G1-S Phase Research Articles

In silico screening, synthesis, characterization and biological evaluation of novel anticancer agents as potential COX-2 inhibitors.

Cyclooxygenase enzyme is frequently overexpressed in various types of cancer and found to play a crucial role in poor prognosis in cancer patients. In current research, we have reported the new COX-2 inhibitors for cancer treatment using computer-aided drug design and experimental validation. A total of 12,795 compounds from the different databases were used to screen against the COX-2 enzyme. It perceived three new compounds with better binding affinity to the enzyme. Afterwards, physicochemical properties and in silico bioactivity were assessed for efficacy, safety, and structural features required for binding. The molecules were synthesized and confirmed by spectroscopic techniques. Later on, molecules were evaluated for their anti-cancer activity using MCF-7, MDA-MB-231 and SiHa cancer cell lines. Compound ZINC5921547 and ZINC48442590 (4a, and 4b) reduced the MCF-7, MDA-MB-231, and SiHa cells proliferation potently than parent compounds. The PG-E2 estimation shown, both compounds act through the COX-2 PGE2 axis. Compound 4a and 4b block the cell cycle at G1-S phase and induce cancer cell death. We concluded that compounds 4a and 4b effectively promotes cancer cell death via COX-2 PGE2 axis, and further in vivo studies can be evaluated for development in both compounds as anticancer agents. The compilation of this information will help us to generate better outcome through robust computational methods. The high-quality experimental results may pave the way for identifying effective drug candidates for cancer treatment.

SNORD6 promotes cervical cancer progression by accelerating E6-mediated p53 degradation

Small nucleolar RNAs (snoRNAs) are a class of non-coding RNAs widely distributed in eukaryotic nucleoli. In recent years, studies have revealed that snoRNAs can also participate in the occurrence and development of malignant tumors through different pathways. Cervical cancer is one of the most common malignant tumors of the female reproductive system, and the high-risk HPV virus infection is its main pathogenic mechanism. However, the outcomes in different patients with malignant tumors vary, indicating that other factors might affect the pathogenic process of cervical cancer. In this study, we screened the poor prognosis indicator SNORD6 from the TCGA database to find the snoRNA that affects the disease outcome during the pathogenesis of cervical cancer. We discovered that SNORD6 expression in cervical cancer tissues was higher than that in normal cervical tissues. Cell phenotype experiments revealed that the knockdown of SNORD6 retarded cell proliferation and plate clone formation. Furthermore, G1-S phase cell cycle arrest was induced, DNA synthesis was decreased, cell migration and invasion were reduced, while the level of apoptosis increased, whereas the opposite results were obtained after SNORD6 overexpression. Moreover, after intratumoral injection of ASO-SNORD6, the tumor growth rate slowed down, and the tumor volume decreased compared with the control group. In the mechanism study, we found that SNORD6 concurrently acted as a binding “hub” to promote the formation of the tumor suppressor protein p53 degradation complex E6-E6AP-p53. This reaction enhanced the ubiquitination and degradation of p53, thus influenced the regulation of p53 activities in the cell cycle and apoptosis. This study preliminarily clarified the biological role and specific mechanism of SNORD6 in the occurrence of cervical cancer, broadening the basic theoretical research of ovarian cancer and may provide a new perspective on the diagnosis and treatment of cervical cancer.

A genome-wide screen reveals that Dyrk1A kinase promotes nucleotide excision repair by preventing aberrant overexpression of cyclin D1 and p21

Nucleotide excision repair (NER) eliminates highly genotoxic solar UV-induced DNA photoproducts that otherwise stimulate malignant melanoma development. Here, a genome-wide loss-of-function screen, coupling CRISPR/Cas9 technology with a flow cytometry-based DNA repair assay, was used to identify novel genes required for efficient NER in primary human fibroblasts. Interestingly, the screen revealed multiple genes encoding proteins, with no previously known involvement in UV damage repair, that significantly modulate NER uniquely during S phase of the cell cycle. Among these, we further characterized Dyrk1A, a dual specificity kinase that phosphorylates the proto-oncoprotein cyclin D1 on threonine 286 (T286), thereby stimulating its timely cytoplasmic relocalization and proteasomal degradation, which is required for proper regulation of the G1-S phase transition and control of cellular proliferation. We demonstrate that in UV-irradiated HeLa cells, depletion of Dyrk1A leading to overexpression of cyclin D1 causes inhibition of NER uniquely during S phase and reduced cell survival. Consistently, expression/nuclear accumulation of nonphosphorylatable cyclin D1 (T286A) in melanoma cells strongly interferes with S phase NER and enhances cytotoxicity post-UV. Moreover, the negative impact of cyclin D1 (T286A) overexpression on repair is independent of cyclin-dependent kinase activity but requires cyclin D1-dependent upregulation of p21 expression. Our data indicate that inhibition of NER during S phase might represent a previously unappreciated noncanonical mechanism by which oncogenic cyclin D1 fosters melanomagenesis.

MESP1-knockdown inhibits the proliferation and epithelial mesenchymal transition of hepatocellular carcinoma and enhances the tumor-suppressive effect of 5-fluorouracil

Primary liver hepatocellular carcinoma (HCC) is the third most deadly malignancy worldwide,in part, because it is often diagnosed at an advanced stage. Thus, molecular markers are needed to aid in the early diagnosis and treatment of HCC. Expression of abnormal mesoderm posterior-1 (MESP1) promotes tumorigenesis; however,its role in the regulation of HCC proliferation, apoptosis,and invasion is unknown. Here,we analyzed data in The Cancer Genome Atlas (TCGA)and Genotype Tissue Expression (GTEx) databases on the pan-cancer expression of MESP1 and its relationship with clinical characteristics and prognosis of patients with HCC. The expression of MESP1 was measured in 48 HCC tissues using immunohistochemical staining,and the results were correlated with clinical stage, tumor differentiation, tumor size,and metastasis. MESP1 expression was downregulated using small interfering RNA (siRNA) in the HCC cell lines HepG2 and Hep3B,and cell viability, proliferation,cell cycle, apoptosis,and invasion were analyzed. Finally,we also evaluated the tumor suppression effect of MESP1 downregulation combined with 5-fluorouracil (5-FU) treatment. Our results showed that MESP1 is a pan-oncogene associated with poor prognosis in patients with HCC. siRNA-induced downregulation of MESP1 expression in HepG2 and Hep3B cells exhibited downregulation of β-catenin and GSK3β expression 48h after transfection, along with an increase in apoptosis rate, arrest in the G1-S phase,and a decrease in mitochondrial membrane potential. Moreover,the expression levels of c-Myc, PARP1, bcl2, Snail1, MMP9, and immune checkpoint genes (TIGIT, CTLA4,LAG3,CD274,and PDCD1) were downregulated, while those of caspase3 and E-cadherin were upregulated. Tumor cells also showed decreased migration ability. Furthermore, siRNA interference of MESP1 expression combined with 5-FU-treatment of HCC cells significantly enhanced the G1-S phase block and apoptosis. MESP1 showed an aberrant high expression in HCC and was associated with poor clinical outcomes; therefore, MESP1 may be a potential target for the diagnosis and treatment of HCC.

Blockage of retinoic acid signaling via RARγ suppressed the proliferation of pancreatic cancer cells by arresting the cell cycle progression of the G1-S phase

BackgroundOur study and several studies have reported that in some cancers, including pancreatic ductal adenocarcinoma (PDAC), the expression of squamous lineage markers, such as esophagus-tissue-specific genes, correlated with a poor prognosis. However, the mechanism by which the acquisition of squamous lineage phenotypes leads to a poor prognosis remains unclear. We previously reported that retinoic acid signaling via retinoic acid receptor γ (RARγ signaling) determines the differentiation lineage into the esophageal squamous epithelium. These findings hypothesized that the activation of RARγ signaling contributed to acquiring squamous lineage phenotypes and malignant behavior in PDAC.MethodsThis study utilized public databases and immunostaining of surgical specimens to examine RARγ expression in PDAC. We evaluated the function of RARγ signaling by inhibitors and siRNA knockdown using a PDAC cell line and patient-derived PDAC organoids. The mechanism of the tumor-suppressive effects by blocking RARγ signaling was examined by a cell cycle analysis, apoptosis assays, RNA sequencing and Western blotting.ResultsRARγ expression in pancreatic intraepithelial neoplasia (PanIN) and PDAC was higher than that in the normal pancreatic duct. Its expression correlated with a poor patient prognosis in PDAC. In PDAC cell lines, blockade of RARγ signaling suppressed cell proliferation by inducing cell cycle arrest in the G1 phase without causing apoptosis. We demonstrated that blocking RARγ signaling upregulated p21 and p27 and downregulated many cell cycle genes, including cyclin-dependent kinase 2 (CDK2), CDK4 and CDK6. Furthermore, using patient-derived PDAC organoids, we confirmed the tumor-suppressive effect of RARγ inhibition and indicated the synergistic effects of RARγ inhibition with gemcitabine.ConclusionsThis study clarified the function of RARγ signaling in PDAC progression and demonstrated the tumor-suppressive effect of selective blockade of RARγ signaling against PDAC. These results suggest that RARγ signaling might be a new therapeutic target for PDAC.

Synthesis, DFT calculations, and anti-proliferative evaluation of pyrimidine and selenadiazolopyrimidine derivatives as dual Topoisomerase II and HSP90 inhibitors

Novel series of aminopyrimidines bearing a biologically active cyclohexenone 3a–f and oxo-selaneylidene moiety 4, besides selenadiazolopyrimidines (5a–e and 7), were synthesised using 5,6-diaminouracils as starting materials. Compound 3a exhibited strong anti-proliferative activity against three cell lines: HepG-2 (IC50 14.31 ± 0.83 µM), A-549 (IC50 30.74 ± 0.76 µM), and MCF-7 (IC50 27.14 ± 1.91 µM). Also, it was four times more selectively cytotoxic against WI-38 cell lines than doxorubicin. Furthermore, Topoisomerase II (IC50 4.48 ± 0.65 µM) and HSP90 (IC50 1.78 ± 0.11 µM) were both strongly inhibited in vitro by 3a. The cell cycle was halted at the G1-S phase, and total apoptotic cells were 65 times more than control Hep-G2 cells. Besides, it increased caspase-3 gene expression, triggering mitochondrial cell death. Molecular docking study indicated that it could bind to Topoisomerase II and HSP90 binding sites in an inhibitory mode. Its geometric properties were investigated using the density functional theory (DFT). Furthermore, compound 3a demonstrated in silico good oral bioavailability.

Low-Dose Non-Thermal Atmospheric Plasma Promotes the Proliferation and Migration of Human Normal Skin Cells

(1) Background: The purpose of this study was to investigate the effects of low-dose non-thermal atmospheric plasma (NTP) on the proliferation and migration of human immortalized keratinocytes (HaCaT cells) and its molecular mechanisms. (2) Methods: The effects of NTP on HaCaT cells were detected by cell viability, wound healing assay, cell cycle, mitochondrial membrane potential detection, and western blot, and the role of reactive oxygen species (ROS) content in low-dose NTP was explored. (3) Results: Results showed that the proportion of cells in G1-S phase transition, cell migration ability, and the expression of Cyclin D1 and STAT3 reached the peak at 10 s treatment group, while the cell viability and the expression of PI3K, AKT, mTOR, ERK, WNT, and β-catenin proteins reached the peak at 15 s treatment group. (4) Conclusions: These results manifested that ROS produced by low-dose NTP promoted the proliferation of HaCaT cells by activating the PI3K/AKT/mTOR signaling pathway and also promoted the migration by activating the WNT/β-catenin signaling pathway. Therefore, these results will be useful for the application of low-dose NTP in the treatment of wound healing.

Histone Deacetylase 1 Expression and Regulatory Network in Lung Adenocarcinoma Based on Data Mining and Implications for Targeted Treatment.

Histone deacetylase 1 (HDAC1) codes a protein that is a component of the histone deacetylase complex. The abnormal expression of HDAC1 is strongly correlated with cell proliferation, differentiation, transcription, and translation. Through continuous screening of genes associated with changes in lung adenocarcinoma (LUAD), gene networks are formed to explore tumor pathogenesis and new therapeutic targets. We evaluated HDAC1 gene survival analysis and its expression of LUAD using relevant websites and databases (TCGA and GEO databases). Through data mining, we determined the frequency and type of HDAC1 mutation, obtained the relevant heat map of the gene interaction network, completed the analysis of gene ontology and function enrichment, and understood the pharmaceutic of HDAC1. We found that HDAC1 expression was associated with the prognosis of patients with LUAD. In gene expression analysis, HDAC1 was highly expressed in LUAD, and the HDAC1 interaction gene network (MARCKSL, eIF3I) was closely related to cellular gene expression. Functional network analysis shows that the expression of HDAC1 is related to the monitoring point of the G1-S phase of the cell cycle and the activation of the Notch signaling pathway (CSL transcription factor), which is involved in the process of cell proliferation and differentiation and gene expression associated with new therapeutic targets. Our data revealed the expression and potential regulatory factors of HDAC1 in LUAD of data mining, which laid a foundation for the study of the occurrence, development, and treatment of HDAC1 in LUAD.

Berbamine dihydrochloride suppresses the progression of colorectal cancer via RTKs/Akt axis

Ethnopharmacological relevanceBerberis amurensis Rupr. is used to treat cancer as a traditional herbal medicine. Berbamine (BBM) is a natural bisbenzylisoquinoline alkaloid extracted from Berberis amurensis which possesses multiple pharmacological activity including anticancer. Aim of the studyTo investigate the influence of BBM on the progression of colorectal cancer (CRC) and further explore the underlying mechanism of BBM based on the RTKs/Akt signaling pathway. Materials and methodsIn vitro, cell viability and colony formation were conducted to detect BBM inhibitory of CRC cell lines. Transwell was detected the ability of migration and invasion by BBM. Apoptosis detection assay, cell cycle assay and the measurement of ROS were detected to confirm the inductive effect of cell apoptosis. RT-qPCR and Western blot to clarify the specific mechanism of anticancer. Finally, we conducted HE staining, Ki67, Tunnel and immunochemistry were confirmed the anti-colorectal cancer activity of BBM from vivo study. ResultsWe found that BBM could inhibit CRC cell lines growth. Moreover, BBM presented an inhibitory effect the ability of migration and invasion in CRC cells. Furthermore, the occurrence of apoptosis was involved in the anti-colorectal cancer role of BBM. BBM also triggered ROS accumulation in CRC cells that might be a key factor for the inductive effect of BBM in cell apoptosis. Cell cycle assay revealed that BBM induced the arrest of G1-S phase and increased the p21 levels but decreased CyclinE1, CyclinE2, CDK6, CyclinD1. RT-qPCR manifested that the down-regulation effect of BBM on AKT1, EGFR, PDGFRα and FGFR4 genes. The results also showed that BBM could decreased the expression levels of phosphor-AKT, PDGFRα, PDGFRβ, EGFR, FGFR3 and FGFR4 which belong to RTKs family. Consistently, BBM remarkably suppressed tumor xenograft growth in nude mice. ConclusionTaken together, all the results as presented above suggest that BBM as a novel multitargeted receptor tyrosine kinase inhibitor plays a crucial role in the inhibitory effect of CRC and may be a promising therapeutic agent for the CRC in clinic.

Loss of transcription factor EB dysregulates the G1/S transition and DNA replication in mammary epithelial cells

Triple-negative breast cancer (TNBC) poses significant challenges for treatment given the lack of targeted therapies and increased probability of relapse. It is pertinent to identify vulnerabilities in TNBC and develop newer treatments. Our prior research demonstrated that transcription factor EB (TFEB) is necessary for TNBC survival by regulating DNA repair, apoptosis signaling, and the cell cycle. However, specific mechanisms by which TFEB targets DNA repair and cell cycle pathways are unclear, and whether these effects dictate TNBC survival is yet to be determined. Here, we show that TFEB knockdown decreased the expression of genes and proteins involved in DNA replication and cell cycle progression in MDA-MB-231 TNBC cells. DNA replication was decreased in cells lacking TFEB, as measured by EdU incorporation. TFEB silencing in MDA-MB-231 and noncancerous MCF10A cells impaired progression through the S-phase following G1/S synchronization; however, this proliferation defect could not be rescued by co-knockdown of suppressor RB1. Instead, TFEB knockdown reduced origin licensing in G1 and early S-phase MDA-MB-231cells. TFEB silencing was associated with replication stress in MCF10A but not in TNBC cells. Lastly, we identified that TFEB knockdown renders TNBC cells more sensitive to inhibitors of Aurora Kinase A, a protein facilitating mitosis. Thus, inhibition of TFEB impairs cell cycle progress by decreasing origin licensing, leading to delayed entry into the S-phase, while rendering TNBC cells sensitive to Aurora kinase A inhibitors and decreasing cell viability. In contrast, TFEB silencing in noncancerous cells is associated with replication stress and leads to G1/S arrest.

Expression and Significance of Cyclin-Dependent Protein Kinase 6 in Diffuse Large B-Cell Lymphoma.

ObjectiveTo study the relationship between cyclin-dependent protein kinase 6 (CDK6) expression in diffuse large B-cell lymphoma (DLBCL) and the clinical biological behavior and prognosis.MethodsData mining was performed using the Oncomine and The Cancer Genome Atlas (TCGA) databases to analyze the expression level of CDK6 in DLBCL. CDK6 alterations in DLBCL and related functional networks were analyzed with c-BioPortal and the Gene Set Enrichment Analysis was performed by using DAVID and FunRich software. In addition, screening for differential gene expression of CDK6 was done and enriched by using LinkedOmics. Finally, formalin-fixed and paraffin-embedded (FFPE) tissue samples from 102 patients with DLBCL were collected from the Department of Pathology, Shanxi Cancer Hospital (Taiyuan, Shanxi, China) from January 2015 through December 2020. All cases had complete clinical course records. Thirty cases of lymph node reactive hyperplasia tissues were used as controls. The expression of CDK6 in DLBCL tissues was detected by qRT‑PCR and immunohistochemistry.ResultsBioinformatics analysis: The data showed that mRNA expression level and DNA copy number variations (CNVs) of CDK6 were significantly higher in DLBCL as compared to normal tissue (P ˂ 0.05). Based on C-BioPortal analysis, we speculated that amplification was the most common copy of CDK6 CNV in DLBCL. Through Gene Ontology (GO) analysis of these genes, it was found that the proteins were mainly located in the nucleus and cytoplasm. The biological interaction network of CDK6 alterations were found to participate primarily in the G1-S phase of the process. Analysis of LinkedOmics mRNA sequencing data showed that three genes were positively correlated with CDK6 expression: PSMD1, C2orf29 and ASB1. Through experimental verification, we found that CDK6 was overexpressed in DLBCL, and the expression of CDK6 mRNA and protein in DLBCL were positively correlated with Ann Arbor staging and IPI score (P<0.05), and negatively correlated with overall survival (P<0.001).ConclusionData mining results and experiments revealed and confirmed multi-level evidence for the importance of CDK6 in DLBCL; hence, CDK6 may be a potential marker in DLBCL. Thus, our study will perhaps lay the foundation for further research on the role of CDK6 in the genesis and development of DLBCL.

Anoctamin 5 regulates the cell cycle and affects prognosis in gastric cancer.

BACKGROUNDAnoctamin 5 (ANO5)/transmembrane protein 16E belongs to the ANO/ transmembrane protein 16 anion channel family. ANOs comprise a family of plasma membrane proteins that mediate ion transport and phospholipid scrambling and regulate other membrane proteins in numerous cell types. Previous studies have elucidated the roles and mechanisms of ANO5 activation in various cancer types. However, it remains unclear whether ANO5 acts as a plasma membrane chloride channel, and its expression and functions in gastric cancer (GC) have not been investigated. AIMTo examine the role of ANO5 in the regulation of tumor progression and clinicopathological significance of its expression in GC.METHODSKnockdown experiments using ANO5 small interfering RNA were conducted in human GC cell lines, and changes in cell proliferation, cell cycle progression, apoptosis, and cellular movement were assessed. The gene expression profiles of GC cells were investigated following ANO5 silencing by microarray analysis. Immunohistochemical staining of ANO5 was performed on 195 primary tumor samples obtained from patients with GC who underwent curative gastrectomy between 2011 and 2013 at our department.RESULTSReverse transcription-quantitative polymerase chain reaction (PCR) and western blotting demonstrated high ANO5 mRNA and protein expression, respectively, in NUGC4 and MKN45 cells. In these cells, ANO5 silencing inhibited cell proliferation and induced apoptosis. In addition, the knockdown of ANO5 inhibited G1-S phase progression, invasion, and migration. The results of the microarray analysis revealed changes in the expression levels of several cyclin-associated genes, such as CDKN1A, CDK2/4/6, CCNE2, and E2F1, in ANO5-depleted NUGC4 cells. The expression of these genes was verified using reverse transcription-quantitative PCR. Immunohistochemical staining revealed that high ANO5 expression levels were associated with a poor prognosis. Multivariate analysis identified high ANO5 expression as an independent prognostic factor for 5-year survival in patients with GC (P = 0.0457).CONCLUSIONANO5 regulates the cell cycle progression by regulating the expression of cyclin-associated genes and affects the prognosis of patients with GC. These results may provide insights into the role of ANO5 as a key mediator in tumor progression and/or promising prognostic biomarker for GC.

Both phosphorylation and phosphatase activity of PTEN are required to prevent replication fork progression during stress by inducing heterochromatin

PTEN is a tumor suppressor protein frequently altered in various cancers. PTEN-null cells have a characteristic of rapid proliferation with an unstable genome. Replication stress is one of the causes of the accumulation of genomic instability if not sensed by the cellular signaling. Though PTEN-null cells have shown to be impaired in replication progression and stalled fork recovery, the association between the catalytic function of PTEN regulated by posttranslational modulation and cellular response to replication stress has not been studied explicitly. To understand molecular mechanism, we find that PTEN-null cells display unrestrained replication fork progression with accumulation of damaged DNA after treatment with aphidicolin which can be rescued by ectopic expression of full-length PTEN, as evident from DNA fiber assay. Moreover, the C-terminal phosphorylation (Ser 380, Thr 382/383) of PTEN is essential for its chromatin association and sensing replication stress that, in response, induce cell cycle arrest. Further, we observed that PTEN induces HP1α expression and H3K9me3 foci formation in a C-terminal phosphorylation-dependent manner. However, phosphatase dead PTEN cannot sense replication stress though it can be associated with chromatin. Together, our results suggest that DNA replication perturbation by aphidicolin enables chromatin association of PTEN through C-terminal phosphorylation, induces heterochromatin formation by stabilizing and up-regulating H3K9me3 foci and augments CHK1 activation. Thereby, PTEN prevents DNA replication fork elongation and simultaneously causes G1-S phase cell cycle arrest to limit cell proliferation in stress conditions. Thus PTEN act as stress sensing protein during replication arrest to maintain genomic stability.

The Combination of the CDK4/6 Inhibitor, Palbociclib, With the Vitamin D3 Analog, Inecalcitol, Has Potent In Vitro and In Vivo Anticancer Effects in Hormone-Sensitive Breast Cancer, But Has a More Limited Effect in Triple-Negative Breast Cancer.

Active vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], and its synthetically derived analogs possess potent anticancer properties. In breast cancer (BC) cells, 1,25(OH)2D3 blocks cell proliferation and induces apoptosis through different cell-type specific mechanisms. In this study, we evaluated if the combination of the potent vitamin D3 analog, inecalcitol, with a selective CDK4/6 inhibitor, palbociclib, enhanced the antiproliferative effects of both single compounds in hormone-sensitive (ER+) BC, for which palbociclib treatment is already approved, but also in triple-negative BC (TNBC). Inecalcitol and palbociclib combination treatment decreased cell proliferation in both ER+ (T47D-MCF7) and TNBC (BT20-HCC1143-Hs578T) cells, with a more pronounced antiproliferative effect in the former. In ER+ BC cells, the combination therapy downregulated cell cycle regulatory proteins (p)-Rb and (p)-CDK2 and blocked G1-S phase transition of the cell cycle. Combination treatment upregulated p-mTOR and p-4E-BP1 protein expression in MCF7 cells, whereas it suppressed expression of these proteins in BT20 cells. Cell survival was decreased after inecalcitol treatment either alone or combined in MCF7 cells. Interestingly, the combination therapy upregulated mitochondrial ROS and mitotracker staining in both cell lines. Furthermore, in vivo validation in a MCF7 cell line-derived xenograft mouse model decreased tumor growth and cell cycle progression after combination therapy, but not in a TNBC BT20 cell line-derived xenograft model. In conclusion, we show that addition of a potent vitamin D3 analog to selective CDK4/6 inhibitor treatment results in increased antiproliferative effects in ER+ BC both in vitro and in vivo.

FOXM1 Promotes Malignant Proliferation of Esophageal Squamous Cell Carcinoma Through Transcriptional Activating CDC6.

Forkhead box M1 (FOXM1) is a proliferative transcription factor and plays a vital role in many cancers. However, the function and molecular mechanism of FOXM1 in esophageal squamous cell carcinoma (ESCC) remain poorly understood. Hence, we aim to clarify the molecular basis of FOXM1-mediated ESCC progression. In this study, bioinformatics analysis showed that FOXM1 was mainly involved in key signal pathways, including cell proliferation, cell cycle, and homologous recombination in ESCC, and predicted that CDC6 might be a potential regulatory target gene of FOXM1. The results revealed that FOXM1 and CDC6 were significantly overexpressed in ESCC tissue and cell line, and their expression was positively correlated. Further studies showed that FOXM1 directly transcriptionally activated CDC6 by binding to its promoter region in ESCC cells. Moreover, FOXM1 mediated ESCC cell proliferation by regulating CDC6 expression, which may be related to promoting G1-S phase transition of cell cycle. Taken together, FOXM1-CDC6 axis mediates ESCC malignant proliferation and may serve as a potential biological target for ESCC treatment.

AZFa Y gene, DDX3Y, evolved novel testis transcript variants in primates with proximal 3´UTR polyadenylation for germ cell specific translation

Translational control is a major level of gene expression regulation in the male germ line. DDX3Y located in the AZFa region of the human Y chromosome encodes a conserved RNA helicase important for translational control at the G1-S phase of the cell cycle. In human, DDX3Y protein is expressed only in premeiotic male germ cells. In primates, DDX3Y evolved a second promoter producing novel testis-specific transcripts. Here, we show primate species-specific use of alternative polyadenylation (APA) sites for these testis-specific DDX3Y transcript variants. They have evolved subsequently in the 3´UTRs of the primates´ DDX3Y transcripts. Whereas a distal APA site (PAS4) is still used for polyadenylation of most DDX3Y testis transcripts in Callithrix jacchus; two proximal APAs (PAS1; PAS2) are used predominantly in Macaca mulatta, in Pan trogloydates and in human. This shift corresponds with a significant increase of DDX3Y protein expression in the macaque testis tissue. In chimpanzee and human, shift to predominant use of the most proximal APA site (PAS1) is associated with translation of these DDX3Y transcripts in only premeiotic male germ cells. We therefore assume evolution of a positive selection process for functional DDX3Y testis transcripts in these primates which increase their stability and translation efficiency to promote its cell cycle balancing function in the human male germ line.

Annexin A2: The diversity of pathological effects in tumorigenesis and immune response

Annexin A2 (ANXA2) is widely used as a marker in a variety of tumors. By regulating multiple signal pathways, ANXA2 promotes the epithelial-mesenchymal transition, which can cause tumorigenesis and accelerate thymus degeneration. The elevated ANXA2 heterotetramer facilitates the production of plasmin, which participates in pathophysiologic processes such as tumor cell invasion and metastasis, bleeding diseases, angiogenesis, inducing the expression of inflammatory factors. In addition, the ANXA2 on the cell membrane mediates immune response via its interaction with surface proteins of pathogens, C1q, toll-like receptor 2, anti-dsDNA antibodies and immunoglobulins. Nuclear ANXA2 plays a role as part of a primer recognition protein complex that enhances DNA synthesis and cells proliferation by acting on the G1-S phase of the cell. ANXA2 reduction leads to the inhibition of invasion and metastasis in multiple tumor cells, bleeding complications in acute promyelocytic leukemia, retinal angiogenesis, autoimmunity response and tumor drug resistance. In this review, we provide an update on the pathological effects of ANXA2 in both tumorigenesis and the immune response. We highlight ANXA2 as a critical protein in numerous malignancies and the immune host response.

Design, synthesis and antitumor evaluation of novel 1H-indole-2-carboxylic acid derivatives targeting 14-3-3η protein

In this work, a series of novel 1H-indole-2-carboxylic acid derivatives targeting 14-3-3η protein were designed and synthesized for treatment of liver cancer. After structural optimization for several rounds, C11 displayed a relatively better affinity with 14-3-3η, as well as the best inhibitory activities against several typical human liver cancer cell lines, including Bel-7402, SMMC-7721, SNU-387, Hep G2 and Hep 3B cells. Compound C11 also displayed best inhibitory activity against chemotherapy-resistant Bel-7402/5-Fu cells. Besides, C11 was rather safe against hERG and possessed moderate T1/2 and CL values in liver microsomes. In anti-proliferation, trans-well and cell apoptosis assays, C11 also showed its huge potential as a potent antitumor agent. Then, Western blot assay was conducted, following analyzed by molecular docking, the anti-proliferative mechanisms of this small-molecule inhibitor were revealed. Moreover, C11 was demonstrated to induce G1-S phase cell cycle arrest in liver cancer cells.

Inheritance of repressed chromatin domains during S phase requires the histone chaperone NPM1.

The epigenetic process safeguards cell identity during cell division through the inheritance of appropriate gene expression profiles. We demonstrated previously that parental nucleosomes are inherited by the same chromatin domains during DNA replication only in the case of repressed chromatin. We now show that this specificity is conveyed by NPM1, a histone H3/H4 chaperone. Proteomic analyses of late S-phase chromatin revealed NPM1 in association with both H3K27me3, an integral component of facultative heterochromatin, and MCM2, an integral component of the DNA replication machinery; moreover, NPM1 interacts directly with PRC2 and with MCM2. Given that NPM1 is essential, the inheritance of repressed chromatin domains was examined anew using mESCs expressing an auxin-degradable version of endogenous NPM1. Upon NPM1 degradation, cells accumulated in the G1-S phase of the cell cycle and parental nucleosome inheritance from repressed chromatin domains was markedly compromised. NPM1 chaperone activity may contribute to the integrity of this process as appropriate inheritance required the NPM1 acidic patches.

Co-expression patterns explain how a basic transcriptional role for MYC modulates Wnt and MAPK pathways in colon and lung adenocarcinomas

ABSTRACT A subset of proliferation genes that are associated with origin licensing, firing, and DNA synthesis has been compared to known drivers of colon (COAD) and lung (LUAD) adenocarcinomas using Spearman’s rank correlation coefficients. The frequency with which APC, CTNNB1, KRAS, MYC, Braf, TP53, Rb1, EGFR, and cell cycle components have direct or indirect co-expression with the proliferation factors permits identification of their expression relative to the G1-S phase of the cell cycle. Here, adenomatous polyposis coli (APC), a negative regulator of Wnt signaling known to function through MYC, indirectly co-expresses at the same frequency as proliferation genes in both COAD and LUAD, consistent with M phase expression. However, APC is indirectly co-expressed with MYC and is found mutated only in COAD. MYC is thought to function at the interface of transcription and replication, acting through the SWI/SNF chromatin remodeling complex, and increased or decreased expression of MYC can induce or repress tumorigenesis, respectively. These data suggest that transcription of APC during the M phase with low MYC co-expression contributes by an unknown mechanism to APC mutations and Wnt pathway deregulation in COAD and that upper and lower limits of MYC expression, enforced by the cell cycle, may influence cancer differentially. Other Wnt signaling components co-expressed in the low MYC context in COAD also have significantly higher mutation frequencies, supporting the hypothesis. Additionally, Braf is found here to have direct co-expression with multiple proliferation factors in non-EGFR activated LUAD, and EGFR-activated LUAD are completely deregulated with respect to E2F(s) 4/5/6 expression, potentially explaining the low proliferation rates seen in LUAD. Abbreviations: TCGA: The cancer genome atlas; PANCAN: Pan cancer; CDK: Cyclin-dependent kinase; COAD: Colon adenocarcinoma; LUAD: Lung adenocarcinoma; Wnt: Wingless/integrated signaling; MAPK: Mitogen-activated protein kinase; APC: Adenomatous polyposis coli gene; CIN: Chromosomal instability; GS: Genome stabile; MMR: Mismatch repair; mRNA: Messenger RNA; RPKM: Reads per kilobase of transcription per million mapped reads; RSEM: RNA Seq by expectation maximization; FDR: False discovery rate; GTEx: Genotype-Tissue Expression portal; MPF: Maturation-promoting factor; SCF: Skp1-Cul1-F-box; HH: Hedgehog; EMT: Epithelial mesenchymal transition; RB: Retinoblastoma; EGFR: Epidermal growth factor receptor; rs or ρ: Spearman’s correlation