In vivo and in vitro observation of cellular immune parameters in squamous cell carcinoma of the oral cavity and its correlation with tumor load and prognosis

Evaluation of differential white blood cell count and cheek pouch epithelium in 7,12-dimethylbenza[a]anthracene hamster carcinogenesis model, managed with three phytochemicals

Objectives: Nigella sativa (NS), thymoquinone (TQ), and epigallocatechin-3-gallate (EGCG) are phytochemicals that might have antioxidant protective potentials on the hamster cheek pouch epithelium (HCPE). We aimed at evaluating and comparing the potential therapeutic outcomes of these 3 phytochemicals by analysis of peripheral white blood cells (WBCs) counts. Materials and Methods: NS whole oil, TQ and EGCG were administered before, with or after 7,12-dimethylbenza[a]anthracene (DMBA) painting the hamster left cheek pouch. Before sacrificing each animal, 2 ml of blood was withdrawn into a fine heparin-containing tube to estimate the total WBCs, lymphocytes, MID cells, and granulocytes counts by an automatic count system. All cheek pouches were surgically excised and examined with light microscope. Results: Severe epithelial dysplasia was evident after 6 weeks of DMBA administration, and when NS was given for 2 weeks followed by DMBA for 6 weeks. When NS or EGCG were given for 2 weeks then continued with DMBA for 6 weeks, mild dysplasia was seen. When DMBA was given for 6 weeks followed by NS or TQ for 6 weeks, mild dysplasia was noted. Administration of DMBA for 6 weeks resulted in significant reduction in total WBCs and lymphocytes counts compared to healthy controls. Administration of NS or TQ for 2 weeks resulted in significant elevation in lymphocytes count compared to healthy controls. Significant elevation in total WBCS and lymphocytes counts was noted when EGCG was given for 2 weeks and continued with DMBA for other 6 weeks. Similar results were noted when DMBA was given for 6 weeks followed by TQ for 6 weeks when compared to NS, DMBA or healthy controls. Discussion: The three phytochemicals showed different levels of protection against DMBA carcinogenic activity, more specifically, TQ and NS had higher therapeutic potential and might be used for treatment and/or preventive management of oral cancer in the future. Conclusion: However, further investigations are required to address the mechanism of action and feasibility of clinical application of each phytochemical.

Unraveling molecular mechanisms of Head and neck cancer

Malignancies that develop from mucosal epithelium of the upper aerodigestive tract are known as head and neck squamous cell carcinomas (HNSCC). Heterogeneity, late stage diagnosis and high recurrence rate are big hurdles in head and neck treatment regimen. Presently, the biomarkers available for diagnosis and prognosis of HNSCC are based on smoking as the major risk habit. This review shed light on the differential environment of HNSCC in smokeless tobacco consuming Indian patients. Frequent mutation in genes involved in DNA repair pathway (p53), cell proliferation (PIK3CA, HRAS) and cell death (CASP8, FADD) are common in western population. On the contrary, the genes involved in metastasis (MMPs, YAP1), lymphocyte proliferation (TNFRSF4, CD80), cell-cell adhesion (DCC, EDNRB), miRNA processing (DROSHA) and inflammatory responses (TLR9, IL-9) are mutated in Indian HNSCC patients. Gene ontology enrichment analysis highlighted that responses to chemical stimulus, immune pathways and stress pathways are highly enriched in Indian patients.

Functional impairment of infiltrating T cells in human colorectal cancer

T cells play a crucial role in preventing the growth and spread of colorectal cancer (CRC). However, immunotherapies against CRC have only shown limited success, which may be due to lack of understanding about the effect of the local tumor microenvironment (TME) on T cell function. The goal of this study was to determine whether T cells in tumor tissue were functionally impaired compared to T cells in non-tumor bowel (NTB) tissue from the same patients. We showed that T cell populations are affected differently by the TME. In the tumor, T cells produced more IL-17 and less IL-2 per cell than their counterparts from NTB tissue. T cells from tumor tissue also had impaired proliferative ability compared to T cells in NTB tissue. This impairment was not related to the frequency of IL-2 producing T cells or regulatory T cells, but T cells from the TME had a higher co-expression of inhibitory receptors than T cells from NTB. Overall, our data indicate that T cells in tumor tissue are functionally altered by the CRC TME, which is likely due to cell intrinsic factors. The TME is therefore an important consideration in predicting the effect of immune modulatory therapies.

Differences in oral habit and lymphocyte subpopulation affect malignant transformation of patients with oral precancer

BACKGROUND/PURPOSE

In Taiwan, the combination of betel quid chewing, alcohol consumption, and smoking habits increases oral cancer risk by 123-fold compared to persons without these habits. Lymphocyte populations in patients may potentially affect the malignant transformation of oral precancer.

METHODS

A total of 28 patients with oral precancer from our previous cohort were enrolled in this study, and their personal information and oral habits were documented. Their lymphocyte populations (CD4+, CD8+, CD19+, and CD56+) and activation markers (CD25 and CD69) were determined by flow cytometry from 1999 to 2004. After follow up till December 2014, data of patients with/without malignant transformation were recorded, and the relation between oral habits and percentage of initial lymphocyte markers was evaluated using the Student t test and Fisher's exact test.

RESULTS

Ten precancer patients developed oral squamous cell carcinoma with a mean period of malignant transformation of 6.8 ± 2.1 years. Patients with malignant transformation had a mean age of 48.4 ± 5.0 years (n = 10), relatively more than that of patients without malignant transformation (41.6 ± 6.3 years, n = 18) (p < 0.05). An increase was noted in the population of peripheral blood mononuclear cells expressing CD4+CD69+, CD19+CD69+, and CD56+CD69+ (p < 0.05) in precancer patients with malignant transformation. Alcohol consumption showed an association with the malignant transformation of patients with precancer (p = 0.030), whereas betel quid and smoking showed little effect.

CONCLUSION

These results suggest that age, alcohol consumption, and early activation of T cells, B cells, and natural killer cells are crucial in the malignant transformation of oral precancer. Analysis of patient's lymphocyte populations may help predict the malignant transformation of oral precancer.

Functional genetic variants of CTLA-4 and risk of tobacco-related oral carcinoma in high-risk North Indian population

Single nucleotide polymorphisms (SNPs) of the CTLA-4 gene have been implicated in susceptibility to different cancer in different ethnic populations. We assessed the association of five SNPs [-1722C/T, -1661A/G and -318C/T in the promoter region49A/G in exon 1 and CT60A/G in the 3'untranslated region (UTR)] with tobacco-related oral squamous cell carcinoma (OSCC) in North Indian subjects. We genotyped 130 OSCC patients and 180 normal subjects by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) using BbvI, MseI, NcoI and BstEII restriction endonucleases. Among these SNPs, -1722CC, -1661AG and CT60AA genotypes were more prevalent in OSCC patients as compared to controls and in the logistic regression analysis with odd ratio (OR) 2.85, 95% CI (0.69-11.68); OR 2.48, 95% CI (1.29-4.78) and OR 3.0, 95% CI (1.43-6.28) respectively, these genotypes showed strong association with OSCC risk. With higher prevalence in controls 49GG genotype and G allele (OR 0.57, 95% CI 0.40-0.81) appeared to be protective. Moreover, TACAG, TACGA and TATAG appeared as susceptible while TACGG and CACGG appeared as protective haplotypes. These results suggest significant risk modifying effects of CTLA-4 -1722C/T, -1661A/G, -318T/C, CT60 A/G and 49A/G SNPs in tobacco-related OSCC in North Indian population.

Infiltrating CD57+ inflammatory cells in head and neck squamous cell carcinoma: clinicopathological analysis and prognostic significance

This study investigated the immunodetection of CD57+ inflammatory cells in patients with head and neck squamous cell carcinoma (HNSCC) and its association with clinicopathological parameters and overall survival. Data collected from the morphological analysis and immunohistochemical reaction testing of archived HNSCC specimens (n=70) were statistically analyzed by bivariate and multivariate statistical testing at a significance level of P<0.05. The results indicate that CD57+ inflammatory cells predominate within the peritumoral stroma of HNSCC lesions and the existence of two significant relationships: between high CD57+ cell density and the development of a tumor of a large size [odds ratio (OR)=5.610, 95% confidence interval (CI)=1.516-20.763) and between high CD57+ cell density and the development of locoregional metastatic disease (OR=3.401, 95% CI=1.162-9.951). A significant difference in the rate of survival was detected only in HNSCC patients that presented large size tumors (OR=4.747, 95% CI=1.281-17.594). Together, these results suggest that although high CD57+ inflammatory cell density is associated with HNSCC lesions of greater clinical severity, the variable of cell density is not an independent predictor of HNSCC patient survival. Our findings also suggest that the relatively aggressive infiltration of CD57+ inflammatory cells in the peritumoral stroma of head and neck carcinomas may contribute to an ineffective locoregional antitumoral response.

Ex vivo triggering of T-cell-mediated immune responses by autologous tumor cell vaccine in oral cancer patients

We investigated immunomodulatory activity of autologous tumor cell vaccine from oral cancer patients ex vivo by lymphoproliferation assay and two color flow cytometry. Vaccine treatment lead to 10-fold higher proliferation of lymphocytes compared with the untreated controls. A significant increase in CD69(+) and HLA-DR(+) T-cells was observed in vaccine pulsed cultures compared with untreated (p<0.0001) controls. The frequency of IFN-gamma and IL-2 expressing CD4(+)/CD8(+)T-cell subsets was significantly higher with a concomitant reduction in IL-4 and IL-10 expression in the vaccine-treated group (p<0.0001) compared with the untreated controls. Vaccine treatment further increased T-cell receptor Vbeta3, Vbeta5, and Vbeta8 usage. It seems that the autologous tumor cell vaccine triggers T-cell responses ex vivo, hence it may have a protective role in oral cancer patients.

Differential regulation of IL-2 and IL-4 in patients with tobacco-related oral squamous cell carcinoma

AIM

The aim of the study was to investigate the systemic immunity in terms of major lymphocyte subsets and the expression of IL-2 and IL-4 in T-cell subsets from peripheral blood of patients with tobacco-related intraoral squamous cell carcinoma.

METHODS

CD3+, CD4+ and CD8+ T-cell subsets and CD16+ CD56+ natural killer cells, and intracellular cytokines in T-cell subsets were determined by two-colour flow cytometry and confocal microscopy.

RESULTS

Oral cancer patients showed a significantly reduced (P < 0.001) CD3+ and CD4+ T-cell subsets with a lower CD4/CD8 ratio when compared with the normal controls. The frequency of CD3+ IL-4+ and CD8+ IL-4+ T cells were significantly higher (P < 0.001) while CD4+ IL-2+ were significantly lower (P < 0.02) in patients when compared with the normal controls. Late stage of the tumour was associated with reduced expression of IL-2 in both CD4+ (P < 0.05) and CD8+ (P < 0.03) subsets.

CONCLUSIONS

The tobacco-related intraoral squamous cell carcinoma seems to be associated with multiple systemic immune defects particularly, an impaired CD3+ and CD4+ T cells in the peripheral blood as well as a differential regulation of IL-2 and IL-4 in CD4+ and CD8+ T-cell subsets. The cytokine response in these patients seems to be skewed from protective Th1 to immunosuppressive Th2 type. Thus these patients could be ideal candidate for immunomodulation therapy.

Triggering of T cell-mediated immune responses by allogenic tumor cell vaccine in patients with oral cancer

We investigated the immunomodulatory activity of allogenic whole tumor cell vaccine in oral cancer patients in vitro by two-color flow cytometry. Vaccine treatment significantly increased the expression of CD69 and HLA-DR in CD3+ T-cell subsets. The frequency of Interferon-gamma and Interleukin (IL)-2 expressing CD4+/CD8+ T-cell subsets was significantly higher with a concomitant reduction in IL-4 and IL-10 expressing T-cells in the vaccine treated group as compared with the untreated controls. Vaccine treatment significantly increased T-cell receptor (TCR), Vbeta3, Vbeta5 and Vbeta8 usage. The results indicate that the allogenic whole tumor cell vaccine is able to trigger T-cell mediated immunity in patients with intraoral squamous cell carcinoma.

Cell-mediated immunity and head and neck cancer: with special emphasis on betel quid chewing habit

Betel quid (BQ) chewing is popular in Taiwan, India, and many southeast-Asian countries. BQ chewing has strong association with the risk of oral leukoplakia (OL), oral submucous fibrosis (OSF), and oral cancer (OC). BQ components exhibit genotoxicity and may alter the structure of DNA, proteins and lipids, resulting in production of antigenicity. BQ ingredients are also shown to induce keratinocyte inflammation by stimulating the production of prostaglandins, TNF-alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) in keratinocytes. These events may provoke tissue inflammation, early cell-mediated immunity (CMI), and immune surveillance in BQ chewers. However, BQ components also directly affect the functional activities of immunocompotent cells, and moreover tumor cells may hypo-respond to the CMI via diverse mechanisms such as induction of apoptosis of lymphocytes, induction of production of suppressor T cells, downregulation of MHC molecules in tumor cells, etc. Clinically, an alteration in lymphocyte subsets, a decrease in total number of lymphocytes, and a reduction in functional activities of CMI have been observed in isolated peripheral blood mononuclear cells (PBMC) and tumor infiltrated lymphocytes (TIL) in patients with OSF, OL or OC. Adaptation of tumor cells to immune system may promote clonal selection of resistant tumor cells, leading to immune tolerance. Future studies on effects of BQ components on CMI and humoral immunity in vitro and in vivo can be helpful for chemoprevention of BQ-related oral mucosal diseases. To elucidate how virus infection, tobacco, alcohol and BQ consumption, and other environmental exposure affect the immune status of patients with oral premalignant lesions or OC will help us to understand the immunopathogenesis of OC and to develop immunotherapeutic strategies for OC.

Oral cancer: leukoplakia and squamous cell carcinoma

This article reviews the epidemiology, etiologic risk factors, clinical presentation, recognition, and diagnosis of oral precancer and cancer. The actual treatment and complications from treatment of oral cancer are discussed only briefly.

Disregulated expression of the Th2 cytokine gene in patients with intraoral squamous cell carcinoma

It has been seen that advanced stage oral squamous cell carcinoma is associated with impaired T-cell function and higher antibody response. In order to find out if such immune disregulation is associated with alteration of T-helper (Th) type CD4+ T-cell phenotype leading to altered cytokine production, we studied the Th-like cytokine profile in 35 oral squamous cell carcinoma patients and 21 normal controls. Concomitant expression of both Th1 and Th2 cytokine genes was studied by reverse transcription and Polymerase Chain Reaction (PCR) based amplification (RT-PCR) of mRNA extracted from freshly isolated peripheral blood mononuclear cells (PBMC) using specific primers for Interferon (IFN)-gamma, Interleukin (IL)-2, IL-4 and IL-10. Almost 63% of oral cancer patients showed polarization of a Th-like cytokine response as compared to 33% of the normal controls while 66.6% of normal controls showed a predominantly non-polarized Th0 response. Expression of IFN-gamma and IL-2 genes was more commonly seen in the early stage of the disease (p < 0.02) whereas majority of advanced stage tumours was associated with enhanced expression of IL-4 and IL-10 but not IFN-gamma and IL-2 genes. Patients with lymphnode metastases and poorly differentiated tumours expressed IL-4 and IL-10 more frequently with concomitant suppression of IFN-gamma and IL-2 genes. It seems therefore, that the development of oral squamous cell carcinoma leads to polarization of cytokine gene expression that is skewed towards the Th1-like response in the early stage. However, increasing tumour load and lymphnode invasion suppresses Th1 cytokine genes, thus skewing it toward a Th2-like cytokine response.

Tumor differentiation-dependent local immunity in human head and neck cancers

Distribution of markers of local cell-mediated immunity was examined in oral tumors exhibiting different histological stages of differentiation. Using a RT-PCR-based semiquantitative technique we determined levels of Langerhans cells, CD4- and CD8-positive T-cells, macrophages/NK cells, beta2-microglobulin and IFN-gamma mRNAs from tissue biopsies. A positive correlation was found between levels of these immunological markers and the tumor differentiation stage. Since tumor differentiation may correlate with the prognosis and response to various treatment modalities, our results may be useful clinically.

Nutritional support and prognosis in patients with head and neck cancer

We retrospectively studied the relationship between nutritional status as indicated by the presence or absence of the cutaneous delayed hypersensitivity response and treatment-related morbidity, disease recurrence, and survival at 2 years in 67 consecutive patients with head and neck carcinoma. Serial nutritional assessments were conducted throughout the course of combined initial antineoplastic treatment and nutritional support. The presence of cell-mediated immunity at the end of treatment was associated with a 2-year survival rate of 100%, whereas patients who were anergic at the end of treatment had a 2-year survival rate of 48% (P < 0.01). Morbidity due to surgical therapy and tumor recurrence rates were also higher in the anergic group (P < 0.01). Prognosis in head and neck cancer is based on many factors, but vigorous nutritional support during initial treatment may have some effect on morbidity, tumor recurrence, and survival time.