Expression of inducible nitric oxide synthase in carcinomas and sarcomas affecting the oral cavity

NOS2 as a prognostic biomarker for early-onset colorectal cancer based on public data and clinical validation analysis

Early-onset colorectal cancer (EOCRC) was characterized by strong aggressiveness and high malignancy. The aim of this study was to screen suitable biomarkers for patients with EOCRC. EOCRC from The Cancer Genome Atlas Program (TCGA) database and Gene Expression Mapping (GEO) database were used to screen biomarkers for prognosis and treatment guidance. Clinical samples were used to verify the expression situation of these candidate biomarkers. The results showed the immune-related gene nitric oxide synthase 2 (NOS2) was independently associated with the poor prognosis of EOCRC patients in both TGCA and GEO database. The Immune Dysfunction and Exclusion (TIDE) analysis showed that multiple immunotherapy signatures, such as TIDE, Exclusion, and CAF, were difference among EOCRC patients with different risk scores, and significantly correlated with the expression of NOS2. Sensitivity analysis of chemotherapy drugs showed that NOS2 was significantly correlated with several chemotherapy drugs, such as MG.132_1862, BMS.754807_2171, and GEN.317_1926. Clinical validation analysis showed that the expression of NOS2 and its related genes CXCL1 and CXCL2 were significantly decreased in EOCRC patients. The results suggested that NOS2 can be used as a potential biomarker for EOCRC, which can be used for prognosis and guidance of immunotherapy and chemotherapy.

EZH2 Inhibition to Counteract Oral Cancer Progression through Wnt/β-Catenin Pathway Modulation

Oral squamous cell carcinoma (OSCC) is one of the most common human malignancies worldwide. The molecular mechanisms of OSCC pathogenesis are still unknown; however, in recent years, several reports have focused on the role of enhancer of zeste homolog 2 (EZH2) in OSCC. Therefore, in this study we aimed to investigate the effects of GSK343, a selective EZH2 inhibitor, and its impact on the signaling pathways in OSCC, using an in vitro and in vivo orthotopic model. In the in vitro model, GSK343 (1, 10, and 25 μM) significantly decreased OSCC cell viability and cell migration through EZH2 inhibition, modulating NF-κB/IκBα pathway activation and eNOS, VEGF, and TGFβ expression, important markers of angiogenesis. In the in vivo model, GSK343 (5 mg/kg and 10 mg/kg) restored tongue tissue architecture and reduced tumor progression through EZH2 inhibition and Wnt/β-catenin signaling pathway modulation. Moreover, GSK343 reduced the expression of inflammatory mediators; eNOS and TGFβ, markers of angiogenesis; and CD31 and CD34, markers of micro vessel density, respectively. In conclusion, our data demonstrate that GSK343 counteracts oral cancer progression through EZH2/Wnt/β-catenin pathway modulation, suggesting that it could be a promising therapeutic approach for OSCC management.

Micrometastasis detection using modified papanicolaou stain in nodal tissues of oral squamous cell carcinoma - A histological study

CONTEXT

Cervical lymph node metastasis is the most important prognostic factor in Squamous Cell Carcinoma of Head and Neck (SCCHN). Detection and evaluation of micro-metastasis forms the basis for diagnosis, staging, treatment options and prognosis. Lymph node prognostic factors are extremely important for the survival and recurrence in the patient. Assessing lymph node metastasis in the absence of clinical enlargement is challenging.

AIM

To evaluate micrometastasis and individual tumor cells (ITC) in regional lymph nodes of oral squamous cell carcinoma (OSCC) by modified papanicolaou (PAP) stain and re-evaluate the tumor staging.

SETTINGS AND DESIGN

The retrospective study was executed at MS Ramaiah University of Applied Sciences.

METHODS AND MATERIALS

The current study constituted a total of 40 lymph nodes from OSCC patients, metastatic (n=20) and non-metastatic lymph nodes (n=20). All sections were stained with H & E followed by modified PAP stain. Modified PAP was used for identification of micrometastasis deposits.

STATISTICAL ANALYSIS USED

The Chi square test was employed to analyze significance.

RESULTS

Modified PAP stain proved to be more accurate (p = 0.006) than H and E stain in detecting micrometastasis which accounted for 15% of non-metastatic lymph node sections used in our study.

CONCLUSION

Special stain like modified PAP stain is valuable and sensitive in detecting micro-metastasis over H and E stain. Detection of micrometastasis in OSCC patients is advantageous for the patient as it influences staging, it modifies the treatment plan in terms of both radiotherapy and chemotherapy.

Immunology of Oral Squamous Cell Carcinoma-A Comprehensive Insight with Recent Concepts

This review aims to understand the concept of oral cancer immunology through the notion of immune profiling, immunoediting and immunotherapy, and to gain knowledge regarding its application for the management of oral cancer patients. Oral cancer is an immunogenic tumor where the cells of the tumor microenvironment play an important role in tumorigenesis. Understanding the mechanism of these modulations can help design immunotherapeutic strategies in oral cancer patients. This article gives an overview of immunomodulation in the oral cancer tumor microenvironment, with concepts of immune profiling, immunoediting and immunotherapy. English literature searches via Google Scholar, Web of Science, EBSCO, Scopus, and PubMed database were performed with the key words immunology, tumor microenvironment, cells, cross talk, immune profiling, biomarkers, inflammation, gene expression, techniques, immunoediting, immunosurveillance, tumor escape, immunotherapy, immune checkpoint inhibitors, vaccines in cancer, oral cancer, and head and neck cancer. Original research articles, reviews, and case reports published from 2016-2021 (n = 81) were included to appraise different topics, and were discussed under the following subsections. Literature published on oral cancer immunology reveals that oral cancer immune profiling with appropriate markers and techniques and knowledge on immunoediting concepts can help design and play an effective role in immunotherapeutic management of oral cancer patients. An evaluation of oral cancer immunology helps to determine its role in tumorigenesis, and immunotherapy could be the emerging drift in the effective management of oral cancer.

The expression profiles of chemokines, innate immune and apoptotic genes in tumors caused by Rous Sarcoma Virus (RSV-A) in chickens

Innate immune genes play an important role in the immune responses to Rous sarcoma virus (RSV)-induced tumor formation and metastasis. Here, we determined in vivo expression of chemokines, innate immune and apoptotic genes in Synthetic Broiler Dam Line (SDL) chickens following RSV-A infection. The mRNA expression of genes was determined at the primary site of infection and in different organs of progressor, regressor and non-responder chicks, using RT-qPCR. Our results indicated a significant upregulation of: (1) chemokines, such as MIP1β and RANTES, (2) the innate immune gene TLR4, and (3) p53, a tumor-suppressor gene, at the site of primary infection in progressor chickens. In contrast, inducible nitric oxide synthase (iNOS) gene expression was significantly downregulated in progressor chicks compared to uninfected, control chicks. All of the innate immune genes were significantly upregulated in the lungs and liver of the progressor and regressor chicks compared to control chicks. In the spleen of progressor chicks, RANTES, iNOS and p53 gene expression were significantly increased, whereas MIP1β and TLR4 gene expression was significantly downregulated, compared to control chicks. The lungs and livers of non-responder chicks expressed a low level of iNOS and MIP1β, whereas RANTES, TLR4, and p53 gene expression were significantly upregulated compared to uninfected control chicks. In addition, there was a significant downregulation of RANTES, MIP1β, and TLR4 gene expression in non-responder chicks. These results suggest the different response to infection of chicks with RSV-A is due to differential changes in the expression of innate immune genes in different organs.

Antioxidant-Oxidant Index as a Biomarker in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma: A Biochemical Study

INTRODUCTION

Oxidative stress has been implicated in tumourigenesis by affecting the actions of various protein kinases and transcription factors, and resulting in damage to DNA structure by the deamination of nucleotides and the generation of free radicals. Derangements in the antioxidant defence mechanism have been considered in the pathogenesis of oral cancer.

AIM

To evaluate and compare the serum levels of nitric oxide and vitamin C in cases of Oral Potentially Malignant Disorders (OPMDs) and Oral Squamous Cell Carcinoma (OSCC) and healthy controls.

MATERIALS AND METHODS

Serum from 20 patients with OSCC, 20 patients with OPMDs and 10 healthy subjects were analyzed for levels of nitric oxide and vitamin C using UV spectrophotometry. Antioxidant-Oxidant Index (AOI) was calculated by calculating the ratio between the levels of nitric oxide and vitamin C.

RESULTS

The mean nitric oxide levels were elevated in OSCC group, as compared to OPMD and control group, whereas, mean serum vitamin C levels were reduced in OSCC group as compared to OPMDs and control group (statistically significant, p<0.05). There was significant increase in AOI from control group (0.023), OPMDs (0.167) and OSCC group (0.279) (p<0.05).

CONCLUSION

Assessment of levels of antioxidant oxidant markers are useful tools in monitoring the progression of OPMDs to OSCC. AOI is an objective tool to assess the oxidative stress in these patients.

Quantitative measurement of iNOS expression in melanoma, nasopharyngeal, colorectal, and breast tumors of Tunisian patients: comparative study and clinical significance

Chronic inflammation increases the risk of development of human malignancies. iNOS is an enzyme dominantly expressed during inflammatory reactions and seems to play a critical role in tumorigenesis. Our aim was to assess the iNOS expression in four types of human tumors: breast, colorectal, nasopharyngeal, and melanoma, of Tunisian patients. The level of iNOS was measured by RT-QPCR in tumor specimens. We showed that the expression of iNOS was higher in breast compared to colorectal and nasopharyngeal tumors, whereas in melanoma, the level of iNOS expression was low. Significant associations were found when comparing the iNOS expression in cancers pairs such as melanoma versus colorectal (p < 0.0001), colorectal versus nasopharyngeal (p = 0.0072), and melanoma versus breast (p < 0.0001). Furthermore, iNOS expression correlated with the Breslow thickness, Clark level, and histological subtype in melanoma, while in nasopharyngeal carcinoma, significant association was seen with age at diagnosis, TNM, metastasis, response to treatment, and expression of COX-2. Furthermore, the expression of iNOS correlated with tumor size, TNM, tumor location, and histological type in colorectal cancer, and with tumor size, tumor stage, SBR grade, and triple negative cases in breast cancer. On the other hand, immunohistochemistry analysis shows that the expression of iNOS is observed in the stroma and tumor cells as well. Overall, our results highlight that iNOS is a reliable marker for advanced stage and aggressive behavior for the four types of cancer and might be a potential promising therapeutic target.

The dual role of iNOS in cancer

Nitric oxide (NO) is one of the 10 smallest molecules found in nature. It is a simple gaseous free radical whose predominant functions is that of a messenger through cGMP. In mammals, NO is synthesized by the enzyme nitric oxide synthase (NOS) of which there are three isoforms. Neuronal (nNOS, NOS1) and endothelial (eNOS, NOS3) are constitutive calcium-dependent forms of the enzyme that regulate neural and vascular function respectively. The third isoform (iNOS, NOS2), is calcium-independent and is inducible. In many tumors, iNOS expression is high, however, the role of iNOS during tumor development is very complex and quite perplexing, with both promoting and inhibiting actions having been described. This review will aim to summarize the dual actions of iNOS-derived NO showing that the microenvironment of the tumor is a contributing factor to these observations and ultimately to cellular outcomes.

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NO is pro- and anti-tumorigenic. High concentrations of NO maybe anti-tumorigenic.

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iNOS produces high concentrations of NO and relates to tumor growth or its inhibition.

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iNOS is associated with cytotoxicity, apoptosis and bystander anti-tumor effects.

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Tumor- and stromal-iNOS, and the ‘cell situation’ contribute to anti or pro-tumor effects.

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Dual role of iNOS is influenced by the cell situation and is environment dependent.