The ZIP6/ZIP10 heteromer is essential for the zinc-mediated trigger of mitosis.

Zinc has been known to be essential for cell division for over 40 years but the molecular pathways involved remain elusive. Cellular zinc import across biological membranes necessitates the help of zinc transporters such as the SLC39A family of ZIP transporters. We have discovered a molecular process that explains why zinc is required for cell division, involving two highly regulated zinc transporters, as a heteromer of ZIP6 and ZIP10, providing the means of cellular zinc entry at a specific time of the cell cycle that initiates a pathway resulting in the onset of mitosis. Crucially, when the zinc influx across this heteromer is blocked by ZIP6 or ZIP10 specific antibodies, there is no evidence of mitosis, confirming the requirement for zinc influx as a trigger of mitosis. The zinc that influxes into cells to trigger mitosis additionally changes the phosphorylation state of STAT3 converting it from a transcription factor to a protein that complexes with this heteromer and pS38Stathmin, the form allowing microtubule rearrangement as required in mitosis. This discovery now explains the specific cellular role of ZIP6 and ZIP10 and how they have special importance in the mitosis process compared to other ZIP transporter family members. This finding offers new therapeutic opportunities for inhibition of cell division in the many proliferative diseases that exist, such as cancer.

Recombinant versus urinary gonadotrophin for ovarian stimulation in assisted reproductive technology cycles.

BACKGROUND: Several systematic reviews compared recombinant gonadotrophin with urinary gonadotrophins (HMG, purified FSH, highly purified FSH) for ovarian hyperstimulation in IVF and ICSI cycles and these reported conflicting results. Each of these reviews used different inclusion and exclusion criteria for trials. Our aim in producing this review is to bring together all randomised studies in this field under common inclusion criteria with consistent and valid statistical methods. OBJECTIVES: To compare the effectiveness of recombinant gonadotrophin (rFSH) with the three main types of urinary gonadotrophins (i.e. HMG, FSH-P and FSH-HP) for ovarian stimulation in women undergoing IVF or ICSI treatment cycles. SEARCH STRATEGY: An extended search was done according to Cochrane guidelines including the Menstrual Disorders & Subfertility Group's Specialised Register of controlled trials, The Cochrane Central Register of Controlled Trials, MEDLINE (1966 to May 2010), EMBASE (1980 to May 2010), CINAHL (1982 to May 2010), National Research Register, and Current Controlled Trials. SELECTION CRITERIA: All randomised controlled trials reporting data comparing clinical outcomes for women undergoing IVF/ICSI cycles and using recombinant FSH in comparison with HMG or highly purified HMG, purified urinary FSH (FSH-P), and highly purified urinary FSH (FSH-HP) for ovarian hyperstimulation in IVF or ICSI cycles were included. DATA COLLECTION AND ANALYSIS: Primary outcome measure was live birth rate and OHSS per randomised woman.Binary outcomes were analysed using odds ratios and also reported in absolute terms. Grouped analyses were carried out for all outcomes to explore whether relative effects differed due to key features of the trials. MAIN RESULTS: We included 42 trials with a total of 9606 couples. Comparing rFSH to any of the other gonadotrophins irrespective of the down-regulation protocol used, did not result in any evidence of a statistically significant difference in live birth rate (28 trials, 7339 couples, odds ratio 0.97, 95% CI 0.87 to 1.08). This suggests that for a group with a 25% live birth rate using urinary gonadotrophins the rate would be between 22.5% and 26.5% using rFSH. There was also no evidence of a difference in the OHSS rate (32 trials, 7740 couples, OR 1.18, 95% CI 0.86 to 1.61). This means that for a group with 2% risk of OHSS using urinary gonadotrophins, the risk would be between 1.7% and 3.2% using rFSH. AUTHORS' CONCLUSIONS: Clinical choice of gonadotrophin should depend on availability, convenience and costs. Further research on these comparisons is unlikely to identify substantive differences in effectiveness or safety.