Fam64a is a novel cell cycle promoter of hypoxic fetal cardiomyocytes in mice

Transition from fetal to postnatal state in the heart: Crosstalk between metabolism and regeneration

Cardiovascular disease is the leading cause of mortality worldwide. Myocardial injury resulting from ischemia can be fatal because of the limited regenerative capacity of adult myocardium. Mammalian cardiomyocytes rapidly lose their proliferative capacities, with only a small fraction of adult myocardium remaining proliferative, which is insufficient to support post-injury recovery. Recent investigations have revealed that this decline in myocardial proliferative capacity is closely linked to perinatal metabolic shifts. Predominantly glycolytic fetal myocardial metabolism transitions towards mitochondrial fatty acid oxidation postnatally, which not only enables efficient production of ATP but also causes a dramatic reduction in cardiomyocyte proliferative capacity. Extensive research has elucidated the mechanisms behind this metabolic shift, as well as methods to modulate these metabolic pathways. Some of these methods have been successfully applied to enhance metabolic reprogramming and myocardial regeneration. This review discusses recently acquired insights into the interplay between metabolism and myocardial proliferation, emphasizing postnatal metabolic transitions.

Loss of connectin novex-3 leads to heart dysfunction associated with impaired cardiomyocyte proliferation and abnormal nuclear mechanics

Connectin (also known as titin) is a giant striated muscle protein that functions as a molecular spring by providing elasticity to the sarcomere. Novex-3 is a short splice variant of connectin whose physiological function remains unknown. We have recently demonstrated using in vitro analyses that in addition to sarcomere expression, novex-3 was also expressed in cardiomyocyte nuclei exclusively during fetal life, where it provides elasticity/compliance to cardiomyocyte nuclei and promotes cardiomyocyte proliferation in the fetus, suggesting a non-sarcomeric function. Here, we analyzed novex-3 knockout mice to assess the involvement of this function in cardiac pathophysiology in vivo. Deficiency of novex-3 compromised fetal cardiomyocyte proliferation and induced the enlargement of individual cardiomyocytes in neonates. In adults, novex-3 deficiency resulted in chamber dilation and systolic dysfunction, associated with Ca2+ dysregulation, resulting in a reduced life span. Mechanistic analyses revealed a possible association between impaired proliferation and abnormal nuclear mechanics, including stiffer nuclei positioned peripherally with stabilized circumnuclear microtubules in knockout cardiomyocytes. Although the underlying causal relationships were not fully elucidated, these data show that novex-3 has a vital non-sarcomeric function in cardiac pathophysiology and serves as an early contributor to cardiomyocyte proliferation.

Cardiac regeneration: Pre-existing cardiomyocyte as the hub of novel signaling pathway

In the mammalian heart, cardiomyocytes are forced to withdraw from the cell cycle shortly after birth, limiting the ability of the heart to regenerate and repair. The development of multimodal regulation of cardiac proliferation has verified that pre-existing cardiomyocyte proliferation is an essential driver of cardiac renewal. With the continuous development of genetic lineage tracking technology, it has been revealed that cell cycle activity produces polyploid cardiomyocytes during the embryonic, juvenile, and adult stages of cardiogenesis, but newly formed mononucleated diploid cardiomyocytes also elevated sporadically during myocardial infarction. It implied that adult cardiomyocytes have a weak regenerative capacity under the condition of ischemia injury, which offers hope for the clinical treatment of myocardial infarction. However, the regeneration frequency and source of cardiomyocytes are still low, and the mechanism of regulating cardiomyocyte proliferation remains further explained. It is noteworthy to explore what force triggers endogenous cardiomyocyte proliferation and heart regeneration. Here, we focused on summarizing the recent research progress of emerging endogenous key modulators and crosstalk with other signaling pathways and furnished valuable insights into the internal mechanism of heart regeneration. In addition, myocardial transcription factors, non-coding RNAs, cyclins, and cell cycle-dependent kinases are involved in the multimodal regulation of pre-existing cardiomyocyte proliferation. Ultimately, awakening the myocardial proliferation endogenous modulator and regeneration pathways may be the final battlefield for the regenerative therapy of cardiovascular diseases.

FAM64A aggravates proliferation, invasion, lipid droplet formation, and chemoresistance in gastric cancer: A biomarker for aggressiveness and a gene therapy target

FAM64A is a mitogen-induced regulator of the metaphase and anaphase transition. Here, we found that FAM64A messenger RNA (mRNA) and protein expression levels were higher in gastric cancer tissue than in normal mucosa (p < .05). FAM64A methylation was negatively correlated with FAM64A mRNA expression (p < .05). The differentially expressed genes of FAM64A were mainly involved in digestion, potassium transporting or exchanging ATPase, contractile fibers, endopeptidase, and pancreatic secretion (p < .05). The FAM64A-related genes were principally categorized into ubiquitin-mediated proteolysis, cell cycle, chromosome segregation and mitosis, microtubule binding and organization, metabolism of amino acids, cytokine receptors, lipid droplet, central nervous system, and collagen trimer (p < .05). FAM64A protein expression was lower in normal gastric mucosa than intestinal metaplasia, adenoma, and primary cancer (p < .05), negatively correlated with older age, T stage, lymphatic and venous invasion, tumor, node, metastasis stage, and dedifferentiation (p < .05), and associated with a favorable overall survival of gastric cancer patients. FAM64A overexpression promoted proliferation, antiapoptosis, migration, invasion, and epithelial-mesenchymal transition via the EGFR/Akt/mTOR/NF-κB, while the opposite effect was observed for FAM64A knockdown. FAM64A also induced chemoresistance directly or indirectly through lipid droplet formation via ING5. These results suggested that upregulation of FAM64A expression might induce aggressive phenotypes, leading to gastric carcinogenesis and its subsequent progression. Thus, FAM64A could be regarded as a prognosis biomarker and a target for gene therapy.

Comparative Analysis of Heart Regeneration: Searching for the Key to Heal the Heart-Part II: Molecular Mechanisms of Cardiac Regeneration

Cardiovascular diseases are the leading cause of death worldwide, among which ischemic heart disease is the most representative. Myocardial infarction results from occlusion of a coronary artery, which leads to an insufficient blood supply to the myocardium. As it is well known, the massive loss of cardiomyocytes cannot be solved due the limited regenerative ability of the adult mammalian hearts. In contrast, some lower vertebrate species can regenerate the heart after an injury; their study has disclosed some of the involved cell types, molecular mechanisms and signaling pathways during the regenerative process. In this 'two parts' review, we discuss the current state-of-the-art of the main response to achieve heart regeneration, where several processes are involved and essential for cardiac regeneration.

eSPRESSO: topological clustering of single-cell transcriptomics data to reveal informative genes for spatio-temporal architectures of cells

BACKGROUND

Bioinformatics capability to analyze spatio-temporal dynamics of gene expression is essential in understanding animal development. Animal cells are spatially organized as functional tissues where cellular gene expression data contain information that governs morphogenesis during the developmental process. Although several computational tissue reconstruction methods using transcriptomics data have been proposed, those methods have been ineffective in arranging cells in their correct positions in tissues or organs unless spatial information is explicitly provided.

RESULTS

This study demonstrates stochastic self-organizing map clustering with Markov chain Monte Carlo calculations for optimizing informative genes effectively reconstruct any spatio-temporal topology of cells from their transcriptome profiles with only a coarse topological guideline. The method, eSPRESSO (enhanced SPatial REconstruction by Stochastic Self-Organizing Map), provides a powerful in silico spatio-temporal tissue reconstruction capability, as confirmed by using human embryonic heart and mouse embryo, brain, embryonic heart, and liver lobule with generally high reproducibility (average max. accuracy = 92.0%), while revealing topologically informative genes, or spatial discriminator genes. Furthermore, eSPRESSO was used for temporal analysis of human pancreatic organoids to infer rational developmental trajectories with several candidate 'temporal' discriminator genes responsible for various cell type differentiations.

CONCLUSIONS

eSPRESSO provides a novel strategy for analyzing mechanisms underlying the spatio-temporal formation of cellular organizations.

Cell Cycle-Related FAM64A Could be Activated by TGF-β Signaling to Promote Glioma Progression

Gliomas are aggressive brain tumors characterized by uncontrolled cell proliferation. FAM64A, a cell cycle-related gene, has been found to promote cell proliferation in various tumors, including gliomas. However, the regulatory mechanism and clinical significance of FAM64A in gliomas remain unclear. In this study, we investigated FAM64A expression in gliomas with different grades and constructed FAM64A silenced cell lines to study its functions. Our results demonstrated that FAM64A was highly expressed in glioblastoma (P < 0.001) and associated with a poor prognosis (P < 0.001). Expression profiles at the single-cell resolution indicated FAM64A could play a role in a cell-cycle-dependent way to promote glioma cell proliferation. We further observed that FAM64A silencing in glioma cells resulted in disrupted proliferation and migration ability, and increased cell accumulation in the G2/M phase (P = 0.034). Additionally, TGF-β signaling upregulates FAM64A expression, and SMAD4 and FAM64A co-localize in high-grade glioma tissues. We found FAM64A knockdown inhibited TGF-β-induced epithelial-mesenchymal transition in glioma. Our findings suggest that FAM64A could serve as a diagnostic and therapeutic target in gliomas.

Proliferation and Maturation: Janus and the Art of Cardiac Tissue Engineering

During cardiac development and morphogenesis, cardiac progenitor cells differentiate into cardiomyocytes that expand in number and size to generate the fully formed heart. Much is known about the factors that regulate initial differentiation of cardiomyocytes, and there is ongoing research to identify how these fetal and immature cardiomyocytes develop into fully functioning, mature cells. Accumulating evidence indicates that maturation limits proliferation and conversely proliferation occurs rarely in cardiomyocytes of the adult myocardium. We term this oppositional interplay the proliferation-maturation dichotomy. Here we review the factors that are involved in this interplay and discuss how a better understanding of the proliferation-maturation dichotomy could advance the utility of human induced pluripotent stem cell-derived cardiomyocytes for modeling in 3-dimensional engineered cardiac tissues to obtain truly adult-level function.

Postnatal expression of cell cycle promoter Fam64a causes heart dysfunction by inhibiting cardiomyocyte differentiation through repression of Klf15

Introduction of fetal cell cycle genes into damaged adult hearts has emerged as a promising strategy for stimulating proliferation and regeneration of postmitotic adult cardiomyocytes. We have recently identified Fam64a as a fetal-specific cell cycle promoter in cardiomyocytes. Here, we analyzed transgenic mice maintaining cardiomyocyte-specific postnatal expression of Fam64a when endogenous expression was abolished. Despite an enhancement of cardiomyocyte proliferation, these mice showed impaired cardiomyocyte differentiation during postnatal development, resulting in cardiac dysfunction in later life. Mechanistically, Fam64a inhibited cardiomyocyte differentiation by repressing Klf15, leading to the accumulation of undifferentiated cardiomyocytes. In contrast, introduction of Fam64a in differentiated adult wildtype hearts improved functional recovery upon injury with augmented cell cycle and no dedifferentiation in cardiomyocytes. These data demonstrate that Fam64a inhibits cardiomyocyte differentiation during early development, but does not induce de-differentiation in once differentiated cardiomyocytes, illustrating a promising potential of Fam64a as a cell cycle promoter to attain heart regeneration.

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Overexpression of cell cycle promoter Fam64a in cardiomyocytes causes heart failure

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Fam64a inhibits cardiomyocyte differentiation during development by repressing Klf15

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Transient and local induction of Fam64a in adult hearts improves recovery upon injury

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Fam64a activates cardiomyocyte cell cycle without dedifferentiation upon injury

OUP accepted manuscript

The adult mammalian heart is recalcitrant to regeneration after injury, in part due to the postmitotic nature of cardiomyocytes. Accumulating evidence suggests that cardiomyocyte proliferation in fetal or neonatal mammals and in regenerative non-mammalian models depends on a conducive metabolic state. Results from numerous studies in adult hearts indicate that conditions of relatively low fatty acid oxidation, low reactive oxygen species generation, and high glycolysis are required for induction of cardiomyocyte proliferation. Glycolysis appears particularly important because it provides branchpoint metabolites for several biosynthetic pathways that are essential for synthesis of nucleotides and nucleotide sugars, amino acids, and glycerophospholipids, all of which are required for daughter cell formation. In addition, the proliferative cardiomyocyte phenotype is supported in part by relatively low oxygen tensions and through the actions of critical transcription factors, coactivators, and signaling pathways that promote a more glycolytic and proliferative cardiomyocyte phenotype, such as hypoxia inducible factor 1α (Hif1α), Yes-associated protein (Yap), and ErbB2. Interventions that inhibit glycolysis or its integrated biosynthetic pathways almost universally impair cardiomyocyte proliferative capacity. Furthermore, metabolic enzymes that augment biosynthetic capacity such as phosphoenolpyruvate carboxykinase 2 and pyruvate kinase M2 appear to be amplifiers of cardiomyocyte proliferation. Collectively, these studies suggest that acquisition of a glycolytic and biosynthetic metabolic phenotype is a sine qua non of cardiomyocyte proliferation. Further knowledge of the regulatory mechanisms that control substrate partitioning to coordinate biosynthesis with energy provision could be leveraged to prompt or augment cardiomyocyte division and to promote cardiac repair.

Cardiac Remodeling and Repair: Recent Approaches, Advancements, and Future Perspective

The limited ability of mammalian adult cardiomyocytes to proliferate following an injury to the heart, such as myocardial infarction, is a major factor that results in adverse fibrotic and myocardial remodeling that ultimately leads to heart failure. The continued high degree of heart failure-associated morbidity and lethality requires the special attention of researchers worldwide to develop efficient therapeutics for cardiac repair. Recently, various strategies and approaches have been developed and tested to extrinsically induce regeneration and restoration of the myocardium after cardiac injury have yielded encouraging results. Nevertheless, these interventions still lack adequate success to be used for clinical interventions. This review highlights and discusses both cell-based and cell-free therapeutic approaches as well as current advancements, major limitations, and future perspectives towards developing an efficient therapeutic method for cardiac repair.

Pan-Cancer Analysis of PIMREG as a Biomarker for the Prognostic and Immunological Role

Phosphatidylinositol binding clathrin assembly protein interacting mitotic regulator (PIMREG) localizes to the nucleus and can significantly elevate the nuclear localization of clathrin assembly lymphomedullary leukocythemia gene. Although there is some evidence to support an important action for PIMREG in the occurrence and development of certain cancers, currently no pan-cancer analysis of PIMREG is available. Therefore, we intended to estimate the prognostic predictive value of PIMREG and to explore its potential immune function in 33 cancer types. By using a series of bioinformatics approaches, we extracted and analyzed datasets from Oncomine, The Cancer Genome Atlas, Cancer Cell Lineage Encyclopedia (CCLE) and the Human Protein Atlas (HPA), to explore the underlying carcinogenesis of PIMREG, including relevance of PIMREG to prognosis, microsatellite instability (MSI), tumor mutation burden (TMB), tumor microenvironment (TME) and infiltration of immune cells in various types of cancer. Our findings indicate that PIMREG is highly expressed in at least 24 types of cancer, and is negatively correlated with prognosis in major cancer types. In addition, PIMREG expression was correlated with TMB in 24 cancers and with MSI in 10 cancers. We revealed that PIMREG is co-expressed with genes encoding major histocompatibility complex, immune activation, immune suppression, chemokine and chemokine receptors. We also found that the different roles of PIMREG in the infiltration of different immune cell types in different tumors. PIMREG can potentially influence the etiology or pathogenesis of cancer by acting on immune-related pathways, chemokine signaling pathway, regulation of autophagy, RIG-I like receptor signaling pathway, antigen processing and presentation, FC epsilon RI pathway, complement and coagulation cascades, T cell receptor pathway, NK cell mediated cytotoxicity and other immune-related pathways. Our study suggests that PIMREG can be applied as a prognostic marker in a variety of malignancies because of its role in tumorigenesis and immune infiltration.

Tumor-promoting function of PIMREG in glioma by activating the β-catenin pathway

Glioma is the most common primary brain tumor in adults with an adverse prognosis and obscure pathogenesis. PICALM interacting mitotic regulator protein (PIMREG) functions as an oncogene in multiple types of cancer, but its function in glioma remains unknown. The Gene Expression Profiling Interactive Analysis 2 (GEPIA2, http://gepia2.cancer-pku.cn/#index) showed that PIMREG expression in the glioma tissues was higher than that in normal brain tissues. Herein, cell counting kit-8 assay and flow cytometry analysis exhibited that overexpression of PIMREG significantly promoted the proliferation of glioma cells and the transition from G1 phase of the cell cycle to S phase. Wound-healing and transwell assays showed that overexpression of PIMREG markedly enhanced the migration and invasion of glioma cells. Western blot analysis revealed that overexpression of PIMREG increased the expression of cyclin D1, cyclin E, Vimentin, matrix metalloproteinase (MMP)-2, and MMP-9, but reduced the expression of E-cadherin. In addition, overexpression of PIMREG activated the β-catenin signaling pathway, as evidenced by the increased total and nuclear expression of β-catenin and the up-regulated expression of its downstream target c-myc. Furthermore, immunofluorescence staining further indicated the increased nuclear translocation of β-catenin in PIMREG-overexpressing cells. However, knockdown of PIMREG exerted opposite effects on glioma cells. Blockade of the β-catenin signaling by ICG-001 markedly impeded the promoting effects of PIMREG on glioma cell proliferation and invasion. In conclusion, PIMREG acts as a tumor promoter in glioma at least partly via activating the β-catenin signaling pathway. This study provides new insights into the molecular mechanism for glioma pathogenesis and treatment.

High expression of PIMREG predicts poor survival outcomes and is correlated with immune infiltrates in lung adenocarcinoma

Background

PIMREG is upregulated in multiple cancer types. However, the potential role of PIMREG in lung adenocarcinoma (LUAD) remains unclear. The present study aimed to explore its clinical significance in LUAD.

Methods

Using the Cancer Genome Atlas (TCGA) databases, we obtained 513 samples of LUAD and 59 normal samples from the Cancer Genome Atlas (TCGA) databases to analyze the relationship between PIMREG and LUAD. We used t and Chi-square tests to evaluate the level of expression of PIMREG and its clinical implication in LUAD. The prognostic value of PIMREG in LUAD was identified through the Kaplan–Meier method, Cox regression analysis, and nomogram. Gene set enrichment analysis (GSEA) and single-sample gene set enrichment analysis (ssGSEA) were performed to screen biological pathways and analyze the correlation of the immune infiltrating level with the expression of PIMREG in LUAD.

Results

PIMREG was highly expressed in patients with LUAD. Specifically, the level of PIMREG gradually increased from pathological stage I to IV. Further, we validated the higher expression of PIMREG expressed in LUAD cell lines. Moreover, PIMREG had a high diagnostic value, with an -AUC of 0.955. Kaplan–Meier survival and Cox regression analyses revealed that the high expression of PIMREG was independently associated with poor clinical outcomes. In our prognostic nomogram, the expression of PIMREG implied a significant prognostic value. Gene set enrichment analysis (GSEA) identified that the high expression PIMREG phenotype was involved in the mitotic cell cycle, mRNA splicing, DNA repair, Rho GTPase signaling, TP53 transcriptional regulation, and translation pathways. Next, we also explored the correlation of PIMREG and tumor-immune interactions and found a negative correlation between PIMREG and the immune infiltrating level of T cells, macrophages, B cells, dendritic cells (DCs) , and CD8⁺ T cells in LUAD.

Conclusions

High levels of PIMREG correlated with poor prognosis and immune infiltrates in LUAD.

Metabolic regulation of cardiac regeneration: roles of hypoxia, energy homeostasis, and mitochondrial dynamics

The adult mammalian heart cannot regenerate after myocardial injury because most cardiomyocytes lack the ability to proliferate. In contrast, cardiomyocytes of vertebrates such as zebrafish and urodele amphibians, but also those of fetal and early neonatal mammals, maintain the ability to proliferate and therefore support regeneration of injured tissue and recovery of cardiac function. Whether evolutionarily conserved regulatory mechanisms of cardiomyocyte proliferation exist and, if so, whether they are modifiable to allow cardiac regeneration in adult mammals are questions of great scientific and medical interest. Environmental hypoxia, hypoxia-induced cellular signaling, and mitochondrial metabolism have recently emerged as key regulators of the cardiomyocyte cell cycle and cardiac regeneration in vertebrates. In this review, we address the cardiac regenerative capacity of several model animals and discuss potential strategies related to hypoxia and mitochondrial metabolism for induction of therapeutic heart regeneration.

Identification of Immune-Related Therapeutically Relevant Biomarkers in Breast Cancer and Breast Cancer Stem Cells by Transcriptome-Wide Analysis: A Clinical Prospective Study

Cancer stem cells (CSCs) represent a subset of tumor cells that are responsible for recurrence and metastasis of tumors. These cells are resistant to radiotherapy and chemotherapy. Immunotherapeutic strategies that target CSCs specifically have provided initial results; however, the mechanism of action of these strategies is unclear. The data were requested from The Cancer Genome Atlas and Genotype-Tissue Expression, followed with the survival analysis and weighted gene co-expression network analysis to detect survival and stemness related genes. Patients were divided into three groups based on their immune status by applying single sample GSEA (ssGSEA) with proven dependability by ESTIMATE analysis. The filtered key genes were analyzed using oncomine, GEPIA, HPA, qRT-PCR, and functional analysis. Patients in a group with a higher stemness and a lower immune infiltration showed a worse overall survival probability, stemness and immune infiltration characteristics of breast cancer progressed in a non-linear fashion. Thirteen key genes related to stemness and immunity were identified and the functional analysis indicated their crucial roles in cell proliferation and immune escape strategies. The qRT-PCR results showed that the expression of PIMREG and MTFR2 differed in different stages of patients. Our study revealed a promising potential for CSC-target immunotherapy in the early stage of cancer and a probable value for PIMREG and MTFR2 as biomarkers and targets for immunotherapy.

Identifying breast cancer subtypes associated modules and biomarkers by integrated bioinformatics analysis

Breast cancer is the most common form of cancer afflicting women worldwide. Patients with breast cancer of different molecular classifications need varied treatments. Since it is known that the development of breast cancer involves multiple genes and functions, identification of functional gene modules (clusters of the functionally related genes) is indispensable as opposed to isolated genes, in order to investigate their relationship derived from the gene co-expression analysis. In total, 6315 differentially expressed genes (DEGs) were recognized and subjected to the co-expression analysis. Seven modules were screened out. The blue and turquoise modules have been selected from the module trait association analysis since the genes in these two modules are significantly correlated with the breast cancer subtypes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment show that the blue module genes engaged in cell cycle, DNA replication, p53 signaling pathway, and pathway in cancer. According to the connectivity analysis and survival analysis, 8 out of 96 hub genes were filtered and have shown the highest expression in basal-like breast cancer. Furthermore, the hub genes were validated by the external datasets and quantitative real-time PCR (qRT-PCR). In summary, hub genes of Cyclin E1 (CCNE1), Centromere Protein N (CENPN), Checkpoint kinase 1 (CHEK1), Polo-like kinase 1 (PLK1), DNA replication and sister chromatid cohesion 1 (DSCC1), Family with sequence similarity 64, member A (FAM64A), Ubiquitin Conjugating Enzyme E2 C (UBE2C) and Ubiquitin Conjugating Enzyme E2 T (UBE2T) may serve as the prognostic markers for different subtypes of breast cancer.

FAM64A: A Novel Oncogenic Target of Lung Adenocarcinoma Regulated by Both Strands of miR-99a (miR-99a-5p and miR-99a-3p)

Lung adenocarcinoma (LUAD) is the most aggressive cancer and the prognosis of these patients is unfavorable. We revealed that the expression levels of both strands of miR-99a (miR-99a-5p and miR-99a-3p) were significantly suppressed in several cancer tissues. Analyses of large The Cancer Genome Atlas (TCGA) datasets showed that reduced miR-99a-5p or miR-99a-3p expression is associated with worse prognoses in LUAD patients (disease-free survival (DFS): p = 0.1264 and 0.0316; overall survival (OS): p = 0.0176 and 0.0756, respectively). Ectopic expression of these miRNAs attenuated LUAD cell proliferation, suggesting their tumor-suppressive roles. Our in silico analysis revealed 23 putative target genes of pre-miR-99a in LUAD cells. Among these targets, high expressions of 19 genes were associated with worse prognoses in LUAD patients (OS: p < 0.05). Notably, FAM64A was regulated by both miR-99a-5p and miR-99a-3p in LUAD cells, and its aberrant expression was significantly associated with poor prognosis in LUAD patients (OS: p = 0.0175; DFS: p = 0.0276). FAM64A knockdown using siRNAs suggested that elevated FAM64A expression contributes to cancer progression. Aberrant FAM64A expression was detected in LUAD tissues by immunostaining. Taken together, our miRNA-based analysis might be effective for identifying prognostic and therapeutic molecules in LUAD.

Novel insights into cardiac regeneration based on differential fetal and adult ovine heart transcriptomic analysis

The adult mammalian cardiomyocyte has a very limited capacity to reenter the cell cycle and advance into mitosis. Therefore, diseases characterized by lost contractile tissue usually evolve into myocardial remodeling and heart failure. Analyzing the cardiac transcriptome at different developmental stages in a large mammal closer to the human than laboratory rodents may serve to disclose positive and negative cardiomyocyte cell cycle regulators potentially targetable to induce cardiac regeneration in the clinical setting. Thus we aimed at characterizing the transcriptomic profiles of the early fetal, late fetal, and adult sheep heart by employing RNA-seq technique and bioinformatic analysis to detect protein-encoding genes that in some of the stages were turned off, turned on, or differentially expressed. Genes earlier proposed as positive cell cycle regulators such as cyclin A, cdk2, meis2, meis3, and PCNA showed higher expression in fetal hearts and lower in AH, as expected. In contrast, genes previously proposed as cell cycle inhibitors, such as meis1, p16, and sav1, tended to be higher in fetal than in adult hearts, suggesting that these genes are involved in cell processes other than cell cycle regulation. Additionally, we described Gene Ontology (GO) enrichment of different sets of genes. GO analysis revealed that differentially expressed gene sets were mainly associated with metabolic and cellular processes. The cell cycle-related genes fam64a, cdc20, and cdk1, and the metabolism-related genes pitx and adipoq showed strong differential expression between fetal and adult hearts, thus being potent candidates to be targeted in human cardiac regeneration strategies.NEW & NOTEWORTHY We characterized the transcriptomic profiles of the fetal and adult sheep hearts employing RNAseq technique and bioinformatic analyses to provide sets of transcripts whose variation in expression level may link them to a specific role in cell cycle regulation. It is important to remark that this study was performed in a large mammal closer to humans than laboratory rodents. In consequence, the results can be used for further translational studies in cardiac regeneration.

FAM64A Promotes Osteosarcoma Cell Growth and Metastasis and Is Mediated by miR-493

Aberrant expression of FAM64A was correlated with cell proliferation in various cancer types. We examined the expression of FAM64A and the upstream gene miR-493 in OS. The functions of miR-493 were revealed through extensive experiments. We found an increase of FAM64A gene and protein in OS tissues. Overexpression of FAM64A resulted in promoting tumor proliferation, migration, and invasion. The miR-493 targeted and negatively regulated FAM64A. Our data showed that upregulation of FAM64A in OS correlated with poor prognosis.

PIMREG, a Marker of Proliferation, Facilitates Aggressive Development of Cholangiocarcinoma Cells Partly Through Regulating Cell Cycle-Related Markers

BACKGROUND

Phosphatidylinositol binding clathrin assembly protein interacting mitotic regulator (PIMREG) is a protein associated with cell proliferation. Its aberrant expression was reported to be correlated with the development in multiple tumors. However, its role in cholangiocarcinoma (CAA) has not yet been evaluated in detail.

METHODS

Data were acquired from the public TCGA database for evaluating the expression pattern of PIMREG and assessing its clinical relevance as well as its correlation with overall survival. RBE and HUH28 cell lines were selected to perform loss- and gain-of-function of PIMREG assays respectively. Quantitative real-time PCR (RT-qPCR) and western blot analyses were used to measure the mRNA and protein levels of PIMREG. Cell Counting Kit-8, colony formation tests, and Transwell assays served to measure the effect of PIMREG on the proliferative, invasive and migratory capacities of CAA cells, appropriately. Gene set enrichment analysis (GSEA) was conducted to identify PIMREG associated gene set, which was further confirmed by western blot.

RESULTS

PIMREG was found to be highly expressed in CAA tissues and cell lines according to the public dataset and RT-qPCR analysis, and negatively related to the prognosis of patients with CAA. Moreover, knockdown of PIMREG suppressed and overexpression of PIMREG promoted the proliferation, invasion and migration of CAA cells. Furthermore, GSEA revealed that high PIMREG expression was positively associated with cell cycle signaling. And the next western blot analysis demonstrated that silencing PIMREG resulted in a reduction on the levels of p-CDK1, CCNE1, and CCNB1, whereas PIMREG overexpression led to an opposite result.

CONCLUSION

The results suggested that PIMREG facilitates the growth, invasion and migration of CAA cells partly by regulating the cell cycle relative biomarkers, revealing that PIMREG may be a crucial molecule in the progression of CAA.

Knockdown of FAM64A suppresses proliferation and migration of breast cancer cells

BACKGROUND

FAM64A is a mitotic regulator promoting cell metaphase-anaphase transition, and it is frequently reported to be highly expressed in cancer cells. However, the role of FAM64A in human breast cancer (BrC) is poorly studied.

METHODS

The expression of FAM64A mRNA in BrC samples was determined by RT-qPCR assay and TCGA database mining. Kaplan-Meier plotter was used to analyze whether FAM64A expression impacted prognosis. Then, the expression of FAM64A was silenced using RNA interference. Cell-counting assay, colony formation assay and flow cytometry assay were conducted to detect proliferation; transwell migration assay, EMT-related proteins expression (E-cadherin, N-cadherin and vimentin), and EMT-related transcription factors mRNA expression (Snail, Twist, Slug) were conducted to evaluate the migration ability.

RESULTS

FAM64A was highly expressed in human BrC samples, which was negatively associated with poor survival time. Analysis of FAM64A expression in BrC cell lines demonstrated that the expression of FAM64A was significantly correlated with the proliferation rate and migration ability of BrC cells. Indeed, knockdown of FAM64A suppressed the proliferation of MDA-MB-231 and MCF-7 cells. Importantly, we also found that silencing of FAM64A inhibited the migration of BrC cells via impeding epithelial-mesenchymal transition.

CONCLUSIONS

Our findings suggest that FAM64A plays an important role in the proliferation and migration of BrC cells, which might serve as a potential target for BrC treatment.

FAM64A positively regulates STAT3 activity to promote Th17 differentiation and colitis-associated carcinogenesis

STAT3 is a transcription factor that plays central roles in various physiological processes, including differentiation of Th cells. Its deregulation results in serious diseases, including inflammatory diseases and cancer. The mechanisms related to how STAT3 activity is regulated remain enigmatic. Here we show that overexpression of FAM64A potentiates IL-6-induced activation of STAT3 and expression of downstream target genes, whereas deficiency of FAM64A has the opposite effects. FAM64A interacts with STAT3 in the nucleus and regulates binding of STAT3 to the promoters of its target genes. Deficiency of Fam64a significantly impairs differentiation of Th17 but not Th1 or induced regulatory T cells (iTreg). In addition, Fam64a deficiency attenuates experimental autoimmune encephalomyelitis (EAE) and dextran sulfate sodium (DSS)-induced colitis, which is correlated with decreased differentiation of Th17 cells and production of proinflammatory cytokines. Furthermore, Fam64a deficiency suppresses azoxymethane (AOM)/DSS-induced colitis-associated cancer (CAC) in mice. These findings suggest that FAM64A regulates Th17 differentiation and colitis and inflammation-associated cancer by modulating transcriptional activity of STAT3.

PKC and PKN in heart disease

The protein kinase C (PKC) and closely related protein kinase N (PKN) families of serine/threonine protein kinases play crucial cellular roles. Both kinases belong to the AGC subfamily of protein kinases that also include the cAMP dependent protein kinase (PKA), protein kinase B (PKB/AKT), protein kinase G (PKG) and the ribosomal protein S6 kinase (S6K). Involvement of PKC family members in heart disease has been well documented over the years, as their activity and levels are mis-regulated in several pathological heart conditions, such as ischemia, diabetic cardiomyopathy, as well as hypertrophic or dilated cardiomyopathy. This review focuses on the regulation of PKCs and PKNs in different pathological heart conditions and on the influences that PKC/PKN activation has on several physiological processes. In addition, we discuss mechanisms by which PKCs and the closely related PKNs are activated and turned-off in hearts, how they regulate cardiac specific downstream targets and pathways, and how their inhibition by small molecules is explored as new therapeutic target to treat cardiomyopathies and heart failure.

Aberrant FAM64A mRNA expression is an independent predictor of poor survival in pancreatic cancer

FAM64A, a marker of cell proliferation, has been investigated as a potential biomarker in several cancers. In the present study, we examined the value of FAM64A expression in the diagnosis and prognosis of pancreatic cancer through bioinformatics analysis of data obtained from The Cancer Genome Atlas (TCGA) database. The diagnostic value of FAM64A expression in pancreatic cancer tissue was deteremined through receiver operating characteristic (ROC) curve analysis, and based on the obtained cut-off value, patients were divided into two groups (high FAM64A expression and low FAM64A expression). Chi-square and Fisher exact tests were applied to identify associations between FAM64A expression and clinical features. Moreover, the effect of FAM64A expression in the survival of pancreatic cancer patients was observed by Kaplan-Meier and Cox analyses. Gene set enrichment analysis (GSEA) was performed using the TCGA dataset. Our results showed that high FAM64A expression in pancreatic cancer was associated with survival status, overall survival (OS), and recurrence. The area under the ROC curve was 0.736, which indicated modest diagnostic value. Patients with higher FAM64A expression had significantly shorter OS and recurrence-free survival (RFS) times. Multivariate survival analysis demonstrated that high FAM64A expression was an independent risk factor for OS and RFS. GSEA identified mitotic spindles, myc targets, MTORC1 signaling, G2M checkpoint, E2F targets, DNA repair, glycolysis and unfolded protein response as differentially enriched with the high FAM64A expression phenotype. In conclusion, high FAM64A mRNA expression is an independent risk factor for poor prognosis in pancreatic cancer.

Patent highlights June-July 2018

A snapshot of noteworthy recent developments in the patent literature of relevance to pharmaceutical and medical research and development.

Nuclear connectin novex-3 promotes proliferation of hypoxic foetal cardiomyocytes

Loss of cardiomyocyte proliferative capacity after birth is a major obstacle for therapeutic heart regeneration in adult mammals. We and others have recently shown the importance of hypoxic in utero environments for active foetal cardiomyocyte proliferation. Here, we report the unexpected expression of novex-3, the short splice variant of the giant sarcomeric protein connectin (titin), in the cardiomyocyte nucleus specifically during the hypoxic foetal stage in mice. This nuclear localisation appeared to be regulated by the N-terminal region of novex-3, which contains the nuclear localisation signal. Importantly, the nuclear expression of novex-3 in hypoxic foetal cardiomyocytes was repressed at the postnatal stage following the onset of breathing and the resulting elevation of oxygen tension, whereas the sarcomeric expression remained unchanged. Novex-3 knockdown in foetal cardiomyocytes repressed cell cycle-promoting genes and proliferation, whereas novex-3 overexpression enhanced proliferation. Mechanical analysis by atomic force microscopy and microneedle-based tensile tests demonstrated that novex-3 expression in hypoxic foetal cardiomyocytes contributes to the elasticity/compliance of the nucleus at interphase and facilitates proliferation, by promoting phosphorylation-induced disassembly of multimer structures of nuclear lamins. We propose that novex-3 has a previously unrecognised role in promoting cardiomyocyte proliferation specifically at the hypoxic foetal stage.