CircPDE5A-encoded novel regulator of the PI3K/AKT pathway inhibits esophageal squamous cell carcinoma progression by promoting USP14-mediated de-ubiquitination of PIK3IP1.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a common gastrointestinal tumor and has become an important global health problem. The PI3K/AKT signaling pathway plays a key role in the development of ESCC. CircRNAs have been reported to be involved in the regulation of the PI3K/AKT pathway, but the underlying mechanisms are unclear. Therefore, this study aimed to identify protein-coding circRNAs and investigate their functions in ESCC. METHODS: Differential expression of circRNAs between ESCC tissues and adjacent normal tissues was identified using circRNA microarray analysis. Thereafter, LC-MS/MS was used to identify circPDE5A-encoded novel protein PDE5A-500aa. Molecular biological methods were used to explore the biological functions and regulatory mechanisms of circPDE5A and PDE5A-500aa in ESCC. Lastly, circRNA-loaded nanoplatforms were constructed to investigate the therapeutic translation value of circPDE5A. RESULTS: We found that circPDE5A expression was down-regulated in ESCC cells and tissues and that it was negatively associated with advanced clinicopathological stages and poorer prognosis in ESCC. Functionally, circPDE5A inhibited ESCC proliferation and metastasis in vitro and in vivo by encoding PDE5A-500aa, a key regulator of the PI3K/AKT signaling pathway in ESCC. Mechanistically, PDE5A-500aa interacted with PIK3IP1 and promoted USP14-mediated de-ubiquitination of the k48-linked polyubiquitin chain at its K198 residue, thereby attenuating the PI3K/AKT pathway in ESCC. In addition, Meo-PEG-S-S-PLGA-based reduction-responsive nanoplatforms loaded with circPDE5A and PDE5A-500aa plasmids were found to successfully inhibit the growth and metastasis of ESCC in vitro and in vivo. CONCLUSION: The novel protein PDE5A-500aa encoded by circPDE5A can act as an inhibitor of the PI3K/AKT signaling pathway to inhibit the progression of ESCC by promoting USP14-mediated de-ubiquitination of PIK3IP1 and may serve as a potential target for the development of therapeutic agents.

Analysis of prognostic factors and establishment of prognostic model for primary mediastinal germ cell tumors: a case controlled study.

BACKGROUND: The overall prognosis of primary mediastinal germ cell tumors (PMGCTs) is poor and the associated prognostic factors are not fully understood. Our goal was to investigate the prognostic factors of PMGCTs and to develop a validated prognostic prediction model. MATERIALS AND METHODS: A total of 114 PMGCTs with specific pathological types were included in this study. Clinicopathological characteristics of nonseminomatous PMGCTs and mediastinal seminomas were compared using the χ2 or Fisher's exact test. Independent prognostic factors of nonseminomatous PMGCTs screened using the univariate and multivariate Cox regression analysis were then used to generate a nomogram. The predictive performance of the nomogram was evaluated using the concordance index, decision curve, and the area under the receiver operating characteristic curve (AUC) and validated by bootstrap resampling. The Kaplan-Meier curves of independent prognostic factors were analyzed. RESULTS: This study included 71 cases of nonseminomatous PMGCTs and 43 cases of mediastinal seminomas. The 3-year overall survival rates for nonseminomatous PMGCTs and mediastinal seminomas patients were 54.5 and 97.4%, respectively. The overall survival prognostic nomogram for nonseminomatous PMGCTs was established by integrating independent prognostic factors, including the Moran-Suster stage, white blood cell, hemoglobin, and platelet-lymphocyte ratio. The nomogram demonstrated good performance with a concordance index of 0.760 and the 1-year and 3-year AUC values of 0.821 and 0.833, respectively. These values were better than those of the Moran-Suster stage system. The bootstrap validation had an AUC of 0.820 (0.724-0.915) and showed a well-fitting calibration curve. Besides, patients with mediastinal seminomas showed favorable clinical outcomes and all the nine patients received neoadjuvant therapy and postoperative surgery achieved pathological complete response. CONCLUSION: A nomogram based on staging and blood routine examination results was established to accurately and consistently predict the prognosis of patients with nonseminomatous PMGCTs.

A propensity score-matched analysis of neoadjuvant chemoimmunotherapy versus surgery alone for locally advanced esophageal squamous cell carcinoma.

BACKGROUND: The aim of this study was to evaluate the safety, efficacy, and oncologic outcomes of neoadjuvant immunotherapy combined with chemotherapy (NICT) group and surgery alone group in the treatment of patients with locally advanced esophageal squamous cell carcinoma (ESCC). METHODS: A series of 232 consecutive patients who underwent surgery with or without NICT from June 2019 to August 2022 were evaluated. We performed propensity score matching between the NICT and surgery alone groups on the basis of estimated propensity scores for each patient. RESULTS: After propensity score matching, data of 137 patients with clinical stages II-IV ESCC, including 85 receiving surgery alone and 52 receiving NICT, were analyzed. Compared with the surgery alone group (301.7 ± 94.4 min), the operation time was significantly longer in the NICT group (333.4 ± 79.7 min). However, there was no significant difference between the two groups in the postoperative complications, intraoperative blood loss, thoracic fluid volume, chest tube duration, lengths of intensive care unit stay and postoperative hospitalization. Additionally, 90-day mortality rate and 30-day readmission were similar in both groups. CONCLUSIONS: Overall, NICT followed by esophagectomy appears to be safe and feasible for locally advanced ESCC. However, further multicenter prospective clinical trials are needed to validate our results.

The comparison of manual and mechanical anastomosis after total pharyngolaryngoesophagectomy.

Background: Total pharyngolaryngoesophagectomy (TPLE) is considered as a curative treatment for hypopharynx cancer and cervical esophageal carcinomas (HPCECs). Traditional pharyngo-gastric anastomosis is usually performed manually, and postoperative complications are common. The aim of this study was to introduce a new technique for mechanical anastomosis and to evaluate perioperative outcomes and prognosis. Methods: From May 1995 to Nov 2021, a series of 75 consecutive patients who received TPLE for a pathological diagnosis of HPCECs at Sun Yat-sen Memorial Hospital were evaluated. Mechanical anastomosis was performed in 28 cases and manual anastomosis was performed in 47 cases. The data from these patients were retrospectively analyzed. Results: The mean age was 57.6 years, and 20% of the patients were female. The rate of anastomotic fistula and wound infection in the mechanical group were significantly lower than that in the manual group. The operation time, intraoperative blood loss and postoperative hospital stays were significantly higher in the manual group than that in the mechanical group. The R0 resection rate and the tumor characteristics were not significantly different between groups. There was no significant difference in overall survival and disease-free survival between the two groups. Conclusion: The mechanical anastomosis technology adopted by this study was shown to be a safer and more effective procedure with similar survival comparable to that of manual anastomosis for the HPCECs patients.

Effects of Lipid Metabolism-Related Genes PTGIS and HRASLS on Phenotype, Prognosis, and Tumor Immunity in Lung Squamous Cell Carcinoma.

Background: Lipid metabolism reprogramming played an important role in cancer occurrence, development, and immune regulation. The aim of this study was to identify and validate lipid metabolism-related genes (LMRGs) associated with the phenotype, prognosis, and immunological characteristics of lung squamous cell carcinoma (LUSC). Methods: In the TCGA cohort, bioinformatics and survival analysis were used to identify lipid metabolism-related differentially expressed genes (DEGs) associated with the prognosis of LUSC. PTGIS/HRASLS knockdown and overexpression effects on the LUSC phenotype were analyzed in vitro experiments. Based on the expression distribution of PTGIS/HRASLS, LUSC patients were divided into two clusters by consensus clustering. Clinical information, prognosis, immune infiltration, expression of immune checkpoints, and tumor mutation burden (TMB) level were compared between the TCGA and GSE4573 cohorts. The genes related to clustering and tumor immunity were screened by weighted gene coexpression network analysis (WGCNA), and the target module genes were analyzed by functional enrichment analysis, protein-protein interaction (PPI) analysis, and immune correlation analysis. Results: 191 lipid metabolism-related DEGs were identified, of which 5 genes were independent prognostic genes of LUSC. PTGIS/HRASLS were most closely related to LUSC prognosis and immunity. RT-qPCR, western blot (WB) analysis, and immunohistochemistry (IHC) showed that the expression of PTGIS was low in LUSC, while HRASLS was high. Functionally, PTGIS promoted LUSC proliferation, migration, and invasion, while HRASLS inhibited LUSC proliferation, migration, and invasion. The two clusters' expression and distribution of PTGIS/HRASLS had the opposite trend. Cluster 1 was associated with lower pathological staging (pT, pN, and pTNM stages), better prognosis, stronger immune infiltration, higher expression of immune checkpoints, and higher TMB level than cluster 2. WGCNA found that 28 genes including CD4 and IL10RA were related to the expression of PTGIS/HRASLS and tumor immune infiltration. PTGIS/HRASLS in the GSE4573 cohort had the same effect on LUSC prognosis and tumor immunity as the TCGA cohort. Conclusions: PTGIS and HRASLS can be used as new therapeutic targets for LUSC as well as biomarkers for prognosis and tumor immunity, which has positive significance for guiding the immunotherapy of LUSC.

Development and clinical validation of a necroptosis-related gene signature for prediction of prognosis and tumor immunity in lung adenocarcinoma.

Necroptosis is a new programmed formation of necrotizing cell death, which plays important role in tumor biological regulation, including tumorigenesis and immunity. In this study, we aimed to establish and validate a prediction model based on necroptosis-related genes (NRGs) for lung adenocarcinoma (LUAD) prognosis and tumor immunity. The training set consisted of samples from The Cancer Genome Atlas (TCGA) dataset (n = 334), and the validation sets consisted of samples from the Gene Expression Omnibus (GEO) (n = 439) and clinical (n = 20) datasets. Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that 28 necroptosis-related differentially expressed genes (DEGs) were enriched in cell death and immune regulation. RT-qPCR and western blot results showed the low expression of necroptosis markers in LUAD cells. A prognostic gene signature based on 6 NRGs (PYGB, IL1A, IFNAR2, BIRC3, H2AFY2, and H2AFX) was constructed and the risk score was calculated. Multivariate Cox regression analysis showed that the risk score was an independent risk factor [hazard ratio (HR) = 1.220, 95% confidence interval (CI): 1.154-1.290, P<0.001]. In the TCGA cohort, a high-risk score was associated with poor prognosis, weak immune infiltration, and low expression at immune checkpoints, which was validated in the GEO and clinical cohorts. Our findings showed that the patients in the low-risk group had a better progression-free survival (PFS) [not reached vs. 8.5 months, HR = 0.18, 95% CI: 0.04-0.72, P<0.001] than those in the high-risk score group. Immunotherapy tolerance was found to be correlated with the high-risk score, and the risk score combined with PD-L1 (AUC = 0.808, 95% CI: 0.613-1.000) could better predict the immunotherapy response of LUAD. A nomogram was shown to have a strong ability to predict the individual survival rate of patients with LUAD in the TCGA and GSE68465 cohorts. We constructed and validated a potential prognostic signature consisting of 6 NRGs to predict the prognosis and tumor immunity of LUAD, which may be helpful to guide the individualized immunotherapy of LUAD.

[Retracted] MicroRNA­19a­3p inhibits the cellular proliferation and invasion of non­small cell lung cancer by downregulating UBAP2L.

[This retracts the article DOI: 10.3892/etm.2020.8926.].

A Nomogram Model to Predict Post-Progression Survival in Esophageal Squamous Cell Carcinoma Patients With Recurrence After Radical Resection.

Background: Esophageal squamous cell carcinoma (ESCC) is characterized clinically by frequent recurrence, leading to a poor prognosis after radical surgery. The aim of this study was to identify a prognostic nomogram to predict the post-progression survival (PPS) of ESCC patients based on the features of primary tumor and recurrence. Methods: A total of 234 ESCC patients who underwent recurrence after radical surgery were enrolled in this study. The independent prognostic factors screened by the univariate and multivariate Cox regression analysis were subsequently used to construct a nomogram. The predictive performance of the nomogram was evaluated with the concordance index (C-index), decision curve, and the area under the receiver operating characteristic curve (AUC) and validated in two validation cohorts. The Kaplan-Meier curves of different recurrence patterns were analyzed. Results: The prognostic nomogram of PPS was established by integrating independent prognostic factors, including age, body mass index, number of lymph node dissection, recurrence pattern, and recurrence treatment. The nomogram demonstrated good performance, with C-index values of 0.756, 0.817, and 0.730 for the training and two validation cohorts. The 1-year AUC values were 0.773, 0.798, and 0.735 and 3-year AUC values were 0.832, 0.871, and 0.791, respectively. Furthermore, we found that patients with bone metastasis displayed the worst PPS compared to other isolated recurrence patterns. Conclusion: We constructed a nomogram to reliably predict PPS, which would be valuable to provide individual managements for ESCC patients after radical surgery.

Highly sensitive Curcumin-conjugated nanotheranostic platform for detecting amyloid-beta plaques by magnetic resonance imaging and reversing cognitive deficits of Alzheimer's disease via NLRP3-inhibition.

BACKGROUND: Alzheimer's disease (AD) is the most common neurodegenerative disorder without effective therapy and lack diagnosis strategy for preclinical AD patients. There is an urgent need for development of both early diagnosis and therapeutic intervention of AD. RESULTS: Herein, we developed a nanotheranostics platform consisting of Curcumin (Cur), an anti-inflammatory molecule, and superparamagnetic iron oxide (SPIO) nanoparticles encapsulated by diblock 1,2-dio-leoyl-sn-glycero-3-phosphoethanolamine-n-[poly(ethylene glycol)] (DSPE-PEG) that are modified with CRT and QSH peptides on its surface. Furthermore, we demonstrated that this multifunctional nanomaterial efficiently reduced ß-amyloid plaque burden specifically in APP/PS1 transgenic mice, with the process noninvasively detected by magnetic resonance imaging (MRI) and the two-dimensional MRI images were computed into three-dimension (3D) plot. Our data demonstrated highly sensitive in vivo detection of ß-amyloid plaques which more closely revealed real deposition of Aß than previously reported and we quantified the volumes of plaques for the first time based on 3D plot. In addition, memory deficits of the mice were significantly rescued, probably related to inhibition of NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasomes. CONCLUSIONS: Gathered data demonstrated that this theranostic platform may have both early diagnostic and therapeutic potential in AD.

A Propensity Score-Matched Analysis of Thoracolaparoscopic vs Open McKeown's Esophagectomy.

BACKGROUND: The effectiveness and survival benefit of minimally invasive esophagectomy compared to open esophagectomy (OE) remain controversial. The aim of this study was to evaluate the safety, efficacy, and oncologic outcomes of McKeown's total minimally invasive esophagectomy (tMIE) and McKeown's OE in the treatment of patients with esophageal squamous cell carcinoma. METHODS: A series of 917 consecutive patients (306 OE and 611 tMIE) who underwent McKeown's esophagectomy for esophageal squamous cell carcinoma in the Department of Thoracic Surgery at Sun Yat-sen University Cancer Center from January 2011 to December 2016 were evaluated. We performed propensity matching between the tMIE and OE groups on the basis of estimated propensity scores for each patient. RESULTS: After propensity-matched analysis, 288 patients were selected from each group. The rate of postoperative complications, such as pneumonia, respiratory insufficiency, cervical anastomotic leakage, and wound infection, in the OE group was significantly higher than that in the tMIE group. Intraoperative blood loss and operative duration were not significantly different between the matched groups, whereas the tMIE group had a shorter length of intensive care unit stay and postoperative hospital stay than the OE group. The R0 resection rate and the number of lymph nodes harvested were not significantly different between groups. There was no significant difference in median overall survival between the 2 groups after matching. CONCLUSIONS: McKeown's tMIE was shown to be a safe and effective procedure with long-term survival comparable to that of OE for the patients with esophageal squamous cell carcinoma.

Family history of cancer is a prognostic factor for better survival in operable esophageal squamous cell carcinoma: A propensity score matching analysis.

Lay summary: Patients with a family history of cancer, especially digestive tract cancer and esophageal cancer, a family history of cancer in the first degree, and more than one relative affected by cancer were associated with favorable survival when compared to those without a family history of cancer. Precis for use in the Table of Contents: A family history of cancer is a favorable independent prognostic factor in ESCC. Patients with a family history of cancer, especially digestive tract cancer and esophageal cancer, a family history of cancer in the first degree, and more than one relative affected by cancer were associated with favorable survival when compared to those without a family history of cancer. Background: A family history of cancer (FH) is closely associated with the risk and survival of many cancers. However, the effect of FH on the prognosis of patients with esophageal squamous cell carcinoma (ESCC) remains unclear. We performed a large cohort study in the Chinese population to obtain insight into the prognostic value of FH in patients with operable ESCC. Methods: A total of 1,322 consecutive patients with thoracic ESCC who had undergone esophagectomy between January 1997 and December 2013 were included. The FH group included patients with any degree of FH, while the non-FH group included patients without any degree of FH. In total, 215 patients with FH and 215 without FH were matched using the propensity score matching analysis method to adjust for differences in baseline variables between the two groups. The impact of FH on disease-free survival (DFS) and overall survival (OS) was estimated using the Kaplan-Meier method and Cox's proportional hazards models. Results: Before matching, 280 (21.2%) patients were included in the FH group and 1,042 (78.8%) in the non-FH group. FH was associated with early pathological T stage (p = 0.001), lymph node-negative status (p = 0.022), and early pathological stage (p = 0.006). After matching, FH was an independent prognostic factor for DFS and OS in ESCC patients. Patients with FH had 35% lower risk of disease progression (hazard ratio [HR] = 0.65, 95% CI: 0.51-0.84, p = 0.001) and 34% lower risk of death (HR = 0.66, 95% CI: 0.51-0.86, p = 0.002) than those without FH. Patients with a family history of digestive tract cancer (FH-DC), a family history of esophageal cancer (FH-EC), FH in first-degree relatives (FH-FD), and more than one relative affected by cancer were associated with favorable DFS and OS as compared to those without FH. Conclusion: FH is a favorable independent prognostic factor in ESCC. Patients with FH, especially those with FH-DC, FH-EC, FH-FD, and more than one relative affected by cancer, had improved survival.

Prognostic impact of sterilized lymph nodes in esophageal squamous cell carcinomas after neoadjuvant chemoradiotherapy.

BACKGROUND: The prognostic importance of sterilized lymph nodes (SLN) remains unclear in patients with esophageal squamous cell carcinomas (ESCC) treated by neoadjuvant chemoradiotherapy (nCRT). This study aimed to determine whether SLN predicted disease-free survival (DFS) in ESCC. METHODS: We enrolled 246 eligible patients who were divided into SLN (+) and SLN (-) group according to the presence or absence of fibrosis, necrosis, calcifications and/or foreign body giant cell reactions in the negative lymph nodes specimens. The prognostic value of SLN was determined using univariate and multivariate analyses. The prognostic strength of counting SLN as positive lymph nodes was evaluated using the difference of Akaike information criterion (ΔAIC). RESULTS: A total of 61 SLN were identified in 38 (15.4%) patients. There was no significant difference in baseline characteristics between SLN (+) and SLN (-) group. The most frequently detected SLN in the thoracic cavity and abdominal cavity were those along bilateral recurrent laryngeal nerve (21/38,55.3%) and left gastric artery (13/24,60.9%), respectively. The univariate and multivariate analyses showed SLN was an independent prognostic factor for worse DFS in the whole cohort (HR = 2.05, 95%CI = 1.08-3.90, P = 0.029). The SLN (+) group additionally correlated with worse 5-year DFS than SLN (-) group in the ypT0, ypN0 and pCR subgroups. Counting SLN as positive lymph nodes showed better prognostic strength than ignoring them. CONCLUSION: SLN was of prognostic significance for worse DFS in patients with ESCC, particularly in patients with good response to nCRT.

MicroRNA-19a-3p inhibits the cellular proliferation and invasion of non-small cell lung cancer by downregulating UBAP2L.

MicroRNAs (miRNAs) are increasingly recognized as important regulators of non-small cell lung cancer (NSCLC) progression by directly regulating their target genes. The aim of the present study was to assess the biological role of miR-19a-3p in NSCLC. It was revealed that miR-19a-3p expression was significantly downregulated in human NSCLC tissues and cell lines compared with normal tissues and lung epithelial cells. In addition, a lower miR-19a-3p expression was significantly associated with Tumor Node Metastasis stage and lymph node metastasis. Furthermore, the upregulation of miR-19a-3p in NSCLC cell lines significantly inhibited cell proliferation, migration and invasion, as determined using an MTT, colony formation, wound healing and transwell Matrigel invasion assays, respectively. A luciferase reporter assay and western blotting determined that ubiquitin associated protein 2 like (UBAP2L) was a direct target of miR-19a-3p and could be inhibited through the upregulation of miR-19a-3p in NSCLC. In addition, UBAP2L silencing induced similar effects to those observed following miR-19a-3p overexpression. The overexpression of UBAP2L partially reversed the effects of miR-19a-3p on NSCLC cell lines. Collectively, these data indicated that miR-19a-3p may serve as a tumor suppressor partly through the regulation of UBAP2L expression in NSCLC and that the targeting of miR-19a-3p may be a novel method for NSCLC treatment.

Fibrin sealant for esophageal anastomosis: A phase II study.

BACKGROUND: Esophagectomy is a pivotal curative modality for localized esophageal or esophagogastric junction cancer (EC or EJC). Postoperative anastomotic leakage (AL) remains problematic. The use of fibrin sealant (FS) may improve the strength of esophageal anastomosis and reduce the incidence of AL. AIM: To assess the efficacy and safety of applying FS to prevent AL in patients with EC or EJC. METHODS: In this single-arm, phase II trial (Clinicaltrial.gov identifier: NCT03529266), we recruited patients aged 18-80 years with resectable EC or EJC clinically staged as T1-4aN0-3M0. An open or minimally invasive McKeown esophagectomy was performed with a circular stapled anastomosis. After performing the anastomosis, 2.5 mL of porcine FS was applied circumferentially. The primary endpoint was the proportion of patients with AL within 3 mo. RESULTS: From June 4, 2018, to December 29, 2018, 57 patients were enrolled. At the data cutoff date (June 30, 2019), three (5.3%) of the 57 patients had developed AL, including two (3.5%) with esophagogastric AL and one (1.8%) with gastric fistula. The incidence of anastomotic stricture and other major postoperative complications was 1.8% and 17.5%, respectively. The median time needed to resume oral feeding after operation was 8 d (Interquartile range: 7.0-9.0 d). No adverse events related to FS were recorded. No deaths occurred within 90 d after surgery. CONCLUSION: Perioperative sealing with porcine FS appears safe and may prevent AL after esophagectomy in patients with resectable EC or EJC. Further phase III studies are warranted.

[Applicable Value of AMSS-PCR in Lung Cancer Gene Mutation Detection].

BACKGROUND: The detection of driver oncogenes of lung cancer is of great importance. There are various gene detection techniques nowadays which are different from each other. We carried out this study to investigate the specificity and sensitivity of assay panels based on an Amplification Refractory Mutation System-polymerase chain reaction (ARMS-PCR) technique of Amplification Mutation Specific System (AMSS) in detection of lung cancer gene mutation. To estimate the applicable value of assay panels in clinical settings. METHODS: We collected cancer tissue specimens or fluid specimens from 309 patients. Mutation results were presented for those samples previously detected by ARMS-PCR. In comparison, we carried out AMSS-PCR using (epidermal growth factor receptor, EGFR) assay panel and Six-Alliance assay panel as well as Sanger sequencing. Software SPSS 22.0 (SPSS IBM) was used for statistical analysis. RESULTS: The rates of consistency between the results by assay panels and Sanger sequencing or ARMS-PCR were 97.41% and 97.73%, respectively. Besides, EGFR assay panel had higher consistency rates with other detection methods than Six-Alliance assay panel. As for consistency test, the Kappa values of assay panels with Sanger sequencing, assay panels with ARMS-PCR, and ARMS-PCR with Sanger sequencing were 0.946, 0.953, and 0.913, respectively. The receiver operating characteristic curve (ROC) area under curve (AUC) of assay panels was 0.976 referring to Sanger sequencing, and 0.975 as ARMS-PCR was referred to. CONCLUSIONS: AMSS-PCR can make an optimal cancer gene mutation detection method for clinical settings.

MiR-520b restrains cell growth by targeting HDAC4 in lung cancer.

BACKGROUND: MicroRNAs (miRNAs) function as tumor promoting or tumor suppressing factors in many cancers. MiR-520b contributes to progression in head-neck and liver cancers, spinal osteosarcoma, and glioma; however, the association of miR-520b with lung cancer progression remains unknown. In this investigation, we explore the effect of miR-520b targeting HDAC4 on lung cancer growth. METHODS: The regulation of miR-520b or its inhibitor on HDAC4 expression was analyzed using Western blot analysis. After treatment of miR-520b or its inhibitor, miR-520b and HDAC4 levels were examined using quantitative real time-PCR. The modulation of miR-520b on HDAC4 was investigated by luciferase reporter gene assay. Cell proliferation evaluation was performed using colony formation and methyl-thiazolyl-tetrazolium assays. The correlation between miR-520b and HDAC4 in human clinical samples was verified using Pearson's correlation coefficient. RESULTS: An obvious decrease in HDAC4 expression was observed in lung cancer A549 cells treated with different doses of miR-520b. The miR-520b inhibitor enhanced HDAC4 expression in lung cancer cells. Bioinformatics predicted the targeting of miR-520b on HDAC4. MiR-520b directly targeted the 3' untranslated region of HDAC4. The introduction of miR-520b obviously inhibited cell proliferation in vitro. Anti-miR-520b was capable of accelerating lung cancer cell proliferation; however, HDAC4 knockdown destroyed anti-miR-520b-induced cell proliferation. Finally, a negative correlation between miR-520b and HDAC4 was observed in clinical human lung cancer samples. CONCLUSION: MiR-520b decreases HDAC4 expression to control cell proliferation in lung cancer.

Solitary Pulmonary Lesion in Patients with History of Malignancy: Primary Lung Cancer or Metastatic Cancer?

BACKGROUND: Defining the status of solitary pulmonary lesion (SPL) in patients with history of malignancy is important because primary lung cancer (PLC) or intrapulmonary metastasis might indicate different surgical strategies. The aim of this study is to identify factors related to the status of these lesions and construct a clinical model to estimate the pretest probability of PLC. METHODS: From January 2005 to January 2016, 104 patients with previous malignancy and suitable for surgery were retrospectively studied. Univariate and multivariate analyses were performed to identify possible factors related to SPLs. A nomogram was constructed to differentiate PLC from intrapulmonary metastasis. RESULTS: Ninety-seven (93.3%) patients were diagnosed as malignant postoperatively, including 61 patients with intrapulmonary metastasis and 36 patients with PLC. Multivariate analysis showed that site of primary tumor [head and neck squamous cell cancer: odds ratio (OR) = 28.509, P = 0.006; genitourinary cancer: OR = 23.928, P = 0.012], negative lymph node status of primary tumor (OR = 3.154, P = 0.038), spiculation of SPL (OR = 3.972, P = 0.022), and central location of SPL (OR = 4.679, P = 0.026) were four independent factors differentiating PLC from intrapulmonary metastasis. All of these were included in the nomogram. The C-index of the nomogram for predicting probability was 0.82. CONCLUSIONS: Incidence of malignant SPLs was fairly high in patients with history of malignancy. A nomogram including site and lymph node status of primary tumor, and spiculation and location of SPL might be a good tool for differentiating PLC from intrapulmonary metastasis preoperatively and guiding treatment.

Disassembly of mitotic checkpoint complexes by the joint action of the AAA-ATPase TRIP13 and p31(comet).

The mitotic (or spindle assembly) checkpoint system delays anaphase until all chromosomes are correctly attached to the mitotic spindle. When the checkpoint is active, a Mitotic Checkpoint Complex (MCC) assembles and inhibits the ubiquitin ligase Anaphase-Promoting Complex/Cyclosome (APC/C). MCC is composed of the checkpoint proteins Mad2, BubR1, and Bub3 associated with the APC/C activator Cdc20. When the checkpoint signal is turned off, MCC is disassembled and the checkpoint is inactivated. The mechanisms of the disassembly of MCC are not sufficiently understood. We have previously observed that ATP hydrolysis is required for the action of the Mad2-binding protein p31(comet) to disassemble MCC. We now show that HeLa cell extracts contain a factor that promotes ATP- and p31(comet)-dependent disassembly of a Cdc20-Mad2 subcomplex and identify it as Thyroid Receptor Interacting Protein 13 (TRIP13), an AAA-ATPase known to interact with p31(comet). The joint action of TRIP13 and p31(comet) also promotes the release of Mad2 from MCC, participates in the complete disassembly of MCC and abrogates checkpoint inhibition of APC/C. We propose that TRIP13 plays centrally important roles in the sequence of events leading to MCC disassembly and checkpoint inactivation.

Thyroid hormone receptor interacting protein 13 (TRIP13) AAA-ATPase is a novel mitotic checkpoint-silencing protein.

The mitotic checkpoint (or spindle assembly checkpoint) is a fail-safe mechanism to prevent chromosome missegregation by delaying anaphase onset in the presence of defective kinetochore-microtubule attachment. The target of the checkpoint is the E3 ubiquitin ligase anaphase-promoting complex/cyclosome. Once all chromosomes are properly attached and bioriented at the metaphase plate, the checkpoint needs to be silenced. Previously, we and others have reported that TRIP13 AAA-ATPase binds to the mitotic checkpoint-silencing protein p31(comet). Here we show that endogenous TRIP13 localizes to kinetochores. TRIP13 knockdown delays metaphase-to-anaphase transition. The delay is caused by prolonged presence of the effector for the checkpoint, the mitotic checkpoint complex, and its association and inhibition of the anaphase-promoting complex/cyclosome. These results suggest that TRIP13 is a novel mitotic checkpoint-silencing protein. The ATPase activity of TRIP13 is essential for its checkpoint function, and interference with TRIP13 abolished p31(comet)-mediated mitotic checkpoint silencing. TRIP13 overexpression is a hallmark of cancer cells showing chromosomal instability, particularly in certain breast cancers with poor prognosis. We suggest that premature mitotic checkpoint silencing triggered by TRIP13 overexpression may promote cancer development.