Gideon V. Wainwright

A Role for Sunlight in Skin Cancer: Research

Sunlight is a carcinogen that everyone is exposed to throughout life. This is considered to be a leading cause of skin cancer. Within the progression of tumor development, those that may be related to sunlight damage would be identified if they contained mutations specific to UV. It was found that 14/24 (58%) Of New England and Swedish patients found the mutation in the p53 tumor suppressor gene. The role of the UV light in the p53 mutations is shown by the double base change in three of the tumors which is known to be induced by UV. These mutations caused by the UV light are substitution mutations which can cause great harm because once it has mutated it replicates as the mutated gene. The squamous cell carcinoma of the skin is an ideal cancer for determining which of the many steps in tumorgenesis is carcinogen related.

The materials and methods used to research this were as such. Patients used for the tests were from the greater New York City or Uppsala, Sweden, areas. The tissue that was gathered for this testing were blocks of neutral-formalin-fixed squamous cell carcinogens for which the tumor originated in sun-exposed skin and as well the epidermis contained at the least 50% bordering invasive carcinoma. For a few of the patients more then one sample was taken of the tumor and all samples were coded anonymously. The Dana-Farber Cancer Institute, Boston supplied the squamous cell carcinoma line 13. Sections were removed and the DNA Amplification took place, in some cases the normal tissue flanking the carcinoma was as well amplified. Each set did contain the negative controls of reaction. The reactions of every amplification were analyzed. To determine the results to be true the DNA must be tested several times to be accurate. In order to test the samples many times the DNA is replicated and this is called PCR Sequencing.

The results from all the data gathered from the materials and methods procedure. Paraffin sections of invasive squamous cell carcinomas from sun-exposed skin were surveyed by direct DNA sequencing of PCR amplification products of the p53 gene. For each of the mutations a-d the exact test was used to compare the proportion of such mutations in the internal malignancies versus the proportion in either the squamous cell carcinoma or the UV studies. In contrast the distribution of mutation among types a-d is very similar between the squamous cell carcinoma of the skin and UV mutagenesis studied in market genes.

The end results bring about all sorts of discussions. Mutated, deleted, rearranged,