miR-1301 promotes prostate cancer proliferation through directly targeting PPP2R2C

Establishment of a circRNA-regulated E3 ubiquitin ligase signature and nomogram to predict immunotherapeutic efficacy and prognosis in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a common type of malignant tumor where the prognosis is dismal. Circular RNA (CircRNA) is a novel RNA that regulates downstream gene transcription and translation to influence the progression of HCC. However, the regulatory relationship that exists between E3 ligases, which is a class of post-translational modifying proteins, and circRNA remains unclear.

METHODS

Based on the E3 ubiquitin ligase in the competitive endogenous RNA (ceRNA) network, a circRNA-regulated E3 ubiquitin ligase signature (CRE3UL) was developed. A CRE3UL signature was created using the least absolute shrinkage and selection operator (Lasso) and Cox regression analysis and merged it with clinicopathologic characteristics to generate a nomogram for prognosis prediction. The pRRophetic algorithm was utilized and immunological checkpoints were analyzed to compare the responses of patients in the high-risk group (HRG) and low-risk group (LRG) to targeted therapy and immunotherapy. Finally, experimental research will further elucidate the relationship between E3 ubiquitin ligase signature and HCC.

RESULTS

HRG patients were found to have a worse prognosis than LRG patients. Furthermore, significant variations in prognosis were observed among different subgroups based on various clinical characteristics. The CRE3UL signature was identified as being an independent prognostic indicator. The nomogram that combined clinical characteristics and the CRE3UL signature was found to accurately predict the prognosis of HCC patients and demonstrated greater clinical utility than the current TNM staging approach. According to anticancer medication sensitivity predictions, the tumors of HRG patients were more responsive to gefitinib and nilotinib. From immune-checkpoint markers analysis, immunotherapy was identified as being more probable to assist those in the HRG.

CONCLUSIONS

We found a significant correlation between the CRE3UL signature and the tumor microenvironment, enabling precise prognosis prediction for HCC patients. Additionally, a nomogram was developed that performs well in predicting the overall survival (OS) of HCC patients. This provides valuable guidance for clinicians in devising specific personalized treatment strategies.

miR-1301-3p promotes invasion and migration and EMT progression in esophageal cancer by downregulating NBL1 expression

BACKGROUND

Esophageal cancer (ESCA) is one of the most aggressive and lethal human malignant cancers. MicroRNA-1301-3p (miR-1301-3p) plays vital roles in a majority of malignancies. The aim of this study was to investigate the role of miR-1301-3p/NBL1 axis on ESCA cell invasion, migration, epithelial-mesenchymal transition (EMT) process, as well as its association with prognosis of ESCA patients.

METHODS

The expression levels of miR-1301-3p and NBL1 were predicted by bioinformatics and further verified by RT-qPCR assays. Kaplan-Meier (K-M) plotter analysis and univariate and multivariate Cox analyses were used to evaluate the relationship between miR-1301-3p and clinicopathological variables and prognosis. The role of miR-1301-3p on cell invasion, migration was detected by transwell invasion, and wound healing assays, respectively. The EMT-related proteins were detected by western blot. The target genes and the target binding sites were predicted by bioinformatics and further determined by RT-qPCR assay.

RESULTS

MiR-1301-3p was remarkably upregulated in ESCA tissues and cells, and its high expression was associated with poor prognosis of ESCA. Overexpression of miR-1301-3p promoted ESCA cell invasion, migration and mediated EMT process in vitro, whereas knockdown of miR-1301-3p showed the opposite effects. Moreover, NBL1 was predicted as a target gene of miR-1301-3p. NBL1 was lowly expressed in ESCA cells and significantly decreased after upregulation of miR-1301-3p. Meanwhile, we found that low expression of NBL1 was significantly associated with poor prognosis of ESCA patients.

CONCLUSION

MiR-1301-3p is a potential biomarker for predicting the prognosis of ESCA patients. It may promote ESCA invasion, migration and EMT progression by regulating NBL1 expression.

PRDM16, Negatively Regulated by miR-372-3p, Suppresses Cell Proliferation and Invasion in Prostate Cancer

Prostate cancer (PCa) is one of the most prevalent malignant tumors. The alternation of microRNA (miRNA) expression is associated with prostate cancer progression, whereas its way to influence progression of prostate cancer remains elusive. The expression levels of PRDM16 mRNA and miR-372-3p in PCa cell lines were analyzed using qRT-PCR. The protein expression of PRDM16 in PCa cell lines was also analyzed using western blot. CCK-8, wound healing, and Transwell assays were applied to examine cell proliferation, migration, and invasion in prostate cancer cells, respectively. Dual-luciferase reporter assay was utilized to validate the interaction between miR-372-3p and PRDM16. In the present study, markedly decreased PRDM16 mRNA and protein expression levels were observed in prostate cancer cells. PRDM16 overexpression hampered cellular proliferation, migration, and invasion, while silencing PRDM16 had the opposite effect. Moreover, miR-372-3p could target the regulation expression of PRDM16. Rescue experiments demonstrated that upregulating miR-372-3p conspicuously restored the inhibitory effect of increased PRDM16 on cell proliferation, migration, and invasion in PCa. Overall, our study clarifies the biological role of miR-372-3p/PRDM16 axis in prostate cancer progression, which may be effective biomarkers for clinical treatment of prostate cancer.

PRDM16, negatively regulated by miR-372-3p, suppresses cell proliferation and invasion in prostate cancer

Prostate cancer (PCa) is one of the most prevalent malignant tumours. The alternation of microRNAs (miRNAs) expression is associated with prostate cancer progression, whereas its way to influence progression of prostate cancer remains elusive. The expression levels of PRDM16 mRNA and miR-372-3p in PCa cell lines were analysed using qRT-PCR. The protein expression of PRDM16 in PCa cell lines was also analysed using Western blot. CCK-8, wound healing and Transwell assays were applied to examine cell proliferation, migration, and invasion in prostate cancer cells, respectively. Dual-luciferase reporter assay was utilised to validate the interaction between miR-372-3p and PRDM16. In the present study, markedly decreased PRDM16 mRNA and protein expression levels were observed in prostate cancer cells. PRDM16 overexpression hampered cellular proliferation, migration, and invasion, while silencing PRDM16 had the opposite effect. Moreover, miR-372-3p could target the regulation expression of PRDM16. Rescue experiments demonstrated that upregulating miR-372-3p conspicuously restored the inhibitory effect of increased PRDM16 on cell proliferation, migration, and invasion in PCa. Overall, our study clarifies the biological role of miR-372-3p/PRDM16 axis in prostate cancer progression, which may be effective biomarkers for clinical treatment of prostate cancer.

Aberrant Expression of miR-1301 in Human Cancer

miR-1301 is a newly discovered miRNA, which is abnormally expressed in 14 types of tumors. miR-1301 inhibits 23 target genes, forms a ceRNA network with 2 circRNAs and 8 lncRNAs, and participates in 6 signaling pathways, thereby affecting tumor cell proliferation, invasion, metastasis, apoptosis, angiogenesis, etc. Abnormal expression of miR-1301 is often associated with poor prognosis of cancer patients. In addition, miR-1301 is related to the anti-tumor effect of epirubicin on osteosarcoma and imatinib on chronic myeloid leukemia(CML) and can enhance the cisplatin sensitivity of ovarian cancer. This work systematically summarizes the abnormal expression and prognostic value of miR-1301 in a variety of cancers, depicts the miR-1301-related signaling pathways and ceRNA network, and provides potential clues for future miR-1301 research.

Aberrant expression of five miRNAs in papillary thyroid carcinomas

BACKGROUND

The miRNAs play critical roles in the progression of various tumors. Our study aimed to screen and identify miRNAs to investigate their diagnostic and prognostic value for papillary thyroid carcinoma (PTC).

METHODS

miRNAs were evaluated in PTC (n = 30) tissues, A-PTC (n = 30), benign nodules (n = 35) and A-benign nodules (n = 35). The expression levels of five miRNAs were quantified using real-time, quantitative PCR. ROC analysis was used to evaluate the miRNA diagnostic value.

RESULTS

The expression of miR-1296-5p, miR-1301-3p, and miR-532-5p was significantly downregulated (p = 0.0001, p = 0.0006, p = 0.0024, respectively), while miR-551b-3p and miR-455-3p were significantly upregulated in PTC tissues compared to A-PTC tissues (p = 0.0005, p = 0.0046, respectively). Interestingly, the expression of miR-1296-5p was downregulated, while miR-551b-3p and miR-455-3p were upregulated in the A-PTC group compared to the A-benign group. Moreover, the miR-1296-5p expression level was associated with tumor size, the number of foci and the TNM stage; the miR-455-3p expression level was correlated with patient age, tumor size, and TNM stage; and the miR-532-5p expression level was correlated with patient age, lymph node metastasis and TNM stage correspondingly. ROC analysis revealed that the AUCs for miR-1301-3p, miR-1296-5p, miR-455-3p, miR-532-5p, and miR-551b-3p were 0.773, 0.790, 0.783, 0.744, and 0.650, respectively.

CONCLUSIONS

Our results indicated that miR-1296-5p, miR-1301-3p, miR-532-5p, miR-551b-3p, and miR-455-3p are aberrantly expressed in papillary thyroid carcinomas and correlated with clinicopathological features. ROC curve analysis indicated that these five miRNAs have a potential diagnostic value. Consequently, we speculate that the five altered miRNAs may serve as potential diagnostic and prognostic biomarkers for PTC.

Decreased level of miR-1301 promotes colorectal cancer progression via activation of STAT3 pathway

The molecular pathogenesis of colorectal cancer (CRC) has been widely investigated in recent years. Accumulating evidence has indicated that microRNA (miRNA) dysregulation participates in the processes of driving CRC initiation and progression. Aberrant expression of miR-1301 has been found in various tumor types. However, its role in CRC remains to be elucidated. In the present study, we identified miR-1301 was enriched in normal colorectal tissues and significantly down-regulated in CRC. Decreased level of miR-1301 strongly correlated with aggressive pathological characteristics, including advanced stage and metastasis. Bioinformatics and dual luciferase assay demonstrated that STAT3 is a direct target of miR-1301. Gain and loss-of-function assays showed that miR-1301 had no effect on cell proliferation. Overexpression of miR-1301 suppressed cell migration and invasion capacity of pSTAT3-positive LoVo cells, but not pSTAT3-negative SW480 cells, while inhibition of miR-1301 consistently promoted cell migration and invasion in both cell lines. Additionally, miR-1301 inhibition restored the suppressed migration and invasion of STAT3-knockdown LoVo cells. MiR-1301 functioned as a tumor suppressor to modulate the IL6/STAT3 signaling pathway. In summary, this study highlights the significant role of miR-1301/STAT3 axis in CRC metastasis.

miR-1301-3p Promotes Cell Proliferation and Facilitates Cell Cycle Progression via Targeting SIRT1 in Gastric Cancer

So far, many existing evidences indicate that microRNAs (miRNA) are closely associated with the tumorigenesis and progression of various tumors. It has been reported that miR-1301-3p is abnormally expressed in several malignant tumors. However, the role of miR-1301-3p in gastric cancer (GC) remains unclear and is worth studying. Through qRT-PCR, the expression of miR-1301-3p and SIRT1 were detected in GC tissues and cells. The cell proliferation and cell cycle were measured through CCK-8 assay and clone formation assay. Dual luciferase reporter assay was used to determine the target of miR-1301-3p. Though tumorigenesis assay, we monitored the effect of miR-1301-3p on GC cell growth in vivo. miR-1301-3p was upregulated in GC tissues and cells in our study. Overexpression of miR-1301-3p accelerated GC cell proliferation, cell cycle progression and tumorigenesis. Notably, altering the expression miR-1301-3p caused deregulation of Cyclin D1, CDK4, c-Myc and P21. Furthermore, SIRT1 was the direct target of miR-1301-3p by luciferase reporter assay. After transfecting with miR-1301-3p inhibitor, we found that knockdown of SIRT1 could enhance the ability of proliferation. Our results identify miR-1301-3p as a novel potential therapeutic target that is associated with the tumorigenesis and progression of gastric cancer.

The long non-coding RNA GHSROS reprograms prostate cancer cell lines toward a more aggressive phenotype

It is now appreciated that long non-coding RNAs (lncRNAs) are important players in orchestrating cancer progression. In this study we characterized GHSROS, a human lncRNA gene on the opposite DNA strand (antisense) to the ghrelin receptor gene, in prostate cancer. The lncRNA was upregulated by prostate tumors from different clinical datasets. Transcriptome data revealed that GHSROS alters the expression of cancer-associated genes. Functional analyses in vitro showed that GHSROS mediates tumor growth, migration and survival, and resistance to the cytotoxic drug docetaxel. Increased cellular proliferation of GHSROS-overexpressing PC3, DU145, and LNCaP prostate cancer cell lines in vitro was recapitulated in a subcutaneous xenograft model. Conversely, in vitro antisense oligonucleotide inhibition of the lncRNA reciprocally regulated cell growth and migration, and gene expression. Notably, GHSROS modulates the expression of PPP2R2C, the loss of which may drive androgen receptor pathway-independent prostate tumor progression in a subset of prostate cancers. Collectively, our findings suggest that GHSROS can reprogram prostate cancer cells toward a more aggressive phenotype and that this lncRNA may represent a potential therapeutic target.

miR-1301-3p promotes the proliferation and migration of lung cancer cells via direct repression of polymerase I and transcript release factor

Aberrant expression of microRNAs (miRNAs or miRs) is associated with a number of human diseases, including lung cancer. Although numerous differentially expressed miRNAs have been identified in lung cancer via microarray and sequencing methods, to the best of our knowledge, only a small portion of these miRNAs have been experimentally verified. In the present study, miR-1301-3p expression levels in lung tumor tissues and lung cancer cells were measured by reverse transcription-quantitative PCR (RT-qPCR) and by analyzing previously published data. Cell Counting Kit-8 and Transwell assays were used to analyze the function of miR-1301-3p in lung cancer tissues and cells. Bioinformatics analysis, RT-qPCR, western blotting and a dual-luciferase reporter assay were performed to investigate the mechanism of miR-1301-3p in lung cancer cells. It was identified that miR-1301-3p is an upregulated miRNA in lung cancer via analyzing previously published microarray and The Cancer Genome Atlas-lung squamous cell carcinoma project data, and the upregulation of miR-1301-3p was confirmed in collected clinical samples and cells. Inhibition of miR-1301-3p suppressed lung cancer cell proliferation and migration. In addition, miR-1301-3p inhibition upregulated E-cadherin, an epithelial cell maker, and downregulated vimentin, a mesenchymal cell marker. Using bioinformatics analysis, it was revealed that polymerase I and transcript release factor (PTRF) is a target of miR-1301-3p. RT-qPCR, western blotting and dual-luciferase reporter assays demonstrated that PTRF is targeted by miR-1301-3p in lung cancer cells. The rescue experiments indicated that silencing PTRF could attenuate the inhibition of cell proliferation and migration induced by miR-1301-3p inhibitor in lung cancer cells. Furthermore, a strong negative correlation between miR-1301-3p and PTRF mRNA was identified in clinical samples. In summary, the present data highlight the involvement of miR-1301-3p in the proliferation and migration of lung cancer cells, indicating that miR-1301-3p may be a promising biomarker for lung cancer.

Redox inhibition of protein phosphatase PP2A: Potential implications in oncogenesis and its progression

Cellular processes are dictated by the active signaling of proteins relaying messages to regulate cell proliferation, apoptosis, signal transduction and cell communications. An intricate web of protein kinases and phosphatases are critical to the proper transmission of signals across such cascades. By governing 30–50% of all protein dephosphorylation in the cell, with prominent substrate proteins being key regulators of signaling cascades, the phosphatase PP2A has emerged as a celebrated player in various developmental and tumorigenic pathways, thereby posing as an attractive target for therapeutic intervention in various pathologies wherein its activity is deregulated. This review is mainly focused on refreshing our understanding of the structural and functional complexity that cocoons the PP2A phosphatase, and its expression in cancers. Additionally, we focus on its physiological regulation as well as into recent advents and strategies that have shown promise in countering the deregulation of the phosphatase through its targeted reactivation. Finally, we dwell upon one of the key regulators of PP2A in cancer cells-cellular redox status-its multifarious nature, and its integration into the reactome of PP2A, highlighting some of the significant impacts that ROS can inflict on the structural modifications and functional aspect of PP2A.

PRC2 targeting is a therapeutic strategy for EZ score defined high-risk multiple myeloma patients and overcome resistance to IMiDs

BACKGROUND

Multiple myeloma (MM) is a malignant plasma cell disease with a poor survival, characterized by the accumulation of myeloma cells (MMCs) within the bone marrow. Epigenetic modifications in MM are associated not only with cancer development and progression, but also with drug resistance.

METHODS

We identified a significant upregulation of the polycomb repressive complex 2 (PRC2) core genes in MM cells in association with proliferation. We used EPZ-6438, a specific small molecule inhibitor of EZH2 methyltransferase activity, to evaluate its effects on MM cells phenotype and gene expression prolile.

RESULTS

PRC2 targeting results in growth inhibition due to cell cycle arrest and apoptosis together with polycomb, DNA methylation, TP53, and RB1 target genes induction. Resistance to EZH2 inhibitor is mediated by DNA methylation of PRC2 target genes. We also demonstrate a synergistic effect of EPZ-6438 and lenalidomide, a conventional drug used for MM treatment, activating B cell transcription factors and tumor suppressor gene expression in concert with MYC repression. We establish a gene expression-based EZ score allowing to identify poor prognosis patients that could benefit from EZH2 inhibitor treatment.

CONCLUSIONS

These data suggest that PRC2 targeting in association with IMiDs could have a therapeutic interest in MM patients characterized by high EZ score values, reactivating B cell transcription factors, and tumor suppressor genes.

MicroRNA-1301 inhibits migration and invasion of osteosarcoma cells by targeting BCL9

Increasing reports demonstrated that miRNAs play a critical role in tumor development and progression. Previous studies revealed that miR-1301 was abnormally expressed in various cancers. However, its function and underlying mechanism in osteosarcoma (OS) remains unknown. In this study, miR-1301 expression was significantly down-regulated in both OS tissues and cell lines. Down-regulated miR-1301 was obviously associated with malignant clinical features and poor overall survival of OS patients. miR-1301 overexpression inhibited cell proliferation, migration and invasion. In addition, we identified BCL9 act as a direct target of miR-1301 by directly binding to its 3'-UTR. In clinical OS tissues, miR-1301 negatively correlated BCL9 expression. BCL9 was up-regulated in OS tissues and cells. BCL9 overexpression promoted OS progression. Moreover, restoration of BCL9 expression at least partially abolished the proliferation, migration and invasion of miR-1301 on OS cells. In conclusion, our data indicated that miR-1301 inhibited cell proliferation, migration and invasion of OS by targeting BCL9, and may represent a novel potential therapeutic target and prognostic marker for OS.

miR-1301-3p promotes prostate cancer stem cell expansion by targeting SFRP1 and GSK3β

Cancer stem cells promote tumor progression, drug-resistance, and relapse, and many microRNAs (miRNAs) play critical roles in the expansion of cancer stem cells. In the present study, we investigated the role of miR-1301-3p in the expansion of prostate cancer stem cells; miR-1301-3p was significantly upregulated in prostate cancer cells and tissues compared with normal prostate cells and tissues. Sphere formation and side population assays suggested that miR-1301-3p promoted the expansion of prostate cancer stem cells, and increased the expression of prostate cancer stem cell-associated genes, such as OCT4, SOX2, NANOG, CD44, KLF4, c-MYC, and MMP2. MiR-1301-3p targeted Wnt pathway inhibitors, GSK3β and SFRP1, and inhibited their expression by directly binding to their 3' untranslated regions. TOP/FOP luciferase assays suggested that miR-1301-3p activated the Wnt pathway, which was confirmed by increased β-catenin expression in the nucleus. Furthermore, the miR-1301-3p level correlated negatively with GSK3β and SFRP1 in prostate cancer tissues. In summary, we found that miR-1301-3p promoted the expansion of prostate cancer stem cells by inhibiting GSK3β and SFRP1, and activating the Wnt pathway.

Assessing the functional association of intronic miRNAs with their host genes

In human, nearly half of the known microRNAs (miRNAs) are encoded within the introns of protein-coding genes. The embedment of these miRNA genes within the sequences of protein-coding genes alludes to a possible functional relationship between intronic miRNAs and their hosting genes. Several studies, using predicted targets, suggested that intronic miRNAs influence their hosts' function either antagonistically or synergistically. New experimental data of miRNA expression patterns and targets enable exploring this putative association by relying on actual data rather than on predictions. Here, our analysis based on currently available experimental data implies that the potential functional association between intronic miRNAs and their hosting genes is limited. For host-miRNA examples where functional associations were detected, it was manifested by either autoregulation, common targets of the miRNA and hosting gene, or through the targeting of transcripts participating in pathways in which the host gene is involved. This low prevalence of functional association is consistent with our observation that many intronic miRNAs have independent transcription start sites and are not coexpressed with the hosting gene. Yet, the intronic miRNAs that do show functional association with their hosts were found to be more evolutionarily conserved compared to other intronic miRNAs. This might suggest a selective pressure to maintain this architecture when it has a functional consequence.

EZH2 induces the expression of miR-1301 as a negative feedback control mechanism in triple negative breast cancer

Breast cancer is one of the most common malignancies in women. ERα, PR, and HER2 triple negative breast cancer (TNBC) is the current research focus because of the lack of effective targeted therapies. In our study, lentivirus systems were used to overexpress EZH2 and miR-1301 in TNBC cell lines. Western blot analysis and RT-qPCR were used to detect the protein and microRNA levels. The TCGA and Kaplan Meier plotter databases were used to analyze the EZH2 and miR-1301 expression levels in breast cancer. The effect of miR-1301 overexpression on cell proliferation, migration and colony formation were determined by using the sulforhodamine B (SRB) assay, wound healing assay and colony formation assay, respectively. Furthermore, an xenograft mouse model was used to investigate the function of miR-1301 overexpression in vivo. Finally, dual luciferase reporter assay was used to verify the binding site of EZH2 and miR-1301. We found that EZH2 induced the expression of miR-1301 in two TNBC cell lines, HCC1937 and HCC1806. Overexpression of miR-1301 suppressed TNBC cell proliferation, migration and colony formation, as well as the xenograft tumor growth in immunodeficient mice. Interestingly, miR-1301 inhibited the expression of EZH2 by binding to the 3'-UTR of EZH2 gene. These data suggest that EZH2 induces the expression of miR-1301 as a negative feedback control mechanism in TNBC.

Prognostic microRNAs and their potential molecular mechanism in pancreatic cancer: A study based on The Cancer Genome Atlas and bioinformatics investigation

Although certain biomarkers that are directly associated with the overall survival (OS) of patients with pancreatic adenocarcinoma (PAAD) have been identified, the efficacy of a single factor is limited to predicting the prognosis. The aim of the present study was to identify a combination micro (mi)RNA signature that enhanced the prognostic prediction for PAAD. Following analysis of the data available from The Cancer Genome Atlas (TCGA), 175 PAAD samples were selected for the present study, and the associations between 494 miRNAs and OS were investigated. The prognostic value of all miRNAs was analyzed by multivariate Cox regression, and the miRNAs were ranked according to the hazard ratio (HR) and P-values. The top 5 miRNAs (miR-1301, miR-125a, miR-376c, miR-328 and miR-376b) were significantly associated with OS (HR=0.139; 95% confidence interval, 0.043–0.443; P<0.001), thus demonstrating that this panel was able to serve as an independent prognostic factor for PAAD. In addition, the present study also predicted the target genes of the top 10 miRNAs with the highest prognostic values using 12 different prediction software, and enrichment signaling pathway analyses elucidated that several pathways may be markedly associated with these miRNAs, including ‘Pathways in cancer’, ‘Chronic myeloid leukemia’, ‘Glioma’ and ‘MicroRNAs in cancer’. Lastly, ubiquitin C, epidermal growth factor receptor, estrogen receptor 1, mitogen-activated protein kinase 1, mothers against decapentaplegic homolog 4 and androgen receptor may be the hub genes revealed by STRING analysis. The present study identified several miRNAs, particularly a five-miRNA-pool, that may be reliable, independent factors for predicting survival in patients with PAAD. However, the underlying molecular mechanisms require further investigation in the future.

Tumor suppressive protein phosphatases in human cancer: Emerging targets for therapeutic intervention and tumor stratification

Aberrant protein phosphorylation is one of the hallmarks of cancer cells, and in many cases a prerequisite to sustain tumor development and progression. Like protein kinases, protein phosphatases are key regulators of cell signaling. However, their contribution to aberrant signaling in cancer cells is overall less well appreciated, and therefore, their clinical potential remains largely unexploited. In this review, we provide an overview of tumor suppressive protein phosphatases in human cancer. Along their mechanisms of inactivation in defined cancer contexts, we give an overview of their functional roles in diverse signaling pathways that contribute to their tumor suppressive abilities. Finally, we discuss their emerging roles as predictive or prognostic markers, their potential as synthetic lethality targets, and the current feasibility of their reactivation with pharmacologic compounds as promising new cancer therapies. We conclude that their inclusion in clinical practice has obvious potential to significantly improve therapeutic outcome in various ways, and should now definitely be pushed forward.

Interaction between miR-572 and PPP2R2C, and their effects on the proliferation, migration, and invasion of nasopharyngeal carcinoma (NPC) cells

We investigated the how miR-572 regulates PPP2R2C, and studied the effects of miR-572 and PPP2R2C on proliferation and migration as well as invasion of nasopharyngeal carcinoma (NPC) cells. NPC tissues and normal tissues were collected, and the expressions of miR-572 and PPP2R2C were detected by real-time PCR. Western blot was applied to detect the expression of PPP2R2C protein. The target relationship between miR-572 and PPP2R2C was confirmed by dual luciferase reporter gene assay. MTT assay and flow cytometry were applied to investigate the viability and apoptosis levels of NPC cells. Transwell as well as wound healing assays were used, respectively, to detect the invasiveness and migration of NPC cells. MiR-572 was highly expressed in NPC tissues as well as NPC cells, and there was lower expression of PPP2R2C in NPC tissues compared with normal samples. MiR-572 could bind to the 3' UTR of PPP2R2C and decrease its expression. Over-expressed miR-572 and decreased PPP2R2C expression could both inhibit proliferation and invasion and induce apoptosis of NPC cells. Thus, miR-572 promotes the proliferation and invasion of NPC by directly down-regulating PPP2R2C.

miR-1301 inhibits hepatocellular carcinoma cell migration, invasion, and angiogenesis by decreasing Wnt/β-catenin signaling through targeting BCL9

Metastasis is the major cause of the poor prognosis of hepatocellular carcinoma (HCC), and increasing evidence supports the contribution of miRNAs to cancer progression. However, the exact relationship between the level of miR-1301 expression and HCC cell migration, invasion, and angiogenesis remains largely unknown. Quantitative PCR was used to evaluate the level of miR-1301 expression in HCC tissues and cell lines. Transwell and tube-formation assays were used to measure the effects of miR-1301 on HCC cell migration and invasion, and angiogenesis, respectively. Luciferase reporter assays and western blotting were used to confirm the miR-1301 target genes. We found that miR-1301 was significantly downregulated in HCC tissues and cell lines. Low miR-1301 expression was associated with tumor vascular invasion and Edmondson grade. Gain- and loss-of-function assays demonstrated that miR-1301 inhibited the migration, invasion, epithelial-mesenchymal transition, and angiogenesis of HCC cells in vitro and in vivo. BCL9, upregulated in HCC tissues compared with matched adjacent normal tissues, was inversely correlated to miR-1301 levels in HCC tissues. Through reporter gene and western blot assays, BCL9 was shown to be a direct miR-1301 target. BCL9 overexpression could partially reverse the effects of miR-1301 on HCC cell migration and invasion. Most importantly, miR-1301 overexpression markedly suppressed the death of xenograft mouse models of cancer by reducing tumor load, metastasis, and host angiogenesis by downregulating BCL9, β-catenin, and vascular endothelial growth factor expression in tumor cells. Our observations suggested that miR-1301 inhibits HCC migration, invasion, and angiogenesis via decreasing Wnt/β-catenin signaling through targeting BCL9, and might be a therapeutic target for HCC.

PTEN loss and p27 loss differ among morphologic patterns of prostate cancer, including cribriform

The presence and extent of cribriform pattern of prostate cancer portend recurrence and cancer death. The relative expressions within this morphology of the prognostically adverse loss of PTEN, and the downstream inactivation of cell cycle inhibitor p27/Kip1 had been uncertain. In this study, we examined 52 cases of cribriform cancer by immunohistochemistry for PTEN, p27, and CD44 variant (v)7/8, and a subset of 17 cases by chromogenic in situ hybridization (ISH) using probes for PTEN or CDKN1B (gene for p27). The fractions of epithelial pixels positive by immunohistochemistry and ISH were digitally assessed for benign acini, high-grade prostatic intraepithelial neoplasia, and 8 morphologic patterns of cancer. Immunostaining results demonstrated that (1) PTEN loss was significant for fused small acini, cribriform-central cells, small cribriform acini, and Gleason grade 5 cells in comparison with other acini; (2) p27 loss was significant only for cribriform-peripheral cells and borderline significant for fused small acini in comparison with benign acini; and (3) CD44v7/8 showed expression loss in cribriform-peripheral cells; other comparisons were not significant. ISH showed that cribriform cancer had significant PTEN loss normalized to benign acini (P<.02), whereas Gleason 3 cancer or fused small acini did not. With CDKN1B, the degree of signal loss among various cancer morphologies was insignificant. In conclusion, molecular disparities emerged between the fused small acini and cribriform patterns of Gleason 4 cancer. PTEN or p27 loss as prognostic factors demands distinct assessment in the varieties of Gleason 4 cancer, and in the biphenotypic peripheral versus central populations in cribriform structures.

Integrated molecular analysis reveals complex interactions between genomic and epigenomic alterations in esophageal adenocarcinomas

The incidence of esophageal adenocarcinoma (EAC) is rapidly rising in the United States and Western countries. In this study, we carried out an integrative molecular analysis to identify interactions between genomic and epigenomic alterations in regulating gene expression networks in EAC. We detected significant alterations in DNA copy numbers (CN), gene expression levels, and DNA methylation profiles. The integrative analysis demonstrated that altered expression of 1,755 genes was associated with changes in CN or methylation. We found that expression alterations in 84 genes were associated with changes in both CN and methylation. These data suggest a strong interaction between genetic and epigenetic events to modulate gene expression in EAC. Of note, bioinformatics analysis detected a prominent K-RAS signature and predicted activation of several important transcription factor networks, including β-catenin, MYB, TWIST1, SOX7, GATA3 and GATA6. Notably, we detected hypomethylation and overexpression of several pro-inflammatory genes such as COX2, IL8 and IL23R, suggesting an important role of epigenetic regulation of these genes in the inflammatory cascade associated with EAC. In summary, this integrative analysis demonstrates a complex interaction between genetic and epigenetic mechanisms providing several novel insights for our understanding of molecular events in EAC.