Role of proteoglycan synthesis genes in osteosarcoma stem cells.

Osteosarcoma stem cells (OSCs) contribute to the pathogenesis of osteosarcoma (OS), which is the most common malignant primary bone tumor. The significance and underlying mechanisms of action of proteoglycans (PGs) and glycosaminoglycans (GAGs) in OSC phenotypes and OS malignancy are largely unknown. This study aimed to investigate the role of PG/GAG biosynthesis and the corresponding candidate genes in OSCs and poor clinical outcomes in OS using scRNA-seq and bulk RNA-seq datasets of clinical OS specimens, accompanied by biological validation by in vitro genetic and pharmacological analyses. The expression of ß-1,3-glucuronyltransferase 3 (B3GAT3), one of the genes responsible for the biosynthesis of the common core tetrasaccharide linker region of PGs, was significantly upregulated in both OSC populations and OS tissues and was associated with poor survival in patients with OS with high stem cell properties. Moreover, the genetic inactivation of B3GAT3 by RNA interference and pharmacological inhibition of PG biosynthesis abrogated the self-renewal potential of OSCs. Collectively, these findings suggest a pivotal role for B3GAT3 and PG/GAG biosynthesis in the regulation of OSC phenotypes and OS malignancy, thereby providing a potential target for OSC-directed therapy.

Effect of aspiration vacuum on the developmental competence of immature human oocytes retrieved using a 20-gauge needle.

In-vitro maturation (IVM) of immature oocytes has been proposed as a potential alternative to conventional IVF treatment following ovarian stimulation. However, the effects of the oocyte retrieval conditions on subsequent development have not been well understood. This study assessed the effects of different aspiration vacuums during oocyte retrieval on the developmental competence of immature oocytes following IVM, IVF and embryo transfer, retrospectively. Immature oocytes were aspirated with 20-gauge needles with a vacuum of 180 or 300 mmHg. Immature oocytes were cultured in IVM medium for 26 h. All mature oocytes were inseminated by intracytoplasmic sperm injection (ICSI). Embryo transfer was carried out 2 or 3 days after ICSI. The percentage of cumulus-cell enclosed oocytes and of transferable embryos per retrieved oocytes in 180 mmHg (69.7% and 23.8%, respectively) were significantly higher (P < 0.01) than those in 300 mmHg (46.2% and 12.8%, respectively). The ongoing pregnancy rate per retrieval cycle in 180 mmHg (30%) was higher (P < 0.01) than that in 300 mmHg (4.3%). The data indicate that lower pressure of vacuum aspiration with a 20-gauge needle improves the developmental competence of immature oocytes following IVM, IVF and embryo transfer.

Successful monozygotic twin delivery following in vitro maturation of oocytes retrieved from a woman with polycystic ovary syndrome: case report.

The incidence of monozygotic twinning (MZT) appears to be increasing within the field of assisted reproductive technology (ART), although the factors contributing to the phenomenon are still far from being identified. On the contrary, in vitro maturation (IVM) of oocytes is becoming more accepted and more and more babies have been born worldwide using this procedure. Assessing its safety and impact on monozygotic twinning (MZT), and following up the health of these babies, is essential. We report here a first case of successful monozygotic (MZ) twin delivery following IVM. The patient was a 28-year-old Japanese female, referred to the IVF clinic for primary infertility. Several previous cycles of ovarian stimulation had resulted in ovarian hyperstimulation syndrome (OHSS). The patient received norethisterone-mestranol to initiate the menstruation, and oocyte retrieval was performed 36 h after hCG. A total of 22 immature oocytes were obtained. Following incubation for 24 h in IVM medium, 50% of the oocytes were matured to the metaphase II (MII) stage. Nine oocytes were fertilized after ICSI with the husband's sperm. Three day 3 embryos were transferred into the uterus on the fourth day following oocyte retrieval. Three weeks after embryo transfer, a single gestational sac was visualized in the uterus. At 7 weeks of gestation, two fetal poles with cardiac activity were seen in the single gestational sac. Serial ultrasound examinations revealed a MZ, monochorionic diamniotic pregnancy. After intensive perinatal monitoring, two healthy male infants were delivered by Caesarean section at 35 weeks of gestation.

Freeze-thaw programmes rescue the implantation of day 6 blastocysts.

The developmental rate of a blastocyst is considered one of the main estimates for evaluating the implantation potential of embryos. Day 6 blastocysts have been reported to be much less viable than day 5 blastocysts. Regarding implantation, the implantation window is advanced due to a background of high sex hormones, and slower growing embryos may not implant because of possible desynchrony with the implantation window. The aim of this study was to investigate the efficacy of cryopreservation of such embryos and subsequent synchronization of embryo transfer with endometrial status. The results of 122 day 6 blastocysts transferred in the clinic were retrospectively examined. Pregnancy rates were compared between the stimulation cycle and hormone replacement cycle in terms of the method of endometrial preparation. Fifty-five day 6 blastocysts were transferred onto the stimulation cycle endometrium in 37 women, resulting in a 5.5% viable pregnancy rate. On the other hand, 67 day 6 blastocysts were transferred onto endometrium prepared by exogenous hormones in 40 women, resulting in a 26.9% viable pregnancy rate (P < 0.01). Consequently, the difference was highly significant. In conclusion, synchronous transfer of slow-growing embryos using the freeze-thaw technique contributes to a positive outcome.