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Published on: February 25, 2016
Immunohistochemical study of inducible nitric oxide synthase in skin cancers
M Kagoura1, C Matsui, M Toyoda
1Department of Dermatology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan. kago@ms.toyama-mpu.ac.jp
Background:
Nitric oxide (NO) is synthesized from the amino acid L-arginine by NO synthase (NOS). Experimental evidence suggests that increased express of inducible NOS (iNOS), which is an NOS isoform and calcium independent, is related to various pathological processes, such as inflammation and cancer.
Methods:
In this study, we used immunohistochemistry to investigate iNOS expression in a series of basal cell carcinomas (BCC), Bowen's disease, squamous cell carcinomas (SCC), extramammary Paget's disease (EPD) and metastatic tumors of the skin.
Results:
Only 1 of 16 BCC cases was positive for iNOS and the intensity of staining was weak. In most of the 10 cases of Bowen's disease, iNOS was weakly expressed and there was a wide range in the percentage of positive tumor cells. Twelve of the 16 cases of SCC were positive for iNOS and the extent of positivity was greater than in Bowen's disease. Two of the 7 cases of EPD were positive for iNOS, and 12 of the 15 cases of metastatic cancer were positive. Well-differentiated adenocarcinomas were diffusely positive, whereas poorly-differentiated ones showed strong and heterogeneous staining.
Conclusions:
These results indicated that the expression of iNOS may reflect the proliferation of tumor cells and that a heterogeneous distribution of iNOS may correlate with a wide variety of biological behavior of tumor cells.
Insights
Inducible nitric oxide synthase (iNOS) expression varies across skin cancers. Higher iNOS levels in squamous cell carcinoma and metastatic tumors suggest a link to tumor cell proliferation and diverse biological behaviors.
Area of Science:
- Oncology
- Molecular Biology
- Immunology
Background:
- Nitric oxide (NO) is synthesized from L-arginine by NO synthase (NOS).
- Increased expression of inducible NOS (iNOS), a calcium-independent isoform, is linked to inflammation and cancer.
- iNOS plays a role in various pathological processes.
Purpose of the Study:
- To investigate the expression of iNOS in different types of skin tumors.
- To correlate iNOS expression with tumor characteristics and behavior.
Main Methods:
- Immunohistochemistry was used to detect iNOS expression.
- The study analyzed basal cell carcinoma (BCC), Bowen's disease, squamous cell carcinoma (SCC), extramammary Paget's disease (EPD), and metastatic skin tumors.
Main Results:
- iNOS was rarely detected in BCC.
- Weak iNOS expression was observed in Bowen's disease.
- SCC showed higher iNOS positivity than Bowen's disease.
- Metastatic cancers frequently expressed iNOS, with heterogeneous staining in poorly differentiated types.
Conclusions:
- iNOS expression may correlate with tumor cell proliferation.
- Heterogeneous iNOS distribution might indicate diverse biological behavior in tumor cells.
