Expression Of Cell Cycle-related Genes Research Articles

Nitric oxide is involved in hydrogen gas-induced cell cycle activation during adventitious root formation in cucumber.

BackgroundAdventitious root development is a complex process regulated through a variety of signaling molecules. Hydrogen gas (H2) and nitric oxide (NO), two new signaling molecules are both involved in plant development and stress tolerance.ResultsTo investigate the mechanism of adventitious root development induced by hydrogen-rich water (HRW), a combination of fluorescence microscopy and molecular approaches was used to study cell cycle activation and cell cycle-related gene expression in cucumber (Cucumis sativus ‘Xinchun 4’) explants. The results revealed that the effect of HRW on adventitious root development was dose-dependent, with maximal biological responses at 50 % HRW. HRW treatment increased NO content in a time-dependent fashion. The results also indicated that HRW and NO promoted the G1-to-S transition and up-regulated cell cycle-related genes: CycA (A-type cyclin), CycB (B-type cyclin), CDKA (cyclin-dependent kinase A) and CDKB (cyclin-dependent kinase B) expression. Additionally, target genes related to adventitious rooting were up-regulated by HRW and NO in cucumber explants. While, the responses of HRW-induced adventitious root development and increase of NO content were partially blocked by a specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt, NO synthase (NOS)-like enzyme inhibitor NG –nitro-L-arginine methylester hydrochloride, or nitrate reductase inhibitors tungstate and NaN3. These chemicals also partially reversed the effect of HRW on cell cycle activation and the transcripts of cell cycle regulatory genes and target genes related adventitious root formation.ConclusionsTogether, NO may emerge as a downstream signaling molecule in H2-induced adventitious root organogenesis. Additionally, H2 mediated cell cycle activation via NO pathway during adventitious root formation.

Ghrelin regulates cell cycle-related gene expression in cultured hippocampal neural stem cells.

We have previously demonstrated that ghrelin stimulates the cellular proliferation of cultured adult rat hippocampal neural stem cells (NSCs). However, little is known about the molecular mechanisms by which ghrelin regulates cell cycle progression. The purpose of this study was to investigate the potential effects of ghrelin on cell cycle regulatory molecules in cultured hippocampal NSCs. Ghrelin treatment increased proliferation assessed by CCK-8 proliferation assay. The expression levels of proliferating cell nuclear antigen and cell division control 2, well-known cell-proliferating markers, were also increased by ghrelin. Fluorescence-activated cell sorting analysis revealed that ghrelin promoted progression of cell cycle from G0/G1 to S phase, whereas this progression was attenuated by the pretreatment with specific inhibitors of MEK/extracellular signal-regulated kinase 1/2, phosphoinositide 3-kinase/Akt, mammalian target of rapamycin, and janus kinase 2/signal transducer and activator of transcription 3. Ghrelin-induced proliferative effect was associated with increased expression of E2F1 transcription factor in the nucleus, as determined by Western blotting and immunofluorescence. We also found that ghrelin caused an increase in protein levels of positive regulators of cell cycle, such as cyclin A and cyclin-dependent kinase (CDK) 2. Moreover, p27(KIP1) and p57(KIP2) protein levels were reduced when cell were exposed to ghrelin, suggesting downregulation of CDK inhibitors may contribute to proliferative effect of ghrelin. Our data suggest that ghrelin targets both cell cycle positive and negative regulators to stimulate proliferation of cultured hippocampal NSCs.

Trichoderma harzianum-induced resistance against Fusarium oxysporum involves regulation of nuclear DNA content, cell viability and cell cycle-related genes expression in cucumber roots

Fusarium wilt, one of the destructive diseases of cucumber can be effectively controlled by using biocontrol agents such as Trichoderma harzianum. However, the mechanisms controlling T. harzianum-induced enhanced resistance remain largely unknown in cucumber plants. Here we screened the potent T. harzianum isolate TH58 that could effectively control F. oxysporum (FO). Glasshouse efficacy trials also showed that TH58 decreased disease incidence by 69.7 %. FO induced ROS over accumulation, while TH58 inoculation suppressed ROS over accumulation and improved root cell viability under F. oxysporum infection. TH58 inoculation could reverse the FO-induced cell division block and regulate the proportional distribution of nuclear DNA content through inducing 2C fraction. Moreover, the expression levels of cell cycle-related genes such as CDKA, CDKB, CycA, CycB, CycD3;1 and CycD3;2 in TH58 - pre-inoculated seedlings were up-regulated compared with those infected with FO alone. Taken together, these results suggest that T. harzianum improved plant resistance against Fusarium wilt disease via alterations in nuclear DNA content and cell cycle-related genes expression that might maintain a lower ROS accumulation and higher root cell viability in cucumber seedlings.

The cell cycle-related genes as biomarkers for schizophrenia

BackgroundRecent studies suggest that genomic abnormalities such as single nucleotide polymorphisms (SNPs) and copy number variations (CNVs) may elevate the risk of schizophrenia. Such genomic abnormalities often occur during chromosomal DNA replication in the S phase of cell cycle. In addition, several studies showed that abnormal expressions of several cell cycle-related genes are associated with schizophrenia. Therefore, here we compared mRNA expression levels of cell cycle-related genes in peripheral blood cells between patients with schizophrenia and healthy controls. MethodmRNA expression levels of cell cycle-related genes in peripheral blood cells from patients with schizophrenia and healthy controls were measured with quantitative reverse transcription polymerase chain reaction (Q-RT-PCR). The discovery, replication and intervention studies with Q-RT-PCR were performed as follows: discovery (40 cases and 20 controls), replication (82 cases and 74 controls) and intervention (22 cases and 18 controls). ResultNine genes were identified in the discovery and replication stages as schizophrenia-associated genes. Moreover, the combination of mRNA expression levels of CDK4, MCM7 and POLD4 was identified as a potential biomarker for schizophrenia with multivariate logistic regression analysis. The intervention stage revealed that the mRNA expression levels of these three genes were significantly decreased in the acute state of schizophrenia, and CDK4 was significantly recovered in the remission state of schizophrenia. ConclusionThe combination of mRNA expression levels of three cell cycle-related genes such as CDK4, MCM7 and POLD4 is expected to be a candidate for useful biomarkers for schizophrenia. Especially, the mRNA expression changes of CDK4 may be potential as both trait and state markers for schizophrenia.

Attenuation of Postischemic Genomic Alteration by Mesenchymal Stem Cells: a Microarray Study.

Intravenous administration of mesenchymal stem cells (IV-MSC) protects the ischemic rat brain in a stroke model, but the molecular mechanism underlying its therapeutic effect is unclear. We compared genomic profiles using the mRNA microarray technique in a rodent stroke model. Rats were treated with 1 × 106 IV-MSC or saline (sham group) 2 h after transient middle cerebral artery occlusion (MCAo). mRNA microarray was conducted 72 h after MCAo using brain tissue from normal rats (normal group) and the sham and MSC groups. Predicted pathway analysis was performed in differentially expressed genes (DEGs), and functional tests and immunohistochemistry for inflammation-related proteins were performed. We identified 857 DEGs between the sham and normal groups, with the majority of them (88.7%) upregulated in sham group. Predicted pathway analysis revealed that cerebral ischemia activated 10 signaling pathways mainly related to inflammation and cell cycle. IV-MSC attenuated the numbers of dysregulated genes in cerebral ischemia (118 DEGs between the MSC and normal groups). In addition, a total of 218 transcripts were differentially expressed between the MSC and sham groups, and most of them (175/218 DEGs, 80.2%) were downregulated in the MSC group. IV-MSC reduced the number of Iba-1+ cells in the peri-infarct area, reduced the overall infarct size, and improved functional deficits in MCAo rats. In conclusion, transcriptome analysis revealed that IV-MSC attenuated postischemic genomic alterations in the ischemic brain. Amelioration of dysregulated inflammation- and cell cycle-related gene expression in the host brain is one of the molecular mechanisms of IV-MSC therapy for cerebral ischemia.

Investigation of Transcriptional Gene Profiling in Normal Murine Hair Follicular Substructures Using Next-Generation Sequencing to Provide Potential Insights Into Skin Disease.

Skin diseases, including hair-related diseases and neoplasia, are a major public health problem. While their prevalence is increasing, their treatment options are limited. Researchers have tried to investigate the genes and signal pathways underlying hair follicles (HFs) to develop genetically targeted therapies through microarrays, which represent an appropriate modality for the analysis of small genomes. To enable the comprehensive transcriptome analysis of large and/or complex transcriptomes, we performed RNA-seq using next-generation sequencing (NGS). We isolated interfollicular keratinocytes (IFKs), HFs, and dermal fibroblasts including dermal papilla cells (DFs-DPCs) from normal C57BL/6 murine skin, transplanted combinations of these samples into nude mice, and followed the mice over time. Sustained hair growth was supported by HFs and DFs-DPCs. We then investigated the pathways and the relevant gene ontology associated with any identified differentially expressed genes (DEGs). In addition, in the culture and flow cytometry (FCM), the HFs had a more quiescent cell cycle pattern than did the IFKs and DFs-DPCs. Therefore, the representative cell cycle-related gene expression of IFKs, HFs, and DFs-DPCs was analyzed by NGS. Our study will allow researchers to further investigate the potential interactions and signaling pathways that are active in HF-related diseases and cancer and may aid in future bioengineering applications.

YAP and ERK mediated mechanical strain-induced cell cycle progression through RhoA and cytoskeletal dynamics in rat growth plate chondrocytes.

Yes-associated protein (YAP) and extracellular signal-regulated kinase (ERK) have been considered as key regulators in tissue homeostasis, organ development, and tumor formation. However, the roles of YAP and ERK in the mediating strain mechanosensing in the growth plate cartilage have not been determined. In this study, chondrocytes obtained from the growth plate cartilage of 2-week-old Sprague-Dawley rats were subjected to the mechanical strain with different magnitudes and durations at a frequency of 0.5 Hz. We found that YAP and ERK activation in response to mechanical strain was time and magnitude dependent. Pretreatment with a RhoA inhibitor (C3 toxin) or a microfilament cytoskeleton disrupting reagent (cytochalasin D) could suppress their activation. In addition, activated YAP and ERK were able to induce cell cycle progression by up-regulating the expression of cell cycle-related genes. These results shed new light on the function of YAP and ERK in mechanical strain-promoted growth plate development. Our results also provided evidence that RhoA and cytoskeletal dynamics are required for this mechanotransduction. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1121-1129, 2016.

Pediatric Ependymoma: Molecular Characteristics and Useful Prognostic Markers

Ependymoma is a type of brain tumor that originates from ependymal cells in the ventricular system of the brain and the central canal of the spinal cord. Ependymoma tumors remain a public health concern. Over the last several decades, ependymoma tumors have been studied at the molecular level. In pediatric ependymomas, deletions of chromosomes 6q and 22q as well as the amplification of chromosome 1q have been observed. The MMP2, MMP14, PI3K, and MGMT genes have been proposed to be prognostic markers of ependymoma. At the epigenetic level, medullary ependymoma has a different methylation pattern from intracranial EP. The EZH2 and MGMT genes play an important role in cell cycle-related gene expression.

Mitochondrial regulation of cell cycle progression through SLC25A43

An increasing body of evidence is pointing towards mitochondrial regulation of the cell cycle. In a previous study of HER2-positive tumours we could demonstrate a common loss in the gene encoding for the mitochondrial transporter SLC25A43 and also a significant relation between SLC25A43 protein expression and S-phase fraction. Here, we investigated the consequence of suppressed SLC25A43 expression on cell cycle progression and proliferation in breast epithelial cells.In the present study, we suppressed SLC25A43 using siRNA in immortalised non-cancerous breast epithelial MCF10A cells and HER2-positive breast cancer cells BT-474. Viability, apoptosis, cell proliferation rate, cell cycle phase distribution, and nuclear Ki-67 and p21, were assessed by flow cytometry. Cell cycle related gene expressions were analysed using real-time PCR.We found that SLC25A43 knockdown in MCF10A cells significantly inhibited cell cycle progression during G1-to-S transition, thus significantly reducing the proliferation rate and fraction of Ki-67 positive MCF10A cells. In contrast, suppressed SLC25A43 expression in BT-474 cells resulted in a significantly increased proliferation rate together with an enhanced G1-to-S transition. This was reflected by an increased fraction of Ki-67 positive cells and reduced level of nuclear p21. In line with our previous results, we show a role for SLC25A43 as a regulator of cell cycle progression and proliferation through a putative mitochondrial checkpoint. These novel data further strengthen the connection between mitochondrial function and the cell cycle, both in non-malignant and in cancer cells.

Different Donor Cell Culture Methods Can Influence the Developmental Ability of Cloned Sheep Embryos.

It was proposed that arresting nuclear donor cells in G0/G1 phase facilitates the development of embryos that are derived from somatic cell nuclear transfer (SCNT). Full confluency or serum starvation is commonly used to arrest in vitro cultured somatic cells in G0/G1 phase. However, it is controversial as to whether these two methods have the same efficiency in arresting somatic cells in G0/G1 phase. Moreover, it is unclear whether the cloned embryos have comparable developmental ability after somatic cells are subjected to one of these methods and then used as nuclear donors in SCNT. In the present study, in vitro cultured sheep skin fibroblasts were divided into four groups: (1) cultured to 70–80% confluency (control group), (2) cultured to full confluency, (3) starved in low serum medium for 4 d, or (4) cultured to full confluency and then further starved for 4 d. Flow cytometry was used to assay the percentage of fibroblasts in G0/G1 phase, and cell counting was used to assay the viability of the fibroblasts. Then, real-time reverse transcription PCR was used to determine the levels of expression of several cell cycle-related genes. Subsequently, the four groups of fibroblasts were separately used as nuclear donors in SCNT, and the developmental ability and the quality of the cloned embryos were compared. The results showed that the percentage of fibroblasts in G0/G1 phase, the viability of fibroblasts, and the expression levels of cell cycle-related genes was different among the four groups of fibroblasts. Moreover, the quality of the cloned embryos was comparable after these four groups of fibroblasts were separately used as nuclear donors in SCNT. However, cloned embryos derived from fibroblasts that were cultured to full confluency combined with serum starvation had the highest developmental ability. The results of the present study indicate that there are synergistic effects of full confluency and serum starvation on arresting fibroblasts in G0/G1 phase, and the short-term treatment of nuclear donor cells with these two methods could improve the efficiency of SCNT.

Differential expression and alternative splicing of cell cycle genes in imatinib-treated K562 cells.

Cancer progression often involves the disorder of the cell cycle, and a number of effective chemotherapeutic drugs have been shown to induce cell cycle arrest. The purpose of this study was to comprehensively investigate the effects of imatinib on the expression profile of cell cycle genes in the chronic myeloid leukemia (CML) K562 cell line. In addition, we also investigated alternative splicing of the cell cycle genes affected by imatinib, since an important relationship has been shown to exist between RNA splicing and cell cycle progression. Exon array analysis was performed using total RNA purified from normal and imatinib-treated K562 cells. We identified 185 differentially expressed genes and 277 alternative splicing events between the two cell groups. A detailed analysis by reverse transcription-PCR (RT-PCR) of key genes confirmed the experimental results of the exon array. These results suggested that treatment of K562 cells with imatinib shifts the expression and alternative splicing profiles of several cell cycle-related genes. Importantly, these findings may help improve imatinib treatment strategies in patients with CML and may be useful for imatinib resistance research and CML drug development.

Gankyrin drives malignant transformation of chronic liver damage-mediated fibrosis via the Rac1/JNK pathway

Hepatocarcinogenesis is a complex process involving chronic liver injury, inflammation, unregulated wound healing, subsequent fibrosis and carcinogenesis. To decipher the molecular mechanism underlying transition from chronic liver injury to dysplasia, we investigated the oncogenic role of gankyrin (PSMD10 or p28GANK) during malignant transformation in a transgenic mouse model. Here, we find that gankyrin increased in patients with cirrhosis. In addition to more severe liver fibrosis and tumorigenesis after DEN plus CCl4 treatment, hepatocyte-specific gankyrin-overexpressing mice (gankyrinhep) exhibited malignant transformation from liver fibrosis to tumors even under single CCl4 administration, whereas wild-type mice merely experienced fibrosis. Consistently, enhanced hepatic injury, severe inflammation and strengthened compensatory proliferation occurred in gankyrinhep mice during CCl4 performance. This correlated with augmented expressions of cell cycle-related genes and abnormal activation of Rac1/c-jun N-terminal kinase (JNK). Pharmacological inhibition of the Rac1/JNK pathway attenuated hepatic fibrosis and prevented CCl4-induced carcinogenesis in gankyrinhep mice. Together, these findings suggest that gankyrin promotes liver fibrosis/cirrhosis progression into hepatocarcinoma relying on a persistent liver injury and inflammatory microenvironment. Blockade of Rac1/JNK activation impeded gankyrin-mediated hepatocytic malignant transformation, indicating the combined inhibition of gankyrin and Rac1/JNK as a potential prevention mechanism for cirrhosis transition.

A novel derivative of betulinic acid, SYK023, suppresses lung cancer growth and malignancy.

Herein, we evaluated the anti-cancer effect and molecular mechanisms of a novel betulinic acid (BA) derivative, SYK023, by using two mouse models of lung cancer driven by KrasG12D or EGFRL858R. We found that SYK023 inhibits lung tumor proliferation, without side effects in vivo or cytotoxicity in primary lung cells in vitro. SYK023 triggered endoplasmic reticulum (ER) stress. Blockage of ER stress in SYK023-treated cells inhibited SYK023-induced apoptosis. In addition, we found that the expression of cell cycle-related genes, including cyclin A2, B1, D3, CDC25a, and CDC25b decreased but, while those of p15INK4b, p16INK4a, and p21CIP1 increased following SYK023 treatment. Finally, low doses of SYK023 significantly decreased lung cancer metastasis in vitro and in vivo. Expression of several genes related to cell migration, including synaptopodin, were downregulated by SYK023, thereby impairing F-actin polymerization and metastasis. Therefore, SYK023 may be a potentially therapeutic treatment for metastatic lung cancer.

Ectopic expression of a stress-inducible glycosyltransferase from saffron enhances salt and oxidative stress tolerance in Arabidopsis while alters anchor root formation

Glycosyltransferases play diverse roles in cellular metabolism by modifying the activities of regulatory metabolites. Three stress-regulated UDP-glucosyltransferase-encoding genes have been isolated from the stigmas of saffron, UGT85U1, UGT85U2 and UGT85V1, which belong to the UGT85 family that includes members associated with stress responses and cell cycle regulation. Arabidopsis constitutively expressing UGT85U1 exhibited and increased anchor root development. No differences were observed in the timing of root emergence, in leaf, stem and flower morphology or flowering time. However, salt and oxidative stress tolerance was enhanced in these plants. Levels of glycosylated compounds were measured in these plants and showed changes in the composition of several indole-derivatives. Moreover, auxin levels in the roots were higher compared to wild type. The expression of several key genes related to root development and auxin homeostasis, including CDKB2.1, CDKB2.2, PIN2, 3 and 4; TIR1, SHR, and CYCD6, were differentially regulated with an increase of expression level of SHR, CYCD6, CDKB2.1 and PIN2. The obtained results showed that UGT85U1 takes part in root growth regulation via auxin signal alteration and the modified expression of cell cycle-related genes, resulting in significantly improved survival during oxidative and salt stress treatments.

APOBEC3B expression in breast cancer reflects cellular proliferation, while a deletion polymorphism is associated with immune activation

Genomic sequencing studies of breast and other cancers have identified patterns of mutations that have been attributed to the endogenous mutator activity of APOBEC3B (A3B), a member of the AID/APOBEC family of cytidine deaminases. A3B gene expression is increased in many cancers, but its upstream drivers remain undefined. Furthermore, there exists a common germ-line deletion polymorphism (A3B(del)), which has been associated with a paradoxical increase in breast cancer risk. To examine causes and consequences of A3B expression and its constitutive absence in breast cancer, we analyzed two large clinically annotated genomic datasets [The Cancer Genome Atlas (TCGA) and the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC)]. We confirmed that A3B expression is associated with aggressive clinicopathologic characteristics and adverse outcomes and show that A3B expression is highly correlated with proliferative features (mitosis and cell cycle-related gene expression) in breast and 15 of 16 other solid tumor types. However, breast cancers arising in homozygous A3B(del) individuals with A3B absent did not differ in these features, indicating that A3B expression is a reflection rather than a direct cause of increased proliferation. Using gene set enrichment analysis (GSEA), we detected a pattern of immune activation in A3B(del) breast cancers, which seems to be related to hypermutation arising in A3B(del) carriers. Together, these results provide an explanation for A3B overexpression and its prognostic effect, giving context to additional study of this mutator as a cancer biomarker or putative drug target. In addition, although immune features of A3B(del) require additional study, these findings nominate the A3B(del) polymorphism as a potential predictor for cancer immunotherapy.

High-resolution genomic analysis does not qualify atypical plexus papilloma as a separate entity among choroid plexus tumors.

Choroid plexus tumors are rare neoplasms that mainly affect children. They include papillomas, atypical papillomas, and carcinomas. Detailed genetic studies are rare, and information about their molecular pathogenesis is limited. Molecular inversion probe analysis is a hybridization-based method that represents a reliable tool for the analysis of highly fragmented formalin-fixed paraffin-embedded tissue-derived DNA. Here, analysis of 62 cases showed frequent hyperdiploidy in papillomas and atypical papillomas that appeared very similar in their cytogenetic profiles. In contrast, carcinomas showed mainly losses of chromosomes. Besides recurrent focal chromosomal gains common to all choroid plexus tumors, including chromosome 14q21-q22 (harboring OTX2), chromosome 7q22 (LAMB1), and chromosome 9q21.12 (TRPM3), Genomic Identification of Significant Targets in Cancer analysis uncovered focal alterations specific for papillomas and atypical papillomas (e.g. 7p21.3 [ARL4A]) and for carcinomas (16p13.3 [RBFOX1] and 6p21 [POLH, GTPBP2, RSPH9, and VEGFA]). Additional RNA expression profiling and gene set enrichment analysis revealed greater expression of cell cycle-related genes in atypical papillomas in comparison with that in papillomas. These findings suggest that atypical papillomas represent an immature variant of papillomas characterized by increased proliferative activity, whereas carcinomas seem to represent a genetically distinct tumor group.

DC-SCRIPT is a novel regulator of the tumor suppressor gene CDKN2B and induces cell cycle arrest in ERα-positive breast cancer cells.

Breast cancer is one of the most common causes of cancer-related deaths in women. The estrogen receptor (ERα) is well known for having growth promoting effects in breast cancer. Recently, we have identified DC-SCRIPT (ZNF366) as a co-suppressor of ERα and as a strong and independent prognostic marker in ESR1 (ERα gene)-positive breast cancer patients. In this study, we further investigated the molecular mechanism on how DC-SCRIPT inhibits breast cancer cell growth. DC-SCRIPT mRNA levels from 190 primary ESR1-positive breast tumors were related to global gene expression, followed by gene ontology and pathway analysis. The effect of DC-SCRIPT on breast cancer cell growth and cell cycle arrest was investigated using novel DC-SCRIPT-inducible MCF7 breast cancer cell lines. Genome-wide expression profiling of DC-SCRIPT-expressing MCF7 cells was performed to investigate the effect of DC-SCRIPT on cell cycle-related gene expression. Findings were validated by real-time PCR in a cohort of 1,132 ESR1-positive breast cancer patients. In the primary ESR1-positive breast tumors, DC-SCRIPT expression negatively correlated with several cell cycle gene ontologies and pathways. DC-SCRIPT expression strongly reduced breast cancer cell growth in vitro, breast tumor growth in vivo, and induced cell cycle arrest. In addition, in the presence of DC-SCRIPT, multiple cell cycles related genes were differentially expressed including the tumor suppressor gene CDKN2B. Moreover, in 1,132 primary ESR1-positive breast tumors, DC-SCRIPT expression also correlated with CDKN2B expression. Collectively, these data show that DC-SCRIPT acts as a novel regulator of CDKN2B and induces cell cycle arrest in ESR1-positive breast cancer cells.Electronic supplementary materialThe online version of this article (doi:10.1007/s10549-015-3281-y) contains supplementary material, which is available to authorized users.

Evaluating the mRNA expression profile of APC in Pterygium

Introduction: The exact etiology of pterygium is unknown. Most of population based studies implicating that pterygium has a benign behavior rather than destructive condition. Changed expression of cell cycle-related genes may lead to the abnormal cell proliferation and finally to malignancy phenotype. The aim of this study was evaluation the expression profiles of APC in pterygium. Materials and Methods: The RNA extracted from the 23 pterygium tissues and 18 healthy tissues. After converting RNA to cDNA. The expression levels of these genes were assessed by real-time PCR. Results: The relative expression of APC gene in pterygium tissues was significantly different in comparison to conjunctiva tissues of healthy controls (mean ± SD was 1.82 ± 0.15 for cases versus 1.70  0.12 for controls, P value = 0.048). Conclusion: Detection of expression changes, leading to find molecular mechanism underlying the disease. As well as exploring pterygium markers paving the road for better therapy. We would like to propose further studies to identify exact molecular function of this gene in pterygium by using advanced molecular techniques such as RNAseq in various and larger genetic populations.

Attenuation of Leukemia/Lymphoma-Related Factor Protein Expression Inhibits Glioma Cell Proliferation and Invasion.

Overexpression of leukemia/lymphoma-related factor (LRF), which is an erythroid myeloid ontogenic factor protein, occurs in different cancers, including glioma. LRF is also reported to have an oncogenic activity in various human cancers. This study investigated the effect of LRF knockdown on the regulation of glioma growth. LRF short hairpin RNA (shRNA) suppressed the expression of LRF protein in a glioma cell line (GL261-EGFP) compared to the negative control vector-transfected glioma cells. LRF knockdown also reduced glioma cell viability and enhanced cisplatin-induced apoptosis in glioma cells. AKT activation and the expression of various cell cycle-related genes were inhibited following LRF knockdown. The effect on growth and migration is related to dose response results of AKT and nuclear factor-kappa B (NF-κB) inhibitors. These data demonstrate that LRF may play a role in glioma progression, suggesting that inhibition of LRF expression using LRF shRNA should be further evaluated as a novel target for the control of glioma.

Role of Cdk1 in the p53-independent abrogation of the postmitotic checkpoint by human papillomavirus E6.

Specific types of human papillomavirus (HPV) are strongly associated with the development of cervical carcinoma. The HPV E6 oncoprotein from HPV degrades p53 and abrogates cell cycle checkpoints. Nonetheless, functional p53 has been observed in cervical cancer. We have previously identified a p53-independent function of E6 in attenuating the postmitotic G1-like checkpoint that can lead to polyploidy, an early event during cervical carcinogenesis that predisposes cells to aneuploidy. How E6 promotes cell cycle progression in the presence of p53 and its target, p21, remains a mystery. In this study, we examined the expression of cell cycle-related genes in cells expressing wild-type E6 and the mutant that is defective in p53 degradation but competent in abrogating the postmitotic checkpoint. Our results demonstrated an increase in the steady-state levels of G1- and G2-related cyclins/Cdks in E6-expressing keratinocytes. Interestingly, only Cdk1 remained active in E6 mutant-expressing cells while bypassing the postmitotic checkpoint. Furthermore, the downregulation of Cdk1 impaired the ability of both wild-type and mutant E6 to induce polyploidy. Our study thus demonstrated an important role for Cdk1, which binds p21 with lower affinity than Cdk2, in abrogating the postmitotic checkpoint in E6-expressing cells. We further show that E2F1 is important for E6 to upregulate Cdk1. Moreover, reduced nuclear p21 localization was observed in the E6 mutant-expressing cells. These findings shed light on the mechanisms by which HPV induces genomic instability and hold promise for the identification of drug targets. HPV infection is strongly associated with the development of cervical carcinoma. HPV encodes an E6 oncoprotein that degrades the tumor suppressor p53 and abrogates cell cycle checkpoints. Nonetheless, functional p53 has been observed in cervical cancer. We have recently demonstrated a p53-independent abrogation of the postmitotic checkpoint by HPV E6 that induces polyploidy. However, the mechanism is not known. In this study, we provide evidence that Cdk1 plays an important role in this process. Previously, Cdk2 was thought to be essential for the G1/S transition, while Cdk1 only compensated its function in the absence of Cdk2. Our studies have demonstrated a novel role of Cdk1 at the postmitotic G1-like checkpoint in the presence of Cdk2. These findings shed light on the mechanisms by which HPV induces genomic instability and hold promise for the identification of drug targets.