nm23-H1 Expression Research Articles

Serum nm23-H1 Protein as a Prognostic Factor in Hematological Malignancies

A nondifferentiating mouse myeloid leukemia cell line produces differentiation-inhibiting factors. One of these factors was purified as a homologue of nm23. The nm23 gene was isolated as a metastasis-suppressor gene that exhibits low expression in high-level metastatic cancer cells. The nm23 gene was overexpressed in acute myelogenous leukemia (AML) cells and a higher level of nm23-H1 expression was correlated with a poor prognosis in AML. Multivariate analysis of putative prognostic factors revealed that elevated nm23-H1 mRNA levels significantly contributed to the prognosis of patients with AML. The overexpression of nm23-H1 was also observed in various hematological neoplasms. To use nm23 overexpression to determine the prognosis for lymphoma, we established an enzyme-linked immunosorbent assay (ELISA) technique to determine the serum level of nm23-H1 protein. This assay is far simpler than that used to determine nm23 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). Using this system, we measured nm23-H1 protein levels in many hematological malignancies. Serum nm23-H1 levels were significantly higher in patients with all of the hematological neoplasms tested (AML, chronic myelogenous leukemia, acute lymphoblastic leukemia, (ALL) myelodysplastic syndrome (MDS) and malignant lymphomas) than in normal controls. An elevated serum nm23-H1 protein concentration predicted a poor outcome for AML and non-Hodgkin's lymphoma. Especially in diffuse large B-cell lymphoma (DLBCL), serum nm23-H1 protein levels were an important prognostic factor in planning an appropriate treatment strategy for DLBCL. The serum nm23-H1protein levels probably depend on the total mass of malignant cells overexpressing nm23-H1.

The clinical significance of tumor angiogenesis and invasiveness-related gene expressions in gastric cancer

Objective: To investigate the correlation among tumor angiogenesis, expressions of p53, nm23-I1, CD44v6, c-erbB-2 proteins and biological behavior and clinical outcome of gastric cancer. Methods: The intratumoral microvessel density (MVD) and expressions of p53, nm23-H1, CD44v6, c-erbB-2 were analyzed semiquantitively by immunohistochemical staining (S-P) of 59 paraffin-embedded gastric tumor specimens that were radically resected at the Department of surgery, Beijing Institute for Cancer Research, between January 1990 and December 1992. The median follow-up period was 75 month (range: 60–96 months). The significdance of these indicators was analyzed retrospectively. Results: MVD for tumors with lymph node metastasis and vascular invasion was significantly higher than those without (P=0.0168 and 0.0176, respectively). The levels of p53, CD44v6, c-erbB-2 expression were significantly higher in the groups of lymph node metastasis, serosal infiltration and vascular invasion than in those without. All differences reached the statistically significant levels (P<0.01–<0.05). The low expression of nm23-H1 was negatively correlated with lymph node metastasis, serosal infiltration and vascular invasion (P<0.01; <0.05 and <0.01, respectively). Univariate analysis showed that the overall survival of patients with higher MVD, or overexpressions of p53, CD44v6, c-erbB-2, or low expression of nm23-H1 were significantly worse than those with opposite conditions (P=0.0214, 0.0062, 0.0045, 0.0159, and 0.0162, respectively). Multivariate analysis showed that expression of p53 in this series was an independent prognostic indicator. Conclusion: The data suggested that the above-mentioned factors might be helpful in evaluating the metastatic potential of gastric cancer and making more effective assessment of prognosis for individual patient. Further study with larger samples and prospective investigation of these results would be worthwhile.

Nm23-H1 gene as a molecular switch between the free-floating and adherent states of gastric cancer cells

The contribution of the nm23-H1 gene to metastasis in malignant tumors, including gastric cancer, is controversial. In this study, we compared nm23-H1 levels in two cell subtypes with different morphologies (floating and adherent states), but that were derived from the same gastric cancer cell line, KATO-III. A real-time quantitative reverse transcription-polymerase chain reaction showed that the number of nm23-H1 mRNA molecules in floating cells was significantly higher than that in adherent cells ( P<0.0001). The average of the copies in floating cells was approximately 2.4-fold higher than that in adherent cells. Consistent with mRNA levels, intracellular levels of nm23-H1 protein were higher in floating cells than in adherent cells. There was no difference in cell cycle characteristics between the two subtypes. In conclusion, our present data indicate that expression of nm23-H1 by a tumor could be altered during the different steps in metastases, suggesting that nm23-H1 may act as a molecular switch between the free-floating and adherent states of cancer cells.

Expression of p16, nm23-H1, E-cadherin, and CD44 gene products and their significance in nasopharyngeal carcinoma.

The present study was aimed to determine whether p16/MTS1, nm23-H1, E-cadherin, and CD44 proteins were expressed in nasopharyngeal carcinoma (NPC) and whether those expressions were pathologically significant in the progress of NPC. We examined non-cancerous nasopharyngeal mucosa (20 cases) and NPC (80 cases) using immunohistochemistry with six different types of monoclonal antibodies against p16, nm23-H1, E-cadherin, CD44H, CD44v3, and CD44v6 proteins. The results showed that 1) the rates of positive p16 protein expression and of preserved E-cadherin protein expression in NPC were significantly lower than those in non-cancerous tissue (P <.01); 2) no significant difference in the rate of positive expression of nm23-H1, CD44H, CD44v3, and CD44v6 proteins were observed between non-cancerous nasopharyngeal mucosa and NPC; 3) no significant difference in the expression of those proteins were found by respective correlation analyses of sex, stage, and size of primary tumor in NPC; and 4) no significant difference in the rates of positive expression of CD44H, CD44v3, and CD44v6 proteins were observed in NPC between with and without lymph node metastasis, indicating that those gene products did not correlate with lymph node metastasis in NPC. However, there were inverse correlations between the expression of p16, nm23-H1, or E-cadherin protein and lymph node metastasis (P <.05), indicating that the expression of p16, nm23-H1, and E-cadherin gene were related to the carcinogenesis and tumor progression of NPC. Detecting the expressions of those gene products may provide clinically valuable information for therapeutic strategy and for predicting the prognosis of patients with NPC.

Nm23-H1 immunoreactivity as a prognostic factor in differentiated thyroid carcinoma.

Several prognostic factors have been proposed to identify the patients at risk to develop metastases in differentiated thyroid carcinoma. Reduced nm23-H1 expression (a metastatic suppressor gene) has been correlated with high tumor metastatic potential in various human carcinomas, but the results obtained in differentiated thyroid carcinoma remain controversial. To elucidate the usefulness of nm23-H1 as a differentiated thyroid carcinoma prognosis factor, we evaluate the relationship between nm23-H1 immunoreactivity as well as both clinical status and patient outcome. For this purpose, thyroid resected specimens obtained from 94 differentiated thyroid carcinoma consecutive patients (64 papillary and 30 follicular) with at least 5 yr of follow-up were stained using monoclonal antibody to nm23-H1. We did not observe any relationship between nm23-H1 immunoreactivity and age, gender, initial differentiated thyroid carcinoma stage, local recurrence, or distant metastases in patients with papillary carcinoma. However, in patients with follicular carcinoma, a significant inverse association between metastatic disease and the expression of nm23-H1 product was obtained (P < 0.05). In addition, significant differences were found in the survival curves according to nm23-H1 immunoreactivity (log-rank P < 0.01). Finally, nm-23-H1 immunoreactivity was more specific but less sensitive than AMES score to predict metastases. In conclusion, our results suggest that nm23-H1 immunostaining could be added to the classic prognostic factors currently used to predict the outcome of patients with follicular thyroid carcinoma.

Expression of nm23-H1 in Hydatidiform Mole and Its Relationship with the Development of Postmolar Disease

The aim of the present study was to investigate the expression of nm23-H1 in human placenta, hydatidiform mole and choriocarcinoma cells. Nm23-H1 protein was localized in the cytotrophoblast, but not in the syncytiotrophoblast. In the hydatidiform mole cases with subsequent spontaneous remission, nm23-H1 mRNA levels were significantly lower than those in first-trimester placentas. However, its levels were elevated in the hydatidiform mole cases that progressed to persistent gestational trophoblastic disease and were comparable to those of first-trimester placentas, and they were further elevated in choriocarcinoma cells. The present data suggest an association of nm23-H1 for the proliferation activity of trophoblast, and its increased expression may influence the development of persistent trophoblastic disease.

Differential expression of metastasis-associated genes in papilla of vater and pancreatic cancer correlates with disease stage.

Papilla of Vater cancer has a much better prognosis than pancreatic cancer. It is not known whether this is the result of differences in the tumor biology of the two malignancies. Because metastasis formation is a critical step in tumor progression and a negative prognostic factor, we compared the expression of nm23-H1 and KAI1, two metastasis-suppressing genes, in papilla of Vater cancer and pancreatic cancer. Analysis was performed in nine normal human papilla of Vater samples, 27 papilla of Vater cancers, 16 normal pancreatic samples, and 29 pancreatic cancers. Expression of nm23-H1 and KAI1 was analyzed by Northern blot analysis and in situ hybridization. In addition, immunohistochemistry was performed to localize the respective proteins. There was no difference in nm23-H1 and KAI1 mRNA expression levels in normal versus cancerous papilla of Vater samples. In contrast, nm23-H1 and KAI1 RNA expression was upregulated in early tumor stages of pancreatic cancer and reduced in advanced tumor stages. When expression of nm23-H1 and KAI1 RNA was analyzed by use of in situ hybridization, normal epithelial cells of the papilla of Vater exhibited mRNA staining intensity similar to that of papilla of Vater cancer cells. Similar levels of nm23-H1 and KAI1 immunoreactivity also were observed in these samples. In contrast, early stage pancreatic cancer samples exhibited stronger nm23-H1 and KAI1 immunoreactivity than normal controls. Furthermore, early pancreatic cancer stages exhibited higher KAI1 and nm23-H1 immunostaining than advanced tumor stages. Differences in the expression patterns of the two tumor suppressor genes nm23-H1 and KAI1 may contribute to the different prognoses of papilla of Vater cancer and pancreatic cancer. Our findings support the hypothesis that biologic differences rather than earlier diagnosis influence the different outcomes of these two tumor entities.

Nm23-H1 Suppresses Invasion of Oral Squamous Cell Carcinoma-Derived Cell Lines without Modifying Matrix Metalloproteinase-2 and Matrix Metalloproteinase-9 Expression

nm23-H1 is a candidate gene for the suppression of cancer metastasis. Several studies on human breast, hepatocellular, gastric, ovarian, and colon carcinomas and melanomas have shown that reduced nm23-H1 expression was closely related to metastatic progression with poor prognosis. However, the biochemical mechanism by which nm23-H1 suppresses the metastasis has yet to be elucidated. In this study, we analyzed the correlation between nm23 expression, cell motility, and the invasive abilities of six different oral squamous cell carcinoma cell lines (HSC2, HSC3, HSC4, KB, OSC19, and OSC20). Reduced mRNA/protein expression of the nm23-H1 was observed in three cell lines (HSC2, HSC3, and HSC4). These cell lines exhibited increased cell motility and an invasive character on organotypic raft culture. On the other hand, the cell lines (KB, OSC19, and OSC20) that showed a higher expression of nm23-H1 exhibited a threefold to fivefold reduced motility and also reflected fewer invasions compared to the former three cell lines. Because the HSC3 cells demonstrated the lowest nm23-H1 expression with the highest cell motility and invasive character, we established nm23-H1-transfected HSC3 cell lines to investigate whether exogenous nm23-H1 protein could inhibit cell migration and invasive activity. These transfectants showed a significant reduction in cell motility with exogenous nm23-H1 in a dose-dependent manner, and exhibited a noninvasive character. An immunofluorescence study demonstrated a distinct stress-fiber distribution at peripheral region of these transfectants. However, no significant difference of matrix metalloproteinase (MMP)-2 and MMP-9 expression was observed between mock transfectant and nm23-H1-transfected cells. These findings suggest that nm23-H1 inhibits the invasive activity of oral squamous cell carcinoma by suppression of cell motility without altering the MMP-2 and MMP-9 status.

Establishment of rat hepatocellular carcinoma cell lines with differing metastatic potential in nude mice

For better understanding of cancer metastasis, we have established an in vivo model for induction of highly metastatic hepatocellular carcinomas (HCC) in male F344 rats. From 1 tumor, 4 cell lines with differing metastatic potential (C1, C2, C6, C5F) were established by subcloning using the limited-dilution cloning technique. Two other lines, N1 and L2, arose from another primary HCC and a lung metastatic lesion, respectively. Although cell adhesion of each cell line in culture medium was different, tumors developing in the subcutis of nude mice after transplantation were all moderately differentiated HCC with a trabecular pattern. On subcutaneous injection into nude mice, all 6 cell lines proved to be tumorigenic in the injection site and C5F was highly metastatic to the lung. With injection into the tail vein, N1 and L2 formed frequent metastases in the lung as well as in lymph nodes. Using intraperitoneal injection, C1, C6, N1 and L2 showed marked disseminated growth in the abdominal cavity with bloody ascitis. Northern blot analysis revealed expression of known metastasis-related genes, KAI1 and heparanase, to be decreased in C5F, but no differences in expression of nm23-H1 were evident. A point mutation in the GSK-3beta phosphorylation site of the beta-catenin gene was found in L2. These transplantable HCC cell lines that have different metastatic ability should be useful for elucidation of mechanisms of metastasis.

Expression of nm23-H1 in transitional cell carcinoma of the upper urinary tract.

Transitional cell carcinoma of the upper urinary tract is an uncommon neoplasm. Relatively little information is available regarding the clinical relevance of molecular markers. This study was performed to examine the importance of nm23-H1 gene expression (NM23-H1) in this type of tumors. Immunohistochemical expression of NM23-H1 was analyzed in 90 cases of upper urinary tract cancer, and was compared for its prognostic significance with conventional biological indicators. High expression of NM23-H1 was found in 7 cases (8%), intermediate expression in 32 cases (36%), and low expression in 51 cases (57%). Reduced NM23-H1 (defined as intermediate or low level of expression) was associated with a higher histological grading (p=0.002), invasive tumor growth (p=0. 002), or an increased proliferating cell nuclear antigen labeling index (p=0.004). NM23-H1 tended to inversely relate to later recurrence or long-term survival (p=0.06), but, only tumor staging was found to be significant in predicting clinical outcome (p=0.002). nm23-H1 appears to function as a tumor suppressor for upper urinary tract cancer, however, evaluation of NM23-H1 provides limited prognostic information.

Establishment of rat hepatocellular carcinoma cell lines with differing metastatic potential in nude mice

For better understanding of cancer metastasis, we have established an in vivo model for induction of highly metastatic hepatocellular carcinomas (HCC) in male F344 rats. From 1 tumor, 4 cell lines with differing metastatic potential (C1, C2, C6, C5F) were established by subcloning using the limited-dilution cloning technique. Two other lines, N1 and L2, arose from another primary HCC and a lung metastatic lesion, respectively. Although cell adhesion of each cell line in culture medium was different, tumors developing in the subcutis of nude mice after transplantation were all moderately differentiated HCC with a trabecular pattern. On subcutaneous injection into nude mice, all 6 cell lines proved to be tumorigenic in the injection site and C5F was highly metastatic to the lung. With injection into the tail vein, N1 and L2 formed frequent metastases in the lung as well as in lymph nodes. Using intraperitoneal injection, C1, C6, N1 and L2 showed marked disseminated growth in the abdominal cavity with bloody ascitis. Northern blot analysis revealed expression of known metastasis-related genes, KAI1 and heparanase, to be decreased in C5F, but no differences in expression of nm23-H1 were evident. A point mutation in the GSK-3beta phosphorylation site of the beta-catenin gene was found in L2. These transplantable HCC cell lines that have different metastatic ability should be useful for elucidation of mechanisms of metastasis.

Reappraisal of the role of NM23-H1 in colorectal cancers.

A number of evidence indicate that downregulation of the nm23-H1 gene may be relevant to metastatic progression of many kinds of human cancer. However, its role in colorectal cancers remains controversial. To address the issue, this study was performed to investigate the clinical relevance of nm23-H1 in patients with colorectal cancers. Immunohistochemical expression of nm23-H1 protein product (NM23-H1) was studied in a total of 146 colorectal cancer patients and compared for its prognostic value at a mean follow-up of 54 months. There was no apparent correlation between NM23-H1 expression and clinicopathological indicators, including Dukes category, lymphatic metastasis, distant metastasis, histological grading, and tumor location (P < 0.1, respectively). In addition, determination of NM23-H1 expression status did not provide independent prognostic information compared with conventional pathological staging. The results indicate that nm23-H1 gene does not play an important part in the progression of colorectal carcinogenesis.

Downregulation of intracellular nm23-H1 prevents cisplatin-induced DNA damage in oesophageal cancer cells: possible association with Na(+), K(+)-ATPase.

Previously, we showed that expression of nm23-H1 is associated inversely with sensitivity to cisplatin in human oesophageal squamous cell carcinoma (OSCC). The present study was undertaken to investigate the association of nm23-H1 expression with cisplatin-induced DNA damage in OSCC using antisense nm23-H1 transfectants. YES-2/AS-12, an antisense nm23-H1-transfected OSCC cell line, showed significantly reduced expression of intracellular nm23-H1 protein compared with that in parental YES-2 cells and YES-2/Neo transfectants. Surface expression of nm23-H1 protein was not observed in any of the three cell lines. PCR analysis for DNA damage demonstrated that YES-2/AS-12 cells were more resistant to nuclear and mitochondrial DNA damage by cisplatin than were YES-2/Neo cells. In addition, mitochondrial membrane potentials and DNA fragmentation assays confirmed that YES-2/AS-12 was more resistant than YES-2/Neo to apoptosis induced by cisplatin. In contrast, YES-2/AS-12 was more sensitive to ouabain, a selective inhibitor of Na+, K+-ATPase, than YES-2 and YES-2/Neo. Pre-treatment with ouabain resulted in no differences in cisplatin sensitivity between the three cell lines examined. Intracellular platinum level in YES-2/AS-12 was significantly lower than that in YES-2 and YES-2/Neo following incubation with cisplatin, whereas ouabain pre-treatment resulted in no differences in intracellular platinum accumulations between the three cell lines. Our data support the conclusion that reduced expression of intracellular nm23-H1 in OSCC cells is associated with cisplatin resistance via the prevention of both nuclear and mitochondrial DNA damage and suggest that it may be related to Na+, K+-ATPase activity, which is responsible for intracellular cisplatin accumulation. © 2000 Cancer Research Campaign

The Relationship Between the Expression of nm23-H1 and Lymph Node Metastasis in Colorectal Carcinoma

To study the relationship between the expression of nm23-H1 and lymph node metastasis in colorectal carcinoma.Methods The expression of nm23-H1 gene product was examined immunohistochemically in resected colorectal carcinomas.Results In tumors with weak immunoreactivity againt nm23-H1,frequency of lymph node metastasis was significantly higher than those with moderate or strong staining( P 0 05).With a sensitivity of 88 4% and specificity of 79 3%,low nm23-H1 immunoreactivity in primary tumor is an indicator of the presence of lymph node metastasis.Conclusion Immunohistochemical evaluation of nm23-H1 in the primary tumor is useful predictor of presence of lymph node metastasis in colorectal carcinomas and may have clinical significance in predicting optional therapetic regimes.

Relationship between expression of nm23-H1 and differentiation, metastasis of pulmonary carcinoma

Relationship between expression of nm23-H1 and differentiation, metastasis of pulmonary carcinoma

Schedule dependent toxicity and efficacy of combined gemcitabine/paclitaxel treatment in mouse adenocarcinoma

The effects of all-trans retinoic acid (ATRA) and epidermal growth factor (EGF) on the expression of nm23-H1, a metastasis suppressor gene, were studied in a human 7721 hepatocarcinoma cell line. It was discovered that the expression of nm23-H1 mRNA was up-regulated by ATRA. This was compatible with the observation that the metastasis-associated phenotypes, such as chemotaxic cell migration and invasion, were both reduced in the ATRA-treated and nm23-H1-cDNA-transferred 7721 cells. However, ability of cells to adhere to fibronectin and laminin was not altered identically in the ATRA-treated and nm23-H1-cDNA-transfected 7721 cells. In contrast, the expression of nm23-H1 mRNA in 7721 cells was down-regulated both by the treatment with EGF and by the transfection of c-erbB-2/neu cDNA, which codes a protein homologous to the EGF receptor. EGF is a compound with biological effects opposite to those of ATRA, and c-erbB-2/neu is known to be a metastasis-promoting gene. These results reveal that the metastasis-preventing effect of ATRA may partly result from the up-regulation of nm23-H1, and the metastasis-promoting effects of EGF and c-erbB-2/neu were probably mediated in part by the down-regulation of nm23-H1.

Negative regulation of the antimetastatic gene Nm23-H1 by thyroid hormone receptors.

Metastasis of various malignant cells is inversely related to the abundance of the Nm23-H1 protein. The possible role of thyroid hormones in tumor metastasis has now been investigated by examining the effect of T3 on the expression of the Nm23-H1 gene. Human hepatoma HepG2 cells, in which endogenous thyroid hormone receptor subtype alpha1 (TRalpha1) is expressed at a low level, were stably transfected, either with expression plasmids encoding wild-type TRalpha1 or a dominant negative mutant of TRalpha1, or with the empty vector (yielding HepG2-Wt, HepG2-Mt, and HepG2-Neo cells, respectively). Immunoblot analysis revealed that exposure of HepG2-Wt and HepG2-Neo cells, but not HepG2-Mt cells, to T3-induced time-dependent decreases in the abundance of Nm23-H1 messenger RNA and protein, with the extent of these effects correlating with the level of expression of TRalpha1. An in vitro assay also revealed that T3 induced a marked increase in the invasive activity of HepG2-Wt cells; it induced a smaller increase in that of HepG2-Neo cells but had no effect on that of HepG2-Mt cells. Finally, the promoter region of Nm23-H1 spanning nucleotides -471 to -437 (relative to the transcriptional initiation site) inhibited the expression of a downstream reporter gene, in a T3-dependent manner, in COS-1 cells also transfected with an expression plasmid encoding TRalpha1 or TRbeta1. The DNA binding domain of TRbeta1 was required for this inhibitory effect. These results indicate that T3, acting through TRs, inhibits transcription of Nm23-H1, and that this effect is mediated by a negative regulatory element in the promoter region of the gene. Thus, it is possible that T3 promotes tumor metastasis by inducing down-regulation of Nm23-H1 expression.

Nm23-H1 expression defines a high-risk subpopulation of patients with early-stage epithelial ovarian carcinoma.

The role of the nm23 gene in human ovarian cancer is still controversial. We studied the expression of the nm23-H1 gene in 247 human epithelial ovarian carcinomas. The patients were followed-up until their death, or for a minimum of 5 years if they survived. The expression of the gene was studied by means of immunohistochemistry and a semiquantitative scoring system considering the staining intensity and the number of reactive tumour cells. Patients carrying tumours with higher expression scores (4–6 on a scale from 0 to 6) had a significantly lower survival (P = 0.01) than the rest. Further stratified statistical analysis revealed that this effect was mainly attributable to the subgroup of patients with early-stage (I and II), well- and moderately differentiated tumours. In fact, a multivariate analysis carried out for this subset of patients showed nm23-overexpression to be the only significant independent predictor of an ominous prognosis. The association of nm23-overexpression with a worse prognosis was most probably not due to mutation of the nm23 gene, since mutational analysis in 60 tumours by means of single-strand conformational polymorphism and direct sequencing disclosed only one mutation, which was located outside the open reading frame. Our results seem to indicate that nm23 expression is associated with a significantly worse prognosis in early-stage, well-differentiated epithelial ovarian carcinoma, a finding with important clinical implications, considering that many patients with ovarian cancers showing these features do not undergo any further treatment beyond surgical staging. If confirmed, they could help in tailoring the treatment of these patients in the future. © 2000 Cancer Research Campaign

ORIGINAL ARTICLE H-ras and Nm23-H1 Gene Expression and Proteolytic Activity in Squamous Cell Carcinoma of the Uterine Cervix

Background The invasive and metastatic potential of malignant cells results from complex interactions of numerous factors not yet fully understood. Genomic alterations such as ras overexpression and nm23-H1 inhibition have been found to be frequently associated with increased invasiveness in various cancers. On the other hand, secretion of different proteinases are necessary for malignant cells to traverse a network of matrix macromolecules, but the relationship between the genomic alterations and the proteolytic phenotype is still unclear. Our aim was to investigate whether the appearance of the proteolytic phenotype had any correlation with the expression of H-ras and nm23-H1 genes in carcinoma of the uterine cervix. Methods Twenty-five samples from patients with carcinoma of the uterine cervix at different clinical stages were studied. Cathepsin B1, plasminogen activator, and collagenase activity were assessed in tissue cytosols using specific synthetic oligopeptides as substrates. The expression of H-ras and nm23-H1 was investigated by means of immunohistochemistry and in situ hybridization. Results Our results showed that cathepsin B1 was the most consistently elevated proteinase, demonstrating a linear correlation with clinical staging. H-ras expression was found elevated in 40% of the cases. Nm23-H1 protein immunoreactivity was positive in 40% of the cases. No correlation was found among H-ras, cathepsin B1 activity, and survival rate. Among cases with high cysteine proteinase activity, a different clinical behavior depending on the expression of Nm23-H1 was observed. The cases with Nm23-H1 protein had a markedly better survival rate than those lacking this protein. In contrast, the absence of Nm23-H1 in association with high cathepsin B1 activity was a clear indicator of a poor prognosis. Conclusions These findings suggest a complex interaction between the proteolytic phenotype and the expression of H-ras and nm23-H1 genes in carcinoma of the cervix that influences the clinical behavior of the tumor.

Increased activity of nm23-H1 gene in squamous cell carcinoma of the head and neck is associated with advanced disease and poor prognosis.

The present study was undertaken to determine whether the nm23-H1 gene is expressed in squamous cell carcinoma of the head and neck (SCCHN) and whether the level of nm23-H1 protein or mRNA in cells vary as they progress to a more malignant phenotype. Of the 120 SCCHN studied 54 (45%) stained positively for nm23-H1 protein. Protein expression was significantly higher in more advanced stages of disease. Expression of nm23-H1 was significantly higher in cancer tissues than in normal, adjacent tissue, dysplasia, or carcinoma in situ. The nm23-H1 rate increased with progression of synchronous lesions from dysplasia to carcinoma in situ and finally to carcinoma (P<0.05). Northern blot analyses of tissues with various clinicopathological characteristics also revealed differences in nm23-H1 mRNA expression. When levels of nm23-H1 mRNA were compared to tumor stage, intensity of expression was found to be higher in stages 3 and 4 than stages 1 and 2 (P<0.01). Malignant tumors had a higher level of mRNA nm23-H1 expression than normal or premalignant tissues. The nm23-H1 negative patients survived significantly longer than nm23-H1 positive ones (P<0.05). To study the possible relationship between nm23-H1 gene expression and cell growth rate in tumor cells, the mRNA level in each tumor was compared to proliferative activity. The nm23-H1 gene expression levels were directly related to the [3H]thymidine labeling index in tumor cells (R=0.6681). Our results strongly indicate that the nm23-H1 gene is involved in progression of SCCHN. Together with results obtained on lung cancer, our observations suggest that increased expression of nm23-H1 in cancers of the upper aerodigestive tract may have different implications than elsewhere in the body.