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Breast cancer (BC) is a common malignant tumor in women, and a considerable number of studies show that aberrant expression of miRNA is correlated with BC development. By analyzing TCGA-BRCA database through bioinformatics method, this study disclosed that miR-337-3p was significantly low in BC tissue and might be a cancer inhibitor in BC. To explore the effect and potential mechanism of miR-337-3p in BC, qRT-PCR was used in this study to indicate that the expression of miR-337-3p was downregulated in BC cells. Then, the effects of miR-337-3p on BC cells were detected by western blot, Cell Counting Kit-8 (CCK-8), wound healing and Transwell assays. After upregulating miR-337-3p expression, the cell viability, migration, invasion and epithelial-mesenchymal transition (EMT) of BC cells were markedly inhibited while cell apoptosis remarkably increased. Besides, it was predicted and identified by bioinformatics analysis and dual-luciferase assay that ESRP1 was a target gene of miR-337-3p. Finally, the progression and EMT of BC cells were promoted after upregulating ESRP1 expression level. However, upregulating miR-337-3p as well as ESRP1 reduced the promotion on the malignant phenotype of BC cells. This result revealed that miR-337-3p could inhibit ESRP1 expression to perform its biological functions. In conclusion, it was illustrated in this study that miR-337-3p is a tumor-inhibitor of BC and plays its regulatory role via its downstream gene ESRP1., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Programmed cell death 4 (PDCD4) is a tumor suppressor gene that inhibits tumor progression, invasion, and metastasis. Decreased PDCD4 expression is associated with poor prognosis in various types of cancers. We evaluated PDCD4 expression and its clinicopathologic correlation, including patient survival, in 289 surgically resected colorectal cancers. Low nuclear PDCD4 expression was identified in 177 (61.2%) cases and was associated with large tumor size, high pT classification, and the presence of lymphovascular and perineural invasion. The 5-year survival rate of patients with low nuclear PDCD4 expression was significantly lower than that of patients with high expression (72.2% vs. 93.3%, P<0.001). American Joint Committee on Cancer stage II and III colorectal cancer patients with low nuclear PDCD4 expression (76.9% and 67.2%, respectively) showed significantly worse overall survival than those with high expression (100% and 92.9%, P=0.002 and 0.032, respectively). Low nuclear PDCD4 expression was an independent poor prognostic factor in colorectal cancer patients (hazard ratio=3.556; 95% confidence interval, 1.739-7.271; P=0.001). Our study suggests that low PDCD4 expression is associated with aggressive behavior and can be used as a prognostic indicator of colorectal cancer patients., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

PA2G4 plays a dual role in tumors. However, the correlation of its expression with clinical feature and prognosis has never been reported in nasopharyngeal carcinoma (NPC). Using immunohistochemical staining, we examined PA2G4 protein level in clinicopathologically characterized 201 NPC cases (138 male and 63 female) with age ranging from 21 to 83 years and 45 nasopharyngeal (NP) tissues. Statistical methods were used to assess the difference in PA2G4 expression and its relationship with clinical parameters and prognosis in NPC. Immunohistochemical analysis showed that the protein expression of PA2G4 examined in NPC tissues was higher than that in the nasopharyngeal tissues (P=0.005). In addition, high levels of PA2G4 protein were positively correlated with tumor size (T classification) (P<0.001), the status of lymph node metastasis (N classification) (P<0.001), distant metastasis (P=0.029), and clinical stage (P<0.001) of NPC patients. Patients with higher PA2G4 expression had a significantly shorter overall survival time than did patients with low PA2G4 expression. Stratified analysis indicated that high expression of PA2G4 showed the inversed survival time in clinical stages III-IV, but not stages I-II. Finally, multivariate analysis suggested that the level of PA2G4 expression was an independent prognostic indicator (P<0.001) for the survival of patients with NPC. Elevated protein expression of PA2G4 was significantly shown, which plays an unfavorable outcome for NPC patient survival., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: Interferon-induced transmembrane protein 3 (IFITM3) is a key signaling molecule regulating cell growth in some tumors, but its function and mechanism in hepatocellular carcinoma (HCC) remain unknown. Our study investigated the relationship between the expression of IFITM3 and HCC development. Material and Methods . IFITM3 expression was identified via multiple gene expression databases and investigated in HCC tissue samples. Then, PLC/PRF/5 cells were transfected with lentivirus to knock down and overexpress the expression of IFITM3. IFITM3 expression, cell proliferation, and migration were detected by qRT-PCR, western blotting, QuantiGene Plex 2.0 assay, immunohistochemistry, CCK-8, and wound healing tests. RNA-seq technology identified the PI3K/AKT/mTOR pathway as an IFITM3-related signaling pathway for investigation., Results: IFITM3 expression was higher in HCC tissues than in adjacent normal tissues, and the level of IFITM3 was higher in HCC tissues with low differentiation and metastatic potential than in those with high/medium differentiation and without metastatic potential. A higher RNA level of IFITM3 was found in samples with IFITM3 rs12252-CC genotype rather than the TT genotype. Knockdown of IFITM3 in PLC/PRF/5 cells inhibited cell proliferation and migration, blocked the expression of the PI3K/AKT/mTOR signaling pathway, and decreased the expression of vimentin. The results were opposite with the overexpression of IFITM3., Conclusion: Upregulation of IFITM3 plays a role in the development of HCC. Possibly through regulating HCC cell proliferation and migration, these effects are associated with the PI3K/AKT/mTOR signaling pathway. Upregulation of IFITM3 is also associated with the IFITM3 rs12252-CC genotype., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2021 Yuli Hou et al.)

In addition to the deregulation of gene transcriptions and post-translational protein modifications, the aberrant translation from mRNAs to proteins plays an important role in the pathogenesis of various cancers. Targeting mRNA translation are expected to become potential approaches for anticancer treatments. Protein translation is affected by many factors including translation initiation factors and RNA-binding proteins. Recently, modifications of mRNAs mainly N6-methyladenine (m 6 A) modification and noncoding RNAs, such as microRNAs and long noncoding RNAs are involved. In this review, we generally summarized the recent advances on the regulation of protein translation by the interplay between mRNA modifications and ncRNAs. By doing so, we hope this review could offer some hints for the development of novel approaches in precision therapy of human cancers.

Dysregulation of long non-coding RNAs (lncRNAs) has been implicated in many cancer developments. Previous studies showed that lncRNA LINC00941 was aberrantly expressed in oral squamous cell carcinoma (OSCC). However, its role in OSCC development remains elusive. In this study, we demonstrated that in OSCC cells, EP300 activates LINC00941 transcription through up-regulating its promoter H3K27ac modification. Up-regulated LINC00941 in turn activates CAPRIN2 expression by looping to CAPRIN2 promoter. Functional assays suggest that both LINC00941 and CAPRIN2 play pivotal roles in promoting OSCC cell proliferation and colony formation. In vivo assay further confirmed the role of LINC00941 in promoting OSCC cell tumour formation. Lastly, we showed that the role of LINC00941 and CAPRIN2 in OSCC progression was mediated through activating the canonical WNT/β-catenin signaling pathway. Thus, LINC00941/CAPRIN2/ WNT/β-catenin signaling pathway provides new therapeutic targets for OSCC treatment., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Colon cancer has been well studied using a variety of molecular techniques, including whole genome sequencing. However, genetic markers that could be used to predict lymph node (LN) involvement, which is the most important prognostic factor for colon cancer, have not been identified. In the present study, we compared LN(+) and LN(-) colon cancer patients using differential gene expression and network analysis. Colon cancer gene expression data were obtained from the Cancer Genome Atlas and divided into two groups, LN(+) and LN(-). Gene expression networks were constructed using LASSO (Least Absolute Shrinkage and Selection Operator) regression. We identified hub genes, such as APBB1, AHSA2, ZNF767, and JAK2, that were highly differentially expressed. Survival analysis using selected hub genes, such as AHSA2, CDK10, and CWC22, showed that their expression levels were significantly associated with the survival rate of colon cancer patients, which indicates their possible use as prognostic markers. In addition, protein-protein interaction network, GO enrichment, and KEGG pathway analysis were performed with selected hub genes from each group to investigate the regulatory relationships between hub genes and LN involvement in colon cancer; these analyses revealed differences between the LN(-) and LN(+) groups. Our network analysis may help narrow down the search for novel candidate genes for the treatment of colon cancer, in addition to improving our understanding of the biological processes underlying LN involvement. All R implementation codes are available at journal website as Supplementary Materials.

miRNAs are key players in the integrated regulation of cellular processes and shape many of the functional properties that define the "cancer stem cell" (CSC) phenotype. Little is known, however, about miRNAs that regulate such properties in human colorectal carcinoma. In this study, we compared the expression levels of 754 miRNAs between paired samples of EpCAM + /CD44 + cancer cells (enriched in CSCs) and EpCAM + /CD44 neg cancer cells (with CSC depletion) sorted in parallel from human primary colorectal carcinomas and identified miR-221 as the miRNA that displayed the highest level of preferential expression in EpCAM + /CD44 + cancer cells. High levels of miR-221 expression were associated with Lgr5 + cells in mouse colon crypts and reduced survival in patients with colorectal carcinoma. Constitutive overexpression of miR-221 enhanced organoid-forming capacity of both conventional colorectal carcinoma cell lines and patient-derived xenografts (PDX) in vitro . Importantly, constitutive downregulation of miR-221 suppressed organoid-forming capacity in vitro and substantially reduced the tumorigenic capacity of CSC populations from PDX lines in vivo . Finally, the most abundant splicing isoform of the human Quaking ( QKI ) gene, QKI-5 , was identified as a functional target of miR-221; overexpression of miR-221-reduced QKI-5 protein levels in human colorectal carcinoma cells. As expected, overexpression of QKI-5 suppressed organoid-forming capacity in vitro and tumorigenic capacity of colorectal carcinoma PDX cells in vivo . Our study reveals a mechanistic link between miR-221 and QKI and highlights their key role in regulating CSC properties in human colorectal cancer. SIGNIFICANCE: These findings uncover molecular mechanisms underlying the maintenance of cancer stem cell properties in colon cancer. Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/20/5151/F1.large.jpg., (©2019 American Association for Cancer Research.)

G3BPs are members of an RNA-binding protein family and their aberrant expression is common in various cancers and there is growing evidence that G3BPs possess antiviral activities and are targeted by various viruses. G3BPs have also been implicated in both stabilization and degradation of specific mRNAs as well as translational control of mRNA targets. G3BPs have been shown to control translation of interferon-stimulated genes (ISGs), implying that G3BPs are involved in the regulation of the interferon system in response to viral infections and/or cellular stress. The interferon induced transmembrane (IFITM1, IFITM2 and IFITM3) proteins are antiviral proteins, and are also involved in cancer progression and metastasis. Therefore, these genes were selected in the studies reported here as potential transcript targets of G3BPs. Furthermore, G3BPs are involved in the regulation of the MEK pathway which also impacts on the translation of ISGs. Therefore, the role of this pathway was also analysed in regulation of IFITM1-3 proteins. Overall, this research study suggests that G3BPs are essential for the accumulation of IFITM1-3 proteins and intersect twice in the regulation of IFITM1-3 expression, first through MEK pathway and then through an interaction with the 3'-UTRs of its target transcripts. However, it is still to be determined whether the two apparent functions are part of a single control mechanism or the two functions are mutually exclusive.

Tumor cells and embryonic stem cells (ESCs) have similar transcription mechanisms. LIN28A is an important factor in tumor cells and ESCs, it is an inhibitor of intracellular endoplasmic reticulum (ER)‑related protein translation in ESCs. The present study aimed to examine the effects of LIN28A on an ER‑related protein, lysosome‑associated membrane glycoprotein 1 (LAMP1), in human bladder cancer cells and mouse (m)ESCs, using reverse transcription‑quantitative polymerase chain reaction and western blotting to detect the expression of LAMP1 mRNA and protein, respectively, following LIN28A knockdown. LIN28A was revealed to promote the proliferation, migration and invasion in human bladder cancer cells. These data suggested similarities between ESC cells and cancer cells and may provide novel ideas for the use of induced embryonic stem cell differentiation to treat tumors.

Many studies have shown that randomized clinical trial with long-term follow-up found no improvement in stage II esophageal carcinoma (EC) patients receiving preoperative neoadjuvant chemoradiotherapy or chemotherapy treatment, this limitation underscored the urgent need for novel and reliable biomarkers for prognosis and prediction in stage II EC. miR-21 is frequently over-expressed while programmed cell death 4 (PDCD4) is often down-regulated in solid tumors. This study aimed to investigate the clinicopathological and prognostic significance of miR-21 and PDCD4 expression and to elucidate any correlation between miR-21 and PDCD4 expression in stage II EC patients. The expression level of miR-21 was up-regulated while the PDCD4 protein was down-regulated in stage II EC tissues compared with the adjacent non-cancerous tissues. Analyses of the clinicopathological parameters indicated that miR-21 expression was associated with differentiation grade, T stage, and N stage. PDCD4 protein expression was associated with T stage, N stage, and tumor size. The univariate linear regression analysis suggested a significant negative correlation between miR-21 and PDCD4 expression. The Kaplan-Meier curve showed that high miR-21 expression or low PDCD4 expression predicted poor progression-free survival (PFS) and overall survival (OS) of patients with stag II EC. In conclusion, both up-regulated miR-21 and down-regulated PDCD4 expression were associated with the aggressive progression and poor prognosis of stage II EC. miR-21 and PDCD4 might be potential biomarkers of tumor progression and indicators of prognosis of stag II EC., (© 2018 Wiley Periodicals, Inc.)

Changes in mRNA splice patterns have been associated with key pathological mechanisms in prostate cancer progression. The androgen receptor (abbreviated AR) transcription factor is a major driver of prostate cancer pathology and activated by androgen steroid hormones. Selection of alternative promoters by the activated AR can critically alter gene function by switching mRNA isoform production, including creating a pro-oncogenic isoform of the normally tumour suppressor gene TSC2. A number of androgen-regulated genes generate alternatively spliced mRNA isoforms, including a prostate-specific splice isoform of ST6GALNAC1 mRNA. ST6GALNAC1 encodes a sialyltransferase that catalyses the synthesis of the cancer-associated sTn antigen important for cell mobility. Genetic rearrangements occurring early in prostate cancer development place ERG oncogene expression under the control of the androgen-regulated TMPRSS2 promoter to hijack cell behaviour. This TMPRSS2-ERG fusion gene shows different patterns of alternative splicing in invasive versus localised prostate cancer. Alternative AR mRNA isoforms play a key role in the generation of prostate cancer drug resistance, by providing a mechanism through which prostate cancer cells can grow in limited serum androgen concentrations. A number of splicing regulator proteins change expression patterns in prostate cancer and may help drive key stages of disease progression. Up-regulation of SRRM4 establishes neuronal splicing patterns in neuroendocrine prostate cancer. The splicing regulators Sam68 and Tra2β increase expression in prostate cancer. The SR protein kinase SRPK1 that modulates the activity of SR proteins is up-regulated in prostate cancer and has already given encouraging results as a potential therapeutic target in mouse models.

The formation of the mRNP complex is a critical component of translational regulation and mRNA decay. Both the 5' and 3'UTRs of CSF-1 mRNA are involved in post-transcriptional regulation. In CSF-1 mRNA, a small hairpin loop structure is predicted to form at the extreme 5' end (2-21nt) of the 5'UTR. Nucleolin binds the hairpin loop structure in the 5'UTR of CSF-1 mRNA and enhances translation, while removal of this hairpin loop nucleolin binding element dramatically represses translation. Thus in CSF-1 mRNA, the hairpin loop nucleolin binding element is critical for translational regulation. In addition, nucleolin interacts with the 3'UTR of CSF-1 mRNA and facilitates the miRISC formation which results in poly (A) tail shortening. The overexpression of nucleolin increases the association of CSF-1 mRNA containing short poly (A) n≤26 , with polyribosomes. Nucleolin both forms an mRNP complex with the eIF4G and CSF-1 mRNA, and is co-localized with the eIF4G in the cytoplasm further supporting nucleolin's role in translational regulation. The distinct foci formation of nucleolin in the cytoplasm of ovarian and breast cancer cells implicates the translational promoting role of nucleolin in these cancers., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Purpose: Musashi 2 (MSI2) is reported to be a potential oncoprotein in cases of leukemia and several solid tumors. However, its expression, function, and regulation in pancreatic ductal adenocarcinoma (PDAC) cases have yet to be demonstrated. Therefore, in the current study, we investigated the clinical significance and biologic effects of MSI2 expression in PDAC cases and sought to delineate the clinical significance of the newly identified Krüppel-like factor 4 (KLF4)/MSI2 regulatory pathway., Experimental Design: MSI2 expression and its association with multiple clinicopathologic characteristics in human PDAC specimens were analyzed immunohistochemically. The biological functions of MSI2 regarding PDAC cell growth, migration, invasion, and metastasis were studied using gain- and loss-of-function assays both in vitro and in vivo Regulation of MSI2 expression by KLF4 was examined in several cancer cell lines, and the underlying mechanisms were studied using molecular biologic methods., Results: MSI2 expression was markedly increased in both PDAC cell lines and human PDAC specimens, and high MSI2 expression was associated with poor prognosis for PDAC. Forced MSI2 expression promoted PDAC proliferation, migration, and invasion in vitro and growth and metastasis in vivo, whereas knockdown of MSI2 expression did the opposite. Transcriptional inhibition of MSI2 expression by KLF4 occurred in multiple PDAC cell lines as well as mouse models of PDAC., Conclusions: Lost expression of KLF4, a transcriptional repressor of MSI2 results in overexpression of MSI2 in PDACs, which may be a biomarker for accurate prognosis. A dysregulated KLF4/MSI2 signaling pathway promotes PDAC progression and metastasis. Clin Cancer Res; 23(3); 687-96. ©2016 AACR., Competing Interests: of Potential Conflicts of Interest: The authors declare no conflict of interest., (©2016 American Association for Cancer Research.)

Breast tumors contain tumorigenic cancer cells, termed "tumor-initiating cells" (TICs), which are capable of both replenishing themselves and giving rise to populations of nontumorigenic breast cancer cells (non-TICs). However, the molecular mechanisms responsible for breast tumor initiation remain poorly understood. Here we describe a chemical screening strategy to identify small molecules that enhance the effect of chemotherapeutic agents on TIC-enriched breast cancer cells. We identified proteins that interact with the lead compound C108, including the stress granule-associated protein, GTPase-activating protein (SH3 domain)-binding protein 2, G3BP2. G3BP2 regulates breast tumor initiation through the stabilization of Squamous cell carcinoma antigen recognized by T cells 3 (SART3) mRNA, which leads to increased expression of the pluripotency transcription factors Octamer-binding protein 4 (Oct-4) and Nanog Homeobox (Nanog). Our findings suggest that G3BP2 is important for the process of breast cancer initiation. Furthermore, these data suggest a possible connection between stress granule formation and tumor initiation in breast cancer cells., Competing Interests: I.G. received a commercial research grant from Sun Pharma Advanced Research Company. R.K.J. receives consultant fees from Ophthotech, Sun Pharma Advanced Research Company, SynDevRx, and XTuit and owns equity in Enlight Biosciences, Ophthotech, SynDevRx, and XTuit. R.K.J. also serves on the Board of Directors of XTuit and the Boards of Trustees of Tekla Healthcare Investors, Tekla Life Sciences Investors, Tekla Healthcare Opportunities Fund, and Tekla World Healthcare Fund.

Purpose: The aim of this study was to assess the role of the two markers, S100P and IMP3, in differentiating between pancreatic ductal adenocarcinoma (PDA) and non-neoplastic pancreatic tissue in (fine needle aspiration cytology) FNAC., Patients and Methods: This is a retrospective study that included 72 cases presented with pancreatic mass, where endoscopic guided FNAC was taken from pancreatic lesions. The final histopathologic diagnosis was considered the gold standard. Cell blocks were stained with anti S100P, and IMP3. Nuclear immunoreactivity with or without cytoplasmic staining for the first marker, and cytoplasmic staining for the second marker was considered specific. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and total accuracy of the two markers, as well as the combined accuracy of both markers were calculated., Results: S100P achieved 96.4% sensitivity, 93.3% specificity, 98.2% PPV, 87.5% NPV and 95.8% total accuracy, while IMP3 achieved 91.2% sensitivity, 86.7% specificity, 96.2% PPV, 72.2% NPV and 90.3% total accuracy for PDA. Both markers showed a total combined accuracy of 89%. S100P showed strong and diffuse staining pattern in most of cases, while the staining pattern for IMP3 was moderate and focal in most of cases., Conclusion: Both markers were sensitive and specific for diagnosis of PDA. The staining pattern for S100P was easier to evaluate than IMP3., (Copyright © 2016 National Cancer Institute, Cairo University. Production and hosting by Elsevier B.V. All rights reserved.)

Background: Dysregulation of microRNAs (miRNAs) has been found in human epithelial ovarian cancer (EOC). However, the role and mechanism of action of miR-23a in EOC remain unclear., Methods: The roles of miR-23a, IKKα, and ST7L in EOC were determined by MTT, colony formation, wounding healing, transwell, flow cytometry, immunofluorescence, RT-qPCR, and western blotting experiments. miR-23a target genes were validated by EGFP reporter assays, RT-qPCR, and western blotting analysis., Results: miR-23a is upregulated and promotes tumorigenic activity by facilitating the progress of cell cycle and EMT and repressing apoptosis in EOC cells. miR-23a enhances the expression of IKKα but suppresses the expression of ST7L by binding the 3'UTR of each transcript in EOC cells. The proliferation, migration, and invasion of EOC cells are increased by IKKα and inhibited by ST7L. Furthermore, miR-23a activates NF-κB by upregulating IKKα and WNT/MAPK pathway by downregulating ST7L., Conclusions: miR-23a functions as an oncogene by targeting IKKα and ST7L, thus contributing to the malignancy of EOC cells.

Purpose: Homeobox (HOX) transcription factors are critical regulators of cell fate, stem cell functions, and gastrointestinal development. They require three-amino acid loop extension (TALE) homeodomain proteins such as Meis1 to enhance their transcriptional efficiencies. There are complicated associations between different signaling pathways such as the Wnt and NOTCH and tumor progression. It has been investigated that GSK-3 as an important component of the Wnt pathway facilitates the expression of HOX target genes. Therefore, in the present study, we assessed the probable correlation between Wnt, NOTCH, and HOX genes in esophageal squamous cell carcinoma (ESCC) progression and metastasis through the correlational study between the Msi1 as an important activator for both of the NOTCH and Wnt pathways and Meis1., Methods: Levels of Meis1 and Msi1 messenger RNA (mRNA) expression in 51 ESCC patients were compared to the normal tissues using real-time polymerase chain reaction., Results: Only 3 out of 51 (5.9 %) cases had Meis1/Msi1 overexpression and also 3/51 (5.9 %) cases had Meis1/Msi1 underexpression. There was a significant correlation between the Msi1 and Mesi1 mRNA expression (p = 0.037). All of the Msi1/Meis1 underexpressed tumors were poorly differentiated (p = 0.003). Meis1 under/Msi1 overexpressed cases also were in T3 tumor depth of invasion (p = 0.019). And there was a significant correlation between the Msi1/Meis1 underexpression and gender (p = 0.045)., Conclusions: Our results show that Meis1 may have a positive feedback with Msi1 during the ESCC progression.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality worldwide. However, there is a shortage of suitable diagnostic markers for early stages of NSCLC, and therapeutic targets are limited. Right open reading frame (Rio) kinase 2 (RIOK2) and Nin one binding (NOB1) protein are important accessory factors in ribosome assembly and are highly expressed in malignant tumours; moreover, they interact with each other. However, the RIOK2 expression profile and its clinical significance as well as NOB1's mechanism in NSCLC remain unknown. In this study, NSCLC cell lines and 15 NSCLC tumour tissues (paired with adjacent normal lung tissues) were collected for a real-time quantitative PCR (RT-qPCR) analysis. In addition, 153 NSCLC cases and 27 normal lung tissues were used in an immunohistochemical analysis to evaluate the RIOK2 and NOB1 expression profiles, their clinicopathological factors in NSCLC and their correlations with prognoses. RIOK2 and NOB1 were highly expressed in NSCLC cells and tissues, and their expression profiles were significantly associated with the Tumour Node Metastasis (TNM) clinical stage, lymph node metastasis, and differentiation. RIOK2 expression was correlated with NOB1. The results suggested that simultaneously determining the expression of RIOK2 and NOB1 will improve the diagnostic rate in early stages of NSCLC. Moreover, RIOK2 and NOB1 might be potential targets for NSCLC therapy.

Nucleolin is a proliferation-associated protein that is overexpressed in multiple types of cancer. The mechanisms leading to overexpression of nucleolin in specific cancers are not fully understood. This study found that nucleolin is notably elevated in breast cancer cell lines MCF-7 and MDA-231 compared to nonmalignant breast epithelial MCF-10A cells. In silico analyses revealed the presence of putative binding sites for microRNAs miR-194 and miR-206 in the 3'-untranslated region (3'-UTR) of Ncl mRNA. Transfection of the three cell lines with pre-miR-194 or pre-miR-206 specifically decreased the Ncl mRNA and protein expression. Treatments of the cells with antagomiR-194 or antagomiR-206 upregulated nucleolin expression ~2- to 3-fold. Co-transfection of cells with a reporter vector containing the Ncl 3'-UTR downstream from the Renilla luciferase gene and pre-miR-194 or pre-miR-206 led to a ~3-fold decrease in Renilla/firefly luciferase activity. Cytoplasmic levels of the RNA-binding protein HuR were higher in MCF-7 and MDA-231 cells than those in MCF-10A cells. RNA immunoprecipitation assays demonstrated that HuR binds to Ncl mRNA in all the three cell types. ShRNA-mediated knock-down of HuR induced a decrease in nucleolin expression, while exogenous expression of HuR led to upregulation of nucleolin expression. Analysis of the polysome-monosome distribution of Ncl mRNA in HuR knock-down cells demonstrated that HuR enhances the translation efficiency of Ncl mRNA. These findings demonstrate that nucleolin expression is down-regulated by miR-194 and miR-206 and upregulated by HuR.

RNA-binding protein Lin28A is frequently over-expressed in human malignant tumors and is associated with tumor advance and poor prognosis. However, the expression pattern and functions of Lin28A in colon cancer are unknown. In this study, we detected the expression of Lin28A in colon cancer patients and tested the effect of Lin28A on the chemotherapeutic sensitivity of colon cancer cells to 5-fluorouracil (5-FU). As expected, we showed that Lin28A is up-regulated in 73.3 % of colon cancer patients. However, to our surprise, we found that oncogenic protein Lin28A-enforced expression in colon cancer cells enhanced the chemosensitivity of cancer cells to 5-FU via promoting the cell apoptosis. Further mechanisms study revealed that the effect of Lin28A increasing chemosensitivity of cancer cells is in a let-7 independent manner, but which is associated with decreasing the expression of DNA damage repair protein H2AX. Conclusively, here we reported an unexpected function of Lin28A, which may shed lights on fully understanding the physiological and pathological roles of this oncogene.

The RNA binding proteins RBM binding motif protein 38 (RBM38) and DEAD END 1 (DND1) selectively stabilize mRNAs by attenuating RNAse activity or protecting them from micro(mi)RNA-mediated cleavage. Furthermore, both proteins can efficiently stabilize the mRNA of the cell cycle inhibitor p21(CIP1). Since acute myeloid leukemia (AML) differentiation requires cell cycle arrest and RBM38 as well as DND1 have antiproliferative functions, we hypothesized that decreased RBM38 and DND1 expression may contribute to the differentiation block seen in this disease. We first quantified RBM38 and DND1 mRNA expression in clinical AML patient samples and CD34(+) progenitor cells and mature granulocytes from healthy donors. We found significantly lower RBM38 and DND1 mRNA levels in AML blasts and CD34(+) progenitor cells as compared to mature neutrophils from healthy donors. Furthermore, the lowest expression of both RBM38 and DND1 mRNA correlated with t(8;21). In addition, neutrophil differentiation of CD34(+) cells in vitro with G-CSF (granulocyte colony stimulating factor) resulted in a significant increase of RBM38 and DND1 mRNA levels. Similarly, neutrophil differentiation of NB4 acute promyelocytic leukemia (APL) cells was associated with a significant induction of RBM38 and DND1 expression. To address the function of RBM38 and DND1 in neutrophil differentiation, we generated two independent NB4RBM38 as well as DND1 knockdown cell lines. Inhibition of both RBM38 and DND1 mRNA significantly attenuated NB4 differentiation and resulted in decreased p21(CIP1) mRNA expression. Our results clearly indicate that expression of the RNA binding proteins RBM38 and DND1 is repressed in primary AML patients, that neutrophil differentiation is dependent on increased expression of both proteins, and that these proteins have a critical role in regulating p21(CIP1) expression during APL differentiation., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Higher Lin28 expression is associated with worse pathologic tumor responses in locally advanced gastric cancer patients undergoing neoadjuvant chemotherapy. However, the characteristics of Lin28 and its mechanism of action in chemotherapy resistance is still unclear. In this study, we found that transfection of Lin28 into gastric cancer cells (MKN45 and MKN28) increased their resistance to the chemo-drugs oxaliplatin (OXA), paclitaxel (PTX), doxorubicin (ADM), and fluorouracil (5-Fu) compared with gastric cancer cells transfected with a control vector. When knockdown Lin28 expression by Lin28 small interfering RNA (siRNA) was evaluated in vitro, we found that the resistance to chemo-drugs was reduced. Furthermore, we found that Lin28 up-regulates C-myc and P-gp and down-regulates Cylin D1. Finally, we found that miR-107 is a target microRNA of Lin28 and that it participates in the mechanism of chemotherapy resistance. Our results suggest that the Lin28/miR-107 pathway could be one of many signaling pathways regulated by Lin28 and associated with gastric cancer chemo-resistance.

Background: Our previous work found that serine/arginine-rich splicing factor 3 (SRSF3) was overexpressed in human ovarian cancer and the overexpression of SRSF3 was required for ovarian cancer cell growth and survival. The mechanism underlying the role of SRSF3 in ovarian cancer remains to be addressed., Methods: We conducted microarray analysis to profile the gene expression and splicing in SRSF3-knockdown cells and employed quantitative PCR and western blotting to validate the profiling results. We used chromatin immunoprecipitation to study transcription and the direct repeat green fluorescent protein reporter assay to study homologous recombination-mediated DNA repair (HRR)., Results: We identified 687 genes with altered expression and 807 genes with altered splicing in SRSF3-knockdown cells. Among expression-altered genes, those involved in HRR, including BRCA1, BRIP1 and RAD51, were enriched and were all downregulated. We demonstrated that the downregulation of BRCA1, BRIP1 and RAD51 expression was caused by decreased transcription and not due to increased nonsense-mediated mRNA decay. Further, we found that SRSF3 knockdown impaired HRR activity in the cell and increased the level of γ-H2AX, a biomarker for double-strand DNA breaks. Finally, we observed that SRSF3 knockdown changed splicing pattern of KMT2C, a H3K4-specific histone methyltransferase, and reduced the levels of mono- and trimethylated H3K4., Conclusion: These results suggest that SRSF3 is a new regulator of HRR process, which possibly regulates the expression of HRR-related genes indirectly through an epigenetic pathway. This new function of SRSF3 not only explains why overexpression of SRSF3 is required for ovarian cancer cell growth and survival but also offers a new insight into the mechanism of the neoplastic transformation.

Background: The aim of this study was to detect the expression of cold-inducible RNA-binding protein in pituitary adenoma and to determine its effects on tumor recurrence., Material/methods: We collected a total of 60 post-op samples collected from pituitary adenoma patients (including 20 cases of invasive pituitary adenoma, 20 cases of non-invasive adenoma, and 20 cases of non-invasive recurrent adenoma) admitted in our hospital. Both protein and mRNA levels of CIRP in 3 types of pituitary adenoma samples were quantified by Western blotting and real-time PCR, respectively., Results: Western blotting revealed significantly elevated CIRP expression levels in invasive pituitary adenoma compared to non-invasive tumors, with statistical significance (p<0.05). Recurrent pituitary adenoma expressed significantly higher CIRP levels compared to non-recurrent tumors (p<0.05). Real-time PCR for CIRP mRNA obtained consistent results: transcript levels were significantly higher in invasive pituitary adenoma compared to non-invasive adenoma (p<0.05); recurrent adenoma also had significantly higher CIRP mRNA levels compared to non-recurrent tumors (p<0.05). Among all 3 types of pituitary adenoma, recurrent tumors had the highest levels of CIRP mRNA and protein., Conclusions: The expression of CIRP in pituitary adenoma is closely related with tumor proliferation and invasion, and its significantly elevated expression level indicates post-op recurrence.

Background: Over-expression of insulin-like growth factor 2 mRNA binding protein 3 (IMP3) is correlated with poor prognosis in pancreatic ductal adenocarcinoma (PDAC). Previous studies examining other cancer types have implicated IMP3 in the regulation of several cellular functions that are characteristic of tumour cells. However, the role of this oncofetal protein in PDAC progression remained unclear., Methods: Using siRNA, we examined the effect of IMP3 inhibition on the motility, invasive ability, and matrix adhesion of PDAC cells. In addition, we also evaluated the expression of cytoskeleton-associated genes following IMP depletion., Results: Knockdown of IMP3 significantly decreased the motility, invasion, and extracellular matrix adhesion of select PDAC cells in vitro. In addition, IMP3-depleted cells exhibited lower levels of CD44 protein and KIF11 mRNA. Moreover, we also observed a reduction in downstream RhoA signaling following IMP3 knockdown, indicating that IMP3 modulates the levels of proteins involved in cytoskeletal organization., Conclusions: These results suggest that IMP3 facilitates PDAC progression by enhancing the pro-metastatic behaviour of tumour cells.

Insulin-like growth factor II mRNA-binding protein (IMP3) is an oncofetal protein involved in embryogenesis, which is expressed in a variety of malignant neoplasms. It is rarely expressed in normal adult tissue and benign tumors. The aim of this study was to evaluate the expression of IMP3 in benign and malignant serous tumors of the ovary. Seventy-nine ovarian tumors were examined for IMP3 expression by immunohistochemical analysis, comprising 16 benign serous tumors, 19 borderline serous tumors, and 44 serous carcinomas. Positive staining was defined as brown staining in the cytoplasm. Negative staining was defined as absent staining or staining of <5% of tumor cells. The intensity of staining (weak, moderate, and strong) and percentage (0% to 100%) of neoplastic cells staining positive for cytoplasmic IMP3 staining were recorded in each case. Moderate to strong cytoplasmic staining for IMP3 was observed in 30 of 44 (68%) serous carcinomas of the ovary; in contrast, <5% of the borderline and benign serous tumors expressed IMP3 ranging from weak to strong cytoplasmic staining. Statistically, the difference in IMP3 expression between these groups of tumors was highly significant (P<0.0001). Our findings demonstrate moderate to strong expression of IMP3 in the majority of ovarian serous carcinomas as compared with benign/borderline serous tumors, which demonstrated weak to strong expression in a small minority (<5%) of the tumors. Thus, IMP3 may be a useful adjunctive tool in the pathologic evaluation of ovarian serous tumors.

Initial steps in protein synthesis are highly regulated processes as they define the reading frame of the translation machinery. Eukaryotic translation initiation is a process facilitated by numerous factors (eIFs), aimed to form a "scanning" mechanism toward the initiation codon. Translation initiation of the main open reading frame (ORF) in an mRNA transcript has been reported to be regulated by upstream open reading frames (uORFs) in a manner of re-initiation. This mode of regulation is governed by the phosphorylation status of eIF2α and controlled by cellular stresses. Another mode of translational initiation regulation is leaky scanning, and this regulatory process has not been extensively studied. We have identified arsenite- inducible regulatory particle-associated protein (AIRAP) transcript to be translationally induced during arsenite stress conditions. AIRAP transcript contains a single uORF in a poor-kozak context. AIRAP translation induction is governed by means of leaky scanning and not re-initiation. This induction of AIRAP is solely dependent on eIF1 and the uORF kozak context. We show that eIF1 is phosphorylated under specific conditions that induce protein misfolding and have biochemically characterized this site of phosphorylation. Our data indicate that leaky scanning like re-initiation is responsive to stress conditions and that leaky scanning can induce ORF translation by bypassing poor kozak context of a single uORF transcript.

The role of programmed cell death 4 (PDCD4) in tumor biology is context-dependent. PDCD4 is described as a tumor suppressor, but its coexpression with protein arginine methyltransferase 5 (PRMT5) promotes accelerated tumor growth. Here, we report that PDCD4 is methylated during nutrient deprivation. Methylation occurs because of increased stability of PDCD4 protein as well as increased activity of PRMT5 toward PDCD4. During nutrient deprivation, levels of methylated PDCD4 promote cell viability, which is dependent on an enhanced interaction with eIF4A. Upon recovery from nutrient deprivation, levels of methylated PDCD4 are regulated by phosphorylation, which controls both the localization and stability of methylated PDCD4. This study reveals that, in response to particular environmental cues, the role of PDCD4 is up-regulated and is advantageous for cell viability. These findings suggest that the methylated form of PDCD4 promotes tumor viability during nutrient deprivation, ultimately allowing the tumor to grow more aggressively., (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)

The RNA-binding protein Lin28 is known to promote malignancy by inhibiting the biogenesis of let-7, which functions as a tumor suppressor. However, the role of the Lin28/let-7 axis in the epithelial-to-mesenchymal transition (EMT) and stemness in breast cancer has not been clearly expatiated. In our previous study, we demonstrated that let-7 regulates self-renewal and tumorigenicity of breast cancer stem cells. In the present study, we demonstrated that Lin28 was highly expressed in mesenchymal (M) type cells (MDA-MB-231 and SK-3rd), but it was barely detectable in epithelial (E) type cells (MCF-7 and BT-474). Lin28 remarkably induced the EMT, increased a higher mammosphere formation rate and ALDH activity and subsequently promoted colony formation, as well as adhesion and migration in breast cancer cells. Furthermore, we demonstrated that Lin28 induced EMT in breast cancer cells via downregulation of let-7a. Strikingly, Lin28 overexpression was found in breast cancers that had undergone metastasis and was strongly predictive of poor prognoses in breast cancers. Given that Lin28 induced the EMT via let-7a and promoted breast cancer metastasis, Lin28 may be a therapeutic target for the eradication of breast cancer metastasis.

Pituitary tumors belong to the group of most common neoplasms of the sellar region. Iodothyronine deiodinase types 1 (DIO1) and 2 (DIO2) are enzymes contributing to the levels of locally synthesized T3, a hormone regulating key physiological processes in the pituitary, including its development, cellular proliferation, and hormone secretion. Previous studies revealed that the expression of deiodinases in pituitary tumors is variable and, moreover, there is no correlation between mRNA and protein products of the particular gene, suggesting the potential role of posttranscriptional regulatory mechanisms. In this work we hypothesized that one of such mechanisms could be the alternative splicing. Therefore, we analyzed expression and sequences of DIO1 and DIO2 splicing variants in 30 pituitary adenomas and 9 non-tumorous pituitary samples. DIO2 mRNA was expressed as only two mRNA isoforms. In contrast, nine splice variants of DIO1 were identified. Among them, five were devoid of exon 3. In silico sequence analysis of DIO1 revealed multiple putative binding sites for splicing factor SF2/ASF, of which the top-ranked sites were located in exon 3. Silencing of SF2/ASF in pituitary tumor GH3 cells resulted in change of ratio between DIO1 isoforms with or without exon 3, favoring the expression of variants without exon 3. The expression of SF2/ASF mRNA in pituitary tumors was increased when compared with non-neoplastic control samples. In conclusion, we provide a new mechanism of posttranscriptional regulation of DIO1 and show deregulation of DIO1 expression in pituitary adenoma, possibly resulting from disturbed expression of SF2/ASF., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The protein insulin-like growth factor II mRNA binding protein 3 (IMP3) is an important factor for cell migration and adhesion in malignancies. Recent studies have shown a remarkable overexpression of IMP3 in different human malignant neoplasms and also revealed it as an important prognostic marker in some tumor entities. The purpose of this study is to compare IMP3 immunostaining in squamous cellular skin tumor and determine whether IMP3 can aid in the differential diagnosis of these lesions. To our knowledge, IMP3 expression has not been investigated in skin squamous cell proliferations thus far. Immunohistochemical staining for IMP3 was performed on slides organized by samples from 67 patients, 34 with keratoacanthoma and 33 with primary squamous cell carcinoma (16 invasive and 17 in situ). The majority of our KAs (25/34) were negative for IMP-3 staining. The majority of SCCs (19/33) are positive for IMP3 staining. The percentage of IMP3 positive cells increases significantly in group SCC (p=0.0111), and in particular in the SCC in situ group (p=0.0021) with respect to the KA group.  IMP3 intensity staining increases significantly in SCCs (p=0.0213), and particularly in SCCs (p=0.008) with respect to KA. Our data show that IMP3 expression is different in keratoacanthomas with respect to squamous cell carcinoma. IMP3 assessment and staining pattern, together with a careful histological study, can be useful in the differential diagnosis between KA e SCC.

The porcine oocyte and early embryo are transcriptionally quiescent following germinal vesicle breakdown in the oocyte and prior to activation of the embryonic genome, at approximately the 4-cell stage of development. Despite a lack of new transcription, mRNA and protein repertoires are subject to regulation during this time. One potential mechanism of regulation is through the functional activity of miRNAs and/or the presence of specific RNA-binding proteins. Both DND1 (dead end homolog 1) and FXR1 (fragile-X-mental retardation-related protein 1) are RNA-binding proteins that have been demonstrated to impact miRNA-mediated, post-transcriptional gene regulation. The objective was to characterize the presence and the expression changes in DND1 and FXR1 during pig oocyte maturation and early embryo development. DND1 and FXR1 expression were evaluated in oocytes and cumulus cells during meiotic progression and in 4-cell stage embryos using quantitative RT-PCR, Western blot analysis, and immunostaining. These data demonstrate DND1 and FXR1 mRNA are expressed in the maturing oocyte and early in vitro-fertilized embryos, with significantly less DND1 in 4-cell stage embryos as compared to germinal vesicle and metaphase II-arrested oocytes. Based on immunohistochemistry, DND1 protein abundance is greater in secondary follicles in comparison to primary and tertiary follicles. Using ribonucleoprotein immunoprecipitation from germinal vesicle-stage oocytes, DND1 was demonstrated to interact with several mRNAs associated with pluripotency. This work provides a better understanding of the biological relevance of DND1 and FXR1 during female gametogenesis and embryo development in pigs., (Copyright © 2012 Wiley Periodicals, Inc.)

Type I collagen is composed of two α1(I) polypeptides and one α2(I) polypeptide and is the most abundant protein in the human body. Expression of type I collagen is primarily controlled at the level of mRNA stability and translation. Coordinated translation of α(I) and α2(I) mRNAs is necessary for efficient folding of the corresponding peptides into the collagen heterotrimer. In the 5' untranslated region (5' UTR), collagen mRNAs have a unique 5' stem-loop structure (5' SL). La ribonucleoprotein domain family member 6 (LARP6) is the protein that binds 5' SL with high affinity and specificity and coordinates their translation. Here we show that RNA helicase A (RHA) is tethered to the 5' SL of collagen mRNAs by interaction with the C-terminal domain of LARP6. In vivo, collagen mRNAs immunoprecipitate with RHA in an LARP6-dependent manner. Knockdown of RHA prevents formation of polysomes on collagen mRNAs and dramatically reduces synthesis of collagen protein, without affecting the level of the mRNAs. A reporter mRNA with collagen 5' SL is translated three times more efficiently in the presence of RHA than the same reporter without the 5' SL, indicating that the 5' SL is the cis-acting element conferring the regulation. During activation of quiescent cells into collagen-producing cells, expression of RHA is highly up-regulated. We postulate that RHA is recruited to the 5' UTR of collagen mRNAs by LARP6 to facilitate their translation. Thus, RHA has been discovered as a critical factor for synthesis of the most abundant protein in the human body.

Insulin-like growth factor II mRNA binding protein 3 is an oncofetal protein that is expressed in multiple malignancies. This study aimed to determine the correlation of insulin-like growth factor II mRNA binding protein 3 expression with histologic grade of lung adenocarcinoma. Eighty-nine cases, including 11 atypical adenomatous hyperplasias, 10 pure bronchioloalveolar carcinomas, 36 well-differentiated adenocarcinomas and 41 moderately or poorly differentiated adenocarcinomas, were immunohistochemically studied using a monoclonal antibody against insulin-like growth factor II mRNA binding protein 3. Twenty-nine (70.7%) of 41 moderately to poorly differentiated adenocarcinomas were positive for insulin-like growth factor II mRNA binding protein 3, with 26 (89.7%) tumors demonstrating either a strong staining or staining in greater than 30% of tumor cells. Four (40.0%) of 10 bronchioloalveolar carcinomas and 13 (36.1%) of 36 well-differentiated adenocarcinomas exhibited insulin-like growth factor II mRNA binding protein 3 positivity with a variable degree and percentage of tumor cells staining. When bronchioloalveolar carcinomas were present in a pure form or as a component of adenocarcinomas, positive insulin-like growth factor II mRNA binding protein 3 staining was always patchy, with less than 20% of tumor cells stained. Overall, the frequency of positive insulin-like growth factor II mRNA binding protein 3 staining was lower in bronchioloalveolar carcinomas and well-differentiated adenocarcinomas compared to moderately/poorly differentiated adenocarcinomas (P < .01). No insulin-like growth factor II mRNA binding protein 3 signal was detected in any case of atypical adenomatous hyperplasia. These findings show that insulin-like growth factor II mRNA binding protein 3 is strongly and diffusely expressed in a large proportion of moderately/poorly differentiated lung adenocarcinomas, in particular in the solid component of mixed subtype adenocarcinomas, less frequently expressed in well-differentiated adenocarcinomas and bronchioloalveolar carcinomas, and negative in atypical adenomatous hyperplasias. The higher frequency of expression in moderately/poorly differentiated adenocarcinomas suggests that insulin-like growth factor II mRNA binding protein 3 expression may be associated with an aggressive biological behavior., (Copyright 2010 Elsevier Inc.)

Metallopanstimulin-1 (MPS-1) is a multifunctional ribosomal protein RPS27 that contains a zinc finger domain of the C(4) type. MPS-1 has been found to be increased in the sera of a number of different cancers, including head and neck squamous cell carcinoma (HNSCC). However, little is known about the effect of a high-level MPS-1 in regulating cancer cell behavior. In this study, we overexpressed MPS-1 protein in the HNSCC cell line UMSCC-1. We found MPS-1 distributes not only in the cytosol, but also in the nuclei. In addition, MPS-1 is secreted into the culture medium. In vitro and in vivo experiments show that growth of UMSCC-1 cells transfected with MPS-1 is dramatically inhibited. Moreover, we also found that with overexpressing MPS-1, UMSCC-1 cells were arrested on G0/G1 phase, cell proliferation rate was reduced, and tumor angiogenesis was impaired. Further gene array analysis, immunohistochemistry staining and Western blotting reveal that MPS-1 reduces paxillin mRNA and protein levels in UMSCC-1 cells both in vitro and in vivo. Together, these data indicate that when MPS-1 is overexpressed, it has an extraribosomal function as a strong inhibitor of HNSCC tumor cell growth, which may be exerted by reduced paxillin gene expression.

IMP-3 is a member of the insulin-like growth factor II mRNA binding protein (IMP) family of proteins that play a role in RNA trafficking and stabilization and cell growth and migration during embryogenesis but which are down-regulated in adult tissue. However, IMP-3 has recently been shown to be overexpressed in several epithelial malignancies, with increased expression correlating with aggressive behavior. To our knowledge, there is no published literature evaluating IMP-3 in lymphoid tissue. Accordingly, we immunohistochemically evaluated IMP-3 expression in normal lymphoid tissue and 141 lymphoid neoplasms. Physiologically, IMP-3 expression was restricted to germinal center B cells. Among lymphoid neoplasms, Hodgkin lymphoma demonstrated the highest percentage of positive cases (26/26, 100%) often with bright staining. Burkitt lymphoma was positive in 10 (83%) of 12 cases with moderate to bright staining. Although follicular lymphoma was also positive in a high percentage of cases (12/15, 80%), the intensity was exclusively weak to moderate. Although 22 (85%) of 26 of diffuse large B-cell lymphomas were positive for IMP-3, there was wide variability in staining intensity, which did not correlate with classification into activated B cell versus germinal center B origin. By contrast, lower proportions (8%-20%) of other non-germinal center B lymphoma subtypes were IMP-3-positive. In conclusion, although IMP-3 expression is seemingly restricted to physiologic germinal center B cells, its expression in lymphomas of germinal center B origin is less robust. However, there does appear to be some association with the latter group of lymphomas, which may prove to have diagnostic or therapeutic relevance as the biologic role of IMP-3 is further elucidated.

IMP3, an oncofetal protein, is a member of the insulin-like growth factor-II (IGF-II) mRNA-binding protein family. Its relevance as a novel biomarker in lung, pancreatic, renal, and cervical adenocarcinoma was recently revealed. However, its role in breast carcinogenesis and tumor progression is not yet established. Basal-like carcinoma was initially identified by gene expression profiling. It accounts for 15% to 30% of all breast cancers. These tumors express basal epithelial markers including cytokeratin 5 but lack expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2), therefore, are often referred to as triple negative breast cancer. They have been found to be associated with a worse overall and disease-free survival. In this retrospective study, we examined the IMP3 expression in invasive ductal carcinoma of the breast and correlated its expression with morphological and biologic prognostic factors. The study group comprised 138 cases of invasive ductal carcinoma retrieved from the surgical pathologic files for a 10-year period from 1997 to 2006. Survival data and clinical stage were available on all 138 patients. Tumor characteristics including size, grade, lymphovascular invasion, necrosis, lymph node metastasis, estrogen receptor, progesterone receptor, and HER2 status were obtained from pathologic reports. Immunohistochemistry was performed on formalin-fixed paraffin-embedded tissue using mouse monoclonal antibody against IMP3 and CK5/6. Of the 138 breast cancer cases, IMP3 expression was seen in 45 (33%). Twenty-five of the IMP3+ cases were triple negative. We found significant correlation between IMP3 expression and higher grade (P = .001), necrosis (P< .0001) triple negative, and CK5/6 expression (P < .0001 for each). Cox multivariate analysis showed a hazard ratio of IMP3 expression at 3.14 (P = .05). IMP3 is a novel biomarker for triple negative (basal-like) invasive mammary carcinoma, and its expression is associated with a more aggressive phenotype and decreased overall survival.

The oncofetal protein IMP3 (insulin-like growth factor II mRNA binding protein 3) is expressed during embryogenesis and carcinogenesis. Various tumor types have been analyzed for IMP3 expression, which was exclusively found in tumor cells and correlated with increased tumor aggressiveness and reduced overall survival. To our knowledge, IMP3 expression has not been investigated in bile duct carcinomas. Using large tissue sections from resection specimens of the extrahepatic biliary tract, we analyzed IMP3 in normal bile ducts (n = 36), bile ducts with acute inflammation and reactive epithelial changes (n = 26), low-grade dysplasia (n = 9), and high-grade dysplasia (n = 11). Furthermore, IMP3 expression was assessed in bile duct carcinoma (n = 115) using clinically well-characterized tissue microarrays. The findings were correlated with clinical-pathologic parameters including survival. High-grade dysplasia was strongly positive for IMP3 in all cases studied compared with no or weak expression in normal, inflamed, and low-grade dysplastic bile ducts. Of the bile duct carcinomas 58.3% (67/115) were strongly positive for IMP3, which was associated with a higher proliferation rate (P = .004) and p53 positivity (P = .022). Patients with strong IMP3 expression had significantly reduced overall survival (P = .037) similarly to the subgroup of pT3 carcinomas (P = .007). In multivariate analysis, IMP3 expression was an independent prognostic factor for overall survival (P = .040, RR = 1.809). This comprehensive study shows that IMP3 is an independent prognostic biomarker in bile duct carcinoma. In addition, it may be a marker for high-grade dysplasia in the extrahepatic biliary tract.

Insulin-like growth factor mRNA binding protein 3 (IMP3) is an mRNA-binding protein that regulates transcription of insulin-like growth factor II affecting cell proliferation during embryogenesis. It is highly expressed in carcinomas of the pancreas, stomach, colon, rectum, kidneys, uterine cervix, lung, and ovary. The purpose of our study was to evaluate IMP3 expression in thyroid follicular lesions, to determine whether it has a role in differentiating among these lesions, and to understand their biological relationships. We immunostained 219 thyroid lesions selected from our surgical pathology archives including 14 hyperplastic colloid nodules (CN), 19 Hashimoto's thyroiditis (HT), two Graves disease (GD), ten Hürthle cell adenoma (HCA), 20 follicular adenoma (FA), 37 conventional papillary thyroid carcinoma (PTC), 60 follicular variant of papillary carcinoma (FVPC), 19 Hürthle cell carcinoma (HCC), 32 follicular carcinoma (FC), and six poorly differentiated/anaplastic carcinoma. Immunohistochemistry was performed on formalin-fixed sections using monoclonal antibody to IMP3. Clinicopathological data were also reviewed. In all cases, residual thyroid tissue, CN, HT, GD, HCA, and FA were completely negative for IMP3 staining. Of the 60 FVPC, 23 tumors (38%) were positive for IMP3, with 13 of these (22%) showing very strong staining (3+). Of the 32 FC, 22 tumors (69%) were positive, with seven (22%) showing very strong staining (3+). Furthermore, 33 out of 37 cases (89%) of PTC were negative for IMP3. In all four PTC cases that did stain positive, staining was weak-moderate (1-2+). Similarly, 15 out of 19 cases (79%) of HCC were negative. No significant correlation was found between pathologic tumor characteristics and IMP3 expression in differentiated follicular pattern thyroid carcinoma. With 100% specificity and 69% sensitivity for FC as compared to FA and 100% specificity for FVPC, again compared to FA, IMP3 has the potential to be diagnostically useful in differentiating malignant and benign follicular pattern thyroid lesions. This study also points to a possible common biological relationship between FC and FVPC that requires further investigation.

Background: IMP3 (insulinlike growth factor II mRNA-binding protein 3) is a newly identified oncofetal RNA-binding protein that is involved in cell growth and cell migration during the early stages of embryogenesis. This study sought to elucidate its role in tumor progression and prognosis of colorectal adenocarcinoma (CRA)., Methods: IMP3 expression in 186 surgically resected unifocal primary CRAs was analyzed by immunohistochemistry. The proportions of tumor cells positive for IMP3 were scored into diffuse (> or =50%), focal or heterogeneous (10-50%), and trace (<10%), and the expression levels were correlated with clinicopathologic features and patient survival., Results: Cytoplasmic immunoreactivity for IMP3 was diffuse in 66 (35%), focal or heterogeneous in 38 (21%), and trace in 34 (18%) samples. No staining was seen in the adjacent nontumorous tissue. Diffuse IMP3 expression correlated with large tumor (>3 cm, P = .0452), high-stage tumor (IIIa-IV, P = .0417), lymph node metastasis (P = .0232), high lymph node ratio (LNR > or = .7, P = .0016), and lower 5-year survival (P = .0012). Further analysis showed that patients with high-stage CRA and diffuse IMP3 expression had the worst survival rate (P < .0001)-far worse than those without diffuse IMP3 expression (P = .0038). Moreover, multivariant analysis showed diffuse IMP3 expression, serosal invasion, LNR, tumor stage, and adjuvant chemotherapy were independent prognostic factors in CRA., Conclusion: Diffuse IMP3 protein expression correlates with invasion and aggressiveness during cancer growth and metastasis, and it is an important prognostic factor of CRAs.

Aim: To analyze the expressional variability of IMP3 between osteosarcoma and osteochondroma and explore its clinical significance., Methods: Paraffin sections from 68 patients with osteosarcoma and 20 patients with osteochondroma were examined for the expression of IMP3 by SP immunohistochemistry., Results: The negative, weak positive, moderate positive and strong positive expression rates of IMP3 in 68 patients with osteosarcoma were 4.41% (3/68), 22.06% (15/68), 22.74% (19/68), 45.59% (31/68), respectively, which were significantly higher than those in 20 cases of osteochondroma tissues (P<0.01). The positive expression of IMP3 in osteosarcoma was negative correlation with the 3-year survival rate of osteosarcoma patients after the operation (P<0.01)., Conclusion: The results suggest that IMP3 plays important roles in the tumorigenesis, progress and prognosis of osteosarcoma, and the expression of IMP3 may be an important feature of osteosarcoma.

Musashi1 (Msi1) is a highly conserved RNA-binding protein with pivotal functions in stem cell maintenance, nervous system development, and tumorigenesis. Despite its importance, only three direct mRNA targets have been characterized so far: m-numb, CDKN1A, and c-mos. Msi1 has been shown to affect their translation by binding to short elements located in the 3'-untranslated region. To better understand Msi1 functions, we initially performed an RIP-Chip analysis in HEK293T cells; this method consists of isolation of specific RNA-protein complexes followed by identification of the RNA component via microarrays. A group of 64 mRNAs was found to be enriched in the Msi1-associated population compared with controls. These genes belong to two main functional categories pertinent to tumorigenesis: 1) cell cycle, cell proliferation, cell differentiation, and apoptosis and 2) protein modification (including ubiquitination and ubiquitin cycle). To corroborate our findings, we examined the impact of Msi1 expression on both mRNA (transcriptomic) and protein (proteomic) expression levels. Genes whose mRNA levels were affected by Msi1 expression have a Gene Ontology distribution similar to RIP-Chip results, reinforcing Msi1 participation in cancer-related processes. The proteomics study revealed that Msi1 can have either positive or negative effects on gene expression of its direct targets. In summary, our results indicate that Msi1 affects a network of genes and could function as a master regulator during development and tumor formation.

The insulin-like growth factor-II mRNA-binding protein IMP3 plays an important role in embryogenesis and recent reports suggest an involvement in tumorigenesis. Although IMP3 expression has been well studied in mouse and human fetal and adult gonads, its role in ovarian cancer is unknown. We investigated the expression of IMP3 at protein and mRNA levels in a cohort of primary ovarian carcinomas and in 11 ovarian cancer cell lines. Western blot analysis revealed an expression of IMP3 in all ovarian cancer cell lines and immunohistochemistry demonstrated a positive cytoplasmic staining in 32 of 68 carcinomas (47%). In contrast, epithelium of borderline tumors, as well as, benign ovarian lesions and normal ovaries exhibited only weak or no IMP3 expression. In univariate Kaplan-Meier analysis, IMP3 protein expression was significantly associated with better overall survival (P=0.048). To confirm these findings, we further determined IMP3 mRNA expression in 43 ovarian cancer specimens by real time quantitative reverse transcription-polymerase chain reaction. A significant correlation between protein and mRNA levels (r=0.414, P=0.006), as well as a correlation of IMP3 mRNA expression with patient overall survival (P=0.044), was observed. Our results demonstrate that IMP3 is expressed in a subpopulation of ovarian cancer and a marker of good prognosis.

Clear cell carcinoma is an uncommon subtype of ovarian carcinoma, accounting for 10% of cases. Clear cell carcinoma typically presents with stage I or II disease, and in this setting prognostic markers could aid in management decisions, in particular the decision to treat with adjuvant chemotherapy. We tested whether expression of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3, also known as IMP3) can serve as a new biomarker to predict outcome for patients with clear cell carcinoma and other subtypes of ovarian carcinoma. The expression of IGF2BP3 was evaluated by immunohistochemistry in 475 ovarian carcinomas of different subtypes and correlated with disease-specific survival. IGF2BP3 antibody specificity was validated by correlation of IGF2BP3 protein with mRNA expression level in a series of 35 ovarian carcinomas (r=0.849, P<0.0001). IGF2BP3 protein expression was an independent marker of reduced disease-specific survival (risk ratio 2.9, 95% confidence interval 1.4-5.8) in the clear cell subtype (N=128), but not in high-grade serous (N=198) or endometrioid (N=121) carcinomas. The prognostic significance of IGF2BP3 expression for reduced disease-specific survival (risk ratio 2.6, 95% confidence interval 1.3-5.0) was confirmed in an independent series of cases (N=150) from three different centers in North America. We conclude that IGF2BP3 is the first biomarker of prognostic significance in ovarian clear cell carcinoma that has been validated in an independent case series.

Merkel cell carcinoma is an uncommon and aggressive primary cutaneous neuroendocrine carcinoma with a high rate of recurrence and metastasis. Optimal management is controversial; consequently, it is imperative to identify the signaling pathways involved in the pathogenesis of Merkel cell carcinoma so that effective therapeutic targeting agents can be developed. We previously reported that K homology domain-containing protein overexpressed in cancer is expressed in high-grade neuroendocrine carcinomas of the lung and extrapulmonary small cell carcinomas. The K homology domain-containing protein overexpressed in cancer (KOC), also known as L523S and IMP-3, is an insulin-like growth factor II messenger RNA-binding protein that promotes tumor cell proliferation by enhancing insulin-like growth factor II protein expression. Expression of KOC in Merkel cell carcinoma has not been investigated. We studied 20 Merkel cell carcinomas by immunohistochemistry using a monoclonal antibody against L523S/KOC. Of 20 Merkel cell carcinomas, 18 (90%) overexpressed KOC, with 11 (55%) overexpressing KOC in greater than 90% of tumor cells, 3 (15%) overexpressing KOC in 50% to 90% of tumor cells, 3 (15%) overexpressing KOC in 10% to 50% of tumor cells, and 1 (5%) overexpressing KOC in less than 10% of tumor cells. The immunostaining intensity was variable, with moderate to strong staining in 14 cases and weak staining in the remaining 4. Extent of expression of K homology domain-containing protein overexpressed in cancer predicted metastasis (P = .04) and was weakly correlated with increased tumor size (P = .08). In conclusion, Merkel cell carcinoma expresses K homology domain-containing protein overexpressed in cancer with an expression pattern similar to high-grade neuroendocrine carcinomas of the lung and extrapulmonary small cell carcinomas. We propose K homology domain-containing protein overexpressed in cancer as a potential target molecule for the treatment of high-grade neuroendocrine carcinomas, irrespective of anatomical location, and a potential marker to predict metastatic disease.

Endothelial monocyte-activating polypeptide II (EMAP-II) is an inflammatory cytokine with chemotactic activity. Because the dental follicle (DF) recruits mononuclear cells (osteoclast precursors) to promote the osteoclastogenesis needed for tooth eruption, it was the aim of this study to determine if EMAP-II contributes to this recruitment. Using a DNA microarray, EMAP-II was found to be highly expressed in vivo in the DFs of day 1 to day 11 postnatal rats, with its expression elevated on days 1 and 3. Use of a short interfering RNA (siRNA) to knock down EMAP-II expression resulted in a reduction in the expression of colony-stimulating factor-1 (CSF-1) and monocyte chemoattractant protein-1 (MCP-1) in the DF cells. Addition of EMAP-II protein to the DF cells partially restored the expression of CSF-1 and MCP-1. In chemotaxis assays using either conditioned medium of the DF cells with anti-(EMAP-II) immunoglobulin G added or conditioned medium of DF cells with EMAP-II knocked down by siRNA, migration indexes of bone marrow mononuclear cells were significantly reduced. These results suggest that EMAP-II is another chemotactic molecule in the dental follicle involved in the recruitment of mononuclear cells, and that EMAP-II may exert its chemotactic function directly by recruiting mononuclear cells and indirectly by enhancing the expression of other chemotactic molecules (CSF-1 and MCP-1).