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Objective To investigate the regulatory effects of transmembrane protein with EGF-like and two follistatin-like domain 1(TMEFF1/tomoregulin 1) on the proliferation and migration of neuroblastoma (NB) cell line SN-K-BE(2). Methods TMEFF1 mRNA in neuroblastoma cell lines SN-K-BE(2), IMR32, SK-N-SH, SK-N-AS and normal cell lines MCF10A and hTERT RPE-1 was detected by RT-qPCR. Small interfering RNA (siRNA) was used to construct transient knockdown TMEFF1 normal and SN-K-BE (2) NB cell lines. The effect of transient knockdown of TMEFF1 mRNA was examined by RT-qPCR. After transfection of SN-K-BE (2) cells with siRNA, cell proliferation was detected by colony-forming unit assay and real-time cell analysis (RTCA). The positive rate of Ki-67 cells was determined by immunofluorescence staining. CellTiter-Glo (CTG) was used to detect cell activity. Stable knockdown of TMEFF1 was performed in SK-N-BE(2) cells by short hairpin RNA (shRNA) lentiviral infection, the stable outcomes of TMEFF1 was also detected by RT-qPCR. Cell proliferation was detected by coloning formation, RTCA and CTG. In addition, the positive rate of Ki-67 cells was detected by immunofluorescence,the cell mobility was measured by cell scratch assay. Results Compared with normal cell lines, the expression of TMEFF1 in NB cell lines was significantly higher (P＜0.001). Transient or stable knockdown of TMEFF1 had no significant effect on the proliferation of normal cell lines. However, by knocking down TMEFF1 decreased cell proliferation of SN-K-BE (2) cells as showen RTCA and colony-forming unit assay (P＜0.05). Immunofluorescence results showed that the rate of Ki-67 positive cells was reduced (P＜0.001). CTG results showed that the cell activity was decreased(P＜0.01). Cell scratch assay also showed that the cell migration ratio in the knockdown group was significantly lower than that of control group (P＜0.01). Conclusions TMEFF1 is a protein specifically highly expressed in neuroblastoma. TMEFF1 knockdown has no effect on normal cell lines, but significantly inhibited the proliferation and migration of NB cells, suggesting that TMEFF1 may play an important role in the occurrence and development of neuroblastoma, and so may be a potential target for NB targeting therapy.

Objective To explore the effect of open reading frame 66 (C12ORF66) located at chromosome 12 on the viability of MYCN amplified NB cell lines. Methods DDatasets GSE16476 and GSE49710 in R2 database were analyzed for expression level of C12ORF66 in MYCN amplified and MYCN non-amplified NB cells and its potential correlation with the prognosis of pediatric patients. C12ORF66 mRNA expression level in normal tissue immortalized cell lines, MYCN amplified and MYCN non-amplified cell lines were detected by RT-qRCR. Transient or stable knockdown of C12ORF66 cell lines were constructed to compare the difference in real time cellular analysis (RTCA), colony formation, Ki67 positive cells between the control group and the C12ORF66 knockdown group. Results By analyzing R2 datasets, C12ORF66 level in MYCN amplified samples was significantly higher than that in MYCN non-amplified samples, and the expression of C12ORF66 was negatively correlated with the prognosis of pediatric patients(P＜0.05). C12ORF66 highly expressed in MYCN-amplified BE(2)-C and SK-N-BE(2) cell lines than in MYCN non-amplified CHLA-255 and SH-SY5Y cell lines (P＜0.001). Transient or stable knockdown of C12ORF66 resulted in significant slow down of proliferation of MYCN amplified NB cells (P＜0.001), the colony formation ability was significantly reduced (P＜0.001), and the proportion of Ki67 positive cells was significantly decreased (P＜0.05). Conclusions C12ORF66 was highly expressed in MYCN amplified clinical NB samples and cell lines which is believed to be correlated with poor prognosis of pediatric patients. C12ORF66 knockdown significantly inhibits cell viability of NB cells.

Land use in karst areas affects soil properties, impacting carbon sinks. Accurate estimation of carbon sink flux in karst areas through zoning and classification is crucial for understanding global carbon cycling and climate change. The peak cluster depression is the largest continuous karst landform region in southern China, with the depressions primarily covered by farmland and influenced by agricultural activities. This study focused on the Guancun Underground River Basin, a typical peak cluster depression basin, where sampling and analysis were conducted during the agricultural period of 2021–2022. Using hydrochemical analysis and isotopic methods, the results indicated that: (1) The primary hydrochemical type in the Guancun Underground River Basin is HCO3-Ca, with hydrochemical composition mainly controlled by carbonate rock weathering. (2) The primary sources of Cl−, SO42−, and NO3− are agricultural activities, with agriculture contributing 0.68 mmol/L to dissolved inorganic carbon (DIC), accounting for about 13.86%, as confirmed by ion concentration analysis and isotope verification. (3) The size of the depression area is proportional to the contribution of agricultural activities to DIC, while also being influenced by dilution effects. A comparison was made regarding the contribution of other land use types to DIC. The impact of land use on DIC in karst processes should not be overlooked, and zoning and classification assessments of carbon sink flux under different influencing factors contribute to carbon peaking and carbon neutrality goals. [ABSTRACT FROM AUTHOR]

High‐risk neuroblastoma (HR‐NB) is an aggressive childhood cancer that responds poorly to currently available therapies and is associated with only about a 50% 5‐year survival rate. MYCN amplification is a critical driver of these aggressive tumors, but so far there have not been any approved treatments to effectively treat HR‐NB by targeting MYCN or its downstream effectors. Thus, the identification of novel molecular targets and therapeutic strategies to treat children diagnosed with HR‐NB represents an urgent unmet medical need. Here, we conducted a targeted siRNA screening and identified TATA box‐binding protein‐associated factor RNA polymerase I subunit D, TAF1D, as a critical regulator of the cell cycle and proliferation in HR‐NB cells. Analysis of three independent primary NB cohorts determined that high TAF1D expression correlated with MYCN‐amplified, high‐risk disease and poor clinical outcomes. TAF1D knockdown more robustly inhibited cell proliferation in MYCN‐amplified NB cells compared with MYCN‐non‐amplified NB cells, as well as suppressed colony formation and inhibited tumor growth in a xenograft mouse model of MYCN‐amplified NB. RNA‐seq analysis revealed that TAF1D knockdown downregulates the expression of genes associated with the G2/M transition, including the master cell‐cycle regulator, cell‐cycle‐dependent kinase 1 (CDK1), resulting in cell‐cycle arrest at G2/M. Our findings demonstrate that TAF1D is a key oncogenic regulator of MYCN‐amplified HR‐NB and suggest that therapeutic targeting of TAF1D may be a viable strategy to treat HR‐NB patients by blocking cell‐cycle progression and the proliferation of tumor cells. [ABSTRACT FROM AUTHOR]