Related Experiment Video

Updated: Aug 8, 2026

Identification of OTX1 and OTX2 As Two Possible Molecular Markers for Sinonasal Carcinomas and Olfactory Neuroblastomas
07:00

Identification of OTX1 and OTX2 As Two Possible Molecular Markers for Sinonasal Carcinomas and Olfactory Neuroblastomas

Published on: February 28, 2019

Expression of nitric oxide synthase in pleomorphic adenomas of the parotid

P A Brennan1, T Umar, J Buckley

  • 1Oral and Maxillofacial Surgery, Queen Alexandra Hospital, Portsmouth, UK.

The British Journal of Oral & Maxillofacial Surgery
|August 2, 2000
PubMed

Insights

Inducible nitric oxide synthase (iNOS) expression significantly increased in parotid pleomorphic adenomas compared to normal tissue. Endothelial nitric oxide synthase (eNOS) showed minimal changes, suggesting iNOS plays a role in these salivary gland tumors.

Area of Science:

  • Oncology
  • Pathology
  • Biochemistry

Background:

  • Nitric oxide (NO) has complex roles in solid tumors, exhibiting both inhibitory and tumor-promoting activities.
  • Understanding the specific roles of different nitric oxide synthase (NOS) isoforms is crucial for elucidating tumor pathology.

Purpose of the Study:

  • To investigate immunohistochemically the expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in pleomorphic adenomas of the parotid.
  • To compare the expression patterns of iNOS and eNOS in tumor tissue versus normal salivary gland tissue.

Main Methods:

  • Immunohistochemistry was employed to detect and quantify iNOS and eNOS expression.
  • The study analyzed 30 cases of parotid pleomorphic adenomas and compared them with normal salivary tissue.

Main Results:

  • A significant difference in iNOS staining was observed between tumor and normal tissues (P<0.0001).
  • Tumor epithelial cells showed iNOS staining in 29 out of 30 cases, with positive staining also noted in salivary ductal luminal cells.
  • eNOS staining was minimal in tumor epithelium and salivary duct cells, with mild staining observed in blood vessel endothelium in both tumor and normal tissues.

Conclusions:

  • The study indicates a significant upregulation of iNOS in parotid pleomorphic adenomas.
  • The findings suggest that iNOS, but not eNOS, is differentially expressed in these tumors, potentially contributing to their pathology.

More Related Videos

Nitropeptide Profiling and Identification Illustrated by Angiotensin II07:31

Nitropeptide Profiling and Identification Illustrated by Angiotensin II

Published on: June 16, 2019

Identifying, Diagnosing, and Grading Malignant Peripheral Nerve Sheath Tumors in Genetically Engineered Mouse Models08:57

Identifying, Diagnosing, and Grading Malignant Peripheral Nerve Sheath Tumors in Genetically Engineered Mouse Models

Published on: May 17, 2024

Related Concept Videos

Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Nitric Oxide Signaling Pathway01:28

Nitric Oxide Signaling Pathway

Nitric oxide (NO), an inorganic gas, acts as a potent second messenger in most animal and plant tissues. NO diffuses out of the cells that produce it and enters the neighboring cells to generate a downstream response. NO synthase (NOS) catalyzes NO production by the deamination of the amino acid arginine. There are three isoforms of NOS. Endothelial cells have endothelial NOS (eNOS), nerve and muscle cells have neuronal NOS (nNOS), and macrophages produce inducible NOS (iNOS) upon exposure to...