Community-level risk assessments on organophosphate esters in the sediments from the Bohai Sea of China based on multimodal species sensitivity distributions coupled with the equilibrium partitioning method.

Organophosphate esters (OPEs), increasingly used as alternatives to brominated flame retardants, are ubiquitous in the global aquatic environment. Despite their potential toxicological impact on ecosystems, community-level risk assessments for OPEs in sediments remain scarce. This study investigated OPE occurrences and composition characteristics in the Bohai Sea's sediments and appraised both individual and joint ecological risks posed by characteristic OPE homologs using ten commonly used species sensitivity distribution (SSD) models, integrating acute-to-chronic conversion and phase equilibrium partitioning. OPEs were detected across all sediment samples, with total concentrations ranging from 0.213 ng/g dry weight (dw) to 91.1 ng/g dw. The predominant congeners included tri-n-butyl phosphate (TnBP), triisobutyl phosphate (TiBP), tri(2-ethylhexyl) phosphate, tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(1, 3-dichloro-2-propyl) phosphate (TDCIPP), and triphenylphosphine oxide. Best-fit SSD models varied among TnBP, TiBP, TCEP, TCPP, and TDCIPP, demonstrating Sigmoid, Burr III, Sigmoid, Burr III, and Burr III, respectively. The same parametric model demonstrated variability in the fitting process for different OPE congeners, which also happened to the fitting results of ten parametric models for the same specific characteristic congener, underscoring the necessity of employing multiple models for precise community-level risk assessments. Hazard concentrations for a 5% cumulative probability were 0.116 mg/L, 2.88 mg/L, 1.30 mg/L, 1.44 mg/L, and 1.85 mg/L for each respective congener. The resulting risk quotients (RQ) and overall hazard index (HI) were selected as criteria to assess the individual and joint ecological risks of OPEs in sediments from the Bohai Sea, respectively. RQ and HI were both below 0.1, indicating a low risk to the local ecosystems. Multi-model SSD analysis could provide refined data for community-level risk evaluation, offering valuable insights for the development of evidence-based environmental standards and pollution control strategies.

[Expression of miR-143 in nasopharyngeal carcinoma cell lines and its effect on cell adhesion ability].

OBJECTIVE: To detect miR-143 expression in human nasopharyngeal carcinoma (NPC) cell lines and explore the role of miR-143 in regulating the adhesion ability of NPC cells. METHODS: Fluorescence quantitative RT-PCR was used to detect miR-143 expression levels in 5 NPC cell lines (CEN1, CNE2, HONE1, 5-8F, and 6-10B) and an immortalized human nasopharyngeal epithelial cell line (NP69). The retrovirus plasmid pMSCV-puro-miR-143 was constructed and the packaged retroviruses pMSCV-puro and pMSCV-puro-miR-143 were infected in 5-8F cells to establish a cell line with stable miR-143 overexpression, whose adhesion ability was tested with adhesion assay. RESULTS: The expression of miR-143 was down- regulated in the NPC cell lines, and the highly metastatic NPC cell line 5-8F had a expression of only 3.0% of the control level, as compared with the level of 63.59% in the tumorigenic but nonmetastatic NPC cell line 6-10B. The transfected 5-8F cells showed a 1080-fold increase of miR-143 expression (P<0.05) with a significantly lowered adhesion ability. CONCLUSION: miR-143 plays a role in regulating the invasiveness and metastasis of NPC, and overexpression of miR-143 causes a significant reduction of the adhesion ability of the highly metastatic NPC cell line 5-8F.

[Role of centromere protein H in human gastric cancer cell proliferation].

OBJECTIVE: To explore the role of centromere protein H (CENP-H) in the proliferation of human gastric cancer cells. METHODS: RT-PCR and Western blot analysis were employed to examine the mRNA and protein expressions of CENP-H in 7 human gastric cancer cell lines and immortalized human gastric epithelial cells (GES-1). The cells were infected with the retrovirus vectors pMSCV-CENP-H or CENP-H-RNAi to establish stable cell lines with high CENP-H expression or CENP-H expression interference. MTT assay and colony formation assay were used to examine the changes in the cell proliferation after the infection. RESULTS: CENP-H was over-expressed in gastric cancer cell lines AGS, BGC823, SGC-7901, MKN45, HGC27, MGC-803 and MKN28 at both mRNA and protein levels. The established AGS/CENP-H cell line with increased CENP-H expression showed enhanced proliferative activity, while the cell line MGC-803/CENP-H-RNAi with CENP-H expression interference showed an obviously lowered proliferation ability. CONCLUSION: CENP-H promotes the proliferation of human gastric cancer cells, suggesting its important role in the occurrence and development of gastric cancer.

[Cloning of hsa-miR-148a and construction of its retroviral expression vector].

OBJECTIVE: To clone hsa-miR-148a and construct its retroviral expression vector. METHODS: The pre-miR-148a amplified by PCR was inserted to pMSCV to construct the recombinant retroviral expression plasmid pMSCV-miR-148a, which was confirmed by restriction endonuclease analysis and DNA sequencing. The retroviral expression vector pMSCV-miR-148a and PIK packaging plasmid were cotransfected into 293FT packaging cells by calcium phosphate-mediated transfection to produce the retrovirus, and the retrovirus titer was measured by infection of NIH3T3 cells. RESULTS: Restriction enzyme digestion and DNA sequencing demonstrated that the retroviral vector pMSCV-miR-148a was constructed successfully, and the virus titer was 5x10(8) CFU/ml after infection of NIH3T3 cells. CONCLUSION: The successful construction of the retroviral expression vector MSCV-miR-148a allows the production of high-titer retrovirus to facilitate further study of the molecular functions of miR-148a.