Survival Benefits of Postoperative Chemotherapy in Patients With Colorectal Mucinous Adenocarcinoma: An Analysis Utilizing Propensity Score Matching From the Surveillance, Epidemiology, and End Results Database.

OBJECTIVE: This study aimed to investigate the characteristics of patients with colorectal mucinous adenocarcinoma (MAC) who benefit from postoperative chemotherapy (POCT) and to develop effective postoperative survival nomograms for predicting overall survival (OS) in colorectal MAC patients. METHODS: Data of colorectal MAC patients who underwent surgery from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2020 were collected. Patients were grouped based on POCT, and intergroup analysis was performed using 1:1 propensity score matching (PSM). Kaplan-Meier (K-M) curves were used to compare the prognosis between the 2 groups. Cox analysis was employed to identify factors associated with OS in patients with colorectal MAC who underwent POCT. The variance inflation factor (VIF) and bilateral stepwise regression were used to determine factors included in the model. Additionally, a nomogram was constructed to predict postoperative survival outcomes for patients. The discriminative ability of the nomograms was evaluated using the C-index and calibration curve analysis, the decision curve analysis (DCA) assessed the clinical utility of the nomogram, and the receiver operating characteristic (ROC) curve evaluated the nomograms' performance. RESULTS: This study encompassed 6829 patients with colorectal MAC, among whom 2258 received POCT, and 4571 did not. Whether pre or post PSM, patients in the POCT group consistently exhibited a superior median OS compared to those in the postoperative non-chemotherapy group (P < .0001). For colorectal MAC patients undergoing POCT, OS was correlated with factors such as patient age, carcinoembryonic antigen levels, tumor deposits, perineural invasion (PNI), lymph node examination count, T staging, and Grade staging. Notably, a significant chemotherapy advantage was observed in patients without perineural invasion, those with lymph node examination counts exceeding 12, and patients with moderately differentiated tumors. The overall colorectal MAC patient postoperative OS predictive nomogram demonstrated a C-index of .74, with a calibration curve near the diagonal and a DCA curve indicating positive net benefits. In comparison to TNM staging, the ROC curves of the nomogram at 1 year, 3 years, and 5 years demonstrated superior predictive capabilities (AUC: .80 vs .71, .78 vs .71, .77 vs .70). CONCLUSION: This study revealed the characteristics of colorectal MAC patients who benefit from POCT and established effective prognostic nomograms, which can aid clinicians in designing personalized treatment plans for individual patients and promote precision medicine.

A hsa_circ_001726 axis regulated by E2F6 contributes to metastasis of hepatocellular carcinoma.

BACKGROUND: CircRNAs participate in the development of hepatocellular carcinoma (HCC). This work aims to explore the key tumor promoting circRNA as a gene therapy target. METHODS: The differentially expressed gene circRNAs in HCC tumor tissues was identified by mining GSE121714 dataset. EdU staining, wound healing, transwell invasion assay, TUNEL staining and western blotting examined proliferation, migration, invasion, apoptosis and epithelial mesenchymal transition (EMT). Xenograft mouse model and orthotopic transplantation tumor mouse model were constructed to verify the role of hsa_circ_001726 in growth and metastasis of HCC. The relationship among CCT2, E2F6, hsa_circ_001726, miR-671-5p and PRMT9 was identified by RNA-fluorescence in situ hybridization, luciferase reporter assay and RNA Immunoprecipitation. RESULTS: Eleven differentially expressed circRNAs were found in HCC tumors. Among them, hsa_circ_001726 was highly expressed in HCC tumors and cells, which was transcribed from CCT2. As a transcription factor of CCT2, E2F6 knockdown inactivated CCT2 promoter and reduced hsa_circ_001726 expression. Moreover, hsa_circ_001726 elevated PRMT9 expression by sponging miR-671-5p, and then activated Notch signaling pathway. Additionally, hsa_circ_001726 deficiency repressed malignant phenotypes of HCC cells, including proliferation, migration, invasion, EMT and apoptosis. In vivo, hsa_circ_001726 deficiency reduced tumor growth and lung metastasis of HCC in xenograft mouse models and orthotopic transplantation tumor mouse models. CONCLUSION: Hsa_circ_001726 functioned as an oncogene in HCC, which was derived from CCT2 and regulated by E2F6. Hsa_circ_001726 elevated PRMT9 expression by sponging miR-671-5p, and then activated Notch signaling pathway, thereby accelerating malignant phenotypes of HCC. Therefore, targeting hsa_circ_001726 may be a new avenue for HCC treatment.

PLEKHA4 is a novel prognostic biomarker that reshapes the tumor microenvironment in lower-grade glioma.

Background: Lower-grade glioma (LGG) is a primary intracranial tumor that carry a high risk of malignant transformation and limited therapeutic options. Emerging evidence indicates that the tumor microenvironment (TME) is a superior predictor for tumor progression and therapy response. PLEKHA4 has been demonstrated to be a biomarker for LGG that correlate with immune infiltration. However, the fundamental mechanism by which PLEKHA4 contributes to LGG is still poorly understood. Methods: Multiple bioinformatic tools, including Tumor Immune Estimation Resource (TIMER), Gene Expression Profiling Interactive Analysis (GEPIA2), Shiny Methylation Analysis Resource Tool (SMART), etc., were incorporated to analyze the PLEKHA4. ESTIMATE, ssGSEA, CIBERSORT, TIDE and CellMiner algorithms were employed to determine the association of PLEKHA4 with TME, immunotherapy response and drug sensitivities. Immunohistochemistry (IHC)-based tissue microarrays and M2 macrophage infiltration assay were conducted to verify their associations. Results: PLEKHA4 expression was found to be dramatically upregulated and strongly associated with unfavorable overall survival (OS) and disease-specific survival (DSS) in LGG patients, as well as their poor clinicopathological characteristics. Cox regression analysis identified that PLEKHA4 was an independent prognostic factor. Methylation analysis revealed that DNA methylation correlates with PLEKHA4 expression and indicates a better outcome in LGG. Moreover, PLEKHA4 was remarkably correlated with immune responses and TME remodeling, as evidenced by its positive correlation with particular immune marker subsets and the putative infiltration of immune cells. Surprisingly, the proportion of M2 macrophages in TME was strikingly higher than others, inferring that PLEKHA4 may regulate the infiltration and polarization of M2 macrophages. Evidence provided by IHC-based tissue microarrays and M2 macrophage infiltration assay further validated our findings. Moreover, PLEKHA4 expression was found to be significantly correlated with chemokines, interleukins, and their receptors, further supporting the critical role of PLEKHA4 in reshaping the TME. Additionally, we found that PLEKHA4 expression was closely associated with drug sensitivities and immunotherapy responses, indicating that PLEKHA4 expression also had potential clinical significance in guiding immunotherapy and chemotherapy in LGG. Conclusion: PLEKHA4 plays a pivotal role in reshaping the TME of LGG patients, and may serve as a potential predictor for LGG prognosis and therapy.

Arginine methylation of HSPA8 by PRMT9 inhibits ferroptosis to accelerate hepatitis B virus-associated hepatocellular carcinoma progression.

BACKGROUND: The hepatitis B virus X (HBx) protein is an established cause of hepatitis B virus (HBV)-induced hepatocellular carcinoma (HCC). Whether arginine methylation regulates ferroptosis involved in HBx-induced HCC progression has not been reported. This study aimed to explore whether HBx-regulated protein arginine methyltransferase 9 (PRMT9) mediates the involvement of ferroptosis in the development of HCC. METHODS AND RESULTS: HBx inhibited ferroptosis through promoting PRMT9 expression in HCC cells. PRMT9 suppressed ferroptosis to accelerate HCC progression in vivo. PRMT9 targeted HSPA8 and enhanced arginine methylation of HSPA8 at R76 and R100 to regulate ferroptosis in HCC. HSPA8 overexpression altered the transcriptome profile of HepG2 cells, in particular, ferroptosis and immune-related pathways were significantly enriched by differentially expressed genes, including CD44. HSPA8 overexpression up-regulated CD44 expression and knockdown of CD44 significantly reversed the inhibition of ferroptosis caused by PRMT9 overexpression. CONCLUSIONS: In conclusion, HBx/PRMT9/HSPA8/CD44 axis is a vital signal pathway regulating ferroptosis in HCC cells. This study provides new opportunities and targets for the treatment of HBV-induced HCC.

Role of POU1F1 promoting the properties of stemness of gastric carcinoma through ENO1-mediated glycolysis reprogramming.

Cancer stem cells (CSCs), a rare subset of tumor cells, have been recognized as promotive role on tumor initiation and propagation. Among, aerobic glycolysis, widely clarified in multiple tumor cells, is the key for maintaining cancer stemness. Regrettably, it is largely unknown about the connection of cellular metabolic reprogramming and stemness in gastric carcinoma (GC). Two GC parental cells lines PAMC-82 and SNU-16 and their spheroids were obtained to determine the expression status of POU1F1 using quantitative real-time PCR (qRT-PCR) and western blotting analysis, respectively. Gain or loss-of-function assay was employed to assess its biological effects. Sphere formation and transwell assays were performed to evaluate the stem cell-like traits, including self-renewal capacity, migration and invasion. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were conducted for determining the binding relationship of POU1F1 on ENO1 promoter region. Herein, aberrantly upregulated POU1F1 was observed in spheroids, compared with the parental PAMC-82 and SNU-16 cells, which promoted stem cell-like traits, as representing increasing sphere formation, enhanced cell migration and invasion. Additionally, POU1F1 expression was positively with glycolytic signaling, as displaying increasing glucose consumption, lactic acid production, and extracellular acid ratio (ECAR). Furthermore, POU1F1 was identified to be a transcriptional activator of ENO1, of which overexpression remarkably abolished POU1F1 knockdown-mediated blocking effects. Taken together, we draw a conclusion that POU1F1 facilitated the stem cell-like properties of GC cells through transcriptionally augmenting ENO1 to enhance glycolysis.

RNA polymerase I subunit RPA43 activates rRNA expression and cell proliferation but inhibits cell migration.

The products synthesized by RNA polymerase I (Pol I) play fundamental roles in several cellular processes, including ribosomal biogenesis, protein synthesis, cell metabolism, and growth. Deregulation of Pol I products can cause various diseases such as ribosomopathies, leukaemia, and solid tumours. However, the detailed mechanism of Pol I-directed transcription remains elusive, and the roles of Pol I subunits in rRNA synthesis and cellular activities still need clarification. In this study, we found that RPA43 expression levels positively correlate with Pol I product accumulation and cell proliferation, indicating that RPA43 activates these processes. Unexpectedly, RPA43 depletion promoted HeLa cell migration, suggesting that RPA43 functions as a negative regulator in cell migration. Mechanistically, RPA43 positively modulates the recruitment of Pol I transcription machinery factors to the rDNA promoter by activating the transcription of the genes encoding Pol I transcription machinery factors. RPA43 inhibits cell migration by dampening the expression of c-JUN and Integrin. Collectively, we found that RPA43 plays opposite roles in cell proliferation and migration except for driving Pol I-dependent transcription. These findings provide novel insights into the regulatory mechanism of Pol I-mediated transcription and cell proliferation and a potential pathway to developing anti-cancer drugs using RPA43 as a target.

Soluble epoxide hydrolase deficiency promotes liver regeneration and ameliorates liver injury in mice by regulating angiocrine factors and angiogenesis.

BACKGROUND: Soluble epoxide hydrolase (sEH) is a key enzyme for the hydrolysis of epoxyeicosatrienoic acids (EETs) and has been implicated in the pathogenesis of hepatic inflammation, fibrosis, cancer, and nonalcoholic fatty liver disease. However, the role of sEH in liver regeneration and injury remains unclear. METHODS: This study used sEH-deficient (sEH-/-) mice and wild-type (WT) mice. Hepatocyte proliferation was assessed by immunohistochemical (IHC) staining for Ki67. Liver injury was evaluated by histological staining with hematoxylin and eosin (H&E), Masson's trichrome, and Sirius red, as well as IHC staining for α-SMA. Hepatic macrophage infiltration and angiogenesis were reflected by IHC staining for CD68 and CD31. Liver angiocrine levels were detected by ELISA. The mRNA levels of angiocrine or cell cycle-related genes were measured by quantitative real-time RT-PCR (qPCR). The protein levels of cell proliferation-related protein and phosphorylated signal transducer and activator of transcription 3 (STAT3) were detected by western blotting. RESULTS: sEH mRNA and protein levels were significantly upregulated in mice after 2/3 partial hepatectomy (PHx). Compared with WT mice, sEH-/- mice exhibited a higher liver/body weight ratio and more Ki67-positive cells on days 2 and 3 after PHx. The accelerated liver regeneration in sEH-/- mice was attributed to angiogenesis and endothelial-derived angiocrine (HGF) production. Subsequently, hepatic protein expression of cyclinD1 (CYCD1) and the downstream direct targets of the STAT3 pathway, such as c-fos, c-jun, and c-myc, were also suppressed post-PHx in sEH-/- compared to WT mice. Furthermore, sEH deficiency attenuated CCl4-induced acute liver injury and reduced fibrosis in both CCl4 and bile duct ligation (BDL)-induced liver fibrosis rodent models. Compared with WT mice, sEH-/- mice had slightly decreased hepatic macrophage infiltration and angiogenesis. Meanwhile, sEH-/- BDL mice had more Ki67-positive cells in the liver than WT BDL mice. CONCLUSIONS: sEH deficiency alters the angiocrine profile of liver endothelial to accelerate hepatocyte proliferation and liver regeneration, and blunts acute liver injury and fibrosis by inhibiting inflammation and angiogenesis. sEH inhibition is a promising target for liver diseases to improve liver regeneration and damage.

Prognostic role of preoperative inflammatory markers in postoperative patients with colorectal cancer.

Background: Inflammatory response markers are prognostic factors for several cancers, but their role in postoperative colorectal cancer (CRC) is unclear. The purpose was to evaluate the role of preoperative Neutrophil-to-Lymphocyte ratio (NLR), Platelet-to-Lymphocyte-ratio (PLR), and Lymphocyte-to-Monocyte ratio (LMR) in the prognosis of postoperative CRC patients. Methods: We retrospectively reviewed 448 CRC patients who had undergone surgical resection from December 2015 to December 2017 in our hospital. The plasma NLR, PLR, LMR, CEA, and CA19-9 were collected within 2 weeks before the operation. We recorded the clinical characteristics and survival data by reviewing medical records and phone calls. We analyzed preoperative inflammatory markers and clinical features using Pearson chi-squared tests or Fisher's tests. Uni- and multivariate Cox regression analyses were performed, and overall survival (OS) was estimated with the Kaplan-Meier method. Results: High NLR and PLR were associated with worse overall survival in postoperative CRC (HR = 2.140, 95%CI = (1.488-3.078), P < 0.001; HR =1.820, 95%CI = (1.271-2.605), P = 0.001). High LMR was associated with improved overall survival in postoperative CRC (HR = 0.341, 95%CI = (0.188-0.618), P < 0.001). In the multivariate regression analysis, the increase of NLR resulted in an increase in the risk of death (HR = 1.678, 95%CI = (1.114-2.527), P = 0.013), and for the LMR, a reduction of the risk of death (HR = 0.480, 95%CI = (0.256 - 0.902), P = 0.023). Moreover, TNM stage, CA-199, CEA, nerve or vascular invasion (NVI) and adjuvant chemotherapy after surgery also were associated with worse overall survival in postoperative CRC. Conclusion: Current evidence indicates that preoperative inflammatory markers NLR, LMR, and PLR are associated with overall survival in postoperative patients with colorectal cancer. NLR is an independent risk factor, and LMR is an independent protective factor in CRC patients after surgery.

ncR2Met (lncR2metasta v2.0): An updated database for experimentally supported ncRNAs during cancer metastatic events.

Non-coding RNAs (ncRNAs) are widely involved in cancer metastatic events (CMEs, e.g., cancer cell invasion, intravasation, extravasation, proliferation), which collaboratively accelerate tumor spread and cause high patient mortality. In early 2020, we developed a manually curated database named 'lncR2metasta' to provide a comprehensive repository for long ncRNA (lncRNA) regulation during CMEs. We updated this database by supplementing other two important ncRNA types, microRNAs (miRNAs) and circular RNAs (circRNAs), for their involvement during CMEs after a thorough manual curation from published studies. ncR2metasta documents 1565 lncRNA-associated, 882 miRNA-associated, and 628 circRNA-associated entries for ncRNA-CME associations during 50 CMEs across 63 human cancer subtypes. ncR2Met has a concise web interface for researchers to easily browse, search and download as well as to submit novel ncRNA-CME associations. We anticipated that it could be a valuable resource, which will significantly improve our understanding of ncRNA functions in metastasis. It is freely available at http://ncr2met.wchoda.com.

Clinicopathologic and prognostic factors for colorectal cancer in children and adolescents: a population-based study.

PURPOSE: Colorectal cancer (CRC) is rarely found in children and adolescents. The purpose of this study was to retrospectively conduct a population-based cohort of pediatric patients with CRC. METHODS: All pediatric patients with CRC diagnosed between 1975 and 2018 were identified using the Surveillance, Epidemiology, and End Results (SEER) database. The demographics and clinical variables of the patients were summarized, and treatment outcomes and prognostic factors were examined. The study was presented in accordance with the STROBE reporting checklist. RESULTS: A total of 284 CRC patients were identified. At 3- and 5-year follow-up, the overall survival rates were 63.1% and 52.6%, respectively. Patients with local disease had a significantly improved overall survival (OS) than patients with distant disease. At 3- and 5-year follow-up, the overall survival rates of adenocarcinoma (nos) and adenocarcinoma (polyp) were similar and significantly better than those of patients with mucinous adenocarcinoma and signet ring cell carcinoma (P < 0.001). In terms of treatment, patients who underwent surgery outlived non-surgery patients (3-year OS, 70.4% versus 26.6%, P < 0.001). Multivariate analysis revealed that SEER stage and histologic type were important independent predictors of outcomes. CONCLUSIONS: Children and adolescents with CRC are likely to be in an advanced stage, have a worse histologic subtype, and have a poorly differentiated grade. Although surgical resection considerably increases survival for the majority of patients, pediatric patients with CRC have a poor prognosis. Considerable efforts are required to improve their survival outcomes.

STAT3 promotes RNA polymerase III-directed transcription by controlling the miR-106a-5p/TP73 axis.

Deregulation of Pol III products causes a range of diseases, including neural diseases and cancers. However, the factors and mechanisms that modulate Pol III-directed transcription remain to be found, although massive advances have been achieved. Here, we show that STAT3 positively regulates the activities of Pol III-dependent transcription and cancer cell growth. RNA-seq analysis revealed that STAT3 inhibits the expression of TP73, a member of the p53 family. We found that TP73 is not only required for the regulation of Pol III-directed transcription mediated by STAT3 but also independently suppresses the synthesis of Pol III products. Mechanistically, TP73 can disrupt the assembly of TFIIIB subunits and inhibit their occupancies at Pol III target loci by interacting with TFIIIB subunit TBP. MiR-106a-5p can activate Pol III-directed transcription by targeting the TP73 mRNA 3' UTR to reduce TP 73 expression. We show that STAT3 activates the expression of miR-106a-5p by binding to the miRNA promoter, indicating that the miR-106a-5p links STAT3 with TP73 to regulate Pol III-directed transcription. Collectively, these findings indicate that STAT3 functions as a positive regulator in Pol III-directed transcription by controlling the miR-106a-5p/TP73 axis.

Transcription factor AP-2α activates RNA polymerase III-directed transcription and tumor cell proliferation by controlling expression of c-MYC and p53.

Deregulation of transcription factor AP2 alpha (TFAP2A) and RNA polymerase III (Pol III) products is associated with tumorigenesis. However, the mechanism underlying this event is not fully understood and the connection between TFAP2A and Pol III-directed transcription has not been investigated. Here, we report that TFAP2A functions as a positive factor in the regulation of Pol III-directed transcription and cell proliferation. We found TFAP2A is also required for the activation of Pol III transcription induced by the silencing of filamin A, a well-known cytoskeletal protein and an inhibitor in Pol III-dependent transcription identified previously. Using a chromatin immunoprecipitation technique, we showed TFAP2A positively modulates the assembly of Pol III transcription machinery factors at Pol III-transcribed gene loci. We found TFAP2A can activate the expression of Pol III transcription-related factors, including BRF1, GTF3C2, and c-MYC. Furthermore, we demonstrate TFAP2A enhances expression of MDM2, a negative regulator of tumor suppressor p53, and also inhibits p53 expression. Finally, we found MDM2 overexpression can rescue the inhibition of Pol III-directed transcription and cell proliferation caused by TFAP2A silencing. In summary, we identified that TFAP2A can activate Pol III-directed transcription by controlling multiple pathways, including general transcription factors, c-MYC and MDM2/p53. The findings from this study provide novel insights into the regulatory mechanisms of Pol III-dependent transcription and cancer cell proliferation.

LncRNA Pnky Positively Regulates Neural Stem Cell Migration by Modulating mRNA Splicing and Export of Target Genes.

Directed migration of neural stem cells (NSCs) is critical for embryonic neurogenesis and the healing of neurological injuries. The long noncoding RNA (lncRNA) Pnky has been reported to regulate neuronal differentiation of NSCs by interacting with PTBP1. However, its regulatory effect on NSC migration remains to be determined. Herein, we identified that Pnky is also a key regulator of NSC migration in mice, as underscored by the finding that Pnky silencing suppressed but Pnky overexpression promoted the in vitro migration of both C17.2 and NE4C murine NSCs. Additionally, in vivo cell tracking demonstrated that Pnky depletion attenuated but Pnky overexpression facilitated the migration of NE4C cells in the spinal canal after transplantation via injection into the spinal canal. Mechanistically, Pnky regulated the expression of a core set of critical regulators that direct NSC migration, including MMP2, MMP9, Connexin43, Paxillin, AKT, ERK, and P38MAPK. Using catRAPID, a web server for large-scale prediction of protein-RNA interactions, the splicing factors U2AF1 and U2AF1L4, as well as the mRNA export adaptors SARNP, Aly/Ref, and THOC7, were predicted to interact strongly with Pnky. Further investigations using colocalization and RNA immunoprecipitation (RIP) assays confirmed the direct binding of Pnky to U2AF1, SARNP, Aly/Ref, and THOC7. Transcriptomic profiling revealed that as many as 5319 differential splicing events of 3848 genes, which were highly enriched in focal adhesion, PI3K-Akt and MAPK signaling pathways, were affected by Pnky depletion. The predominant subtype of differential splicing by Pnky depletion is intron retention, followed by alternative 5' and 3' splice sites and mutually exclusive exons. Moreover, Pnky knockdown substantially blocked but Pnky overexpression facilitated the export of MMP2, Paxillin, AKT, p38MAPK, and other mRNAs to the cytosol. Collectively, our data showed that through interacting with U2AF1, SARNP, Aly/Ref, and THOC7, Pnky couples and modulates the splicing and export of target mRNAs, which consequently controlling NSC migration. These findings provide a possible theoretical basis of NSC migration regulation.

STAT3 potentiates RNA polymerase I-directed transcription and tumor growth by activating RPA34 expression.

BACKGROUND: Deregulation of either RNA polymerase I (Pol I)-directed transcription or expression of signal transducer and activator of transcription 3 (STAT3) correlates closely with tumorigenesis. However, the connection between STAT3 and Pol I-directed transcription hasn't been investigated. METHODS: The role of STAT3 in Pol I-directed transcription was determined using combined techniques. The regulation of tumor cell growth mediated by STAT3 and Pol I products was analyzed in vitro and in vivo. RNAseq, ChIP assays and rescue assays were used to uncover the mechanism of Pol I transcription mediated by STAT3. RESULTS: STAT3 expression positively correlates with Pol I product levels and cancer cell growth. The inhibition of STAT3 or Pol I products suppresses cell growth. Mechanistically, STAT3 activates Pol I-directed transcription by enhancing the recruitment of the Pol I transcription machinery to the rDNA promoter. STAT3 directly activates Rpa34 gene transcription by binding to the RPA34 promoter, which enhances the occupancies of the Pol II transcription machinery factors at this promoter. Cancer patients with RPA34 high expression lead to poor survival probability and short survival time. CONCLUSION: STAT3 potentiates Pol I-dependent transcription and tumor cell growth by activating RPA34 in vitro and in vivo.

TFIIB-related factor 1 is a nucleolar protein that promotes RNA polymerase I-directed transcription and tumour cell growth.

Eukaryotic RNA polymerase I (Pol I) products play fundamental roles in ribosomal assembly, protein synthesis, metabolism and cell growth. Abnormal expression of both Pol I transcription-related factors and Pol I products causes a range of diseases, including ribosomopathies and cancers. However, the factors and mechanisms governing Pol I-dependent transcription remain to be elucidated. Here, we report that transcription factor IIB-related factor 1 (BRF1), a subunit of transcription factor IIIB required for RNA polymerase III (Pol III)-mediated transcription, is a nucleolar protein and modulates Pol I-mediated transcription. We showed that BRF1 can be localized to the nucleolus in several human cell types. BRF1 expression correlates positively with Pol I product levels and tumour cell growth in vitro and in vivo. Pol III transcription inhibition assays confirmed that BRF1 modulates Pol I-directed transcription in an independent manner rather than through a Pol III product-to-45S pre-rRNA feedback mode. Mechanistically, BRF1 binds to the Pol I transcription machinery components and can be recruited to the rDNA promoter along with them. Additionally, alteration of BRF1 expression affects the recruitment of Pol I transcription machinery components to the rDNA promoter and the expression of TBP and TAF1A. These findings indicate that BRF1 modulates Pol I-directed transcription by controlling the expression of selective factor 1 subunits. In summary, we identified a novel role of BRF1 in Pol I-directed transcription, suggesting that BRF1 can independently regulate both Pol I- and Pol III-mediated transcription and act as a key coordinator of Pol I and Pol III.

Overexpression of lncRNA TCLlnc1 in gastric cancer predicts postoperative distant recurrence and poor survival.

TCLlnc1 was characterized as a lncRNA with oncogenic roles in T cell lymphoma, whereas its role in other diseases is unknown. We then explored the involvement of TCLlnc1 in gastric cancer. Paired gastric cancer and nontumor tissues from 66 gastric cancer patients were used to extract total RNA samples, which were used to perform RT-qPCRs to determine the expression of TCLlnc1. Plasma samples from these 66 gastric cancer patients and 66 healthy controls were also used to detect circulating TCLlnc1. Correlations of TCLlnc1 in both plasma and tissue samples with patients' clinical data were analyzed by chi-square t -test. The diagnostic value of TCLlnc1 for early-stage gastric cancer was analyzed with the receiver operating characteristic curve. A 5-year follow-up study was performed to explore the prognostic value of TCLlnc1 for the survival of gastric cancer patients. TCLlnc1 expression in tissue was increased in gastric cancer. Plasma TCLlnc1 was also increased in gastric cancer. Plasma TCLlnc1 was closely correlated with TCLlnc1 in gastric cancer tissues, but not TCLlnc1 in nontumor tissues. TCLlnc1 in plasma was only correlated with tumor distant metastasis, but not other clinical data. TCLlnc1 in plasma showed promising diagnostic value for stage I and II gastric cancer. Increased accumulation of TCLlnc1 was closely correlated with distant recurrence and poor survival during a 5-year follow-up. Therefore, TCLlnc1 is overexpressed in gastric cancer predicts postoperative distant recurrence and poor survival.

NLRP3 activation in tumor-associated macrophages enhances lung metastasis of pancreatic ductal adenocarcinoma.

Background: Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and is highly malignant due to its late diagnosis and early metastasis. Lung metastasis of PDAC occurs in a significant number of diagnosed patients and represents high severity of disease and poor clinical outcome. However, the molecular regulation of lung metastasis of PDAC is still not fully understood. Tumor-associated macrophages (TAMs) have recently been found to play an important role in cancer initiation, proliferation, progression, and metastasis. The proliferation, differentiation, and polarization of macrophages has been shown to be regulated by interleukin 1ß (IL-1ß), which is generated by NLR family pyrin domain containing 3 (NLRP3)-induced formation of inflammasome. Herein we investigated whether NLRP3 plays a role in lung metastasis of PDAC through regulation of macrophage polarization. Methods: Gene profiles for NLRP3 (+/+) and NLRP3 (-/-) macrophages obtained from the Gene Expression Omnibus (GEO) public database were compared and analyzed for altered genes related to macrophage polarization. The regulation of macrophage polarization by NLRP3 was examined in a coculture system with naïve NLRP3 (+/+) or NLRP3 (-/-) macrophages and PDAC cells. Cell growth was analyzed by a Cell Counting Kit-8 (CCK-8) assay. Cell invasiveness and migratory potential were analyzed by transwell cell invasion assay and cell migration assay, respectively. PDAC formation and lung metastasis were analyzed in a mouse model of PDAC with and without NLRP3 knockout. Results: GEO database analysis revealed significant alteration in genes that regulate macrophage polarization in NLRP3-depleted macrophages. NLRP3-depletion in macrophages seemed to favor an M1/M2b polarization. In vitro, the presence of NLRP3 in macrophages led to M2a/c/d TAM-like polarization when they were cocultured with PDAC cells. Conversely, NLRP3 depletion in macrophages led to M1/M2b polarization when they were cocultured with PDAC cells. NLRP3-depletion significantly inhibited tumor growth and stage progression in a mouse model of PDAC and significantly reduced the occurrence of lung metastasis. Conclusions: Our results suggested that NLRP3 activation in TAM enhanced lung metastasis of PDAC through regulation of TAM polarization.

Early Growth Response 1 Strengthens Pol-III-Directed Transcription and Transformed Cell Proliferation by Controlling PTEN/AKT Signalling Activity.

RNA polymerase III (Pol III) products play essential roles in ribosome assembly, protein synthesis, and cell survival. Deregulation of Pol-III-directed transcription is closely associated with tumorigenesis. However, the regulatory pathways or factors controlling Pol-III-directed transcription remain to be investigated. In this study, we identified a novel role of EGR1 in Pol-III-directed transcription. We found that Filamin A (FLNA) silencing stimulated EGR1 expression at both RNA and protein levels. EGR1 expression positively correlated with Pol III product levels and cell proliferation activity. Mechanistically, EGR1 downregulation dampened the occupancies of Pol III transcription machinery factors at the loci of Pol III target genes. Alteration of EGR1 expression did not affect the expression of p53, c-MYC, and Pol III general transcription factors. Instead, EGR1 activated RhoA expression and inhibited PTEN expression in several transformed cell lines. We found that PTEN silencing, rather than RhoA overexpression, could reverse the inhibition of Pol-III-dependent transcription and cell proliferation caused by EGR1 downregulation. EGR1 could positively regulate AKT phosphorylation levels and is required for the inhibition of Pol-III-directed transcription mediated by FLNA. The findings from this study indicate that EGR1 can promote Pol-III-directed transcription and cell proliferation by controlling the PTEN/AKT signalling pathway.

Structural Variation of Precipitates Formed by Fe(II) Oxidation and Impact on the Retention of Phosphate.

The oxidation-precipitation process of Fe(II) is ubiquitous in the environment and critically affects the fate of contaminants and nutrients in natural systems where Fe(II) is present. Here, we explored the effect of H2O2 concentration on the structure of precipitates formed by Fe(II) oxidation and compared the precipitates to those formed by Fe(III) hydrolysis. Additionally, the phosphate retention under different H2O2 concentrations was evaluated. XRD, TEM, PDA, XPS, and UV-visible absorbance spectroscopy were used to characterize the structure of the formed precipitates; UV-visible absorbance spectroscopy was also used to determine the residual phosphate and Fe(II) in solution. It was found that the predominant precipitates in Fe(II) solution changed from planar-shaped crystalline lepidocrocite (γ-FeOOH) to poor short-range order (poorly crystalline) spherical-shaped hydrous ferric oxide (HFO) with increasing H2O2 concentrations. Although the HFO precipitates formed from Fe(II) resembled those formed from Fe(III) hydrolysis, the former was larger and had clearer lattice fringes. During the formation of γ-FeOOH, both Fe(II)-Fe(III) complexes and ligand-to-metal charge transfer processes were observed, and it was found that Fe(II) was present in the planar-shaped precipitates. Fe(II) might be present in the interior of precipitates as Fe(OH)2, which could serve as a nucleus for the epitaxial growth of γ-FeOOH. In addition, the extent of phosphate retention increased with the H2O2 concentration, indicating the increased reactivity of formed precipitates with H2O2 concentration. More phosphate was retained via coprecipitation with Fe than adsorption on the preformed Fe precipitates due to the incorporation of phosphate within the structure of the formed Fe hydroxyphosphate via coprecipitation.