Maintenance of stemness by miR-589-5p in hepatocellular carcinoma cells promotes chemoresistance via STAT3 signaling

Epigenetic regulation of hepatocellular carcinoma progression: MicroRNAs as therapeutic, diagnostic and prognostic factors

Hepatocellular carcinoma (HCC), a significant challenge for public healthcare systems in developed Western countries including the USA, Canada, and the UK, is influenced by different risk factors including hepatitis virus infections, alcoholism, and smoking. The disruption in the balance of microRNAs (miRNAs) plays a vital function in tumorigenesis, given their function as regulators in numerous signaling networks. These miRNAs, which are mature and active in the cytoplasm, work by reducing the expression of target genes through their impact on mRNAs. MiRNAs are particularly significant in HCC as they regulate key aspects of the tumor, like proliferation and invasion. Additionally, during treatment phases such as chemotherapy and radiotherapy, the levels of miRNAs are key determinants. Pre-clinical experiments have demonstrated that altered miRNA expression contributes to HCC development, metastasis, drug resistance, and radio-resistance, highlighting related molecular pathways and processes like MMPs, EMT, apoptosis, and autophagy. Furthermore, the regulatory role of miRNAs in HCC extends beyond their immediate function, as they are also influenced by other epigenetic factors like lncRNAs and circular RNAs (circRNAs), as discussed in recent reviews. Applying these discoveries in predicting the prognosis of HCC could mark a significant advancement in the therapy of this disease.

Silencing lncRNA-DARS-AS1 suppresses nonsmall cell lung cancer progression by stimulating miR-302a-3p to inhibit ACAT1 expression

Long noncoding RNAs (LncRNAs) have been gaining attention as potential therapeutic targets for lung cancer. In this study, we investigated the expression and biological behavior of lncRNA DARS-AS1, its predicted interacting partner miR-302a-3p, and ACAT1 in nonsmall cell lung cancer (NSCLC). The transcript level of DARS-AS1, miR-302a-3p, and ACAT1 was analyzed using qRT-PCR. Endogenous expression of ACAT1 and the expression of-and changes in-AKT/ERK pathway-related proteins were determined using western blotting. MTS, Transwell, and apoptosis experiments were used to investigate the behavior of cells. The subcellular localization of DARS-AS1 was verified using FISH, and its binding site was verified using dual-luciferase reporter experiments. The binding of DARS-AS1 to miR-302a-3p was verified using RNA co-immunoprecipitation. In vivo experiments were performed using a xenograft model to determine the effect of DARS-AS1 knockout on ACAT1 and NSCLC. lncRNA DARS-AS1 was upregulated in NSCLC cell lines and tissues and the expression of lncRNA DARS-AS1 was negatively correlated with survival of patients with NSCLC. Knockdown of DARS-AS1 inhibited the malignant behaviors of NSCLC via upregulating miR-302a-3p. miR-302a-3p induced suppression of malignancy through regulating oncogene ACAT1. This study demonstrates that the DARS-AS1-miR-302a-3p-ACAT1 pathway plays a key role in NSCLC.

Hijacking and rewiring of host CircRNA/miRNA/mRNA competitive endogenous RNA (ceRNA) regulatory networks by oncoviruses during development of viral cancers

A significant portion of human cancers are caused by oncoviruses (12%-25%). Oncoviruses employ various strategies to promote their replication and induce tumourigenesis in host cells, one of which involves modifying the gene expression patterns of the host cells, leading to the rewiring of genes and resulting in significant changes in cellular processes and signalling pathways. In recent studies, a specific mode of gene regulation known as circular RNA (circRNA)-mediated competing endogenous RNA (ceRNA) networks has emerged as a key player in this context. CircRNAs, a class of non-coding RNA molecules, can interact with other RNA molecules, such as mRNAs and microRNAs (miRNAs), through a process known as ceRNA crosstalk. This interaction occurs when circRNAs, acting as sponges, sequester miRNAs, thereby preventing them from binding to their target mRNAs and modulating their expression. By rewiring the host cell genome, oncoviruses have the ability to manipulate the expression and activity of circRNAs, thereby influencing the ceRNA networks that can profoundly impact cellular processes such as cell proliferation, differentiation, apoptosis, and immune responses. This review focuses on a comprehensive evaluation of the latest findings on the involvement of virus-induced reprogramming of host circRNA-mediated ceRNA networks in the development and pathophysiology of human viral cancers, including cervical cancer, gastric cancer, nasopharyngeal carcinoma, Kaposi's sarcoma, hepatocellular carcinoma, and diffuse large B cell lymphoma. Understanding these mechanisms can improve our knowledge of how oncoviruses contribute to human tumourigenesis and identify potential targets for developing optimised therapies and diagnostic tools for viral cancers.

miRNAs as short non-coding RNAs in regulating doxorubicin resistance

The treatment of cancer patients has been prohibited by chemoresistance. Doxorubicin (DOX) is an anti-tumor compound disrupting proliferation and triggering cell cycle arrest via inhibiting activity of topoisomerase I and II. miRNAs are endogenous RNAs localized in cytoplasm to reduce gene level. Abnormal expression of miRNAs changes DOX cytotoxicity. Overexpression of tumor-promoting miRNAs induces DOX resistance, while tumor-suppressor miRNAs inhibit DOX resistance. The miRNA-mediated regulation of cell death and hallmarks of cancer can affect response to DOX chemotherapy in tumor cells. The transporters such as P-glycoprotein are regulated by miRNAs in DOX chemotherapy. Upstream mediators including lncRNAs and circRNAs target miRNAs in affecting capacity of DOX. The response to DOX chemotherapy can be facilitated after administration of agents that are mostly phytochemicals including curcumol, honokiol and ursolic acid. These agents can regulate miRNA expression increasing DOX's cytotoxicity. Since delivery of DOX alone or in combination with other drugs and genes can cause synergistic impact, the nanoparticles have been introduced for drug sensitivity. The non-coding RNAs determine the response of tumor cells to doxorubicin chemotherapy. microRNAs play a key role in this case and they can be sponged by lncRNAs and circRNAs, showing interaction among non-coding RNAs in the regulation of doxorubicin sensitivity.

Noncoding RNAs as regulators of STAT3 pathway in gastrointestinal cancers: Roles in cancer progression and therapeutic response

Gastrointestinal (GI) tumors (cancers of the esophagus, gastric, liver, pancreas, colon, and rectum) contribute to a large number of deaths worldwide. STAT3 is an oncogenic transcription factor that promotes the transcription of genes associated with proliferation, antiapoptosis, survival, and metastasis. STAT3 is overactivated in many human malignancies including GI tumors which accelerates tumor progression, metastasis, and drug resistance. Research in recent years demonstrated that noncoding RNAs (ncRNAs) play a major role in the regulation of many signaling pathways including the STAT3 pathway. The major types of endogenous ncRNAs that are being extensively studied in oncology are microRNAs, long noncoding RNAs, and circular RNAs. These ncRNAs can either be tumor-promoters or tumor-suppressors and each one of them imparts their activity via different mechanisms. The STAT3 pathway is also tightly modulated by ncRNAs. In this article, we have elaborated on the tumor-promoting role of STAT3 signaling in GI tumors. Subsequently, we have comprehensively discussed the oncogenic as well as tumor suppressor functions and mechanism of action of ncRNAs that are known to modulate STAT3 signaling in GI cancers.

Identification of PTPN20 as an innate immunity-related gene in gastric cancer with Helicobacter pylori infection

Background

Gastric cancer (GC) is among the deadliest diseases with countless incidences and deaths each year. Helicobacter pylori (Hp) is the primary type of microbe that colonizes the stomach. In recent years, increasing evidence has demonstrated that Hp infection is one of the main risk factors for GC. Elucidating the molecular mechanism of how Hp leads to GC will not only benefit the treatment of GC, but also boost the development of therapeutics for other gastric disorders caused by Hp infection. In this study, we aimed to identify innate immunity-related genes in GC and investigate their potentials as prognostic markers and therapeutic targets for Hp-related GC.

Methods

Firstly, we analyzed the differentially expressed innate immunity-related genes in GC samples from the TCGA database. Then prognostic correlation analysis was carried out to explore the prognostic value of these candidate genes. By combing transcriptome data, somatic mutation data, and clinical data, co-expression analysis, functional enrichment analysis, tumor mutational burden analysis, and immune infiltration analysis were performed to reveal the pathological relevance of the candidate gene. Finally, ceRNA network was constructed to identify the genes and pathways for the regulation of the candidate gene.

Results

We revealed that protein tyrosine phosphatase non-receptor type 20 (PTPN20) is a significant prognostic marker in Hp-related GC. Thus, PTPN20 levels have the potential to efficiently predict the survival of Hp-related GC patients. In addition, PTPN20 is associated with immune cell infiltration and tumor mutation burden in these GC patients. Moreover, we have also identified PTPN20-related genes, PTPN20 protein-protein interactions, and the PTPN20 ceRNA network.

Conclusion

Our data suggest that PTPN20 may have critical functions in Hp-related GC. Targeting PTPN20 may be a promising way to treat Hp-related GC.

METTL3 and STAT3 form a positive feedback loop to promote cell metastasis in hepatocellular carcinoma

BACKGROUND

It is well-established that most Hepatocellular carcinoma (HCC) patients die of metastasis, yet the potential mechanisms orchestrating metastasis remain poorly understood. Current evidence suggests that the dysregulation of METTL3-mediated m6A methylation modification is closely associated with cancer progression. STAT3 is an oncogenic transcription factor that reportedly plays a central role in the occurrence and development of HCC. However, the relationship between METTL3 and STAT3 in HCC metastasis remains unclear.

METHODS

The relationship between METTL3 expression and the survival of HCC patients was assessed by online tools GEPIA and Kaplan-Meier Plotter. Western blotting, Tissue microarray (TMA), and immunohistochemistry (IHC) staining were used to evaluate the expression levels of METTL3 and STAT3 in HCC cell lines and metastatic and non-metastatic tissues. Methylated RNA immunoprecipitation (MeRIP), MeRIP sequencing (MeRIP-seq), qRT-PCR, RNA immunoprecipitation (RIP), Western blotting and luciferase reporter gene assay were utilized to clarify the mechanism of METTL3 regulating STAT3 expression. Immunofluorescence staining, Western blotting, qRT-PCR, Co-immunoprecipitation (Co-IP), IHC staining, TMA and Chromatin immunoprecipitation (ChIP) assay were performed to explore the mechanism of STAT3 modulating METTL3 localization. Cell viability, wound healing and transwell assay, and orthotopic xenograft model were used to evaluate the role of METTL3-STAT3 feedback loop in the promotion of HCC metastasis in vitro and in vivo.

RESULTS

METTL3 and STAT3 are both abundantly expressed in high-metastatic HCC cells and tissues. Moreover, a positive correlation was found between the expression of STAT3 and METTL3 in HCC tissues. Mechanistically, METTL3 could induce the m6A modification of STAT3 mRNA, and then promote the translation of m6A-contained STAT3 mRNA by interacting with the translation initiation machinery. In contrast, STAT3 promoted nuclear localization of METTL3 via transcriptionally upregulating WTAP, a vital member of the methyltransferase complex, and facilitated the methyltransferase function of METTL3. METTL3 and STAT3 form a positive feedback loop to accelerate HCC metastasis in vitro and in vivo.

CONCLUSIONS

Our findings reveal a novel mechanism of HCC metastasis and uncover the METTL3-STAT3 feedback signaling as a potential target for the anti-metastatic treatment of HCC. Video Abstract.

Deciphering STAT3 signaling potential in hepatocellular carcinoma: tumorigenesis, treatment resistance, and pharmacological significance

Hepatocellular carcinoma (HCC) is considered one of the greatest challenges to human life and is the most common form of liver cancer. Treatment of HCC depends on chemotherapy, radiotherapy, surgery, and immunotherapy, all of which have their own drawbacks, and patients may develop resistance to these therapies due to the aggressive behavior of HCC cells. New and effective therapies for HCC can be developed by targeting molecular signaling pathways. The expression of signal transducer and activator of transcription 3 (STAT3) in human cancer cells changes, and during cancer progression, the expression tends to increase. After induction of STAT3 signaling by growth factors and cytokines, STAT3 is phosphorylated and translocated to the nucleus to regulate cancer progression. The concept of the current review revolves around the expression and phosphorylation status of STAT3 in HCC, and studies show that the expression of STAT3 is high during the progression of HCC. This review addresses the function of STAT3 as an oncogenic factor in HCC, as STAT3 is able to prevent apoptosis and thus promote the progression of HCC. Moreover, STAT3 regulates both survival- and death-inducing autophagy in HCC and promotes cancer metastasis by inducing the epithelial-mesenchymal transition (EMT). In addition, upregulation of STAT3 is associated with the occurrence of chemoresistance and radioresistance in HCC. Specifically, non-protein-coding transcripts regulate STAT3 signaling in HCC, and their inhibition by antitumor agents may affect tumor progression. In this review, all these topics are discussed in detail to provide further insight into the role of STAT3 in tumorigenesis, treatment resistance, and pharmacological regulation of HCC.

Epigenetic programing of cancer stemness by transcription factors-non-coding RNAs interactions

Cancer 'stemness' is fundamental to cancer existence. It defines the ability of cancer cells to indefinitely perpetuate as well as differentiate. Cancer stem cell populations within a growing tumor also help evade the inhibitory effects of chemo- as well as radiation-therapies, in addition to playing an important role in cancer metastases. NF-κB and STAT-3 are representative transcription factors (TFs) that have long been associated with cancer stemness, thus presenting as attractive targets for cancer therapy. The growing interest in non-coding RNAs (ncRNAs) in the recent years has provided further insight into the mechanisms by which TFs influence cancer stem cell characteristics. There is evidence for a direct regulation of TFs by ncRNAs, such as, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) as well as circular RNAs (circRNAs), and vice versa. Additionally, the TF-ncRNAs regulations are often indirect, involving ncRNA-target genes or the sponging of other ncRNA species by individual ncRNAs. The information is rapidly evolving and this review provides a comprehensive review of TF-ncRNAs interactions with implications on cancer stemness and in response to therapies. Such knowledge will help uncover the many levels of tight regulations that control cancer stemness, providing novel opportunities and targets for therapy in the process.

Potential Treatment Strategies for Hepatocellular Carcinoma Cell Sensitization to Sorafenib

Liver cancer is highly malignant, has a low sensitivity to chemotherapy, and is associated with poor patient prognosis. The last 3 years have seen the emergence of promising targeted therapies for the treatment of hepatocellular carcinoma (HCC). For over 10 years, before the discovery of lenvatinib, sorafenib was only first-line therapeutic agent available for the treatment of advanced HCC. However, several clinical studies have shown that a considerable proportion liver cancer patients are insensitive to sorafenib. Very few patients actually substantially benefit from treatment with sorafenib, and the overall efficacy of the drug has not been satisfactory; therefore, sorafenib has attracted considerable research attention. This study, which is based on previous studies and reports, reviews the potential mechanisms underlying sorafenib resistance and summarizes combination therapies and potential drugs that can be used to sensitize HCC cells to sorafenib.

Loss of 5-hydroxymethylcytosine induces chemotherapy resistance in hepatocellular carcinoma via the 5-hmC/PCAF/AKT axis

Multidrug resistance is a major challenge in treating advanced hepatocellular carcinoma (HCC). Although recent studies have reported that the multidrug resistance phenotype is associated with abnormal DNA methylation in cancer cells, the epigenetic mechanism underlying multidrug resistance remains unknown. Here, we reported that the level of 5-hydroxymethylcytosine (5-hmC) in human HCC tissues was significantly lower than that in adjacent liver tissues, and reduced 5-hmC significantly correlated with malignant phenotypes, including poor differentiation and microvascular invasion; additionally, loss of 5-hmC was related to chemotherapy resistance in post-transplantation HCC patients. Further, the 5-hmC level was regulated by ten-eleven translocation 2 (TET2), and the reduction of TET2 in HCC contributes to chemotherapy resistance through histone acetyltransferase P300/CBP-associated factor (PCAF) inhibition and AKT signaling hyperactivation. In conclusion, loss of 5-hmC induces chemotherapy resistance through PCAF/AKT axis and is a promising chemosensitivity prediction biomarker and therapeutic target for HCC patients.

Knockdown of Circ_0000798 Impedes Cell Growth and Motility of Renal Cell Carcinoma Cells Through Functioning as miRNA Sponge for miR-589-5p

GSE137836 and GSE100186 shows that upregulated hsa_circRNA_0000798 (circ_0000798) is associated with the development and progression of renal cell carcinoma (RCC). However, its biological functions in RCC cells remain unclarified. Here, we planned to explore its action and action of mechanism in RCC cells. Real-time quantitative PCR detected RNA expression and western blotting and immunohistochemistry measured protein expression. In vitro assays, including MTT, EdU, Transwell, and plate colony, scratch wound, apoptosis, and cell cycle assays, and in vivo xenograft tumor model were launched to measure cell dysfunctions. Dual-luciferase reporter assay and RNA pull-down were employed to identify target relationship. Circ_0000798 is upregulated in RCC patients' tumors and cells, and high circ_0000798 is associated with shorter overall survival. RNA interference of circ_0000798 impedes cell metabolic viability and abilities of DNA synthesis, colony formation, wound healing, migration, and invasion in RCC cells but also induces cell cycle arrest and apoptosis. Moreover, circ_0000798 interference could delay tumor growth in vivo. Proliferation markers Ki67 and Bcl-2 were depressed by inhibiting circ_0000798, accompanied with promoted levels of apoptosis proteins Bax and cleaved caspase-3. Of note, circ_0000798 functions as microRNA (miR) sponge for miR-589-5p and thus controls the expression of miR-589-5p-targeting Ras-GTPase-activating protein-binding protein 1 (G3BP1), a newly identified tumor-promoting gene in RCC. Their expressions are linearly correlated with each other in these tumor samples. Circ_0000798 might function oncogenic role in RCC and its downregulation could combat RCC cell growth and motility via targeting miR-589-5p/G3BP1 axis.

Panoramic view of microRNAs in regulating cancer stem cells

Cancer stem cells (CSCs) are a subgroup of tumor cells, possessing the abilities of self-renewal and generation of heterogeneous tumor cell lineages. They are believed to be responsible for tumor initiation, metastasis, as well as chemoresistance in human malignancies. MicroRNAs (miRNAs) are small noncoding RNAs that play essential roles in various cellular activities including CSC initiation and CSC-related properties. Mature miRNAs with ∼22 nucleotides in length are generated from primary miRNAs via its precursors by miRNA-processing machinery. Extensive studies have demonstrated that mature miRNAs modulate CSC initiation and stemness features by regulating multiple pathways and targeting stemness-related factors. Meanwhile, both miRNA precursors and miRNA-processing machinery can also affect CSC properties, unveiling a new insight into miRNA function. The present review summarizes the roles of mature miRNAs, miRNA precursors, and miRNA-processing machinery in regulating CSC properties with a specific focus on the related molecular mechanisms, and also outlines the potential application of miRNAs in cancer diagnosis, predicting prognosis, as well as clinical therapy.

miR-589-5p Inhibits Cell Proliferation by Targeting Histone Deacetylase 3 in Triple Negative Breast Cancer

BACKGROUND

Histone deacetylase 3 (HDAC3) is a potential oncogene that is significantly up-regulated in patients with breast cancer. MicroRNAs (miRs) are a group of small non-coding and regulatory RNAs which have recently been proposed as promising molecules for breast cancer target therapy. In the current study, we investigated the impact of miR-589-5p/ HDAC3 axis on cancer cell development in triple negative breast cancer (TNBC) cells.

METHODS

In-silico analysis determined that miR-589-5p potentially targets HDAC3. We evaluated the HDAC3 and mir-589-5p expression levels in clinical samples and breast cancer cell lines including MDA-MB-231, MDA-MB-468, MCF-7 and MCF-10A. HDAC3 was knocked out to investigate its role on cancer cell progression. Anti-cancerous role of the miR-589-5p was assessed using an expression vector. We evaluated possible alteration in the cell cycle progression, cell viability and cell proliferation, after transient transfection.

RESULTS

HDAC3 was over-expressed in TNBC clinical samples and breast cancer cell lines compared to non-cancerous controls while miR-589-5p was down regulated in cancer cells. Suppression of HDAC3 decreased the cell viability, cell proliferation and colony formation. Similar results were observed after over-expression of the miR-589-5p. Dual-Luciferase reporter assay confirmed the direct targeting of HDAC3 by miR-589-5p.

CONCLUSION

Our results showed that miR-589-5p mediates its anti-proliferative effects on breast cancer cells via targeting HDAC3. These findings suggest that the miR-589-5p/ HDAC3 axis could be considered as a possible therapeutic strategy in TNBC.

miRNAs inspirations in hepatocellular carcinoma: Detrimental and favorable aspects of key performers

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths worldwide. HCC initiation, progression, and therapy failure are all influenced by various variables, including microRNAs (miRNAs). miRNAs are short non-coding RNA sequences that modulate target mRNA expression by deteriorating or repressing translation. miRNAs play an imperative role in HCC pathogenesis by triggering the induction of cancer stem cells (CSCs) and their proliferation, while also delaying apoptosis, sustaining the cell cycle, and inspiring angiogenesis, invasion, and metastasis. Additionally, miRNAs modulate crucial HCC-related molecular pathways such as the p53 pathway, the Wnt/β-catenin pathway, VEGFR2, and PTEN/PI3K/AKT pathway. Consequently, the goal of this review was to give an up-to-date overview of oncogenic and tumor suppressor (TS) miRNAs, as well as their potential significance in HCC pathogenesis and treatment responses, highlighting their underpinning molecular pathways in HCC initiation and progression. Similarly, the biological importance and clinical application of miRNAs in HCC are summarized.

METTL3‐mediated maturation of miR‐589‐5p promotes the malignant development of liver cancer

MiR‐589‐5p could promote liver cancer, but the specific mechanisms are largely unknown. This study examined the role and mechanisms of miR‐589‐5p in liver cancer. The expressions of miR‐589‐5p, METTL3 and m6A in liver cancers were determined by RT‐qPCR. The relationship between miR‐589‐5p and METTL3‐mediated m6A methylation was examined by m6A RNA immunoprecipitation. After transfection, the viability, migration, invasion and expressions of METTL3 and miR‐589‐5p in liver cancer cells were detected by CCK‐8, wound‐healing, transwell and RT‐qPCR. After the xenograft tumour was established in mice, the tumour volume was determined and the expressions of METTL3, miR‐589‐5p, MMP‐2, TIMP‐2, E‐cadherin, N‐cadherin and Vimentin in tumour tissue were detected by RT‐qPCR and Western blotting. In vitro study showed that miR‐589‐5p and METTL3 were highly expressed in liver cancer. METTL3 was positively correlated with miR‐589‐5p. METTL3 up‐regulated the expression of miR‐589‐5p and promoted the maturation of miR‐589‐5p. Overexpressed miR‐589‐5p and METTL3 promoted the viability, migration and invasion of liver cancer cells, while the effects of silencing miR‐589‐5p and METTL3 on the cells were the opposite. The effects of METTL3 overexpression and silencing were reversed by miR‐589‐5p inhibitor and mimic, respectively. In vivo study showed that METLL3 silencing inhibited the growth of xenograft tumour and the expressions of METTL3, MMP‐2, N‐cadherin and Vimentin, promoted the expressions of TIMP‐2 and E‐cadherin, while miR‐589‐5p mimic caused the opposite results and further reversed the effects of METLL3 silencing. In summary, this study found that METTL3‐mediated maturation of miR‐589‐5p promoted the malignant development of liver cancer.

miR-514a-3p: a novel SHP-2 regulatory miRNA that modulates human cytotrophoblast proliferation

Src homology-2 domain-containing protein tyrosine phosphatase 2 (SHP-2), encoded by the PTPN11 gene, forms a central component of multiple signalling pathways and is required for insulin-like growth factor (IGF)-induced placental growth. Altered expression of SHP-2 is associated with aberrant placental and fetal growth indicating that drugs modulating SHP-2 expression may improve adverse pregnancy outcome associated with altered placental growth. We have previously demonstrated that placental PTPN11/SHP-2 expression is controlled by miRNAs. SHP-2 regulatory miRNAs may have therapeutic potential; however, the individual miRNA(s) that regulate SHP-2 expression in the placenta remain to be established. We performed in silico analysis of 3'UTR target prediction databases to identify libraries of Hela cells transfected with individual miRNA mimetics, enriched in potential SHP-2 regulatory miRNAs. Analysis of PTPN11 levels by quantitative (q) PCR revealed that miR-758-3p increased, while miR-514a-3p reduced PTPN11 expression. The expression of miR-514a-3p and miR-758-3p within the human placenta was confirmed by qPCR; miR-514a-3p (but not miR-758-3p) levels inversely correlated with PTPN11 expression. To assess the interaction between these miRNAs and PTPN11/SHP-2, specific mimetics were transfected into first-trimester human placental explants and then cultured for up to 4 days. Overexpression of miR-514a-3p, but not miR-758-3p, significantly reduced PTPN11 and SHP-2 expression. microRNA-ribonucleoprotein complex (miRNP)-associated mRNA assays confirmed that this interaction was direct. miR-514a-3p overexpression attenuated IGF-I-induced trophoblast proliferation (BrdU incorporation). miR-758-3p did not alter trophoblast proliferation. These data demonstrate that by modulating SHP-2 expression, miR-514a-3p is a novel regulator of IGF signalling and proliferation in the human placenta and may have therapeutic potential in pregnancies complicated by altered placental growth.

The role of non-coding RNAs in chemotherapy for gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, hepatic, esophageal, and pancreatic tumors, are responsible for large numbers of deaths around the world. Chemotherapy is the most common approach used to treat advanced GI cancer. However, chemoresistance has emerged as a critical challenge that prevents successful tumor elimination, leading to metastasis and recurrence. Chemoresistance mechanisms are complex, and many factors and pathways are involved. Among these factors, non-coding RNAs (ncRNAs) are critical regulators of GI tumor development and subsequently can induce resistance to chemotherapy. This occurs because ncRNAs can target multiple signaling pathways, affect downstream genes, and modulate proliferation, apoptosis, tumor cell migration, and autophagy. ncRNAs can also induce cancer stem cell features and affect the epithelial-mesenchymal transition. Thus, ncRNAs could possibly act as new targets in chemotherapy combinations to treat GI cancer and to predict treatment response.

MicroRNAs regulating SOX2 in cancer progression and therapy response

The proliferation, metastasis and therapy response of tumour cells are tightly regulated by interaction among various signalling networks. The microRNAs (miRNAs) can bind to 3'-UTR of mRNA and down-regulate expression of target gene. The miRNAs target various molecular pathways in regulating biological events such as apoptosis, differentiation, angiogenesis and migration. The aberrant expression of miRNAs occurs in cancers and they have both tumour-suppressor and tumour-promoting functions. On the contrary, SOX proteins are capable of binding to DNA and regulating gene expression. SOX2 is a well-known member of SOX family that its overexpression in different cancers to ensure progression and stemness. The present review focuses on modulatory impact of miRNAs on SOX2 in affecting growth, migration and therapy response of cancers. The lncRNAs and circRNAs can function as upstream mediators of miRNA/SOX2 axis in cancers. In addition, NF-κB, TNF-α and SOX17 are among other molecular pathways regulating miRNA/SOX2 axis in cancer. Noteworthy, anti-cancer compounds including bufalin and ovatodiolide are suggested to regulate miRNA/SOX2 axis in cancers. The translation of current findings to clinical course can pave the way to effective treatment of cancer patients and improve their prognosis.

Hepatic Cancer Stem Cells: Molecular Mechanisms, Therapeutic Implications, and Circulating Biomarkers

Hepatocellular carcinoma (HCC) is one of the deadliest cancers. HCC is associated with multiple risk factors and is characterized by a marked tumor heterogeneity that makes its molecular classification difficult to apply in the clinics. The lack of circulating biomarkers for the diagnosis, prognosis, and prediction of response to treatments further undermines the possibility of developing personalized therapies. Accumulating evidence affirms the involvement of cancer stem cells (CSCs) in tumor heterogeneity, recurrence, and drug resistance. Owing to the contribution of CSCs to treatment failure, there is an urgent need to develop novel therapeutic strategies targeting, not only the tumor bulk, but also the CSC subpopulation. Clarification of the molecular mechanisms influencing CSC properties, and the identification of their functional roles in tumor progression, may facilitate the discovery of novel CSC-based therapeutic targets to be used alone, or in combination with current anticancer agents, for the treatment of HCC. Here, we review the driving forces behind the regulation of liver CSCs and their therapeutic implications. Additionally, we provide data on their possible exploitation as prognostic and predictive biomarkers in patients with HCC.

The LINC01119-SOCS5 axis as a critical theranostic in triple-negative breast cancer

The development of triple-negative breast cancer (TNBC) is critically regulated by certain tumor-microenvironment-associated cells called mesenchymal stem/stromal cells (MSCs), which we and others have shown promote TNBC progression by activating pro-malignant signaling in neighboring cancer cells. Characterization of these cascades would better our understanding of TNBC biology and bring about therapeutics that eliminate the morbidity and mortality associated with advanced disease. Here, we focused on the emerging class of RNAs called long non-coding RNAs or lncRNAs and utilized a MSC-supported TNBC progression model to identify specific family members of functional relevance to TNBC pathogenesis. Indeed, although some have been described to play functional roles in TNBC, activities of lncRNAs as mediators of tumor-microenvironment-driven TNBC development remain to be fully explored. We report that MSCs stimulate robust expression of LINC01119 in TNBC cells, which in turn induces suppressor of cytokine signaling 5 (SOCS5), leading to accelerated cancer cell growth and tumorigenesis. We show that LINC01119 and SOCS5 exhibit tight correlation across multiple breast cancer gene sets and that they are highly enriched in TNBC patient cohorts. Importantly, we present evidence that the LINC01119-SOCS5 axis represents a powerful prognostic indicator of adverse outcomes in TNBC patients, and demonstrate that its repression severely impairs cancer cell growth. Altogether, our findings identify LINC01119 as a major driver of TNBC development and delineate critical non-coding RNA theranostics of potential translational utility in the management of advanced TNBC, a class of tumors in most need of effective and targeted therapy.

Construction of liver hepatocellular carcinoma-specific lncRNA-miRNA-mRNA network based on bioinformatics analysis

Liver hepatocellular carcinoma (LIHC) is one of the major causes of cancer-related death worldwide with increasing incidences, however there are very few studies about the underlying mechanisms and pathways in the development of LIHC. We obtained LIHC samples from The Cancer Genome Atlas (TCGA) to screen differentially expressed mRNAs, lncRNAs, miRNAs and driver mutations. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, Gene ontology enrichment analyses and protein–protein interaction (PPI) network were performed. Moreover, we constructed a competing endogenous lncRNAs-miRNAs-mRNAs network. Finally, cox proportional hazards regression analysis was used to identify important prognostic differentially expressed genes. Total of 1284 mRNAs, 123 lncRNAs, 47 miRNAs were identified within different tissues of LIHC patients. GO analysis indicated that upregulated and downregulated differentially expressed mRNAs (DEmRNAs) were mainly associated with cell division, DNA replication, mitotic sister chromatid segregation and complement activation respectively. Meanwhile, KEGG terms revealed that upregulated and downregulated DEmRNAs were primarily involved in DNA replication, Metabolic pathways, cell cycle and Metabolic pathways, chemical carcinogenesis, retinol metabolism pathway respectively. Among the DERNAs, 542 lncRNAs-miRNAs-mRNAs pairs were predicted to construct a ceRNA regulatory network including 35 DElncRNAs, 26 DEmiRNAs and 112 DEmRNAs. In the Kaplan‐Meier analysis, total of 43 mRNAs, 14 lncRNAs and 3 miRNAs were screened out to be significantly correlated with overall survival of LIHC. The mutation signatures were analyzed and its correlation with immune infiltrates were evaluated using the TIMER in LIHC. Among the mutation genes, TTN mutation is often associated with poor immune infiltration and a worse prognosis in LIHC. This work conducted a novel lncRNAs-miRNAs-mRNAs network and mutation signatures for finding potential molecular mechanisms underlying the development of LIHC. The biomarkers also can be used for predicting prognosis of LIHC.

The role of miRNAs and lncRNAs in conferring resistance to doxorubicin

Doxorubicin is a chemotherapeutic agent that inhibits topoisomerase II, intercalates within DNA base pairs and results in oxidative DNA damage, thus inducing cell apoptosis. Although it is effective in the treatment of a wide range of human cancers, the emergence of resistance to this drug can increase tumour growth and impact patients' survival. Numerous molecular mechanisms and signalling pathways have been identified that induce resistance to doxorubicin via stimulation of cell proliferation, cell cycle switch and preclusion of apoptosis. A number of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have also been identified that alter sensitivity to doxorubicin. Understanding the particular impact of these non-coding RNAs in conferring resistance to doxorubicin has considerable potential to improve selection of chemotherapeutic regimens for cancer patients. Moreover, modulation of expression of these transcripts is a putative strategy for combating resistance. In the current paper, the influence of miRNAs and lncRNAs in the modification of resistance to doxorubicin is discussed.

Roles of microRNAs in Gastrointestinal Cancer Stem Cell Resistance and Therapeutic Development

Resistance to cancer treatment is one of the major challenges currently faced when treating gastrointestinal (GI) cancers. A major contributing factor to this resistance is the presence of cancer stem cells (CSCs) in GI cancers (e.g., colorectal, pancreatic, gastric, liver cancer). Non-coding RNAs, such as microRNAs (miRNAs), have been found to regulate several key targets that are responsible for cancer stemness, and function as oncogenic miRNAs (oncomiRs) or tumor suppressor miRNAs. As a result, several miRNAs have been found to alter, or be altered by, the expression of CSC-defining markers and their related pathways. These miRNAs can be utilized to affect stemness in multiple ways, including directly targeting CSCs and enhancing the efficacy of cancer therapeutics. This review highlights current studies regarding the roles of miRNAs in GI CSCs, and efforts towards the development of cancer therapeutics.

Long non-coding RNA CCDC183-AS1 acts AS a miR-589-5p sponge to promote the progression of hepatocellular carcinoma through regulating SKP1 expression

Background

Hepatocellular carcinoma (HCC) is a common type of malignant human cancer with high morbidity and poor prognosis, causing numerous deaths per year worldwide. Growing evidence has been demonstrated that long non-coding RNAs (lncRNAs) are closely associated with hepatocarcinogenesis and metastasis. However, the roles, functions, and working mechanisms of most lncRNAs in HCC remain poorly defined.

Methods

Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression level of CCDC183-AS1 in HCC tissues and cell lines. Cell proliferation, migration and invasion ability were evaluated by CCK-8 and transwell assay, respectively. Animal experiments were used to explore the role of CCDC183-AS1 and miR-589-5p in vivo. Bioinformatic analysis, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to confirm the regulatory relationship between CCDC183-AS1, miR-589-5p and SKP1.

Results

Significantly upregulated expression of CCDC183-AS1 was observed in both HCC tissues and cell lines. HCC patients with higher expression of CCDC183-AS1 had a poorer overall survival rate. Functionally, overexpression of CCDC183-AS1 markedly promoted HCC cell proliferation, migration and invasion in vitro and tumor growth and metastasis in vivo, whereas the downregulation of CCDC183-AS1 exerted opposite effects. MiR-589-5p inhibitor counteracted the proliferation, migration and invasion inhibitory effects induced by CCDC183-AS1 silencing. Mechanistically, CCDC183-AS1 acted as a ceRNA through sponging miR-589-5p to offset its inhibitory effect on the target gene SKP1, then promoted the tumorigenesis of HCC.

Conclusions

CCDC183-AS1 functions as an oncogene to promote HCC progression through the CCDC183-AS1/miR-589-5p/SKP1 axis. Our study provided a novel potential therapeutic target for HCC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01861-6.

LINC00680 enhances hepatocellular carcinoma stemness behavior and chemoresistance by sponging miR-568 to upregulate AKT3

BACKGROUND

Hepatocellular carcinoma (HCC) has an extremely poor prognosis due to the development of chemoresistance, coupled with inherently increased stemness properties. Long non-coding RNAs (LncRNAs) are key regulators for tumor cell stemness and chemosensitivity. Currently the relevance between LINC00680 and tumor progression was still largely unknown, with only one study showing its significance in glioblastoma. The study herein was aimed at identifying the role of LINC00680 in the regulation HCC stemness and chemosensitivity.

METHODS

QRT-PCR was used to detect the expression of LINC00680, miR-568 and AKT3 in tissue specimen and cell lines. Gain- or loss-of function assays were applied to access the function of LINC00680 in HCC cells, including cell proliferation and stemness properties. HCC stemness and chemosensitivity were determined by sphere formation, cell viability and colony formation. Luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays were performed to examine the interaction between LINC00680 and miR-568 as well as that between miR-568 and AKT3. A nude mouse xenograft model was established for the in vivo study.

RESULTS

We found that LINC00680 was remarkably upregulated in HCC tissues. Patients with high level of LINC00680 had poorer prognosis. LINC00680 overexpression significantly enhanced HCC cell stemness and decreased in vitro and in vivo chemosensitivity to 5-fluorouracil (5-Fu), whereas LINC00680 knockdown led to opposite results. Mechanism study revealed that LINC00680 regulated HCC stemness and chemosensitivity through sponging miR-568, thereby expediting the expression of AKT3, which further activated its downstream signaling molecules, including mTOR, elF4EBP1, and p70S6K.

CONCLUSION

LINC00680 promotes HCC stemness properties and decreases chemosensitivity through sponging miR-568 to activate AKT3, suggesting that LINC00680 might be a potentially important HCC diagnosis marker and therapeutic target.

Long noncoding RNA HAND2-AS1 reduced the viability of hepatocellular carcinoma via targeting microRNA-300/SOCS5 axis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most prevalent human cancers with high mortality. Long non-coding RNA heart and neural crest derivatives expressed 2 anti-sense 1 (HAND2-AS1) is down-regulated in several cancers including HCC, yet the precise mechanisms how HAND2-AS1 regulates cell survival in HCC remains poorly understood.

METHODS

The expression levels of HAND2-AS1 and miR-300 were measured using quantitative real-time PCR. The protein levels of suppressor of cytokine signaling 5 (SOCS5), Bcl-2, Bax and cleaved caspase-3 were determined by Western blot. Cell viability and cell proliferation were assessed using cell counting kit-8 and clone formation assay, respectively. Cell apoptosis was detected using flow cytometry. The interactions between HAND2-AS1 and miR-300, miR-300 and SOCS5 were validated using luciferase reporter assay.

RESULTS

HAND2-AS1 was down-regulated in HCC tissues and cell lines, and the expression level of HAND2-AS1 was positively correlated to patient survival. HAND2-AS1 over-expression reduced viability and proliferation in HCC cells. Elevated HAND2-AS1 level induced apoptosis in HCC cells, accompanied with increased Bax and cleaved caspase-3 levels and decreased Bcl-2 level. We also validated that HAND2-AS1 acted as a sponge of miR-300, and there was a negative correlation between expression levels of HAND2-AS1 and miR-300 in HCC tissues. Furthermore, we found that SOCS5 was a downstream target of miR-300. In addition, miR-300 mimics abolished HAND2-AS1-mediated inhibition of cell viability and proliferation. miR-300 mimics also reversed the HAND2-AS1-induced apoptosis in HCC cells.

CONCLUSION

lncRNA HAND2-AS1 inhibits proliferation in HCC through regulating miR-300/SOCS5 axis.

Recent Advances in Liver Cancer Stem Cells: Non-coding RNAs, Oncogenes and Oncoproteins

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide, with high morbidity, relapse, metastasis and mortality rates. Although liver surgical resection, transplantation, chemotherapy, radiotherapy and some molecular targeted therapeutics may prolong the survival of HCC patients to a certain degree, the curative effect is still poor, primarily because of tumor recurrence and the drug resistance of HCC cells. Liver cancer stem cells (LCSCs), also known as liver tumor-initiating cells, represent one small subset of cancer cells that are responsible for disease recurrence, drug resistance and death. Therefore, understanding the regulatory mechanism of LCSCs in HCC is of vital importance. Thus, new studies that present gene regulation strategies to control LCSC differentiation and replication are under development. In this review, we provide an update on the latest advances in experimental studies on non-coding RNAs (ncRNAs), oncogenes and oncoproteins. All the articles addressed the crosstalk between different ncRNAs, oncogenes and oncoproteins, as well as their upstream and downstream products targeting LCSCs. In this review, we summarize three pathways, the Wnt/β-catenin signaling pathway, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, and interleukin 6/Janus kinase 2/signal transducer and activator of transcription 3 (IL6/JAK2/STAT3) signaling pathway, and their targeting gene, c-Myc. Furthermore, we conclude that octamer 4 (OCT4) and Nanog are two important functional genes that play a pivotal role in LCSC regulation and HCC prognosis.

Long non-coding RNA SNHG3, induced by IL-6/STAT3 transactivation, promotes stem cell-like properties of gastric cancer cells by regulating the miR-3619-5p/ARL2 axis

BACKGROUND

Chemotherapy is, next to surgery and radiotherapy, the mainstay regimen for the clinical management of gastric cancer. This therapy is, however, heavily compromised by the acquisition of resistance. Here, we aimed to clarify the potential involvement of long non-coding RNA SNGH3 in the acquisition of cisplatin resistance and stemness in gastric cancer.

METHODS

Cell viability and proliferation were measured using Cell Counting Kit-8 and colony formation assays, respectively. Stem cell-like cell growth was evaluated using a mammosphere formation assay. RNA levels of SNHG2, OCT-4, SOX-2, CD44, miR-3619-5p and ARL2 were determined using qRT-PCR, whereas protein levels of OCT-4, SOX-2, CD44, ARL2, STAT3 and pSTAT3 were determined using Western blotting. Dual luciferase reporter assays were employed to interrogate regulatory interactions between STAT3, SNHG3, miR-3619-5p and ARL2, respectively. Direct binding of STAT3 to the SNHG3 promoter was investigated using a chromatin immunoprecipitation assay.

RESULTS

We found that IL-6 triggered stem cell-like properties in cisplatin-treated gastric cancer cells and activated STAT3, which in turn transcriptionally regulated SNHG3 expression. SNHG3 expression up-regulation positively correlated with cisplatin resistance and stemness of gastric cancer cells, while SNHG3 down-regulation inhibited stem cell-like properties. In addition, we found that SNHG3 up-regulated ARL2 expression through sponging miR-3619-5p, which predominantly mediated the oncogenic properties of SNHG3 in this disease.

CONCLUSIONS

Our data indicate an involvement of aberrant SNHG3 over-expression in the acquisition of both cisplatin resistance and stemness of gastric cancer cells, and of the IL-6/STAT3/SNHG3/miR-3619-5p/ARL2 signaling cascade in the oncogenic properties of SNHG3.

Dual Effects of Non-Coding RNAs (ncRNAs) in Cancer Stem Cell Biology

The identification of cancer stem cells (CSCs) as initiators of carcinogenesis has revolutionized the era of cancer research and our perception for the disease treatment options. Additional CSC features, including self-renewal and migratory and invasive capabilities, have further justified these cells as putative diagnostic, prognostic, and therapeutic targets. Given the CSC plasticity, the identification of CSC-related biomarkers has been a serious burden in CSC characterization and therapeutic targeting. Over the past decades, a compelling amount of evidence has demonstrated critical regulatory functions of non-coding RNAs (ncRNAs) on the exclusive features of CSCs. We now know that ncRNAs may interfere with signaling pathways, vital for CSC phenotype maintenance, such as Notch, Wnt, and Hedgehog. Here, we discuss the multifaceted contribution of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as representative ncRNA classes, in sustaining the CSC-like traits, as well as the underlying molecular mechanisms of their action in various CSC types. We further discuss the use of CSC-related ncRNAs as putative biomarkers of high diagnostic, prognostic, and therapeutic value.

Liver cancer stem cells as a hierarchical society: yes or no?

Cancer stem cells (CSCs) are cells possessing abilities of self-renewal, differentiation, and tumorigenicity in NOD/SCID mice. Based on this definition, multiple cell surface markers (such as CD24, CD133, CD90, and EpCAM) as well as chemical methods are discovered to enrich liver CSCs in the recent decade. Accumulated studies have revealed molecular signatures and signaling pathways involved in regulating different liver CSCs. Among liver CSCs positive for different markers, some molecular features and regulatory pathways are commonly shared, while some are only unique in certain CSC populations. These studies imply that liver CSCs exhibit diverse heterogeneity, while a functional relationship also exists. The aim of this review is to revisit the society of liver CSCs and summarize the common or unique molecular features of known liver CSCs. We hope to call for attention of researchers on the relationship of the liver CSC subgroups and to provide clues on the hierarchical structure of the liver CSC society.

Long noncoding RNA lnc-LOC645166 promotes adriamycin resistance via NF-κB/GATA3 axis in breast cancer

Chemoresistance remains a significant obstacle for effective adriamycin (ADR) treatment in breast cancer. Recent efforts have revealed that long noncoding RNAs (lncRNAs) play a crucial role in cancer biology, including chemoresistance. We identified the lncRNA LOC645166 was upregulated in adriamycin resistant-breast cancer cells by Microarray analysis, which was further confirmed in the tissues of nonresponsive patients by reverse transcription-quantitative polymerase chain reaction (RT–qPCR), western blotting, and immunohistochemical assays. Downregulation of lncRNA LOC645166 increased cell sensitivity to adriamycin both in vitro and in vivo. In contrast, upregulation of lncRNA LOC645166 strengthened the tolerance of breast cancer cells to adriamycin. Chromatin immunoprecipitation (ChIP) and RNA binding protein immunoprecipitation (RIP) demonstrated that lncRNA LOC645166 could increase the expression of GATA binding protein 3 (GATA3) via binding with nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), leading to the activation of STAT3 and promoting chemoresistance in breast cancer. Together, the present study suggested that lncRNA LOC645166 mediated adriamycin chemoresistance in breast cancer by regulating GATA3 via NF-κB.

The Underlying Mechanisms of Noncoding RNAs in the Chemoresistance of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal human malignancies. Chemotherapeutic agents, such as sorafenib and lenvatinib, can improve the outcomes of HCC patients. Nevertheless, chemoresistance has become a major hurdle in the effective treatment of HCC. Noncoding RNAs (ncRNAs), including mircoRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), have been demonstrated to participate in the onset and progression of HCC. Moreover, multiple lines of evidence have indicated that ncRNAs also play a pivotal role in HCC drug resistance. ncRNAs can regulate drug efflux and metabolism, glucose metabolism, cellular death pathways, and malignant characteristics in HCC. A deeper understanding of the molecular mechanisms responsible for ncRNA-mediated drug resistance in HCC will provide new opportunities for improving the treatment of HCC. In this review, we summarize recent findings on the molecular mechanisms by which ncRNAs regulate HCC chemoresistance, as well as their potential clinical implications in overcoming HCC chemoresistance.

MicroRNA-Based Combinatorial Cancer Therapy: Effects of MicroRNAs on the Efficacy of Anti-Cancer Therapies

The susceptibility of cancer cells to different types of treatments can be restricted by intrinsic and acquired therapeutic resistance, leading to the failure of cancer regression and remission. To overcome this problem, a combination therapy has been proposed as a fundamental strategy to improve therapeutic responses; however, resistance is still unavoidable. MicroRNA (miRNAs) are associated with cancer therapeutic resistance. The modulation of dysregulated miRNA levels through miRNA-based therapy comprising a replacement or inhibition approach has been proposed to sensitize cancer cells to other anti-cancer therapies. The combination of miRNA-based therapy with other anti-cancer therapies (miRNA-based combinatorial cancer therapy) is attractive, due to the ability of miRNAs to target multiple genes associated with the signaling pathways controlling therapeutic resistance. In this article, we present an overview of recent findings on the role of therapeutic resistance-related miRNAs in different types of cancer. We review the feasibility of utilizing dysregulated miRNAs in cancer cells and extracellular vesicles as potential candidates for miRNA-based combinatorial cancer therapy. We also discuss innate properties of miRNAs that need to be considered for more effective combinatorial cancer therapy.

Identification of a Diagnostic Set of Endomyocardial Biopsy microRNAs for Acute Cellular Rejection Diagnostics in Patients after Heart Transplantation Using Next-Generation Sequencing

Introduction: Acute cellular rejection (ACR) of heart allografts represents the most common reason for graft failure. Endomyocardial biopsies (EMB) are still subject to substantial interobserver variability. Novel biomarkers enabling precise ACR diagnostics may decrease interobserver variability. We aimed to identify a specific subset of microRNAs reflecting the presence of ACR. Patients and Methods: Monocentric retrospective study. A total of 38 patients with the anamnesis of ACR were identified and for each patient three consecutive samples of EMB (with, prior and after ACR) were collected. Sixteen trios were used for next-generation sequencing (exploratory cohort); the resting 22 trios were used for validation with qRT-PCR (validation cohort). Statistical analysis was performed using R software. Results: The analysis of the exploration cohort provided the total of 11 miRNAs that were altered during ACR, the three of which (miR-144, miR-589 and miR-182) were further validated in the validation cohort. Using the levels of all 11 miRNAs and principal component analysis, an ACR score was created with the specificity of 91% and sensitivity of 68% for detecting the presence of ACR in the EMB sample. Conclusion: We identified a set of microRNAs altered in endomyocardial biopsies during ACR and using their relative levels we created a diagnostic score that can be used for ACR diagnosis.

Targeting Thyroid Receptor Interacting Protein 6 by MicroRNA-589-5p Inhibits Cell Proliferation, Migration, and Invasion in Endometrial Carcinoma

Background: MicroRNA-589-5p (miR-589-5p) has been recently reported to be aberrantly regulated in hepatocellular carcinoma, but its functional role and molecular mechanisms still remains unknown in the endometrial carcinoma (EC) as one of the most common female malignancies. Methods: EC tissues and adjacent tissues were collected to determine the expression of miR-589-5p and thyroid receptor interacting protein 6 (TRIP6) using quantitative real time-PCR. Subsequently, two EC cell lines HEC-1B and AN3CA were transfected with miR-589-5p to achieve miR-589-5p overexpression. Using Cell Counting Kit-8 (CCK-8), a wound healing assay and the Transwell assay, we analyzed cell proliferation, migration and invasion. Dual-luciferase reporter assay confirmed that thyroid receptor interacting protein 6 (TRIP6) was a direct target of miR-589-5p. Results: We first observed that miR-589-5p was down-regulated in EC tissues compared with normal endometrial tissues. MiR-589-5p overexpression significantly suppressed EC cell proliferation, migration and invasion. Thyroid receptor interacting protein 6 (TRIP6) was a direct target of miR-589-5p. Besides, TRIP6 knockdown presented similar effects on cell proliferation, migration and invasion to miR-589-5p overexpression. Furthermore, TRIP6 knockdown efficiently enhanced the effects of miR-589-5p on the above cellular function. Moreover, miR-589-5p up-regulated E-cadherin expression, but down-regulated N-cadherin and Vimentin by targeting TRIP6. Conclusions: In summary, miR-589-5p might function as a tumor suppressor by targeting TRIP6, which will provide new insights into the molecular mechanism underlying the development of EC.

Overexpression of miR-25 is associated with progression and poor prognosis of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a rare but highly aggressive type of malignancy. MicroRNA (miR)-25 has been demonstrated to be involved in the genesis of numerous cancer types. The aim of the present study was to investigate the prognostic value and functional role of miR-25 in CCA. The expression of miR-25 was determined by reverse transcription-quantitative (RT-q)PCR. The association between miR-25 expression and clinicopathological features was analyzed using the χ² test. Kaplan-Meier survival analysis and Cox linear regression were performed to explore the prognostic value of miR-25. The effects of miR-25 on the biological behavior of CCA cells were determined using loss-and gain-of-function experiments in CCA cell lines. Upregulated miR-25 expression was observed in CCA tissues and cell lines compared with that in the respective controls (all P<0.05). Patients with high expression of miR-25 in CCA tissues had a comparatively higher tumor-nodes-metastasis stage (P=0.026), a higher rate of lymph node metastasis (P=0.032) and a shorter overall survival rate (log-rank P=0.022). miR-25 was determined to be an independent prognostic factor for CCA patients (P=0.036). In vitro, transfection with miR-25 inhibitor suppressed cell viability, migration and invasion, while miR-25 mimics had the opposite effect. These results indicated that miR-25 functions as an oncogene and is involved in tumor progression in CCA. miR-25 may serve as a prognostic biomarker and a potential therapeutic target for CCA treatment.

Hepatocellular carcinoma: Mechanisms of progression and immunotherapy

Liver cancer is one of the most common malignancies, and various pathogenic factors can lead to its occurrence and development. Among all primary liver cancers, hepatocellular carcinoma (HCC) is the most common. With extensive studies, an increasing number of molecular mechanisms that promote HCC are being discovered. Surgical resection is still the most effective treatment for patients with early HCC. However, early detection and treatment are difficult for most HCC patients, and the postoperative recurrence rate is high, resulting in poor clinical prognosis of HCC. Although immunotherapy takes longer than conventional chemotherapy to produce therapeutic effects, it persists for longer. In recent years, the emergence of many new immunotherapies, such as immune checkpoint blockade and chimeric antigen receptor T cell therapies, has given new hope for the treatment of HCC.

MicroRNA-589 serves as a tumor suppressor microRNA through directly targeting metastasis-associated protein 2 in breast cancer

Triple-negative breast cancer (TNBC) has a poorer outcome compared with that of other subtypes of breast cancer, and the discovery of dysregulated microRNA (miRNA) and their role in tumor progression has provided a new avenue for elucidating the mechanism involved in TNBC. Previous studies have revealed that aberrant expression of miRNA-589 (miR-589) was frequently observed in various types of cancer. However, the expression and function of miR-589 in TNBC has not been well illustrated. In the present study, the expression level of miR-589 was explored in TNBC tissues and TNBC cell lines by quantitative polymerase chain reaction (qPCR). The results revealed that the expression of miR-589 was decreased in TNBC tissues and cell lines compared with that in normal tissues and breast cell lines. Furthermore, miR-589 overexpression decreased the TNBC cell proliferation, migration and invasion, whereas miR-589 silencing generated the opposite results in vitro. Bioinformatic algorithms predicted a direct target site for miR-589 in the 3′-untranslated region of metastasis-associated protein 2 (MTA2), which was confirmed with a dual-luciferase reporter assay and western blot analysis. Results of the qPCR and western blot analysis illustrated that miR-589 negatively regulated MTA2 expression with regard to mRNA and protein levels in the TNBC cell lines. MTA2 silencing reversed the promotion function of miR-589 inhibitor in the TNBC cell line. Finally, miR-589 could inhibit the process of epithelial-mesenchymal transition via MTA2. In summary, the present study revealed the biological function and molecular mechanism of miR-589 in the progression of TNBC. MiR-589 inhibition in the progression of TNBC may be a potential therapeutic target for TNBC.

Aquaporin 3 maintains the stemness of CD133+ hepatocellular carcinoma cells by activating STAT3

An increasing interest in liver cancer stemness arises owing to its aggressive behavior and poor prognosis. CD133, a widely known liver cancer stem cell marker, plays critical roles in the maintenance of liver cancer stemness. Thus, exploring the regulatory mechanism of CD133 expression is significant. In the present study, we proved the carcinogenesis roles of aquaporin 3 (AQP3) in hepatocellular carcinoma (HCC) and demonstrated that AQP3 promotes the stem cell-like properties of hepatoma cells by regulating CD133 expression. In addition, AQP3 promoted the stimulation and nuclear translocation of signal transducer and activator of transcription 3 (STAT3) with a subsequent increase in the level of CD133 promoter-acetylated histone H3. This phenomenon accelerated CD133 transcription. Next, whether AQP3 acted as an oncogenic gene in HCC and maintained the stemness of CD133+ hepatoma cells were elucidated; also, a novel mechanism underlying the AQP3/STAT3/CD133 pathway in HCC was deduced.

Salidroside inhibits migration and invasion of poorly differentiated thyroid cancer cells

Background

No effective treatment is currently available for poorly differentiated thyroid cancer which is resistant to radioiodine, especially with migration and invasion. A great number of researches have revealed the anticancer effects of salidroside, but none have studied the effects of salidroside on thyroid cancer. This study aimed to investigate the effect of salidroside on migration and invasion of poorly differentiated thyroid cancer cells.

Methods

The effects of salidroside on migration, invasion and apoptosis of poorly differentiated thyroid cancer WRO cells and normal thyroid follicular epithelial Nthy‐ori 3‐1 cells were measured by wound‐healing assay, transwell migration/invasion assay and flow cytometry, respectively. The expression levels of MMP2 and MMP9 at RNA and protein levels in WRO cells were detected by qRT‐PCR and western blot. The phosphorylation levels of Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3) and the apoptosis‐related protein levels of Bax, cleaved caspase 3 and Bcl‐2 were assessed by western blot.

Results

Salidroside significantly suppressed migration/invasion and induced apoptosis in poorly differentiated thyroid cancer WRO cells. We further illustrated that salidroside significantly inhibited expressions of MMP2 and MMP9 at mRNA and protein levels and the phosphorylation activation of JAK2/STAT3 in WRO cells. In addition, salidroside increased expressions of pro‐apoptotic factors (Bax and cleaved caspase 3) and decreased expression of anti‐apoptotic factor (Bcl‐2) significantly in WRO cells.

Conclusion

The present study demonstrates that salidroside inhibits migration and invasion of WRO cells (a kind of poorly differentiated cancer cell line) significantly, which might be via suppressing JAK2‐STAT3 signaling pathway.

MicroRNA-196a/-196b regulate the progression of hepatocellular carcinoma through modulating the JAK/STAT pathway via targeting SOCS2

microRNAs (miRNAs) play essential roles in progression of hepatocellular carcinoma (HCC). However, the roles of miR-196a and miR-196b as well as mechanism in HCC progression remain poorly understood. The expressions of miR-196a, miR-196b and suppressor of cytokine signaling 2 (SOCS2) were measured in HCC tissues and cells by quantitative real-time polymerase chain reaction or immunohistochemistry. HCC progression was investigated by cell proliferation, glycolysis, cycle, clones, apoptosis, and necrosis. The interaction between SOCS2 and miR-196a or miR-196b was explored by luciferase activity and RNA immunoprecipitation analyses. The expressions of proteins in Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway were measured by western blot. A xenograft model was established to investigate the roles of miR-196a or miR-196b in vivo. We found that miR-196a and miR-196b were highly expressed in HCC tissues and cells. High expression of miR-196a or miR-196b was correlated with tumor size, tumor-node-metastasis stage, lymph node metastasis, albumin–bilirubin grade and poor 5-year survival. Knockdown of miR-196a or miR-196b suppressed cell proliferation, glycolysis, cell cycle process, colony formation but induced apoptosis or necrosis in HCC cells. SOCS2 was targeted by miR-196a and miR-196b and its interference ablated abrogation of miR-196a or miR-196b-mediated inhibitory effect on HCC progression. SOCS2 was negatively associated with activation of the JAK/STAT pathway. Besides, knockdown of miR-196a or miR-196b limited xenograft tumor growth by blocking the JAK/STAT pathway. We concluded that downregulation of miR-196a or miR-196b inhibited HCC progression through regulating the JAK/STAT pathway via targeting SOCS2, providing novel targets for prognosis and therapeutics of HCC.

Diverse perspectives to address for the future treatment of heterogeneous hepatocellular carcinoma

Hepatocellular carcinomas (HCCs), which often arise from chronic liver damage, have poor conditional 5-year survival and are recognized as heterogeneous tumors. Considering the heterogeneity of HCCs, diverse perspectives need to be addressed for treating such tumors, besides the findings of conventional imaging modalities and tumor markers. Data from the latest technologies, such as liquid biopsy, and the detection of the presence of cancer cells with stem/progenitor cell markers, gene mutations and diverse pathways, crosstalk with immune cells and cancer-associated fibroblasts, and mechanisms of epithelial–mesenchymal transition provide diverse lines of information. Integration of these data with clinical data might be necessary to develop effective therapies for precision medicine. Here, we review several aspects of dealing with the complexity of heterogeneous HCCs.

STAT1-mediated inhibition of FOXM1 enhances gemcitabine sensitivity in pancreatic cancer

Forkhead box protein M1 (FOXM1) was identified as an oncogenic transcription factor and master regulator of tumor progression and metastasis. FOXM1 expression often correlates with poor prognosis and chemotherapy resistance. In the present study, we investigated the association of FOXM1 expression and chemoresistance in pancreatic cancer. Elevated FOXM1 protein levels were associated with gemcitabine chemoresistance in patients with pancreatic cancer. In gemcitabine resistance cell line models of pancreatic cancer, FOXM1 expression increased, which induced gemcitabine chemoresistance in vitro. In pancreatic cancer cells treated with gemcitabine, FOXM1 affected nuclear factor κB (NF-κB) signaling activity. Immunohistochemical analysis demonstrated a negative association of FOXM1 expression and the level of phosphorylated signal transducer and activator of transcription 1 (pSTAT1) in human pancreatic cancer tissues. Dual-luciferase reporter assays and chromatin-immunoprecipitation assays demonstrated that pSTAT1 directly binds to the FOXM1 promoter to down-regulate its transcription. Interferon γ (IFNγ) promoted gemcitabine-induced cell apoptosis and inhibited cell proliferation in vitro and in vivo by FOXM1 inhibition. These data suggested that FOXM1 enhances chemoresistance to gemcitabine in pancreatic cancer. IFNγ could be used to down-regulate the expression of FOXM1 through STAT1 phosphorylation, thereby increasing the sensitivity of pancreatic cancer cells to gemcitabine. These studies suggested the sensitization by IFNγ in pancreatic ductal adenocarcinoma (PDAC) chemotherapy, which requires further clinical studies.