title: Mechanisms of resistance to ionizing radiation in rectal cancer.
abstract: While patients with breast cancers are not subjected to the adverse side effects of tamoxifen or trastuzumab if their tumors are negative for estrogen, progesterone or Her-2/Neu, neoadjuvant ionizing radiation with concurrent chemotherapeutic agents is administered almost universally to patients with stage II/III rectal cancers. There is, however, a tremendously wide range of response to this preoperative modality from complete pathological response to continuous tumor growth in patients receiving the same form of treatment. The specific phenotype of the tumor plays a major role in rendering tumor cells survival advantage to the cytotoxic effects of chemoradiation. Pathways such as proliferation, cell cycle, apoptosis and hypoxia have been investigated under a variety of conditions in preirradiated tissues and postirradiated tumors. This article reviews the current evidence available to identify a molecular profile predictive of the best response to ionizing radiation.
authors: Department of Surgery, University of Texas Southwestern Medical Center/Dallas VA Medical Center, 4500 Lancaster Road, Dallas, TX 75216, USA. sergio.huerta@utsouthwestern.edu
authors: Sergio
authors: S
authors: Huerta
authors: Xiaohuan
authors: X
authors: Gao
authors: Debabrata
authors: D
authors: Saha
mesh_terms: D017209:Apoptosis; D001706:Biopsy; D002453:Cell Cycle; D016923:Cell Death; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D006801:Humans; D008495:Medical Oncology / Q000379:methods; D008954:Models, Biological; D025202:Molecular Diagnostic Techniques; D009389:Neovascularization, Pathologic; D020411:Oligonucleotide Array Sequence Analysis; D011839:Radiation, Ionizing; D012004:Rectal Neoplasms / Q000235:genetics* / Q000473:pathology / Q000532:radiotherapy*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53