Approximately 44,000 women die of breast cancer in the United States each year, and after lung cancer, breast cancer is the most common cause of cancer death in women. Several aspects of breast cancer onset and disease progression have been linked to members of the TGF2 superfamily and their associated downstream signaling components, the Smads. The long-term goal of our work is to investigate how alterations in Smad 3 signal transduction affect breast cancer progression to help establish a molecular staging of disease and to facilitate the discovery of novel treatment strategies that will result in disease regression. The hypothesis of this proposal is that in cyclin overexpressing breast cancers, activation of CDK4/2 leads to phosphorylation and inhibition of Smad 3, thus releasing cell cycle arrest and promoting cell proliferation and metastasis. Our hypothesis is based on the following observations: 1) Smad 3 signaling contributes to G1 cell cycle arrest through transcription of cyclin dependent kinase (CDK) inhibitors and repression of the cell cycle mitogen c-myc, 2) Smad 3 action is inhibited upon phosphorylation by CDK4/2, kinases that are regulated by cyclins D and E, 3) Certain aggressive, basal-type breast cancers overexpress cyclins and have poor outcomes associated with highly metastatic disease. Predicated on these findings, the three specific aims of this proposal will directly examine the interaction between cyclin overexpression and Smad 3 inhibition in breast cancer as follows:
Aim 1 : Investigate cyclin-mediated mechanisms of Smad 3 inhibition and the impact of this inhibition on G1 arrest.
This aim will test the effects of CDK phosphorylation on Smad 3-mediated cell cycle control and utilize a transcription factor reporter array to assess the downstream consequences of cyclin overexpression in breast cancer cells.
Aim 2 : Investigate the effect of CDK inhibition on the proliferation of cyclin overexpressing breast cancer cells in vitro and in primary and metastatic xenografts using murine models.
This aim will test the hypothesis that CDK4/2 inhibition of Smad 3 phosphorylation decreases breast cancer cell proliferation in in vitro cultures and in vivo murine models.
Aim 3 : Investigate the expression patterns of Smad 3, cyclin D, cyclin E, CDK4 and CDK2 in grades 1, 2, and 3 human breast cancer tissues, basal-like breast cancers, and normal mammary tissue.
This aim will test whether subtypes of breast cancer exist with patterned expression of Smad 3, cyclins and CDKs, which correlate with more established breast cancer prognostic markers.
The study of new tumor suppressors such as Smad 3 may expand the conventional staging and grading of breast cancer by facilitating an organized molecular staging of disease. These efforts will ultimately allow for the further development of individualized prognostic markers to actualize patient-specific treatment strategies. Therapeutic targeting of CDK/cyclin activity to restore Smad 3 tumor suppression may hold promise for patients with cyclin overexpressing and basal-like breast cancers, who currently have the disease sub-type with the worst prognosis.
|Kaklamani, Virginia G; Jeruss, Jacqueline S; Hughes, Elisha et al. (2015) Phase II neoadjuvant clinical trial of carboplatin and eribulin in women with triple negative early-stage breast cancer (NCT01372579). Breast Cancer Res Treat 151:629-38|
|Tarasewicz, Elizabeth; Hamdan, Randala; Straehla, Joelle et al. (2014) CDK4 inhibition and doxorubicin mediate breast cancer cell apoptosis through Smad3 and survivin. Cancer Biol Ther 15:1301-11|
|Tarasewicz, Elizabeth; Rivas, Lisbi; Hamdan, Randala et al. (2014) Inhibition of CDK-mediated phosphorylation of Smad3 results in decreased oncogenesis in triple negative breast cancer cells. Cell Cycle 13:3191-201|
|Gracia, Clarisa R; Jeruss, Jacqueline S (2013) Lives in the balance: women with cancer and the right to fertility care. J Clin Oncol 31:668-9|
|Tarasewicz, Elizabeth; Jeruss, Jacqueline S (2012) Phospho-specific Smad3 signaling: impact on breast oncogenesis. Cell Cycle 11:2443-51|
|Boukaidi, Samir Alexandre; Cooley, Anne; Hardy, Ashley et al. (2012) Impact of infertility regimens on breast cancer cells: follicle-stimulating hormone and luteinizing hormone lack a direct effect on breast cell proliferation in vitro. Fertil Steril 97:440-4|
|Cooley, Anne; Matthews, Laura; Zelivianski, Stanislav et al. (2012) Effect of infertility treatment and pregnancy-related hormones on breast cell proliferation in vitro. Hum Reprod 27:146-52|
|Jeruss, Jacqueline S; Kuerer, Henry M; Beitsch, Peter D et al. (2011) Update on DCIS outcomes from the American Society of Breast Surgeons accelerated partial breast irradiation registry trial. Ann Surg Oncol 18:65-71|
|Bellis, Abigail D; Penalver-Bernabe, Beatriz; Weiss, Michael S et al. (2011) Cellular arrays for large-scale analysis of transcription factor activity. Biotechnol Bioeng 108:395-403|
|Cooley, Anne; Zelivianski, Stanislav; Jeruss, Jacqueline S (2010) Impact of cyclin E overexpression on Smad3 activity in breast cancer cell lines. Cell Cycle 9:4900-7|
Showing the most recent 10 out of 12 publications