MicroRNA-298 determines the radio-resistance of colorectal cancer cells by directly targeting human dual-specificity tyrosine(Y)-regulated kinase 1A.

BACKGROUND: Radiotherapy stands as a promising therapeutic modality for colorectal cancer (CRC); yet, the formidable challenge posed by radio-resistance significantly undermines its efficacy in achieving CRC remission. AIM: To elucidate the role played by microRNA-298 (miR-298) in CRC radio-resistance. METHODS: To establish a radio-resistant CRC cell line, HT-29 cells underwent exposure to 5 gray ionizing radiation that was followed by a 7-d recovery period. The quantification of miR-298 levels within CRC cells was conducted through quantitative RT-PCR, and protein expression determination was realized through Western blotting. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and proliferation by clonogenic assay. Radio-induced apoptosis was discerned through flow cytometry analysis. RESULTS: We observed a marked upregulation of miR-298 in radio-resistant CRC cells. MiR-298 emerged as a key determinant of cell survival following radiation exposure, as its overexpression led to a notable reduction in radiation-induced apoptosis. Intriguingly, miR-298 expression exhibited a strong correlation with CRC cell viability. Further investigation unveiled human dual-specificity tyrosine(Y)-regulated kinase 1A (DYRK1A) as miR-298's direct target. CONCLUSION: Taken together, our findings underline the role played by miR-298 in bolstering radio-resistance in CRC cells by means of DYRK1A downregulation, thereby positioning miR-298 as a promising candidate for mitigating radio-resistance in CRC.

Transcriptome-Wide Identification and Prediction of miRNAs and Their Targets in Paris polyphylla var. yunnanensis by High-Throughput Sequencing Analysis.

Long dormancy period of seeds limits the large-scale artificial cultivation of the scarce Paris polyphylla var. yunnanensis, an important traditional Chinese medicine. Characterizing miRNAs and their targets is crucial to understanding the role of miRNAs during seed dormancy in this species. Considering the limited genome information of this species, we first sequenced and assembled the transcriptome data of dormant seeds and their seed coats as the reference genome. A total of 146,671 unigenes with an average length of 923 bp were identified and showed functional diversity based on different annotation methods. Two small RNA libraries from respective seeds and seed coats were sequenced and the combining data indicates that 263 conserved miRNAs belonging to at least 83 families and 768 novel miRNAs in 1174 transcripts were found. The annotations of the predicted putative targets of miRNAs suggest that these miRNAs were mainly involved in the cell, metabolism and genetic information processing by direct and indirect regulation patterns in dormant seeds of P. polyphylla var. yunnanensis. Therefore, we provide the first known miRNA profiles and their targets, which will assist with further study of the molecular mechanism of seed dormancy in P. polyphylla var. yunnanensis.

[Isolation and identification of Marinobacter adhaerens HY-3 and its allelopathy on Skeletonema costatum].

UNLABELLED: The allelopathy between bacteria and algae is a very complicated physical and ecological phenomenon. A marine bacterium was isolated from the water of a shrimp and crab mix-culturing pond. By 16S rRNA analysis, it was identified as Marinobacter adhaerens HY-3. Skeletonema costatum, a common dominant species of red-tide microorganism in China, was chosen as the other research object. The allelopathic effect of Marinobacter adhaerens HY- 3 on S. costatum was studied. Using the growth mass of Skeletonema costatum and the content of chlorophyll a as the parameters, the effects of HY-3 on the growth and photosynthesis of Skeletonema costatum were studied after co-cultivation and addition of extracellular metabolites of HY-3. The results showed that the growth of S. costatum was inhibited when the concentration of the strain HY-3 was above 10(4), and the growth mass of the 10(4), 10(6) and 10(8) HY-3 group was 70%, 23% and 22% of the control group respectively on the 10th day, with the content of chlorophyll being 88%, 62% and 60% of the control group, respectively. Therefore, the suppression increased with increasing concentration of HY-3. However, addition of extracellular metabolites of HY-3 had no effect on the growth of S. costatum. CONCLUSIONS: M. adhaerens HY-3 had certain allelopathy on S. costatum and affected its growth and photosynthesis. Moreover, interaction between M. adhaerens HY-3 and S. costatum was achieved by their direct contact and the extracellular metabolites did not contain allelopathy factors.

[Analysis on the frequency of urinary iodine in a population-based intervention study].

OBJECTIVE: Through a two-year follow up program, this study was to analyze the urinary iodine frequency of a cohort in the intervention trial, concerning different doses of salt ionization, so as to explore the selection of appropriate concentration of salt ionization. METHODS: A multistage cluster sampling method was used to select three townships in two countries for community intervention with different doses [(15±5) mg/kg, (25±5) mg/kg, (35±5) mg/kg] of salt ionization. RESULTS: After intervention, the median of urinary iodine was reduced among the population. The urinary iodine frequencies of (15±5) mg/kg and (25±5) mg/kg among groups of children were mainly concentrated in 100-200 µg/L and 200-300 µg/L paragraphs in A county. While the 300 µg/L paragraph had an overall decline in B county, the 100 µg/L and 200 µg/L paragraph ratio increased but the trend seemed to be slow. The 100-300 µg/L paragraph of the four treatment groups took a larger proportion and kept smooth in a more ideal state. However, the control group still maintained at above 250 µg/L level. CONCLUSION: The iodine supplementation should be gradually implemented in Chongqing. The doses of salt ionization should be reduced from the current (35±15) mg/kg to (25±5) mg/kg in the economically developed areas. At the same time, we need to continuously follow the changes of the condition.

[Study on the change of urinary iodine of different salt concentrations among the target population in an intervention trial].

OBJECTIVE: To analyze the change of urinary iodine in a cohort of intervention trial and to observe the role of different doses on salt iodization and related impact factors on nutritional condition of iodine. METHODS: Multistage cluster sampling was used to sample three townships in two counties for community intervention with different doses (15 ± 5, 25 ± 5, 35 ± 5) mg/kg. RESULTS: Compared to the (35 ± 5) mg/kg group, the urine iodine levels of three experimental townships were gradually declining in county B when time went on, and the (15 ± 5) mg/kg group showed an obvious results, at 6, 12, 18 and 24 months, with the urine iodine level as 180.00, 186.10, 150.04, 191.28 µg/L respectively, which were in accordance with the WHO standard and reached to appropriate range (187.96 µg/L) at the 18 month. The townships at county Y under intervention had declined slightly, but the urine iodine levels did not reach the WHO standard. The thyroid volume declined from 3.65 ml to 3.40 ml in two counties and the difference between them was statistically significant. CONCLUSION: To some extent, reducing the iodine concentration in salt, had a role of lowering the urine iodine level and reducing the strumous rate.