Oral cancer tissue studies

There is a considerable literature on the differentiation of cancer and noncancer so we have limited our description to examples of work in this area. Tobin et al. (2004) used synchrotron IR to differentiate oral cancer tissue, using air dried tissue sections, from the surrounding normal tissue using PCA and LDA. Sections were subsequently stained and good correlation was achieved indeed, in one section where visually the tissue appeared to be non-cancer but for which the speetra fitted the cancer profile, after staining it became clear that there were cancer cells in the area from which the speetra had been obtained. The possibility of obtaining IR spectra from cells which have already been stained opens up a new avenue in the study of pathology samples with Fourier Transform Infra-Red (FTIR) spectroscopy. ... 

Livny, O., Kaplan, I., Reifen, R., Polak-Charcon, S., Madar, Z., and Schwartz, B. 2003. Oral cancer cells differ from normal oral epithelial cells in tissue like organization and in response to lycopene treatment An organotypic cell culture study. Nutr. Cancer 47, 195-209. 

Chronic-Duration Exposure and Cancer. Limited studies are available on the effects in humans chronically exposed to chlorobenzene via inhalation and suggest that nervous system is a target tissue. Specific exposure data were not provided. No information is available on effects of chlorobenzene in humans following chronic oral or dermal exposure. Inhalation and oral studies in animals identified the same target tissues as for intermediate-duration exposure. One study in rats demonstrated that the immune system can also be adversely affected via oral exposure. Inhalation studies in humans and inhalation and oral studies in animals are sufficient to identify main target tissues. A chronic MRL was not derived since human exposure data were lacking and the one animal study did not evaluate a sufficient number of end points and test animals. Further studies via the dermal route would provide additional toxicity data for an assessment of potential risk to humans. 

Rogers MA, Thomas DB, Davis S, et al. 1991. A case control study of oral cancer and pre-diagnostic concentrations of selenium and zinc in nail tissue. Int J Cancer 48(2) 182-188. 

A clinical trial to evaluate misoprostol as a protector of normal tissue during a course of XRT in cancer patients suggests a reduction in acute normal tissue injury (215). A randomized, prospective, double-blind study indicates that topical misoprostol, administered as an oral rinse 15-20 min before irradiation using conventional 2-Gy (200 rad) fractions, five days a week over 6—7 weeks, significantly protects the oral mucosa from radiomucositis, a frequently observed normal tissue complication during XRT for head and neck cancer (215). 

In one study by Hood et al., 282 of 1153 identified proteins were identified by at least 2 unique tryptic peptides from FFPE prostate cancer (PCa) tissue.9 According to the gene ontology classification of the proteins identified, -65% of proteins were predicted to be intracellular proteins, while -50% of the total human proteome is predicted to be located in the intracellular compartment. Additionally, 20% of the proteins identified in the PCa tissue were classified as membrane proteins, which is significantly less than the predicted 40% for the human proteome. This relative disparity is not unexpected, considering the Liquid Tissue sample preparation kit lacks specific protocols for membrane protein extraction. The Liquid Tissue method has also been used for proteomics studies of a variety of FFPE tissue samples, including pancreatic tumors,28 squamous cell carcinoma,4 and oral human papillomavirus lesions.27... 

Further studies have validated this hypothesis, in part,4 and ultimately this inventive premise was borne out in clinical practice. As a result, 5-FU (5) was eventually approved for treatment of solid tumors, such as breast, colorectal, and gastric cancers. Marketed as Adrucil when administered intravenously, 5-FU can be used either as monotherapy or combination therapy with various cytotoxic drugs and biochemical modulators, such as leucovorin and methotrexate.5 Because 5-fluorouracil is not orally bioavailable, it must be administered by continuous infusion to optimize its efficacy due to its short half-life in plasma. In addition, 5-FU has poor selectivity toward tumors in vivo, and its distribution into tissues such as bone marrow, the gastrointestinal tract, the liver and skin causes high incidences of toxicity. In addition, in spite of its limited lipid solubility, 5-fluorouracil diffuses readily across the blood-brain barrier into cerebrospinal fluid and brain tissue.1,5... 

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