David W . Oleksyn

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To examine whether a BMP signaling pathway functions in specification of cell fates in sea urchin embryos, we have cloned sea urchin BMP2/4, analyzed its expression in time and space in developing embryos and assayed the developmental consequences of changing its concentration through mRNA injection experiments. These studies show that BMP4 mRNAs accumulate(More)
We have identified a single homolog of goosecoid, SpGsc, that regulates cell fates along both the animal-vegetal and oral-aboral axes of sea urchin embryos. SpGsc mRNA is expressed briefly in presumptive mesenchyme cells of the approximately 200-cell blastula and, beginning at about the same time, accumulates in the presumptive oral ectoderm through pluteus(More)
We have identified a Sox family transcription factor, SpSoxB1, that is asymmetrically distributed among blastomeres of the sea urchin embryo during cleavage, beginning at 4th cleavage. SpSoxB1 interacts with a cis element that is essential for transcription of SpAN, a gene that is activated cell autonomously and expressed asymmetrically along the(More)
Localization of nuclear beta-catenin initiates specification of vegetal fates in sea urchin embryos. We have identified SpKrl, a gene that is activated upon nuclear entry of beta-catenin. SpKrl is upregulated when nuclear beta-catenin activity is increased with LiCl and downregulated in embryos injected with molecules that inhibit beta-catenin nuclear(More)
The animal-vegetal (A-V) axis of the sea urchin embryo is established before fertilization. Classical experiments showed that animal and vegetal halves of bisected eggs have different developmental potentials, since only vegetal halves inherit the maternally derived program required for mesendoderm tissues while animal halves form poorly differentiated(More)
Diffuse large B-cell lymphoma (DLBCL) is an aggressive and the most common type of non-Hodgkin lymphoma. Despite recent advances in treatment, less than 50% of the patients are cured with current multiagent chemotherapy. Abnormal NF-kappaB activity not only contributes to tumor development but also renders cancer cells resistant to chemotherapeutic agents.(More)
Diffuse large B-cell lymphoma (DLBCL), the most common type of non-Hodgkin lymphoma, remains a partially curable disease. Genetic alterations affecting components of NFB signaling pathways occur frequently in DLBCL. Almost all activated B cell–like (ABC) DLBCL, which is the least curable group among the 3 major subtypes of this malignancy, and a substantial(More)
Activation of the transcription factor NF-κB induced by extracellular stimuli requires IKKα and IKKβ kinase activity. How IKKα and IKKβ are activated by various upstream signaling molecules is not fully understood. We previously showed that protein kinase C-associated kinase (PKK, also known as DIK/RIP4), which belongs to the receptor-interacting protein(More)
Non-melanoma skin cancer represents the most common cancer in the United States. Squamous cell carcinoma (SCC) of the skin is a subtype of NMSC that shows a greater potential for invasion and metastasis. The current study identifies the protein kinase C-associated kinase (PKK), which is also known as the receptor-interacting protein kinase 4, as a(More)
Previous studies in sea urchin embryos have demonstrated that nuclearization of beta-catenin is essential for initial steps in the specification of endoderm and mesenchyme, which are derived from vegetal blastomeres. This process begins at the 4th and extends through the 9th cleavage stage, an interval in which the SpSoxB1 transcription regulator is(More)