Simultaneous determination of endogenous retinoic acid isomers and retinol in human plasma by isocratic normal-phase HPLC with ultraviolet detection

Abstract We describe a rapid and simple procedure for the simultaneous quantitation of endogenous 13-cis-retinoic acid, all-trans-retinoic acid, and retinol by isocratic normal-phase HPLC with ultraviolet detection, in 0.5 mL of human plasma. A silica adsorption column was eluted with n-hexane:2-propanol:acetic acid (200:0.7:0.135 by vol) at 0.9 mL/min, and the effluent monitored at 350 nm. The arotinoid ethylsulfonic acid Ro 15-1570 was used as the internal standard. High sensitivity, allowing quantitation of physiological concentrations, was achieved, particularly for the retinoic acid isomers. The detection limits were 0.5 microgram/L in plasma for both 13-cis- and trans-retinoic acid, and 10 micrograms/L for retinol. The CVs for between-day determinations of the lowest quality-control concentration (n = 12) were 4.8% for 13-cis-retinoic acid, 3.4% for trans-retinoic acid, and 3.0% for retinol. The mean (+/- SD) concentrations of 13-cis-retinoic acid (1.79 +/- 0.56 microgram/L), trans-retinoic acid (1.35 +/- 0.42 microgram/L), and retinol (533 +/- 58 micrograms/L) measured in plasma from 22 healthy volunteers agreed well with those previously reported.

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Characterization of acute promyelocytic leukemia cases with PML-RAR alpha break/fusion sites in PML exon 6: identification of a subgroup with decreased in vitro responsiveness to all-trans retinoic acid

Blood ◽

10.1182/blood.v86.4.1540.bloodjournal8641540 ◽

1995 ◽

Vol 86 (4) ◽

pp. 1540-1547 ◽

Cited By ~ 77

Author(s):

RE Gallagher ◽

YP Li ◽

S Rao ◽

E Paietta ◽

J Andersen ◽

...

Keyword(s):

Retinoic Acid ◽

Acute Promyelocytic Leukemia ◽

High Sensitivity ◽

Promyelocytic Leukemia ◽

Reaction Products ◽

Reading Frame ◽

Trans Retinoic Acid ◽

All Trans Retinoic Acid ◽

Fusion Site

Of 113 acute promyelocytic leukemia cases documented to have diagnostic PML-RAR alpha hybrid mRNA, 10 cases (8.8%) had fusion sites in PML gene exon 6 (V-forms) rather than in the two common hybrid mRNA configurations resulting from breaksites in either PML gene intron 6 (L- forms) or intron 3 (S-forms). In 4 V-form cases, a common break/fusion site was discovered at PML gene nucleotide (nt) 1685, abutting a 3′ cryptic splice donor sequence. The fusion site was proximal to the common site in 1 case and more distal in 5 cases. The open reading frame encoding a PML-RAR alpha gene was consistently preserved, either by an in-frame fusion site or by the insertion of 3 to 127 unidentified nts. In 2 V-form cases, hybridization analysis of the reverse transcriptase-polymerase chain reaction products with a PML-RAR alpha juction probe was required for discrimination from L-form cases. Two V- form subgroups were defined by in vitro sensitivity to all-trans retinoic acid (tRA)-induced differentiation: 4 of 4 cases tested with fusion sites at or 5′ to nt 1685 (subgroup E6S) had reduced sensitivity (EC50 > or = 10(-7) mol/L), whereas 4 of 4 cases with fusion sites at or 3′ to nt 1709 (subgroup E6L) had high sensitivity (EC50 < 10(-8) mol/L) indistinguishable from that of L-form and S-form cases. These results provide the first link between PML-RAR alpha configuration and tRA sensitivity in vitro and support the importance of subclassifying APL cases according to PML-RAR alpha transcript type.

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