miR-122 inhibits cancer cell malignancy by targeting PKM2 in gallbladder carcinoma

Identification of tumor-suppressive miRNAs that target amino acid transporter LAT1 and exhibit anti-proliferative effects on cholangiocarcinoma cells

Amino acid transporter LAT1 is highly upregulated in various cancer types, including cholangiocarcinoma (CHOL), and contributes to the rapid proliferation of cancer cells and disease progression. However, the molecular mechanisms underlying the pathological upregulation of LAT1 remain largely unknown. This study pursued the possibility of miRNA-mediated regulation of the LAT1 expression in CHOL cells. Using online target prediction methods, we extracted five candidate miRNAs commonly predicted to regulate the LAT1 expression. Three of them, miR-194-5p, miR-122-5p, and miR-126-3p, were significantly downregulated in CHOL cancer compared to normal tissues. Correlation analysis revealed weak-to-moderate negative correlations between the expression of these miRNAs and LAT1 mRNA in CHOL cancer tissues. We selected miR-194-5p and miR-122-5p for further analyses and found that both miRNAs functionally target 3'UTR of LAT1 mRNA by a luciferase-based reporter assay. Transfection of the miRNA mimics significantly suppressed the LAT1 expression at mRNA and protein levels and inhibited the proliferation of CHOL cells, with a trend of affecting intracellular amino acids and amino acid-related signaling pathways. This study indicates that the decreased expression of these LAT1-targeting tumor-suppressive miRNAs contributes to the upregulation of LAT1 and the proliferation of CHOL cells, highlighting their potential for developing novel cancer therapeutics and diagnostics.

MicroRNA-122 in human cancers: from mechanistic to clinical perspectives

MicroRNAs (miRNAs) are endogenous short non-coding RNAs that can regulate the expression of target genes post-transcriptionally and interact with mRNA-coding genes. MiRNAs play vital roles in many biological functions, and abnormal miRNA expression has been linked to various illnesses, including cancer. Among the miRNAs, miR-122, miR-206, miR-21, miR-210, miR-223, and miR-424 have been extensively studied in various cancers. Although research in miRNAs has grown considerably over the last decade, much is yet to be discovered, especially regarding their role in cancer therapies. Several kinds of cancer have been linked to dysregulation and abnormal expression of miR-122, indicating that miR-122 may serve as a diagnostic and/or prognostic biomarker for human cancer. Consequently, in this review literature, miR-122 has been analyzed in numerous cancer types to sort out the function of cancer cells miR-122 and enhance patient response to standard therapy.

Non-coding RNAs as potential biomarkers of gallbladder cancer

Gallbladder cancer (GBC) performs strongly invasive and poor prognosis, and adenocarcinoma is the most common histological type in it. Statistically, the 5-year survival rate of patients with advanced GBC is less than 5%. Such dismal outcome might be caused by chemotherapy resistance and native biology of tumor cells, regardless of emerging therapeutic strategies. Early diagnosis, depending on biomarkers, receptors and secretive proteins, is more important than clinical therapy, guiding the pathologic stage of cancer and the choice of medication. Therefore, it is in urgent need to understand the specific pathogenesis of GBC and strive to find promising novel biomarkers for early screening in GBC. Non-coding RNAs (ncRNAs), especially microRNAs (miRNAs, miRs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are confirmed to participate in and regulate the occurrence and development of GBC. Exceptionally, lncRNAs and circRNAs could act as competing endogenous RNAs (ceRNAs) containing binding sites for miRNAs and crosstalk with miRNAs to target regulatory downstream protein-coding messenger RNAs (mRNAs), thus affecting the expression levels of specific proteins to participate in and regulate the development and progression of GBC. It follows that ncRNAs may become promising biomarkers and potential therapeutic targets for GBC. In this review, we mainly summarize the recent research progress of miRNAs and lncRNAs in regulating the development and progression of GBC, chemoresistance, and predicting the prognosis of patients, and highlight the potential applications of the lncRNA/circRNA-miRNA-mRNA cross-regulatory networks in early diagnosis, chemoresistance, and prognostic evaluation, aiming to better understand the pathogenesis of GBC and develop new diagnostic and therapeutic strategies.

YB1 regulates miR-205/200b-ZEB1 axis by inhibiting microRNA maturation in hepatocellular carcinoma

BACKGROUND

Y-box binding protein 1 (YB1 or YBX1) plays a critical role in tumorigenesis and cancer progression. However, whether YB1 affects malignant transformation by modulating non-coding RNAs remains largely unknown. This study aimed to investigate the relationship between YB1 and microRNAs and reveal the underlying mechanism by which YB1 impacts on tumor malignancy via miRNAs-mediated regulatory network.

METHODS

The biological functions of YB1 in hepatocellular carcinoma (HCC) cells were investigated by cell proliferation, wound healing, and transwell invasion assays. The miRNAs dysregulated by YB1 were screened by microarray analysis in HCC cell lines. The regulation of YB1 on miR-205 and miR-200b was determined by quantitative real-time PCR, dual-luciferase reporter assay, RNA immunoprecipitation, and pull-down assay. The relationships of YB1, DGCR8, Dicer, TUT4, and TUT1 were identified by pull-down and coimmunoprecipitation experiments. The cellular co-localization of YB1, DGCR8, and Dicer were detected by immunofluorescent staining. The in vivo effect of YB1 on tumor metastasis was determined by injecting MHCC97H cells transduced with YB1 shRNA or shControl via the tail vein in nude BALB/c mice. The expression levels of epithelial to mesenchymal transition markers were detected by immunoblotting and immunohistochemistry assays.

RESULTS

YB1 promoted HCC cell migration and tumor metastasis by regulating miR-205/200b-ZEB1 axis partially in a Snail-independent manner. YB1 suppressed miR-205 and miR-200b maturation by interacting with the microprocessors DGCR8 and Dicer as well as TUT4 and TUT1 via the conserved cold shock domain. Subsequently, the downregulation of miR-205 and miR-200b enhanced ZEB1 expression, thus leading to increased cell migration and invasion. Furthermore, statistical analyses on gene expression data from HCC and normal liver tissues showed that YB1 expression was positively associated with ZEB1 expression and remarkably correlated with clinical prognosis.

CONCLUSION

This study reveals a previously undescribed mechanism by which YB1 promotes cancer progression by regulating the miR-205/200b-ZEB1 axis in HCC cells. Furthermore, these results highlight that YB1 may play biological functions via miRNAs-mediated gene regulation, and it can serve as a potential therapeutic target in human cancers.

The Role of PKM2 in Metabolic Reprogramming: Insights into the Regulatory Roles of Non-Coding RNAs

Pyruvate kinase is a key regulator in glycolysis through the conversion of phosphoenolpyruvate (PEP) into pyruvate. Pyruvate kinase exists in various isoforms that can exhibit diverse biological functions and outcomes. The pyruvate kinase isoenzyme type M2 (PKM2) controls cell progression and survival through the regulation of key signaling pathways. In cancer cells, the dimer form of PKM2 predominates and plays an integral role in cancer metabolism. This predominance of the inactive dimeric form promotes the accumulation of phosphometabolites, allowing cancer cells to engage in high levels of synthetic processing to enhance their proliferative capacity. PKM2 has been recognized for its role in regulating gene expression and transcription factors critical for health and disease. This role enables PKM2 to exert profound regulatory effects that promote cancer cell metabolism, proliferation, and migration. In addition to its role in cancer, PKM2 regulates aspects essential to cellular homeostasis in non-cancer tissues and, in some cases, promotes tissue-specific pathways in health and diseases. In pursuit of understanding the diverse tissue-specific roles of PKM2, investigations targeting tissues such as the kidney, liver, adipose, and pancreas have been conducted. Findings from these studies enhance our understanding of PKM2 functions in various diseases beyond cancer. Therefore, there is substantial interest in PKM2 modulation as a potential therapeutic target for the treatment of multiple conditions. Indeed, a vast plethora of research has focused on identifying therapeutic strategies for targeting PKM2. Recently, targeting PKM2 through its regulatory microRNAs, long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) has gathered increasing interest. Thus, the goal of this review is to highlight recent advancements in PKM2 research, with a focus on PKM2 regulatory microRNAs and lncRNAs and their subsequent physiological significance.

Pathogenetic Role and Clinical Implications of Regulatory RNAs in Biliary Tract Cancer

Biliary tract cancer (BTC) is characterised by poor prognosis and low overall survival in patients. This is generally due to minimal understanding of its pathogenesis, late diagnosis and limited therapeutics in preventing or treating BTC patients. Non-coding RNA (ncRNA) are small RNAs (mRNA) that are not translated to proteins. ncRNAs were considered to be of no importance in the genome, but recent studies have shown they play essential roles in biology and oncology such as transcriptional repression and degradation, thus regulating mRNA transcriptomes. This has led to investigations into the role of ncRNAs in the pathogenesis of BTC, and their clinical implications. In this review, the mechanisms of action of ncRNA are discussed and the role of microRNAs in BTC is summarised. The scope of this review will be limited to miRNA as they have been shown to play the most significant roles in BTC progression. There is huge potential in miRNA-based biomarkers and therapeutics in BTC, but more studies, research and technological advancements are required before it can be translated into clinical practice for patients.

Overview of current targeted therapy in gallbladder cancer

Gallbladder cancer (GBC) is rare, but is the most malignant type of biliary tract tumor. Unfortunately, only a small population of cancer patients is acceptable for the surgical resection, the current effective regimen; thus, the high mortality rate has been static for decades. To substantially circumvent the stagnant scenario, a number of therapeutic approaches owing to the creation of advanced technologic measures (e.g., next-generation sequencing, transcriptomics, proteomics) have been intensively innovated, which include targeted therapy, immunotherapy, and nanoparticle-based delivery systems. In the current review, we primarily focus on the targeted therapy capable of specifically inhibiting individual key molecules that govern aberrant signaling cascades in GBC. Global clinical trials of targeted therapy in GBC are updated and may offer great value for novel pathologic and therapeutic insights of this deadly disease, ultimately improving the efficacy of treatment.

SNHG3 Functions as miRNA Sponge to Promote Breast Cancer Cells Growth Through the Metabolic Reprogramming

Cancer-associated fibroblasts (CAFs) are important ingredient in tumor microenvironment. The dynamic interplay between CAFs and cancer cells plays essential roles during tumor development and progression. However, the mechanisms of intercellular communication between CAFs and cancer cells remain largely unknown. We characterized exosomes secreted from breast cancer patient-derived CAFs by transmission electron microscopy. The expression of SNHG3, miR-330-5p, and PKM (Pyruvate Kinase M1/M2) was examined by real-time QPCR and immunoblot. The function of SNHG3 on the growth and metabolism of tumor cells was used by CCK8 and mitochondrial oxygen consumption assays. The binding between SNHG3, miR-330-5p, and PKM was examined by dual luciferase reporter assays. Orthotopical xenograft of breast tumor experiments was performed to determine the function of SNHG3 in vivo. We demonstrated that exosomes secreted from CAFs reprogram the metabolic pathways after tumor cells uptake the exosomes. CAF-secreted exosomal lncRNA SNHG3 served as a molecular sponge for miR-330-5p in breast cancer cells. Moreover, PKM could be targeted by miR-330-5p and was controlled by SNHG3 in breast cancer cells. Mechanistically, SNHG3 knockdown in CAF-secreted exosomes suppressed glycolysis metabolism and cell proliferation by the increase of miR-330-5p and decrease of PKM expression in tumor cells. SNHG3 functions as a miR-330-5p sponge to positively regulate PKM expression, inhibit mitochondrial oxidative phosphorylation, increase glycolysis carboxylation, and enhance breast tumor cell proliferation. Overall, SNHG3 could play a major role in the development and progression of breast cancer and support the therapeutic potential of targeting communication between cancer cells and tumor microenvironment.

Potential Onco-Suppressive Role of miR122 and miR144 in Uveal Melanoma through ADAM10 and C-Met Inhibition

Uveal melanoma (UM) is a rare tumor of the eye that leads to deadly metastases in about half of the patients. ADAM10 correlates with c-Met expression in UM and high levels of both molecules are related to the development of metastases. MiR122 and miR144 modulate ADAM10 and c-Met expression in different settings. We hypothesized a potential onco-suppressive role for miR122 and miR144 through modulation of ADAM10 and c-Met in UM. We analyzed the UM Cancer Genome Atlas data portal (TCGA) dataset, two other cohorts of primary tumors and five human UM cell lines for miR122 and miR144 expression by miR microarray, RT-qPCR, Western blotting, miR transfection and luciferase reporter assay. Our results indicate that miR122 and miR144 are expressed at low levels in the UM cell lines and in the TCGA UM dataset and were down-modulated in a cohort of seven UM samples, compared to normal choroid. Both miR122 and miR144 directly targeted ADAM10 and c-Met. Overexpression of miR122 and miR144 led to reduced expression of ADAM10 and c-Met in the UM cell lines and impaired cell proliferation, migration, cell cycle and shedding of c-Met ecto-domain. Our results show that miR122 and miR144 display an onco-suppressive role in UM through ADAM10 and c-Met modulation.

MiR-122-5p suppresses the proliferation, migration, and invasion of gastric cancer cells by targeting LYN

Gastric cancer (GC) is one of malignant tumors with high mortality and morbidity in the world. MicroRNA-122 (miR-122) acts as a tumor suppressor in a variety of cancers and has been found to be dominant in gastric adenocarcinoma. However, the specific biological function of miR-122-5p in GC is not completely clear. In this study, we found that miR-122-5p was low-expressed in GC tissues and cell lines by using qRT-PCR. Overexpression of miR-122-5p inhibited the proliferation, migration, and invasion of GC cells by using CCK-8 and transwell assays. On the contrary, downregulation of miR-122-5p promoted the proliferation, migration, and invasion of GC cells. In addition, we found that the expression of LYN, an Src family tyrosine kinase, was inversely correlated with miR-122-5p expression in GC tissues by using western blot analysis, immunohistochemistry, and qRT-PCR assays. Meanwhile, luciferase assay results indicated that LYN is a direct target of miR-122-5p in GC cells. Moreover, silencing LYN expression by its siRNA inhibited the proliferation, migration, and invasion of GC cells. Importantly, overexpression of LYN restored miR-122-5p-mediated inhibition of the proliferation, migration, and invasion of GC cells. Taken together, our results indicated miR-122-5p inhibited the proliferation, migration, and invasion by targeting LYN in GC.

BMSC-derived exosomes carrying microRNA-122-5p promote proliferation of osteoblasts in osteonecrosis of the femoral head

Mesenchymal stem cells (MSCs) with multipotential differentiation capacity can differentiate into bone cells under specific conditions and can be used to treat osteonecrosis (ON) of the femoral head (ONFH) through cell transplantation. The current study aims to explore the role of bone marrow (BM) MSCs (BMSCs)-derived exosomes carrying microRNA-122-5p (miR-122-5p) in ONFH rabbit models.First, rabbit models with ONFH were established. ONFH-related miRNAs were screened using the Gene Expression Omnibus (GEO) database. A gain-of-function study was performed to investigate the effect of miR-122-5p on osteoblasts and BMSCs and effects of exosomes carrying miR-122-5p on ONFH. Co-culture experiments for osteoblasts and BMSCs were performed to examine the role of exosomal miR-122-5p in osteoblast proliferation and osteogenesis. The target relationship between miR-122-5p and Sprouty2 (SPRY2) was tested.MiR-122, significantly decreased in ONFH in the GSE89587 expression profile, was screened. MiR-122-5p negatively regulated SPRY2 and elevated the activity of receptor tyrosine kinase (RTK), thereby promoting the proliferation and differentiation of osteoblasts. In vivo experiments indicated that bone mineral density (BMD), trabecular bone volume (TBV), and mean trabecular plate thickness (MTPT) of femoral head were increased after over-expressing miR-122-5p in exosomes. Significant healing of necrotic femoral head was also observed.Exosomes carrying over-expressed miR-122-5p attenuated ONFH development by down-regulating SPRY2 via the RTK/Ras/mitogen-activated protein kinase (MAPK) signaling pathway. Findings in the present study may provide miR-122-5p as a novel biomarker for ONFH treatment.

Clinical value of miRNA-122 in the diagnosis and prognosis of various types of cancer

The present study aimed to systematically analyze the value of microRNA-122 (miRNA-122) in the diagnosis and prognosis of hepatocellular carcinoma (HCC) and other types of cancer. First, the reverse transcription-quantitative polymerase chain reaction method was used to detect the expression levels of miRNA-122 in the serum samples of patients with HCC, benign lesions and healthy volunteers. Next, miRNA-seq data of miRNA-122 from The Cancer Genome Atlas database were used to analyze the differential expression and overall survival rate associated with a variety of types of cancer. Meanwhile, the target gene prediction of miRNA-122 was performed using four different software programs. Finally, 353 significant target genes were identified for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis. Finally, it was demonstrated that the expression levels of miRNA-122 in the HCC group were increased compared with the healthy group (P<0.001), but decreased with respect to the benign group (P<0.001). In addition, the combination of the miRNA-122 and a fetoprotein may further improve the diagnostic accuracy between the HCC and healthy groups (area under the curve, 0.980; 95% confidence interval, 0.958–1.000). It was also demonstrated that miRNA-122 exhibited significantly differential expression and the overall survival rate was predicted for various other types of cancer, including colorectal cancer, renal carcinoma, cholangiocarcinoma, prostate cancer and thyroid carcinoma. Functional enrichment analysis demonstrated that the target genes of miRNA-122 may contribute to the composition of the nucleus and cytoplasm, and regulate a variety of biological processes, including cardiac muscle cell differentiation and glucose metabolic processes via protein biosynthesis, estrogen and glucagon associated signaling pathways. These results revealed that miRNA-122 may be an indispensable biomarker for the diagnosis, prognostic evaluation and targeted therapy in pan-cancer.

Pyruvate kinase M2 inhibits the progression of bladder cancer by targeting MAKP pathway

Purpose

Pyruvate kinase M2 (PKM2) was found overexpressed in tumor cells and played a significant role in tumor formation and growth. We sought to explore the correlation of PKM2 expression with cell proliferation, invasion, and apoptosis in bladder cancer cell line.

Materials and Methods

Real-time polymerase chain reaction and Western blot were performed to determine the expression level of PKM2 at mRNA and protein level. MTT and flow cytometry were respectively used to explore the proliferation, invasion, and apoptosis in bladder cancer cell line in vitro.

Results

The results suggested that suppression of PKM2 significantly decreased the proliferation rate, invasive cell number, and migration ability of bladder cancer cells compared with blank group. Moreover, proteins such as MMP2 and MMP9 as well as P38 expression were also affected by the PKM2 expression changes. These results proved that PKM2 could be involved in the progression of bladder cancer by mitogen-activated protein kinases signaling pathway.

Conclusion

The data presented in this study revealed that PKM2 up-regulation may promote the development and metastasis of bladder cancer through promoting cell proliferation, migration and invasion via MAPK signal pathway.

miR-122-5p as a novel biomarker for alpha-fetoprotein-producing gastric cancer

AIM

To investigate the clinical utility of alpha-fetoprotein (AFP)-producing gastric cancer (AFPGC)-specific microRNA (miRNA) for monitoring and prognostic prediction of patients.

METHODS

We performed a comprehensive miRNA array-based approach to compare miRNA expression levels between AFP-positive and AFP-negative cells in three patients with primary AFPGC. We next examined the expression levels of the selected miRNAs in five AFPGC and ten non-AFPGC tissue samples by quantitative reverse transcription-polymerase chain reaction to validate their utility. We also investigated the expression levels of the selected miRNA not only in tissue but also in plasma samples. Moreover, we investigated the relationship between plasma AFP levels and plasma selected miRNA expression levels, and also investigated the correlation of the selected miRNA expression levels and malignant potential.

RESULTS

Among the five miRNAs selected from the miRNA array results, the expression levels of miR-122-5p were significantly higher in the AFPGC patients than in the non-AFPGC patients (P < 0.05). In tissue samples, miR-122-5p expression level tended to be lower in the non-AFPGC tissue than the normal gastric mucosa. Conversely, in the AFPGC tissue, miR-122-5p expression level was significantly higher in the AFPGC tissue than both the normal gastric mucosa and the non-AFPGC tissue samples (P < 0.05). Plasma miR-122-5p expression levels were also significantly higher in the AFPGC patients than the health volunteers and the non-AFPGC patients (P < 0.05) and were strongly correlated with plasma AFP levels (r = 0.7975, P < 0.0001). Moreover, the correlation of miR-122-5p expression in tissue samples with malignant potential was stronger than that of plasma AFP level in the AFPGC patients. In contrast, no correlation was found between miR-122-5p expression levels and liver metastasis in the non-AFPGC patients.

CONCLUSION

miR-122-5p might be a useful biomarker for early detection and disease monitoring in AFPGC.

Metabolic Switch in the Tumor Microenvironment Determines Immune Responses to Anti-cancer Therapy

Tumor-induced immune tolerance permits growth and spread of malignant cells. Cancer cells have strong influence on surrounding cells and shape the hypoxic tumor microenvironment (TME) facilitating cancer progression. A dynamic change in glucose metabolism occurring in cancer cells and its influence on the TME are still poorly understood. Indeed, cancer and/or immune cells undergo rapid adaptation in metabolic pathways during cancer progression. Metabolic reprograming affects macrophages, T cells, and myeloid derived suppressor cells (MDSCs) among other immune cells. Their role in the TME depends on a nature and concentration of factors, such as cytokines, reactive oxygen species (ROS), growth factors, and most importantly, diffusible metabolites (i.e., lactate). Further, the amounts of available nutrients and oxygen as well as activity of microbiota may influence metabolic pathways in the TME. The roles of metabolites in regulating of the interaction between immune and cancer cell are highlighted in this review. Targeting metabolic reprogramming or signaling pathways controlling cell metabolism in the TME might be a potential strategy for anti-cancer therapy alone or in combination with current immunotherapies.

Synergistic anticancer effects of nanocarrier loaded with berberine and miR-122

We introduced polyethyleneimine (PEI)-cholesterol (PC) as a nanocarrier incorporating berberine (BER) and miR-122 for the treatment of oral squamous cell carcinoma (OSCC). BER was stabilized by incorporating PC to form ber-PC. Ber-PC was further electrostatically complexed with miR-122 to yield mr-ber-PC for the co-delivery of BER and miR-122. mr-ber-PC treatment dramatically decreased the level of invasion and migration of OSCC cells compared with single drug treatments. The present study suggested that PC could be a multifunctional nanocarrier for the co-delivery of anticancer drug BER and miR-122 to significantly increase the anticancer therapeutic effects.

MiR-122-5p inhibits cell migration and invasion in gastric cancer by down-regulating DUSP4

OBJECTIVE

To explore the relationship between miR-122-5p and DUSP4 and their effects on gastric cancer (GC) cell mobility and invasiveness.

METHODS

Abnormally expressed miRNAs and mRNAs were analyzed using microarrays. The miR-122-5p and DUSP4 mRNA expression levels in GC tissues and cells were determined by RT-qPCR. The target relationship between miR-122-5p and DUSP4 was validated by dual luciferase reporter assay. GC cell mobility and invasiveness were respectively observed by wound healing assay and transwell invasion assay. Western blot and immunohistochemistry were used for detection of the expressions of DUSP4 protein and MMP2 and MMP9 proteins related to cell invasion and migration. The migration and invasion abilities of gastric cancer cells in vivo were evaluated according to the number of lung metastatic nodules in mice.

RESULTS

The expression of miR-122-5p in GC tissues and cells was significantly down-regulated, whereas DUSP4 expression was up-regulated. Bioinformatics prediction strategies and dual luciferase reporter assay verified the binding sites of miR-122-5p on 3'UTR of DUSP4 and the target relationship between miR-122-5p and DUSP4. Overexpression of miR-122-5p and knockdown of DUSP4 in BGC-823 cells observantly suppressed GC cell mobility and invasiveness, whereas downregulation of miR-122-5p expression promoted cell metastasis. MiR-122-5p inhibited GC cell mobility and invasiveness and pulmonary tumor metastasis via downregulation of DUSP4.

CONCLUSION

MiR-122-5p restrained migration and invasion abilities of GC cells by repressing DUSP4.

miR-223 increases gallbladder cancer cell sensitivity to docetaxel by downregulating STMN1

Background

MicroRNAs (miRs) are involved in cancer carcinogenesis, and certain regulatory miRs could provide promising therapeutic methods for refractory malignancies, such as gallbladder cancer (GBC). miR-223 was found to play a pivotal role in enhancing chemotherapeutic effects, therefore evoking interest in the role of miR-223 in GBC.

Results

miR-223 was decreased in GBC tissues and cell lines, and ectopic miR- 223 expression exhibited multiple anti-tumorigenic effects in GBC cells, including decreased proliferation, migration and invasion in vitro. However, treatment with a miR-223 inhibitor increased cell viability. We determined that STMN1 was negatively correlated with and regulated by miR-223 in GBC. miR-223 increased GBC sensitivity to docetaxel in vitro and in vivo, and the induced sensitivity to docetaxel was suppressed by the restoration of STMN1 expression.

Methods

We examined miR-223 expression in GBC tissue and GBC cell lines using qRT-PCR. The effects of modulated miR-223 expression in GBC cells were assayed using Cell Counting Kit-8 (CCK8), flow cytometry, and wound-healing and invasion assays. Susceptibility to docetaxel was evaluated in miR-223/STMN1-modulated GBC cells and xenograft tumor models. The protein expression of relevant genes was examined by Western blotting.

Conclusions

These findings indicated that miR-223 might serve as an onco-suppressor that enhances susceptibility to docetaxel by downregulating STMN1 in GBC, highlighting its promising therapeutic value.

Characterization and selective incorporation of small non-coding RNAs in non-small cell lung cancer extracellular vesicles

Background

Extracellular vesicles (EVs) play important roles in intercellular communication through the delivery of their cargoes, which include proteins, lipids, and RNAs. Increasingly, multiple studies have reported the association between EV small non-coding RNAs and cancer, due to their regulatory functions in gene expression. Hence, analysis of the features of small non-coding RNA expression and their incorporation into EVs is important for cancer research.

Results

We performed deep sequencing to investigate the expression of small RNAs in plasma EVs from lung adenocarcinoma (ADC) patients, lung squamous cell carcinoma (SQCC) patients, and healthy controls. Then, eighteen differently expressed miRNAs in plasma EVs was validated by QRT-PCR. The small RNA expression profiles of plasma EVs were different among lung ADC, SQCC patients, and healthy controls. And many small RNAs, including 5′ YRNA hY4-derived fragments, miR-451a, miR-122-5p, miR-20a-5p, miR-20b-5p, miR-30b-5p, and miR-665, were significantly upregulated in non-small cell lung cancer (NSCLC) EVs. And the cell viability assays indicated that hY4-derived fragments inhibited the proliferation of lung cancer cell A549. By comparing the cellular and EV expression levels of six miRNAs in NSCLC cells, we found that miR-451a and miR-122-5p were significantly downregulated in NSCLC cell lysates, while significantly upregulated in NSCLC EVs.

Conclusions

The differently expressed EV small RNAs may serve as potential circulating biomarkers for the diagnosis of NSCLC. Particularly, YRNA hY4-derived fragments can serve as a novel class of biomarkers, which function as tumor suppressors in NSCLC. Additionally, miR-451a and miR-122-5p may be sorted into NSCLC EVs in a selective manner.

Electronic supplementary material

The online version of this article (10.1186/s13578-018-0202-x) contains supplementary material, which is available to authorized users.

Epithelial-to-mesenchymal transition in gallbladder cancer: from clinical evidence to cellular regulatory networks

Gallbladder cancer (GBC), with late diagnosis, rapid disease progression and early metastasis, is a highly aggressive malignant tumor found worldwide. Patients with GBC have poor survival, low curative resection rates and early recurrence. For such a lethal tumor, uncovering the mechanisms and exploring new strategies to prevent tumor progression and metastasis are critically important. Epithelial-to-mesenchymal transition (EMT) has a prominent role in the early steps of tumor progression and metastasis by initiating polarized epithelial cell transition into motile mesenchymal cells. Accumulating evidence suggests that EMT can be modulated by the cooperation of multiple mechanisms affecting common targets. Signaling pathways, transcriptional and post-transcriptional regulation and epigenetic alterations are involved in the stepwise EMT regulatory network in GBC. Loss of epithelial markers, acquisition of mesenchymal markers and dysregulation of EMT-inducing transcription factors (EMT-TFs) have been observed and are associated with the clinicopathology and prognosis of GBC patients. Therefore, EMT may be a detectable and predictable event for predicting GBC progression and metastasis in the clinic. In this review, we will provide an overview of EMT from the clinical evidence to cellular regulatory networks that have been studied thus far in clinical and basic GBC studies.

Knockdown of LncRNA ANRIL suppresses cell proliferation, metastasis, and invasion via regulating miR-122-5p expression in hepatocellular carcinoma

OBJECTIVE

Previous studies reported that lncRNA antisense non-coding RNA in the INK4 locus (ANRIL) was upregulated in hepatocellular carcinoma (HCC) tissues and decreased expression of ANRIL could suppress cell proliferation, metastasis, and invasion and induce apoptosis of HCC cells. However, the molecular mechanism of ANRIL involved in HCC tumorigenesis is still unknown.

METHODS

The expressions of ANRIL and miR-122-5p in HCC tissues and cells were quantified by qRT-PCR. MTT assay, colony formation assay, wound healing assay, and transwell invasion assay were performed to evaluate cell growth, metastasis, and invasion, respectively. RNA immunoprecipitation (RIP) assay and luciferase reporter assay were performed to determine whether ANRIL could directly bind to miR-122-5p in HCC cells. Xenograft tumor experiment was conducted to confirm the biological role and underlying mechanism of ANRIL in vivo.

RESULTS

The results showed that ANRIL was upregulated and miR-122-5p was downregulated in HCC tissues and cells. ANRIL was negatively correlated with miR-122-5p expression in HCC tissues. Knockdown of ANRIL or miR-122-5p overexpression suppressed HCC cell viability, colony formation ability, metastasis, and invasion. ANRIL was demonstrated to directly bind to miR-122-5p and inhibit its expression. Forced expression of ANRIL abolished the inhibitory effect of miR-122-5p overexpression on HCC progression. In vivo experiment demonstrated that ANRIL knockdown impeded tumor growth in vivo and increased miR-122-5p expression.

CONCLUSION

Our finding suggested that knockdown of ANRIL suppressed cell proliferation, metastasis and invasion via regulating miR-122-5p expression in HCC, illustrating the underlying mechanism of the oncogenic role of ANRIL in HCC.

Resveratrol Induces Cancer Cell Apoptosis through MiR-326/PKM2-Mediated ER Stress and Mitochondrial Fission

Resveratrol (Res), a natural phytoalexin found in a variety of plants, has significant antitumor activity. Pyruvate kinase M2 (PKM2) has abnormally high expression in various tumor cells, and it has been implicated in the survival of tumors. However, whether and how Res inhibits PKM2 expression is poorly understood. In the present study, we found that treatment with Res inhibited cell proliferation and induced cell apoptosis. The IC50 values of Res against DLD1, HeLa, and MCF-7 cells were 75 ± 4.54, 50 ± 3.65, and 50 ± 3.32 μM, respectively. To elucidate mechanisms underlying its antitumor activities, serial experiments were performed. Results showed that reduction of PKM2 expression in tumor cells by Res treatment increased the expression of ER stress and mitochondrial fission proteins but reduced cell viability and the levels of fusion proteins. These phenomena were reversed by artificial overexpression of PKM2. Quantitative analyses showed that the expression of microRNA-326 (miR-326) was increased upon Res treatment. Treatment with the miR-326 mimic reduced PKM2 expression, promoting recovery from ER stress and mitochondrial fission. Overall, these results demonstrate that miR-326/PKM2-mediated ER stress and mitochondrial dysfunction participate in apoptosis induced by Res. These results provide novel insight into the molecular mechanisms by which Res suppresses tumors and further support for the use of Res as an antitumor drug.

Deregulated MicroRNAs in Biliary Tract Cancer: Functional Targets and Potential Biomarkers

Biliary tract cancer (BTC) is still a fatal disease with very poor prognosis. The lack of reliable biomarkers for early diagnosis and of effective therapeutic targets is a major demanding problem in diagnosis and management of BTC. Due to the clinically silent and asymptomatic characteristics of the tumor, most patients are diagnosed at an already advanced stage allowing only for a palliative therapeutic approach. MicroRNAs are small noncoding RNAs well known to regulate various cellular functions and pathologic events including the formation and progression of cancer. Over the last years, several studies have shed light on the role of microRNAs in BTC, making them potentially attractive therapeutic targets and candidates as biomarkers. In this review, we will focus on the role of oncogenic and tumor suppressor microRNAs and their direct targets in BTC. Furthermore, we summarize and discuss data that evaluate the diagnostic power of deregulated microRNAs as possible future biomarkers for BTC.

Pyruvate Kinase M2: A Potential Target for Regulating Inflammation

Pyruvate kinase (PK) is the enzyme responsible for catalyzing the last step of glycolysis. Of the four PK isoforms expressed in mammalian cells, PKM2 has generated the most interest due to its impact on changes in cellular metabolism observed in cancer as well as in activated immune cells. As our understanding of dysregulated metabolism in cancer develops, and in light of the growing field of immunometabolism, intense efforts are in place to define the mechanism by which PKM2 regulates the metabolic profile of cancer as well as of immune cells. The enzymatic activity of PKM2 is heavily regulated by endogenous allosteric effectors as well as by intracellular signaling pathways, affecting both the enzymatic activity of PKM2 as a PK and the regulation of the recently described non-canonical nuclear functions of PKM2. We here review the current literature on PKM2 and its regulation, and discuss the potential for this protein as a therapeutic target in inflammatory disorders.