The clinical significance of CDK1 expression in oral squamous cell carcinoma

Targeting the USP7-CDK1 axis suppresses estrogen receptor-positive breast cancer progression

Estrogen receptor-positive breast cancer (ERPBC) accounts for approximately 70% of breast cancers in women worldwide. The therapeutic strategy process for ERPBC is well-established and significantly reduces the mortality rate. The discovery of new therapeutic targets remains essential for ERPBC patients with metastasis or endocrine resistance. This study indicated that USP7 is highly expressed in ERBPC and promotes tumor progression and metastasis. Inhibition of USP7 activity repressed proliferation, induced apoptosis, suppressed migration and invasive activities, and reversed the epithelial-mesenchymal transition of ERPBC. Mass spectrometry analysis indicated that USP7 regulates CDK1 expression, which is highly expressed and correlates with a poor overall survival rate in ERPBC. USP7 directly interacts with CDK1 and regulates its stability. The combined inhibition of USP7 and CDK1 by GNE-6776 and Ro-3306 synergistically represses the malignant process and metastasis of ERPBC. These findings proved that targeting USP7 and CDK1 is a potential strategy for overcoming endocrine resistance in patients with advanced ERPBC.

The antitumor peptide M1-20 induced the degradation of CDK1 through CUL4-DDB1-DCAF1-involved ubiquitination

CDK1 is an oncogenic serine/threonine kinase known to play an important role in the regulation of the cell cycle. FOXM1, as one of the CDK1 substrates, requires binding of CDK1/CCNB1 complex for phosphorylation-dependent recruitment of p300/CBP coactivators to mediate transcriptional activity. Previous studies from our laboratory found that a novel peptide (M1-20) derived from the C-terminus of FOXM1 exhibited potent inhibitory effects for cancer cells. Based on these proofs and to explore the inhibitory mechanism of M1-20, we designed experiments and found that CDK1 served as an important target of M1-20. M1-20 enhanced the ubiquitination and degradation of CDK1 by CUL4-DDB1-DCAF1 complexes through the proteasome pathway. M1-20 could also affect the formation of CDK1/CCNB1 complexes. In addition, compared to RO3306, a CDK1 inhibitor, M1-20 exhibited excellent inhibitory effects in FVB/N MMTV-PyVT murine model of spontaneous breast cancer. These results suggested that M1-20 was a potential CDK1 inhibitor for the treatment of cancer.

CDK1 and CCNA2 play important roles in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a malignant tumor that occurs in oral cavity and is dominated by squamous cells. The relationship between CDK1, CCNA2, and OSCC is still unclear. The OSCC datasets GSE74530 and GSE85195 configuration files were downloaded from the Gene Expression Omnibus (GEO) database and were derived from platforms GPL570 and GPL6480. Differentially expressed genes (DEGs) were screened. The weighted gene co-expression network analysis, functional enrichment analysis, gene set enrichment analysis, construction and analysis of protein-protein interaction (PPI) network, Comparative Toxicogenomics Database analysis were performed. Gene expression heatmap was drawn. TargetScan was used to screen miRNAs that regulate central DEGs. A total of 1756 DEGs were identified. According to Gene Ontology (GO) analysis, they were predominantly enriched in processes related to organic acid catabolic metabolism, centromeric, and chromosomal region condensation, and oxidoreductase activity. In Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the DEGs were mainly concentrated in metabolic pathways, P53 signaling pathway, and PPAR signaling pathway. Weighted gene co-expression network analysis was performed with a soft-thresholding power set at 9, leading to the identification of 6 core genes (BUB1B, CCNB1, KIF20A, CCNA2, CDCA8, CDK1). The gene expression heatmap revealed that core genes (CDK1, CCNA2) were highly expressed in OSCC samples. Comparative Toxicogenomics Database analysis demonstrated associations between the 6 genes (BUB1B, CCNB1, KIF20A, CCNA2, CDCA8, CDK1) and oral tumors, precancerous lesions, inflammation, immune system disorders, and tongue tumors. The associated miRNAs for CDK1 gene were hsa-miR-203a-3p.2, while for CCNA2 gene, they were hsa-miR-6766-3p, hsa-miR-4782-3p, and hsa-miR-219a-5p. CDK1 and CCNA2 are highly expressed in OSCC. The higher the expression of CDK1 and CCNA2, the worse the prognosis.

Identification of core genes as potential biomarkers for predicting progression and prognosis in glioblastoma

Background: Glioblastoma is a common malignant neuroepithelial neoplasm with poor clinical outcomes and limited treatment options. It is extremely important to search and confirm diverse hub genes that are effective in the advance and prediction of glioblastoma.

Methods: We analyzed GSE50161, GSE4290, and GSE68848, the three microarray datasets retrieved from the GEO database. GO function and KEGG pathway enrichment analyses for differentially expressed genes (DEGs) were performed using DAVID. The PPI network of the DEGs was analyzed using the Search Tool for the Retrieval of Interacting Genes database and visualized by Cytoscape software. Hub genes were identified through the PPI network and a robust rank aggregation method. The Cancer Genome Atlas (TCGA) and the Oncomine database were used to validate the hub genes. In addition, a survival curve analysis was conducted to verify the correlation between the expression of hub genes and patient prognosis. Human glioblastoma cells and normal cells were collected, and then RT-PCR, Western blot, and immunofluorescence were conducted to validate the expression of the NDC80 gene. A cell proliferation assay was used to detect the proliferation of glioma cells. The effects of NDC80 expression on migration and invasion of GBM cell lines were evaluated by conducting scratch and transwell assays.

Results: A total of 716 DEGs were common to all three microarray datasets, which included 188 upregulated DEGs and 528 downregulated DEGs. Furthermore, we found that among the common DEGs, 10 hub genes showed a high degree of connectivity. The expression of the 10 hub genes in TCGA and the Oncomine database was significantly overexpressed in glioblastoma compared with normal genes. Additionally, the survival analysis showed that the patients with low expression of six genes (BIR5C, CDC20, NDC80, CDK1, TOP2A, and MELK) had a significantly favorable prognosis (p < 0.01). We discovered that NDC80, which has been shown to be important in other cancers, also has an important role in malignant gliomas. The RT-PCR, Western blot, and immunofluorescence results showed that the expression level of NDC80 was significantly higher in human glioblastoma cells than in normal cells. Moreover, we identified that NDC80 increased the proliferation and invasion abilities of human glioblastoma cells.

Conclusion: The six genes identified here may be utilized to form a panel of disease progression and predictive biomarkers of glioblastoma for clinical purposes. NDC80, one of the six genes, was discovered to have a potentially important role in GBM, a finding that needs to be further studied.

Prognostic significance of BLK expression in R-CHOP treated diffuse large B-cell lymphoma

Background

The aim of the present study was to evaluate the prognostic significance of B-cell lymphocyte kinase (BLK) expression for survival outcomes in diffuse large B-cell lymphoma (DLBCL) patients treated with R-CHOP.

Methods

We retrospectively analyzed the medical records of 89 patients from two tertiary referral hospitals. The expression of BLK, SYK, and CDK1 were evaluated in a semi-quantitative method using an H-score, and the proportions of BCL2 and C-MYC were evaluated.

Results

A total of 89 patients received R-CHOP chemotherapy as a first-line chemotherapy. The expression rates of BLK in tumor cells was 39.2% (n = 34). BLK expression status was not significantly associated with clinical variables; however, BLK expression in tumor cells was significantly associated with the expression of both C-MYC and BCL2 (p = .003). With a median follow-up of 60.4 months, patients with BLK expression had significantly lower 5-year progression-free survival (PFS) and overall survival rates (49.8% and 60.9%, respectively) than patients without BLK expression (77.3% and 86.7%, respectively). In multivariate analysis for PFS, BLK positivity was an independent poor prognostic factor (hazard ratio, 2.208; p = .040).

Conclusions

Here, we describe the clinicopathological features and survival outcome according to expression of BLK in DLBCL. Approximately 39% of DLBCL patients showed BLK positivity, which was associated as a predictive marker for poor prognosis in patients who received R-CHOP chemotherapy.

Role of Molecular Targeted Therapeutic Drugs in Treatment of Oral Squamous Cell Carcinoma: Development and Current Strategies—A Review Article

Because of active advancement in the field of biomedicine, people have in-depth knowledge of biological nature of malignant tumors and are able to recognized the overexpression of different molecules such as vascular endothelial growth factor receptor, cyclin-dependent kinase, and programmed cell death receptor. Presently, various targeted therapeutic drugs are used in different clinical trials in those patients suffering from oral squamous cell carcinoma. In this review, we converse about the various targeted therapeutic drugs and their advancement in the treatment of oral squamous cell carcinoma. This review scrutinizes the existing documentation in the literature related to the targeted therapies for oral squamous cell carcinoma. English language articles were searched in various databases such as PubMed, Scopus, Science Direct, and Google Scholar. The keywords used for searching are “oral squamous cell carcinoma,” “targeted therapy,” and “therapeutic drugs.”

CDK1 Promotes Epithelial–Mesenchymal Transition and Migration of Head and Neck Squamous Carcinoma Cells by Repressing ∆Np63α-Mediated Transcriptional Regulation

∆Np63α is a key transcription factor overexpressed in types of squamous cell carcinomas (SCCs), which represses epithelial–mesenchymal transition (EMT) and cell migration. In this study, we found that CDK1 phosphorylates ∆Np63α at the T123 site, impairing its affinity to the target promoters of its downstream genes and its regulation of them in turn. Database analysis revealed that CDK1 is overexpressed in head and neck squamous cell carcinomas (HNSCCs), especially the metastatic HNSCCs, and is negatively correlated with overall survival. We further found that CDK1 promotes the EMT and migration of HNSCC cells by inhibiting ∆Np63α. Altogether, our study identified CDK1 as a novel regulator of ΔNp63α, which can modulate EMT and cell migration in HNSCCs. Our findings will help to elucidate the migration mechanism of HNSCC cells.

Proliferation and Apoptosis Pathways and Factors in Oral Squamous Cell Carcinoma

Oral cancer is the most common form of head and neck squamous cell carcinoma (HNSCC) and most frequently presents as oral squamous cell carcinoma (OSCC), which is associated with an alarmingly high mortality rate. Internationally, a plethora of research to further our understanding of the molecular pathways related to oral cancer is performed. This research is of value for early diagnosis, prognosis, and the investigation of new drugs that can ameliorate the harmful effects of oral cancer and provide optimal patient outcomes with minimal long-term complications. Two pathways on which the progression of OSCC depends on are those of proliferation and apoptosis, which overlap at many junctions. Herein, we aim to review these pathways and factors related to OSCC progression. Publicly available search engines, PubMed and Google Scholar, were used with the following keywords to identify relevant literature: oral cancer, proliferation, proliferation factors, genes, mutations, and tumor suppressor. We anticipate that the use of information provided through this review will further progress translational cancer research work in the field of oral cancer.

Novel Therapies for Tongue Squamous Cell Carcinoma Patients with High-Grade Tumors

BACKGROUND

Tongue squamous cell carcinoma (TSCC) patients with high-grade tumors usually suffer from high occurrence and poor prognosis. The current study aimed at finding the biomarkers related to tumor grades and proposing potential therapies by these biomarkers.

METHODS

The mRNA expression matrix of TSCC samples from The Cancer Genome Atlas (TCGA) database was analyzed to identify hub proteins related to tumor grades. The mRNA expression patterns of these hub proteins between TSCC and adjacent control samples were validated in three independent TSCC data sets (i.e., GSE9844, GSE30784, and GSE13601). The correlation between cell cycle index and immunotherapy efficacy was tested on the IMvigor210 data set. Based on the structure of hub proteins, virtual screening was applied to compounds to find the potential inhibitors.

RESULTS

A total of six cell cycle biomarkers (i.e., BUB1, CCNB2, CDC6, CDC20, CDK1, and MCM2) were selected as hub proteins by protein-protein interaction (PPI) analysis. In the validation data sets, the mRNA expression levels of these hub proteins were higher in tumor samples versus normal controls. The cell cycle index was constructed by the mRNA expression levels of these hub proteins, and patients with a high cell cycle index demonstrated favorable drug response to the immunotherapy. Three small molecules (i.e., ZINC100052685, ZINC8214703, and ZINC85537014) were found to bind with hub proteins and selected as drug candidates.

CONCLUSION

The cell cycle index might provide a novel reference for selecting appropriate cancer patient candidates for immunotherapy. The current research might contribute to the development of precision medicine and improve the prognosis of TSCC.

Molecular docking analysis of CDK-1 inhibitors from Chrysophyllum cainito leaves

It is of interest to document the molecular docking analysis of Cyclin-dependent kinase 1 (CDK-1) inhibitors from Chrysophyllum cainito leaves towards the treatment of tumors using the known structure of PDB ID: 5HQ0. Data shows that molecules such as 8- (Dimethylamino)-7-(3-(4-ethylphenoxy)-2d, ethyl 6-oxo-5-propylheptanoate, 2,3-dihydro-3, 5-dihydroxy-6-methyl-4h-pyran-4-one, 1,2,3-benzenetriol and 1,4-benzenediol 2,5-bis (1,1-dimethylethyl) identified in methanolic extract of C. cainito have binding features with CDK1 for further consideration.

Endometriosis Cell Proliferation Induced by Bone Marrow Mesenchymal Stem Cells

Endometriosis is an estrogen-dependent gynecological disorder that affects 10% of reproductive-aged women and causes pelvic pain and infertility. Bone marrow-derived stem cells (BMDCs) are known to engraft endometriosis in association with lesion growth; however, they do not undergo significant clonal expansion. The indirect effects of BMDCs on endometriosis growth and cell proliferation are not well characterized. Here, we demonstrate that BMDCs' co-culture increased endometrial stromal cell proliferation. In vitro studies using endometrial cells showed that BMDCs increased cell proliferation and activation of CDK1 in both an endometriosis cell line and primary endometrial stromal cells from women with endometriosis, however not in normal endometrial cells. In vivo studies using a mouse model of endometriosis showed increased CDK1+ expression associated with engrafted GFP + BMDCs. These results suggest that endometrial cell proliferation is induced by stem cell-derived trophic factors leading to the growth of endometriotic lesions. Targeting the specific signaling molecules secreted by BMDC may lead to novel therapeutic strategies for controlling cell proliferation in endometriosis.

Identification of CDK1 as a candidate marker in cutaneous squamous cell carcinoma by integrated bioinformatics analysis

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is a relatively common cancer that accounts for nearly 50% of non-melanoma skin cancer cases. However, the genotypes that are linked with poor prognosis and/or high relapse rates and pathogenic mechanisms of cSCC are not fully understood. To address these points, three gene expression datasets were analyzed to identify candidate biomarker genes in cSCC.

METHODS

The GSE117247, GSE32979, and GSE98767 datasets comprising a total of 32 cSCC samples and 31 normal skin tissue samples were obtained from the National Center for Biotechnology Information Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified and underwent pathway enrichment analyses with the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG). A putative DEG protein-protein interaction (PPI) network was also established that included hub genes. The expression of CDK1, MAD2L1, BUB1 ans CDC20 were examined in the study.

RESULTS

A total of 335 genes were identified, encompassing 219 found to be upregulated and 116 genes that were downregulated in cSCC, compared to normal tissue. Enriched functions of these DEGs were associated with Ephrin receptor signaling and cell division; cytosol, membrane, and extracellular exosomes; ATP-, poly(A) RNA-, and identical protein binding. We also established a PPI network comprising 332 nodes and identified KIF2C, CDC42, AURKA, MAD2L1, MYC, CDK1, FEN1, H2AFZ, BUB1, BUB1B, CKS2, CDC20, CCT2, ACTR2, ACTB, MAPK14, and HDAC1 as candidate hub genes. The expression of CDK1 are significantly higher in the cSCC tissues than that in normal skin.

CONCLUSIONS

The DEGs identified in this study are potential therapeutic targets and biomarkers for cSCC. CDK1 is a gene closely related to the occurrence and development of cSCC, which may play an important role. Bioinformatics analysis shows that it is involved in the important pathway of the pathogenesis of cSCC, and may be recognized and applied as a new biomarker in the future diagnosis and treatment of cSCC.

Integrated assessment of CDK1 upregulation in thyroid cancer

Cyclin-dependent kinase 1 (CDK1) has a unique role in cell cycle regulation, as it is crucial for cell cycle progression and cell division. The aim of the present study was to use a combination of various detection methods to examine the expression and clinical significance of CDK1 in thyroid cancer (THCA). We used in-house tissue microarrays, immunohistochemistry, public RNA-sequencing, gene microarrays, and meta-analyses to conduct a comprehensive analysis of the role of CDK1 in the occurrence and development of THCA. CDK1 protein expression was notably higher in THCA tissues than in non-cancer tissues as evidenced by the in-house tissue microarrays. The expression of CDK1 protein was also significantly higher in pathologic T3-T4 than in T1-T2 samples. The pooled standardized mean difference (SMD) for CDK1 was 0.71 (95% CI, 0.46-0.95) including a total of 931 THCA and 585 non-cancerous thyroid tissue samples. An aggregation of the immunohistochemistry results and the RNA-sequencing/microarray findings gave a pooled SMD for CDK1 expression of 2.13 (95% CI, 1.30-2.96). The final area under curve (AUC) for the summarized receiver operating characteristic (sROC) was 0.7941 using all 1102 cases of THCA and 672 cases of controls. KEGG analysis with the co-expressed genes of CDK1 in THCA demonstrated the top enriched pathways to be the cell cycle, thyroid hormone synthesis, autoimmune thyroid disease, etc. In summary, we reveal the overexpression of CDK1 in THCA based on multiple detection methods that combine independent cohorts. However, further studies are required to elucidate the molecular mechanisms of CDK1 that promotes the biological aggressiveness of THCA cells.

Identification of biomarkers and construction of a microRNA-mRNA regulatory network for ependymoma using integrated bioinformatics analysis

Ependymomas (EPNs) are one of the most common types of malignant neuroepithelial tumors. In an effort to identify potential biomarkers involved in the pathogenesis of EPN, the mRNA expression profiles of the GSE25604, GSE50161, GSE66354, GSE74195 and GSE86574 datasets, in addition to the microRNA (miRNA/miR) expression profiles of GSE42657 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) between EPN and normal brain tissue samples were identified using the Limma package in R and GEO2R, respectively. Functional and pathway enrichment analyses were conducted using the Database for Annotation, Visualization and Integrated Discovery. A protein-protein interaction network was constructed using the Search Tool for Retrieval of Interacting Genes database, which was visualized using Cytoscape. The targeted genes of DEMs were predicted using miRWalk2.0 and a miRNA-mRNA regulatory network was constructed. Following analysis, a total of 948 DEGs and 129 DEMs were identified. Functional enrichment analysis revealed that 609 upregulated DEGs were significantly enriched in ‘PI3K-Akt signaling pathway’, while 339 downregulated DEGs were primarily involved in ‘cell junction’ and ‘retrograde endocannabinoid signaling’. In addition, 6 hub genes [cyclin dependent kinase 1, CD44 molecule (Indian blood group) (CD44), proliferating cell nuclear antigen (PCNA), MYC, synaptotagmin 1 (SYT1) and kinesin family member 4A] and 6 crucial miRNAs [homo sapiens (hsa)-miR-34a-5p, hsa-miR-449a, hsa-miR-106a-5p, hsa-miR-124-3p, hsa-miR-128-3p and hsa-miR-330-3p] were identified as biomarkers and potential therapeutic targets for EPN. Furthermore, a microRNA-mRNA regulatory network was constructed to highlight the interactions between DEMs and their target DEGs; this included the hsa-miR-449a-SYT1, hsa-miR-34a-5p-SYT1, hsa-miR-330-3p-CD44 and hsa-miR-124-3p-PCNA pairs, whose expression levels were confirmed using reverse transcription-quantitative polymerase chain reaction. In conclusion, the present study may provide important data for the investigation of the molecular mechanisms of EPN pathogenesis.

Progress in targeted therapeutic drugs for oral squamous cell carcinoma

With the rapid development of biomedicine, people have a deeper understanding with the biological characteristics of malignant tumors, and begin to notice that in most tumors, there are over-expression of several molecules such as epidermal growth factor receptor(EGFR), vascular endothelial growth factor (VEGF) and its receptors,mammalian target of rapamycin(mTOR),programmed cell death receptor-1(PD-1),cyclin-dependent kinases(CDKs) and so on, whose levels are closely related to the prognosis of tumors. It has been found that the drugs targeting the above molecules can significantly improve the survival rate of cancer patients, and have the advantages of high selectivity, low toxicity and high therapeutic index. Targeted drugs, as new ones in the field of cancer, have achieved good efficacy in most tumor treatments. Oral cancer is an aggressive malignant tumour that is prone to relapse and metastasis. More than 90% of them are squamous cell carcinoma, and the 5-year survival rate remains at about 50%-60%.The proposing of targeted therapy opens up a new way for the treatment of oral cancer and brings dawn to patients with advanced diseases. Currently,a variety of targeted therapeutic drugs are being tested in various clinical trials in patients with oral squamous cell carcinoma(OSCC)·In this paper, we discuss the research progress of targeted therapeutic drugs in the treatment of OSCC in recent years.

KIAA1429 acts as an oncogenic factor in breast cancer by regulating CDK1 in an N6-methyladenosine-independent manner

Most N6-methyladenosine (m⁶A) associated regulatory proteins (i.e., m⁶A writer, eraser, and reader proteins) are involved in the pathogenesis of various cancers, mostly in m⁶A-dependent manners. As a component in the m⁶A 'writers', KIAA1429 is reported to be an RNA-binding protein and involved in the m⁶A modification, mRNA splicing and processing. Till now, the functions of KIAA1429 in tumorigenesis and related mechanism have not been reported. In the present study, we found KIAA1429 was highly expressed in breast cancer tissues, but frequently down-regulated in non-cancerous breast tissues. The overall survival of breast cancer patients with high-expression KIAA1429 was significantly shorter than those with low-expression KIAA1429. Then, we demonstrated that KIAA1429 was associated with breast cancer proliferation and metastasis in vivo and in vitro. The potential targeting genes of KIAA1429 in breast cancer were identified by RNA immunoprecipitation sequencing. One of these genes is cyclin-dependent kinase 1 (CDK1), which plays an oncogenic role in cancers. Furthermore, we confirmed that KIAA1429 played its oncogenic role in breast cancer by regulating CDK1 by an m⁶A-independent manner. 5'-fluorouracil was found to be very effective in reducing the expression of KIAA1429 and CDK1 in breast cancer. These findings indicated that KIAA1429 could promote breast cancer progression and was correlated with pathogenesis. It may represent a promising therapeutic strategy on breast cancer, especially in combination with CDK1 treatment.

The role of cyclin-dependent kinases in oral potentially malignant disorders and oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a major global health problem with a relatively low-moderate 5-year survival rate. OSCC is often preceded by lesions and conditions known as oral potentially malignant disorders (OPMDs) that have an increased risk of malignant transformation. Despite advances in diagnostic technology and cancer research, the prognosis of OSCC remains poor as it is frequently detected a late stage. Understanding the molecular pathways involved in oral carcinogenesis provides a platform to identify biomarkers that may allow the early detection of OSCC and accurate prediction of the malignant potential of OPMDs. In addition, specific molecular inhibitors can be developed to target these important pathways and allow advanced therapeutic management to improve the prognosis of this malignancy. A common feature across a number of different cancers is the dysfunction of cell cycle moderator proteins known as cyclin-dependent kinases. This review summarises the current literature regarding the role of cyclin-dependent kinases in oral carcinogenesis with a particular focus on cyclin-dependent kinases 4 (CDK4) and 6 (CDK6). This is of particular relevance as CDK4 and CDK6 inhibitors have shown some promising results in other cancer types and are interesting potential treatments for OSCC.

Study of the mechanism by which dinaciclib induces apoptosis and cell cycle arrest of lymphoma Raji cells through a CDK1-involved pathway

Objective

This study aimed to identify and evaluate the mechanism by which apoptosis and cell cycle arrest were induced by dinaciclib in lymphoma Raji cells.

Methods

The colony formation assay was used to detect cell proliferation of Raji cells. Cell cycle arrest and cell apoptosis were determined by flow cytometry and TUNEL assays, respectively. Protein expression related to the Raji cell state was evaluated by Western blot. The Raji/Dinaciclib drug‐resistant cell line was established, where the regulating functions of CDK1‐involved pathway were verified. In addition, the effect of dinaciclib in vivo was examined in orthotopically implanted tumors in nude mice.

Results

Cell apoptosis was induced, and DNA synthesis ability was decreased in a time‐dependent manner in dinaciclib‐treated lymphoma Raji cells. Furthermore, the cell cycle was found to be blocked in the G2/M Phase. Further study indicated that CDK1‐involved pathway played a key regulatory role in this process. It was revealed by cell transfection that the expression of cell cycle proteins was downregulated after treatment with dinaciclib through a CDK1‐involved pathway, which eventually led to apoptosis. Knockdown of CDK1 restored the sensitivity of the Raji/Dinaciclib cells to dinaciclib. Xenograft model of nude mice showed that dinaciclib treatment in vivo could effectively inhibit tumor growth, consistent with the experiment results mentioned before.

Conclusion

In this study, we clarified the mechanisms through which dinaciclib induces Raji cell apoptosis and blocks the cell cycle through a CDK1‐involved pathway, which supported that dinaciclib had potential values in the treatment of lymphoma.

Glioma stages prediction based on machine learning algorithm combined with protein-protein interaction networks

BACKGROUND

Glioma is the most lethal nervous system cancer. Recent studies have made great efforts to study the occurrence and development of glioma, but the molecular mechanisms are still unclear. This study was designed to reveal the molecular mechanisms of glioma based on protein-protein interaction network combined with machine learning methods. Key differentially expressed genes (DEGs) were screened and selected by using the protein-protein interaction (PPI) networks.

RESULTS

As a result, 19 genes between grade I and grade II, 21 genes between grade II and grade III, and 20 genes between grade III and grade IV. Then, five machine learning methods were employed to predict the gliomas stages based on the selected key genes. After comparison, Complement Naive Bayes classifier was employed to build the prediction model for grade II-III with accuracy 72.8%. And Random forest was employed to build the prediction model for grade I-II and grade III-VI with accuracy 97.1% and 83.2%, respectively. Finally, the selected genes were analyzed by PPI networks, Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and the results improve our understanding of the biological functions of select DEGs involved in glioma growth. We expect that the key genes expressed have a guiding significance for the occurrence of gliomas or, at the very least, that they are useful for tumor researchers.

CONCLUSION

Machine learning combined with PPI networks, GO and KEGG analyses of selected DEGs improve our understanding of the biological functions involved in glioma growth.

Phosphoproteomic Profiling Identifies Aberrant Activation of Integrin Signaling in Aggressive Non-Type Bladder Carcinoma

Bladder carcinoma is highly heterogeneous and its complex molecular landscape; thus, poses a significant challenge for resolving an effective treatment in metastatic tumors. We computed the epithelial-mesenchymal transition (EMT) scores of three bladder carcinoma subtypes-luminal, basal, and non-type. The EMT score of the non-type indicated a "mesenchymal-like" phenotype, which correlates with a relatively more aggressive form of carcinoma, typified by an increased migration and invasion. To identify the altered signaling pathways potentially regulating this EMT phenotype in bladder cancer cell lines, we utilized liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based phosphoproteomic approach. Bioinformatics analyses were carried out to determine the activated pathways, networks, and functions in bladder carcinoma cell lines. A total of 3125 proteins were identified, with 289 signature proteins noted to be differentially phosphorylated (p ≤ 0.05) in the non-type cell lines. The integrin pathway was significantly enriched and five major proteins (TLN1, CTTN, CRKL, ZYX and BCAR3) regulating cell motility and invasion were hyperphosphorylated. Our study reveals GSK3A/B and CDK1 as promising druggable targets for the non-type molecular subtype, which could improve the treatment outcomes for aggressive bladder carcinoma.

Cyclin-dependent kinase 1 and survivin as potential therapeutic targets against nasal natural killer/T-cell lymphoma

Nasal natural killer/T-cell lymphoma (NNKTL) is closely associated with Epstein-Barr virus (EBV) and is characterized by poor prognosis, resulting from rapid progression of lesions in the affected organs. Recent data have shown that NNKTL is associated with the aberrant expression of cyclin-dependent kinase 1 (CDK1) and its downstream target survivin, but little is known about the functional roles of CDK1 and survivin in NNKTL. In the current study, we show that knockdown of the EBV-encoded oncoprotein latent membrane protein 1 (LMP1) induces downregulation of CDK1 and survivin in NNKTL cells. Immunohistochemistry detected CDK1 and survivin expression in LMP1-positive cells of NNKTL biopsy specimens. Inhibition of CDK1 and survivin in NNKTL cells with several inhibitors led to a dose-dependent decrease in cell proliferation. In addition, the Sp1 inhibitor mithramycin, which can downregulate both CDK1 and survivin, significantly suppressed the growth of established NNKTL in a murine xenograft model. Our results suggest that LMP1 upregulation of CDK1 and survivin may be essential for NNKTL progression. Furthermore, targeting CDK1 and survivin with Sp1 inhibitors such as mithramycin may be an effective approach to treat NNKTL, which is considered to be a treatment-refractory lymphoma.

MiR-378a-5p Regulates Proliferation and Migration in Vascular Smooth Muscle Cell by Targeting CDK1

Objective: Abnormal proliferation or migration of vascular smooth muscle cells (VSMCs) can lead to vessel lesions, resulting in atherosclerosis and in stent-restenosis (IRS). The purpose of our study was to establish the role of miR-378a-5p and its targets in regulating VSMCs function and IRS.

Methods: EdU assays and Cell Counting Kit-8 (CCK-8) assays were applied to evaluate VSMCs proliferation, wound healing assays and transwell assays were applied to assess cells migration. Furthermore, quantitative reverse transcription–polymerase chain reaction (qRT-PCR) was performed to investigate the expression level of miR-378a-5p IRS patients and healthy individuals. Target genes were predicted using Target Scan and miRanda software, and biological functions of candidate genes were explored through bioinformatics analysis. Moreover, RNA-binding protein immunoprecipitation (RIP) was carried out to analyze the miRNAs interactions with proteins. We also used Immunofluorescence (IF) and fluorescence microscopy to determine the binding properties, localization and expression of miR-378a-5p with downstream target CDK1.

Results: The expression of miR-378a-5p was increased in the group with stent restenosis compared with healthy people, as well as in the group which VSMCs stimulated by platelet-derived growth factor-BB (PDGF-BB) compared with NCs. MiR-378a-5p over-expression had significantly promoted proliferative and migratory effects, while miR-378a-5p inhibitor suppressed VSMC proliferation and migration. CDK1 was proved to be the functional target of miR-378a-5p in VSMCs. Encouragingly, the expression of miR-378a-5p was increased in patients with stent restenosis compared with healthy people, as well as in PDGF-BB-stimulated VSMCs compared with control cells. Furthermore, co-transfection experiments demonstrated that miR-378a-5p over-expression promoted proliferation and migration of VSMCs specifically by reducing CDK1 gene expression levels.

Conclusion: In this investigatory, we concluded that miR-378a-5p is a critical mediator in regulating VSMC proliferation and migration by targeting CDK1/p21 signaling pathway. Thereby, interventions aimed at miR-378a-5p may be of therapeutic application in the prevention and treatment of stent restenosis.

Cancer Stem Cell based molecular predictors of tumor recurrence in Oral squamous cell carcinoma

OBJECTIVE

This study aimed to identify the cancer stem cell specific biomarkers that can be effective candidate prognosticators of oral squamous cell carcinoma.

DESIGN

Microarray-based meta-analysis derived transcriptional profile of head and neck cancers was compared with the Cancer Stem Cell database to arrive at a subset of markers. This subset was further co-related with clinico-pathological parameters, recurrence and survival of oral cancer patients (n = 313) in The Cancer Genome Atlas database and in oral cancer (n = 28) patients.

RESULTS

Meta-analysis in combination with database comparison identified a panel of 221 genes specific to head and neck cancers. Correlation of expression levels of these markers in the oral cancer cohort of The Cancer Genome Atlas (n = 313) with treatment outcome identified 54 genes (p < 0.05 or fold change >2) associated with disease recurrence, 8 genes (NQO1, UBE2C, EDNRB, FKBP4, STAT3, HOXA1, RIT1, AURKA) being significant with high fold change. Assessment of the efficacy of the subset (n = 54) as survival predictors identified an additional 4 genes (CDK1, GINS2, PHF5 A, ERBB2) that co-related with poor disease-free survival (p < 0.05). CDK1 showed a significant association with the clinical stage, margin status and with advanced pathological parameters. Initial patient validation indicated that CDK1 and NQO1 significantly co-related with the poor disease-free and overall survival (p < 0.05).

CONCLUSION

This panel of oral cancer specific, cancer stem cell associated markers identified in this study, a subset of which was validated, will be of clinical benefit subject to large scale validation studies.

Identification of the potential oncogenes in glioblastoma based on bioinformatic analysis and elucidation of the underlying mechanisms

Glioblastoma (GBM) is a common malignant tumour in the human brain, but its molecular mechanisms have not been systematically evaluated. The aim of this study was to identify potential key oncogenes associated with the progression of GBM and to elucidate their mechanisms. The gene expression profile of GSE50161, selected from the Gene Expression Omnibus database, was analysed to find cancer-associated genes and gene functions in GBM. In total, 486 differentially expressed genes, including 128 upregulated genes, were identified. The function and pathway enrichment of these genes were analysed through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Survival analysis for three selected partially upregulated genes, CDK1, CCNB1 and CDC20, showed that their high expression was significantly associated with poor survival in GBM. CDK1 was selected for validation of its function and molecular mechanism in GBM. This gene was significantly overexpressed in GBM cancer tissues and cells compared with normal control cells. In addition, knockdown of CDK1 clearly inhibited GBM cell proliferation. Notably, we demonstrated that CDK1 was involved in the Akt signalling pathway, where it promotes the process involved in GBM malignancy.

Complex integrated analysis of lncRNAs-miRNAs-mRNAs in oral squamous cell carcinoma

OBJECTIVES

This study aims to reveal regulatory network of lncRNAs-miRNAs-mRNAs in oral squamous cell carcinoma (OSCC) through gene expression data.

MATERIAL AND METHODS

Differentially expressed lncRNAs, miRNAs and mRNAs (cut-off: False discovery rate (FDR)<0.05 and |fold change|>1.5) were unveiled by package edgeR of R. Cox regression analysis was performed to screen prognostic factors in OSCC related with overall survival (OS) and relapse-free survival (RFS). Protein-protein interaction (PPI) network was constructed for differentially expressed mRNAs using BioGRID, HPRD and DIP. Key hub genes were identified from top 100 differentially expressed mRNAs ranked by betweenness centrality using recursive feature elimination. LncRNA-miRNA and miRNA-mRNA regulatory network were constructed and combined into ceRNAs regulatory network. Gene ontology biological terms and Kyoto Encyclopedia of Genes and Genomes pathways were identified using Fisher's exact test.

RESULTS

A total of 929 differentially expressed mRNAs, 23 differentially expressed lncRNAs and 29 differentially expressed miRNAs were identified. 59 mRNAs, 6 miRNAs (hsa-mir-133a-1, hsa-mir-1-2, hsa-mir-486, hsa-mir-135b, hsa-mir-196b, hsa-mir-193b) and 6 lncRNAs (C10orf91, C2orf48, SFTA1P, FLJ41941,PART1,TTTY14) were related with OS; and 52 mRNAs, 4 miRNAs (hsa-mir-133a-1, hsa-mir-135b, hsa-mir-196b, hsa-mir-193b) and 2 lncRNAs (PART1, TTTY14) were associated with RFS. A support vector machine (SVM) classifier containing 37 key hub genes was obtained. A ceRNA regulatory network containing 417 nodes and 696 edges was constructed. ECM-receptor interaction, cytokine-cytokine receptor interaction, focal adhesion, arachidonic acid metabolism, and p53 signaling pathway were significantly enriched in the network.

CONCLUSION

These findings uncover the pathogenesis of OSCC and might provide potential therapeutic targets.

MicroRNA-203 Inversely Correlates with Differentiation Grade, Targets c-MYC, and Functions as a Tumor Suppressor in cSCC

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer and a leading cause of cancer mortality among solid organ transplant recipients. MicroRNAs (miR) are short RNAs that regulate gene expression and cellular functions. Here, we show a negative correlation between miR-203 expression and the differentiation grade of cSCC. Functionally, miR-203 suppressed cell proliferation, cell motility, and the angiogenesis-inducing capacity of cSCC cells in vitro and reduced xenograft tumor volume and angiogenesis in vivo. Transcriptomic analysis of cSCC cells with ectopic overexpression of miR-203 showed dramatic changes in gene networks related to cell cycle and proliferation. Transcription factor enrichment analysis identified c-MYC as a hub of miR-203-induced transcriptomic changes in squamous cell carcinoma. We identified c-MYC as a direct target of miR-203. Overexpression of c-MYC in rescue experiments reversed miR-203-induced growth arrest in cSCC, which highlights the importance of c-MYC within the miR-203-regulated gene network. Together, miR-203 acts as a tumor suppressor in cSCC, and its low expression can be a marker for poorly differentiated tumors. Restoration of miR-203 expression may provide a therapeutic benefit, particularly in poorly differentiated cSCC.

Recurrent CDK1 overexpression in laryngeal squamous cell carcinoma

In this study, we analyzed the expression profile of four genes (CCNA2, CCNB1, CCNB2, and CDK1) in laryngeal squamous cell carcinoma (LSCC) cell lines and tumor samples. With the application of microarray platform, we have shown the overexpression of these genes in all analyzed LSCC samples in comparison to non-cancer controls from head and neck region. We have selected CDK1 for further analysis, due to its leading role in cell cycle regulation. It is a member of the Ser/Thr protein kinase family of proven oncogenic properties. The results obtained for CDK1 were further confirmed with the application of reverse transcription quantitative polymerase chain reaction (RT-qPCR) technique, Western blot, and immunohistochemistry (IHC). The observed upregulation of CDK1 in laryngeal squamous cell carcinoma has encouraged us to analyze for genetic mechanisms that can be responsible this phenomenon. Therefore, with the application of array-CGH, sequencing analysis and two methods for epigenetic regulation analysis (DNA methylation and miRNA expression), we tried to identify such potential mechanisms. Our attempts to identify the molecular mechanisms responsible for observed changes failed as we did not observe significant alterations neither in the DNA sequence nor in the gene copy number that could underline CDK1 upregulation. Similarly, the pyrosequencing and miRNA expression analyses did not reveal any differences in methylation level and miRNA expression, respectively; thus, these mechanisms probably do not contribute to elevation of CDK1 expression in LSCC. However, our results suggest that alteration of CDK1 expression on both mRNA and protein level probably appears on the very early step of carcinogenesis.

Diagnostic value of cyclin-dependent kinase/cyclin-dependent kinase inhibitor expression ratios as biomarkers of locoregional and hematogenous dissemination risks in oral squamous cell carcinoma

The aim of the present study was to investigate the diagnostic value of cell cycle-related genes in oral squamous cell carcinoma (OSCC) by examining the expression of the following genes in 77 OSCC tissues by quantitative polymerase chain reaction: Cyclin genes (CCNA1, CCND1, CCND2 and CCNE1), cyclin-dependent kinase (CDK) genes (CDK1, CDK2 and CDK4), CDK inhibitor genes (CDKN2A, CDKN1A, CDKN1B and CDKN1C), and integrin and associated genes that we previously reported (ITGA3, ITGB4, CD9 and JUP). The expression ratios of 66 combinations of the 11 cell cycle-related genes were analyzed to examine their associations with major clinical events using Mann-Whitney U and log-rank tests. Three expression ratios (CDK1/CDKN1B, CDK2/CDKN1A and CCNE1/CDK2) showed associations on univariate analyses and their diagnostic value was re-analyzed with integrin gene expression biomarkers (ITGA3/CD9 and ITGB4/JUP) using the Cox proportional hazards model and Kaplan-Meier estimates. Lymph node metastasis occurred in >90% of double-positive cases (high-ITGA3/CD9 and high-CDK1/CDKN1B) irrespective of tumor size (P<0.0001). Primary site recurrence was found in >30% of double-positive cases (high-ITGA3/CD9 and high-CDK2/CDKN1A) with tumors >20 mm (P=0.003). Triple-positive (high-ITGB4/JUP, high-ITGA3/CD9 and high-CDK2/CDKN1A) was associated with distant metastasis (P<0.0001), but not with other clinical parameters. Disease-specific death occurred in 55% of double-positive cases (high-ITGA3/CD9 and high-CDK2/CDKN1A) (P<0.0001) and a positive surgical margin was a significant factor for fatality in these cases. Reliable prediction of locoregional and hematogenous dissemination risks in OSCC using the four CDK and integrin gene expression ratios is a promising biomarker system. Clinical use of these parameters may improve the control rate with the use of new therapeutic strategies.

The expression of CDK1 is associated with proliferation and can be a prognostic factor in epithelial ovarian cancer

Overexpression of cyclin-dependent kinase 1 (CDK1) has been noted to correlation with several human cancers. However, the effects of CDK1 on ovarian cancer development remain unclear. The aim of this study was to examine the effect of CDK1 and related mechanism in the proliferation and resistance to chemotherapeutic drugs of epithelial ovarian cancer (EOC). Immunohistochemical analysis was performed in 119 human ovarian cancer samples, and the data were correlated with clinicopathologic features. Furthermore, Western blot analysis was performed for CDK1 in EOC samples and cell lines to evaluate their protein levels and molecular interaction. Kaplan-Meier survival analysis showed that strong expression of CDK1 exhibited a significant correlation with poor prognosis in human EOC (P = 0.02). Meanwhile, we found that knockdown CDK1 by shCDK1 promoted the apoptosis rate and increased the sensitivity to chemotherapy drugs. Thus, CDK1 might serve as a prognostic marker, and it might be of great value for experimental therapies in EOC.