Faculty Investigator

Mark R. Hellmich, Ph.D.

Associate Professor
Department of Surgery
email:mhellmic@utmb.edu

My major research interest is in the elucidation of signaling pathways regulated by heptahelical G-protein linked peptide hormone receptors of gastrointestinal (GI) tract, specifically those pathways coupled to the bombesin  and CCK/gastrin family of receptors.  Currently, my research activities are focused on:  1) defining the role of these peptide hormones and their receptors in regulating the interactions between epithelial and stromal cells during GI carcinogenesis, 2) define the mechanism by which mitogen activated protein kinases regulate peptide hormone-mediated release of intracellular Ca²⁺ from intracellular stores, and 3) characterizing the effects of intron 4 retention on the function of a novel splice-variant of the gastrin/CCK₂ receptor expressed in esophageal, pancreatic and colorectal cancers.

Selected Publications

Levine L, Lucci JA 3rd, Pazdrak B, Cheng JZ, Guo YS, Townsend CM Jr, Hellmich MR. Bombesin stimulates nuclear factor kappa B activation and expression of proangiogenic factors in prostate cancer cells. Cancer Res.63:3495-502, 2003.

Levine L, Licci JA 3rd, Townsend CM Jr, Hellmich MR. Expression of gastrin-releasing peptide receptors in endometrial cancer. J Am Coll Surg.19:898-904, 2003.

Olszewska-Pazdrak B, Townsend CM Jr, Hellmich MR.  Agonist-independent activation of Src tyrosine kinase by a cholecystokinin-2 (CCK2) receptor splice variant. J Biol Chem. 279:40400-4, 2004.

Olszewska-Pazdrak B, Ives KL, Park J, Townsend CM Jr, Hellmich MR. Epidermal growth factor potentiates cholecystokinin/gastrin receptor-mediated Ca2+ release by activation of mitogen-activated protein kinases. J Biol Chem. 279:1853-60, 2004.

Chao C, Ives KL, Goluszko E, Kolokoltsov AA, Davey RA, Townsend CM Jr, Hellmich MR. Src regulates constitutive internalization and rapid resensitization of a CCK₂ receptor splice variant. J Biol Chem, 280:33368-33373, 2005.

Chao C, Tallman ML, Ives KL, Townsend CM Jr, Hellmich MR.  Gastrointestinal hormone receptors in primary human colorectal carcinomas. J Surg Res, 129:313-321, 2005.

Chao C, Goluszko E, Lee Y-T, Kolokoltsov A A, Davey R A, Uchida T, Townsend Jr. C M, Hellmich MR.  Constitutively active CCK2 receptor splice variant increases Src-dependent HIF-1α expression and tumor growth. Oncogene, 26:1013-1019, 2007.

Hellmich MR and Evers BM.  Regulation of Gastrointestinal Normal Cell Growth. In: Physiology of the Gastrointestinal Tract 4^th Ed. 2006, pp 435-458, Leonard R. Johnson (ed). Elsevier Academic Press, Burlington, MA USA.

Chao C, Hellmich MR.  CCK₂ receptor splice variants in human gastrointestinal cancers, In Alternative Splicing in Cancer. 2006, pp 21-44, ISBN:81-7895-235-1, Julian P Venables (ed). Transworld Research Network, Kerala, India.