Comparative metabolomics of MCF-7 breast cancer cells using different extraction solvents assessed by mass spectroscopy.

Metabolic profiling of cancer cells can play a vital role in revealing the molecular bases of cancer development and progression. In this study, gas chromatography coupled with mass spectrometry (GC-MS) was employed for the determination of signatures found in ER+/PR+ breast cancer cells derived from MCF-7 using different extraction solvents including: A, formic acid in water; B, ammonium hydroxide in water; C, ethyl acetate; D, methanol: water (1:1, v/v); and E, acetonitrile: water (1:1, v/v). The greatest extraction rate and diversity of metabolites occurs with extraction solvents A and E. Extraction solvent D showed moderate extraction efficiency, whereas extraction solvent B and C showed inferior metabolite diversity. Metabolite set enrichment analysis (MSEA) results showed energy production pathways to be key in MCF-7 cell lines. This study showed that mass spectrometry could identify key metabolites associated with cancers. The highest enriched pathways were related to energy production as well as Warburg effect pathways, which may shed light on how energy metabolism has been hijacked to encourage tumour progression and eventually metastasis in breast cancer.

Quick and Sensitive UPLC-ESI-MS/MS Method for Simultaneous Estimation of Sofosbuvir and Its Metabolite in Human Plasma.

A simple, fast and highly sensitive RP-UPLC-MS/MS method was developed and validated for the simultaneous determination of sofosbuvir (SR) and its metabolite GS331007 in human plasma using ketotifen as an internal standard (IS). The separation was achieved on Acquity UPLC BEH C18 (50 × 2.1 mm, i.d. 1.7 µm, Waters, USA) column using acetonitrile:5 mM ammonium formate:0.1% formic acid (85:15:0.1% v/v/v) as a mobile phase at a flow rate of 0.35 mL/min in an isocratic elution. The Xevo TQD UPLC-MS/MS was operated under the multiple-reaction monitoring mode using positive electrospray ionization. Extraction with dichloromethane was used in the sample preparation. Method validation was performed as per the Food and Drug Administration (FDA) guidelines and the calibration curves of the proposed method were found to be linear in the range of 1-1000 ng/mL for SR and in the range of 10-1500 ng/mL for its metabolite (GS331007) with an elution time of 1.83 min. All validation parameters were within the acceptable range according to the bioanalytical methods validation guidelines. Furthermore, the obtained results of matrix effects indicate that ion suppression or enhancement from human plasma components was negligible under the optimized conditions. The proposed method can be applied in high-throughput analysis required for pharmacokinetic and bioequivalence studies in human samples.

Enantioseparation of Synthetic Cathinones Enantiomers with Tertiary Amine Structure in Urine and Plasma.

A sensitive and selective method for detection and quantitation of the enantiomers of 18 synthetic cathinones with tertiary amine structure using HPLC-UV-VIS has been developed. Two chiral columns, Astec Cellulose DMP and Amylose-based Chiralpak AS-H, have been examined separately. Mobile phase composed of hexane, isopropanol and triethylamine (99.0:1.0:0.1) was used under an isocratic elution mode. Three of these compounds were separated simultaneously after being spiked into urine and plasma samples. 2,3-Methylenedioxy pyrovalerone was used as an internal standard for the purpose of quantitation. The analytical method has been validated in terms of linearity, limits of detection (LOD), limits of quantitation (LOQ), recoveries and reproducibilities in urine and plasma matrices. The calibration curves exhibited correlation coefficients better than 0.99. It was found that the LODs of these cathinone derivatives in urine were in the range of 1.00-1.47 ppm; while in plasma, the LODs were in the range of 0.14-0.67 ppm. The LOQs in urine were in the range of 3.03-4.46 ppm and in plasma they were in the range of 0.42-2.04 ppm. The method recoveries in terms of percent error averaged 2.4% and 3.2% for the spiked plasma and urine samples, respectively; while interday and intraday reproducibilities reported at three different levels, 5, 100 and 200 ppm, in terms of coefficient of variance were in the range of (0.27-5.39)% in plasma and (0.47-3.12)% in urine which lies in the acceptable range.

Quantitative determination of doxorubicin in the exosomes of A549/MCF-7 cancer cells and human plasma using ultra performance liquid chromatography-tandem mass spectrometry.

In cancer therapy, exosomes efflux enhances resistance of cancer cells toward anticancer agents through mediating the transport of anticancer drugs outside the cells. In this study, a rapid, simple and highly sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the determination of Doxorubicin (DOX) in exosomes of cancer cells and human plasma using Ketotifen as an internal standard (IS). Plasma samples spiked with DOX and two cancer cell lines (A549 & MCF-7) were incubated with different concentrations of DOX and IS. The analytes were then extracted with methanol after protein precipitation and the chromatographic separation was carried out using a C18 column, with a mixture of acetonitrile-water- formic acid (85:15:0.1%, v/v/v) as mobile phase. Multiple reaction monitoring (MRM) was utilized to monitor the protonated precursor to product ion transitions of m/z 544.25 > 397.16 and m/z 310.08 > 96.97 for the quantification of DOX and IS, respectively. The method was linear over ranges of 1-1000 ng/mL for DOX in plasma and 2-1000 ng/mL for DOX in exosome samples. The lower limit of quantification of this method was 1 ng/mL, 2 ng/mL and 2 ng/mL in human plasma, A549 & MCF-7 cells respectively. Intra- and inter day precision of all quality control concentrations were less than 10.33% and the accuracy values ranged from -4.82 to 12.60%. The optimized UPLC-MS/MS method proved to be fast, specific, simple and highly sensitive and was successfully applied for the estimation of DOX in the exosomes of cancer cells and plasma.