Home > Faculty > Dr. Xiang-Xi (Mike) Xu



Xiang-Xi (Mike) Xu, Ph.D.

Professor Sylvester Comprehensive Cancer Center
Molecular, Cell and Developmental Biology Graduate Program


Research Interests

Our laboratory research explores the molecular mechanisms of epithelial differentiation and morphogenesis during embryogenesis and the alterations that lead to epithelial cell transformation in carcinogenesis. One hallmark of carcinomas, malignancies of epithelial origin, is the loss of cell positional organization: cancer cells are no longer arranged as a discrete epithelium. Thus, genes and mechanisms governing epithelial cell organization are obviously necessary targets of carcinogenic alterations. Often these genes and mechanisms are also involved in epithelial morphogenesis during embryonic development. The laboratory concentrates on two epithelial biological systems: the transformation of the ovarian surface epithelium to cancer, and the genesis of the primitive endoderm, an epithelial structure in early embryos. We have recognized a striking conservation in the molecular mechanisms and genes between epithelial morphogenesis and neoplastic transformation, and are studied in parallel both development and cancer. We hope that the studies will reveal critical mechanisms in ovarian carcinogenesis and also contribute to the fundamental understanding of cell differentiation and morphogenesis in early embryonic development. Specifically, our main research projects include the following:

Mechanisms in cell differentiation and pattern formation in primitive endoderm development and early embryogenesis.

The role of Dab2 gene in epithelial polarity and in morphological transformation of carcinoma cells.

The role of GATA transcription factors in epithelial dedifferentiation of ovarian cancer cells.

Development and study of an ovarian tumor mouse model reflecting postmenopausal ovarian cancer risk.

Role of nuclear envelope defects in chromosomal instability and cancer



Selected Publications

Cai KQ, Capo-chichi CD, Rula EM, Yang DH, Xu XX. Dynamic GATA6 expression in primitive endoderm formation and maturation in early mouse embryogenesis.  Developmental Dynamics.  2008, in press.
Smith ER, Xu XX.  Ovarian aging, follicle depletion, and cancer: A hypothesis for the etiology of epithelial ovarian cancer involving follicle depletion.  Lancet Oncology. 2008, in press.

McEachin MD, Xu XX, Santoianni RA, Lawson D, Cotsonis G, Cohen C. GATA-4 and GATA-6 expression in human ovarian surface epithelial carcinoma. Appl Immunohistochem Mol Morphol. 2008 Mar;16(2):153-8.

Rula ME, Cai KQ, Moore R, Yang DH, Staub CM, Capo-Chichi CD, Jablonski SA, Howe PH, Smith ER, Xu XX. Cell autonomous sorting and surface positioning in the formation of primitive endoderm in embryoid bodies. Genesis. 2007 Jun;45(6):327-38.

Yang DH, Cai KQ, Roland IH, Smith ER, Xu XX. Disabled-2 is an epithelial surface positioning gene. J Biol Chem. 2007 Apr 27;282(17):13114-22.

Cai KQ, Yang WL, Capo-Chichi CD, Vanderveer L, Wu H, Godwin AK, Xu XX. Prominent expression of metalloproteinases in early stages of ovarian tumorigenesis. Mol Carcinog. 2007 Feb;46(2):130-43.

Yang DH, Fazili Z, Smith ER, Cai KQ, Klein-Szanto A, Cohen C, Horowitz IR, Xu XX. Disabled-2 heterozygous mice are predisposed to endometrial and ovarian tumorigenesis and exhibit sex-biased embryonic lethality in a p53-null background. Am J Pathol. 2006 Jul;169(1):258-67.

Caslini C, Capo-chichi CD, Roland IH, Nicolas E, Yeung AT, Xu XX. Histone modifications silence the GATA transcription factor genes in ovarian cancer. Oncogene. 2006 Aug 31;25(39):5446-61.

Capo-Chichi CD, Rula ME, Smedberg JL, Vanderveer L, Parmacek MS, Morrisey EE, Godwin AK, Xu XX. Perception of differentiation cues by GATA factors in primitive endoderm lineage determination of mouse embryonic stem cells. Dev Biol. 2005 Oct 15;286(2):574-86.

Smith ER, Smedberg JL, Rula ME, Xu XX. Regulation of Ras-MAPK pathway mitogenic activity by restricting nuclear entry of activated MAPK in endoderm differentiation of embryonic carcinoma and stem cells. J Cell Biol. 2004 Mar 1;164(5):689-99.



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