الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 174 |  |  |
| | | from | 174 | | |
Abstract
Oral squamous cell carcinoma is a multifactorial disease. It is influenced by genetic modifications; as well as numerous environmental factors, such as smoking, tobacco chewing, alcohol consumption, infection by oncogenic viruses, and low intake of fruits and vegetables.
During the last decade, a clear evidence has been obtained that inflammation plays a critical role in tumorigenesis. Cytokines are important components of inflammation. They are cell-signaling protein molecules which affect the intercellular communication. They are observed to be produced in the tumor microenvironment, indicating their suggestive role in cancer pathogenesis.
Interleukin-10 is a potent pleiotropic cytokine with immunosuppressive and anti-inflammatory functions, as well as anti-cancer activities. Various cell populations are able to produce it. However, the major source of IL-10 production is macrophages. Increased IL-10 expression in tumor tissues, serum and saliva was noted in different cancer types. In addition, this raised concentration was proposed as an indicator of poor prognosis.
The aim of the current study was to evaluate and correlate the expression of IL-10 in different histopathological grades of OSCC, as well as to assess its serum and salivary levels.
In the present study, a total of twenty patients with OSCC were included. Their age ranged between 35 and 76 years. Thirteen patients (65%) were males and seven patients (35%) were females.
The most common site of occurrence of OSCC was the lateral side of the tongue (35%), followed by the buccal mucosa (25%), then floor of the mouth (15%). Finally, both the alveolar mucosa and the maxillary tuberosity were equal (10% for each), and the lower lip was the least occurring site (5%).
The clinical staging of the patients was as follows; stage II was the predominant (40%), followed by stage I (35%), then stage IVA (20%), and the least common stage was stage III (5%).
Biopsies were histologically evaluated using Haematoxylin and Eosin (H&E) staining. The microscopical examination revealed that 35% of the cases were well differentiated, 55% were moderately differentiated and 10% were poorly differentiated.
Serial sections were immunohistochemically stained by monoclonal antibody to IL-10 using Labeled- Strept -Avidin Biotin (LSAB) complex method. The intensity of immunostaining of IL-10 was calculated in terms of mean area percent and mean optical density by the computer image analyzer.
All cases of normal oral mucosa (n=5) showed negative immunoreactivity for IL-10, while OSCC biopsies (n=20) were immunostained. Cytoplasmic IL-10 immunosignaling was detected in the well and moderately differentiated grades of OSCC, while both cytoplasmic and nuclear immunoreactions were observed in the poorly differentiate type.
The IHC staining intensity was found to be directly proportional to the histopathological grading of OSCC, where the poorly differentiated type has the highest staining intensity, followed by the moderately and the well differentiated grades respectively.
The difference in the mean IL-10 area percent and mean optical density between the well, moderately and poorly differentiated groups revealed statistical significance at (P≤0.05). On the other hand, it was insignificant between OSCC stages (P˃0.05).
The Enzyme-Linked Immunosorbent Assay (ELISA) method was used to determine the concentration of IL-10 in the serum and saliva of normal individuals and OSCC patients. IL-10 levels in serum and saliva showed no significant difference between the study group and the control group (P > 0.05).
Finally, statistical analysis by F- test (ANOVA) revealed that both mean area percent and mean optical density of IL-10 were significantly correlated with its serum and salivary levels in OSCC patients (P≤0.05).
The current study concluded that IL-10 can be detected immunohistochemically in human tissues of OSCC. The marker expression is directly proportional to the histopathological grading of the disease. The levels of IL-10 in tissue, serum and saliva are correlated to each other in OSCC patients. This could reflect the same way of regulation of this cytokine in different parts of the body.