NURS 735 - APPLIED TOXICOLOGY

Cancer is a disease process that can affect all multicellular organisms, and remains a leading cause of death worldwide. Cancer should not be thought of as a single disease but rather a group of diseases which may have many characteristics in common but not necessarily the same causative agents, etiology or molecular profiles. In general, cancer defines diseases that have the capacity to invade surrounding normal tissue, metastasize (spread to distant sites) and kill the host in which it originates. Carcinogenesis is an important topic to include in this toxicology course since many of the causative "stress factors," or etiologies are associated with a variety of different environmental exposures. These exposures may occur through various routes of uptake, and may involve chemical compounds that serve as initiating or promoting agents (with or without bioactivation), irradiation and viruses.

To guide your understanding of key concepts throughout this module on carcinogenisis, the materials have been developed in eight sections. Each of these sections has respective learning objectives, listed below, and are linked by section title:

Section 1: Introduction to carcinogenesis
(Downloadable pdf file):

Know the definitions and basic terminology of Tumor, Dysplasia, Neoplasia, Differentiation, Anaplasia;
Describe the characteristics of/and differences between benign and malignant neoplasia based on biological behavior;
Understand the histogenetic classification of neoplasia;
Understand the basic growth characteristics of neoplasms; and
Understand the basic role of angiogenesis in neoplasia

Section 2: Characteristics of Benign and Malignant Neoplasia
(Narrated Flash presentation) (Downloadable pdf file):

Describe basic characteristics of neoplastic tissues and cells.
Describe differences between normal and neoplastic tissues and cells
Describe differences between benign and malignant neoplastic tissues and cells
Understand the basic mechanisms of metastasis

Section 3: Etiology and Pathogenesis of Neoplasia
(Narrated Flash presentation) (Downloadable pdf file):

Describe environmental factors which influence cancer risk
Understand the basic mechanistic hypotheses of carcinogenesis
Know the two major classes of chemical carcinogens based on mode of action and the mechanisms of chemical carcinogenesis
Define electrophile, nucleophile and ultimate carcinogen
Describe the basic paradigm for chemical carcinogenesis leading to initiated cells

Section 4: Radiation and Viruses
(Narrated Flash presentation) (Downloadable pdf file):

Understand that carcinogenesis (and other forms of cell injury) from ionizing radiation can develop (1) direct ionizing effects and (2) effects mediated by factors caused by the interaction of ionizing radiation and biological molecules in a cell.
Know that, in addition to chemicals, exposure to certain exposure and viruses are associated with carcinogenesis.

Section 5: Initiation and Promotion
(Narrated Flash presentation) (Downloadable pdf file):

Understand the concepts of initiation and promotion, and their role in carcinogenesis

Section 6: Molecular Basis of Cancer
(Narrated Flash presentation) (Downloadable pdf file):

Understand the concepts underlying the molecular basis of neoplasia development
Understand the multi-stage process of carcinogenesis
Know the basic groups of regulatory genes that are the principal targets of genetic damage leading to carcinogenesis
Understand the role of damaged or defective DNA repair genes in carcinogenesis

Section 7: Oncogenes and Tumor Supressor Genes
(Narrated Flash presentation) (Downloadable pdf file):

Understand the hypotheses related to the role of oncogenes in carcinogenesis
Know how protoncogenes can become oncogenes
Know the basic function of proteins encoded by oncogene sequences
Understand the mechanisms of oncogene activation
Describe the hypotheses for the role of activated oncogenes in carcinogenesis
Know the basic functions of tumor supressor genes
Describe the role of tumor suppressor genes in carcinogenesis
Be able to compare and contrast basic characteristics of oncogenes and tumor supressor genes
Understand the roles of oncogene activation and TSG inactivation in carcinogenesis

Section 8: Multi-stage Carcinogenesis
(Narrated Flash presentation) (Downloadable pdf file):

Describe various factors and mechanisms that modulate the carcinogenic process at discreet stages
Describe molecular events in the multi-step colon carcinogenesis model
Understand the relationships and interactions among factors involved in multi-stage carcinogenesis

Assignment:

Homework: Please develop a paragraph or two (less than a page) on the ethnic/racial/population differences in incidence for cancer of the uterine cervix in the U.S. and the factors mediating these differences. The following links will provide some information that may be useful for this discussion. Feel free to use additional resources and cite them.

http://seer.cancer.gov/publications/ethnicity/cervix.pdf

http://www.cancer.gov/templates/doc.aspx?viewid=1C763DE8-C2EF-4501-B440-09E836342FE9

http://prg.nci.nih.gov/gyno/default.html

http://prg.nci.nih.gov/gyno/finalreport.html#24