Oral Squamous Cell Carcinoma From Users and Nonusers of Tobacco and Alcohol: Clinicopathologic Features and Immunoreactivity of VEGF, Caspase-3, and P53

Decoding the influence of the immune system and immunotherapy targets on carcinomas: A hidden prism in oral cancer therapy

In recent decades, understanding tumorigenesis and the complex interaction between the host and the immune system has been the pillar for significant advances in anticancer therapy. Conventional anticancer therapy (e.g., cut, burn, and cytotoxic drugs) involves multiple targeting of tumor cells. However, the tumor tissue microenvironment can present a dysregulated, stimulating, or subverted immune response which, in turn, reveals pro-tumor activities favoring tumor expansion and progression. Recently, new potential targets have been identified based on immunomodulatory therapies, which are crafted to re-establish the host anti-tumoral immune response. Clinicians should fully understand the intricate interactions between carcinogens, the tumor milieu, the immune system, and traditional anticancer therapies in order to progress and to overcome the refractory/recurrent challenges and morbidity of the disease. Thus, in this article, we highlight the complex milieu of the oral cancer immune response, pointing out potential therapeutic immunotargets for oral squamous cell carcinomas. The impact of traditional anticancer therapy on the immune system is also outlined.

Proteomic Alterations Associated with Oral Cancer Patients with Tobacco Using Habits

Tobacco abuse is a major risk factor associated with the development of oral squamous cell carcinoma. Differences in molecular aberrations induced by tobacco exposure by chewing or smoking form are not well studied in case of oral cancer. We used tandem mass tag-based quantitative proteomic approach to delineate proteomic alterations in oral cancer patients based on their history of tobacco using habits (patients who chewed tobacco, patients who smoked tobacco, and those with no history of tobacco consumption). Our data identified distinct dysregulation of biological processes and pathways in each patient cohort. Bioinformatics analysis of dysregulated proteins identified in our proteomic study revealed dysregulation of collagen formation and antigen processing/presentation pathway in oral cancer patients who smoked tobacco, whereas proteins associated with the process of keratinization showed enrichment in patients who chewed tobacco. In addition, we identified overexpression of proteins involved in immune pathways and downregulation of muscle contraction-mediated signaling events in all three cohorts, irrespective of tobacco using habits. This study lays the groundwork for identification of protein markers that may aid in identification of high-risk patients for cancer development based on the history of tobacco exposure habits.

Assessment of Histopathological Grade and Ki-67 Expression in Tobacco and Non-tobacco Habitual Buccal Mucosa Cancer

Although there are various risk factors in the literature, the established primary risk factor for oral cancer is tobacco and betal-nut chewing habits. It is believed that pathogenesis of oral cancer depends on the aetiology. To assess the histopathological grade and Ki-67 expression in tobacco (smoking/smokeless) and non-tobacco (betal nut/pan masala) habitual buccal mucosa cancer. The cross-sectional study was carried out in Regional cancer centre, Tamilnadu. Proliferative marker, Ki-67 expression was determined by immunohistochemistry using biotin-streptavidin method. The study includes 117 buccal mucosa cancer patients (61 male and 56 female). According to WHO grading system, high frequency observed with well differentiated squamous cell carcinoma 48 (41%) followed by moderate 46 (39.3%) and poorly differentiated 23 (19.7%). The cut-off value 50% was used to categorize Ki-67 expression into low and high labelling index (LI); 96 (82%) buccal mucosa cancer and 4 (3.4%) adjacent normal mucosa patients showed high Ki-67 expression. The present study showed highly significant association of histopathological tumor grade and Ki-67 expression by Chi square and paired t test p < 0.05. All the patients were grouped as tobacco 87 (74.4%) and non-tobacco habitual 30 (25.6%) in 3:1, respectively. Further, the risk habits identified with significant differences of tumor grade (p = 0.028) and Ki-67 at p < 0.05. Thus, the study revealed that the nature of cell differentiation and proliferation was strongly related to consumption of carcinogen in both tobacco and non-tobacco form. Therefore, histopathological grade and Ki-67 could be used as a reliable biomarker to understand the biological behaviour of risk habits which might helpful for further treatment therapeutics.

Smoking-induced changes in cancer-related factors in patients with upper tract urothelial cancer

Cigarette smoking is a major risk factor for urothelial cancer (UC) development. However, the associations between smoking and changes in the pathological characteristics and molecular expression of cancer-related molecules in upper tract (UT) UC have not been fully elucidated. We investigated the associations between smoking status and cancer-related factors, including cancer cell proliferation, apoptosis, angiogenesis, lymphangiogenesis and expression of vascular endothelial growth factor-A and -C, matrix metalloproteinase (MMP)-2 and -9, cyclooxygenase (COX)-2 and urokinase-type plasminogen activator, in patients with UTUC. A total of 134 patients who underwent nephroureterectomy were retrospectively investigated. Proliferation index (PI), microvessel density and lymphatic vessel density (LVD) were measured using anti-Ki-67, anti-CD105 and anti-D2-40 antibodies in formalin-fixed specimens. The apoptotic index was evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. Other cancer-related molecules were investigated by immunohistochemistry in similar specimens. The patients were divided into three groups; non-smoker (n=54, 40.3%), former smoker (n=46, 34.3%) and current smoker (n=34, 25.4%). The PI and the apoptotic index were not found to be correlated with smoking status; however, the mean/standard deviation level of LVD in current smokers (40.9/12.9) was significantly higher (P=0.034) compared to that in patients who had never smoked (34.4/10.6). In addition, smoking status was positively correlated with the presence of intratumoral lymphatic vessels (iLV) (P=0.010) and the expression of COX-2 and MMP-9 (P=0.032). The multivariate analysis demonstrated that current smoking was independently associated with all the abovementioned smoking-related factors. However, former smoking was correlated with LVD and the presence of iLV. In the survival analysis, LVD, the presence of iLV and the expression of COX-2 and MMP-9 were identified as predictive factors for metastasis following surgery. In conclusion, lymphangiogenesis and the expression levels of COX-2 and MMP-9 were found to be associated with the smoking status of UTUC patients. Our results may provide important insights into the pathological changes precipitated by smoking in these patients.