Identification of Novel Human Cancer-Specific Antigens - Literature review Example

Epithelial cells contact and metabolize ingested carcinogens. As a result, about 90 percent of cancers are essentially epithelial (Alison, 2001). Cancer is known to be ubiquitous, takes many forms, and is deadly causing about 17% of annual deaths worldwide. In terms of behavior, tumors can be classified as either benign type or malignant type (Alison, 2001). Prostate cancer, lung cancer, esophageal cancer, and colon cancer are most prevalent in men (Quinn, 2013), while the most prevalent in the female population are breast cancer, lung cancer, cervical cancer, and colon cancer.

The most fundamental cancer cell traits involve their power to maintain chronic proliferation and multiplication (Robert A Weinberg, 2011). On a cellular level, it is seen that cancer is quite rare due to the fact that it is a result of accumulated mutations and mutated clones (figure1). Single cells normally have the ability to eliminate these aberrations by genetic repair or apoptosis. These two will be touched on in brief in the coming paragraph. Signaling of the cancer cells plays an important role, as cancerous cells, as well as normal cells, rely greatly on extracellular messages to survive and grow. Cancer cells may synthesize and secrete growth factor ligands by themselves. They respond to this by expressing cognate receptors on their surfaces (Robert A Weinberg, 2011). The production of growth factors results in proliferation fostered by an autocrine mechanism. An alternate method utilized by the neoplastic cells would be to send signals to stimulate normal cells within the supportive matrix. This is otherwise known as the tumor-associated stroma (TAA). These are normally healthy cells that end up producing the required growth factors in a reciprocating fashion (Douglas Hanahan, 2011).  When studying the patterns and mechanisms of cell signaling, it is seen that cancers can also utilize paracrine and endocrine signaling methods, and not only the autocrine (Allison, 2001).

There are six main hallmark capabilities of a cancerous cell. They include; resisting cell death/ apoptosis, evading growth suppressors, sustaining proliferative signaling, activating metastases and invasion, enabling replicative immortality, and inducing angiogenesis. (Douglas Hanahan, 2011)

Legend; pink-first generation neoplastic cells, blue-second generation neoplastic cells, green-third generation NCs, Purple- fourth-generation NCs and black-necrotic cells

Apoptosis is basically a suicidal response of cells to irreparable genetic errors and is a major component of cancer development. The main gene involved in the p53 leads to transcription of a mitochondrial protein, Bax. It is a part of a family of three proteins that are the judges of apoptosis, located on the outer mitochondrial membrane. When the DNA is destroyed, or the cell injured as in irradiation by gamma rays, signals go to both the apoptotic pathways and repair pathways.  The repair pathway mainly aims at reconstructing the DNA and thus restoring it to its proper functionality. DNA damage may be a double strand or single strand. Several mechanisms of DNA repair are dependent on the type of damage.