HIPK1 drives p53 activation to limit colorectal cancer cell growth

HIPK1 Inhibition Protects against Pathological Cardiac Hypertrophy by Inhibiting the CREB-C/EBPβ Axis

Inhibition of pathological cardiac hypertrophy is recognized as an important therapeutic strategy for heart failure, although effective targets are still lacking in clinical practice. Homeodomain interacting protein kinase 1 (HIPK1) is a conserved serine/threonine kinase that can respond to different stress signals, however, whether and how HIPK1 regulates myocardial function is not reported. Here, it is observed that HIPK1 is increased during pathological cardiac hypertrophy. Both genetic ablation and gene therapy targeting HIPK1 are protective against pathological hypertrophy and heart failure in vivo. Hypertrophic stress-induced HIPK1 is present in the nucleus of cardiomyocytes, while HIPK1 inhibition prevents phenylephrine-induced cardiomyocyte hypertrophy through inhibiting cAMP-response element binding protein (CREB) phosphorylation at Ser271 and inactivating CCAAT/enhancer-binding protein β (C/EBPβ)-mediated transcription of pathological response genes. Inhibition of HIPK1 and CREB forms a synergistic pathway in preventing pathological cardiac hypertrophy. In conclusion, HIPK1 inhibition may serve as a promising novel therapeutic strategy to attenuate pathological cardiac hypertrophy and heart failure.

Downregulation of circ-ZNF644 alleviates LPS-induced HK2 cell injury via miR-335-5p/HIPK1 axis

Circular RNA (circRNA) has been confirmed to be involved in regulating sepsis-induced acute kidney injury (AKI). Our research aims to explore circ-ZNF644 role in the development of sepsis-induced AKI. Lipopolysaccharide (LPS) was used to induce kidney tubular epithelial cell (HK2) injury. ELISA assay was performed to measure the concentrations of inflammation factors. Cell functions were determined by cell counting kit 8 assay, EdU assay and flow cytometry. Protein expression was evaluated by Western blot analysis. Quantitative real-time PCR was used to detect relative expression of circ-ZNF644, miR-335-5p and homeodomain-interacting protein kinase 1 (HIPK1). RNA interaction was confirmed by dual-luciferase reporter assay and RIP assay. LPS enhanced HK2 cell inflammation, oxidative stress, apoptosis, and reduced proliferation. Circ-ZNF644 was overexpressed in sepsis-induced AKI patients. Circ-ZNF644 knockdown suppressed LPS-induced HK2 cell injury, and this effect could be revoked by miR-335-5p inhibitor. MiR-335-5p was sponged by circ-ZNF644, and its expression was downregulated in sepsis-induced AKI patients. HIPK1 was targeted by miR-335-5p, and its expression could be suppressed by circ-ZNF644 knockdown. MiR-335-5p had an inhibition effect on HK2 cell injury induced by LPS, and HIPK1 overexpression could reverse this effect. Circ-ZNF644 knockdown relieved LPS-induced HK2 cell injury through the miR-335-5p/HIPK1 axis, confirming that circ-ZNF644 contributed to sepsis-induced AKI.

miR‑146b‑5p activation of hepatic stellate cells contributes to the progression of fibrosis by directly targeting HIPK1

The present study aimed to explore the biological functions of microRNA (miR)-146b-5p and homeodomain interacting protein kinase 1 (HIPK1) in the progression of hepatic fibrosis (HF) and to identify the underlying mechanism. A rat HF model was established by administering a subcutaneous injection of carbon tetrachloride (CCl₄). Relative levels of miR-146b-5p and HIPK1 in fibrotic rat liver tissues and the rat hepatic stellate cell (HSC) line HSC-T6 were measured by quantitative reverse transcription PCR, western blotting and immunohistochemistry. Following activation of HSC-T6 cells by lipopolysaccharide (LPS) induction, cell viability was examined by MTT assay. Transfection of miR-146b-5p mimic or inhibitor into HSC-T6 cells was performed, with the aim to identify the influence of miR-146b-5p on HSC-T6 cell behavior. The targeting relationship between miR-146b-5p and HIPK1 was predicted by TargetScan 7.2 and StarBase 3.0 and it was later verified by a dual-luciferase reporter assay. Through lentivirus transfection, the biological function of HIPK1 in regulating the progression of HF and the underlying mechanism were investigated. The results showed that miR-146b-5p was upregulated in liver tissues of rats with HF and activated HSC-T6 cells, while HIPK1 was downregulated in liver tissues of rats with HF and activated HSC-T6 cells. miR-146b-5p was able to upregulate the activation markers of LPS-induced HSC-T6 cells, upregulate COL1A1 and TGF-β, increase cell viability and contribute to fibrosis progression. HIPK1 was validated as the direct target of miR-146b-5p and its overexpression could effectively reduce the effect of miR-146b-5p in contribution to the progression of HF. In conclusion, miR-146b-5p was significantly upregulated during the progression of HF. By targeting and downregulating HIPK1, miR-146b-5p could significantly activate HSCs, upregulate COL1A1 and TGF-β and contribute to fibrosis progression. miR-146b-5p is a potential biomarker and therapeutic target for HF.

Deciphering the Role of 3D Genome Organization in Breast Cancer Susceptibility

Cancer risk by environmental exposure is modulated by an individual's genetics and age at exposure. This age-specific period of susceptibility is referred to as the "Window of Susceptibility" (WOS). Rats have a similar WOS for developing breast cancer. A previous study in rat identified an age-specific long-range regulatory interaction for the cancer gene, Pappa, that is associated with breast cancer susceptibility. However, the global role of three-dimensional genome organization and downstream gene expression programs in the WOS is not known. Therefore, we generated Hi-C and RNA-seq data in rat mammary epithelial cells within and outside the WOS. To systematically identify higher-order changes in 3D genome organization, we developed NE-MVNMF that combines network enhancement followed by multitask non-negative matrix factorization. We examined three-dimensional genome organization dynamics at the level of individual loops as well as higher-order domains. Differential chromatin interactions tend to be associated with differentially up-regulated genes with the WOS and recapitulate several human SNP-gene interactions associated with breast cancer susceptibility. Our approach identified genomic blocks of regions with greater overall differences in contact count between the two time points when the cluster assignments change and identified genes and pathways implicated in early carcinogenesis and cancer treatment. Our results suggest that WOS-specific changes in 3D genome organization are linked to transcriptional changes that may influence susceptibility to breast cancer.

MicroRNA-889-3p restrains the proliferation and epithelial-mesenchymal transformation of lung cancer cells via down-regulation of Homeodomain-interacting protein kinase 1

Dysregulated microRNAs (miRNAs) are common in human cancers and are involved in the proliferation, promotion, and metastasis of tumor cells. Therefore, the aim of this study was to evaluate the expression and biological function of miR-889-3p in lung cancer (LC). MiR-889-3p and Homeodomain-interacting protein kinase 1 (HIPK1) expression was detected in human LC tissues and cells. The correlation of miR-889-3p with the clinicopathology of LC patients was observed. After the transfection of miR-889-3p and HIPK1-related plasmids in human LC cell line A549, several studies were employed for detection of cell growth. In addition, the targeting of miR-889-3p with HIPK1 was verified. The results clarified miR-889-3p was down-regulated, while HIPK1 was up-regulated in LC tissues. Elevated miR-889-3p or repressed HIPK1 weakened the viability, epithelial–mesenchymal transition (EMT), invasion, migration of LC cells, whereas strengthened apoptosis. MiR-889-3p targeted HIPK1; MiR-889-3p mediated HIPK1 to affect the proliferation and EMT of LC cells. Therefore, it is concluded that miR-889-3p repressing HIPK1 restrains the proliferation and EMT of LC cells, providing a novel target for LC therapy.

RNAi therapeutic strategies for acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS), replacing the clinical term acute lung injury, involves serious pathophysiological lung changes that arise from a variety of pulmonary and nonpulmonary injuries and currently has no pharmacological therapeutics. RNA interference (RNAi) has the potential to generate therapeutic effects that would increase patient survival rates from this condition. It is the purpose of this review to discuss potential targets in treating ARDS with RNAi strategies, as well as to outline the challenges of oligonucleotide delivery to the lung and tactics to circumvent these delivery barriers.

miR-770-5p modulates resistance to methotrexate in human colorectal adenocarcinoma cells by downregulating HIPK1

Colon cancer is one of the most common types of cancer worldwide. Methotrexate (MTX) is a chemotherapy drug used for the treatment of multiple types of cancer, such as colon and breast cancer. To determine the effects of MTX treatment on colorectal adenocarcinoma cell lines, a microRNA (miRNA) microarray was used to detect miRNA expression profiles of HT-29 colorectal adenocarcinoma MTX-resistant cells and their parental cells. The results demonstrated that 641 genes and 43 miRNAs were differentially expressed between HT-29 MTX-sensitive cells and MTX-resistant cells. In addition, 12 miRNAs and their co-expressed genes were highly correlated in MTX treatment, and one of the identified miRNAs, miR-770-5p, was studied in subsequent experiments. Upregulation of miR-770-5p significantly decreased the sensitivity of HT-29 cells to MTX. Using bioinformatics software, homeodomain-interacting protein kinase 1 (HIPK1) was identified to be a putative target gene of miR-770-5p, which was confirmed by a luciferase reporter assay. Downregulation of miR-770-5p target gene HIPK1 significantly decreased the sensitivity of HT-29 cells to MTX. These results suggest that miR-770-5p may be involved in the regulation of colon cancer resistance to MTX by regulating the expression of the target gene HIPK1.

A positive feedback loop between Myc and aerobic glycolysis sustains tumor growth in a Drosophila tumor model

Cancer cells usually exhibit aberrant cell signaling and metabolic reprogramming. However, mechanisms of crosstalk between these processes remain elusive. Here, we show that in an in vivo tumor model expressing oncogenic Drosophila Homeodomain-interacting protein kinase (Hipk), tumor cells display elevated aerobic glycolysis. Mechanistically, elevated Hipk drives transcriptional upregulation of Drosophila Myc (dMyc; MYC in vertebrates) likely through convergence of multiple perturbed signaling cascades. dMyc induces robust expression of pfk2 (encoding 6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase; PFKFB in vertebrates) among other glycolytic genes. Pfk2 catalyzes the synthesis of fructose-2,6-bisphosphate, which acts as a potent allosteric activator of Phosphofructokinase (Pfk) and thus stimulates glycolysis. Pfk2 and Pfk in turn are required to sustain dMyc protein accumulation post-transcriptionally, establishing a positive feedback loop. Disruption of the loop abrogates tumorous growth. Together, our study demonstrates a reciprocal stimulation of Myc and aerobic glycolysis and identifies the Pfk2-Pfk governed committed step of glycolysis as a metabolic vulnerability during tumorigenesis.

Cancer arises when cells in the body divide and grow excessively. These cells will often also take up more glucose than normal cells and break it down into another chemical known as lactate faster. This change to the chemical reactions happening within the cell, also called a metabolic change, is required to help produce the extra DNA, proteins and fatty molecules that it needs to grow.

Elevated levels of certain proteins can trigger the changes that lead to the growth of tumors. MYC (called dMyc in fruit flies) is one of these proteins. It controls cell division and increases the production of enzymes that break down glucose. Hipk is another protein that can induce tumor growth in fruit flies, but how it does so was unknown.

Here, Wong et al. show that high levels of Hipk boost glucose metabolism and accumulation of dMyc protein in fruit fly cells. They also describe the link between increased glucose metabolism and uncontrolled cell division.

First, fruit fly cells were fed a fluorescent molecule similar to glucose that cannot be broken down by the cells. This experiment established that glucose uptake increases in cells with too much Hipk. These cells also break down glucose faster, confirming that they have increased glucose metabolism.

Cells with high levels of Hipk also activate the genes that generate the enzymes involved in glucose breakdown, and increase the activity of the gene coding for dMyc. Levels of the dMyc protein are higher in these cells, which was shown by staining the cells with fluorescent molecules that specifically bind the dMyc protein. It is this buildup of dMyc protein that activates the genes coding for the enzymes responsible for glucose breakdown. PFK2 is one of these enzymes.

Finally, Wong et al. inhibited the production of the enzymes that are elevated in cells with high Hipk. Stopping the production of PFK2 prevents both tumor growth and the accumulation of dMyc protein. This shows that high levels of dMyc increase PFK2 levels, leading to further dMyc buildup, and creating a loop that links the uncontrolled cell division caused by too much dMyc and the shift to higher glucose metabolism.

These results highlight new potential targets for cancer therapy, showing that targeting glucose metabolism may reduce, or even stop, tumor growth.

Differential intracellular localization and dynamic nucleocytoplasmic shuttling of homeodomain-interacting protein kinase family members

The three canonical members of the family of homeodomain-interacting protein (HIP) kinases fulfill overlapping and distinct roles in cellular stress response pathways. Here we systematically compared all three endogenous HIPKs for their intracellular distribution and mutual interactions. The endogenous HIPKs are contained in high molecular weight complexes of ~700 kDa but do not directly interact physically. Under basal conditions, HIPK1 was mostly cytoplasmic, while HIPK3 was found in the nucleus and HIPK2 occurred in both compartments. Inhibition of nuclear export by leptomycin B resulted in the nuclear accumulation of mainly HIPK1 and HIPK2, indicating constitutive dynamic nucleocytoplasmic shuttling. The carcinogenic chemical stressor sodium arsenite caused the induction of HIPK2-dependent cell death and also resulted in a rapid and complete nuclear translocation of HIPK2, showing that the intracellular distribution of this kinase can undergo dynamic regulation.

Comprehensive analysis of microarray expression profiles of circRNAs and lncRNAs with associated co-expression networks in human colorectal cancer

Increasing data demonstrate that circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs) play important roles in tumorigenesis. However, the mechanisms in colorectal cancer (CRC) remain unclear. Here, hundreds of significantly expressed circRNAs, and thousands of lncRNAs as well as mRNAs were identified. By qRT-PCR, one abnormal circRNA, lncRNA, and three mRNAs were verified in 24 pairs of tissues and blood samples, respectively. Then, by GO analysis, we found that the gene expression profile of linear counterparts of upregulated circRNAs in human CRC tissues preferred positive regulation of GTPase activity, cellular protein metabolic process, and protein binding, while that of downregulated circRNAs of CRC preferred positive regulation of cellular metabolic process, acetyl-CoA metabolic process, and protein kinase C activity. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that p53 signaling pathway was an important pathway in upregulated protein-coding genes, whereas cyclic guanosine monophosphate-protein kinase G (cGMP-PKG) signaling pathway was the top enriched KEGG pathway for downregulated transcripts. Furthermore, lncRNA-mRNA co-expression analysis demonstrated that downregulated lncRNA uc001tma.3 was negatively with CDC45 and positively with ELOVL4, BVES, FLNA, and HSPB8, while upregulated lncRNA NR_110882 was positively with FZD2. In addition, lncRNA-transcription factor (TF) co-expression analysis showed that the most relevant TFs were forkhead box protein A1 (FOXA1), transcription initiation factor TFIID submint 7 (TAF7), and adenovirus early region 1A(E1A)-associated protein p300 (EP300). Our findings offer a fresh view on circRNAs and lncRNAs and provide the foundation for further study on the potential roles of circRNAs and lncRNAs in colorectal cancer.

HIPK1 Interference Attenuates Inflammation and Oxidative Stress of Acute Lung Injury via Autophagy

<strong>BACKGROUND</strong> Acute respiratory distress syndrome (ARDS), which is characterized by severe hypoxemia (PaO2/FIO2 ≤300 mmHg), is usually companied by uncontrolled inflammation, oxidative injury, and the damage to the alveolar-capillary barrier. Severe ARDS is usually companied with acute lung injury that worsen the patients' condition. HIPK1 is a modulator of homeodomain-containing transcription factors and regulates multiple cellular biological process associated with inflammation and anti-stress responses. <strong>MATERIAL AND METHODS</strong> We used an LPS-induced mouse acute lung injury (ALI) model to investigate the possible role of HIPK1 in ALI pathophysiology. <strong>RESULTS</strong> We found the HIPK1 was elevated in ALI model mice while interference of HIPK1 by siRNA attenuated the inflammation and oxidative stress indicators (H2O2, O-2, and NO). Further research found HIPK1 interference enhanced the autophagy. <strong>CONCLUSIONS</strong> Decreased HIPK1 in ALI showed protective effects in attenuating inflammation and oxidative stress and enhancing autophagy, indicating HIPK1 as a possible target in ALI management.

miR-200c/141 Regulates Breast Cancer Stem Cell Heterogeneity via Targeting HIPK1/β-Catenin Axis

Increasing evidence demonstrates the existence of two inter-convertible states of breast cancer stem cells (BCSCs) with distinct behaviors in proliferation and mobility, and the BCSC heterogeneity is accurately regulated by sophisticated mechanisms including microRNAs. The microRNA-200 family including miR-200c/141 cluster was reported to affect cancer cell invasion and metastasis by regulating epithelial to mesenchymal transition (EMT). However, the effect of miR-200 family on BCSC heterogeneity is uncertain. Thus, we investigated whether the miR-200c/141 cluster had different effects on breast tumor growth and metastasis by switching the two states of BCSC.

Methods: The spontaneous mammary tumor mouse model with miR-200c/141 conditional knockout was utilized for analyzing the role of miR-200c/141 cluster in vivo. The effect of miR-200c/141 cluster on BCSCs was performed by CD24/CD29 staining and ALDEFLUOR assay. miR-200c/141 target expression and EMT-related marker expression were verified in tumor sections, primary cells and breast cancer cell lines by qRT-PCR or western blotting. Statistical analysis was determined using two-way ANOVA and Student's t-test. All values were presented as the mean ± s.e.m.

Results: The deletion of miR-200c/141 cluster regulated BCSC heterogeneity and promoted the EMT-like BCSC generation, which resulted in increased tumor metastasis and inhibited tumor growth by directly upregulating the target gene homeodomain-interacting protein kinase 1 (HIPK1) and sequential β-catenin activation.

Conclusions: Our results indicated that miR-200c/141 played biphasic roles in breast tumor progression via affecting the BCSC heterogeneity, suggesting targeting BCSC heterogeneity to simultaneously restrict breast cancer initiation and metastasis could be a promising therapeutic strategy for breast cancer.

The expression level and prognostic value of HIPK3 among non-small-cell lung cancer patients in China

Background

Lung cancer is one of the most common malignancies in the world and is at the forefront of causes of all cancer deaths. Identification of new prognostic predictors or therapeutic targets might improve a patient's survival rate.

Purpose

The Homeodomain interacting protein kinases (HIPKs) function as modulators of cellular stress responses and regulate cell differentiation, proliferation and apoptosis, but the function of HIPK3 is remain unknown.

Patients and methods

We used quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting methods to detective the expression of HIPK3. A total of 206 samples were obtained from patients and Immunochemical evaluation to determine HIPK3 protein expression. HIPK3 protein levels in in non-small cell lung cancer (NSCLC) were correlated with the clinical characteristics of patients and their 5-year survival rate. In addition, HIPK3 knockdown by specific RNAi promoted cell proliferation, migration, and invasion in A549 and HCC827 cancer cell lines.

Results

The quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting methods to demonstrate that HIPK3 expression was significantly down-regulated in non-small cell lung cancer (NSCLC) tissues compared with that in normal lung tissues. At the same time, the results of immunohistochemistry assays showed that low expression of HIPK3 was significantly associated with pathology grade; tumor, node, and metastases (TNM) stage; lymph node metastasis; Ki-67 expression; and the 5-year survival rate in NSCLC patients. Univariate analysis revealed that HIPK3 expression, Ki-67 expression, tumor diameter, TNM stage, and age were significantly associated with a poor prognosis. The multivariable analysis illustrated that HIPK3, tumor diameter, TNM, Ki-67 expression, and age had effects on the overall survival of NSCLC patients independently. Kaplan-Meier survival curves revealed that NSCLC patients with a lower HIPK3 expression had a poorer prognosis. In addition, in vivo results also confirmed that HIPK3 over-expression could inhibit tumor growth.

Conclusion

Our findings confirmed that low expression of HIPK3 in NSCLC tissues was significantly correlated with poor survival rates after curative resection. HIPK3 could potentially be used as a valuable biomarker in the prognosis of the survival of NSCLC patients.

Sipi soup inhibits cancer‑associated fibroblast activation and the inflammatory process by downregulating long non‑coding RNA HIPK1‑AS

Sipi soup (SPS), the aqueous extract derived from the root bark of Sophora japonical L, Salix babylonica L., Morus alba L., as well as Amygdalus davidiana (Carr.) C. de Vos, is a traditional Chinese medicine frequently used to prevent and treat infection and inflammation. However, the role of SPS in cancer-associated fibroblasts (CAFs) require further investigation. In the present study, the effects of SPS on fibroblast inactivation and the underlying mechanism were investigated. Reverse transcription-quantitative polymerase chain reaction was used to analyze the mRNA expression levels of fibroblast activation protein (FAP), interleukin (IL)-6, α-smooth muscle actin (α-SMA) and programmed cell death 4 (PDCD4). Flow cytometry was used to evaluate cell apoptosis. Immunofluorescence was used to determine the number of activated fibroblasts. The present study reported that SPS treatment did not affect the proliferative apoptotic potential of fibroblasts. Treatment with HeLa cell culture medium (CM) induced a significant increase in the expression levels of FAP, IL-6 and α-SMA, but reduced the expression of PDCD4. SPS reversed the effects of HeLa CM on the expression of these genes. Analysis with a long non-coding (lnc)RNA array of numerous differentially expressed lncRNAs revealed that the expression levels of the lncRNA homeodomain-interacting protein kinase 1 antisense RNA (HIPK1-AS) were increased in cervicitis tissues and cervical squamous cell carcinoma tissues compared with in normal cervical tissues. HIPK1-AS expression levels were upregulated in response to HeLa CM, but were decreased under SPS treatment. The downregulation of HIPK1-AS expression via short hairpin RNA abolished the effects of HeLa CM on the expression of inflammation-associated genes. The findings of the present study suggested that SPS may prevent the progression of cervical cancer by inhibiting the activation of CAF and the inflammatory process by reducing HIPK1-AS expression.

miR-204-5p and miR-3065-5p exert antitumor effects on melanoma cells

MicroRNA (miR)-204-5p was previously identified to be downregulated in melanoma compared with melanocytic nevi. This observation prompted a functional study on miR-204-5p and the newly-identified miR-3065-5p, two miRNAs suggested to be tumor-suppressive oncomiRs. Application of miR-204-5p mimics or inhibitors resulted in a decrease or increase, respectively, in melanoma cell proliferation and colony formation. miR-204-5p mimics hindered invasion, whereas miR-204-5p inhibitors stimulated cancer cell migration. Modulation of miR-3065-5p led to a decrease in melanoma cell proliferation, altered cell cycle distribution and increased expression levels of its target genes HIPK1 and ITGA1, possibly due to functional modifications identified in these cells. miR-204-5p and miR-3065-5p demonstrated antitumor capacities that may need to be taken into account in the development of melanoma treatment approaches.

Homeodomain-interacting protein kinase promotes tumorigenesis and metastatic cell behavior

Aberrations in signaling pathways that regulate tissue growth often lead to tumorigenesis. Homeodomain-interacting protein kinase (Hipk) family members are reported to have distinct and contradictory effects on cell proliferation and tissue growth. From these studies, it is clear that much remains to be learned about the roles of Hipk family protein kinases in proliferation and cell behavior. Previous work has shown that Drosophila Hipk is a potent growth regulator, thus we predicted that it could have a role in tumorigenesis. In our study of Hipk-induced phenotypes, we observed the formation of tumor-like structures in multiple cell types in larvae and adults. Furthermore, elevated Hipk in epithelial cells induces cell spreading, invasion and epithelial-to-mesenchymal transition (EMT) in the imaginal disc. Further evidence comes from cell culture studies, in which we expressed Drosophila Hipk in human breast cancer cells and showed that it enhances proliferation and migration. Past studies have shown that Hipk can promote the action of conserved pathways implicated in cancer and EMT, such as Wnt/Wingless, Hippo, Notch and JNK. We show that Hipk phenotypes are not likely to arise from activation of a single target, but rather through a cumulative effect on numerous target pathways. Most Drosophila tumor models involve mutations in multiple genes, such as the well-known Ras^V12 model, in which EMT and invasiveness occur after the additional loss of the tumor suppressor gene scribble. Our study reveals that elevated levels of Hipk on their own can promote both hyperproliferation and invasive cell behavior, suggesting that Hipk family members could be potent oncogenes and drivers of EMT.

Summary: The protein kinase Hipk can promote proliferation and invasive behaviors, and can synergize with known cancer pathways, in a new Drosophila model for tumorigenesis.

Unveiling MYCN regulatory networks in neuroblastoma via integrative analysis of heterogeneous genomics data

MYCN, an oncogenic transcription factor of the Myc family, is a major driver of neuroblastoma tumorigenesis. Due to the difficulty in drugging MYCN directly, revealing the molecules in MYCN regulatory networks will help to identify effective therapeutic targets for neuroblastoma therapy. Here we perform ChIP-sequencing and small RNA-sequencing of neuroblastoma cells to determine the MYCN-binding sites and MYCN-associated microRNAs, and integrate various types of genomic data to construct MYCN regulatory networks. The overall analysis indicated that MYCN-regulated genes were involved in a wide range of biological processes and could be used as signatures to identify poor-prognosis MYCN-non-amplified patients. Analysis of the MYCN binding sites showed that MYCN principally served as an activator. Using a computational approach, we identified 32 MYCN co-regulators, and some of these findings are supported by previous studies. Moreover, we investigated the interplay between MYCN transcriptional and microRNA post-transcriptional regulations and identified several microRNAs, such as miR-124-3p and miR-93-5p, which may significantly contribute to neuroblastoma pathogenesis. We also found MYCN and its regulated microRNAs acted together to repress the tumor suppressor genes. This work provides a comprehensive view of MYCN regulations for exploring therapeutic targets in neuroblastoma, as well as insights into the mechanism of neuroblastoma tumorigenesis.

Identifying HIPK1 as Target of miR-22-3p Enhancing Recombinant Protein Production From HEK 293 Cell by Using Microarray and HTP siRNA Screen

Protein expression from human embryonic kidney cells (HEK 293) is an important tool for structural and clinical studies. It is previously shown that microRNAs (small, noncoding RNAs) are effective means for improved protein expression from these cells, and by conducting a high-throughput screening of the human microRNA library, several microRNAs are identified as potential candidates for improving expression. From these, miR-22-3p is chosen for further study since it increased the expression of luciferase, two membrane proteins and a secreted fusion protein with minimal effect on the cells' growth and viability. Since each microRNA can interact with several gene targets, it is of interest to identify the repressed genes for understanding and exploring the improved expression mechanism for further implementation. Here, the authors describe a novel approach for identification of the target genes by integrating the differential gene expression analysis with information obtained from our previously conducted high-throughput siRNA screening. The identified genes were validated as being involved in improving luciferase expression by using siRNA and qRT-PCR. Repressing the target gene, HIPK1, is found to increase luciferase and GPC3 expression 3.3- and 2.2-fold, respectively.

Quantitative Phosphoproteomic Analysis Reveals Key Mechanisms of Cellular Proliferation in Liver Cancer Cells

Understanding the mechanisms of uncontrolled proliferation in cancer cells provides valuable insights into tumor development and is benefit for discovering efficient methods in cancer treatment. In this study, we identified and quantified 2,057 phosphoproteins and 9,824 unique phosphosites in three liver cell lines with high (QGY, Hep3B) and low (L02) proliferative potentials and disclosed the wide variations in phosphorylation sites and levels among them. We found that the number of identified phosphoproteins and phosphosites in these cells were negatively correlated with their proliferative abilities. The function analysis suggested that the aberrant phosphorylation of SR proteins and activation of MAPK pathway might be two critical factors to promote cancer cell proliferation. Meanwhile, the phosphorylation status of mini-chromosome maintenance (MCM) and nuclear pore (NPC) complexes are significantly different between cell lines with high and low proliferative potentials. Furthermore, the phosphosites targeted by kinase families of CDK, STE and HIPK in the proteins coded by cancer driver genes showed distinct profiles between caner and normal cell lines. These results present key phosphorylation networks involving in abnormal proliferation of cancer cells and uncovered potential molecular markers for estimating the proliferation ability of liver cancer cells.

Homeodomain-Interacting Protein Kinases: Diverse and Complex Roles in Development and Disease

The Homeodomain-interacting protein kinase (Hipk) family of proteins plays diverse, and at times conflicting, biological roles in normal development and disease. In this review we will highlight developmental and cellular roles for Hipk proteins, with an emphasis on the pleiotropic and essential physiological roles revealed through genetic studies. We discuss the myriad ways of regulating Hipk protein function, and how these may contribute to the diverse cellular roles. Furthermore we will describe the context-specific activities of Hipk family members in diseases such as cancer and fibrosis, including seemingly contradictory tumor-suppressive and oncogenic activities. Given the diverse signaling pathways regulated by Hipk proteins, it is likely that Hipks act to fine-tune signaling and may mediate cross talk in certain contexts. Such regulation is emerging as vital for development and in disease.

Exosomes Secreted by Toxoplasma gondii-Infected L6 Cells: Their Effects on Host Cell Proliferation and Cell Cycle Changes

Toxoplasma gondii infection induces alteration of the host cell cycle and cell proliferation. These changes are not only seen in directly invaded host cells but also in neighboring cells. We tried to identify whether this alteration can be mediated by exosomes secreted by T. gondii-infected host cells. L6 cells, a rat myoblast cell line, and RH strain of T. gondii were selected for this study. L6 cells were infected with or without T. gondii to isolate exosomes. The cellular growth patterns were identified by cell counting with trypan blue under confocal microscopy, and cell cycle changes were investigated by flow cytometry. L6 cells infected with T. gondii showed decreased proliferation compared to uninfected L6 cells and revealed a tendency to stay at S or G2/M cell phase. The treatment of exosomes isolated from T. gondii-infected cells showed attenuation of cell proliferation and slight enhancement of S phase in L6 cells. The cell cycle alteration was not as obvious as reduction of the cell proliferation by the exosome treatment. These changes were transient and disappeared at 48 hr after the exosome treatment. Microarray analysis and web-based tools indicated that various exosomal miRNAs were crucial for the regulation of target genes related to cell proliferation. Collectively, our study demonstrated that the exosomes originating from T. gondii could change the host cell proliferation and alter the host cell cycle.

Peritoneal expression of Matrilysin helps identify early post-operative recurrence of colorectal cancer

Recurrence of colorectal cancer (CRC) following a potentially curative resection is a challenging clinical problem. Matrix metalloproteinase-7 (MMP-7) is over-expressed by CRC cells and supposed to play a major role in CRC cell diffusion and metastasis. MMP-7 RNA expression was assessed by real-time PCR using specific primers in peritoneal washing fluid obtained during surgical procedure. After surgery, patients underwent a regular follow up for assessing recurrence. transcripts for MMP-7 were detected in 31/57 samples (54%). Patients were followed-up (range 20-48 months) for recurrence prevention. Recurrence was diagnosed in 6 out of 55 patients (11%) and two patients eventually died because of this. Notably, all the six patients who had relapsed were positive for MMP-7. Sensitivity and specificity of the test were 100% and 49% respectively. Data from patients have also been corroborated by computational approaches. Public available coloncarcinoma datasets have been employed to confirm MMP7 clinical impact on the disease. Interestingly, MMP-7 expression appeared correlated to Tgfb-1, and correlation of the two factors represented a poor prognostic factor. This study proposes positivity of MMP-7 in peritoneal cavity as a novel biomarker for predicting disease recurrence in patients with CRC.

Clinico-Pathological Association of Delineated miRNAs in Uveal Melanoma with Monosomy 3/Disomy 3 Chromosomal Aberrations

Purpose

To correlate the differentially expressed miRNAs with clinico-pathological features in uveal melanoma (UM) tumors harbouring chromosomal 3 aberrations among South Asian Indian cohort.

Methods

Based on chromosomal 3 aberration, UM (n = 86) were grouped into monosomy 3 (M3; n = 51) and disomy 3 (D3; n = 35) by chromogenic in-situ hybridisation (CISH). The clinico-pathological features were recorded. miRNA profiling was performed in formalin fixed paraffin embedded (FFPE) UM samples (n = 6) using Agilent, Human miRNA microarray, 8x15KV3 arrays. The association between miRNAs and clinico-pathological features were studied using univariate and multivariate analysis. miRNA-gene targets were predicted using Target-scan and MiRanda database. Significantly dys-regulated miRNAs were validated in FFPE UM (n = 86) and mRNAs were validated in frozen UM (n = 10) by qRT-PCR. Metastasis free-survival and miRNA expressions were analysed by Kaplen-Meier analysis in UM tissues (n = 52).

Results

Unsupervised analysis revealed 585 differentially expressed miRNAs while supervised analysis demonstrated 82 miRNAs (FDR; Q = 0.0). Differential expression of 8 miRNAs: miR-214, miR-149*, miR-143, miR-146b, miR-199a, let7b, miR-1238 and miR-134 were studied. Gene target prediction revealed SMAD4, WISP1, HIPK1, HDAC8 and C-KIT as the post-transcriptional regulators of miR-146b, miR-199a, miR-1238 and miR-134. Five miRNAs (miR-214, miR146b, miR-143, miR-199a and miR-134) were found to be differentially expressed in M3/ D3 UM tumors. In UM patients with liver metastasis, miR-149* and miR-134 expressions were strongly correlated.

Conclusion

UM can be stratified using miRNAs from FFPE sections. miRNAs predicting liver metastasis and survival have been identified. Mechanistic linkage of de-regulated miRNA/mRNA expressions provide new insights on their role in UM progression and aggressiveness.

The MAP3K ZAK, a novel modulator of ERK-dependent migration, is upregulated in colorectal cancer

Often described as a mediator of cell cycle arrest or as a pro-apoptotic factor in stressful conditions, the MAP3K ZAK (Sterile alpha motif and leucine zipper-containing kinase) has also been proven to positively regulate epidermal growth factor receptor (EGFR) and WNT signaling pathways, cancer cell proliferation and cellular neoplastic transformation. Here, we show that both isoforms of ZAK, ZAK-α and ZAK-β are key factors in cancer cell migration. While ZAK depletion reduced cell motility of HeLa and HCT116 cells, its overexpression triggered the activation of all three mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase (ERK), c-JUN N-terminal kinase (JNK) and p38, as well as an increase in cell motion. On the contrary, the kinase-dead mutants, ZAK-α K45M and ZAK-β K45M, were not able to provoke such events, and instead exerted a dominant-negative effect on MAPK activation and cell migration. Pharmacological inhibition of ZAK by nilotinib, preventing ZAK-autophosphorylation and thereby auto-activation, led to the same results. Activated by epidermal growth factor (EGF), we further showed that ZAK constitutes an essential element of the EGF/ERK-dependent cell migration pathway. Using public transcriptomic databases and tissue microarrays, we finally established that, as strong factors of the EGFR signaling pathway, ZAK-α and/or ZAK-β transcripts and protein(s) are frequently upregulated in colorectal adenoma and carcinoma patients. Notably, gene set enrichment analysis disclosed a significant correlation between ZAK+ colorectal premalignant lesions and gene sets belonging to the MAPK/ERK and motility-related signaling pathways of the reactome database, strongly suggesting that ZAK induces such pro-tumoral reaction cascades in human cancers.

Integration of stress signals by homeodomain interacting protein kinases

The family of homeodomain interacting protein kinases (HIPKs) consists of four related kinases, HIPK1 to HIPK4. These serine/threonine kinases are evolutionary conserved and derive from the yeast kinase Yak1. The largest group of HIPK phosphorylation substrates is represented by transcription factors and chromatin-associated regulators of gene expression, thus transferring HIPK-derived signals into changes of gene expression programs. The HIPKs mainly function as regulators of developmental processes and as integrators of a wide variety of stress signals. A number of conditions representing precarious situations, such as DNA damage, hypoxia, reactive oxygen intermediates and metabolic stress affect the function of HIPKs. The kinases function as integrators for these stress signals and feed them into many different downstream effector pathways that serve to cope with these precarious situations. HIPKs do not function as essential core components in the different stress signaling pathways, but rather serve as modulators of signal output and as connectors of different stress signaling pathways. Their central role as signaling hubs with the ability to shape many downstream effector pathways frequently implies them in proliferative diseases such as cancer or fibrosis.