Comparison of features of human breast cancer cell lines and their corresponding tumors.

Although human tumor-derived cell lines play an important role in the investigation of cancer biology and genetics, there is no comprehensive study comparing tumor cell line properties with those of the individual tumors from which they were derived. We compared the properties of a series of 18 human breast cancer cell lines that were cultured for a median period of 25 months (range, 9-60 months) and their corresponding archival tumor tissues. We compared morphological characteristics, ploidy, and immunohistochemical expression of estrogen receptors, progesterone receptors, and HER2/neu and p53 proteins.

A gamete-specific, sex-limited homeodomain protein in Chlamydomonas.

During fertilization in Chlamydomonas, gametes of opposite mating types interact with each other through sex-specific adhesion molecules on their flagellar surfaces. Flagellar adhesion brings the cell bodies of the gametes into close contact and initiates a signal transduction pathway in preparation for cell-cell fusion. We have identified a cDNA, gsp1, whose transcript levels are upregulated during flagellar adhesion.

Characterization of paired tumor and non-tumor cell lines established from patients with breast cancer.

The goal of our study was to develop a panel of tumor cell lines along with paired non-malignant cell lines or strains collected from breast cancers, predominantly primary tumors. From a total of 189 breast tumor samples consisting of 177 primary tumors and 12 metastatic tissues, we established 21 human breast tumor cell lines that included 18 cell lines derived from primary tumors and 3 derived from metastatic lesions. Cell lines included those from patients with germline BRCA1 and FHIT gene mutations and others with possible genetic predisposition.

Cell wall biogenesis in Chlamydomonas: molecular characterization of a novel protein whose expression is up-regulated during matrix formation.

In the unicellular eukaryote Chlamydomonas, disruption of cell-matrix interactions by treatment with a periplasmic matrix metalloproteinase, g-lysin, activates a signal transduction pathway that results in the rapid synthesis and secretion of matrix molecules, followed by their assembly into a new matrix. I have identified and partially characterized several cDNA clones for transcripts that are dramatically up-regulated following treatment of cells with g-lysin. Here I report the complete nucleotide sequence and preliminary characterization of a matrix-related molecule termed Mrp47.

SksC, a fertilization-related protein kinase in Chlamydomonas, is expressed throughout the cell cycle and gametogenesis, and a phosphorylated form is present in both flagella and cell bodies.

Fertilization in the biflagellated eukaryote, Chlamydomonas, is initiated by flagellar adhesion between gametes of opposite mating types. An early event in the signal transduction pathway induced by these cell-cell interactions is the rapid inactivation of a flagellar protein kinase that phosphorylates a 48 kDa flagellar protein. Molecular cloning and characterization indicated that the 48 kDa substrate, termed SksC, itself is a novel protein kinase.

Molecular cloning of a protein kinase whose phosphorylation is regulated by genetic adhesion during Chlamydomonas fertilization.

Fertilization in Chlamydomonas is initiated by adhesive interactions between gametes of opposite mating types through flagellar glycoproteins called agglutinins. Interactions between these cell adhesion molecules signal for the activation of adenylyl cyclase through an interplay of protein kinases and ultimately result in formation of a diploid zygote. One of the early events during adhesion-induced signal transduction is the rapid inactivation of a flagellar protein kinase that phosphorylates a 48-kDa protein in the flagella.

Increased transcript levels of a methionine synthase during adhesion-induced activation of Chlamydomonas reinhardtii gametes.

Chlamydomonas gametes of opposite mating types interact through flagellar adhesion molecules called agglutinins leading to a signal transduction cascade that induces cell wall loss and activation of mating structures along with other cellular responses that ultimately result in zygote formation. To identify molecules involved in these complex cellular events, we have employed subtractive and differential hybridization with cDNA from mt+ gametes activated for fertilization and non-signaling, vegetative (non-gametic) cells. We identified 55 cDNA clones whose transcripts were regulated in activated gametes.