P300 Interacted With N-Myc and Regulated Its Protein Stability via Altering Its Post-Translational Modifications in Neuroblastoma.

MYCN amplification is an independent risk factor for poor prognosis in neuroblastoma (NB), but its protein product cannot be directly targeted because of protein structure. Thus, this study aimed to explore novel ways to indirectly target N-Myc by regulating its post-translational modifications (PTMs) and therefore protein stability. N-Myc coimmunoprecipitation combined with HPLC-MS/MS identified 16 PTM residues and 114 potential N-Myc-interacting proteins. Notably, both acetylation and ubiquitination were identified on lysine 199 of N-Myc. We then discovered that p300, which can interact with N-Myc, modulated the protein stability of N-Myc in MYCN-amplified NB cell lines and simultaneously regulated the acetylation level and ubiquitination level on lysine-199 of N-Myc protein in vitro. Furthermore, p300 correlated with poor prognosis in NB patients. Taken together, p300 can be considered as a potential therapeutic target to treat MYCN-amplified NB patients, and other identified PTMs and interacting proteins also provide potential targets for further study.

KHSRP modulated cell proliferation and cell cycle via regulating PPP2CA and p27 expression in Wilms tumor.

Wilms tumor (WT) is the most common renal malignancy in children, and the survival rate of high-risk WT patients was still low despite multimodality therapy. KHSRP, an RNA-binding protein, has been proved to be relative to tumor progression in different kinds of malignancies, but the function of KHSRP in WT remained unclear. Here, our study aimed to explore and clarify the function of KHSRP in WT cells and its molecular mechanism. Thus, our results showed that KHSRP was highly expressed in WT tumor tissues compared to normal kidney tissues and correlated with poor prognosis in WT patients. Downregulation of KHSRP using siRNAs in WT cell line SK-NEP-1 and Wit49 resulted in inhibition of cell proliferation and cell cycle arrest via stabilizing and upregulating p27 protein. Furthermore, mechanistic analyses revealed that KHSRP bound to 3'UTR of PPP2CA mRNA and modulating its mRNA stability, resulting in regulation of the phosphorylation level and protein stability of p27 in WT cell lines. In conclusion, our results demonstrated that KHSRP played an important role in WT and modulated cell proliferation and cell cycle via regulating the expression of PPP2CA and p27.

Pan­cancer analyses reveal the regulation and clinical outcome association of PCLAF in human tumors.

Studies have shown that PCNA clamp associated factor (PCLAF) plays a paramount role in a variety of cancers; however, the expression profile and the specific molecular mechanism of PCLAF in cancer remains unclear, as is its value in the human pan­cancer analysis. Based on the publicly available datasets of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), a comprehensive analysis of the probable carcinogenic effects of the PCLAF gene was performed in 33 human cancers. It was found that PCLAF is highly expressed in cancer tissues compared with normal tissues, and is significantly correlated with poor prognosis. We found that the eight tumors with significantly high PCLAF expression presented with decreased DNA methylation levels of PCLAF, including cholangiocarcinoma (CHOL), cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), glioblastoma multiforme (GBM), pheochromocytoma and paraganglioma (PCPG), sarcoma (SARC), testicular germ cell tumor (TGCT), stomach adenocarcinoma (STAD), and uterine corpus endometrial carcinoma (UCEC). The expression of PCLAF was found to be positively correlated with activated CD4 T cells (Act CD4) and type 2 T helper (Th2) cells, suggesting that PCLAF may play a particular role in tumor immune infiltration. In addition, the functional mechanism of PCLAF also involves the mitotic cell cycle process, cell division, and DNA replication. Our first pan­cancer study provides a relatively extensive understanding of the carcinogenic effects of PCLAF in miscellaneous tumors.

PCLAF promotes neuroblastoma G1/S cell cycle progression via the E2F1/PTTG1 axis.

PCLAF (PCNA clamp-associated factor), also known as PAF15/ KIAA0101, is overexpressed in most human cancers and is a predominant regulator of tumor progression. However, its biological function in neuroblastoma remains unclear. PCLAF is extremely overexpressed in neuroblastoma and is associated with poor prognosis. Through the analysis of various data sets, we found that the high expression of PCLAF is positively correlated with increased stage and high risk of neuroblastoma. Most importantly, knocking down PCLAF could restrict the proliferation of neuroblastoma cells in vitro and in vitro. By analyzing RNA-seq data, we found that the enrichment of cell cycle-related pathway genes was most significant among the differentially expressed downregulated genes after reducing the expression of PCLAF. In addition, PCLAF accelerated the G1/S transition of the neuroblastoma cell cycle by activating the E2F1/PTTG1 signaling pathway. In this study, we reveal the mechanism by which PCLAF facilitates cell cycle progression and recommend that the PCLAF/E2F1/PTTG1 axis is a therapeutic target in neuroblastoma.

Successful thoracoscopic repair of traumatic diaphragmatic hernia in a child.

Traumatic diaphragmatic hernia is very rare in children, and the diagnosis is often missed or delayed. Herein, we reported a 2-year-old boy who had suffered with traumatic diaphragmatic hernia due to a car crash. The child was manifested as tachypnoea without any other severe symptoms. The computed tomography scanning showed his right diaphragm was rupture. Soon, this patient was received a thoracoscopic repair surgery, and he was discharged 2 weeks later without any complication.

Comparative Study of Thoracoscopic and Modified Small Incision Repair for Congenital Diaphragmatic Eventration in Children.

Background: Thoracoscopic diaphragmatic plication has gained popularity in the treatment of congenital diaphragmatic eventration (CDE), but the therapeutic effect and prognosis have rarely been compared with nonendoscopic surgery. Materials and Methods: The medical records of 77 children who had received treatment for CDE in our institution from September 2006 to January 2019 were retrospectively analyzed. According to the repair approach, the children were divided into a thoracoscopic plication group and a modified small incision plication group. The perioperative characteristics and follow-up details after diaphragm plication were compared between the two groups. Results: Among 77 children with CDE, 44 cases were in the thoracoscopic plication group and 33 cases were in the modified small incision plication group. All the cases of CDE were unilateral, with 13 cases on the left side and 64 cases on the right side. There were no differences in the preoperative characteristics between the two groups. The modified small incision plication group had a higher bleeding volume (P = .000) and a greater proportion of patients needing chest drainage (P = .000), whereas the differences in the total and postoperative hospital stays (P = .088, P = .247, respectively) did not significantly differ between the two groups. There were no differences in postoperative improvement in the location of the diaphragm between the two groups or between the right and left lesions (P = .438, P = .677, respectively). The total follow-up time was 2-11 years. No recurrence was reported during this period in either of the groups, but the incidence of postoperative thoracic deformities was higher in the modified small incision plication group (P = .013). Conclusions: Compared with the modified small incision plication, thoracoscopic plication has the advantages of smaller blood loss, a low percentage of intrathoracic drainage tube usage, and no occurrence of thoracic deformities.

Prp19 Is an Independent Prognostic Marker and Promotes Neuroblastoma Metastasis by Regulating the Hippo-YAP Signaling Pathway.

Pre-mRNA processing factor 19 (Prp19) was previously reported to be involved in tumor progression. However, Prp19 expression and its functions remain elusive in neuroblastoma. Here, we aim to identify the functions and mechanisms of Prp19 in neuroblastoma. Neuroblastic tumor tissue microarrays and two independent validation data sets indicate that Prp19 is associated with high-risk markers and bone marrow metastasis and serves as a prognostic marker for worse clinical outcomes with neuroblastoma. Gain- and loss-of-expression assays reveal that Prp19 promotes invasion, migration, and epithelial-mesenchymal transition (EMT) of neuroblastoma cells in vitro. Bioinformatics analysis of RNA-seq data shows that the expressions of YAP and its downstream genes are significantly inhibited after downregulation of Prp19. Prp19 and YAP expression in metastatic lymph nodes is higher than in situ neuroblastoma tissue. Further experiments show that Prp19 regulates YAP expression and consequently affects cell invasion, migration, and EMT in neuroblastoma by pre-mRNA splicing of YAP. In conclusion, our findings provide the first evidence that Prp19 is a potential therapeutic target and prognostic biomarker for patients with neuroblastoma.

MYT1 attenuates neuroblastoma cell differentiation by interacting with the LSD1/CoREST complex.

Impaired neuronal differentiation is a feature of neuroblastoma tumorigenesis, and the differentiation grade of neuroblastoma tumors is associated with patient prognosis. Detailed understanding of the molecular mechanisms underlying neuroblastoma differentiation will facilitate the development of effective treatment strategies. Recent studies have shown that myelin transcription factor 1 (MYT1) promotes vertebrate neurogenesis by regulating gene expression. We performed quantitative analysis of neuroblastoma samples, which revealed that MYT1 was differentially expressed among neuroblastoma patients with different pathological diagnoses. Analysis of clinical data showed that MYT1 overexpression was associated with a significantly shorter 3-year overall survival rate and poor differentiation in neuroblastoma specimens. MYT1 knockdown inhibited proliferation and promoted the expression of multiple differentiation-associated proteins. Integrated omics data indicated that many genes involved in neuro-differentiation were regulated by MYT1. Interestingly, many of these genes are targets of the REST complex; therefore, we further identified the physical interaction of MYT1 with LSD1/CoREST. Depletion of LSD1 or inhibition of LSD1 by ORY-1001 decreased MYT1 expression, providing an alternative approach to target MYT1. Taken together, our results indicate that MYT1 significantly attenuates cell differentiation by interacting with the LSD1/CoREST complex. MYT1 is, therefore, a promising therapeutic target for enhancing the neurite-inducing effect of retinoic acid and for inhibiting the growth of neuroblastoma.

Overexpression of Rad51 predicts poor prognosis and silencing of Rad51 increases chemo-sensitivity to doxorubicin in neuroblastoma.

Outcome for children with high-risk neuroblastoma (NB) remains suboptimal. Recurrence and metastasis caused by chemo-resistance is an underlying mechanism contributing to the poor prognosis. Aberrant expression of Rad51 is implicated in both radio- and chemo-sensitivity in many human malignancies. However, its clinical significance and relationship with chemo-sensitivity in NB remain undefined. In this study, Rad51 expression was first evaluated in 70 surgically resected NB specimens by immunochemistry using tissue microarray and the correlation with clinic-pathologic features including survival was assessed. We then conducted microarray-based search with the Tumor Neuroblastoma public datasets to validate the immunochemistry results. Furthermore, the role of Rad51 in drug sensitivity was studied by using short hairpin RNA in the human NB SK-N-BE(2) and SH-SY5Y cells with treatment of doxorubicin. Our findings demonstrated for the first time that Rad51 is a prognostic marker in NB and down-regulation of Rad51 can lead to chemo-sensitizing effect in human NB cells.

Both serum and tissue Galectin-1 levels are associated with adverse clinical features in neuroblastoma.

BACKGROUND: Neuroblastoma is one of the most common pediatric solid tumors. Although the 5-year overall survival rate has increased over the past few decades, high-risk patients still have a poor prognosis due to a lack of biomonitoring therapy. This study was performed to investigate the role of Galectin-1 in neuroblastoma biomonitoring therapy. PROCEDURE: A tissue microarray containing 37 neuroblastoma tissue samples was used to evaluate the correlation between Galectin-1 expression and clinical features. Blood samples were examined to better understand whether serum Galectin-1 (sGalectin-1) could be used for biomonitoring therapy. Kaplan-Meier analysis and ROC analysis was conducted to distinguish the outcome associated with high or low expression of Galectin-1 in patients with neuroblastoma. RESULTS: Increased Galectin-1 expression was found in neuroblastoma and it was further demonstrated that elevated tissue Galectin-1 expression was related to INSS stage, histology, bone marrow metastasis, and poor survival. sGalectin-1 levels were higher in newly diagnosed patients with neuroblastoma than healthy subjects. Patients with elevated sGalectin-1 through treatment cycles correlated with the poor chemo-responses and tended to have worse outcomes, such as metastasis or stable tumor size, whereas gradually decreasing sGalectin-1 levels correlated with no observed progression in clinical symptoms. CONCLUSIONS: Tissue and serum Galectin-1 levels were associated with adverse clinical features in patients with neuroblastoma, and sGalectin-1 could be a potential biomarker for monitoring therapy.

Annexin A2 could enhance multidrug resistance by regulating NF-κB signaling pathway in pediatric neuroblastoma.

BACKGROUND: Chemotherapy is one of major therapeutic regimens for neuroblastoma (NB) in children. However, recurrence and metastasis associated with poor prognosis caused by acquired multidrug resistance remains a challenge. There is a great need to achieve new insight into the molecular mechanism of drug resistance in NB. The aim of this study is to identify novel drug sensitivity-related biomarkers as well as new therapeutic targets to overcome chemoresistance. METHODS: We proteome-wide quantitatively compared protein expression of two NB cell lines with different drug sensitivities, isolated from the same patient prior to and following chemotherapy. Annexin A2 (ANXA2) emerged as a key factor contributing to drug resistance in NB. Then, we assessed the correlation of ANXA2 expression and clinical characteristics using a tissue microarray. Further, the roles of ANXA2 in chemoresistance for NB and the underlying mechanisms were studied by using short hairpin RNA (shRNA) in vitro and vivo. RESULTS: First in total, over 6000 proteins were identified, and there were about 460 significantly regulated proteins which were up- or down-regulated by greater than two folds. We screened out ANXA2 which was upregulated by more than 12-fold in the chemoresistant NB cell line, and it might be involved in the drug resistance of NB. Then, using a tissue chip containing 42 clinical NB samples, we found that strong expression of ANXA2 was closely associated with advanced stage, greater number of chemotherapy cycles, tumor metastasis and poor prognosis. Following knockdown of ANXA2 in NB cell line SK-N-BE(2) using shRNA, we demonstrate enhanced drug sensitivity for doxorubicin (2.77-fold) and etoposide (7.87-fold) compared with control. Pro-apoptotic genes such as AIF and cleaved-PARP were upregulated. Inhibiting ANXA2 expression attenuated transcriptional activity of NF-κB via down-regulated nuclear translocation of subunit p50. Finally, simulated chemotherapy in a xenograft NB nude mouse model suggests that ANXA2 knockdown could improve clinical results in vivo. CONCLUSION: Our profiling data provided a rich source for further study of the molecular mechanisms of acquired drug resistance in NB. Further study may determine the role of ANXA2 as a prognostic biomarker and a potential therapeutic target for patients with multidrug-resistant NB.