miR-21 downregulates the tumor suppressor P12 CDK2AP1 and stimulates cell proliferation and invasion

The deleted in oral cancer (DOC1 aka CDK2AP1) tumor suppressor gene is downregulated in oral squamous cell carcinoma by multiple microRNAs

Cyclin-dependent kinase 2-associated protein 1 (CDK2AP1; also known as deleted in oral cancer or DOC1) is a tumor suppressor gene known to play functional roles in both cell cycle regulation and in the epigenetic control of embryonic stem cell differentiation, the latter as a core subunit of the nucleosome remodeling and histone deacetylation (NuRD) complex. In the vast majority of oral squamous cell carcinomas (OSCC), expression of the CDK2AP1 protein is reduced or lost. Notwithstanding the latter (and the DOC1 acronym), mutations or deletions in its coding sequence are extremely rare. Accordingly, CDK2AP1 protein-deficient oral cancer cell lines express as much CDK2AP1 mRNA as proficient cell lines. Here, by combining in silico and in vitro approaches, and by taking advantage of patient-derived data and tumor material in the analysis of loss of CDK2AP1 expression, we identified a set of microRNAs, namely miR-21-5p, miR-23b-3p, miR-26b-5p, miR-93-5p, and miR-155-5p, which inhibit its translation in both cell lines and patient-derived OSCCs. Of note, no synergistic effects were observed of the different miRs on the CDK2AP1-3-UTR common target. We also developed a novel approach to the combined ISH/IF tissue microarray analysis to study the expression patterns of miRs and their target genes in the context of tumor architecture. Last, we show that CDK2AP1 loss, as the result of miRNA expression, correlates with overall survival, thus highlighting the clinical relevance of these processes for carcinomas of the oral cavity.

Pulsatilla vulgaris Inhibits Cancer Proliferation in Signaling Pathways of 12 Reporter Genes

This study aimed to examine if methanolic extracts of Pulsatilla vulgaris Mill. can inhibit HeLa cell proliferation through the modulation of cancer-related signaling pathways. The cytotoxicity and chemical composition of P. vulgaris leaves and root extracts were also determined. Research showed that root extract of P. vulgaris inhibited 12 signaling pathways in a cervical cancer cell line and the most potent activation inhibition was observed for MYC, Notch, Wnt, E2F, Ets, Stat3, Smad, Hdghog, AP-1, and NF-κB, at a concentration of 40 µg/mL. The methanolic extracts of P. vulgaris enhanced apoptotic death and deregulated cellular proliferation, differentiation, and progression toward the neoplastic phenotype by altering key signaling molecules required for cell cycle progression. This is the first study to report the influence of P. vulgaris on cancer signaling pathways. Additionally, our detailed phytochemical analysis of the methanolic extracts of P. vulgaris gives a conclusion that compounds, which strongly suppressed the growth and proliferation of HeLa cancer cells were mainly triterpenoid saponins accompanied by phenolic acids.

MicroRNA-21 induces cisplatin resistance in head and neck squamous cell carcinoma

Drug resistance, either intrinsic or acquired, can impair treatment effects and result in increased cell motility and death. MicroRNA-21 (miR-21), a proto-oncogene, may facilitate the development or maintenance of drug resistance in cancer cells. Restoring drug sensitivity can improve therapeutic strategies, a possibility that requires functional evaluation and mechanistic exploration. For miR-21 detection, matched tissue samples from 30 head and neck squamous cell carcinoma (HNSCC) patients and 8 head and neck cancer (HNC) cell lines were obtained. Reverse transcription-PCR to detect expression, MTT and clonogenic assays to evaluate cell proliferation, apoptosis assays, resazurin cell viability assays, western blot and luciferase reporter assays to detect protein expression, and flow cytometry to analyse the cell cycle were adopted. Compared to the corresponding normal control (NC) tissues, 25 cancer tissues had miR-21 upregulation among the 30 matched pair tissues (25/30, 83.8%); furthermore, among the 8 HNC cell lines, miR-21 expression that was notably upregulated in three: UPCI-4B, UMSCC-1, and UPCI-15B. In both the UMSCC-1 and UPCI-4B cell lines, the miR-21 mimic enhanced cell proliferation with reduced apoptosis and increased viability, whereas the miR-21 inhibitor resulted in the opposite effects (all P<0.001); additionally, miR-21 directly targeted the tumour suppressor phosphatase and tensin homologue (PTEN) and inhibited PTEN expression. Furthermore, the miR-21 mimic induced cisplatin resistance, while the miR-21 inhibitor restored cisplatin sensitivity. Overexpression of miR-21 can enhance cell proliferation, reduce apoptosis, and induce drug resistance by inhibiting PTEN expression. Targeting miR-21 may facilitate cancer diagnosis, restore drug sensitivity, and improve therapeutic effects.

Downregulation of FEM1C enhances metastasis and proliferation in colorectal cancer

Background

Feminization-1 (FEM-1) is considered a substrate recognition subunit of CUL2-RING E3 ubiquitin ligase complexes, which refers to sex determination by modulating TRA-1 stability in C. elegans. The function of mammalian orthologous gene of FEM-1 remains to be elucidated.

Methods

The expression of FEM1C in colorectal cancer (CRC) cells was interfered by small interference RNA (siRNA) transfection, and Cell counting kit-8 (CCK-8) assay, colony formation assay and transwell assay were performed. In order to estimate the function on metastasis, stable knockdown FEM1C cells were used to established liver and lung metastasis models. In addition, the expression of FEM1C in normal tissues, adenomas and tumor tissues were analyzed, and the relationship between FEM1C expression level and prognosis was analyzed by Kaplan-Meier method.

Results

Here, we report that the elimination of FEM1C, one of the members of FEM-1, significantly promoted the migration and invasion of colorectal cancer (CRC) cells in vitro and promoted liver and lung metastases in vivo. It also showed that the removal of FEM1C improved the proliferation ability of CRC cells. In particular, the cell shape changed from epithelial to fibroblast-like morphology. The tight cell monolayer was transformed into a dispersed distribution. Furthermore, it was demonstrated that FEM1C is down-regulated in tissues of CRC compared to normal tissues, and the high expression of FEM1C positively correlates with a good prognosis in patients with CRC. GSEA analysis showed that EMT signatures was enriched in FEM1C knockdown groups.

Conclusions

Down-regulation of FEM1C promotes proliferation and metastasis, and FEM1C may be a tumor suppressor in the development of CRC.

Computational study to evaluate the potency of phytochemicals in Boerhavia diffusa and the impact of point mutation on cyclin-dependent kinase 2-associated protein 1

A protein's function is closely related to its structural properties. Mutations can affect the functionality of a protein. Different cancer tissues have found disordered expression of the cyclin-dependent kinase 2-associated Protein 1 (CDK2AP1) gene. A protein molecule's conformational flexibility affects its interaction with phytochemicals and their biological partners at various levels. Boerhavia diffusa has been investigated most extensively for its medicinal activities like anticancer properties. It contains many bioactive compounds like Boeravinone A, Boeravinone B, Boeravinone C, Boeravinone D, Boeravinone E, Boeravinone F, Boeravinone G, Boeravinone H, Boeravinone I and Boeravinone J. We have studied to analyse the binding efficacy properties as well as essential dynamic behaviour, free energy landscape of both the native and mutant protein CDK2AP1 with bioactive compounds from Boerhavia diffusa plant extracts through computational approaches by homology modelling, docking and molecular dynamics simulation. From the molecular docking study, we found that. Boeravinone J have best binding affinity (-7.9 kcal/mol) towards the native protein of CDKAP1 compared to others phytochemicals. However, we found the binding energy for H23R and C105R (mutation point) -7.8 and -7.6 kcal/mol, respectively. A single minima energy point (from 100 ns molecular dynamics simulation study) was found in the H23R mutant with Boeravinone J complex suggested that minimum structural changes with less conformational mobility compared C105A mutant model.Communicated by Ramaswamy H. Sarma.

microRNAs deregulation in head and neck squamous cell carcinoma

Head and neck (HN) squamous cell carcinoma (SCC) is the eighth most common human cancer worldwide. Besides tobacco and alcohol consumption, genetic and epigenetic alterations play an important role in HNSCC occurrence and progression. microRNAs (miRNAs) are small noncoding RNAs that regulate cell cycle, proliferation, development, differentiation, and apoptosis by interfering in gene expression. Expression profiling of miRNAs showed that some miRNAs are upregulated or downregulated in tumor cells when compared with the normal cells. The present review focuses on the role of miRNAs deregulations in HNSCC, enrolled in risk, development, outcome, and therapy sensitivity. Moreover, the influence of single nucleotide variants in miRNAs target sites, miRNAs seed sites, and miRNAs-processing genes in HNSCC was also revised. Due to its potential for cancer diagnosis, progression, and as a therapeutic target, miRNAs may bring new perspectives in HNSCC understanding and therapy, especially for those patients with no or insufficient treatment options.

Identification of Prognosis Associated microRNAs in HNSCC Subtypes Based on TCGA Dataset

Background and Objectives: Head and Neck Squamous Cell Carcinoma (HNSCC) includes cancers from the oral cavity, larynx, and oropharynx and is the sixth-most common cancer worldwide. MicroRNAs are small non-coding RNAs for which altered expression has been demonstrated in pathological processes, such as cancer. The objective of our study was to evaluate the different expression profile in HNSCC subtypes and the prognostic value that one or several miRNAs may have. Materials and Methods: Data from The Cancer Genome Atlas Program-Head and Neck Squamous Cell Carcinoma (TCGA-HNSCC) patients were collected. Differential expression analysis was conducted by edge R-powered TCGAbiolinks R package specific function. Enrichment analysis was developed with Diana Tool miRPath 3.0. Kaplan-Meier survival estimators were used, followed by log-rank tests to compute significance. Results: A total of 127 miRNAs were identified with differential expression level in HNSCC; 48 of them were site-specific and, surprisingly, only miR-383 showed a similar deregulation in all locations studied (tonsil, mouth, floor of mouth, cheek mucosa, lip, tongue, and base of tongue). The most probable affected pathways based on miRNAs interaction levels were protein processing in endoplasmic reticulum, proteoglycans in cancer (p < 0.01), Hippo signaling pathway (p < 0.01), and Transforming growth factor-beta (TGF-beta) signaling pathway (p < 0.01). The survival analysis highlighted 38 differentially expressed miRNAs as prognostic biomarkers. The miRNAs with a greater association between poor prognosis and altered expression (p < 0.001) were miR-137, miR-125b-2, miR-26c, and miR-1304. Conclusions: In this study we have determined miR-137, miR-125b-2, miR-26c, and miR-1304 as novel powerful prognosis biomarkers. Furthermore, we have depicted the miRNAs expression patterns in tumor patients compared with normal subjects using the TCGA-HNSCC cohort.

MicroRNAs in oral cancer: Biomarkers with clinical potential

Oral cancer is the sixteenth most common cancer globally, with a relatively poor five-year survival rate of 50%. Thus it is imperative to understand the biology of oral cancer and examine alternative prognostic and therapeutic targets for oral cancer. MicroRNAs (miRNAs) are small non-coding RNAs mediating gene expression at the post-transcriptional level through mRNA degradation or translational repression. miRNAs play an essential role in cancer development and oncogenic cell processes. miRNA deregulation is observed in oral cancer and associated with prognosis. However, the role of miRNAs and their clinical implications in oral cancer is not clear. The current review highlights the miRNA profile of oral cancer and discusses the diagnostic, prognostic and potential therapeutic targets with clinical implications. miRNAs mediate activation or suppression of signalling pathways associated with oral cancer. Hence, a panel of select deregulated miRNAs may indicate clinicopathological features, personalised treatment outcome and provide novel lead profiles of oral cancer. The translational applications of miRNAs may lead to better management and survival of oral cancer patients. The compiled data provides a platform for consideration of miRNA signatures as potential biomarkers for early oral cancer diagnosis, prognosis and as novel molecular therapies.

Insight toward the MicroRNA Profiling of Laryngeal Cancers: Biological Role and Clinical Impact

Head and neck squamous cell carcinoma (HNSCC), a heterogeneous disease arising from various anatomical locations including the larynx, is a leading cause of death worldwide. Despite advances in multimodality treatment, the overall survival rate of the disease is still largely dismal. Early and accurate diagnosis of HNSCC is urgently demanded in order to prevent cancer progression and to improve the quality of the patient's life. Recently, microRNAs (miRNAs), a family of small non-coding RNAs, have been widely reported as new robust tools for prediction, diagnosis, prognosis, and therapeutic approaches of human diseases. Abnormally expressed miRNAs are strongly associated with cancer development, resistance to chemo-/radiotherapy, and metastatic potential through targeting a large variety of genes. In this review, we summarize on the recent reports that emphasize the pivotal biological roles of miRNAs in regulating carcinogenesis of HNSCC, particularly laryngeal cancer. In more detail, we report the characterized miRNAs with an evident either oncogenic or tumor suppressive role in the cancers. In addition, we also focus on the correlation between miRNA deregulation and clinical relevance in cancer patients. On the basis of intriguing findings, the study of miRNAs will provide a new great opportunity to access better clinical management of the malignancies.

Role of SPRED1 in keratinocyte proliferation in psoriasis

Psoriasis is a recurrent inflammatory skin disease, affecting approximately 2% of the population. Previous studies have demonstrated that psoriatic dermal mesenchymal stem cells (DMSC) stimulated keratinocyte (KC) proliferation and that psoriasis exhibited missense SPRED1 mutations. To further investigate the molecular mechanism by which psoriatic DMSC stimulate KC proliferation, and the role of missense SPRED1 mutations in psoriasis, we assessed expression levels of miRNA, and both mRNA and protein of SPRED1 in normal human epidermal keratinocyte cells (NHEK) cocultured with either psoriatic or control DMSC. Expression levels of miRNA and mRNA were determined by RNA sequencing. Expression levels of spred1 protein were assessed using western blot analysis. Moreover, the variation in SPRED1 was also examined by whole-genome sequencing in 665 psoriatic patients, and verified by Sanger sequencing. Our results showed that coculture of NHEK with psoriatic DMSC induced 32 differentially expressed miRNA, in which expression levels of miR-1 increased approximately 16-fold over control DMSC-treated NHEK (P < 0.05). Likewise, expression levels of miR-21-3p increased over twofold (P < 0.05). Moreover, coculture of NHEK with psoriatic DMSC induced marked increase in expression levels of mRNA for MAPK3, CDC25B and CDC25C, while decreasing expression levels of SPRED1 mRNA and protein in comparison with control DMSC treatment (P < 0.05 for all between cocultured with control and psoriatic DMSC). Furthermore, psoriasis displayed non-synonymous mutation of SPRED1 enriched in exon 7: c.A881T:p.Y294F (chr15:38351210). These results suggest that dysregulation and mutations of SPRED1 may participate in the pathogenesis of psoriasis, including epidermal hyperproliferation.

Role of exosomal miR‑21 in the tumor microenvironment and osteosarcoma tumorigenesis and progression (Review)

Osteosarcoma is the most common bone tumor affecting both adolescents and children. Early detection is critical for the effective treatment of the disease. Derived from cancer cells, miR‑21 contained within exosomes in the tumor microenvironment may act on both cancer cells and the surrounding tumor microenvironment (TME), including immune cells, endothelial cells and fibroblasts. In human serum and plasm, the level of exosomal miR‑21 between osteosarcoma patients and healthy controls differs, supporting the role of miR‑21 as a biomarker for osteosarcoma. The involvement of a number of miR‑21 target genes in tumor progression suggests that miR‑21 may significantly affect the plasticity of cancer cells, leading to tumor progression, metastasis, angiogenesis and immune escape in osteosarcoma. Understanding the biogenesis and functions of exosomal miR‑21 is of great value for the diagnosis and therapy of cancer, including osteosarcoma. The present review discusses the role of miR‑21 in the tumor microenvironment, and in the development and progression of osteosarcoma, with an aim to summarize the functions of this miRNA in cancer.

Lung Cancer Cells Derived Circulating miR-21 Promotes Differentiation of Monocytes into Osteoclasts

Objective

Osteoclastogenesis is a key process in osteolytic bone metastasis (BM). Previous studies indicated that some miRNAs could regulate cancers progression and osteoclastogenesis. Our purpose was to investigate the roles of lung cancer cells-derived circulating miR-21 on osteoclastogenesis and its clinical significance in BM patients.

Materials and Methods

The difference of miRNA expression in two lung cancer cell lines SBC-5 (with characteristic BM ability) and SBC-3 (without BM ability) were analyzed by microarray and qRT-PCR. Circulating miR-21 levels of lung cancer patients with or without BM were compared by qRT-PCR. The TRAP staining was used to investigate the effects of conditioned media from lung cancer cell lines or patients’ plasma with different miR-21 levels on osteoclastogenesis. ROC curve was used to evaluate the diagnostic performance of circulating miR-21 in BM patients.

Results

We found that miR-21 expression was specifically higher in SBC-5 than that in SBC-3 cells. The supernatants of SBC-5 cells with higher-level miR-21 promoted osteoclastogenesis. Moreover, we demonstrated that the circulating miR-21 level was significantly higher in BM patients than that in non-BM patients. The plasma from BM patients with higher-level miR-21 could also promote osteoclastogenesis. Mechanistically, lung cancer cells-derived circulating miR-21 could be transferred into osteoclast precursor cells and promote osteoclastogenesis probably by inhibiting PTEN. Finally, clinical data showed that circulating miR-21 had a potential for the diagnosis of BM.

Conclusion

Overall, our findings suggested that circulating miR-21 played important roles in osteoclastogenesis of lung cancer patients and may serve as a biomarker to diagnose BM of lung cancer.

Identification of Cholangiocarcinoma Associated with Hepatolithiasis via the Combination of miRNA and Ultrasound

Background

Identification of cholangiocarcinoma (CCA) associated with hepatolithiasis (HL) is difficult. There is no effective method to discriminate CCA associated with HL (HL-CCA) from HL currently.

Objective

To explore the value of clinical data, ultrasonic characteristics and miRNA expression level in the identification of HL-CCA.

Methods

Thirty-one patients with HL-CCA in Huazhong University of Science and Technology Union Shenzhen Hospital were enrolled in the observation group, while 40 patients with HL alone were included in the control group. The clinical data, ultrasonic characteristics, and miRNA expression level of the two groups were recorded and analyzed to explore the potential indicators for the identification of HL-CCA.

Results

The accuracy of ultrasound in the diagnosis of HL-CCA was low (54.84%). Multivariate logistic regression analysis showed that liver abscess (P=0.021), indistinct border demarcation (P=0.015), non-homogenous echotexture (P=0.019), missed portal vein around lesion (P=0.032), miRNA-21 (P=0.018) and miRNA-221 (P=0.009) were the potential indicators for the identification of HL-CCA. The combined diagnosis based on logistic regression contained liver abscess, border demarcation, echotexture, portal vein around lesion, miRNA-21 and miRNA-221. The results showed that the accuracy of combined diagnosis identifying HL-CCA was the most accurate (AUC=0.911), which was significantly greater than the AUC of miRNA-21 or miRNA-221 individually (P<0.05), with a sensitivity and specificity of 77.42% and 97.50%, respectively.

Conclusion

Patients with HL-CCA show high incidence of hepatic abscess and elevated miRNA-21 and miRNA-221 expression level. The ultrasonic features are more likely to show indistinct border demarcation, non-homogenous echotexture, and missed portal vein around lesion. The combined diagnosis is more accurate in the identification of HL-CCA.

Circular RNAs: Diversity of Functions and a Regulatory Nova in Oral Medicine: A Pilot Review

Oral diseases, such as cancers, inflammation, loss of bone/tooth/soft tissues, are serious threats to human health since some can cause systemic disease and effective treatments are limited. Thus, discovering promising biomarkers for physiological and pathological processes in oral medicine, and identifying novel targets for therapy have become a most critical issue. Recently, circular RNAs (circRNAs), which were once thought to be a class of non-coding RNAs (ncRNAs), are found to be of coding potential. CircRNAs are highly present in the cytoplasm of eukaryotic cells and are key elements in the physiological and biological processes of various pathological conditions, and are also reflected in oral development and progress. Previous studies have indicated that circRNAs are involved in the initiation and development of different types of diseases and tissues (e.g., cancers, cardiovascular diseases, neural development, growth and development, wood healing, liver regeneration). Moreover, growing evidence demonstrates that circRNAs play vital roles in oral cancers and osteogenic differentiation of periodontal ligament stem cells (PDLSCs). Here, we focus on the biological characteristics of circRNAs, beginning with an overview of previous studies on the functional roles of circRNAs as diagnostic biomarkers and therapeutic targets in oral medicine. We hope this will give us a promising new comprehension of the underlying mechanisms occurring during related biological and pathological progress, and contribute to the development of effective diagnostic biomarkers and therapeutic targets for oral diseases.

mRNA Expression of CDK2AP1 in Human Breast Cancer: Correlation with Clinical and Pathological Parameters

BACKGROUND

Cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) interacts with CDK2AP2, modulates the actions of transforming growth factor-B1, cyclin-dependent kinase 2 and retinoblastoma protein, and closely interacts with micro-RNA21 and micro-RNA25. Our objective was to determine if CDK2AP1 mRNA expression levels were consistent with tumour-suppressive functions in breast cancer.

MATERIALS AND METHODS

A total of 134 samples were analysed. CDK2AP1 mRNA levels were measured using quantitative polymerase chain reaction (RT-PCR) and normalised against glyceraldehyde 3-phosphate dehydrogenase mRNA. Levels in breast cancer and adjacent non-cancerous breast tissue were analysed against pathological and clinical parameters (TNM staging, survival over a 10-year follow-up period).

RESULTS

Normalised CDK2AP1 expression was 38-fold higher in adjacent non-cancerous breast tissue than in breast cancer. CDK2AP1 expression in disease-free patients at 10 years was more than threefold that of patients who died of breast cancer. However, neither of these differences in expression levels reached statistical significance. CDK2AP1 mRNA levels were higher in TNM1 compared to TNM3 (p=0.016) and with TNM4 (p=0.016). There were no significant associations between CDK2AP1 expression and estrogen receptor status, tumour grade and tumour type. There was no significant difference in overall survival between patients with high and those with low CDK2AP1 mRNA levels after a median follow-up of 10 years (Kaplan-Meier analysis, p=0.872).

CONCLUSION

To our knowledge, this is the first study in the literature to examine the mRNA expression of CDK2AP1 in human breast cancer over a long-term follow-up period. A compelling relationship exists between high CDK2AP1 mRNA expression and lower TNM classification of breast cancer, which is consistent with CDK2AP1 having a tumour-suppressive function.

The role of microRNAs in embryonic stem cell and induced pluripotent stem cell differentiation in male germ cells

New perspectives have been opened by advances in stem cell research for reproductive and regenerative medicine. Several different cell types can be differentiated from stem cells (SCs) under suitable in vitro and in vivo conditions. The differentiation of SCs into male germ cells has been reported by many groups. Due to their unlimited pluripotency and self-renewal, embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can be used as valuable tools for drug delivery, disease modeling, developmental studies, and cell-based therapies in regenerative medicine. The unique features of SCs are controlled by a dynamic interplay between extrinsic signaling pathways, and regulations at epigenetic, transcriptional and posttranscriptional levels. In recent years, significant progress has been made toward better understanding of the functions and expression of specific microRNAs (miRNAs) in the maintenance of SC pluripotency. miRNAs are short noncoding molecules, which play a functional role in the regulation of gene expression. In addition, the important regulatory role of miRNAs in differentiation and dedifferentiation has been recently demonstrated. A balance between differentiation and pluripotency is maintained by miRNAs in the embryo and stem cells. This review summarizes the recent findings about the role of miRNAs in the regulation of self-renewal and pluripotency of iPSCs and ESCs, as well as their impact on cellular reprogramming and stem cell differentiation into male germ cells.

Simultaneous downregulation of miR-21 and miR-155 through oleuropein for breast cancer prevention and therapy

Breast cancer (BC) is the leading cause of cancer mortality in women worldwide. It recently was proven that miRNAs play a critical role in BC development. The use of natural agents for control of cancer by modulating miRNAs is promising. Oleuropein is a natural polyphenolic agent with anti-neoplastic properties and is well tolerated by humans. This study was undertaken to determine the therapeutic effects of oleuropein through modulation of master oncomiRs (miR-21 and miR-155) in BC cells. The present study provides the first link between miRNA and oleuropein as a mechanism in BC. MCF-7 cells were tested with and without oleuropein and the cell viability, apoptosis, and migration were examined. The effect of oleuropein on miR-21 and miR-155 expression was assessed through qRT-PCR. It was found that oleuropein induced apoptosis and retarded cell migration and invasion in a dose-dependent manner in the human MCF7 BC cell line. It was observed that oleuropein significantly decreased expression of both miR-21 and miR-155 over time in a dose-dependent manner. These results demonstrate that oleuropein is a potential therapeutic and preventive agent for BC. Oleuropein exhibits an anti-cancer effect by modulation of tumor suppressor gene expression, which is targeted by oncomiRs.

miRNA-21 ablation protects against liver injury and necroptosis in cholestasis

Inhibition of microRNA-21 (miR-21) prevents necroptosis in the mouse pancreas. Necroptosis contributes to hepatic necro-inflammation in the common bile duct ligation (BDL) murine model. We aimed to evaluate the role of miR-21 in mediating deleterious processes associated with cholestasis. Mechanistic studies established a functional link between miR-21 and necroptosis through cyclin-dependent kinase 2-associated protein 1 (CDK2AP1). miR-21 expression increased in the liver of primary biliary cholangitis (PBC) patients and BDL wild-type (WT) mice at both 3 and 14 days. Notably, under BDL, miR-21 ^-/- mice displayed decreased liver injury markers in serum compared with WT mice, accompanied by reduced hepatocellular degeneration, oxidative stress and fibrosis. Hallmarks of necroptosis were decreased in the liver of BDL miR-21 ^-/- mice, via relieved repression of CDK2AP1. Further, miR-21 ^-/- mice displayed improved adaptive response of bile acid homeostasis. In conclusion, miR-21 ablation ameliorates liver damage and necroptosis in BDL mice. Inhibition of miR-21 should arise as a promising approach to treat cholestasis.

A Looking-Glass of Non-coding RNAs in oral cancer

Oral cancer is a multifactorial pathology and is characterized by the lack of efficient treatment and accurate diagnostic tools. This is mainly due the late diagnosis; therefore, reliable biomarkers for the timely detection of the disease and patient stratification are required. Non-coding RNAs (ncRNAs) are key elements in the physiological and pathological processes of various cancers, which is also reflected in oral cancer development and progression. A better understanding of their role could give a more thorough perspective on the future treatment options for this cancer type. This review offers a glimpse into the ncRNA involvement in oral cancer, which can help the medical community tap into the world of ncRNAs and lay the ground for more powerful diagnostic, prognostic and treatment tools for oral cancer that will ultimately help build a brighter future for these patients.

miR‐31 Regulates Spermatogonial Stem Cells Meiosis via Targeting Stra8

Stra8 (stimulated by retinoic acid gene 8) is a specific gene that is expressed in mammalian germ cells during transition from mitosis to meiosis and plays a key role in the initiation of meiosis in mammals and birds. So, the evaluation of the Stra8 pathway in cSSCs may provide a deeper insight into mammalian spermatogenesis. miRNA was also an important regulating factor for meiosis of SSCs. However, there is currently no data indicating that miRNA regulate the meiosis of SSCs via Stra8. Here, we predicted the prospective miRNA targeting to Stra8 using the online Bioinformatics database‐Targetscan, and performed an analysis of the dual‐luciferase recombinant vector, pGL3‐CMV‐LUC‐MCS‐Stra8‐3′UTR. miR‐31 mimics (miR‐31m), miR‐31 inhibitors (miR‐31i), Control (NC, scrambled oligonucleotides transfection) were transfected into cSSCs; Stra8 and miRNA were analyzed by RT‐qPCR, immunofluorescence, and Western blot. The detection of haploid was conducted by flow cytometry. The results showed that miR‐31 regulates meiosis of cSSCs via targeting Stra8 in vitro and in vivo. Our study identifies a new regulatory pathway that miR‐31 targets Stra8 and inhibits spermatogenesis. J. Cell. Biochem. 118: 4844–4853, 2017. © 2017 Wiley Periodicals, Inc.

Exosomes Transfer Among Different Species Cells and Mediating miRNAs Delivery

Exosomes, the natural vehicles of intercellular communication, transfer proteins, mRNAs, and microRNAs (miRNAs) and mediate many physiological and pathological processes. It is not clear that whether exosomal miRNAs could regulate gene expression across species, though some studies suggest interactions of exosomal miRNAs between cells. In this report, we have isolated exosomes from rat PC12 cells and assessed their internalization by human cancer Hela cells. The internalized exosomes were located in Hela lysosomes. Human PTEN expression was significantly deregulated due to miR-21 delivered by rat cell exosomes. Our results prove that exosomes could incorporate between cells of different species and could regulate the protein expressions in the recipient cells by delivering the enclosed miRNAs. Thus our study foreshadows a futuristic treatment approach of utilizing miRNA enclosed exosome vehicles sans species concerns in combating various diseases/ regulating abnormal proteins. J. Cell. Biochem. 118: 4267-4274, 2017. © 2017 Wiley Periodicals, Inc.

Current Status and Perspectives Regarding LNA-Anti-miR Oligonucleotides and microRNA miR-21 Inhibitors as a Potential Therapeutic Option in Treatment of Colorectal Cancer

Colorectal cancer (CRC) is among the leading causes of cancer-related death, principally due to its metastatic spread and multifactorial chemoresistance. The therapeutic failure can also be explained by inter- or intra-tumor genetic heterogeneity and tumor stromal content. Thus, the identification of novel prognostic biomarkers and therapeutic options are warranted in the management of CRC patients. There are data showing that microRNA-21 is elevated in different types of cancer, particularly colon adenocarcinoma and that this is association with a poor prognosis. This suggests that microRNA-21 may be of value as a potential therapeutic target. Furthermore, locked nucleic acid (LNA)-modified oligonucleotides have recently emerged as a therapeutic option for targeting dysregulated miRNAs in cancer therapy, through antisense-based gene silencing. Further work is required to identify innovative anticancer drugs that improve the current therapy either through novel combinatorial approaches or with better efficacy than conventional drugs. We aimed to provide an overview of the preclinical and clinical studies targeting key dysregulated signaling pathways in CRC as well as the therapeutic application of LNA-modified oligonucleotides, and miR inhibitors in the treatment of CRC patients. J. Cell. Biochem. 118: 4129-4140, 2017. © 2017 Wiley Periodicals, Inc.

Prognostic value of cross-omics screening for kidney clear cell renal cancer survival

Background

Kidney renal clear cell carcinoma (KIRC) is a type of cancer that is resistant to chemotherapy and radiotherapy and has limited treatment possibilities. Large-scale molecular profiling of KIRC tumors offers a great potential to uncover the genetic and epigenetic changes underlying this disease and to improve the clinical management of KIRC patients. However, in practice the clinicians and researchers typically focus on single-platform molecular data or on a small set of genes. Using molecular and clinical data of over 500 patients, we have systematically studied which type of molecular data is the most informative in predicting the clinical outcome of KIRC patients, as a standalone platform and integrated with clinical data.

Results

We applied different computational approaches to preselect on survival-predictive genomic markers and evaluated the usability of mRNA/miRNA/protein expression data, copy number variation (CNV) data and DNA methylation data in predicting survival of KIRC patients. Our analyses show that expression and methylation data have statistically significant predictive powers compared to a random guess, but do not perform better than predictions on clinical data alone. However, the integration of molecular data with clinical variables resulted in improved predictions. We present a set of survival associated genomic loci that could potentially be employed as clinically useful biomarkers.

Conclusions

Our study evaluates the survival prediction of different large-scale molecular data of KIRC patients and describes the prognostic relevance of such data over clinical-variable-only models. It also demonstrates the survival prognostic importance of methylation alterations in KIRC tumors and points to the potential of epigenetic modulators in KIRC treatment.

Reviewers

An extended abstract of this research paper was selected for the CAMDA Satellite Meeting to ISMB 2015 by the CAMDA Programme Committee. The full research paper then underwent one round of Open Peer Review under a responsible CAMDA Programme Committee member, Djork-Arné Clevert, PhD (Bayer AG, Germany). Open Peer Review was provided by Martin Otava, PhD (Janssen Pharmaceutica, Belgium) and Hendrik Luuk, PhD (The Centre for Disease Models and Biomedical Imaging, University of Tartu, Estonia). The Reviewer comments section shows the full reviews and author responses.

Electronic supplementary material

The online version of this article (doi:10.1186/s13062-016-0170-1) contains supplementary material, which is available to authorized users.

Locked nucleic acid anti-miR-21 inhibits cell growth and invasive behaviors of a colorectal adenocarcinoma cell line: LNA-anti-miR as a novel approach

Colorectal cancer (CRC) is the third leading cause of cancer-related death and has an extremely poor prognosis. Dysregulation of microRNAs (miRNAs) has been shown to be involved in the pathogenesis and progression of many malignancies. Recent data suggest that microRNA-21 (miR-21) is significantly elevated in different types of cancer, especially colon adenocarcinoma. Against this background, locked nucleic acid (LNA)-modified oligonucleotides have recently been suggested as a novel approach for targeting miRNAs as antisense-based gene silencing. The aim of the current study was to explore the functional role of LNA-anti-miR-21 in a colon adenocarcinoma LS174T cell line. LS174T cells were transfected with LNA-anti-miR-21 for 24, 48 and 72 h. Quantitative real-time reverse transcriptase-PCR (qRT-PCR) was performed to assess miR-21 expression by LNA-anti-miR-21. The viability of the cells was evaluated by MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) assay and Annexin V/propidium iodide staining assay was used to detect apoptosis. Moreover, invasive behavior of the cells was evaluated before and after therapy by transwell assay. LNA-anti-miR-21 was successfully transfected in human LS174T cells and suppressed the endogenous miR-21. LNA-anti-miR-21 inhibited the cells' growth followed by induction of apoptosis. LNA-anti-miR-21 (50 pmol/μl) reduced the invasive behaviors of LS174T cells after 24 h, compared with untreated cells and scrambled LNA-transfected cells. However, this effect was more pronounced after 72 h. Our findings suggest the therapeutic potential of LNA-anti-miR-21 in a colon adenocarcinoma for targeting miR-21 expression. Further studies are warranted to investigate the molecular mechanisms underlying this novel inhibitor in colorectal cancer to establish its potential value for treatment of CRC patients with high miR-21 expression.

p12CDK2-AP1 interacts with CD82 to regulate the proliferation and survival of human oral squamous cell carcinoma cells

p12 cyclin-dependent kinase 2 (CDK2)-associating protein 1 (p12CDK2-AP1) has been demonstrated to negatively regulate the activity of CDK2. However, the underlying molecular mechanism remains largely unknown. We aimed to determine the potential binding proteins of p12CDK2-AP1 and to elucidate the role of p12CDK2-AP1 in the regulation of the proliferation, invasion, apoptosis, and in vivo growth of human oral squamous cell carcinoma cells. The protein-protein interaction was predicted using computational decision templates. The predicted p12CDK2‑AP1 interacting proteins were overexpressed in human oral squamous cell carcinoma OSCC-15 cells, and the protein binding was examined using co-precipitation (Co-IP). Cell proliferation and invasion were determined via MTT assay and Transwell system, respectively. Cell apoptosis was evaluated using Annexin V-FITC/PI double staining followed by flow cytometric analysis. The in vivo growth of OSCC-15 cells was examined in nude mouse tumor xenografts. We found that overexpression of either p12CDK2-AP1 or CD82 significantly suppressed the proliferation and invasion but promoted the apoptosis of OSCC-15 cells (P<0.05). Importantly, combined overexpression of p12CDK2-AP1 and CD82 showed synergistic antitumor activity compared with the overexpression of a single protein alone (P<0.05). Additionally, the simultaneous overexpression of p12CDK2-AP1 and CD82 significantly suppressed the in vivo tumor growth of OSCC-15 cells in nude mice compared with the negative control (P<0.05). Our findings indicate that p12CDK2-AP1 interacts with CD82 to play a functional role in suppressing the in vitro and in vivo growth of OSCC-15 cells.

Triptolide reduces proliferation and enhances apoptosis of human non-small cell lung cancer cells through PTEN by targeting miR-21

Triptolide is used in traditional Chinese medicine. It has the advantages of a unique mechanism of action, a wide antitumor spectrum, multiple targets, multi-channel effects and low toxicity. The current study was conducted to evaluate whether the potential anticancer effects of triptolide reduces proliferation and enhances apoptosis of human non‑small cell lung cancer (NSCLC) cells, and to assess the underlying anticancer mechanisms. In PC‑9 cells, treatment with triptolide reduced cell proliferation and increased cell apoptosis and caspase‑3 and 9 activity. Triptolide treatment reduced miR‑21 expression and enhanced phosphatase and tensin homolog (PTEN) protein expression levels in the PC‑9 cells. Furthermore, the upregulation of miR‑21 expression levels suppressed the effect of triptolide on cell viability and PTEN protein expression levels in PC‑9 cells. To the best of our knowledge, the present study is the first to demonstrate that triptolide reduced the proliferation and enhanced the apoptosis of human NSCLC cells through PTEN by targeting miR-21.

Down-regulation of miR-320 associated with cancer progression and cell apoptosis via targeting Mcl-1 in cervical cancer

Our previous studies have demonstrated overexpression of Mcl-1 in cervical cancer tumorigenesis. However, the molecular mechanism of its overexpression remains not elucidated. MiR-320 has been reported to be down-regulated in various types of cancer, and bioinformatics prediction indicated that it may regulate the expression of Mcl-1. The aim of this study is to investigate the role of miR-320 and its target gene Mcl-1 in cervical cancer progression and to assess their clinical significance. miR-320 and Mcl-1 expressions in human cervical cancer tissues were investigated by qRT-PCR, in situ hybridization, and immunohistochemical staining, respectively. The clinicopathological implications of these molecules were analyzed. Bioinformatic prediction and luciferase assays were employed to identify the predicted microRNA (miRNA) which regulates Mcl-1. The apoptosis, proliferation, migration, and invasion assays were performed to investigate the effect of miR-320 on the cervical cancer cells. MiR-320 expression is significantly down-regulated versus Mcl-1 expression is up-regulated in cervical cancer tissues compared with normal controls with a negative correlation between them. Luciferase assay showed that miR-320 negatively regulates Mcl-1 expression. In addition, miR-320 induces apoptosis via down-regulation of Mcl-1 and activation of caspase-3 but inhibits cell proliferation, migration, invasion, and tumorigenesis in cervical cancer cells. Our studies show that miR-320 expression is decreased in cervical cancer, and its expression is negatively correlated with Mcl-1 expression in cervical cancer. In addition, miR-320 inhibits cervical cancer progression by down-regulation of Mcl-1. These results indicate that miR-320 may be an important biomarker and target for diagnosis and treatment of cervical cancer patient.

Global miRNA Expression Profiling Identifies miR-1290 as Novel Potential oncomiR in Laryngeal Carcinoma

Background

Laryngeal squamous cell carcinoma (LSCC) is the most common group among head and neck cancers. LSCC is characterized by a high incidence in Europe. With the aim of better understanding its genetic background we performed global miRNA expression profiling of LSCC cell lines and primary specimens. By this approach we identified a cohort of 33 upregulated and 9 downregulated miRNA genes in LSCC as compared to epithelial no tumor controls.

Results

Within this group we identified overexpression of the novel miR-1290 gene not reported in the context of LSCC before. Using a combined bioinformatical approach in connection with functional analysis we delineated two putative target genes of miR-1290 namely ITPR2 and MAF which are significantly downregulated in LSCC. They are interesting candidates for tumor suppressor genes as they are implicated in apoptosis and other processes deregulated in cancer.

Conclusion

Taken together, we propose miR-1290 as the new oncomiR involved in LSCC pathogenesis. Additionally, we suggest that the oncogenic potential of miR-1290 might be expressed by the involvement in downregulation of its target genes MAF and ITPR2.

miR-205 promotes proliferation and invasion of laryngeal squamous cell carcinoma by suppressing CDK2AP1 expression

Background

The aberrant expression of microRNAs (miRNAs) has been found in various types of cancer. miR-205 was reported to be upregulated in laryngeal squamous cell carcinoma (LSCC) tissues, however, the mechanisms by which miR-205 functions as a regulator of LSCC are largely unknown.

Results

In this study, Real-time qPCR and Western blot assay showed that expression of miR-205 was upregulated and expression of cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) was downregulated in LSCC tissues. The expression levels of miR-205 were negatively related to those of CDK2AP1 in LSCC tissues and cell lines. Moreover, we found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the CDK2AP1 expression in LSCC cells. 3-(4,5-dimethylthiazal-2-yl)-2,5-diphenyl-tetrazolium bromide assays and transwell invasion assay were performed to test the proliferation and invasion of LSCC cells. Gelatin zymography was used to detect the activity of MMP2 and MMP9. CDK2AP1, c-Myc and CyclinD1 expression in cells was assessed with Western blotting. We found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the expression of CDK2AP1 in LSCC cells. In addition, miR-205 significantly induced cell proliferation and invasion by suppressing CDK2AP1 expression. Consistent with miR-205 inhibitors, overexpressed CDK2AP1 suppressed the activity of MMP2 and MMP9 and c-Myc and CyclinD1 expression in LSCC cells.

Conclusion

These findings help us to better elucidate the molecular mechanisms of LSCC progression and provide a new theoretical basis to further investigate miR-205 as a potential biomarker and a promising approach for LSCC treatment.

Circulating microRNAs as prognostic therapy biomarkers in head and neck cancer patients

BACKGROUND

The prediction of therapy response in head and neck squamous cell cancer (HNSCC) requires biomarkers, which are also a prerequisite for personalised therapy concepts. The current study aimed to identify therapy-responsive microRNAs (miRNAs) in the circulation that can serve as minimally invasive prognostic markers for HNSCC patients undergoing radiotherapy.

METHODS

We screened plasma miRNAs in a discovery cohort of HNSCC patients before therapy and after treatment. We further compared the plasma miRNAs of the patients to age- and sex-matched healthy controls. All miRNAs identified as biomarker candidates were then confirmed in an independent validation cohort of HNSCC patients and tested for correlation with the clinical outcome.

RESULTS

We identified a signature of eight plasma miRNAs that differentiated significantly (P=0.003) between HNSCC patients and healthy donors. MiR-186-5p demonstrated the highest sensitivity and specificity to classify HNSCC patients and healthy individuals. All therapy-responsive and patient-specific miRNAs in plasma were also detectable in tumour tissues derived from the same patients. High expression of miR-142-3p, miR-186-5p, miR-195-5p, miR-374b-5p and miR-574-3p in the plasma correlated with worse prognosis.

CONCLUSIONS

Circulating miR-142-3p, miR-186-5p, miR-195-5p, miR-374b-5p and miR-574-3p represent the most promising markers for prognosis and therapy monitoring in the plasma of HNSCC patients. We found strong evidence that the circulating therapy-responsive miRNAs are tumour related and were able to validate them in an independent cohort of HNSCC patients.

Platelet miRNAs and cardiovascular diseases

Activated platelets play a critical role in the acute complications of atherosclerosis that cause life-threatening ischemic events at late stages of the disease. The miRNAs are a novel class of small, non-coding RNAs that play a significant role in both inflammatory and cardiovascular diseases. The miRNAs are known to be present in platelets and exert important regulatory functions. Here we systematically examine the genes that are regulated by platelet miRNAs (miRNA-223,miRNA-126,miRNA-21, miRNA-24 and miRNA-197) and the association with cardiovascular disease risks. Platelet-secreted miRNAs could be novel biomarkers associated with cardiovascular diseases.

Circulating MicroRNA-21 Is a Potential Diagnostic Biomarker in Gastric Cancer

MicroRNA-21 was upexpressed in gastric cancer (GC) indicating that it is a potential diagnostic biomarker for GC. In this study, 50 GC patients and 50 healthy controls were recruited. miR-21 levels in serum and peripheral blood mononuclear cells (PBMCs) were quantified using quantitative real-time PCR. CA199, and CEA were measured using electrochemiluminescence assay. The sensitivity and specificity of circulating miR-21, CA199 and CEA in GC diagnosis, the correlation of circulating miR-21 to clinicopathological features, and the diagnostic value of miR-21 in different GC stages were determined. The levels of miR-21 in both serum and PBMCs increased significantly in GC patients comparing to healthy controls; however, no correlation was observed between circulating miR-21 level and clinicopathological features. The sensitivity and specificity of miR-21 in serum and PBMCs, and CA199 and CEA in GC diagnosis were 88.4%, 79.6%, 81.3%, 73.4%, 60.5%, 55.9%, and 68.6%, 59.3%, respectively. The positive prediction rates of circulating miR-21 in GC stages I to IV were all around 90%, while those of CA199 and CEA were around or less than 50%. Our data suggest circulating miR-21 (both in serum and in PBMCs) can serve as a good biomarker for GC and could be used in diagnosis of early (stage I) and late GC (stage IV).

Role of microRNAs in mammalian spermatogenesis and testicular germ cell tumors

microRNAs (miRNAs) are a class of small endogenous RNAs, 19–25 nucleotides in size, which play a role in the regulation of gene expression at transcriptional and post-transcriptional levels. Spermatogenesis is a complex process through which spermatogonial stem cells (SSCs) proliferate and differentiate into mature spermatozoa. A large number of miRNAs are abundantly expressed in spermatogenic cells. Growing evidence supports the essential role of miRNA regulation in normal spermatogenesis and male fertility and cumulative research has shown that this form of regulation contributes to the etiology of testicular germ cell tumors (TGCTs). In this review, we addressed recent advancements of miRNA expression profiles in testis and focused on the regulatory functions of miRNA in the process of SSC renewal, spermatogonial mitosis, spermatocyte meiosis, spermiogenesis, and the occurrence of TGCTs.

Regulation of cancer metastasis by cell-free miRNAs

MicroRNAs (miRNAs) are integral molecules in the regulation of numerous physiological cellular processes that have emerged as critical players in cancer initiation and metastatic progression, both by promoting and suppressing metastasis. Recently, cell-free miRNAs shed from cancer cells into circulation have been reported in cancer patients, raising hope for development of novel biomarkers that can be routinely measured in easily accessible samples. In fact, establishing miRNA expression in the circulation likely has advantages over determination in primary tumor tissue, further augmenting the potential applications of miRNA detection in oncological practice. In addition, secretion of miRNAs impacting distant cell signaling or promoting the formation of a niche that sustains a distant tumor microenvironment allows for new treatment approaches to thwart cancer progression.

Krüppel-like factor 9 inhibits glioma cell proliferation and tumorigenicity via downregulation of miR-21

Krüppel-like factors (KLFs) are zinc finger-containing transcription factors that play key roles in the regulation of differentiation and development as well as biological processes central to the development of malignancies. Increasing evidence indicates that Krüppel-like factor 9 (KLF9) plays a critical role in regulating tumorigenesis. However, the biological role and molecular mechanism of KLF9 in glioma progression remain unclear. Herein, we found that KLF9 expression was strongly reduced in gliomas. Reduced KLF9 expression promoted glioma cell proliferation. Importantly, re-constitution of KLF9 expression inhibited glioma cell proliferation and tumor growth in vivo. Furthermore, we determined that KLF9 interacted with the miR-21 promoter, leading to suppression of miR-21 expression and cell cycle arrest. Taken together, our findings indicate a novel mechanism for KLF function in tumorigenesis and may also suggest new targets for clinical intervention in human cancer.

MicroRNA-21 regulates T-cell apoptosis by directly targeting the tumor suppressor gene Tipe2

MicroRNAs (MiRs) are short noncoding RNAs that can regulate gene expression. It has been reported that miR-21 suppresses apoptosis in activated T cells, but the molecular mechanism remains undefined. Tumor suppressor Tipe2 (or tumor necrosis factor-α-induced protein 8 (TNFAIP8)-like 2 (TNFAIP8L2)) is a newly identified anti-inflammatory protein of the TNFAIP8 family that is essential for maintaining immune homeostasis. We report here that miR-21 is a direct target of nuclear factor-κB and could regulate Tipe2 expression in a Tipe2 coding region-dependent manner. In activated T cells and macrophages, Tipe2 expression was markedly downregulated, whereas miR-21 expression was upregulated. Importantly, Tipe2-deficient T cells were significantly less sensitive to apoptosis. Conversely, overexpression of Tipe2 in EL-4 T cells increased their susceptibility to activation-induced apoptosis. Therefore, Tipe2 provides a molecular bridge between miR-21 and cell apoptosis; miR-21 suppresses apoptosis in activated T cells at least in part through directly targeting tumor suppressor gene Tipe2.

Interaction between p12CDK2AP1 and a novel unnamed protein product inhibits cell proliferation by regulating the cell cycle

Human p12CDK2AP1 protein is encoded by the cyclin‑dependent kinase 2‑associated protein 1 (CDK2AP1) gene. This protein suppresses cell growth, differentiation and angiogenesis in numerous types of carcinoma by interacting with certain cell cycle proteins, including CDK2 and DNA polymerase α/primase. p12CDK2AP1 exerts its functions predominantly through protein‑protein interactions. Therefore, the identification of other p12CDK2AP1‑interacting proteins may clarify its role in cell cycle regulation and carcinogenesis. The aim of this study was to identify additional p12CDK2AP1‑interacting proteins. A novel unnamed protein product (UPP, BC006130) was identified through using a yeast two‑hybrid system. The interaction of p12CDK2AP1 with the UPP was further verified by glutathione S-transferase pull‑down and co‑immunoprecipitation experiments in vitro. The qPCR results following overexpression and siRNA assays demonstrated that the expression levels of the UPP were mediated by the CDK2AP1 gene. Furthermore, overexpression of the UPP gene was shown to shorten the length of the G2/M phase of the cell cycle in normal and tumor cell lines in a flow cytometry assay. The results of human tumor xenografts experiments in Balb/c nude mice indicated that stable transfection with the UPP gene was able to inhibit tumor cell proliferation in vivo. Overall, this study identified and characterized a novel interactive protein of p12CDK2AP1, which may inhibit cell proliferation by mediating the cell cycle. It expands the understanding of the mechanisms of p12CDK2AP1 and its potential as a cancer therapeutic target.

MicroRNA-21 promotes oral cancer invasion via the Wnt/β-catenin pathway by targeting DKK2

MicroRNA-21 (miR-21) is overexpressed in a wide variety of cancers and has been related to cellular proliferation, apoptosis, and invasion; however, the function of miR-21 is unknown in oral tongue squamous cell carcinoma (OTSCC). The purpose of this study was to examine miR-21 expression in OTSCC, correlate it with clinicopathological factors, and investigate its contribution to OTSCC cell invasion. MiR-21 expression in 79 primary OTSCCs was evaluated using locked nucleic acid in situ hybridization, and correlation was examined with the clinicopathological factors. To determine the miR-21 target, we searched for molecular genes involved in tumor invasion using the commonly cited prediction program miRanda. In an OTSCC cell line, SCC25 cells, we further evaluated whether miR-21 contributes to cell invasiveness by blocking its expression with a specific knockdown LNA probe and confirmed the direct target by Matrigel invasion assay and Western blotting. MiR-21 overexpression was detected in 60 of 79 cases (75.9 %) and correlated with the pattern of invasion (P = 0.016). We selected DKK2 as a Wnt/antagonist involved in tumor invasion. MiR-21 overexpression was significantly correlated with the DKK2-/β-catenin- immunohistochemical phenotype. Knockdown of miR-21 significantly decreased the invasion potential of SCC25 cells with up-regulated DKK2. It was found that miR-21 is overexpressed and associated with tumor invasion in OTSCC, and that miR-21 promotes OTSCC cell invasion via the Wnt/β-catenin pathway by targeting DKK2 in vitro. These results suggest that miR-21 may be a potential therapeutic target for OTSCC treatment.

Microarray and deep sequencing cross-platform analysis of the mirRNome and isomiR variation in response to epidermal growth factor

Background

Epidermal Growth Factor (EGF) plays an important function in the regulation of cell growth, proliferation, and differentiation by binding to its receptor (EGFR) and providing cancer cells with increased survival responsiveness. Signal transduction carried out by EGF has been extensively studied at both transcriptional and post-transcriptional levels. Little is known about the involvement of microRNAs (miRNAs) in the EGF signaling pathway. miRNAs have emerged as major players in the complex networks of gene regulation, and cancer miRNA expression studies have evidenced a direct involvement of miRNAs in cancer progression.

Results

In this study, we have used an integrative high content analysis approach to identify the specific miRNAs implicated in EGF signaling in HeLa cells as potential mediators of cancer mediated functions. We have used microarray and deep-sequencing technologies in order to obtain a global view of the EGF miRNA transcriptome with a robust experimental cross-validation. By applying a procedure based on Rankprod tests, we have delimited a solid set of EGF-regulated miRNAs. After validating regulated miRNAs by reverse transcription quantitative PCR, we have derived protein networks and biological functions from the predicted targets of the regulated miRNAs to gain insight into the potential role of miRNAs in EGF-treated cells. In addition, we have analyzed sequence heterogeneity due to editing relative to the reference sequence (isomiRs) among regulated miRNAs.

Conclusions

We propose that the use of global genomic miRNA cross-validation derived from high throughput technologies can be used to generate more reliable datasets inferring more robust networks of co-regulated predicted miRNA target genes.

MicroRNA Deregulations in Head and Neck Squamous Cell Carcinomas

Objectives

Head and neck/oral cancer, predominantly head and neck squamous cell carcinoma (HNSCC), is the sixth most common cancer in the world. While substantial advances have been made to define the genomic alterations associated with head and neck/oral cancer, most studies are focused on protein coding genes. The aim of this article is to review the current literature on identified genomic aberrations of non-coding genes (e.g., microRNA) in head and neck/oral cancer (HNOC), and their contribution to the initiation and progression of HNOC.

Material and Methods

A comprehensive review of the available literature relevant to microRNA deregulation in HNSCC/HNOC, was undertaken using PubMed, Medline, Scholar Google and Scopus. Keywords for the search were: microRNA and oral cancer, microRNA and squamous cell carcinoma, microRNA deregulation and oral cancer, microRNA and carcinogenesis in the head and neck/oral cavity. Only full length articles in the English language were included.

Results

We recently identified a panel of microRNA deregulations that were consistently observed in HNSCC [Chen et al., Oral Oncol. 2012;48(8):686-91], including 7 consistently up-regulated microRNAs (miR-21, miR-7, miR-155, miR-130b, miR-223, miR-34b), and 4 consistently down-regulated microRNAs (miR-100, miR-99a, miR-125b, miR-375). In this review, we will first provide an overview on microRNA and HNSCC. We will then provide a comprehensive review on the roles of microRNA deregulations in HNSCC. The functional significance of the identified HNSCC-associated microRNAs and a number of other relevant microRNAs (e.g., miR-138, miR-98, miR-137, miR-193a and miR-218) will be discussed in detail.

Conclusions

Based on current literature, microRNA deregulation plays a major role in head and neck/oral cancer.

Cyclin-dependent kinase 2-associated protein 1 suppresses growth and tumorigenesis of lung cancer

Cyclin-dependent kinase 2-associated protein 1 (CDK2AP1), a growth suppressor that negatively regulates CDK2 activity, has been implicated in various types of cancer; yet its role in lung cancer remains unclear. In the present study, a lentivirus-based system was used to specifically downregulate or upregulate CDK2AP1 expression. A549 lung cancer cells were treated with RNAi (RNA interference) or lentiviral vectors for overexpression. Ectopic overexpression of CDK2AP1 in A549 cells in vitro greatly impaired their proliferation and colony-forming ability and enhanced their chemosensitivity to cisplatin and paclitaxel and caused cell cycle arrest at G1/S transition accompanied by the reduction of expression of CDK4 and CDK7. Injection of the ectopically CDK2AP1-overexpressing A549 cells into nude mice resulted in growth arrest of solid lung cancer tumors in vivo. Knockdown of CDK2AP1 in A549 cells, however, gave rise to the opposite effects including promoting cell proliferation/growth, cell cycling in vitro and enhancing tumorigenesis in vivo. These results suggest that CDK2AP1 plays an important role in modulating the growth and tumorigenesis of lung cancer cells and also has significant effects on the chemosensitivity of pulmonary malignancies to chemotherapeutics. Hence, this study extends our knowledge on the relationship between CDK2AP1 and oncogenesis of lung cancer, indicating that CDK2AP1 may serve as a new molecular target for future lung cancer therapy.

The novel miR-7515 decreases the proliferation and migration of human lung cancer cells by targeting c-Met

MicroRNAs (miRNA) are small noncoding RNAs that regulate gene expression in human diseases, including lung cancer. miRNAs have oncogenic and nononcogenic functions in lung cancer. In this study, we report the identification of a novel miRNA, miR-7515, from lung cancer cells. The novel miR-7515 was characterized using various predictive programs and experimental methods. miR-7515 was able to forming a stem-loop structure and its sequence was conserved in mammals. The expression level of miR-7515 in lung cancer cells and tissues was profiled using TaqMan miRNA assays. miR-7515 was downregulated in lung cancer compared with normal human lung cells and tissues. The target of miR-7515 was determined using a dual luciferase reporter assay. Expression of the target gene was determined by quantitative RT-PCR and Western blot analysis after transfection with miR-7515. miR-7515 directly suppressed human mesenchymal-epithelial transition factor (c-Met) by binding to the 3' untranslated region (UTR). Overexpression of miR-7515 significantly decreased cell-cycle-related proteins downstream of c-Met through c-Met inhibition. Cell proliferation and migration were examined using the XTT proliferation assay and the Transwell migration assay. miR-7515 led to decreased cell proliferation, migration and invasion in a lung cancer cell line. These results suggest that miR-7515 plays an important role in the proliferation and migration of lung cancer cells through c-Met regulation.

Lycopene inhibits hepatic steatosis via microRNA-21-induced downregulation of fatty acid-binding protein 7 in mice fed a high-fat diet

SCOPE

Nonalcoholic fatty liver disease (NAFLD) is a chronic disorder characterized by hepatic fat accumulation and abnormal lipid metabolism. Here, we investigated the protective effect of lycopene on high-fat diet-induced hepatic steatosis and fatty acid-induced intracellular lipid accumulation by miRNA regulation.

METHODS AND RESULTS

C57BL/6J mice were fed high-fat diet with or without 0.05% lycopene for 8 weeks. Hepa 1-6 cells were treated with stearic acid (SA) after 24 h pretreatment with lycopene. Treatment of lycopene improved hepatic steatosis in high-fat-fed mice and reduced intracellular lipid accumulation induced by SA in Hepa 1-6 cells. We demonstrated that miR-21 expression was decreased in livers from high-fat diet-fed mice and Hepa 1-6 cells treated with SA. Lycopene normalized the downregulation of miR-21, which led to the downregulation of fatty acid-binding protein 7 (FABP7), a direct target of miR-21, at both the transcriptional and translational levels. This specific negative regulation of miR-21 was achieved by targeting the FABP7 3'UTR. Upregulation of miR-21 markedly blocked SA-induced intracellular lipid accumulation by blocking FABP7 expression. Moreover, silencing of FABP7 reduced SA-evoked lipid accumulation in Hepa 1-6 cells.

CONCLUSION

The results suggest that lycopene may be a useful functional compound for treating NAFLD by regulating hepatic lipid metabolism.

Apoptosis and the target genes of microRNA-21

MicroRNA-21 (miR-21) is frequently up-regulated in cancer and the majority of its reported targets are tumor suppressors. Through functional suppression, miR-21 is implicated in practically every walk of oncogenic life: the promotion of cell proliferation, invasion and metastasis, genome instability and mutation, inflammation, replicative immortalization, abnormal metabolism, angiogenesis, and evading apoptosis, immune destruction, and growth suppressors. In particular, miR-21 is strongly involved in apoptosis. In this article, we reviewed the experimentally validated targets of miR-21 and found that two thirds are linked to intrinsic and/or extrinsic pathways of cellular apoptosis. This suggests that miR-21 is an Oncogene which plays a key role in resisting programmed cell death in cancer cells and that targeting apoptosis is a viable therapeutic option against cancers expressing miR-21.

Apoptosis and the target genes of microRNA-21

MicroRNA-21 (miR-21) is frequently up-regulated in cancer and the majority of its reported targets are tumor suppressors. Through functional suppression, miR-21 is implicated in practically every walk of oncogenic life: the promotion of cell proliferation, invasion and metastasis, genome instability and mutation, inflammation, replicative immortalization, abnormal metabolism, angiogenesis, and evading apoptosis, immune destruction, and growth suppressors. In particular, miR-21 is strongly involved in apoptosis. In this article, we reviewed the experimentally validated targets of miR-21 and found that two thirds are linked to intrinsic and/or extrinsic pathways of cellular apoptosis. This suggests that miR-21 is an oncogene which plays a key role in resisting programmed cell death in cancer cells and that targeting apoptosis is a viable therapeutic option against cancers expressing miR-21.