Differentiation of neonate mouse spermatogonia on two-dimensional and three-dimensional culture systems supplemented with d-Serine and Dizocilpine (MK-801)

N-methyl-d-aspartate (NMDA) modulates the spermatogenesis process through stimulating the steroid hormone biosynthesis. The aim of this study was to evaluate the effects of NMDA receptors agonists (d-Serine) and antagonists (MK801) on spermatogonia differentiation on decellularization testicular matrix (DTM) hydrogel scaffold. Four treatment groups were planned: 2D + D-Serine, 3D + D-Serine, 2D + MK801, and 3D + MK801. Results showed that cell viability was significantly decreased after 48 h in the 3D + D-Serine group and after 24 and 48 h in the 3D + MK801 group compared to the controls. The spermatogonia proliferation after two, four, and eight weeks was significantly increased in the 3D + D-Serine culture, while it was significantly reduced in the 2D + MK801 and 3D + MK801 groups after four and eight weeks. Real-time PCR results demonstrated that pre-meiotic gene (Plzf) expression was significantly increased only in the 3D + D-Serine culture compared to the control groups after four weeks of culture. The meiotic gene (Sycp3) expression was significantly increased in the 2D + D-Serine and 3D + D-Serine compared to the 2D controls after four and eight weeks. The post-meiotic gene (Tnp1) level in the 3D + D-Serine was significantly higher than the other groups. Flow-cytometry results indicated that the protein expression of Plzf (after four and eight weeks), Sycp3 (after eight weeks), and Tnp1 (after eight weeks) in the d-Serine-treated groups was significantly increased compared with the 2D control groups. There were not any significant changes in the gene expression of spermatogenic-related markers in MK801 culture media. However, a significant decrease in the protein levels of Plzf after eight weeks and Sycp3 after four and eight weeks was observed. In conclusion, the addition of NMDARs agonists (d-Serine) could be used to regulate the differentiation of spermatogonia in the 3D culture system.

A Novel Collagen Dot Assay for Monitoring Cancer Cell Migration

Cell migration is a critical determinant of cancer invasion and metastasis. Drugs targeting cancer cell migration have been hindered due to the lack of effective assays for monitoring cancer cell migration. Here we describe a novel method to microscopically monitor cell migration in a quantitative fashion. This assay can be used to study genes involved in cancer cell migration, as well as screening anticancer drugs that target this cellular process.

Observation of ovarian cancer stem cell behavior and investigation of potential mechanisms of drug resistance in three-dimensional cell culture

Cancer cells behave differently in a three-dimensional (3D) cell culture compared with in the conventional two-dimensional (2D) one. Accumulated evidences indicate that the characteristics of cancer stem cells (CSCs) are different from common cancer cells due to their ability to produce tumors and resist chemoradiation. The objective of this work was to observe CSC behavior and investigate the potential mechanisms of CSC drug resistance in 3D versus 2D in vitro environment. We first demonstrated that the CD44(+)CD117(+)cells isolated from the human epithelial ovarian cancer HO8910 cell line have the properties of CSCs that revealed faster growth, larger tumorsphere and stronger survival potential in the hypoxic environment in 3D cell culture as well as more powerful tumorigenicity in a xenograft mice than the HO8910 cells. The CD44(+)CD117(+)CSCs also exhibited high chemoresistance to anticancer drugs when the cells were incubated with 5-fluorouracil, cisplatin and carboplatin, respectively in 3D versus 2D environment. This might be associated with the high expression of ABCG2, ABCB1 and the high expression of MMP-2 and MMP-9 in CD44(+)CD117(+)CSCs. Overall, these results suggest the advantages of using 3D culture model to accurately display CSC behavior in vitro. 3D model may improve the efficacy of screening anticancer drugs for treatment of ovarian CSCs.