A cytotoxic, apoptotic, low-molecular weight factor from pineal gland.
Previous studies suggest that the pineal gland may play a role in tumour growth inhibition. In this respect, melatonin, as the major hormone of this gland, has been extensively studied. However, there is growing evidence for the existence of other yet unknown pineal factors that may have tumour growth inhibiting properties. Here we describe the partial purification of a highly cytotoxic low molecular weight (<400 Da) hydrophilic fraction (designated F2M3R), starting from a porcine pineal extract (PE), via methanol precipitation followed by reverse-phase HPLC. F2M3R is cytotoxic for a highly apoptosis-resistant human erythroleukemia cell line (K562) at a concentration as low as 30 microg/ml. The viability of the cells was not influenced by an identical prepared porcine pituitary extract or by melatonin. PE induces apoptosis in K562 cells as indicated by three different criteria: morphology, in situ TUNEL assay and bi-parametric FACS analysis with annexin V and propidium iodide, but does not influence the viability of stimulated peripheral blood mononuclear cells. These observations warrant further purification and validation of the cytotoxicity in a panel of different human tumour and non-malignant cells.
Catrina
S B
SB
Dept. of Endocrinology II, University of Medicine and Pharmacy Carol Davila, Bucharest, Romania.
Catrina
A I
AI
Sirzén
F
F
Griffiths
W
W
Bergman
T
T
Biberfeld
P
P
Coculescu
M
M
Mutt
V
V
D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D001685:Biological Factors / Q000302:isolation & purification / Q000494:pharmacology*; D002469:Cell Separation; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D005434:Flow Cytometry; D006801:Humans; D020287:In Situ Nick-End Labeling; D020014:K562 Cells / Q000187:drug effects* / Q000473:pathology; D008970:Molecular Weight; D009000:Monocytes / Q000187:drug effects; D010870:Pineal Gland / Q000737:chemistry*; D011419:Propidium / Q000378:metabolism; D013552:Swine; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism
D017304:Annexin A5; D001685:Biological Factors; D013778:Tetrazolium Salts; D013844:Thiazoles; D011419:Propidium; C022616:thiazolyl blue