Nm23 expression in endometrial and cervical cancer: Inverse correlation with lymph node involvement and myometrial invasion

The expression of nm23 has been shown to correlate in some solid tumours with their metastatic potential and to be associated with a favourable prognosis in human breast cancer and melanoma. In breast and ovarian cancer nm23 expression is also correlated with lymph node involvement. We analysed the expression of nm23-H1 and -H2 in normal endometrium and in endometrial and cervical cancer by both Northern and Western blotting. Cellular localisation of Nm23-H1 was visualised by immunohistochemistry mostly in the cytoplasm. Both isoforms of Nm23 were present in all the samples analysed, and a clear direct correlation between Nm23-H1 and -H2 levels was evident. Median nm23-H2 levels were higher than than -H1 levels in both tissues. Cervical cancer patients with lymph node involvement were shown to have significantly lower protein levels of Nm23 (P<0.007 for H1 and P<0.009 for H2), and a similar trend was also evident in endometrial cancer. Furthermore, the degree of myometrial invasion in endometrial cancer patients was also inversely correlated with Nm23-H1 levels of expression (P<0.003). Nm23 level may therefore be taken into consideration as a new marker in the prognostic characterisation and in the treatment planning of uterine tumour patients.