CSB Faculty
LuZhe Sun, Ph.D.
Professor
Rutgers University and UMDNJ-Robert Wood Johnson Medical School, 1990
(210) 567-5746
SUNL@UTHSCSA.EDU
Dr. Sun serves as Leader of Cell & Molecular Biology (CMB) Track of the Integrated Multidisciplinary Graduate Program (IMGP). He participated in the discovery of the tumor suppressive activity of the transforming growth factor beta type II receptor in human colon carcinomas. He lectures for the new Graduate School core course - Fundamentals of Biomedical Sciences and for the CMB Track core course - Advanced Cell and Molecular Biology. Dr. Sun has regularly been invited to serve on grant review panels for NIH and Department of Defense.
The primary research focus in my laboratory is on the molecular mechanisms of tumorigenesis and tumor progression of breast and prostate cancer, which are the most prevalent neoplasm in the US women and men respectively. We are particularly interested in how signaling pathways of growth factors and steroid hormones regulate cancer cell growth, invasion, and metastasis using molecular and cellular biology techniques and animal model systems. One of the molecules we are currently studying is called transforming growth factor beta (TGF-beta). This growth factor has been shown to promote cancer cell survival, invasion and metastasis in late-stage carcinoma cells. We are developing novel TGF-beta inhibitors that may have potential to be developed as novel drugs for cancer therapy. We are also investigating the molecular mechanisms that mediate the metastasis-promoting activity of TGF-beta, particularly the role of TGF-beta signaling in cancer-initiating cells and tumor stromal cells in the formation of a reactive tumor microenvironment during invasion and metastasis.
Systemic administration of a TGF beta type I receptor kinase inhibitor (TbRI-I) reduced breast cancer cell-induced metastatic tumor incidence and tumor burden in femora of nude mice.
Other projects in the laboratory include the role of estrogen and androgen signaling in promoting metastasis of breast and prostate cancer cells, respectively. Estrogen signaling is known to promote mammary tumorigenesis. However, our studies show that it also inhibits metastasis of breast cancer cells to bone and lung. We are investigating the molecular mechanism that mediate the tumor promoting activity of estrogen with respect to its role in cell proliferation and cellular senescence. We are also investigating whether estrogen receptor alpha and beta may act differently in controlling breast cancer metastasis. Our approaches to study the regulation of gene expression include transcriptional and posttranscriptional analyses with techniques such as gene microarray, promoter activity measurements, chromosome immunoprecipitation, polymerase chain reaction, quantitative real-time RT-PCR, receptor cross-linking, immunoprecipitation and Western blotting analyses. To study gene functions, we use sense transfection, RNA interference, and viral transduction techniques to regulate gene expression and then investigate the effects of altered gene expression on malignant phenotypes of cancer cells in tissue culture and in mice.
Research Techniques:
Immunoprecipitation and Western blotting
baculoviral and bacterial expression system
recombinant protein purification
receptor cross-linking
RT-PCR and real time PCR
promoter reporter assay
chromosome immunoprecipitation assay
cell culture
gene transfection
cell proliferation assays
immunohistochemistry
immunocytofluorescence staining
RNA interference
xenograft animal models of tumorigenesis, angiogenesis, and metastasis using nude mice, and
experimental models of lung and bone metastasis using nude mice
PUBLICATIONS:
Verona EV, Tang Y, Millstead TK, Hinck AP, Agyin JK, Sun LZ. (2008)
Expression, purification and characterization of BG(E)RII: a novel pan-TGFbeta inhibitor.
Protein Eng Des Sel. 2008 Jul;21(7):463-73. Epub 2008 May 21.
Verona EV, Elkahloun AG, Yang J, Bandyopadhyay A, Yeh IT, Sun LZ. (2007) Transforming growth factor-beta signaling in prostate stromal cells supports prostate carcinoma growth by up-regulating stromal genes related to tissue remodeling. Cancer Res. Jun 15;67(12):5737-46.
Bandyopadhyay A, Agyin JK, Wang L, Tang Y, Lei X, Story BM, Cornell JE, Pollock BH, Mundy GR, Sun LZ. (2006) Inhibition of pulmonary and skeletal metastasis by a transforming growth factor-beta type I receptor kinase inhibitor. Cancer Res. Jul 1;66(13):6714-21.
Bandyopadhyay A, Wang L, Lopez-Casillas F, Mendoza V, Yeh IT, Sun L. (2005) Systemic administration of a soluble betaglycan suppresses tumor growth, angiogenesis, and matrix metalloproteinase-9 expression in a human xenograft model of prostate cancer. Prostate. Apr 1;63(1):81-90.
Lei X, Zhu Y, Tomkinson A, Sun L. (2004) Measurement of DNA mismatch repair activity in live cells.. Nucleic Acids Res. Jul 12;32(12):e100.