Mass spectrometric identification of candidate RNA-binding proteins associated with Transition Nuclear Protein mRNA in the mouse testis.

Spermatogenesis is a differentiation process that requires dramatic changes to DNA architecture, a process governed in part by Transition Nuclear Proteins 1 and 2 (TNP1 and TNP2). Translation of Tnp1 and Tnp2 mRNAs is temporally disengaged from their transcription. We hypothesized that RNA regulatory proteins associate specifically with Tnp mRNAs to control the delayed timing of their translation. To identify potential regulatory proteins, we isolated endogenous mRNA/protein complexes from testis extract and identified by mass spectrometry proteins that associated with one or both Tnp transcripts. Five proteins showed strong association with Tnp transcripts but had low signal when Actin mRNA was isolated. We visualized the expression patterns in testis sections of the five proteins and found that each of the proteins was detected in germ cells at the appropriate stages to regulate Tnp RNA expression.

Design, synthesis, and SAR of new pyrrole-oxindole progesterone receptor modulators leading to 5-(7-fluoro-3,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-5-yl)-1-methyl-1H-pyrrole-2-carbonitrile (WAY-255348).

We have continued to explore the 3,3-dialkyl-5-aryloxindole series of progesterone receptor (PR) modulators looking for new agents to be used in female healthcare: contraception, fibroids, endometriosis, and certain breast cancers. Previously we reported that subtle structural changes with this and related templates produced functional switches between agonist and antagonist properties ( Fensome et al. Biorg. Med. Chem. Lett. 2002, 12, 3487; 2003, 13, 1317 ). We herein report a new functional switch within the 5-(2-oxoindolin-5-yl)-1 H-pyrrole-2-carbonitrile class of compounds. We found that the size of the 3,3-dialkyl substituent is important for controlling the functional response; thus small groups (dimethyl) afford potent PR antagonists, whereas larger groups (spirocyclohexyl) are PR agonists. The product from our optimization activities in cell-based systems and also for kinetic properties in rodents and nonhuman primates was 5-(7-fluoro-3,3-dimethyl-2-oxo-2,3-dihydro-1 H-indol-5-yl)-1-methyl-1 H-pyrrole-2-carbonitrile 27 (WAY-255348), which demonstrated potent and robust activity on PR antagonist and contraceptive end points in the rat and also in cynomolgus and rhesus monkeys including ovulation inhibition, menses induction, and reproductive tract morphology.

Phase I and pharmacokinetic study of irinotecan in combination with raltitrexed.

PURPOSE: To determine the maximum tolerated dose (MTD) of raltitrexed when given with irinotecan and to evaluate the pharmacokinetics of these two agents when given in combination. METHODS: Patients with advanced solid tumors received irinotecan intravenously over 90 min on days 1 and 8 of each 21-day cycle, with raltitrexed given intravenously over 15 min after irinotecan either on day 1 (cohorts 1-7) or day 2 (cohorts 8-9). The 39 patients received irinotecan and raltitrexed in cohorts of three to six patients at the following dose levels (mg/m(2)): 100/1.0, 100/1.5, 100/2.0, 100/2.5, 100/3.0, 100/3.5, 125/3.0, 75/3.0, 100/3.0. Pharmacologic monitoring of irinotecan and raltitrexed was carried out during cycle 1. RESULTS: A total of 39 patients received irinotecan and raltitrexed in cohorts of three to six patients at nine dose levels. The MTD with dosing of irinotecan on days 1 and 8 and raltitrexed on day 1 was 100 mg/m(2) and 3.0 mg/m(2), respectively, every 21 days, with dose-limiting toxicities (DLTs) of fatigue, neutropenia and diarrhea. When raltitrexed was administered 24 h after irinotecan, these doses exceeded the MTD. No pharmacologic interactions were observed between these agents, and no correlations between pharmacokinetic parameters and toxicity were noted. Of 26 patients with colorectal cancer, 6 had objective partial responses (23%). Four of these patients had previously received a 5-FU-based regimen, two for metastatic disease. CONCLUSIONS: Irinotecan can be safely administered with raltitrexed on a day-1 and day-8 schedule at 100 mg/m(2) and 3.0 mg/m(2), respectively, every 21 days. When raltitrexed was given on day 2, these doses were not tolerated, necessitating a dose reduction of the irinotecan to 75 mg/m(2). This regimen possesses clinical activity in patients with colorectal cancer.