Research progress on the relationship between the TOR signaling pathway regulator, epigenetics, and tumor development.

Almost all cellular activities depend on protein folding, signaling complex assembly/disassembly, and epigenetic regulation. One of the most important regulatory mechanisms responsible for controlling these cellular processes is dynamic protein phosphorylation/dephosphorylation. Alterations in phosphorylation networks have major consequences in the form of disorders, including cancer. Many signaling cascades, including the target of rapamycin (TOR) signaling, are important participants in the cell cycle, and dysregulation in their phosphorylation/dephosphorylation status has been linked to malignancies. As a TOR signaling regulator, protein phosphatase 2A (PP2A) is responsible for most of the phosphatase activities inside the cells. On the other hand, TOR signaling pathway regulator (TIPRL) is an essential PP2A inhibitory protein. Many other physiological roles have also been suggested for TIPRL, such as modulation of TOR pathways, apoptosis, and cell proliferation. It is also reported that TIPRL was increased in various carcinomas, including non-small-cell lung carcinoma (NSCLC) and hepatocellular carcinomas (HCC). Considering the function of PP2A as a tumor suppressor and also the effect of the TIPRL/PP2A axis on apoptosis and proliferation of cancer cells, this review aims to provide a complete view of the role of TIPRL in cancer development in addition to describing TIPRL/PP2A axis and its epigenetic regulation.

Comprehensive Evaluation of the m6A Regulator Prognostic Risk Score in the Prediction of Immunotherapy Response in Clear Cell Renal Cell Carcinoma.

Background: Clear cell renal cell carcinoma (ccRCC) is known for its high drug resistance. The tumor-immune crosstalk mediated by the epigenetic regulation of N6-methyladenosine (m6A) modification has been demonstrated in recent studies. Therefore, m6A modification-mediated immune cell infiltration characteristics may be helpful to guide immunotherapy for ccRCC. Methods: This study comprehensively analyzed m6A modifications using the clinical parameters, single-cell RNA sequencing data, and bulk RNA sequencing data from the TCGA-ccRC cohort and 13 external validation cohorts. A series of bioinformatic approaches were applied to construct an m6A regulator prognostic risk score (MRPRS) to predict survival and immunotherapy response in ccRCC patients. Immunological characteristics, enriched pathways, and mutation were evaluated in high- and low-MRPRS groups. Results: The expressional alteration landscape of m6A regulators was profiled in ccRCC cell clusters and tissue. The 8 regulator genes with minimal lambda were integrated to build an MRPRS, and it was positively correlated with immunotherapeutic response in extent validation cohorts. The clinicopathological features and immune infiltration characteristics could be distinguished by the high- and low-MRPRS. Moreover, the MRPRS-mediated mutation pattern has an enhanced response to immune checkpoint blockade in the ccRCC and pan-cancer cohorts. Conclusions: The proposed MRPRS is a promising biomarker to predict clinical outcomes and therapeutic responses in ccRCC patients.

Comprehensive Analysis of APA Events and Their Association With Tumor Microenvironment in Lung Adenocarcinoma.

BACKGROUND: Alternative polyadenylation (APA) is a pervasive posttranscriptional mechanism regulating gene expression. However, the specific dysregulation of APA events and its potential biological or clinical significance in lung adenocarcinoma (LUAD) remain unclear. METHODS: Here, we collected RNA-Seq data from two independent datasets: GSE40419 (n = 146) and The Cancer Genome Atlas (TCGA) LUAD (n = 542). The DaPars algorithm was employed to characterize the APA profiles in tumor and normal samples. Spearman correlation was used to assess the effects of APA regulators on 3' UTR changes in tumors. The Cox proportional hazard model was used to identify clinically relevant APA events and regulators. We stratified 512 patients with LUAD in the TCGA cohort through consensus clustering based on the expression of APA factors. FINDINGS: We identified remarkably consistent alternative 3' UTR isoforms between the two cohorts, most of which were shortened in LUAD. Our analyses further suggested that aberrant usage of proximal polyA sites resulted in escape from miRNA binding, thus increasing gene expression. Notably, we found that the 3' UTR lengths of the mRNA transcriptome were correlated with the expression levels of APA factors. We further identified that CPSF2 and CPEB3 may serve as key regulators in both datasets. Finally, four LUAD subtypes according to different APA factor expression patterns displayed distinct clinical results and oncogenic features related to tumor microenvironment including immune, metabolic, and hypoxic status. INTERPRETATION: Our analyses characterize the APA profiles among patients with LUAD and identify two key regulators for APA events in LUAD, CPSF2 and CPEB3, which could serve as the potential prognostic genes in LUAD.

FAM83A is amplified and promotes tumorigenicity in non-small cell lung cancer via ERK and PI3K/Akt/mTOR pathways.

Family with sequence similarity 83A (FAM83A) is a newly-found over-expressed oncogene in several types of cancers and associates with poor prognosis. However, the role that FAM83A may play in the carcinogenesis of non-small cell lung cancer (NSCLC) still needs to be defined. The present study aimed to investigate the function of FAM83A in NSCLC progression and to investigate the possible mechanism. Analysis of Gene Expression Omnibus (GEO) database and rt-PCR showed up-regulated expression of FAM83A in NSCLC. GEO and the Cancer Genome Atlas (TCGA) data analysis revealed that high expression level of FAM83A in NSCLC was associated with poor prognosis. In vitro experiments showed that depleting FAM83A by siRNA/shRNA significantly inhibited cell proliferation and induced cell apoptosis. Cell motility was also retarded after silencing FAM83A, as demonstrated by Transwell assay. FAM83A depletion in A549 cells also inhibited subcutaneous tumor growth and lung metastasis in vivo. Western blotting showed that silencing FAM83A decreased the phosphorylation of ERK and PI3K/Akt/mTOR. On the other hand, overexpressing FAM83A in vitro enhanced cell proliferation and invasiveness, which was repressed by PI3K inhibitor and ERK inhibitor separately. Taken together, our study suggests that FAM83A promotes tumorigenesis of NSCLC at least partly via ERK and PI3K/Akt/mTOR pathways, making it a promising therapeutic target.

Lobectomy with high-position single-intercostal two-port video-assisted thoracoscope for non-small cell lung cancer is a safe and effective surgical procedure.

BACKGROUND: High-position single-intercostal two-port video-assisted thoracic surgery (VATS) technique has been used for thoracic diseases. It can effectively avoid postoperative chronic pain compared with the traditional three-port VATS. This study aimed to evaluate the safety and efficacy of high-position single-intercostal two-port video-assisted thoracoscopic lobectomy. METHODS: From June 2014 to December 2018, a total of 474 patients in our hospital with non-small cell lung cancer (NSCLC) underwent lobectomy with a high-position single-intercostal two-port video-assisted thoracoscope. A retrospective study of these patients was conducted, and follow-up was performed to analyze the patients' 3- and 5-year survival rates. RESULTS: Of the total number of patients, 27.6%, 41.4%, and 31% underwent surgery between the third, fourth, and fifth intercostals, respectively. During the operation, 31 patients were converted to open surgery or three-port thoracoscopic surgery. The average surgical time was 160.9±44.9 min, the average postoperative hospital stay was 5.6±3.4 days, the incidence of postoperative complications was 7.2%, and the average number of lymph nodes resected was 13.6±5.3. The 3-year overall survival (OS) rate of IA1, IA2, IA3, IB, IIA, IIB and IIIA was 99.0%, 98.6%, 96.3%, 91.2%, 85.7%, 66.7%, and 60.8%, respectively. Meanwhile, the 5-year OS rate of IA1, IA2, IA3, IB, and IIIA was 99.0%, 94.5%, 87.5%, 85.5%, and 43.3%, respectively. CONCLUSIONS: Lobectomy with a high-position single-intercostal two-port video-assisted thoracoscope for NSCLC is a safe and effective surgical procedure.

Degradation of CCNB1 mediated by APC11 through UBA52 ubiquitination promotes cell cycle progression and proliferation of non-small cell lung cancer cells.

OBJECTIVE: Mechanism by which CCNB1 regulates the cell cycle progression and its prognostic function in non-squamous non-small cell lung cancer (NSCLC) are necessary to be further elucidated. METHODS: Data retrieved from gene expression omnibus (GEO) and cancer genome atlas (TCGA) combined with clinical data were used. Survival analysis was conducted in public datasets. Proteomics and co-immunoprecipation assays were designed to unravel proteins with interaction with CCNB1. Short hairpin RNA and small interfering RNA as well as overexpressing genes of interest were used. RESULTS: CCNB1 was not implicated in apoptosis, migration and invasion of NSCLC cells. After either knockdown or overexpression of CCNB1, the occurrence of cell cycle arrest in G2/M phase, fewer cloning formation and diminished dimension of xenograft tumors were observed. CCNB1 expression level was clinically associated with several clinicopathological parameters including gender, smoking, T stage and N stage. Survival analysis showed that the higher level of CCNB1, the more dismal outcome in overall survival as well as in disease-free survival. Mechanistically, we confirmed that the role of CCNB1 on cell cycle and cloning formation was dependent on UBA52, which was able to promote degradation of CCNB1; nevertheless, this consequence relied on APC11. Knockdown of APC11 led to cell cycle arrest in G2/M and less cloning formation even in the presence of overexpressed UBA52. Following upregulation of APC11, the protein of CCNB1 degraded with resultant cell cycle progression and more cloning formation. CONCLUSION: Degradation of CCNB1 by APC11 via UBA52 ubiquitylation was critical in cell cycle progression and proliferation of NSCLC cell lines.

Tissue-type plasminogen activator gene targets thrombolysis in atriums.

Our previous investigations showed that retroviral gene transfer of tissue-type plasminogen activator (tPA) effectively targeted thrombolysis in vitro and in the model of inferior caval veins of rabbits. This study is to identify the target thrombolysis of retroviral vector recombinant pLEGFP-N1-tPA transferred into the tissue around the Dacron patch (the same materials making of the ring of mechanical valve) in left atriums of rabbits. 70 Dacron patches were transplanted into the left atriums of 70 New Zealand white rabbits. The rabbits were randomly divided into three groups according to the different handling methods, including local pLEGFP-N1-tPA transferred group (gene therapy group, 30 animals), pLEGFP-N1 transferred group (control group, 20 animals), medium DMEM + 10% neonate calf serum (NCS) injected group (blank control group, 20 animals). Samples of blood, Dacron pieces and left atriums (auricles) wall from half of above in each group were harvested on second day and another half were harvested on 75th day after surgery. The EGFP expression of harvested left atriums (auricles) wall were observed under the confocal. The thrombi on the surface of Dacron patches were detected by stereoscope and electron microscope. The tPA expression in left atriums (auricles) wall and in blood from left atriums were detected by Western blot and their thrombolysis and activities were observed and calculated in plasma plates. ELISA were used to identify the contents of tPA. No thrombus was seen on the surface of Dacron patches that were transplanted in left atriums by tPA locally transferring around them. Activity and content of tPA were high in local tissue of left atrium and in blood of left atrium. It demonstrated effectively thrombolysis by tPA rapidly, efficiently and long expressing. This puts the foundation of mechanical valve replacement model for tPA gene valve, next.