Importance of ets1 proto-oncogene for breast cancer progression.

Ets proteins are transcription factors, which share a unique DNA binding domain, the Ets domain. Some members of the Ets family are implicated in tumorigenesis. Ets1, the founder of the Ets family, is predominantly expressed in invasive tumors and able to activate certain genes encoding ECM-degrading proteases. We used RNA-interference in combination with DNA chip analysis to identify Ets1-regulated genes in MDA-MB-231 breast cancer cells. Of the Ets1-responsive proteases, matrix metalloproteases MMP1 and MMP9, but not MMP3 or uPA, showed reduced RNA levels when endogenous Ets1 expression was suppressed. These data suggest that Ets1 regulates only a certain subset of ECM-degrading proteases. How Ets1 is regulated in invasive breast cancer cells is unknown. The observations that protein kinase C inhibitors abrogated Ets1 expression and that protein kinase C was able to increase Ets1-dependent transcription imply that protein kinase C is a potential regulator of Ets1 activity in breast cancer cells.

Regulation of the human interleukin-5 promoter by Ets transcription factors. Ets1 and Ets2, but not Elf-1, cooperate with GATA3 and HTLV-I Tax1.

Interleukin-5 (IL-5), expressed primarily by type-2 T helper (Th2) cells, plays an important role in the development of allergic diseases, such as allergic asthma. Studying the regulation of IL-5 gene expression by Ets transcription factors, we found that Ets1 and Ets2, but not Elf-1, were able to activate the human IL-5 promoter in Jurkat T-cells. This required the presence of either phorbol 12-myristate acetate (PMA) plus ionomycin or PMA plus the viral protein HTLV-I Tax1. By mutation studies, it could be shown that Ets1 and Ets2 exerted their effects on the IL-5 promoter through a GGAA motif within the Cle0 element. In myeloid Kasumi cells, Ets1 and Ets2 failed to stimulate IL-5 promoter activity, unless the T-cell specific transcription factor GATA3 was added. These results show, for the first time, that Ets1 and Ets2 are able to cooperate with GATA3. Both ionomycin and Tax1 increased the combined effect of GATA3 with Ets1 and Ets2 in the presence of PMA. The data further demonstrate that, in addition to Ets1, Ets2 is also able to functionally cooperate with Tax1. The synergism of GATA3 with either Ets1 or Ets2 may play an important role in calcium- or Tax1-dependent regulation of IL-5 expression in Th2 cells or in HTLV-I transformed adult T-cell leukemia cells, respectively.

Yunnanxane and its homologous esters from cell cultures of Taxus chinensis var. mairei.

From cell cultures of Taxus chinensis var. mairei, yunnanxane [2 alpha, 5 alpha, 10-beta triacetoxy-14 beta-(2'-methyl-3'-hydroxyl)-butyryloxy-4(20),11-taxadiene, [1], and four new homologous esters, 2 alpha, 5 alpha, 10 beta, 14 beta- tetra-acetoxy-4(20),11-taxadiene [2], 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-propionyloxy-4(20),11-taxadiene [3], 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-isobutyryloxy-4(20),11- taxadiene [4], and 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-(2'-methyl)-butyryloxy-4(20),11- taxadiene [5] have been isolated. Their structures were determined by spectroscopic methods.

Changes in bilirubins in human prenatal development.

1. A densitometric method has been developed for the quantification of azodipyrroles derived from dog bile pigments treated with diazotized ethyl anthranilate. 2. This method was used to estimate the bilirubins in bile and meconium from foetuses of 14-36 weeks gestation. 3. The proportion of the bilirubins in foetal bile changed during gestation. (a) No bile pigments were found until 14 weeks. (b) Between 14 and 15 weeks bilirubin-IX beta was the only bile pigment detected. (c) At 16-17 weeks some unconjugated bilirubin-IX alpha was found in the bile, but up to 20 weeks bilirubin-IX beta was the predominant bilirubin in the bile. (d) At about 20 weeks glucose, xylose, and an unidentified bilirubin-IX alpha monoconjugate were found in the bile. (e) Between 20 and 23 weeks bilirubin-IX alpha glucuronide appeared in the bile. (f) At 30 weeks monoconjugates of bilirubin-IX alpha were the predominant bilirubins in the bile. (g) Only in full-term foetuses was bilirubin-IX alpha monoglucuronide the major bilirubin derivative.

Conjugated and unconjugated bilirubins in humans and rhesus monkeys. Structural identity of bilirubins from biles and meconiums of newborn humans and rhesus monkeys.

1. Bilirubin-IXalpha monoglucuronide was the predominant bilirubin in biles and meconiums of newborn humans and rhesus monkeys. Rhesus-monkey baby biles contained slightly more diglucuronide than did human baby biles. 2. Bilrubin-IXalpha glucoside, bilirubin-IXalpha xyloside and bilirubin-IXbeta were also constituents of human and rhesus-monkey baby biles and meconiums. Bilirubin-IXalpha glucuronide glucoside was present in human and rhesus-monkey baby biles but not in meconiums. The identity of the bilirubins was confirmed by u.v.-visible and mass spectroscopy of the azodipyrroles obtained by treating the bilirubins with diazotized ethyl anthranilate. The resulting azodipyrroles were identical with the corresponding azodipyrroles obtained from human adult biles and also from reduced isomers of biliverdin. 3. Bilirubin-IXbeta was present in much higher proportions in the extracts of meconiums than in the extracts of biles from the same babies. 4. Oxidation of bilirubins to biliverdins occurs in utero to a small but undetermined extent. The resulting green pigments were present in meconiums collected from the lower small and large intestines of newborn babies and rhesus monkeys. 5. Butanol extracted most of the bilirubins present in biles. This modified method proved to be quick and easy. Little hydrolysis of bilirubins took place during extraction or separation by t.l.c.

Conjugated and unconjugated bilirubins in bile of humans and rhesus monkeys. Structure of adult human and rhesus-monkey bilirubins compared with dog bilirubins.

1. Bilirubin-IXalpha, -IXalpha diglucuronide, -IXalpha monoglucuronide, -IXalpha monoglucoside -IXalpha monoxyloside, a bilirubin-IXalpha diconjugate containing glucose and another unknown compound, and bilirubin-IXbeta are present in gall-bladder bile of adult human, rhesus monkey and dog. Dog bile normally also contains other bilirubin-IXalpha diconjugates, i.e. compounds containing two conjugating sugars such as glucuronic acid and glucose, glucuronic acid and xylose and glucose xylose. 2. Azopigments alphaF, alphaO, alpha2, alpha3, betax and delta derived from human and rhesus-monkey bilirubins are identical in their chemical composition with those obtained from the dog. 3. Azopigments alphaF and betax found in diazotized biles of adult humans, rhesus monkeys and dogs are products of unconjugated bilirubin-IXbeta. 4. Technical modifications of previously published procedures [Heirwegh, Fevery, Michiels, Van Hees & Compernolle, (1975) Biochem. J. 145, 185-199] were introduced which make it possible to separate the bilirubins, diazotize the separated bilirubins, extract the azopigments and chromatograph them in one working day (6-8h).

Bile pigments in humans and in nonhuman primates during the perinatal period: composition of meconium and gallbladder bile of newborns and adults.

Meconium of human infants and rhesus monkey infants (Macaca mulatta) contained only about 0.10 of the amount of bilirubin in gallbladder bile of the same individuals. Ninety-nine percent of the bilirubin in adult bile was conjugated. The proportion of conjugated bilirubin in infant bile and meconium was only slightly lower. Adult bile contained more bilirubin disconjugates than monoconjugates, whereas only 20% of the bilirubin in infant bile and meconium was in the form if disconjugates. The predominant azopigment in adult bile was azopigment delta (a glucuronide). Infant bile contained less azopigment delta, more azopigment alpha (azodipyrrole), and a so far unidentified conjugated azopigment (azopigment beta). Azopigment beta was also found in meconium but adult gallbladder bile contained only trace amounts of this pigment.