Several recent reports have found a connection between specific aminoacyl-tRNA synthetases and the regulation of angiogenesis. As this new area of research is explored, it is important to have reliable assays to assess the specific angiogenesis functions of these enzymes. This review provides information about specific in vitro and in vivo methods that were used to assess the angiogenic functions of threonyl-tRNA synthetase including endothelial cell migration and tube assays as well as chorioallantoic membrane and tumor vascularization assays. The theory and discussion include best methods of analysis and quantification along with the advantages and limitations of each type of assay.

ObjectiveOur research was carried out to provide a clinical reference for the application of nonsurgical therapy in newborns with congenital auricular deformities in east China.MethodsA retrospective study of consecutive newborns using noninvasive ear molding was conducted in Hangzhou in east China's Zhejiang Province. The demographic and clinical information and photographs of the ear before and after treatment were taken. The diagnosis of each auricular deformity was identified, and the treatment outcome was evaluated.ResultsA total of 224 patients including 356 congenital ear anomalies received noninvasive ear molding. The median age of infants to initiate treatment was 39.5 days. The median treatment duration was 42.5 days. The median follow-up time was 137.0 days. The overall treatment effective rate of all infants with nonoperative ear molding was 92.1%, and mild skin irritation and ulceration occurred in 34 ear deformities (9.6%). It confirmed that the treatment efficiency was satisfactory and the complication rate was still acceptable despite the late initiation treatment of neonates in east China. Further analysis of treatment outcomes among three subgroups of infants (the ages to initiate the ear molding were respectively less than or equal to 28, 29–56, and more than 57 days) revealed that initiation treatment was significantly related to the treatment results and the earlier the initiation treatment, the higher the effective rate and the lower the complication incidence.ConclusionOur study hints that newborns in east China may have a longer period for correction. What is more, although our study affirmed a longer period for noninvasive molding, early diagnosis and treatment are still recommended to improve therapy efficiency and reduce treatment duration and complications.

Despite clear connections between the tumor microenvironment and ovarian cancer invasion, the underlying molecular mechanisms remain elusive. We have recently shown that the protein synthesis regulator threonyl-tRNA synthetase (TARS) has a unique extracellular angiogenic activity separate from its canonical function. Secreted TARS promotes endothelial cell migration and tube formation, and a selective TARS inhibitor, BC194, disrupts normal vessel development in zebra fish and chick embryo models. TARS expression also correlates with tumor stage and angiogenesis in human ovarian cancer. The objective of this study was to validate the biological and clinical relationship between TARS and ovarian tumor progression using a syngenic mouse model of epithelial ovarian cancer. Tumors were initiated by intraperitoneal injection of ID8 mouse ovarian cancer cells, and tumors formed at 4-6 weeks were scored for invasiveness and analyzed by immunostaining for TARS expression and microvascular density. To test the hypothesis that overexpression of TARS promotes invasion, cells were stably transfected with a TARS expression plasmid prior to injection. To test the hypothesis that TARS inhibition reduces tumor invasion, animals harboring ID8 tumors were treated with the high-affinity TARS inhibitor BC194. We found that TARS levels were elevated in ovarian tumors as compared with normal ovarian tissue. Overexpression of TARS in ID8 cells also resulted in enhanced invasiveness and microvascular density of the resulting tumors (p = 0.026). Preliminary results also indicated that inhibition of TARS by BC194 treatment reduced tumor angiogenesis and growth (p = 0.005) without observed toxicities in the animals. Overall, these results show that modifying TARS expression or activity can affect in vivo ovarian tumor angiogenesis and progression. These results encourage further study of TARS as a regulator of the tumor microenvironment and as a possible target for diagnosis and treatment of ovarian cancer. Citation Format: Peibin Wo, Theresa Wellman, Alan Howe, Christopher Francklyn, Karen M. Lounsbury. Non-canonical activity of threonyl-tRNA synthetase promotes angiogenesis and invasion in a mouse model of ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5224. doi:10.1158/1538-7445.AM2015-5224