEM47 mRNA expression levels were positively correlated with the degree of cisplatin resistance of HCC cells. Overexpression of TMEM47 in HCC cells significantly promoted cisplatin resistance. The present study also demonstrated that targeted inhibition of TMEM47 could significantly reduce cisplatin resistance of cisplatin-resistant HCC cells via enhancing caspase-mediated apoptosis. In addition, targeted inhibition of TMEM47 enhanced the sensitivity of cisplatin-resistant cells to cisplatin via suppressing cisplatin-induced activation of the genes involved in drug efflux and metabolism. The present study also validated that TMEM47 expression was significantly correlated with multi-drug resistance-associated protein 1 in patients with HCC who received TACE treatment. In conclusion, the findings of the present study demonstrated that TMEM47 may be a useful biomarker for predicting the response to chemotherapy and a potential therapeutic target for overcoming HCC chemoresistance.

The Prognosis of Hepatocellular Carcinoma Treated with Sorafenib in Combination with TACE

OBJECTIVE

Sorafenib have been shown to be effective in the treatment of advanced HCC and has been standard therapy since its release in Japan in 2009 (Llovet et al., 2008; Cheng et al., 2009). However, due to a low response rate, more aggressive combination treatment has been utilized as a multimodal strategy. The present study aimed to determine the efficacy of sorafenib alone and in combination with transarterial chemoembolization (TACE) for the treatment of advanced HCC.

METHODS

All patients with unresectable advanced HCC who were prescribed sorafenib at Kanto Rosai Hospital were included in the study. Five-year overall survival (OS) rates were estimated for patients treated with sorafenib alone or in combination with TACE. Multivariate and univariate regression analyses were performed to identify factors affecting OS. Analysis using propensity score matching and inverse-probability weights were also performed.

RESULTS

A total of 46 patients were treated with sorafenib up to June 2018. The total sorafenib dose administered was higher in the TACE combination group (70900 mg vs. 24000 mg vs. with sorafenib alone), although the relative dose intensity was lower (11.7% vs. 17.6%, respectively). The 5-year survival prognosis estimated using the Kaplan-Meier method was longer in patients treated with sorafenib in combination with TACE versus sorafenib alone (36.3% vs. 7.7%). Combination with TACE was the only factor associated with improved OS in both univariate and multivariate analysis. Among cases matched by propensity scores the hazard rate for combination with TACE was 0.067 (95% CI 0.091-1.128).

CONCLUSION

With an array of therapeutic options currently available, it is important to determine the efficacy of different multimodal strategies, such as sorafenib combined TACE, for patients with unresectable HCC.

Porphyromonas gingivalis Promotes the Proliferation and Migration of Esophageal Squamous Cell Carcinoma through the miR-194/GRHL3/PTEN/Akt Axis

Recent studies have revealed that Porphyromonas gingivalis is closely related to the occurrence and progression of esophageal squamous cell carcinoma (ESCC). However, the underlying mechanism of P. gingivalis in ESCC has not been well elucidated. To explore the mechanism of P. gingivalis infection in ESCC, cellular proliferation, invasion, and migration models of KYSE-30 and KYSE-150 cells infected by P. gingivalis at a multiplicity of infection (MOI) of 10 were established. The results showed that P. gingivalis infection could drastically increase the proliferation, invasion, and migration ability of ESCC. Furthermore, the results of high-throughput sequencing showed that miR-194 was considerably upregulated in infected cells compared with control cells, which was further verified by qRT-PCR. The inhibition or overexpression of miR-194 had a significant effect on KYSE-30 and KYSE-150 cell migration and invasion. Additionally, the levels of GRHL3 and PTEN were decreased in P. gingivalis-infected esophageal cancer cells compared with uninfected esophageal cancer cells. Furthermore, dual-luciferase experiments confirmed that GRHL3 is a direct target of miR-194. In addition, the GRHL3-related pathway was investigated, and the levels of GRHL3 and PTEN were downregulated while the level of p-Akt was upregulated after P. gingivalis infection. Taken together, these findings indicated that P. gingivalis might promote ESCC proliferation and migration via the miR-194/GRHL3/PTEN/Akt signaling axis.

The Crosstalk between Tumor Cells and the Microenvironment in Hepatocellular Carcinoma: The Role of Exosomal microRNAs and their Clinical Implications

The communication between hepatocellular carcinoma (HCC) cells and their microenvironment is an essential mechanism supporting or preventing tumor development and progression. Recent evidence has identified extracellular vesicles (EVs) as one of the mechanisms mediating paracrine signaling between cells. Exosomes, the most described class of EVs, deliver proteins, mRNAs, noncoding RNAs, DNA, and lipids to recipient cells, also at remote distances. MicroRNAs (miRNAs), as part of the non-coding RNA exosomal cargo, have an important role in regulating cellular pathways in targeted cells, regulating several processes related to tumor progression invasion and metastasis, such as angiogenesis, immune-escape, epithelial-to-mesenchymal transition, invasion, and multi-drug resistance. Accumulating evidence suggests exosomal miRNAs as relevant players in the dynamic crosstalk among cancerous, immune, and stromal cells in establishing the tumorigenic microenvironment. In addition, they sustain the metastasic niche formation at distant sites. In this review, we summarized the recent findings on the role of the exosome-derived miRNAs in the cross-communication between tumor cells and different hepatic resident cells, with a focus on the molecular mechanisms responsible for the cell re-programming. In addition, we describe the clinical implication derived from the exosomal miRNA-driven immunomodulation to the current immunotherapy strategies and the molecular aspects influencing the resistance to therapeutic agents.