Immunohistochemical localization of the NM23 protein in salivary gland neoplasms with distinct biological behavior

Abstract

The NM23 protein was shown to be associated with metastasis suppression in human malignancies with various tissue origins. However, its association with the metastatic phenotype of salivary gland neoplasms (SGN) remains unknown. To evaluate the role of NM23 in SGN, the expression patterns of NM23 in the following were compared: benign (pleomorphic adenoma) vs malignant (adenoid cystic carcinoma and mucoepidermoid carcinoma) SGN, and primary malignancies with/without evidence of metastasis vs their metastatic implants (MI). The lesions were studied immunohistochemically. NM23 protein was found in the cytoplasm of 75% of benign SGN, 73.3% of primary SGN malignancies with no evidence of metastasis, 86.6% of primary SGN malignancies with evidence of metastasis, and 60% of MI. There was no statistically significant difference in the frequency of NM23-positive cells between benign and primary malignant tumors (p = 0.79), nor between primary malignancies with/without evidence of metastasis and MI (p = 0.51). However, nuclear NM23 protein was restricted to primary SGN malignancies with evidence of metastasis and MI. The presence of nuclear NM23 protein may be a good marker for predicting the metastatic potential of SGN malignancies.

Expressão da proteína nm23 em carcinoma de células escamosas de língua metastático e não-metastático

“…Our results are similar to those of Göhring et al 22 in their 2002 paper, where nm23-h1 protein positivity was unrelated to metastatic breast carcinomas. On the other hand, our results disagree with those of Nascimento et al, 23 who investigated benign and malignant salivary gland neoplasms and found that the presence of the nm23 protein in the nucleus may be a good indicator for predicting the metastatic potential of salivary gland malignancies.…”

Advances in salivary gland pathology

“…Both reduced expression and overexpression of NM23 have been demonstrated to correlate with increased metastasis and poorer prognosis in cancers from different sites 12 . Cytoplasmic NM23 staining can be demonstrated in the majority of pleomorphic adenomas, adenoid cystic carcinomas and mucoepidermoid carcinomas, with no significant difference in the frequency of positive cells among these tumours 13 . However, nuclear expression of NM23 is restricted to malignant salivary gland tumours with metastasis 13 .…”

“…12 Cytoplasmic NM23 staining can be demonstrated in the majority of pleomorphic adenomas, adenoid cystic carcinomas and mucoepidermoid carcinomas, with no significant difference in the frequency of positive cells among these tumours. 13 However, nuclear expression of NM23 is restricted to malignant salivary gland tumours with metastasis. 13 Hence, nuclear NM23 staining may be used for predicting metastasis in salivary gland carcinomas.…”

“…13 However, nuclear expression of NM23 is restricted to malignant salivary gland tumours with metastasis. 13 Hence, nuclear NM23 staining may be used for predicting metastasis in salivary gland carcinomas.…”