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S Fan

Publications and source records attributed to S Fan.

167 records · Page 10Linked to original sources
PubMedDate not supplied

A deletion affecting several gene candidates is present in the Evergrowing peach mutant.

Evergrowing (EVG) peach is one of only two described mutants affecting winter dormancy in woody perennial species. EVG peach does not set terminal buds, cease new leaf growth, nor enter into a dormant resting phase in response to winter conditions. The EVG mutation segregates in F2 progeny as a single recessive nuclear gene. A local molecular genetic linkage map around EVG was previously developed using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers, and a bacterial artificial chromosome (BAC) contig that contains the EVG mutation was assembled. A MADS box coding open reading frame (ORF) was found in a BAC of this contig and used as a probe. The probe detected a polymorphism between the wild-type and mutant genomes, and the polymorphism is indicative of a deletion in EVG peach. The EVG gene region contained six potential MADS-box transcription factor sequences, and the deletion in EVG affected at least four of these. The deletion was bracketed using RFLP analysis, which showed that it is contained within a segment of the genome no greater than 180 kb.

Base Sequence↗
PubMedDate not supplied

Cellular effects of olomoucine in human lymphoma cells differing in p53 function.

Olomoucine, a purine derivative, inhibits multiple cyclin-dependent kinases that play important roles in regulating the G1/S and G2/M transitions of the cell cycle. In this study we investigated the cellular effects of olomoucine in two human Burkitt's lymphoma cell lines, WMN (containing wild-type p53) and CA46 (containing mutant p53), and found that in consistency with its ability to block the activity of cyclin E/Cdk2 and cyclin B1/Cdc2 kinases, olomoucine caused cell cycle arrest at both G1/S and G2/S boundaries. Moreover, cell cycle arrest occurred equally well in these two cell lines bearing different p53 gene status, suggesting that p53 was not responsible for the cell cycle arrest by olomoucine. A similar p53-independent fashion was also observed in the cytotoxic potency and apoptosis induction of olomoucine, in contrast to ionizing radiation which caused more cytotoxic activity and apoptosis in the WMN cell line bearing wild-type p53 compared with CA46 cells bearing mutant p53. Such p53-independent cytotoxicity of olomoucine was also confirmed in other human Burkitt's lymphoma and lymphoid cell lines containing wild-type and mutant p53. Therefore, our results give an impetus to continued research into olomoucine that might be a very useful chemotherapeutic strategy in the treatment of patients with mutant p53 tumors, at least in lymphoma patients.

Apoptosis↗
PubMedDate not supplied

Cytokine stimulation of antibody-dependent cellular cytotoxicity (ADCC) enhances cytolytic but not binding capacity of peritoneal macrophages.

Macrophages in varying states of activation differ in their ability to perform antibody-dependent cellular cytotoxicity (ADCC). To define further the activation requirements for macrophages to perform cytolytic functions, we stimulated peptone-elicited peritoneal macrophages, which exhibit only a low level of ADCC, with a panel of cytokines and then assayed for the macrophages capacity to effect the rapid and slow forms of ADCC, to bind antibody-coated tumor cells, and to secrete H2O2 in response to immune complex or PMA. All four cytokine preparations, at optimal conditions, enhanced both forms of ADCC, but did not appreciably increase tumor cell binding. Three of the four cytokine preparations (Il-4, TNF and IFN-alpha/beta), however, increased the macrophages capacity to secrete H2O2 in response to either immune complex or PMA, IFN-gamma alone did not affect H2O2 secretion.

Animals↗