Expression Levels Of nm23-H1 Research Articles

MiR-146a promoted breast cancer proliferation and invasion by regulating NM23-H1.

The study aimed to investigate the regulatory effect of miR-146a in proliferation, invasion and migration of breast cancer and its possible mechanism via NM23-H1. The expression levels of miR-146a in breast cancer with different pathological classification were significantly increased, while the expression levels of NM23-H1 were significantly decreased, which were closely correlated. Double luciferase reporter gene was used to verify the target regulatory relationship between miR-146 and NM23-H1 on a human breast cancer cell line. miR-146a was closely related to the proliferation and metastasis of breast cancer. miR-146a also promoted the growth of breast cancer in vivo via targeting NM23-H1. In conclusion, miR-146 can promote the proliferation and invasion of breast cancer by targeting NM23-H1.

Correlation of p16 and nm23-H1 expression levels with incidence and prognosis of soft tissue sarcoma.

The expression levels of p16 and nm23-H1 genes in soft tissue sarcoma (STS) were evaluated to investigate correlation of the expression levels with the incidence and prognosis of STS. Tumor tissues and para-carcinoma normal tissues were collected from 64 STS patients. The messenger ribonucleic acid (mRNA) expression levels of p16 and nm23-H1 in the tissues were detected via reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and the protein expression levels of p16 and nm23-H1 in tissues were detected using immunohistochemistry. Spearman's correlation analysis was used for the correlation between expression levels of p16 and nm23-H1 in STS tissues and the correlation between p16 and nm23-H1 mRNA and protein expression. Moreover, the correlation of p16 and nm23-H1 expression levels in tumor tissues with pathological parameters and prognosis of STS patients were analyzed combined with clinical data. Results of RT-qPCR showed that mRNA expression levels of p16 and nm23-H1 in tumor tissues of STS patients were significantly lower than those in para-carcinoma normal tissues (P<0.01). Results of immunohistochemistry showed that the positive expression rates of p16 and nm23-H1 in tumor tissues of STS patients (43.75 and 39.06% respectively) were significantly lower than those in para-carcinoma normal tissues (85.93 and 89.06% respectively). The expression of p16 and nm23-H1 mRNA was positively correlated with protein expression levels. There was a positive correlation between the expression levels of p16 and nm23-H1 in tumor tissues of STS patients. The negative expression of p16 in tumor tissues of STS patients correlated with tumor size, tumor metastasis and clinical staging, and the negative expression of nm23-H1 correlated with tumor metastasis and clinical staging. The overall 5-year survival rate of patients was 54.68%, and the prognosis of patients with positive expression levels of p16 and nm23-H1 was better. Univariate survival analyses revealed that p16 and nm23-H1 were influencing factors of the overall survival rate of STS patients. p16 and nm23-H1 expression in STS is low, and their expression levels are closely related to the pathological parameters and prognosis of STS patients, so they can serve as reference indexes for prognosis estimation of STS.

Expression of nm23-H1 and COX-2 in thyroid papillary carcinoma and microcarcinoma.

The expression of non-metastatic expressed/non-metastatic 23 nucleoside diphosphate kinase 1 (nm23-H1) and cyclooxygenase 2 (COX-2) proteins in thyroid carcinoma have been analysed in a number of previous studies, but this requires further study. The current study focused on the expression levels of nm23-H1 and COX-2 in 130 human thyroid papillary carcinoma (PTC) tissues. Of the 130 PTC tissues, 55 were classified as microcarcinoma and may provide information on the development of the specific characteristics of this tumour type. Routine histopathological examination and immunohistochemical detection of nm23-H1 and COX-2 expression was performed on 130 PTC tissues from patients treated in the Clinical Hospital for Tumours (Zagreb, Croatia) between January 2000 and December 2007. The stain intensity of nm23-H1 and COX-2 proteins was compared with the characteristics of the patients and the tumour. The highest overall expression rate of nm23-H1 and COX-2 was 90 and 67.6%, respectively, and the joint expression of these proteins was statistically significant. The median expression level of nm23-H1 was significantly increased in the classical and follicular histological group of the PTC tissues compared with tissues from other histological groups. The median expression level of COX-2 was significantly increased in the follicular histological group, and reduced in the diffuse-sclerosing group of PTC tissues. All the metastatic microcarcinoma tissues had increased expression levels of the two proteins in comparison with microcarcinoma tissues without lymph node metastases; however, this variation was only statistically significant for COX-2 expression levels. Therefore the results of the current study indicate that COX-2 protein levels may be able to differentiate which thyroid papillary microcarcinoma tumours possess metastatic potential.

Combined detection of the expression of Nm23-H1 and p53 is correlated with survival rates of patients with stage II and III colorectal cancer.

Molecular tumor markers hold considerable promise for accurately predicting the recurrence and progression of colorectal cancer (CRC) in patients. However, in the majority of cases, single marker analysis has been found to have low accuracy, and is of little practical use in clinical practice. The present study investigated the prognostic value of the combined detection of the protein expression of metastasis suppressor 23-H1 (Nm23-H1) and p53 using immunohistochemical analysis, and the mRNA expression levels were analyzed using reverse transcription-quantitative polymerase chain reaction in 110 cases of stage II and III CRC. The results revealed that the expression levels of Nm23-H1 in CRC tissues were lower, compared with those in normal tissues (χ2=18.249; P<0.001), and the protein expression levels of p53 were higher in the CRC tissues (χ2=23.940; P<0.001); although the mRNA expression levels of Nm23-H1 and p53 presented with the same trend. The protein expression of Nm23-H1 was correlated with lymph node metastases (χ2=11.847; P=0.001) and pathological patterns (χ2=6.911; P=0.032). However, it did not correlate with patient gender or age, or with tumor World Health Organization classification or invasive depth (P>0.05). No significant correlation was observed between the expression of p53 and clinicopathological features (P>0.05). Patients with CRC with Nm23-H1(+)/p53(−) tumors had increased survival rates, with a five-year overall survival rate of 83.8% and a five-year disease-free survival rate of 70.2%. The five-year overall survival rates in other study cohorts were lower, compared with the Nm23-H1(+)/p53(−) group (P<0.0125), and this was the same for the five-year disease-free survival rate (P<0.0125). In conclusion, the present study demonstrated that the combined detection of the protein expression of Nm23-H1 and p53 was associated with the long term survival rates of patients with stage II and III CRC; and this may offer potential for use as a predictor of survival rates in patients with CRC.

Mutation of the nm23-H1 gene has a non-dominant role in colorectal adenocarcinoma.

Nm23-H1 is a metastasis suppressor gene, which is has a reduced expression in patients with digestive system cancer. However, the mechanistic basis for the genetic instability remains unknown. To study the expression of the nm23-H1 gene in patients with colorectal cancer, polymerase chain reaction-single strand conformation polymorphism was used to analyze any point mutation, and immunohistochemistry was used to detect the expression of nm23-H1. Results revealed that all 63 specimens of Chinese human colorectal cancer tissues exhibit no point mutation. Among those 63 specimens, 19 (30%) exhibited positive immunostaining for the nm23-H1 protein and 44 (70%) exhibited negative immunostaining. These observations suggested that the protein and gene expression levels of nm23-H1 are reduced in colorectal cancer compared with the adjacent normal tissues, and the point mutation in the nm23-H1 gene is not the dominant cause of metastatic colorectal cancer.

A prognostic role for Nm23-H1 in laryngeal carcinoma treated with postoperative radiotherapy: an introductory investigation

Postoperative RT is generally recommended for laryngeal carcinomas (LSCCs) at high risk of recurrence after surgery. There are currently no clinicopathological parameters available to predict response to such adjuvant RT in LSCC, and only a few potentially predictive biomarkers have been investigated. Nm23-H1 protein is reportedly related to the tumor cells' metastatic potential, and low Nm23-H1 expression levels in human carcinomas often correlate with a poor prognosis. The novel aim of the present preliminary study was to investigate the prognostic value of Nm23-H1 expression and subcellular localization in a series of patients given postoperative RT for LSCC. A retrospective clinicopathological investigation was conducted at an academic tertiary referral center of 28 consecutive patients given postoperative RT for LSCC. Image analysis of immunohistochemical reactions was performed to measure Nm23-H1 total and nuclear expression levels. Disease-free survival (DFS) was significantly shorter among LSCC patients with total Nm23-H1 levels <50.0 % (p = 0.03); the mean total Nm23-H1 expression was lower in patients with recurrent disease than in patients without it (statistical trend, p = 0.07). The disease recurrence rate was significantly higher (p = 0.021) and the DFS shorter (statistical trend, p = 0.052) among LSCC patients with nuclear Nm23-H1 levels <5.0 %. The locoregional recurrence-risk ratio in LSCC patients with nuclear Nm23-H1 levels <5.0 % was 9.16. Nm23-H1 warrants further investigation of its potential role as a predictive biomarker with a view to providing tailored treatments after surgery, such as combinations of chemotherapy and RT instead of RT alone, in patients whose LSCCs have low or no Nm23-H1 expression.

Correlation of NM23-H1 cytoplasmic expression with metastatic stage in human prostate cancer tissue

Nm23-H1 has been identified as a metastatic suppressor gene in murine melanoma cell lines. Several functions have been attributed to its activity in cancer, including a histidine kinase activity, DNA repair, and regulation of other proteins involved in metastatic formation. While in breast cancer, NM23-H1 overexpression indicates a benign status through impairing progression of disease, its function is opposite in other cancers; e.g., neuroblastoma. To further understand this dichotomy of function in cancer, we have analyzed its function in prostate cancer, in which the relationship between NM23-H1 expression and prognostic state is today controversial. In vitro, overexpression of NM23-H1 in PC3 cells inhibited their cell motility, while downregulation of NM23-H1 expression in these cells by RNA interference showed enhanced cell motility. Immunohistochemistry analysis performed on 346 prostate cancer tissue samples showed a relationship between high levels of NM23-H1 expression in the nuclei of these tumorigenic cells and elevated Gleason score, with high levels of NM23-H1 cytoplasmic staining related to metastatic stage. This retrospective survival study demonstrates that high levels of NM23-H1 expression in the cytoplasm determine recurrence of prostate-specific antigen levels only in those patients with metastatic disease. Our findings suggest a correlation between high levels of NM23-H1 protein in the cytoplasm of the cells and progression of prostate cancer to metastasis, thus definitively identifying NM23-H1 as a new negative prognostic marker in prostate cancer.

Transcatheter arterial chemoembolizaion on the expression of nm23, Tissue inhibitor of metalloproteinase-2 and extrahepatic metastasis in hepatocellular carcinoma

Objective To investigate the effects of transcatheter arterial chemoembolization(TACE) on the expression of nm23, tissue inhibitor of metalloproteinase-2 (TIMP-2) and extrahepatic metastasis in hepatocellular carcinoma (HCC). Methods The specimens were collected from resectable HCC in 72 patients. Patients were divided into two groups. In one group, TACE was performed before tumor resection (Group A, n=36). In another group, the tumors were resected directly without preoperative TACE (Group B, n=36). The expression and distribution of nm23, TIMP-2 in the tumor tissue and liver parenchyma in the two groups were compared. All patients were followed up for 24 months,and the incidence of extrahepatic metastasis was compared between the two groups. Chi-square test was applied to compare the expression levels of nm23-H1 and TIMP-2. Results The number of cases of strong, moderate and no expression of nm23 were 24, 6 and 6 cases in group A respectively, and were 9, 6 and 21 cases in group B. Statistical differences were found between the two groups(X~2=15.52, P 0.05). Conclusions TACE could enhance the expression of nm23-H1 and TIMP-2 in tumor tissues. Therefore, the potential of metastasis of tumor cells might be prohibited by TACE. Key words: Carcinoma,hepatocellular; Neoplasm metastasis; nm23-H1; Tissue inhibitor ofmetalloproteinase-2

Nm23‐H1 modulates the activity of the guanine exchange factor Dbl‐1

Cytoskeleton rearrangement is necessary for tumor invasion and metastasis. Cellular molecules whose role is to regulate components of the cytoskeletal structure can dictate changes in cellular morphology. One of these molecules is the suppressor of tumor metastasis Nm23-H1. The level of Nm23-H1 expression has been linked to the invasiveness and metastatic potential of human cancers including melanoma and breast cancer. In this report, we demonstrate an interaction between the suppressor of tumor metastasis Nm23-H1, and Dbl-1, an oncoprotein which is associated with guanine exchange and belongs to a family of Guanine Exchange Factors (GEF). Nm23-H1 also was shown to bind pDbl which is the proto-oncoprotein of Dbl. Interestingly, the interaction between Nm23-H1 and Dbl-1 rescues the suppression of the cell motility activity Nm23-H1. Moreover, this interaction results in loss of the ability of the Dbl-1 oncoprotein to function as a GEF for the critical Rho-GTPase family member Cdc42. The loss of GTP loading onto Cdc42 resulted in a dramatic reduction in adhesion stimulated ruffles and suggests that Nm23-H1 can negatively regulate cell migration and tumor metastasis by modulating the activity of Cdc42 through direct interaction with Dbl-1.

Nm23-H1 Metastasis Suppressor Expression Level Influences the Binding Properties, Stability, and Function of the Kinase Suppressor of Ras1 (KSR1) Erk Scaffold in Breast Carcinoma Cells

Metastatic disease is a significant contributor to cancer patient mortality. We previously reported that the Kinase Suppressor of Ras1 (KSR1) scaffold protein for the Erk mitogen-activated protein kinase pathway coimmunoprecipitated the metastasis suppressor protein Nm23-H1. We now hypothesize that altered expression levels of Nm23-H1 influence the binding properties, stability, and function of the KSR1 scaffold. Increased coimmunoprecipitation of Hsp90 with KSR1 was observed in either stable or transient transfectants of nm23-H1 in MDA-MB-435 human breast carcinoma cells. Similar trends were also observed in the cytoplasmic and nuclear fractions of cells. Cells expressing high levels of Nm23-H1 exhibited increased KSR1 degradation in the presence of either cycloheximide or an Hsp90-directed drug currently in clinical trial, 17-allylamino-17-demethoxygeldanamycin (17-AAG). In agreement with KSR1 degradation data, high-Nm23-H1-expression cells were preferentially inhibited in anchorage-independent colonization assays by 17-AAG. KSR1 scaffold binding patterns are dynamic in both the cytoplasmic and nuclear compartments, modulated by metastasis suppressor expression. Metastasis suppressor expression levels can impact traditional signaling pathways, such as the Erk pathway, resulting in altered tumor cell sensitivity to cancer therapeutics.

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.

Expression and localization of nm23-H1 in the human placenta.

The involvement of the nm23 gene, initially documented as a putative metastasis-suppressor gene, in normal development and differentiation has been supported by several investigations. To date, however, localization and expression pattern of nm23 in the human placenta has not been determined. In the present study, the expression of nm23-H1 was examined by Northern blot and immunohistochemical analyses in human placentas from various stages of gestation. In first trimester placenta, the villous cytotrophoblast and the extravillous trophoblast exhibited strong cytoplasmic staining for nm23-H1. In second trimester and term placentas, the few cytotrophoblasts present showed less intense staining than those in first trimester placenta. Northern blot analysis demonstrated a progressive decrease in nm23-H1 gene expression with advancing gestational age, which is consistent with the results obtained by immunohistochemistry. These findings suggest that nm23-H1 is involved in the differentiation process of the trophoblast, and high levels of nm23-H1 expression seem to reflect the proliferating, less differentiated state of that reserve.

Nm23-H1: Genetic Alterations and Expression Patterns in Tumor Metastasis

Nm23-H1 originally was discovered on the basis of its reduced RNA expression in very highly metastatic murine melanoma cell lines. Since that time, it has been shown to reduce the metastatic potential of highly aggressive tumors and to be an indicator of poor patient prognosis in many cancer types. Although LOH of NME1 is prevalent in many tumors, this event does not predict reliably the overall levels of Nm23-H1 expression and therefore cannot be used as a genetic screen for the aggressive potential of a cancer. In addition, mutant forms of the gene exist; however, expression patterns seem to be the key to the differences observed between tumor cells of high and low metastatic potential. Differential Nm23-H1 expression may reflect transcriptional regulation and/or the stability of the Nm23-H1 transcript. The mechanism of action of the protein is still unknown; however, the protein does possess a unique kinase activity that is essential in other organisms. The histidine protein-kinase activity is the sole known activity that correlates tightly with the ability of Nm23-H1 to suppress cell motility. The identification of other components comprising this signaling pathway will be the next step toward unraveling the mysteries of this metastasis suppressor.

Evaluation by Multivariate Analysis of the Differentiation Inhibitory Factor nm23 as a Prognostic Factor in Acute Myelogenous Leukemia and Application to Other Hematologic Malignancies

AbstractThe differentiation inhibitory factor nm23 can inhibit the differentiation of murine and human myeloid leukemia cells. We recently reported that nm23 genes were overexpressed in acute myelogenous leukemia (AML), and a higher level of nm23-H1expression was correlated with a poor prognosis in AML, especially in AML-M5 (acute monocytic leukemia). To evaluate the importance ofnm23expression as a prognostic factor in AML, we compared it with other putative prognostic factors in AML. An analysis of the correlation between nm23 expression and the clinical parameters of 110 patients with AML demonstrated that increased nm23-H1mRNA levels were associated with resistance to initial chemotherapy and with reduced overall survival. Multivariate analysis using Cox's proportional hazard model also showed that elevated nm23-H1mRNA levels significantly contributed to the prognosis of patients with AML. Especially in AML-M5, nm23-H1 status was the most important prognostic factor. Furthermore, to determine whether we can apply the results observed in AML to other hematologic malignancies, we investigated the relative levels ofnm23-H1andnm23-H2transcripts in 149 patients with hematologic neoplasms, including 110 with de novo AML, 9 with de novo acute lymphoblastic leukemia, 14 with myelodysplastic syndrome, 16 with chronic myelogenous leukemia (CML), and 5 normal subjects by the reverse transcriptase-polymerase chain reaction. Expression of nm23-H1 was significantly higher in all the hematologic neoplasms, except CML in chronic phase, than in normal blood cells. nm23may have a prognostic effect in these hematologic malignancies as well as in AML.

Evaluation by Multivariate Analysis of the Differentiation Inhibitory Factor nm23 as a Prognostic Factor in Acute Myelogenous Leukemia and Application to Other Hematologic Malignancies

The differentiation inhibitory factor nm23 can inhibit the differentiation of murine and human myeloid leukemia cells. We recently reported that nm23 genes were overexpressed in acute myelogenous leukemia (AML), and a higher level of nm23-H1expression was correlated with a poor prognosis in AML, especially in AML-M5 (acute monocytic leukemia). To evaluate the importance ofnm23 expression as a prognostic factor in AML, we compared it with other putative prognostic factors in AML. An analysis of the correlation between nm23 expression and the clinical parameters of 110 patients with AML demonstrated that increased nm23-H1mRNA levels were associated with resistance to initial chemotherapy and with reduced overall survival. Multivariate analysis using Cox's proportional hazard model also showed that elevated nm23-H1mRNA levels significantly contributed to the prognosis of patients with AML. Especially in AML-M5, nm23-H1 status was the most important prognostic factor. Furthermore, to determine whether we can apply the results observed in AML to other hematologic malignancies, we investigated the relative levels of nm23-H1 and nm23-H2transcripts in 149 patients with hematologic neoplasms, including 110 with de novo AML, 9 with de novo acute lymphoblastic leukemia, 14 with myelodysplastic syndrome, 16 with chronic myelogenous leukemia (CML), and 5 normal subjects by the reverse transcriptase-polymerase chain reaction. Expression of nm23-H1 was significantly higher in all the hematologic neoplasms, except CML in chronic phase, than in normal blood cells. nm23 may have a prognostic effect in these hematologic malignancies as well as in AML.

Nm23--relationship to the metastatic potential of breast carcinoma cell lines, primary human xenografts, and lymph node negative breast carcinoma patients.

Since the discovery of nm23 (nonmetastatic) by Steeg et al. in 1988, a number of tumor cohort studies have shown an inverse relationship between the levels of expression of the nm23-H1 protein and disease aggressiveness and tumor metastatic potential. The relationship between the expression of nm23 protein and the metastatic potential of human breast carcinoma was analyzed in cell lines, xenografts, and in a retrospective lymph node negative breast carcinoma population. The lymph node negative breast carcinoma study was comprised of 40 patients: 19 with nonrecurrent and 21 with recurrent disease. The 40 patients were matched according to age, cathepsin D, tumor size, percent S-phase, DNA ploidy, steroid receptor status, and tumor grade. Nm23-H1 protein levels in cell lines and xenografts were analyzed quantitatively using Western blot analyses and semiquantitatively in tissue sections using immunocytochemistry. Immunocytochemical analysis of lymph node negative breast tumors was graded as the percent of tumor staining positive for nm23 and the intensity of staining. The metastatic potentials of the cell lines and xenografts were assessed as the ability to form metastatic lesions in nude mice. In the lymph node negative breast carcinoma patients, the metastatic potential was characterized as the incidence of breast carcinoma recurrence. The MCF-7 cell line expressed four- and tenfold higher levels of nm23-H1 than the highly metastatic MDA-MB-435 and MDA-MB-231 cells, respectively. Among the xenografts and cell lines, there was an inverse correlation between nm23-H1 expression and metastatic potential in athymic nude mice (correlation coefficient [R] = -0.51). The differences between the levels of nm23-H1 among the metastatic and nonmetastatic cell lines and xenografts were not statistically significant. Statistical analyses indicated that neither the intensity nor the percent of tumor staining positive for nm23 expression was correlated to the recurrence of breast carcinoma in the lymph node negative patient population that had been matched for other clinical prognostic markers. There was an inverse correlation (R = 0.51) between the levels of nm23-H1 expression in cell lines and xenografts and the metastatic potential in nude mice. In the retrospective lymph node negative breast carcinoma population, no clear association was demonstrated between the expression of nm23 and breast carcinoma recurrence. This observation suggests the nm23 expression does not predict outcome in lymph node negative breast carcinoma patients.

Immunohistochemical analysis of the nm23 gene product (NDP kinase) expression in astrocytic neoplasms.

The expression levels of nm23-H1 have been reported to correlate with the metastatic potential of some tumours. We have treated a child with a rare case of astrocytoma with diffuse osteoblastic metastases. We therefore decided to examine the expression of the nm23 gene product in 24 gliomas in order to clarify the association of its expression with the clinical features of the disease. A polyclonal antibody against a GST/nm23-H1 fusion protein was raised in rabbits. Twenty-four specimens, including 5 recurrent gliomas and one extraneural metastasis, were obtained from 19 patients treated surgically between 1990 and 1993 in our hospital. Immunohistochemical staining was performed on paraffin sections using an avidin-biotinyl peroxidase complex method. Of the 24 astrocytic neoplasms, 3 (12.5%) specimens from one patient with diffuse bony metastases stained intensely with nm23-H1. Two specimens obtained from glioblastoma multiforme patients stained weakly. The other 19 specimens were negative for nm23-H1 expression. Little or no nm23 expression was observed in adjacent nontumourous cerebral tissues. The results suggest that high levels of nm23 expression might correlate with extraneural metastatic potential in astrocytic neoplasms.

Expression and mutational analysis of Nm23-H1 in liver metastases of colorectal cancer.

It has been proposed that nm23-H1, a candidate suppressor gene for metastasis, plays an important role in metastasis formation of human tumours. In order to investigate its role in the progression of colorectal cancer, we analysed 22 liver metastases of this malignancy with respect to mutational changes, loss of heterozygosity and expression levels of nm23-H1. Although genetic alterations in nm23-H1 have recently been described in those colorectal adenocarcinomas which give rise to distant metastases, we were unable to detect any mutation in the coding sequence of nm23-H1 in the metastatic tissue itself. We further analysed the metastases with respect to allelic deletions at the chromosomal locus of nm23. However, no loss of heterozygosity could be detected in ten informative cases. Moreover, the mRNA expression levels of nm23-H1 in the metastatic tissues were not significantly different from those in normal colon mucosa. Thus, although nm23-H1 might be involved in metastasis suppression of certain tumour types, in colorectal tumour progression its role remains to be determined.

Evaluation of the expression levels of nm23-h1 mRNA in primary breast cancer, benign breast disease, axillary lymph nodes and normal breast tissue

Expression levels of nm23-H1 were evaluated in a variety of normal benign and malignant breast tissues by Northern and slot blot. Tissues from 153 patients presenting with palpable breast lesions were studied: 132 primary infiltrating breast cancers, 9 pure duct carcinoma in situ lesions, a phyllodes tumor, 9 benign lesions and 2 local recurrences of carcinoma. In addition to lesional tissue, 49 samples of macroscopically normal breast tissue, 37 axillary lymph nodes and 9 samples from patients undergoing cosmetic reduction mammoplasty were studied. Sets of normal breast tissue, primary tumor and lymph node tissue from individual patients were available for comparison in 37 cases. A wide range of gene expression was detected in the various tissue types. The highest levels of expression were detected in malignant samples with in situ carcinomas being associated with the highest levels of gene expression. The expression levels of nm23-H1 in normal breast tissue were lower than the corresponding tumors from the same patients (p < 0.0005). Benign breast lesions (including 6 fibroadenomas) had levels of gene expression approximating those of the normal tissue samples. Normal axillary lymph nodes had significantly lower levels of nm23-H1 expression than nodes with metastatic deposits (p < 0.03). No significant association was observed between nm23-H1 expression levels and axillary node status in patients with infiltrating carcinoma, although there was a slight trend toward lower nm23-H1 mRNA levels in the node negative group.(ABSTRACT TRUNCATED AT 250 WORDS)

Nm23-H1 metastasis suppressor gene expression in primary breast cancer: associations with axillary lymph node status, tumour size, type and grade

The nm23-H1 gene has tumour suppressor functions and is a putative metastasis suppressor. Higher levels of expression of the gene in breast carcinoma have been associated with the absence of lymph node metastasis, and with longer relapse free intervals and overall survival.Expression levels of nm23-H1 in breast carcinoma were examined by Northern and slot blot in a consecutive series of 105 patients. The levels of nm23-H1 mRNA expression were examined for associations with axillary lymph node metastasis, and with tumour size, tumour type and grade, mitotic rate, nuclear size and pleomorphism and vascular invastion, in 97 cases of invasive cancer. No statistically significant differences in nm23 expression levels between axillary node negative and axillary node positive infiltrating duct carcinomas were observed. There was no correlation between nm23-H1 expression levels and other histopathologically determined prognostic factors. Higher levels of gene expression were demonstrated in pure ductal carcinoma in situ (DCIS) lesions when compared to invasive tumours; further analysis suggested that DCIS components within invasive tumours contributed to measurements of nm23 expression, possibly masking the lower expression levels of the invasive component in some cases. Further correlative studies, using in situ hybridization or gene product immunohistochemistry would be most suited to determining the contribution of different tissue components in breast cancer.