[Rapid Identification of Chemical Components in Polygonum multiflorum Formula Granules by UPLC/Q-TOF MS].

OBJECTIVE: To establish a simple and reliable method for rapid separation and identification of chemical components in Polygonum multiflorum Formula Granules. METHODS: An ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometric method( UPLC/Q-TOF MS) was used. The separation was performed on an Agilent Eclipse Plus C18 RRHD(100 mm x 2.1 mm, 1.8 µm) column with a mobile phase of water and acetonitrile in a gradient elution mode. The flow rate was 0.4 mL/min and the column temperature was maintained at 25 degrees C. TOF MS was applied for qualitative analysis under positive ion mode. RESULTS: Five compounds were identified by the time of flight mass spectrometry and literature data. CONCLUSION: This method is accurate, rapid and sensitive, it can provide reference for the quality control of Polygonum multiflorum Formula Granules.

[Establishing quantitative model of naringin in citrus Grandis Exocarpium by near infrared spectroscopy].

OBJECTIVE: To establish the quantitative model of naringin in Citrus Grandis Exocarpium by near infrared reflectance spectroscopy(NIRS). METHODS: NIRSs of 54 Citrus Grandis Exocarpium samples were collected and pretreated by TQ Analyst 8.0 software with first derivative + Norris filter. The wavebands in 10,000-4000 cm(-1) were collected and 9 numbers of factors were used. The calibration model was built with partial least squares (PLS). RESULTS: The quantitative calibration model had good correlation coefficients (r = 0.9927) and low root mean square error of calibration (RMSEC = 0.0746). Root mean square error of prediction (RMSEP) was 0.282. The average rate of recovery of validation was 101.65% (n = 9). CONCLUSION: The quantitative calibration model is trustworthy and it can be used to predict naringin in Citrus Grandis Exocarpium accurately. This simple, fast and non-destructive advantages of NIRS can be used for quality control and exploitation of Citrus Grandis Exocarpium.

Detection of miR-92a and miR-21 in stool samples as potential screening biomarkers for colorectal cancer and polyps.

OBJECTIVE: The detection of molecular markers in stool samples is a potential strategy for colorectal cancer (CRC) screening. This study evaluated the feasibility of detecting miR-21 and miR-92a in stool samples of patients with CRC or polyps. METHODS: The reproducibility of detection and stability of stool-based microRNA were evaluated. Stool samples were collected from 88 patients with CRC, 57 patients with colorectal polyps and 101 healthy controls. MiRNA levels in CRC tissues and stool samples were detected by real-time quantitative reverse transcription PCR. Stool miR-21 and miR-92a levels were compared before and after the removal of tumour or advanced adenoma. RESULTS: The study demonstrated that stool-based miRNA were stable with highly reproducible detection. The expression of miR-21 and miR-92a was significantly higher in CRC tissues compared with their adjacent normal tissues (p<0.0001). Patients with CRC had a significantly higher stool miR-21 level (p<0.01) and miR-92a level (p<0.0001) compared with normal controls. Stool miR-92a, but not miR-21, was significantly higher in patients with polyps than in controls (p<0.0001). At a cut-off value of 435 copies/ng of stool RNA, miR-92a had a sensitivity of 71.6% and 56.1% for CRC and polyp, respectively, and a specificity of 73.3%. In addition, the stool miR-92a level demonstrated a higher sensitivity for distal CRC than proximal CRC (p<0.05), and a higher sensitivity for advanced adenoma than minor polyps (p<0.05). Removal of tumour resulted in reduced stool miR-21 and miR-92a levels (p<0.01), and the removal of advanced adenoma resulted in a reduction of the stool miR-92a level (p<0.05). CONCLUSION: Stool miRNA are useful for screening CRC and polyps.

MicroRNA-18a attenuates DNA damage repair through suppressing the expression of ataxia telangiectasia mutated in colorectal cancer.

BACKGROUND: miR-18a is one of the most up-regulated miRNAs in colorectal cancers (CRC) based on miRNA profiling. In this study, we examined the functional significance of miR-18a in CRC. METHODS: Expression of miR-18a was investigated in 45 CRC patients. Potential target genes of miR-18a were predicted by in silico search and confirmed by luciferase activity assay and Western blot. DNA damage was measured by comet assay. Gene function was measured by cell viability, colony formation and apoptosis assays. RESULTS: The up-regulation of miR-18a was validated and confirmed in 45 primary CRC tumors compared with adjacent normal tissues (p<0.0001). Through in silico search, the 3'UTR of Ataxia telangiectasia mutated (ATM) contains a conserved miR-18a binding site. Expression of ATM was down-regulated in CRC tumors (p<0.0001) and inversely correlated with miR-18a expression (r = -0.4562, p<0.01). Over-expression of miR-18a in colon cancer cells significantly reduced the luciferase activity of the construct with wild-type ATM 3'UTR but not that with mutant ATM 3'UTR, inferring a direct interaction of miR-18a with ATM 3'UTR. This was further confirmed by the down-regulation of ATM protein by miR-18a. As ATM is a key enzyme in DNA damage repair, we evaluated the effect of miR-18a on DNA double-strand breaks. Ectopic expression of miR-18a significantly inhibited the repair of DNA damage induced by etoposide (p<0.001), leading to accumulation of DNA damage, increase in cell apoptosis and poor clonogenic survival. CONCLUSION: miR-18a attenuates cellular repair of DNA double-strand breaks by directly suppressing ATM, a key enzyme in DNA damage repair.