Activation of cyclin D1-related kinase in human lung adenocarcinoma

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

Objective

To study the relationship between cyclin-dependent protein kinase 6 (CDK6) expression in diffuse large B-cell lymphoma (DLBCL) and the clinical biological behavior and prognosis.

Methods

Data mining was performed using the Oncomine and The Cancer Genome Atlas (TCGA) databases to analyze the expression level of CDK6 in DLBCL. CDK6 alterations in DLBCL and related functional networks were analyzed with c-BioPortal and the Gene Set Enrichment Analysis was performed by using DAVID and FunRich software. In addition, screening for differential gene expression of CDK6 was done and enriched by using LinkedOmics. Finally, formalin-fixed and paraffin-embedded (FFPE) tissue samples from 102 patients with DLBCL were collected from the Department of Pathology, Shanxi Cancer Hospital (Taiyuan, Shanxi, China) from January 2015 through December 2020. All cases had complete clinical course records. Thirty cases of lymph node reactive hyperplasia tissues were used as controls. The expression of CDK6 in DLBCL tissues was detected by qRT‑PCR and immunohistochemistry.

Results

Bioinformatics analysis: The data showed that mRNA expression level and DNA copy number variations (CNVs) of CDK6 were significantly higher in DLBCL as compared to normal tissue (P ˂ 0.05). Based on C-BioPortal analysis, we speculated that amplification was the most common copy of CDK6 CNV in DLBCL. Through Gene Ontology (GO) analysis of these genes, it was found that the proteins were mainly located in the nucleus and cytoplasm. The biological interaction network of CDK6 alterations were found to participate primarily in the G1-S phase of the process. Analysis of LinkedOmics mRNA sequencing data showed that three genes were positively correlated with CDK6 expression: PSMD1, C2orf29 and ASB1. Through experimental verification, we found that CDK6 was overexpressed in DLBCL, and the expression of CDK6 mRNA and protein in DLBCL were positively correlated with Ann Arbor staging and IPI score (P<0.05), and negatively correlated with overall survival (P<0.001).

Conclusion

Data mining results and experiments revealed and confirmed multi-level evidence for the importance of CDK6 in DLBCL; hence, CDK6 may be a potential marker in DLBCL. Thus, our study will perhaps lay the foundation for further research on the role of CDK6 in the genesis and development of DLBCL.

Transection of the cervical sympathetic trunk inhibits the progression of pulmonary arterial hypertension via ERK-1/2 Signalling

Background

Abnormal sympathetic hyperactivity has been shown to lead to pulmonary arterial hypertension (PAH) deterioration. The purpose of this study was to examine whether the transection of the cervical sympathetic trunk (TCST) can inhibit the progression of PAH in a monocrotaline (MCT)-induced PAH model and elucidate the underlying mechanisms.

Methods

Rats were randomly divided into four groups, including a control group, an MCT group, an MCT + sham group and an MCT + TCST group. After performing haemodynamic and echocardiographic measurements, the rats were sacrificed for the histological study, and the norepinephrine (NE) concentrations and protein expression level of tyrosine hydroxylase (TH) were evaluated. The protein expression levels of extracellular signal-regulated kinase (ERK)-1/2, proliferating cell nuclear antigen (PCNA), cyclin A2 and cyclin D1 in pulmonary artery vessels and pulmonary arterial smooth muscle cells (PASMCs) were determined.

Results

Compared with the MCT + sham group, TCST profoundly reduced the mean pulmonary arterial pressure (mPAP) (22.02 ± 4.03 mmHg vs. 31.71 ± 2.94 mmHg), right ventricular systolic pressure (RVSP) (35.21 ± 5.59 mmHg vs. 48.36 ± 5.44 mmHg), medial wall thickness (WT%) (22.48 ± 1.75% vs. 46.10 ± 3.16%), and right ventricular transverse diameter (RVTD) (3.78 ± 0.40 mm vs. 4.36 ± 0.29 mm) and increased the tricuspid annular plane systolic excursion (TAPSE) (2.00 ± 0.12 mm vs. 1.41 ± 0.24 mm) (all P < 0.05). The NE concentrations and protein expression levels of TH were increased in the PAH rats but significantly decreased after TCST. Furthermore, TCST reduced the increased protein expression of PCNA, cyclin A2 and cyclin D1 induced by MCT in vivo. We also found that NE promoted PASMC viability and activated the ERK-1/2 pathway. However, the abovementioned NE-induced changes could be suppressed by the specific ERK-1/2 inhibitor U0126.

Conclusion

TCST can suppress pulmonary artery remodelling and right heart failure in MCT-induced PAH. The main mechanism may be that TCST decreases the NE concentrations in lung tissues, thereby preventing NE from promoting PASMC proliferation mediated by the ERK-1/2 signalling pathway.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1090-2) contains supplementary material, which is available to authorized users.

Angiotensin receptor blocker telmisartan inhibits cell proliferation and tumor growth of cholangiocarcinoma through cell cycle arrest

Cholangiocarcinoma (CCA) is at an advanced stage at the time of its diagnosis, and developing a more effective treatment of CCA would be desirable. Angiotensin II type 1 (AT1) receptor blocker (ARB), telmisartan may inhibit cancer cell proliferation, but the mechanisms by which telmisartan affects various cancers remain unknown. In this study, we evaluated the effects of telmisartan on human CCA cells and to assess the expression of microRNAs (miRNAs). We studied the effects of telmisartan on CCA cells using two cell lines, HuCCT-1 and TFK-1. In our experiments, telmisartan inhibited the proliferation of HuCCT-1 and TFK-1 cells. Additionally, telmisartan induced G0/G1 cell cycle arrest via blockade of the G0 to G1 cell cycle transition. Notably, telmisartan did not induce apoptosis in HuCCT-1 cells. This blockade was accompanied by a strong decrease in cell cycle-related protein, especially G1 cyclin, cyclin D1, and its catalytic subumits, Cdk4 and Cdk6. Telmisartan reduced the phosphorylation of EGFR (p-EGFR) and TIMP-1 by using p-RTK and angiogenesis array. Furthermore, miRNA expression was markedly altered by telmisartan in HuCCT-1. Telmisartan inhibits tumor growth in CCA xenograft model in vivo. In conclusion, telmisartan was shown to inhibit human CCA cell proliferation by inducing cell cycle arrest.

miR-186 downregulation correlates with poor survival in lung adenocarcinoma, where it interferes with cell-cycle regulation

Deeper mechanistic understanding of lung adenocarcinoma (non-small cell lung carcinoma, or NSCLC), a leading cause of cancer-related deaths overall, may lead to more effective therapeutic strategies. In analyzing NSCLC clinical specimens and cell lines, we discovered a uniform decrease in miR-186 (MIR186) expression in comparison with normal lung tissue or epithelial cell lines. miR-186 expression correlated with patient survival, with median overall survival time of 63.0 or 21.5 months in cases exhibiting high or low levels of miR-186, respectively. Enforced overexpression of miR-186 in NSCLC cells inhibited proliferation by inducing G(1)-S checkpoint arrest. Conversely, RNA interference-mediated silencing miR-186 expression promoted cell-cycle progression and accelerated the proliferation of NSCLC cells. Cyclin D1 (CCND1), cyclin-dependent kinase (CDK)2, and CDK6 were each directly targeted for inhibition by miR-186 and restoring their expression reversed miR-186-mediated inhibition of cell-cycle progression. The inverse relationship between expression of miR-186 and its targets was confirmed in NSCLC tumor xenografts and clinical specimens. Taken together, our findings established a tumor-suppressive role for miR-186 in the progression of NSCLC.

Quantitative proteomics reveals regulation of karyopherin subunit alpha-2 (KPNA2) and its potential novel cargo proteins in nonsmall cell lung cancer

The process of nucleocytoplasmic shuttling is mediated by karyopherins. Dysregulated expression of karyopherins may trigger oncogenesis through aberrant distribution of cargo proteins. Karyopherin subunit alpha-2 (KPNA2) was previously identified as a potential biomarker for nonsmall cell lung cancer by integration of the cancer cell secretome and tissue transcriptome data sets. Knockdown of KPNA2 suppressed the proliferation and migration abilities of lung cancer cells. However, the precise molecular mechanisms underlying KPNA2 activity in cancer remain to be established. In the current study, we applied gene knockdown, subcellular fractionation, and stable isotope labeling by amino acids in cell culture-based quantitative proteomic strategies to systematically analyze the KPNA2-regulating protein profiles in an adenocarcinoma cell line. Interaction network analysis revealed that several KPNA2-regulating proteins are involved in the cell cycle, DNA metabolic process, cellular component movements and cell migration. Importantly, E2F1 was identified as a potential novel cargo of KPNA2 in the nuclear proteome. The mRNA levels of potential effectors of E2F1 measured using quantitative PCR indicated that E2F1 is one of the "master molecule" responses to KPNA2 knockdown. Immunofluorescence staining and immunoprecipitation assays disclosed co-localization and association between E2F1 and KPNA2. An in vitro protein binding assay further demonstrated that E2F1 interacts directly with KPNA2. Moreover, knockdown of KPNA2 led to subcellular redistribution of E2F1 in lung cancer cells. Our results collectively demonstrate the utility of quantitative proteomic approaches and provide a fundamental platform to further explore the biological roles of KPNA2 in nonsmall cell lung cancer.

Requirement for CDK4 kinase function in breast cancer

Cyclin D1 is overexpressed in the majority of human breast cancers. We previously found that mice lacking cyclin D1 are resistant to mammary carcinomas triggered by the ErbB-2 oncogene. In this study, we investigated which function of cyclin D1 is required for ErbB-2-driven mammary oncogenesis. We report that the ability of cyclin D1 to activate cyclin-dependent kinase CDK4 underlies the critical role for cyclin D1 in breast cancer formation. We also found that the continued presence of CDK4-associated kinase activity is required to maintain breast tumorigenesis. We analyzed primary human breast cancers and found high cyclin D1 levels in a subset (approximately 25%) of ErbB-2-overexpressing tumors. We propose that this subset of breast cancer patients might benefit from inhibiting CDK4 kinase.

Gene expression profiling of malignant mesothelioma cell lines: cDNA array study

To reveal genes relevant for malignant mesothelioma (MM), we carried out cDNA array experiments on 4 MM cell lines and 2 primary mesothelial cell cultures established from pleural fluid of non-cancer patients. Human cancer gene filters including 588 genes were used for the cDNA array experiments. Our study revealed 26 over-expressed genes that play a role in the regulation of cell fate, cell cycle, cell growth and DNA damage repair and 13 under-expressed genes encoding growth factors, receptors and proteins involved in cell adhesion, motility and invasion to be common to 3 or 4 MM cell lines. We confirmed the cDNA array results using RT-PCR for 5 of the over-expressed genes and for 3 of the under-expressed genes. Our study presents gene expression profiles in MM cell lines and shows the involvement of several genes, such as those encoding JAGGED1, ser/thr protein kinase NIK, Ku80 and cyclin D2, novel in MM.