MiR-27b suppresses epithelial-mesenchymal transition and chemoresistance in lung cancer by targeting Snail1

Non-coding RNAs and exosomal non-coding RNAs in lung cancer: insights into their functions

Lung cancer is the second most common form of cancer worldwide Research points to the pivotal role of non-coding RNAs (ncRNAs) in controlling and managing the pathology by controlling essential pathways. ncRNAs have all been identified as being either up- or downregulated among individuals suffering from lung cancer thus hinting that they may play a role in either promoting or suppressing the spread of the disease. Several ncRNAs could be effective non-invasive biomarkers to diagnose or even serve as effective treatment options for those with lung cancer, and several molecules have emerged as potential targets of interest. Given that ncRNAs are contained in exosomes and are implicated in the development and progression of the malady. Herein, we have summarized the role of ncRNAs in lung cancer. Moreover, we highlight the role of exosomal ncRNAs in lung cancer.

Regulation and therapeutic potentials of microRNAs to non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, accounting for 80%-85% of total cases and leading to millions of deaths worldwide. Drug resistance is the primary cause of treatment failure in NSCLC, which urges scientists to develop advanced approaches for NSCLC treatment. Among novel approaches, the miRNA-based method has emerged as a potential approach as it allows researchers to modulate target gene expression. Subsequently, cell behaviors are altered, which leads to the death and the depletion of cancer cells. It has been reported that miRNAs possess the capacity to regulate multiple genes that are involved in various signaling pathways, including the phosphoinositide 3-kinase, receptor tyrosine kinase/rat sarcoma virus/mitogen-activated protein kinase, wingless/integrated, retinoblastoma, p53, transforming growth factor β, and nuclear factor-kappa B pathways. Dysregulation of these signaling pathways in NSCLC results in abnormal cell proliferation, tissue invasion, and drug resistance while inhibiting apoptosis. Thus, understanding the roles of miRNAs in regulating these signaling pathways may enable the development of novel NSCLC treatment therapies. However, a comprehensive review of potential miRNAs in NSCLC treatment has been lacking. Therefore, this review aims to fill the gap by summarizing the up-to-date information on miRNAs regarding their targets, impact on cancer-associated pathways, and prospective outcomes in treating NSCLC. We also discuss current technologies for delivering miRNAs to the target cells, including virus-based, non-viral, and emerging extracellular vesicle-based delivery systems. This knowledge will support future studies to develop an innovative miRNA-based therapy and select a suitable carrier to treat NSCLC effectively.

Circ_0110498 facilitates the cisplatin resistance of non-small cell lung cancer by mediating the miR-1287-5p/RBBP4 axis

BACKGROUND

Circular RNAs (circRNAs) play vital roles in non-small cell lung cancer (NSCLC) progression. Our research analyzed the role of circ_0110498 on the cisplatin (DDP) resistance of NSCLC.

METHODS

Cell glycolysis was analyzed by measuring glucose consumption and lactate production. Protein expression was determined by western blot analysis. The expression of circ_0110498, microRNA (miR)-1287-5p and RBBP4 was detected by RT-qPCR assay. Cell counting kit-8, colony formation and transwell assays, together with flow cytometry were conducted to analyze cell DDP resistance, proliferation, metastasis and apoptosis.

RESULTS

Circ_0110498 expression was elevated in DDP-resistant NSCLC tissues and cells. Circ_0110498 silencing not only suppressed the DDP resistance of NSCLC cells by inhibiting cell growth, metastasis and glycolysis, but also enhanced the DDP sensitivity of NSCLC tumors. MiR-1287-5p was sponged by circ_0110498, and its inhibitor also reversed the effect of circ_0110498 silencing on the DDP resistance of NSCLC cells. MiR-1287-5p interacted with RBBP4, and RBBP4 overexpression partly reversed the inhibitory effect of miR-1287-5p on the DDP resistance of NSCLC cells.

CONCLUSION

Circ_0110498 facilitated DDP resistance partly through mediating the miR-1287-5p/RBBP4 signaling in NSCLC.

Bone Marrow Mesenchymal Stem Cells (BMSCs) Retard the Aggressive Migrating and Invading Activity of Non-Small Cell Lung Cancer Cells

Non-small cell lung cancer (NSCLC) is a common malignancy worldwide. miR-119-3p is down regulated in many cancers. Nonetheless, the modulatory mechanism of bone marrow mesenchymal stem cells (BMSCs) in NSCLC is unclear. Our research aims to dissect the activity of BMSCs on NSCLC and underlying mechanisms. After isolation and identification, BMSCs were co-cultured with NSCLC cells, which were transfected with miR-119-3p mimics followed by analysis of expression of miR-119-3p and tumor aggressiveness-related proteins, cell invasion/migration and survival. A significantly reduced miR-119-3p level was found in NSCLC cell lines. miR-119-3p mimics inhibited the proliferative, migrating and invasive behaviors of NSCLC cells. Co-culture with BMSCs enhanced miR-119-3p expression in NSCLC cells, thereby suppressing NSCLC cell biological behaviors. Simultaneously, the EMT process was markedly restrained, as indicated by an elevated level of E-cadherin but diminished levels of Vimetnin, N-cadherin and Snail. In conclusion, BMSCs can interfere with the EMT process of NSCLC via up-regulatingmiR-119-3p, thereby retarding the aggressive migration and invasive capability of NSCLC cells.

MicroRNAs as Predictors of Lung-Cancer Resistance and Sensitivity to Cisplatin

Background: Platinum-based chemotherapy, cisplatin (DDP) specifically, is the main strategy for treating lung cancer (LC). However, currently, there is a lack of predictive drug-resistance markers, and there is increased interest in the development of a reliable and sensitive panels of markers for DDP chemotherapy-effectiveness prediction. MicroRNAs represent a perspective pool of markers for chemotherapy effectiveness. Objectives: Data on miRNAs associated with LC DDP chemotherapy response are summarized and analyzed. Materials and methods: A comprehensive review of the data in the literature and an analysis of bioinformatics resources were performed. The gene targets of miRNAs, as well as their reciprocal relationships with miRNAs, were studied using several databases. Results and Discussion: The complex analysis of bioinformatics resources and the literature indicated that the expressions of 12 miRNAs have a high predictive potential for LC DDP chemotherapy responses. The obtained information was discussed from the point of view of the main mechanisms of LC chemoresistance. Conclusions: An overview of the published data and bioinformatics resources, with respect to the predictive microRNA markers of chemotherapy response, is presented in this review. The selected microRNAs and gene panel have a high potential for predicting LC DDP sensitiveness or DDP resistance as well as for the development of a DDP co-therapy.

MiRNAs in Lung Cancer: Diagnostic, Prognostic, and Therapeutic Potential

Lung cancer is the dominant emerging factor in cancer-related mortality around the globe. Therapeutic interventions for lung cancer are not up to par, mainly due to reoccurrence/relapse, chemoresistance, and late diagnosis. People are currently interested in miRNAs, which are small double-stranded (20–24 ribonucleotides) structures that regulate molecular targets (tumor suppressors, oncogenes) involved in tumorigeneses such as cell proliferation, apoptosis, metastasis, and angiogenesis via post-transcriptional regulation of mRNA. Many studies suggest the emerging role of miRNAs in lung cancer diagnostics, prognostics, and therapeutics. Therefore, it is necessary to intensely explore the miRNOME expression of lung tumors and the development of anti-cancer strategies. The current review focuses on the therapeutic, diagnostic, and prognostic potential of numerous miRNAs in lung cancer.

LINC01234 regulates microRNA-27b-5p to induce the migration, invasion and self-renewal of ovarian cancer stem cells through targeting SIRT5

LINC01234 has been suggested to correlate with the survival of ovarian cancer (OS), but its role in the properties of OC stem cells (OCSCs) has been rarely described. We aim to investigate the effect of LINC01234 on the differentiation and self-renewal of OCSCs through adsorption of microRNA (miR)-27b-5p to target sirtuins 5 (SIRT5). Expression of LINC01234 and SIRT5 in OC and normal samples included in TCGA and GTEx was searched through the GEPIA2 database. Bioinformatics analysis was conducted to predict the relation of LINC01234, miR-27b-5p and SIRT5. Expression of LINC01234, miR-27b-5p and SIRT5 in OC tissues and cells was detected. OCSCs were cultured and identified. CD133⁺ OCSCs were introduced with related oligonucleotides or vectors of LINC01234 or miR-27b-5p and SIRT5 to figure out their roles in OCSCs progression and tumorigenesis in vivo. The interaction of miR-27b-5p with LINC01234 or SIRT5 was analyzed. Bioinformatics analysis suggested that LINC01234 was very likely to influence SIRT5 and regulate the development of OC through miR-27b-5p. Up-regulated LINC01234 exhibited in OC tissues and cells. Down-regulated LINC01234 or elevated miR-27b-5p suppressed OCSCs progression and tumorigenesis in vivo. LINC01234 could restore SIRT5 expression by binding to miR-27b-5p. Down-regulated miR-27b-5p reversed the effect of silenced LINC01234 on OCSCs development and tumorigenesis in vivo. Up-regulation of SIRT5 reduced the effects of elevated miR-27b-5p on OCSCs progression and tumorigenesis in vivo. LINC01234 regulates miR-27b-5p to induce the migration, invasion and self-renewal of OCSCs through targeting SIRT5.

Low expression of miR-27b in serum exosomes of non-small cell lung cancer facilitates its progression by affecting EGFR

Non-small cell lung cancer (NSCLC) is a malignant tumor. Serum exosomal miR-27b is related to tumor diagnosis. We explored the roles of serum exosomal miR-27b in NSCLC. NSCLC patients were assigned to NSCLC-early/terminal groups, with healthy subjects as controls. miR-27b expression was assessed using reverse transcription-quantitative polymerase chain reaction, and its diagnostic efficiency was analyzed using the receiver operating characteristic curve. The correlation between serum exosomal miR-27b expression and tumor markers carcinoembryonic antigen 125 (CA125), carcinoembryonic antigen (CEA), and cytokeratin 19-soluble fragment (CYFRA21-1) was analyzed using the Pearson analysis. The downstream target genes were predicted. Epidermal growth factor receptor (EGFR) level was assessed using enzyme-linked immunosorbent assay. Correlations of miR-27b expression with serum EGFR level and CA125, CEA, and CYFRA21-1 levels were analyzed using the Pearson analysis. Serum exosomal miR-27b was diminished in NSCLC and was further decreased in the NSCLS-terminal group. The sensitivity of miR-27b < 0.8150 for NSCLC diagnosis was 76.64%, and the specificity was 83.33%. Serum exosomal miR-27b was negatively correlated with CA125, CEA, and CYFRA21-1. miR-27b targeted EGFR. Serum EGFR was raised in NSCLC and was further elevated in the NSCLS-terminal group. miR-27b expression was negatively correlated with EGFR level. EGFR level was positively correlated with CA125, CEA, and CYFRA21-1 levels. Collectively, low expression of miR-27b assisted NSCLC diagnosis, and miR-27b exerted effects on NSCLC through EGFR.

LncRNA DNAJC3-AS1 Promotes Hepatocellular Carcinoma (HCC) Progression via Sponging Premature miR-27b

Purpose

Long non-coding RNA (lncRNA) DNAJC3 antisense RNA 1 (head to head) (DNAJC3-AS1) plays a key role in the progression of several cancers. However, its biological role in hepatocellular carcinoma (HCC) is still unclear. We aimed to investigate the role of DNAJC3-AS1 in the development of HCC and reveal the potential mechanisms.

Materials and Methods

Expression analysis of DNAJC3-AS1 and microRNA-27b (miR-27b) at both mature and premature levels was determined by RT-qPCR. HCC patients were followed up for 5 years to analyze the prognostic value of DNAJC3-AS1 for HCC. The direct interaction between DNAJC3-AS1 and premature miR-27b was analyzed with RNA pull-down assay. Subcellular analysis of DNAJC3-AS1 was explored by subcellular fractionation assay. DNAJC3-AS1 overexpression and knockdown were carried out to analyze the role of DNAJC3-AS1 in miR-27b maturation. Cell proliferation was analyzed by BrdU assay.

Results

DNAJC3-AS1 was overexpressed in HCC and predicts the poor survival. MiR-27b was downregulated at mature miRNA level, but upregulated at premature level. DNAJC3-AS1 directly interacted with premature miR-27b and was localized to both nuclear and cytoplasm. DNAJC3-AS1 overexpression upregulated premature miR-27b and downregulated mature miR-27b, while DNAJC3-AS1 knockdown led to the opposite results. DNAJC3-AS1 suppressed the role of miR-27b in inhibiting cell proliferation.

Conclusion

DNAJC3-AS1 promotes HCC by sponging premature miR-27b and might be a biomarker and therapeutic target for HCC.

Therapeutic approaches targeting molecular signaling pathways common to diabetes, lung diseases and cancer

Diabetes mellitus (DM), is the most common metabolic disease and is characterized by sustained hyperglycemia. Accumulating evidences supports a strong association between DM and numerous lung diseases including chronic obstructive pulmonary disease (COPD), fibrosis, and lung cancer (LC). The global incidence of DM-associated lung disorders is rising and several ongoing studies, including clinical trials, aim to elucidate the molecular mechanisms linking DM with lung disorders, in particular LC. Several potential mechanisms, including hyperglycemia, hyperinsulinemia, glycation, inflammation, and hypoxia, are cited as plausible links between DM and LC. In addition, studies also propose a connection between the use of anti-diabetic medications and reduction in the incidence of LC. However, the exact cause for DM associated lung diseases especially LC is not clear and is an area under intense investigation. Herein, we review the biological links reported between DM and lung disorders with an emphasis on LC. Furthermore, we report common signaling pathways (eg: TGF-β, IL-6, HIF-1, PDGF) and miRNAs that are dysregulated in DM and LC and serve as molecular targets for therapy. Finally, we propose a nanomedicine based approach for delivering therapeutics (eg: IL-24 plasmid DNA, HuR siRNA) to disrupt signaling pathways common to DM and LC and thus potentially treat DM-associated LC. Finally, we conclude that the effective modulation of commonly regulated signaling pathways would help design novel therapeutic protocols for treating DM patients diagnosed with LC.

Molecular mechanism involved in epithelial to mesenchymal transition

Epithelial to mesenchymal transition (EMT) is a biological process that plays an important role during embryonic development. During this process, the epithelial cells lose their polarity and acquire mesenchymal properties. In addition to embryonic development, EMT is also well-known to participate in tissue repair, inflammation, fibrosis, and tumor metastasis. In the present review, we address the basics of epithelial to mesenchymal transition during both development and disease conditions and emphasize the role of various transcription factors and miRNAs involved in the process.

Transcription factor PAX4 facilitates gastric cancer progression through interacting with miR-27b-3p/Grb2 axis

Gastric cancer (GC) is one of the most common aggressive cancers. The discovery of an effective biomarker is necessary for GC diagnosis. In this study, we confirmed that Paired box gene 4 (PAX4) is up-regulated in GC tissues and cells via quantitative real time polymerase chain reaction (qRT-PCR), western blot and immunohistochemical staining. It was also identified that PAX4 contributed to GC cell proliferation, migration and invasion through Cell Counting Kit-8, BrdU, flow cytometry assay, colony formation assay, transwell assays, and wound healing assay. miR-27b-3p was confirmed with the binding site with PAX4 using ChIP assay and served as a tumor suppressor that inhibiting GC cell growth and metastasis, and reversed the effect of PAX4. Bioinformatics prediction and dual luciferase assay results demonstrated that miR-27b-3p targeted Grb2, which could alter the function of miR-27b-3p. Furthermore, the transcriptional control of PAX4-regulated miR-27b-3p activated the Ras-ERK pathway. Taken together, the PAX4/miR-27b-3p/Grb2 loop is known to be involved in GC cell promotion, and can be seen as a promising target for GC therapy.

Genomic Characterization of Cisplatin Response Uncovers Priming of Cisplatin-Induced Genes in a Resistant Cell Line

Cisplatin is a chemotherapy drug that kills cancer cells by damaging their DNA. In human cells, this damage is repaired primarily by nucleotide excision repair. While cisplatin is generally effective, many cancers exhibit initial or acquired resistance to it. Here, we studied cisplatin resistance in a defined cell line system. We conducted a comprehensive genomic characterization of the cisplatin-sensitive A2780 ovarian cancer cell line compared to A2780cis, its resistant derivative. The resistant cells acquired less damage, but had similar repair kinetics. Genome-wide mapping of nucleotide excision repair showed a shift in the resistant cells from global genome towards transcription-coupled repair. By mapping gene expression changes following cisplatin treatment, we identified 56 upregulated genes that have higher basal expression in the resistant cell line, suggesting they are primed for a cisplatin response. More than half of these genes are novel to cisplatin- or damage-response. Six out of seven primed genes tested were upregulated in response to cisplatin in additional cell lines, making them attractive candidates for future investigation. These novel candidates for cisplatin resistance could prove to be important prognostic markers or targets for tailored combined therapy in the future.

Interplay between SOX9 transcription factor and microRNAs in cancer

SOX transcription factors are critical regulators of development, homeostasis and disease progression and their dysregulation is a common finding in various cancers. SOX9 belongs to SOXE family located on chromosome 17. MicroRNAs (miRNAs) possess the capacity of regulating different transcription factors in cancer cells by binding to 3'-UTR. Since miRNAs can affect differentiation, migration, proliferation and other physiological mechanisms, disturbances in their expression have been associated with cancer development. In this review, we evaluate the relationship between miRNAs and SOX9 in different cancers to reveal how this interaction can affect proliferation, metastasis and therapy response of cancer cells. The tumor-suppressor miRNAs can decrease the expression of SOX9 by binding to the 3'-UTR of mRNAs. Furthermore, the expression of downstream targets of SOX9, such as c-Myc, Wnt, PI3K/Akt can be affected by miRNAs. It is noteworthy that other non-coding RNAs including lncRNAs and circRNAs regulate miRNA/SOX9 expression to promote/inhibit cancer progression and malignancy. The pre-clinical findings can be applied as biomarkers for diagnosis and prognosis of cancer patients.

miR-371b-5p promotes cell proliferation, migration and invasion in non-small cell lung cancer via SCAI

Objective: Multiple gene targets have been reported for treatment of non-small cell lung cancer (NSCLC), however, the accompanying genetic tolerance was reported increasingly. Therefore, it is important to find new biomarkers or therapeutic targets in treatment of NSCLC.

Methods: The expression levels of miR-371b-5p were detected by qRT-PCR in NSCLC tissues and cell lines. To evaluate the effect of miR-371b-5p on NSCLC progression, we first transfected the miR-371b-5p inhibitor for construction of the miR-371b-5p down-regulated cell model. Then the cell proliferation, migration, invasion and cell apoptosis were detected. In addition, the expression levels of adhesion factors were detected. The target gene of miR-371b-5p was identified by bioinformatics analysis, and rescue experiment was conducted to validate the effect of miR-371b-5p on proliferation, migration and invasion of NSCLC.

Results: Our findings revealed that the miR-371b-5p was overexpressed in NSCLC and could markedly promote the cell proliferation, migration and invasion. Expression levels of both intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were significantly down-regulated when treated by miR-371b-5p inhibitor. Moreover, dual-luciferase reporter assay showed that the miR-371b-5p targeted SCAI in regulation of cell proliferation, migration and invasion, and the expression of miR-371b-5p was negatively associated with SCAI in NSCLC tissues and cell lines. Rescue experiment revealed that the miR-371b-5p could rescue the effect of SCAI on cell proliferation, migration and invasion.

Conclusion: Our results suggest that the miR-371b-5p and SCAI may serve as novel prognostic biomarkers and therapeutic targets for NSCLC.

A KRAS-responsive long non-coding RNA controls microRNA processing

Wild-type KRAS (KRASWT) amplification has been shown to be a secondary means of KRAS activation in cancer and associated with poor survival. Nevertheless, the precise role of KRASWT overexpression in lung cancer progression is largely unexplored. Here, we identify and characterize a KRAS-responsive lncRNA, KIMAT1 (ENSG00000228709) and show that it correlates with KRAS levels both in cell lines and in lung cancer specimens. Mechanistically, KIMAT1 is a MYC target and drives lung tumorigenesis by promoting the processing of oncogenic microRNAs (miRNAs) through DHX9 and NPM1 stabilization while halting the biogenesis of miRNAs with tumor suppressor function via MYC-dependent silencing of p21, a component of the Microprocessor Complex. KIMAT1 knockdown suppresses not only KRAS expression but also KRAS downstream signaling, thereby arresting lung cancer growth in vitro and in vivo. Taken together, this study uncovers a role for KIMAT1 in maintaining a positive feedback loop that sustains KRAS signaling during lung cancer progression and provides a proof of principle that interfering with KIMAT1 could be a strategy to hamper KRAS-induced tumorigenesis.

Small in Size, but Large in Action: microRNAs as Potential Modulators of PTEN in Breast and Lung Cancers

MicroRNAs (miRNAs) are well-known regulators of biological mechanisms with a small size of 19–24 nucleotides and a single-stranded structure. miRNA dysregulation occurs in cancer progression. miRNAs can function as tumor-suppressing or tumor-promoting factors in cancer via regulating molecular pathways. Breast and lung cancers are two malignant thoracic tumors in which the abnormal expression of miRNAs plays a significant role in their development. Phosphatase and tensin homolog (PTEN) is a tumor-suppressor factor that is capable of suppressing the growth, viability, and metastasis of cancer cells via downregulating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling. PTEN downregulation occurs in lung and breast cancers to promote PI3K/Akt expression, leading to uncontrolled proliferation, metastasis, and their resistance to chemotherapy and radiotherapy. miRNAs as upstream mediators of PTEN can dually induce/inhibit PTEN signaling in affecting the malignant behavior of lung and breast cancer cells. Furthermore, long non-coding RNAs and circular RNAs can regulate the miRNA/PTEN axis in lung and breast cancer cells. It seems that anti-tumor compounds such as baicalein, propofol, and curcumin can induce PTEN upregulation by affecting miRNAs in suppressing breast and lung cancer progression. These topics are discussed in the current review with a focus on molecular pathways.

miR-29b restrains cholangiocarcinoma progression by relieving DNMT3B-mediated repression of CDKN2B expression

Numerous studies have reported the important role of microRNAs (miRNAs) in human cancers. Although abnormal miR-29b expression has been linked to tumorigenesis in several cancers, its role in cholangiocarcinoma remains largely unknown. We found that miR-29b expression is frequently downregulated in human cholangiocarcinoma QBC939 cells and in clinical tumor samples. In cholangiocarcinoma patients, low miR-29b expression predicts poor overall survival. Overexpression of miR-29b in QBC939 cells inhibited proliferation, induced G1 phase cycle arrest, and promoted apoptosis. Methylation-specific PCR (MSP) analysis revealed a decreased methylation imprint at the promoter of the cell cycle inhibitor gene CDKN2B in cells overexpressing miR-29b. After identifying the DNA methyltransferase DNMT3B as a putative miR-29b target, luciferase reporter assays confirmed a suppressive effect of miR-29b on DNMT3B expression. Accordingly, we detected an inverse correlation between miR-29b and DNMT3B expression in clinical cholangiocarcinoma specimens. In QBC939 cells, DNMT3B overexpression promoted proliferation and inhibited apoptosis. DNMT3B silencing, in turn, led to increased CDKN2B expression. We also observed significant growth arrest in subcutaneous tumors formed in nude mice by QBC939 cells overexpressing miR-29b. These findings suggest miR-29b functions as a tumor suppressor in cholangiocarcinoma by relieving DNMT3B-mediated repression of CDKN2B expression.

MiRNA-mediated EMT and CSCs in cancer chemoresistance

Cancer stem cells (CSCs) are a small group of cancer cells, which contribute to tumorigenesis and cancer progression. Cancer cells undergoing epithelial-to-mesenchymal transition (EMT) acquire the chemoresistant ability, which is regarded as an important feature of CSCs. Thus, there emerges an opinion that the generation of CSCs is considered to be driven by EMT. In this complex process, microRNAs (miRNAs) are found to play a key role. In order to overcome the drug resistance, inhibiting EMT as well as CSCs phenotype seem feasible. Thereinto, regulating the EMT- or CSCs-associated miRNAs is a crucial approach. Herein, we conduct this review to elaborate on the complicated interplay between EMT and CSCs in cancer chemoresistance, which is modulated by miRNAs. In addition, we elucidate the therapeutic strategy to overcome drug resistance through targeting EMT and CSCs.

Potential Role of miRNAs in the Acquisition of Chemoresistance in Neuroblastoma

Neuroblastoma (NB) accounts for about 8–10% of pediatric cancers, and the main causes of death are the presence of metastases and the acquisition of chemoresistance. Metastatic NB is characterized by MYCN amplification that correlates with changes in the expression of miRNAs, which are small non-coding RNA sequences, playing a crucial role in NB development and chemoresistance. In the present study, miRNA expression was analyzed in two human MYCN-amplified NB cell lines, one sensitive (HTLA-230) and one resistant to Etoposide (ER-HTLA), by microarray and RT-qPCR techniques. These analyses showed that miRNA-15a, -16-1, -19b, -218, and -338 were down-regulated in ER-HTLA cells. In order to validate the presence of this down-regulation in vivo, the expression of these miRNAs was analyzed in primary tumors, metastases, and bone marrow of therapy responder and non-responder pediatric patients. Principal component analysis data showed that the expression of miRNA-19b, -218, and -338 influenced metastases, and that the expression levels of all miRNAs analyzed were higher in therapy responders in respect to non-responders. Collectively, these findings suggest that these miRNAs might be involved in the regulation of the drug response, and could be employed for therapeutic purposes.

Lung cancer cells and their sensitivity/resistance to cisplatin chemotherapy: Role of microRNAs and upstream mediators

Cisplatin (CP) is a well-known chemotherapeutic agent with excellent clinical effects. The anti-tumor activity of CP has been demonstrated in different cancers such as breast, cervical, reproductive, lung, brain, and prostate cancers. However, resistance of cancer cells to CP chemotherapy has led to its failure in eradication of cancer cells, and subsequent death of patients with cancer. Fortunately, much effort has been put to identify molecular pathways and mechanisms involved in CP resistance/sensitivity. It seems that microRNAs (miRs) are promising candidates in mediating CP resistance/sensitivity, since they participate in different biological aspects of cells such as proliferation, migration, angiogenesis, and differentiation. In this review, we focus on miRs and their regulation in CP chemotherapy of lung cancer, as the most malignant tumor worldwide. Oncogenic miRs trigger CP resistance in lung cancer cells via targeting various pathways such as Wnt/β-catenin, Rab6, CASP2, PTEN, and Apaf-1. In contrast, onco-suppressor miRs inhibit oncogene pathways such as STAT3 to suppress CP resistance. These topics are discussed to determine the role of miRs in CP resistance/sensitivity. We also describe the upstream modulators of miRs such as lncRNAs, circRNAs, NF-κB, SOX2 and TRIM65 and their association with CP resistance/sensitivity in lung cancer cells. Finally, the effect of anti-tumor plant-derived natural compounds on miR expression during CP sensitivity of lung cancer cells is discussed.

Stabilization of snail maintains the sorafenib resistance of hepatocellular carcinoma cells

Drug resistance is one of the major challenges for treatment of hepatocellular carcinoma (HCC) with sorafenib. Our present study found that sorafenib resistant (SR) HCC cells showed epithelial-mesenchymal transition (EMT) characteristics with the downregulation of epithelial marker and upregulation of mesenchymal makers. The expression of Snail, a core factor of EMT, was increased in HCC/SR cells, while knockdown of Snail can restore sorafenib sensitivity and EMT potential of HCC/SR cells. Further, the upregulation of protein stability was responsible for the upregulation of Snail in HCC/SR cells. ATM and CSN2, which can stabilize Snail protein, were increased in HCC/SR cells. Knockdown of ATM and CSN2 can suppress the expression of Snail and increase sorafenib sensitivity of HCC/SR cells. It indicated that targeted inhibition of Snail might be helpful to overcome sorafenib resistance of HCC patients.

miR-30d-5p suppresses proliferation and autophagy by targeting ATG5 in renal cell carcinoma

Previous reports have shown that miR-30d-5p functions as a tumor suppressor in prostate cancer and gallbladder carcinoma, but its role in renal cell carcinoma (RCC) remains elusive. This study was designed to explore the functional role of miR-30d-5p in proliferation and autophagy of RCC. Our results show that miR-30d-5p is significantly down-regulated in RCC tissues compared with normal tissues. miR-30d-5p overexpression suppressed cell proliferation, cell-cycle G1/S transition and autophagy, but promoted apoptosis in RCC cell lines (786-O and ACHN). Intriguingly, autophagy-related gene 5 (ATG5) was directly targeted by miR-30d-5p, as shown using luciferase reporter assay and biotin-avidin pull-down assay. Moreover, overexpression of ATG5 attenuated the inhibitory effect of miR-30d-5p on proliferation and autophagy in 786-O cells. These results suggest that miR-30d-5p suppresses proliferation and autophagy in RCC cells by targeting ATG5, and this pathway may be a suitable basis for the design of novel cancer therapeutics.

miR-27b Suppresses Tongue Squamous Cell Carcinoma Epithelial-Mesenchymal Transition by Targeting ITGA5

BACKGROUND

MicroRNA27b-3p (miR-27b) has been reported to be dysregulated in multiple types of human cancer. However, the expression levels, biological roles, and underlying mechanism of miR-27b in tongue squamous cell carcinoma (TSCC) remain to be elucidated.

METHODS

Bioinformatics analyses and quantitative real-time PCR (qRT-PCR) were used to determine miR-27b expression in TSCC tissues and cell lines. The influence of miR-27b overexpression or inhibition on TSCC cell proliferation, migration, and invasion in vitro, and on tumor growth in vivo, was explored via CCK8, colony formation, wound healing, and transwell assays, and in xenograft tumors in nude mice, respectively. Luciferase reporter assays, qRT-PCR, and Western blotting were performed to clarify the potential mechanisms involving miR-27b in TSCC cells.

RESULTS

miR-27b was significantly downregulated in TSCC tissues and cell lines, and its expression was correlated with cancer status. Overexpression of miR-27b led to diminished proliferation, migration, and invasion, and notably reduced tumor growth in vivo. Bioinformatics analysis followed by luciferase reporter assays demonstrated that miR-27b expression was inversely correlated with that of integrin subunit α5 (ITGA5)and that miR-27b directly bound to the 3'-untranslated region of ITGA5 in TSCC cells. The bioinformatics analysis also indicated that ITGA5 was upregulated in TSCC and that its expression was correlated with epithelial-mesenchymal transition (EMT) and poor prognosis. Moreover, we found that miRNA-27b could reverse ITGA5-induced promotion of TSCC cell proliferation and migration. Finally, we demonstrated that regulation of miR-27b expression in TSCC may result in alterations in the expression of ITGA5 and EMT-related marker genes at the mRNA and protein levels.

CONCLUSION

These results indicate that miR-27b hampers TSCC proliferation and migration via suppressing the EMT process by targeting ITGA5. These findings support consideration of miR-27b/ITGA5 as a valuable marker for the metastatic potential of TSCC, or as a therapeutic target for the treatment of TSCC.

MicroRNA-138-5p targets the NFIB-Snail1 axis to inhibit colorectal cancer cell migration and chemoresistance

Background

Colorectal cancer ranks among the most lethal diseases worldwide. Although much progress has been made in research and treatment of colorectal cancer in recent years, the underlying mechanisms related to migration of the cancer cells and the reason for chemoresistance still remain unclear. In this research, we explored the underlying effect of miR-138-5p in colorectal cancer.

Methods

We used qRT-PCR to investigate the expression of miR-138-5p, Snail1, NFIB in colorectal cancer cells. Lentiviral vectors containing miR-138-5p mimics and inhibitors were constructed and transfected cells. Wound healing assay was applied to illustrate interferences on cell migration. Fluorouracial, doxorubicin, cisplat in were used to detect chemotherapy resistance. In order to identify target genes, bioinformatic methods were applied. Snail1 and NFIB protein expression in stable cell lines was detected using Western blot. Double luciferase and CHIP experiment were used to verify binding sites. We used rescue experiments to further explore the interactions among Snail1, NFIB and miR-138-5p.

Results

The expression of miR-138-5p in colorectal cancer cells was low. miR-138-5p inhibited cell migration in colorectal cancer, and could negatively regulate chemotherapy resistance. miR-138-5p targeted NFIB, and regulated Snail1 expression, which mediated colorectal cancer cell migration and chemotherapy resistance.

Conclusions

Our research indicates that miR-138-5p could be a crucial modulator controlling colorectal cancer cell migration and chemoresistance, by acting upon the NFIB-Snail1 axis. miR-138-5p has an emerging prospect to be exploited as a new target for colorectal cancer.

High expression of SRY-box transcription factor 30 associates with well differentiation, absent lymph node metastasis and predicts longer survival in nonsmall-cell lung cancer patients

The present study aimed to investigate SRY-box transcription factor 30 (SOX30) expression in nonsmall-cell lung cancer (NSCLC) tumor tissues and adjacent noncancerous tissues, and further explore the correlation of tumor SOX30 expression with clinical characteristics and survival profiles in patients with NSCLC.Totally, 365 patients with NSCLC who underwent resection were screened, and SOX30 expression was detected in their tumor tissues and adjacent noncancerous tissues via immunohistochemistry (IHC) assay, which was assessed by a semiquantitative method considering the multiplying staining intensity score and staining density score. According to the tumor SOX30 expression, patients were categorized as tumor SOX30 low (IHC score ≤3) and high (IHC score 4-12) patients, the latter were further divided into tumor SOX30 high+ (IHC score 4-6), high++ (IHC score 7-9), and high+++ (IHC score 10-12) patients.SOX30 was downregulated in NSCLC tumor tissues compared with adjacent noncancerous tissues. Meanwhile, tumor SOX30 high expression associated with well differentiation, absent lymph node metastasis, decreased TNM stage, but did not associated with age, gender, history of smoke and drink, hypertension, hyperlipidemia, diabetes, tumor size, or carcinoembryonic antigen level. Both accumulating disease-free survival and overall survival were the longest in tumor SOX30 high+++ patients, followed by tumor SOX30 high++ patients, and tumor SOX30 high+ patients, and the shortest in tumor SOX30 low patients. Besides, tumor SOX30 high expression was an independent predictor for longer disease-free survival and overall survival.Tumor SOX30 exhibits the potential to be a novel biomarker for survival prediction of patients with NSCLC.