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Full-Text Articles in Life Sciences

Role Of Stat3/5 And Bcl-2/Xl In 2-Methoxyestradiol-Induced Endoreduplication Of Nasopharyngeal Carcinoma Cells, Cm Ting, Ck Wong, Rn Wong, Kw Lo, Aw Lee, Gs Tsao, Ml Lung, N.K. Mak Dec 2010

Role Of Stat3/5 And Bcl-2/Xl In 2-Methoxyestradiol-Induced Endoreduplication Of Nasopharyngeal Carcinoma Cells, Cm Ting, Ck Wong, Rn Wong, Kw Lo, Aw Lee, Gs Tsao, Ml Lung, N.K. Mak

Professor MAK, Nai Ki

2-methoxyestradiol (2ME2), an endogenous metabolite of 17-b-estradiol, has been shown to induce apoptosis and cell cycle arrest in various tumor models. We have previously shown that 2ME2 induced endoreduplication in a welldifferentiated nasopharyngeal carcinoma (NPC) HK-1 and a poorly differentiated C666-1 cell line. In the present study, we studied the survival factors involved in 2ME2-induced endoreduplicating NPC cells. In the HK-1 cells, knockdown of BcL-xL expression by siRNA resulted in the reduction of endoreduplication and an increase in the percentage of apoptosis. Further mechanistic study revealed that 2ME2 enhanced the expression of the phosphorylated form of STAT5 (p-STAT5-Y694), but not …


Molecular Anatomy Of The Developing Limb In The Coqu ́I Frog, Eleutherodactylus Coqui, Joshua Gross, Ryan Kerney, James Hanken, Clifford Tabin Dec 2010

Molecular Anatomy Of The Developing Limb In The Coqu ́I Frog, Eleutherodactylus Coqui, Joshua Gross, Ryan Kerney, James Hanken, Clifford Tabin

Ryan Kerney

The vertebrate limb demonstrates remark- able similarity in basic organization across phylogenetically disparate groups. To gain further insight into how this mor- phological similarity is maintained in different developmental contexts, we explored the molecular anatomy of size-reduced embryos of the Puerto Rican coqu ́ı frog, Eleutherodactylus coqui. This animal demonstrates direct development, a life- history strategy marked by rapid progression from egg to adult and absence of a free-living, aquatic larva. Nonethe- less, coqu ́ı exhibits a basal anuran limb structure, with four toes on the forelimb and five toes on the hind limb. We in- vestigated the extent to …


Levels Of Biological Organization And The Origin Of Novelty, Brian Hall, Ryan Kerney Dec 2010

Levels Of Biological Organization And The Origin Of Novelty, Brian Hall, Ryan Kerney

Ryan Kerney

The concept of novelty in evolutionary biology pertains to multiple tiers of biological organization from behavioral and morphological changes to changes at the molecular level. Identifying novel features requires assessments of similarity (homology and homoplasy) of relationships (phylogenetic history) and of shared developmental and genetic pathways or networks. After a brief discussion of how novelty is used in recent literature, we discuss whether the evolutionary approach to homology and homoplasy initially formulated by Lankester in the 19th century informs our understanding of novelty today. We then discuss six examples of morphological features described in the recent literature as novelties, and …


Embryonic Staging Table For A Direct- Developing Salamander, Plethodon Cinereus (Plethodontidae), Ryan Kerney Dec 2010

Embryonic Staging Table For A Direct- Developing Salamander, Plethodon Cinereus (Plethodontidae), Ryan Kerney

Ryan Kerney

This work presents a refined staging table for the direct-developing red-backed salamander Plethodon cinereus, which is based on the incom- plete staging system of James Norman Dent (J Morphol 1942; 71:577– 601). This common species from eastern North America is a member of the species-rich lungless salamander family Plethodontidae. The stag- ing table presented here covers several stages omitted by Dent and reveals novel developmental features of P. cinereus embryos. These include putative Leydig cells and open gill clefts, which are found in lar- vae of metamorphosing species but were previously reported as absent in direct-developing Plethodon. Other features found …