Cyclin E

Discovery of novel and highly potent anticancer agents enabled by selenium scanning of noscapine

Herein, the structural modification of noscapine via an elegant selenium scanning strategy has been demonstrated, which enables the production of three classes of novel seleno-containing noscapinoids, namely 6', 7', and 9'-seleno-substituted noscapines. Among them, 9'-seleno-substituted noscapines exhibited superior in vitro anti-proliferative activity, and 9'-cycloheptylselenomethyl-noscapine 17a16 with a large hydrophobic cycloheptyl group showed the most potent activity and good selectivity. Unlike most of the reported noscapinoids that induce G2/M phase arrest by targeting microtubules, 17a16 exhibited a distinct ability to induce S-phase arrest and displayed superior potency in inducing apoptosis, which attribute to the activation of two parallel checkpoint pathways orchestrating DNA damage response, including DNA-PKcs-dependent p53 stabilization and ATR-Chk1 axis activation. Dissecting the upstream mechanism revealed that 17a16 targets mitochondria and induces mitochondrial dysfunction. This study elucidates the interplay of mitochondrial stress, DNA damage response, p53 and ATR-Chk1 checkpoint activation in mediating the anticancer effects of 17a16. Furthermore, 17a16 treatment significantly suppressed tumor growth in p53-deficient JeKo-1 subcutaneous xenograft model in vivo, without inducing systemic toxicity. Overall, our findings highlight 17a16 as a promising lead compound in cancer therapy and demonstrate the potential of selenium scanning as a valuable strategy for anticancer drug discovery.

Nuclear Import Defects Drive Cell Cycle Dysregulation in Neurodegeneration

Neurodegenerative diseases (NDDs) and other age-related disorders have been classically defined by a set of key pathological hallmarks. Two of these hallmarks, cell cycle dysregulation (CCD) and nucleocytoplasmic transport (NCT) defects, have long been debated as being either causal or consequential in the pathology of accelerated aging. Specifically, aberrant cell cycle activation in post-mitotic neurons has been shown to trigger neuronal cell death pathways and cellular senescence. Additionally, NCT has been observed to be progressively dysregulated during aging and in neurodegeneration, where the increased subcellular redistribution of nuclear proteins such as TAR DNA-Binding Protein-43 (TDP43) to the cytoplasm is a primary driver of many NDDs. However, the functional significance of NCT defects as either a primary driver or consequence of pathology, and how the redistribution of cell cycle machinery contributes to neurodegeneration, remains unclear. Here, we describe that pharmacological inhibition of importin-β nuclear import is capable of perturbing cell cycle machinery both in mitotic neuronal cell lines and post-mitotic primary neurons in vitro. Our Nemf R86S mouse model of motor neuron disease, characterized by nuclear import defects, further recapitulates the hallmarks of CCD in mitotic cell lines and in post-mitotic primary neurons in vitro, and in spinal motor neurons in vivo. The observed CCD is consistent with the transcriptional and phenotypical dysregulation observed in neuronal cell death and cellular senescence in NDDs. Together, this evidence suggests that impairment of nuclear import pathways resulting in CCD may be a common driver of pathology in neurodegeneration.

FBXW7 in gastrointestinal cancers: from molecular mechanisms to therapeutic prospects

F-box and WD repeat domain-containing 7 (FBXW7), formerly known as hCdc4, hAGO Fbw7, or SEL10, plays a specific recognition function in SCF-type E3 ubiquitin ligases. FBXW7 is a well-established cancer suppressor gene that specifically controls proteasomal degradation and destruction of many key oncogenic substrates. The FBXW7 gene is frequently abnormal in human malignancies especially in gastrointestinal cancers. Accumulating evidence reveals that mutations and deletions of FBXW7 are participating in the occurrence, progression and treatment resistance of human gastrointestinal cancers. Considering the current therapeutic challenges faced by gastrointestinal cancers, elucidating the biological function and molecular mechanism of FBXW7 can provide new perspectives and references for future personalized treatment strategies. In this review, we elucidate the key molecular mechanisms by which FBXW7 and its substrates are involved in gastrointestinal cancers. Furthermore, we discuss the consequences of FBXW7 loss or dysfunction in tumor progression and underscore its potential as a prognostic and therapeutic biomarker. Lastly, we propose potential therapeutic strategies targeting FBXW7 to guide the precision treatment of gastrointestinal cancers.

Expression of GLOD4 in the Testis of the Qianbei Ma Goat and Its Effect on Leydig Cells

The expression pattern of GLOD4 in the testis and its regulatory effect on testicular cells was explored in goats to enhance our understanding of spermatogenesis and improve reproduction in breeding rams. In this study, we demonstrated the localization of GLOD4 in testicular cells using immunohistochemistry and subcellular localization analyses. Subsequently, we analyzed the GLOD4 expression pattern in four age-based groups (0, 6, 12, and 18 months old) using real-time quantitative polymerase chain reaction (qRT-PCR) and protein blotting. Finally, we performed GLOD4 silencing and overexpression studies in Leydig cells (LCs) and explored the effects on cell proliferation, the cell cycle, steroid hormone secretion and the expression of candidate testosterone hormone-regulated genes. GLOD4 was mainly expressed in Leydig cells, and the subcellular localization results showed that the GLOD4 protein was mainly localized in the cytoplasm and nucleus. Silencing of GLOD4 significantly suppressed the mRNA expression levels of the testosterone secretion-related genes CYP11A1, 3β-HSD, and CYP17A1 and the mRNA expression levels of cell cycle-related genes CDK6, PCNA, and Cyclin E. Moreover, the cell cycle was blocked at the G2/M phase after GLOD4 silencing, which significantly suppressed testosterone secretion. In contrast, GLOD4 overexpression significantly increased the mRNA expression levels of the testosterone secretion-related genes CYP11A1, 3β-HSD, and CYP17A1 and increased the expression of the cell cycle-related genes CDK6, PCNA, and Cyclin E. Moreover, GLOD4 overexpression promoted the cell cycle from G0/G1 phases to enter the S phase and G2/M phases, promoted the secretion of testosterone. Taken together, our experimental results indicate that GLOD4 may affect the development of cells in Qianbei Ma goats of different ages by influencing the cell cycle, cell proliferation, and testosterone hormone synthesis. These findings enhance our understanding of the functions of GLOD4 in goats.

Branched-chain amino acids prevent obesity by inhibiting the cell cycle in an NADPH-FTO-m6A coordinated manner

Obesity has become a major health crisis in the past decades. Branched-chain amino acids (BCAA), a class of essential amino acids, exerted beneficial health effects with regard to obesity and its related metabolic dysfunction, although the underlying reason is unknown. Here, we show that BCAA supplementation alleviates high-fat diet (HFD)-induced obesity and insulin resistance in mice and inhibits adipogenesis in 3T3-L1 cells. Further, we find that BCAA prevent the mitotic clonal expansion (MCE) of preadipocytes by reducing cyclin A2 (CCNA2) and cyclin-dependent kinase 2 (CDK2) expression. Mechanistically, BCAA decrease the concentration of nicotinamide adenine dinucleotide phosphate (NADPH) in adipose tissue and 3T3-L1 cells by reducing glucose-6-phosphate dehydrogenase (G6PD) expression. The reduced NADPH attenuates the expression of fat mass and obesity-associated (FTO) protein, a well-known m6A demethylase, to increase the N6-methyladenosine (m6A) levels of Ccna2 and Cdk2 mRNA. Meanwhile, the high m6A levels of Ccna2 and Cdk2 mRNA are recognized by YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), which results in mRNA decay and reduction of their protein expressions. Overall, our data demonstrate that BCAA inhibit obesity and adipogenesis by reducing CDK2 and CCNA2 expression via an NADPH-FTO-m6A coordinated manner in vivo and in vitro, which raises a new perspective on the role of m6A in the BCAA regulation of obesity and adipogenesis.

Tasmanian devil cathelicidins exhibit anticancer activity against Devil Facial Tumour Disease (DFTD) cells

The Tasmanian devil (Sarcophilus harrisii) is endangered due to the spread of Devil Facial Tumour Disease (DFTD), a contagious cancer with no current treatment options. Here we test whether seven recently characterized Tasmanian devil cathelicidins are involved in cancer regulation. We measured DFTD cell viability in vitro following incubation with each of the seven peptides and describe the effect of each on gene expression in treated cells. Four cathelicidins (Saha-CATH3, 4, 5 and 6) were toxic to DFTD cells and caused general signs of cellular stress. The most toxic peptide (Saha-CATH5) also suppressed the ERBB and YAP1/TAZ signaling pathways, both of which have been identified as important drivers of cancer proliferation. Three cathelicidins induced inflammatory pathways in DFTD cells that may potentially recruit immune cells in vivo. This study suggests that devil cathelicidins have some anti-cancer and inflammatory functions and should be explored further to determine whether they have potential as treatment leads.

Giant Cells of Various Lesions Are Characterised by Different Expression Patterns of HLA-Molecules and Molecules Involved in the Cell Cycle, Bone Metabolism, and Lineage Affiliation: An Immunohistochemical Study with a Review of the Literature

Giant cells (GCs) are thought to originate from the fusion of monocytic lineage cells and arise amid multiple backgrounds. To compare GCs of different origins, we immunohistochemically characterised the GCs of reactive and neoplastic lesions (n = 47). We studied the expression of 15 molecules including HLA class II molecules those relevant to the cell cycle, bone metabolism and lineage affiliation. HLA-DR was detectable in the GCs of sarcoidosis, sarcoid-like lesions, tuberculosis, and foreign body granuloma. Cyclin D1 was expressed by the GCs of neoplastic lesions as well as the GCs of bony callus, fibroid epulis, and brown tumours. While cyclin E was detected in the GCs of all lesions, p16 and p21 showed a heterogeneous expression pattern. RANK was expressed by the GCs of all lesions except sarcoid-like lesions and xanthogranuloma. All GCs were RANK-L-negative, and the GCs of all lesions were osteoprotegerin-positive. Osteonectin was limited to the GCs of chondroblastoma. Osteopontin and TRAP were detected in the GCs of all lesions except xanthogranuloma. RUNX2 was heterogeneously expressed in the reactive and neoplastic cohort. The GCs of all lesions except foreign body granuloma expressed CD68, and all GCs were CD163- and langerin-negative. This profiling points to a functional diversity of GCs despite their similar morphology.

Genomic landscape and expression profile of consensus molecular subtype four of colorectal cancer

Background

Compared to other subtypes, the CMS4 subtype is associated with lacking of effective treatments and poorer survival rates.

Methods

A total of 24 patients with CRC were included in this study. DNA and RNA sequencing were performed to acquire somatic mutations and gene expression, respectively. MATH was used to quantify intratumoral heterogeneity. PPI and survival analyses were performed to identify hub DEGs. Reactome and KEGG analyses were performed to analyze the pathways of mutated or DEGs. Single-sample gene set enrichment analysis and Xcell were used to categorize the infiltration of immune cells.

Results

The CMS4 patients had a poorer PFS than CMS2/3. CTNNB1 and CCNE1 were common mutated genes in the CMS4 subtype, which were enriched in Wnt and cell cycle signaling pathways, respectively. The MATH score of CMS4 subtype was lower. SLC17A6 was a hub DEG. M2 macrophages were more infiltrated in the tumor microenvironment of CMS4 subtype. The CMS4 subtype tended to have an immunosuppressive microenvironment.

Conclusion

This study suggested new perspectives for exploring therapeutic strategies for the CMS4 subtype CRC.

Effect of miR-493-5p on proliferation and differentiation of myoblast by targeting ANKRD17

The hypertrophy and conversion of postnatal muscle fibers largely determine the yield and quality of meat, which is closely related to the economic value of pigs. MicroRNA (miRNA), as a kind of endogenous noncoding RNA molecule, is widely involved in myogenesis of livestock and poultry. The longissimus dorsi tissues of Lantang pigs at 1 and 90 days (LT1D and LT90D) were collected and profiled by miRNA-seq. We found 1871 and 1729 miRNA candidates in LT1D and LT90D samples, and 794 miRNAs were shared. We identified 16 differentially expressed miRNAs between two tested groups and explored the function of miR-493-5p inmyogenesis. The miR-493-5p promoted the proliferation and inhibited the differentiation of myoblasts. Using GO and KEGG analyses of 164 target genes of miR-493-5p, we found that ATP2A2, PPP3CA, KLF15, MED28, and ANKRD17 genes were related to muscle development. RT-qPCR detection showed that the expression level of ANKRD17 was highly expressed in LT1D libraries, and the double luciferase report test preliminarily proved that miR-493-5p and ANKRD17 have a directly targeting relationship. We established miRNA profiles for the longissimus dorsi tissues of 1-day-old and 90-day-old Lantang pigs and found that miR-493-5p was differentially expressed and associated with myogenesis by targeting ANKRD17 gene. Our results should serve as a reference for future studies on pork quality.

Regulation of neural stem cell self-renewal, proliferation and differentiation by the RhoA guanine nucleotide exchange factor Arhgef 1

The role of the Arhgef1 as a RhoA-specific guanine nucleotide exchange factor has been widely investigated in the immune system. Our previous findings reveal that Arhgef 1 is highly expressed in neural stem cells (NSCs) and controls the process of neurite formation. However, the functional role of Arhgef 1 in NSCs remains poorly understood. In order to investigate the role of Arhgef 1 in NSCs, Arhgef 1 expression in NSCs was reduced by using lentivirus-mediated short hairpin RNA interference. Our results indicate that down-regulated expression of Arhgef 1 reduced the self-renewal, proliferation capacity of NSCs and affect cell fate determination. In addition, the comparative transcriptome analysis from RNA-seq data determines the mechanisms of deficits in Arhgef 1 knockdown NSCs. Altogether, our present studies show that Arhgef 1 down-regulation leads to interruption of the cell cycle procession. The importance of Arhgef 1 for regulating self-renewal, proliferation and differentiation in NSCs is reported for the first time.

Lack of Cyclin E1 in hepatocytes aggravates ethanol-induced liver injury and hepatic steatosis in experimental murine model of acute and chronic alcohol-associated liver disease

BACKGROUND

Cyclin E1 is the regulatory subunit of cyclin-dependent kinase 2 (Cdk2) and one of the central players in cell cycle progression. We recently showed its crucial role for initiation of liver fibrosis and hepatocarcinogenesis. In the present study, we investigated the role of Cyclin E1 in the development of alcohol-associated liver disease (ALD).

METHODS

Mice with constitutive (E1^-/-), hepatocyte-specific (Cyclin E1^Δhepa), or intestinal-epithelial-cell-specific (Cyclin E1^ΔIEC) inactivation of Cyclin E1 and corresponding wild type littermate controls (WT) were administered either a Lieber-DeCarli ethanol diet (LDE) for 3 weeks or acute ethanol binges (6 g/kg) through oral gavage. Serum parameters of liver functionality were measured; hepatic tissues were collected for biochemical and histological analyses.

RESULTS

The administration of acute EtOH binge and chronic LDE diet to E1^-/- mice enhanced hepatic steatosis, worsened liver damage and triggered body weight loss. Similarly, in the acute EtOH binge model, Cyclin E1^Δhepa mice revealed a significantly worsened liver phenotype. In contrast, inactivation of Cyclin E1 only in intestinal epithelial cell (IECs)did not lead to any significant changes in comparison to WT mice after acute EtOH challenge. Remarkably, both acute and chronic EtOH administration in E1^-/- animals resulted in increased levels of ADH and decreased expression of ALDH1/2. The additional application of a pan-Cdk inhibitor (S-CR8) further promoted liver damage in EtOH-treated WT mice.

CONCLUSION

Our data point to a novel unexpected role of Cyclin E1 in hepatocytes for alcohol metabolism, which seems to be independent of the canonical Cyclin E1/Cdk2 function as a cell cycle regulator.

Bone Marrow Mesenchymal Stem Cells Expanded Inside the Nichoid Micro-Scaffold: a Focus on Anti-Inflammatory Response

Purpose

Mesenchymal stem cells (MSCs) represent a promising source for stem cell therapies in numerous diseases, including pediatric respiratory system diseases. Characterized by low immunogenicity, high anti-inflammatory, and immunoregulatory features, MSCs demonstrated an excellent therapeutic profile in numerous in vitro and preclinical models. MSCs reside in a specialized physiologic microenvironment, characterized by a unique combination of biophysical, biochemical, and cellular properties. The exploitation of the 3D micro-scaffold Nichoid, which simulates the native niche, enhanced the anti-inflammatory potential of stem cells through mechanical stimulation only, overcoming the limitation of biochemical and xenogenic growth factors application.

Materials and Methods

In this work, we expanded pediatric bone marrow MSCs (BM-MSCs) inside the Nichoid and performed a complete cellular characterization with different approaches including viability assays, immunofluorescence analyses, RNA sequencing, and gene expression analysis.

Results

We demonstrated that BM-MSCs inside the scaffold remain in a stem cell quiescent state mimicking the condition of the in vivo environment. Moreover, the gene expression profile of these cells shows a significant up-regulation of genes involved in immune response when compared with the flat control.

Conclusion

The significant changes in the expression profile of anti-inflammatory genes could potentiate the therapeutic effect of BM-MSCs, encouraging the possible clinical translation for the treatment of pediatric congenital and acquired pulmonary disorders, including post-COVID lung manifestations.

Lay Summary

Regenerative medicine is the research field integrating medicine, biology, and biomedical engineering. In this context, stem cells, which are a fundamental cell source able to regenerate tissues and restore damage in the body, are the key component for a regenerative therapeutic approach. When expanded outside the body, stem cells tend to differentiate spontaneously and lose regenerative potential due to external stimuli. For this reason, we exploit the scaffold named Nichoid, which mimics the in vivo cell niche architecture. In this scaffold, mesenchymal stem cells "feel at home" due to the three-dimensional mechanical stimuli, and our findings could be considered as an innovative culture system for the in vitro expansion of stem cells for clinical translation.

Future Perspective

The increasing demand of safe and effective cell therapies projects our findings toward the possibility of improving cell therapies based on the use of BM-MSCs, particularly for their clinical translation in lung diseases.

Graphical Abstract

Biomarkers of disease recurrence in stage I testicular germ cell tumours

Stage I testicular cancer is a disease restricted to the testicle. After orchiectomy, patients are considered to be without disease; however, the tumour is prone to relapse in ~4-50% of patients. Current predictive markers of relapse, which are tumour size and invasion to rete testis (in seminoma) or lymphovascular invasion (in non-seminoma), have limited clinical utility and are unable to correctly predict relapse in a substantial proportion of patients. Adjuvant therapeutic strategies based on available biomarkers can lead to overtreatment of 50-85% of patients. Discovery and implementation of novel biomarkers into treatment decision making will help to reduce the burden of adjuvant treatments and improve patient selection for adjuvant therapy.

Planar cell polarity: intracellular asymmetry and supracellular gradients of Dachsous

The slope of a supracellular molecular gradient has long been thought to orient and coordinate planar cell polarity (PCP). Here we demonstrate and measure that gradient. Dachsous (Ds) is a conserved and elemental molecule of PCP; Ds forms intercellular bridges with another cadherin molecule, Fat (Ft), an interaction modulated by the Golgi protein Four-jointed (Fj). Using genetic mosaics and tagged Ds, we measure Ds in vivo in membranes of individual cells over a whole metamere of the Drosophila abdomen. We find as follows. (i) A supracellular gradient rises from head to tail in the anterior compartment (A) and then falls in the posterior compartment (P). (ii) There is more Ds in the front than the rear membranes of all cells in the A compartment, except that compartment's most anterior and most posterior cells. There is more Ds in the rear than in the front membranes of all cells of the P compartment. (iii) The loss of Fj removes intracellular asymmetry anteriorly in the segment and reduces it elsewhere. Additional experiments show that Fj makes PCP more robust. Using Dachs (D) as a molecular indicator of polarity, we confirm that opposing gradients of PCP meet slightly out of register with compartment boundaries.

The Novel Diagnostic Techniques and Biomarkers of Canine Mammary Tumors

Canine mammary tumors (CMTs) are considered a serious clinical problem in older bitches. Due to the high malignancy rate and poor prognosis, an early diagnosis is essential. This article is a summary of novel diagnostic techniques as well as the main biomarkers of CMTs. So far, CMTs are detected only when changes in mammary glands are clinically visible and surgical removal of the mass is the only recommended treatment. Proper diagnostics of CMT is especially important as they represent a very diverse group of tumors and therefore different treatment approaches may be required. Recently, new diagnostic options appeared, like a new cytological grading system of CMTs or B-mode ultrasound, the Doppler technique, contrast-enhanced ultrasound, and real-time elastography, which may be useful in pre-surgical evaluation. However, in order to detect malignancies before macroscopic changes are visible, evaluation of serum and tissue biomarkers should be considered. Among them, we distinguish markers of the cell cycle, proliferation, apoptosis, metastatic potential and prognosis, hormone receptors, inflammatory and more recent: metabolomic, gene expression, miRNA, and transcriptome sequencing markers. The use of a couple of the above-mentioned markers together seems to be the most useful for the early diagnosis of neoplastic diseases as well as to evaluate response to treatment, presence of tumor progression, or further prognosis. Molecular aspects of tumors seem to be crucial for proper understanding of tumorigenesis and the application of individual treatment options.

BMP6 Promotes the Secretion of 17 Beta-Estradiol and Progesterone in Goat Ovarian Granulosa Cells

The purpose of this study was to investigate the effects of BMP6 on the function of goat ovarian granulosa cells (GCs). The results showed that the exogenous addition of BMP6 did not affect the EdU-positive ratio of ovarian GCs and had no significant effect on the mRNA and protein expression levels of the proliferation-related gene PCNA (p > 0.05). Meanwhile, BMP6 had no significant effect on the cycle phase distribution of GCs but increased the mRNA expression of CDK4 (p < 0.05) and CCND1 (p < 0.01) and decreased the mRNA expression of CCNE1 (p < 0.01). Moreover, BMP6 had no significant effect on the apoptosis rate of GCs and did not affect the mRNA expression levels of apoptosis-related genes BAX, BCL2, and Caspase3 (p > 0.05). Importantly, BMP6 upregulated the secretion of 17 beta-estradiol (E2) and progesterone (P4) in ovarian GCs (p < 0.01). Further studies found that BMP6 inhibited the mRNA expression of 3β-HSD and steroid synthesis acute regulator (StAR) but significantly promoted the mRNA expression of the E2 synthesis rate-limiting enzyme CYP19A1 and the P4 synthesis rate-limiting enzyme CYP11A1 (p < 0.01). Taken together, these results showed that the exogenous addition of BMP6 did not affect the proliferation, cell cycle, and apoptosis of goat ovarian GCs but promoted the secretion of E2 and progesterone P4 in ovarian GCs by upregulating the mRNA expressions of CYP19A1 and CYP11A1.

DZW-310, a novel phosphoinositide 3-kinase inhibitor, attenuates the angiogenesis and growth of hepatocellular carcinoma cells via PI3K/AKT/mTOR axis

Hepatocellular carcinoma (HCC) is one of the most malignant tumors worldwide with high lethality and prevalence. The deregulated phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway plays an indispensable role in mediating the progression of HCC. Among them, PI3K acts as the most pivotal initiator, contributing to multiple malignant biological processes, like proliferation, apoptosis and angiogenesis. Many PI3K inhibitors (PI3Kis) have been proved or proceeded into clinical as antineoplastic drugs. Nevertheless, the application of PI3Kis for the treatment of HCC remains a blank. Accordingly, our study identified a novel PI3Ki (DZW-310) with strong anti-HCC activity in vitro and in vivo. This study aimed to evaluate its anti-HCC effect and elucidate its potential mechanism. Our current results revealed that DZW-310 significantly attenuated HCC cell growth through promoting intrinsic apoptosis and G0/G1 phase cell arrest. Moreover, DZW-310 suppressed angiogenesis by regulating the HIF-1α/VEGFA axis. Further mechanistic investigation demonstrated that DZW-310, functioned as a PI3Ki, exerted strong anti-HCC activity by acting on PI3Kα (a major subtype of PI3K) and ulteriorly deactivating the PI3K/AKT/mTOR pathway. Collectively, our studies identified that DZW-310 is expected to become a promising HCC therapeutic agent and broaden clinical application of PI3Ki in HCC chemotherapy.

Role of Genetic Variations in CDK2, CCNE1 and p27KIP1 in Prostate Cancer

BACKGROUND/AIM

Our aim was to investigate possible influences of genetic variants in genes involved in the G₁/S transition [cyclin-dependent kinase-2 (CDK2), cyclin E1 (CCNE1) and cyclin-dependent kinase inhibitor 1B (p27^KIP1)] on the expression/activity of their corresponding proteins and to assess the functional impact of these variants on the risk of prostate cancer.

MATERIALS AND METHODS

We genotyped 530 cases and 562 healthy controls for two relevant single nucleotide polymorphisms (CDK2 rs2069408 and CCNE1 rs997669) by TaqMan genotyping assay. p27^KIP1 rs2066827 polymorphisms were studied by polymerase chain reaction-restriction fragment length polymorphism assay. In addition, the expression of CDK2, CCNE1 and p27^KIP1 was evaluated by quantitative real-time-polymerase chain reaction and western blotting in 44 prostate cancer tissues and 31 benign prostatic hyperplasia tissues.

RESULTS

No association was found between CDK2 rs2069408, CCNE1 rs997669 or p27^KIP1 rs2066827 polymorphisms and an increased risk of prostate cancer development. Higher CDK2 expression was more prevalent in those with rs2069408 GG genotype than in AA carriers (p>0.05). We also noted reduced p27^KIP1 protein expression in those with the p27^KIP1 G109 allele. No difference was observed for CCNE1 expression in relation to the risky genotype (CC). A significant association was detected between CCNE1 mRNA overexpression and development of higher-grade carcinomas (Gleason score >7, p<0.05).

CONCLUSION

Polymorphisms CDK2 rs2069408, CCNE1 rs997669 and p27^KIP1 rs2066827 have no significant impact on prostate cancer risk nor on the gene and protein expression of CDK2, CCNE1 and p27^KIP1, although high CCNE1 expression was significantly associated with a higher tumour grade in patients with prostate cancer.

Downregulation of FTL decreases proliferation of malignant mesothelioma cells by inducing G1 cell cycle arrest

Pleural malignant mesothelioma is a malignant tumor with a poor prognosis that is strongly associated with asbestos exposure during its development. Because there is no adequate treatment for malignant mesothelioma, investigation of its molecular mechanism is important. The ferritin light chain (FTL) is a subunit of ferritin, and its high expression in malignant tumors, including malignant mesothelioma, has recently been reported; however, its role in malignant mesothelioma is unclear. The purpose of the present study was to clarify the function of FTL in malignant mesothelioma. The expression levels of FTL in malignant mesothelioma were examined using the Cancer Cell Line Encyclopedia database and our previous data. The short interfering (si)RNA against FTL was transfected into two mesothelioma cell lines, ACC-MESO-1 and CRL-5915, and functional analysis was performed. Expression of p21, p27, cyclin-dependent kinase 2 (CDK2) and phosphorylated retinoblastoma protein (pRb) associated with the cell cycle were examined as candidate genes associated with FTL. The expression levels of the FTL mRNA were higher in malignant mesothelioma compared with other tumors in the Cancer Cell Line Encyclopedia database, and among other genes in our previous study. Reverse transcription-quantitative PCR and western blotting demonstrated suppression of FTL expression in two cell lines transfected with FTL siRNA compared with cells transfected with negative control (NC) siRNA. In the two cell lines transfected with FTL siRNA, proliferation was significantly suppressed, and cell cycle arrest was observed in the G₁ phase. The levels of p21 and p27 were increased, while those of CDK2 and pRb were decreased compared with NC. However, no significant differences in invasion and migration ability were revealed between FTL siRNA-transfected cells and NC. In conclusion, FTL may increase the proliferative capacity of malignant mesothelioma cells by affecting p21, p27, CDK2 and pRb, and promoting the cell cycle at the G₁ phase.

Sex differences in the early life stages of the salmon louse Lepeophtheirus salmonis (Copepoda: Caligidae)

Salmon lice are ectoparasites on salmonids and feed on blood, mucus, and skin from their hosts. This causes high annual costs for treatment and control for the aquaculture industry. Salmon lice have a life cycle consisting of eight life stages. Sex determination by eye is only possible from the sixth stage onwards. A molecular sex determination has not been carried out so far, even though few individual sex-linked SNPs have been reported. In the present study, we used known sex-specific SNPs as a basis to sequence the complete sex-specific gene variants and used the sequence information to develop a sex determination assay. This assay could be used to determine the developmental speed of the two sexes already in the earliest life stages. Additionally, we sampled salmon lice in the nauplius II stage, determined the sex of each individual, pooled their RNA according to their sex, and used RNA sequencing to search for differences in gene expression and further sex-specific SNPs. We succeeded in developing a sex-determination assay that works on DNA or RNA from even the earliest larval stages of the salmon louse after hatching. At these early developmental stages, male salmon lice develop slightly quicker than females. We detected several previously unknown, sex-specific SNPs in our RNA-data seq, but only very few genes showed a differential expression between the sexes. Potential connections between SNPs, gene expression, and development are discussed.

CCNE1 promotes progression and is associated with poor prognosis in lung adenocarcinoma

BACKGROUND

Mounting evidence has shown that Cyclin E1 (CCNE1) facilitates various carcinoma progression, but its function in lung adenocarcinoma (LUAD) remains unclear.

OBJECTIVE

Our study aims to explore the significance of CCNE1 in clinical progression and study its biological functions in LUAD.

METHODS

CCNE1 expressions in LUAD specimens and cells were detected through quantitative realtime polymerase chain reaction (qRT-RCR) and western blot. An immunohistochemistry technique was used to detect CCNE1 expression to explore its association with clinical parameters. The LUAD cells with stable knockdown of CCNE1 were constructed by small interfering RNA. The effect of CCNE1 on LUAD cells proliferation and apoptosis was evaluated through Cell Counting Kit-8 (CCK-8), colony formation, and Annexin V/propidium iodide (AV-PI) assays, respectively. The cell migration and invasion were evaluated by Wound-healing and Transwell assays, respectively. The xenograft and lung metastasis mouse models were introduced to analyze how CCNE1 knockdown affects tumor growth and tumor metastasis.

RESULTS

CCNE1 expression was upregulated in LUAD tissue and cells. CCNE1 knockdown inhibited LUAD cellular malignant behavior in vitro and reduced tumor growth and metastasis in vivo. High expression of CCNE1 was correlated with big tumor size, cancer stage, lymph node metastasis, and poor prognosis.

CONCLUSIONS

CCNE1 overexpression promotes LUAD growth, metastasis, and forebode poor prognosis: it can serve as a new prognostic marker of LUAD.

CCNE1 amplification among metastatic sites in patients with gynecologic high-grade serous carcinoma

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CCNE1 amplification is conserved among metastatic sites in CCNE1-amplified high-grade serous carcinomas.

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Limited CCNE1 copy number heterogeneity among CCNE1-amplified cases suggests some genomic change during metastasis.

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Digital droplet PCR can be used to quantify CCNE1 copy number from archival specimens of high-grade serous carcinomas.

Objective

We sought to characterize the variability of CCNE1 amplification among metastatic sites of CCNE1 amplified high grade serous carcinoma (HGSC) cases to investigate the feasibility of targeting this alteration for therapeutic purposes.

Methods

Patients with CCNE1 amplified HGSC who underwent surgical cytoreduction with metastatic sites were identified from institutional molecular profiling reports and a population of HGSC cases screened using digital droplet PCR (ddPCR). Cases with normal CCNE1 copy number were included as controls. Slides from metastatic sites were cut from formalin-fixed paraffin-embedded tissue blocks, dissected for tumor of > 50% purity, and underwent DNA extraction. CCNE1 copy number was determined by ddPCR. Tumor purity was confirmed with mutant TP53 allele fraction from targeted massively parallel sequencing.

Results

Four of 15 patients from an institutional database screened by ddPCR were found to have CCNE1 amplification. Three additional patients were identified from a query of institutional commercial clinical reports. Among these 7 CCNE1 amplified cases (2 uterine, 5 ovarian), 5 showed preservation of CCNE1 amplification (copy number > 5) among all metastatic sites. The remaining 2 cases had multiple metastatic sites without preserved CCNE1 amplification. Non-amplified cases had predominantly normal CCNE1 copy number across metastatic sites.

Conclusions

CCNE1 amplification is an early genomic event in HGSC and is preserved in most metastatic sites suggesting a uniform response to pathway targeting therapies.

MicroRNAs Involved in Small-cell Lung Cancer as Possible Agents for Treatment and Identification of New Targets

Small-cell lung cancer, a neuro-endocrine type of lung cancers, responds very well to chemotherapy-based agents. However, a high frequency of relapse due to adaptive resistance is observed. Immunotherapy-based treatments with checkpoint inhibitors has resulted in improvement of treatment but the responses are not as impressive as in other types of tumor. Therefore, identification of new targets and treatment modalities is an important issue. After searching the literature, we identified eight down-regulated microRNAs involved in radiation- and chemotherapy-induced resistance, as well as three up-regulated and four down-regulated miRNAs with impacts on proliferation, invasion and apoptosis of small-cell lung cancer cells in vitro. Furthermore, one up-regulated and four down-regulated microRNAs with in vivo activity in SCLC cell xenografts were identified. The identified microRNAs are candidates for inhibition or reconstitution therapy. The corresponding targets are candidates for inhibition or functional reconstitution with antibody-based moieties or small molecules.

Identification of abnormally high expression of POGZ as a new biomarker associated with a poor prognosis in osteosarcoma

Osteosarcoma (OS) is the most prevalent malignant bone tumor in children and young adults. There is an urgent need for a novel biomarker related to the prognosis of OS. We performed a meta-analysis incorporating six independent datasets and performed a survival analysis with one independent dataset GSE21257 in the GEO database for gene screening. The results revealed that one potential biomarker related to OS survival, POGZ was the most significantly upregulated gene. We also verified that the POGZ was overexpressed in clinical samples. The survival analysis revealed that POGZ is associated with a poor prognosis in OS. Moreover, flow cytometry analysis of isolated OS cells demonstrated that OS cells were arrested in the G1 phase after POGZ knockdown. The RNA-seq results indicated that POGZ was co-expressed with CCNE1 and CCNB1. Pathway analysis showed that genes associated with high expression levels of POGZ were related to the cell cycle pathway. A cell model was constructed to detect the effects of POGZ. After POGZ knockdown, OS cell proliferation, invasion and migration were all decreased. Therefore, POGZ is an important gene for evaluating the prognosis of OS patients and is a potential therapeutic target.

Microfragmented adipose tissue is associated with improved ex vivo performance linked to HOXB7 and b-FGF expression

INTRODUCTION

Adipose tissue (AT) has become a source of mesenchymal stromal/stem cells (MSC) for regenerative medicine applications, in particular skeletal disorders. Several enzymatic or mechanical procedures have been proposed to process AT with the aim to isolate cells that can be locally implanted. How AT is processed may impact its properties. Thus, we compared AT processed by centrifugation (C-AT) to microfragmentation (MF-AT). Focusing on MF-AT, we subsequently assessed the impact of synovial fluid (SF) alone on both MF-AT and isolated AT-MSC to better understand their cartilage repair mechanisms.

MATERIALS AND METHODS

MF-AT and C-AT from the same donors were compared by histology and qRT-PCR immediately after isolation or as ex vivo cultures using a micro-tissue pellet system. The in vitro impact of SF on MF-AT and AT-MSC was assessed by histological staining and molecular analysis.

RESULTS

The main AT histological features (i.e., increased extracellular matrix and cellularity) of the freshly isolated or ex vivo-cultured MF-AT persisted compared to C-AT, which rapidly deteriorated during culture. Based on our previous studies of HOX genes in MSC, we investigated the involvement of Homeobox Protein HOX-B7 (HOXB7) and its target basic Fibroblast Growth Factor (bFGF) in the molecular mechanism underlying the improved performance of MF-AT. Indeed, both these biomarkers were more prominent in freshly isolated MF-AT compared to C-AT. SF alone preserved the AT histological features of MF-AT, together with HOXB7 and bFGF expression. Increased cell performance was also observed in isolated AT-MSC after SF treatment concomitant with enhanced HOXB7 expression, although there was no apparent association with bFGF.

CONCLUSIONS

Our findings show that MF has a positive effect on the maintenance of AT histology and may trigger the expression of trophic factors that improve tissue repair by processed AT.

Effect of the phenylpyrrole fungicide fludioxonil on cell proliferation and cardiac differentiation in mouse embryonic stem cells

Fludioxnil is extensively used as a fungicide in agricultural application, but its possible impact on embryonic development is not yet well understood. In this study, the potential effect of fludioxonil on cardiac differentiation was evaluated in mouse embryonic stem cells (mESCs). The water-soluble tetrazolium (WST) and colony formation assays were conducted to confirm the effect of fludioxonil on proliferation of mESCs. The effect of fludioxonil on the ability of mESCs to form mouse embryoid bodies (mEBs) was determined by the hanging drop assay, whereas the ability of cardiomyocyte differentiation in the early stage was evaluated by determining the beating ratio (ratio of the number of contracting cells to the number of attached EBs) of cardiomyocytes. The viability of mESCs was significantly decreased (less than 50 %) at 10^-5 M fludioxonil. Results of the colony formation assay revealed suppressed colony formation at 10^-5 M fludioxonil (about 50 % at 5 days). Furthermore, the expressions of cell-cycle related proteins, i.e., cyclin D1, cyclin E, p21 and p27, were altered and trending towards inhibiting cell growth. Exposure to fludioxonil also resulted in reduced size of the mEB and induced increasing expression levels of the pluripotency markers Oct4, Sox2 and Nanog. Development of the beating ratio in the process of differentiation to cardiomyocytes derived from mESCs was completely inhibited after exposure to 10^-5 M fludioxonil during the early stage of differentiation (day 5), whereas the beating ratio gradually increased after 5-day treatment. Simultaneously, expressions of the cardiomyocyte-related proteins, Gata4, Hand1 and cTnI, were inhibited after exposure to 10^-5 M fludioxonil. Taken together, these results imply that fludioxonil may impact on the developmental process of mESCs, particularly the cardiac lineage.

Identification of Somatic Gene Signatures in Circulating Cell-Free DNA Associated with Disease Progression in Metastatic Prostate Cancer by a Novel Machine Learning Platform

PURPOSE

Progression from metastatic castration-sensitive prostate cancer (mCSPC) to a castration-resistant (mCRPC) state heralds the lethal phenotype of prostate cancer. Identifying genomic alterations associated with mCRPC may help find new targets for drug development. In the majority of patients, obtaining a tumor biopsy is challenging because of the predominance of bone-only metastasis. In this study, we hypothesize that machine learning (ML) algorithms can identify clinically relevant patterns of genomic alterations (GAs) that distinguish mCRPC from mCSPC, as assessed by next-generation sequencing (NGS) of circulating cell-free DNA (cfDNA).

EXPERIMENTAL DESIGN

Retrospective clinical data from men with metastatic prostate cancer were collected. Men with NGS of cfDNA performed at a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory at time of diagnosis of mCSPC or mCRPC were included. A combination of supervised and unsupervised ML algorithms was used to obtain biologically interpretable, potentially actionable insights into genomic signatures that distinguish mCRPC from mCSPC.

RESULTS

GAs that distinguish patients with mCRPC (n = 187) from patients with mCSPC (n = 154) (positive predictive value = 94%, specificity = 91%) were identified using supervised ML algorithms. These GAs, primarily amplifications, corresponded to androgen receptor, Mitogen-activated protein kinase (MAPK) signaling, Phosphoinositide 3-kinase (PI3K) signaling, G1/S cell cycle, and receptor tyrosine kinases. We also identified recurrent patterns of gene- and pathway-level alterations associated with mCRPC by using Bayesian networks, an unsupervised machine learning algorithm.

CONCLUSION

These results provide clinical evidence that progression from mCSPC to mCRPC is associated with stereotyped concomitant gain-of-function aberrations in these pathways. Furthermore, detection of these aberrations in cfDNA may overcome the challenges associated with obtaining tumor bone biopsies and allow contemporary investigation of combinatorial therapies that target these aberrations.

IMPLICATIONS FOR PRACTICE

The progression from castration-sensitive to castration-resistant prostate cancer is characterized by worse prognosis and there is a pressing need for targeted drugs to prevent or delay this transition. This study used machine learning algorithms to examine the cell-free DNA of patients to identify alterations to specific pathways and genes associated with progression. Detection of these alterations in cell-free DNA may overcome the challenges associated with obtaining tumor bone biopsies and allow contemporary investigation of combinatorial therapies that target these aberrations.

HER2-targeted therapies in gastric cancer

Molecular targeted therapy of cancer has always been the focus of clinicians. Among those therapeutic targets, the human epidermal growth factor receptor-2 (HER-2) signaling pathway is one of the most popular targets for translational research in cancer. However, unlike prospect in breast cancer, HER-2 inhibitor trastuzumab is the only molecular targeted drug approved by US Food and Drug Administration (FDA) for the first-line treatment of HER-2 positive advanced gastric cancer. On this basis, a variety of novel HER2- targeted drugs for gastric cancer are under development, and related clinical researches are in full swing, including small molecular kinase inhibitors (e.g., afatinib, neratinib, pyrotinib), antibody-drug conjugates (e.g., DS-8201a, RC48-ADC) and other novel therapies (e.g., ZW25, CAR-T, BVAC-B). In this study, we will summarize the recent advances in anti-HER-2 agents, potential mechanisms of resistance to HER2-targeted therapy in HER2-positive gastric cancer. We will also discuss the future prospects of potential strategies to overcome anti-HER-2 resistance and development of novel anti-HER-2 approaches for the treatment of HER2-positive gastric cancer patients.

Uncovering the Pharmacological Mechanism of 2-Dodecyl-6-Methoxycyclohexa-2,5 -Diene-1,4-Dione Against Lung Cancer Based on Network Pharmacology and Experimental Evaluation

Background: 2-Dodecyl-6-Methoxycyclohexa-2, 5-Diene-1,4-Dione (DMDD) was purified from the roots of Averrhoa carambola L. Previous research demonstrated that DMDD is a small molecular compound with significant therapeutic potential for tumors. However, the potential targets and pharmacological mechanism of DMDD to treat lung cancer has not been reported.

Methods: We employed network pharmacology and experimental evaluation to reveal the pharmacological mechanism of DMDD against lung cancer. Potential therapeutic targets of DMDD were screened by PharmMapper. Differentially expressed genes (DEGs) in The Cancer Genome Atlas (TCGA) lung cancer data sets were extracted and analyzed by GEPIA2. The mechanism of DMDD against lung cancer was determined by PPI, gene ontology (GO) and KEGG pathway enrichment analysis. Survival analysis and molecular docking were employed to obtain the key targets of DMDD. Human lung cancer cell lines H1975 and PC9 were used to detect effects of DMDD treatment in vitro. The expression of key targets after DMDD treated was validated by Western Blot.

Results: A total of 60 Homo sapiens potential therapeutic targets of DMDD and 3,545 DEGs in TCGA lung cancer datasets were identified. Gene ontology and pathway analysis revealed characteristic of the potential targets of DMDD and DEGs in lung cancer respectively. Cell cycle and pathways in cancer were overlapping with DMDD potential targets and lung cancer DEGs. Eight overlapping genes were found between DMDD potential therapeutic targets and lung cancer related DEGs. Survival analysis showed that high expression of DMDD potential targets CCNE1 and E2F1 was significantly related to poor patient survival in lung cancer. Molecular docking found that DMDD exhibited significant binding affinities within the active site of CCNE1 and E2F1. Further tests showed that DMDD inhibited the proliferation, migration and clone formation in lung cancer cell lines (H1975 and PC9) in a dose and time dependent manner. Mechanistically, DMDD treatment decreased the expression of CDK2, CCNE1, E2F1 proteins and induced cell cycle arrest at the G1/S phase in H1975 and PC9 cells.

Conclusion: These results delineated that DMDD holds therapeutic potential that blocks tumorigenesis by cell cycle regulation in lung cancer, and may provide potential therapies for lung cancer.

Jasmonates induce Arabidopsis bioactivities selectively inhibiting the growth of breast cancer cells through CDC6 and mTOR

Phytochemicals are used often in vitro and in vivo in cancer research. The plant hormones jasmonates (JAs) control the synthesis of specialized metabolites through complex regulatory networks. JAs possess selective cytotoxicity in mixed populations of cancer and normal cells. Here, direct incubation of leaf explants from the non-medicinal plant Arabidopsis thaliana with human breast cancer cells, selectively suppresses cancer cell growth. High-throughput LC-MS identified Arabidopsis metabolites. Protein and transcript levels of cell cycle regulators were examined in breast cancer cells. A synergistic effect by methyljasmonate (MeJA) and by compounds upregulated in the metabolome of MeJA-treated Arabidopsis leaves, on the breast cancer cell cycle, is associated with Cell Division Cycle 6 (CDC6), Cyclin-dependent kinase 2 (CDK2), Cyclins D1 and D3, indicating that key cell cycle components mediate cell viability reduction. Bioactives such as indoles, quinolines and cis-(+)-12-oxophytodienoic acid, in synergy, could act as anticancer compounds. Our work suggests a universal role for MeJA-treatment of Arabidopsis in altering the DNA replication regulator CDC6, supporting conservation, across kingdoms, of cell cycle regulation, through the crosstalk between the mechanistic target of rapamycin, mTOR and JAs. This study has important implications for the identification of metabolites with anti-cancer bioactivities in plants with no known medicinal pedigree and it will have applications in developing disease treatments.

Copy number variations in primary tumor, serum and lymph node metastasis of bladder cancer patients treated with radical cystectomy

The aim of the present study was to analyze copy number variations (CNV) of multiple oncogenes and tumor suppressor genes in genomic DNA from primary tumor tissue, lymph node metastasis and cell-free DNA (cfDNA) from serum of 72 urothelial carcinoma of bladder (UCB) patients treated with radical cystectomy (RC), using multiplex ligation-dependent probe amplification (MLPA). We hypothesized that primary tumor and lymph node metastasis show similar CNV profiles, and CNV are more present in lymph node metastasis compared to primary tumor tissue. Samples from 43 (59.7%) patients could be analyzed. In total, 35 (83%), 26 (68%) and 8 (42%) patients had CNV in primary tumor, serum and lymph node metastasis, respectively. MYC, CCND1, ERBB2 and CCNE1 displayed the most frequent amplifications. In particular, CNV in ERBB2 was associated with aggressive tumor characteristics. CNV in both ERBB2 and TOP2A were risk factors for disease recurrence. The current findings show that CNV are present in various oncogenes and tumor suppressor genes in genomic DNA from primary tumor, lymph node metastasis and cfDNA from serum. CNV were more present in genomic DNA from primary tumor tissue compared to cfDNA from serum and genomic DNA from lymph node metastasis. Patients with CNV in ERBB2 and TOP2A are at increased risk for disease recurrence following RC. Further studies are necessary to validate, whether these genes may represent promising candidates for targeted-therapy.

Honokiol protects against epidural fibrosis by inhibiting fibroblast proliferation and extracellular matrix overproduction in rats post‑laminectomy

Epidural fibrosis (EF)‑induced failed back surgery syndrome (FBSS) in patients post‑laminectomy remains a medical challenge. Although the scarring mechanisms remain unclear, the majority of aetiological studies have reported fibroblast dysfunction. Honokiol, the major bioactive constituent of the magnolia tree, exerts a variety of pharmacological effects, including anti‑proliferative and anti‑fibrotic effects, on various cell types. The present study investigated whether honokiol attenuates EF progression. In vitro, it was found that honokiol inhibited excessive fibroblast proliferation induced by transforming growth factor‑β1 (TGF‑β1) and the synthesis of extracellular matrix (ECM) components, including fibronectin and type I collagen, in a dose‑dependent manner. These effects were attributed to the ability of honokiol to suppress the activity of connective tissue growth factor (CTGF), which is indispensable for the progression of fibrosis. Mechanistically, honokiol attenuated the TGF‑β1‑induced activation of the Smad2/3 and mitogen‑activated protein kinase (MAPK) signalling pathways in fibroblasts. In vivo, honokiol reduced the proliferation of fibroblasts and the synthesis of ECM components, thus ameliorating EF in a rat model post‑laminectomy. Taken together, these preclinical findings suggest that honokiol deserves further consideration as a candidate therapeutic agent for EF.

Mutual antagonism between Hippo signaling and cyclin E drives intracellular pattern formation

Not much is known about how organelles organize into patterns. In ciliates, the cortical pattern is propagated during "tandem duplication," a cell division that remodels the parental cell into two daughter cells. A key step is the formation of the division boundary along the cell's equator. In Tetrahymena thermophila, the cdaA alleles prevent the formation of the division boundary. We find that the CDAA gene encodes a cyclin E that accumulates in the posterior cell half, concurrently with accumulation of CdaI, a Hippo/Mst kinase, in the anterior cell half. The division boundary forms between the margins of expression of CdaI and CdaA, which exclude each other from their own cortical domains. The activities of CdaA and CdaI must be balanced to initiate the division boundary and to position it along the cell's equator. CdaA and CdaI cooperate to position organelles near the new cell ends. Our data point to an intracellular positioning mechanism involving antagonistic Hippo signaling and cyclin E.

Rab5 regulates the proliferation, migration and invasion of glioma cells via cyclin E

Glioma is the most common and lethal type of primary brain tumor, with a high mortality and recurrence rate. Rab5, which serves as a classic ontogenetic gene, is highly expressed in various types of tumor, including lung cancer, hepatocellular carcinoma and ovarian cancer. However, the exact role and the underlying mechanism of Rab5 in glioma remain unknown. Herein, the role of Rab5 in the tumorigenesis and metastasis of glioma cells was investigated. The upregulation of Rab5 in glioma tissues and cells was observed. The expression of Rab5 was positively associated with proliferation, migration and invasion of glioma cells. Moreover, Rab5 was involved in the cell cycle of glioma cells via the regulation of cyclin E. Data presented in the present study suggest Rab5 as a potential novel diagnostic and prognosis marker of glioma.

CARM1 promotes non-small cell lung cancer progression through upregulating CCNE2 expression

The underlying molecular mechanisms of tumorigenesis and progression of non-small cell lung cancer (NSCLC) are not yet fully elucidated. In the present study, invitro functional dissections suggest that siRNA-mediated silencing of CCNE2 profoundly attenuated the proliferative and colony-formative abilities of NSCLC PC9 and HCC827 cells, while forced overexpression of CCNE2 significantly strengthened the proliferative and colony-formative capabilities of these cells. Intriguingly, by ChIP and luciferase reporter gene assays, we observed that CARM1 is recruited to the promoter regions of CCNE2 gene and acts as a transcriptional activator. Mechanically, the asymmetric di-methylation of H3R17me2a and H3R26me2a, as the catalytic substrates of CARM1, were highly enriched at the core promoter regions of CCNE2 gene, thereby activating the expression of CCNE2. In vitro and in vivo rescue experiments demonstrated that restoration of CCNE2 expression significantly abolished the CARM1 shRNA-mediated inhibition of cell proliferation, indicating that the oncogenic function of CARM1, at least partially, depended on the activation of CCNE2. Inhibition of CARM1 enzymatic activity could significantly repress CCNE2 expression in NSCLC cells. In addition, the expression of CARM1 was significantly elevated and positively correlated with CCNE2 levels in 20 cases of NSCLC patients. Both CARM1 and CCNE2 are highly associated with shorter 10-year overall survival of at a large cohort of 461 cases of NSCLC patients from the Kaplan-Meier plotter database. To summarize, these findings provide compelling evidence that CARM1 could promote NSCLC progression via activation of CCNE2, paving the way for future therapeutic strategies in NSCLC.

Regulation of Cyclin E by transcription factors of the naïve pluripotency network in mouse embryonic stem cells

Continuous, non-cell cycle-dependent expression of cyclin E is a characteristic feature of mouse embryonic stem cells (mESCs). We studied the 5′ regulatory region of Cyclin E, also known as Ccne1, and identified binding sites for transcription factors of the naïve pluripotency network, including Esrrb, Klf4, and Tfcp2l1 within 1 kilobase upstream of the transcription start site. Luciferase assay and chromatin immunoprecipitation-quantitative polymerase chain reaction (ChiP–qPCR) study highlighted one binding site for Esrrb that is essential to transcriptional activity of the promoter region, and three binding sites for Klf4 and Tfcp2l1. Knockdown of Esrrb, Klf4, and Tfcp2l1 reduced Cyclin E expression whereas overexpression of Esrrb and Klf4 increased it, indicating a strong correlation between the expression level of these factors and that of cyclin E. We observed that cyclin E overexpression delays differentiation induced by Esrrb depletion, suggesting that cyclin E is an important target of Esrrb for differentiation blockade. We observed that mESCs express a low level of miR-15a and that transfection of a miR-15a mimic decreases Cyclin E mRNA level. These results lead to the conclusion that the high expression level of Cyclin E in mESCs can be attributed to transcriptional activation by Esrrb as well as to the absence of its negative regulator, miR-15a.

Down-regulation of CCNE1 expression suppresses cell proliferation and sensitizes gastric carcinoma cells to Cisplatin

A novel oncogene CCNE1 (cyclin E) is considered to be associated with the development of various tumor types, its role in gastric carcinoma (GC) is little studied and the effect of CCNE1 on chemotherapy also remains unclear. We recruited 55 cases of GC tissues and corresponding normal tissues. Immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR) and Western blot analysis were performed to detect the expression of CCNE1. We also examined the expression of CCNE1 in gastric mucosal GES-1 cells and five GC cell lines. Silencing CCNE1 was used to assess its effect on proliferation and cell cycle in MGC-803 and NCI-N87 cells, as performed by Cell counting kit-8 (CCK-8) and flow cytometry assay. Meanwhile, cell cycle related genes were also detected through qRT-PCR and Western blot. The results showed CCNE1 up-regulation mainly expressed in GC tissues and GC cell lines, also was associated with tumor node metastasis (TNM) stage and lymphatic invasion. Three-year survival curve analysis showed CCNE1 with high expression had a poor prognosis. Silencing CCNE1 significantly reduced cell viability in 48 h, cultured and arrested cell cycle in G₁ phase, moreover, Cyclin A, D1 and C-myc all revealed down-regulation in both MGC-803 and NCI-N87 cells. CCNE1 expression was significantly increased at low and moderate concentrations of Cisplatin. Down-regulation of CCNE1 expression would remarkably promote cell apoptosis induced by Cisplatin, and regulate the rate of Bax/Bcl-2. Down-regulation of CCNE1 expression could inhibit cell proliferation and enhance GC cells sensibility to Cisplatin, possibly involving the regulation of Bcl-2 family.

FTO regulates adipogenesis by controlling cell cycle progression via m6A-YTHDF2 dependent mechanism

N⁶-methyladenosine (m⁶A) is the most prevalent internal mRNA modification in eukaryotes. Loss of m⁶A demethylase FTO increases m⁶A levels and inhibits adipogenesis of preadipocytes. However, its underlying mechanism remains elusive. Here, we demonstrated that silencing FTO inhibited adipogenesis of preadipocytes through impairing cell cycle progression at the early stage of adipogenesis. FTO knockdown markedly decreased the expression of CCNA2 and CDK2, crucial cell cycle regulators, leading to delayed entry of MDI-induced cells into G2 phase. Furthermore, the m⁶A levels of CCNA2 and CDK2 mRNA were significantly upregulated following FTO knockdown. m⁶A-binding protein YTHDF2 recognized and decayed methylated mRNAs of CCNA2 and CDK2, leading to decreased protein expression, thereby prolonging cell cycle progression and suppressing adipogenesis. Our work unravels that FTO regulates adipogenesis by controlling cell cycle progression in an m⁶A-YTHDF2 dependent manner, which provides insights into critical roles of m⁶A methylation in adipogenesis.

RGNNV-induced cell cycle arrest at G1/S phase enhanced viral replication via p53-dependent pathway in GS cells

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Infection of RGNNV redistributed NPM1, stabilized p53 and inhibited cell proliferation by inducing G1 arrest.

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Infection of RGNNV activated p53-dependent pathway, resulting in G1/S phase cell cycle arrest in host cells and directly impacting viral replication.

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NPM1 knockdown could abrogate RGNNV-induced cell proliferation inhibition and cell cycle arrest.

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Our results revealed that RGNNV infection could perturb the progression of cell cycle via the NPM1-p53 pathway and facilitate virus gene replication.

Nervous necrosis virus (NNV) is a ubiquitous pathogen in the aquaculture worldwide. Little is known about the relationship between NNV virus and host cells. Our studies showed that RGNNV infection could induce cell cycle arrest via activation of p53 signaling in cultured host cells. Infection of RGNNV redistributed NPM1, stabilized p53 and inhibited cell proliferation by inducing G1 arrest. RGNNV infection also led to phosphorylation and accumulation of p53 in a time-dependent manner. Furthermore, RGNNV infection upregulated cyclin-dependent kinase inhibitor 1 A (p21) and downregulated cyclin E and cyclin-dependent kinase 2 (CDK2). The expression of genes in the p53 pathway did not change significantly after p53 knockdown by pifithrin-α during RGNNV infection. However, NPM1 knockdown could abrogate RGNNV-induced cell proliferation inhibition, activation of p53 signaling and cell cycle arrest. In addition, RGNNV infection of the cells synchronized in various stages of cell cycle showed that viral genomic RNA and virus titer were higher in the cells released from G1 phase- or S phase-synchronized cells than that in the cells released from the G2 phase-synchronized or asynchronous cells after 18 h p.i. Therefore, our study reveals that RGNNV infection induces the p53-dependent pathway, resulting in a cell cycle arrest at G1 phase in host cells, which might provide a favorable condition for viral replication.

Transcriptomics provides mechanistic indicators of mixture toxicology for IMX-101 and IMX-104 formulations in fathead minnows (Pimephales promelas)

Within the US military, new insensitive munitions (IMs) are rapidly replacing conventional munitions improving safety from unintended detonation. Toxicity data for IM chemicals are expanding rapidly, however IM constituents are typically deployed in mixture formulations, and very little is known about their mixture toxicology. In the present study we sought to characterize the mixture effects and toxicology of the two predominant IM formulations IMX-101 and IMX-104 in acute (48 h) larval fathead minnow (Pimephales promelas) exposures. IMX-101 consists of a mixture of 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine (NQ) while IMX-104 is composed of DNAN, NTO, and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). DNAN was the most potent constituent in IMX-101 eliciting an LC50 of 36.1 mg/L, whereas NTO and NQ did not elicit significant mortality in exposures up to 1040 and 2640 mg/L, respectively. Toxic unit calculations indicated that IMX-101 elicited toxicity representative of the component concentration of DNAN within the mixture. Toxicogenomic responses for the individual constituents of IMX-101 indicated unique transcriptional expression and functional responses characteristic of: oxidative stress, impaired energy metabolism, tissue damage and inflammatory responses in DNAN exposures; impaired steroid biosynthesis and developmental cell-signaling in NQ exposures; and altered mitogen-activated protein kinase signaling in NTO exposures. Transcriptional responses to the IMX-101 mixture were driven by the effects of DNAN where expression and functional responses were nearly identical comparing DNAN alone versus the fractional equivalent of DNAN within IMX-101. Given that each individual constituent of the IMX-101 mixture elicited unique functional responses, and NTO and NQ did not interact with DNAN within the IMX-101 mixture exposure, the overall toxicity and toxicogenomic responses within acute exposures to the IMX-101 formulation are indicative of "independent" mixture toxicology. Alternatively, in the IMX-104 exposure both DNAN and RDX were each present at concentrations sufficient to elicit lethality (RDX LC50 = 28.9 mg/L). Toxic-unit calculations for IMX-104 mixture formulation exposures indicated slight synergistic toxicity (ΣTU LC50 = 0.82, 95% confidence interval = 0.73-0.90). Unique functional responses relative to DNAN were observed in the IMX-104 exposure including responses characteristic of RDX exposure. Based on previous transcriptomics responses to acute RDX exposures in fathead minnow larvae, we hypothesize that the potentially synergistic responses within the IMX-104 mixture are related to interactive effects of each DNAN and RDX on oxidative stress mitigation pathways.

Epigallocatechin gallate targets FTO and inhibits adipogenesis in an mRNA m6A-YTHDF2-dependent manner

BACKGROUND/OBJECTIVE

N⁶-methyladenosine (m⁶A) modification of mRNA plays a role in regulating adipogenesis. However, its underlying mechanism remains largely unknown. Epigallocatechin gallate (EGCG), the most abundant catechin in green tea, plays a critical role in anti-obesity and anti-adipogenesis.

METHODS

High-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HPLC-QqQ-MS/MS) was performed to determine the m⁶A levels in 3T3-L1 preadipocytes. The effects of EGCG on the m⁶A levels in specific genes were determined by methylated RNA immunoprecipitation coupled with quantitative real-time PCR (meRIP-qPCR). Several adipogenesis makers and cell cycle genes were analyzed by quantitative real-time PCR (qPCR) and western blotting. Lipid accumulation was evaluated by oil red O staining. All measurements were performed at least for three times.

RESULTS

Here we showed that EGCG inhibited adipogenesis by blocking the mitotic clonal expansion (MCE) at the early stage of adipocyte differentiation. Exposing 3T3-L1 cells to EGCG reduced the expression of fat mass and obesity-associated (FTO) protein, an m⁶A demethylase, which led to increased overall levels of RNA m⁶A methylation. Cyclin A2 (CCNA2) and cyclin dependent kinase 2 (CDK2) play vital roles in MCE. The m⁶A levels of CCNA2 and CDK2 mRNA were dramatically enhanced by EGCG. Interestingly, EGCG increased the expression of YTH N⁶-methyladenosine RNA binding protein 2 (YTHDF2), which recognized and decayed methylated mRNAs, resulting in decreased protein levels of CCNA2 and CDK2. As a result, MCE was blocked and adipogenesis was inhibited. FTO overexpression and YTHDF2 knockdown in 3T3-L1 cells significantly increased CCNA2 and CDK2 protein levels and ameliorated the EGCG-induced adipogenesis inhibition. Thus, m⁶A-dependent CCNA2 and CDK2 expressions mediated by FTO and YTHDF2 contributed to EGCG-induced adipogenesis inhibition.

CONCLUSION

Our findings provide mechanistic insights into how m⁶A is involved in the EGCG regulation of adipogenesis and shed light on its anti-obesity effect.

SALL2 represses cyclins D1 and E1 expression and restrains G1/S cell cycle transition and cancer-related phenotypes

SALL2 is a poorly characterized transcription factor that belongs to the Spalt‐like family involved in development. Mutations on SALL2 have been associated with ocular coloboma and cancer. In cancers, SALL2 is deregulated and is proposed as a tumor suppressor in ovarian cancer. SALL2 has been implicated in stemness, cell death, proliferation, and quiescence. However, mechanisms underlying roles of SALL2 related to cancer remain largely unknown. Here, we investigated the role of SALL2 in cell proliferation using mouse embryo fibroblasts (MEFs) derived from Sall2^−/− mice. Compared to Sall2^+/+ MEFs, Sall2^−/− MEFs exhibit enhanced cell proliferation and faster postmitotic progression through G1 and S phases. Accordingly, Sall2^−/− MEFs exhibit higher mRNA and protein levels of cyclins D1 and E1. Chromatin immunoprecipitation and promoter reporter assays showed that SALL2 binds and represses CCND1 and CCNE1 promoters, identifying a novel mechanism by which SALL2 may control cell cycle. In addition, the analysis of tissues from Sall2^+/+ and Sall2^−/− mice confirmed the inverse correlation between expression of SALL2 and G1‐S cyclins. Consistent with an antiproliferative function of SALL2, immortalized Sall2^−/− MEFs showed enhanced growth rate, foci formation, and anchorage‐independent growth, confirming tumor suppressor properties for SALL2. Finally, cancer data analyses show negative correlations between SALL2 and G1‐S cyclins’ mRNA levels in several cancers. Altogether, our results demonstrated that SALL2 is a negative regulator of cell proliferation, an effect mediated in part by repression of G1‐S cyclins’ expression. Our results have implications for the understanding and significance of SALL2 role under physiological and pathological conditions.

Identification of differentially expressed genes and biological pathways in bladder cancer

The purpose of the present study was to identify key genes and investigate the related molecular mechanisms of bladder cancer (BC) progression. From the Gene Expression Omnibus database, the gene expression dataset GSE7476 was downloaded, which contained 43 BC samples and 12 normal bladder tissues. GSE7476 was analyzed to screen the differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed for the DEGs using the DAVID database, and a protein-protein interaction (PPI) network was then constructed using Cytoscape software. The results of the GO analysis showed that the upregulated DEGs were significantly enriched in cell division, nucleoplasm and protein binding, while the downregulated DEGs were significantly enriched in ‘extracellular matrix organization’, ‘proteinaceous extracellular matrix’ and ‘heparin binding’. The results of the KEGG pathway analysis showed that the upregulated DEGs were significantly enriched in the ‘cell cycle’, whereas the downregulated DEGs were significantly enriched in ‘complement and coagulation cascades’. JUN, cyclin-dependent kinase 1, FOS, PCNA, TOP2A, CCND1 and CDH1 were found to be hub genes in the PPI network. Sub-networks revealed that these gene were enriched in significant pathways, including the ‘cell cycle’ signaling pathway and ‘PI3K-Akt signaling pathway’. In summary, the present study identified DEGs and key target genes in the progression of BC, providing potential molecular targets and diagnostic biomarkers for the treatment of BC.

Overexpression of LBH is associated with poor prognosis in human hepatocellular carcinoma

Purpose

Limb-bud and heart (LBH) levels are correlated with adverse survival in several malignancies; however, their significance in hepatocellular carcinoma (HCC) remains unclear. The objective of this study was to determine the association between LBH status and clinical outcomes.

Methods

We selected 226 patients with HCC who were treated surgically between 2003 and 2010 at a single academic center. Immunohistochemistry (IHC) was used to detect the protein expression of LBH in HCC samples. Receiver operating characteristic (ROC) curve analysis, Spearman’s rank correlation, Kaplan–Meier plots, and the Cox proportional hazards regression model were used to analyze the data.

Results

A high expression of LBH was detected in 20 (8.8%) of 226 HCC samples. Correlation analysis demonstrated that LBH in HCC was significantly correlated with aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels and clinical stages (P<0.05). In the Kaplan–Meier analysis, the mean survival time of patients with low levels of LBH was longer than that for those with high levels of LBH (P<0.05). The 3-year overall survival rate was 20% for patients with HCC and high levels of LBH versus 67% for patients with HCC and low levels of LBH. In the multivariate analysis, AST/ALT level, clinical stage, tumor relapse, and the level of LBH were the independent prognostic factors for overall survival (P<0.05).

Conclusion

Overexpression of LBH might contribute to the development and progression of HCC. LBH could be a novel prognostic marker for HCC.

GSK3β-dependent cyclin D1 and cyclin E1 degradation is indispensable for NVP-BEZ235 induced G0/G1 arrest in neuroblastoma cells

Cyclin D1 and cyclin E1, as vital regulatory factors of G1-S phase cell cycle progression, are frequently constitutive expressed and associated with pathogenesis and tumorigenesis in most human cancers and they have been regarded as promising targets for cancer therapy. In this study, we established NVP-BEZ235, a potent dual kinase inhibitor, could induce neuroblastoma cells proliferation inhibition without apoptosis activation. Moreover, we showed NVP-BEZ235 could induce neuroblastoma cells arrested at G0/G1 phase accompanied with significant reduction of the cyclin D1 and E1 proteins in a dose dependent manner at nanomole concentration. Additionally we found that GSK3β was dephosphorylated and activated by NVP-BEZ235 and then triggered cyclin D1 and cyclin E1 degradation through ubiquitination proteasome pathway, based on the evidences that NVP-BEZ235 induced downregulation of cyclin D1 and cyclin E1 were obviously recovered by proteasome inhibitor and the blockade of GSK3β contributed to remarkable rescue of cyclin D1 and cyclin E1. Analogous results about its anti-proliferation effects and molecular mechanism were observed on neuroblastoma xenograft mouse model in vivo. Therefore, these results indicate that NVP-BEZ235-induced cyclin D1 and cyclin E1 degradation, which happened through activating GSK3β, and GSK3β-dependent down-regulation of cyclin D1 and cyclin E1 should be available for anticancer therapeutics.

CCNE1 expression in high grade serous carcinoma does not correlate with chemoresistance

Delayed diagnosis of ovarian cancer, as well as high recurrence rates and lack of personalized therapy options, are among the causes for poor survival figures. Much effort is made towards developing new therapeutic possibilities, however predictive biomarkers are still unavailable. CCNE1 amplification, occurring in ∼20% of the high grade serous ovarian tumors, was previously proposed as a marker for platinum resistance and poor prognosis as well as for CDK2 inhibition. The current study aimed to examine the role of CCNE1 positive-immunostain as a predictor of first-line taxane-platinum chemoresistance. We evaluated matched pre- vs. post-neoadjuvant chemotherapy tumor samples and correlated the degree of pathological response to treatment with CCNE1 expression levels. Our results indicate that CCNE1 immunohistochemistry does not predict taxane-platinum chemoresistance in ovarian cancer patients. Further research is required in order to enable personalized adjuvant treatment, in cases where poor pathological response is achieved after the neoadjuvant phase.

Small interfering RNA against ERK1/2 attenuates cigarette smoke-induced pulmonary vascular remodeling

Cigarette smoke may contribute to pulmonary vascular remodeling (PVR), a result of the proliferation of pulmonary artery smooth muscle cells (PASMCs), before pulmonary hypertension in chronic obstructive pulmonary disease (COPD). Activated extracellular signal-regulated kinases 1 and 2 (ERK1/2) are considered to be involved the process of PVR. This study investigated the potential role of ERK1/2 in the proliferation of rat PASMCs (rPASMCs) and cigarette smoke-induced PVR in rats. A small interfering RNA (siRNA) against ERK1/2 (ERK1/2-siRNA) was synthesized, and it significantly reduced the expression of ERK1/2 and cyclin E1, significantly increased the proportion of cells arrested at G0/G1 phase and significantly suppressed the proliferation of rPASMCs treated with cigarette smoke extract compared with controls (all P<0.05). In rats, ERK1/2-siRNA, which was administered intranasally, also inhibited the activation of ERK1/2 and the upregulation of cyclin E1, both of which were induced after the rats were exposed to cigarette smoke for 3 months. ERK1/2-siRNA also significantly reduced PVR (observed by vessel wall thickness and the proportion of fully muscularized vessels) in cigarette smoke-exposed rats compared with a negative control siRNA (P<0.05). Collectively, these data indicated that ERK1/2-siRNA could attenuate PVR in cigarette smoke-exposed rats, and it may have therapeutic value in the treatment of COPD.

Classical swine fever virus Shimen infection increases p53 signaling to promote cell cycle arrest in porcine alveolar macrophages

Classical swine fever virus (CSFV) replicates in macrophages and causes persistent infection. Despite its role in disastrous economic losses in swine industries, the molecular mechanisms underlying its pathogenesis are poorly understood. The virus evades the neutralizing immune response, subverting the immune system to ensure its own survival and persistence. Our genome-wide analysis of porcine alveolar macrophage transcriptional responses to CSFV Shimen infection using the Solexa/Illumina digital gene expression system revealed that p53 pathway components and cell cycle molecules were differentially regulated during infection compared to controls. Further, we investigated the molecular changes in macrophages infected with CSFV Shimen, focusing on the genes involved in the p53 pathway. CSFV Shimen infection led to phosphorylation and accumulation of p53 in a time-dependent manner. Furthermore, CSFV Shimen infection upregulated cyclin-dependent kinase inhibitor 1A (p21) mRNA and protein. In addition, CSFV Shimen infection induced cell cycle arrest at the G1 phase, as well as downregulation of cyclin E1 and cyclin-dependent kinase 2 (CDK2). The expression of genes in the p53 pathway did not change significantly after p53 knockdown by pifithrin-α during CSFV Shimen infection. Our data suggest that CSFV Shimen infection increases expression of host p53 and p21, and inhibits expression of cyclin E1 and CDK2, leading to cell cycle arrest at the G1 phase. CSFV may utilize this strategy to subvert the innate immune response and proliferate in host cells.

Identification of Predictive DNA Methylation Biomarkers for Chemotherapy Response in Colorectal Cancer

Resistance to 5-Fluorouracil (5-FU) is a major obstacle to the successful treatment of colorectal cancer (CRC) and posed an increased risk of recurrence. DNA methylation has been suggested as one of the underlying mechanisms for recurrent disease and its contribution to the development of drug resistance remains to be clarified. This study aimed to determine the methylation phenotype in CRC for identification of predictive markers for chemotherapy response. We performed DNA methylation profiling on 43 non-recurrent and five recurrent CRC patients using the Illumina Infinium HumanMethylation450 Beadchip assay. In addition, CRC cells with different genetic backgrounds, response to 5-FU and global methylation levels (HT29 and SW48) were treated with 5-FU and DNA methylation inhibitor 5-aza-2′-deoxycytidine (5-azadC). The singular and combined effects of these two drug classes on cell viability and global methylation profiles were investigated. Our genome-wide methylation study on the clinical specimens showed that recurrent CRCs exhibited higher methylation levels compared to non-recurrent CRCs. We identified 4787 significantly differentially methylated genes (P < 0.05); 3112 genes were hyper- while 1675 genes were hypomethylated in the recurrent group compared to the non-recurrent. Fifty eight and 47 of the significantly hypermethylated and hypomethylated genes have an absolute recurrent/non-recurrent methylation difference of ≥20%. Most of the hypermethylated genes were involved in the MAPK signaling pathway which is a key regulator for apoptosis while the hypomethylated genes were involved in the PI3K-AKT signaling pathway and proliferation process. We also demonstrate that 5-azadC treatment enhanced response to 5-FU which resulted in significant growth inhibition compared to 5-FU alone in hypermethylated cell lines SW48. In conclusion, we found the evidence of five potentially biologically important genes in recurrent CRCs that could possibly serve as a new potential therapeutic targets for patients with chemoresistance. We postulate that aberrant methylation of CCNEI, CCNDBP1, PON3, DDX43, and CHL1 in CRC might be associated with the recurrence of CRC and 5-azadC-mediated restoration of 5-FU sensitivity is mediated at least in part by MAPK signaling pathway.