The expression and clinical significance of metastasis suppressor gene and matrix metalloproteinase-2 in esophageal squamous cell of carcinoma.

To investigate the expression and clinical significance of metastasis suppressor gene and matrix metalloproteinase-2 in esophageal squamous cell of carcinoma. choose 30 cases of specimens of esophageal squamous cell carcinoma which are removed in surgery and confirmed by pathology and 30 cases of specimens of normal esophageal mucosa. Use immunohistochemistry SP method to detect the expression of nm23-H1, MMP-2 protein in esophageal squamous cell carcinoma and normal esophageal mucosal. The positive rate of nm23-H1 protein in esophageal squamous cell carcinoma was 43.3% (13/30), while that in normal esophageal mucosa was 100% (30/30), which has a significant difference between them (χ2=22. 083, P<0.05). The positive rate of MMP-2 protein in esophageal squamous cell carcinoma was 90.0% (27/30), while that in normal esophageal mucosa was 33.3% (10/30), and there is a significant difference between them (χ2=28. 370, P<0.05); For the expression of nm23-H1 and MMP-2 in esophageal squamous cell carcinoma, there was nothing to do with sex, age and tumor size (P>0.05), but it was related to the degree of tumor differentiation, depth of invasion and lymph node metastasis (P<0.05); The expression of nm23-H1 is related to the cut end of residual cancer (P<0.05), while the expression of MMP-2 has nothing to do with the cut end of residual cancer (P>0.05); The expression of nm23-H1 and MMP-2 in esophageal squamous cell carcinoma was negatively correlated. nm23-H1 and MMP-2 have played a role in the development of esophageal cancer, which can promote the occurence of distant metastasis; The loss of expression of nm23-H1 may be related to cut end residual cancer; nm23-H1 and MMP-2 may be as an indicator for esophageal cancer metastasis and prognosis.

A splicing variant of NME1 negatively regulates NF-κB signaling and inhibits cancer metastasis by interacting with IKKß.

IKKß functions as a principal upstream activator of the canonical NF-κB pathway by phosphorylating IκB, leading to its proteasomal degradation. Because IKKß is considered a therapeutic target, understanding its regulation may facilitate the design of efficient regulators of this molecule. Here, we report a novel IKKß-interacting molecule, NME1L, a splicing variant of the NME1 protein. NME1 has attracted attention in cancer research because of its antimetastatic activity and reduced expression in multiple aggressive types of cancer. However, the effect was just moderate but not dramatic in anti-cancer activities. We found that only NME1L interacts with IKKß. Exogenous expression of NME1L resulted in a potent decrease in TNFα-stimulated NF-κB activation, whereas knockdown of NME1/NME1L with shRNA enhanced activity of NF-κB. NME1L down-regulates IKKß signaling by blocking IKKß-mediated IκB degradation. When NME1L was introduced into highly metastatic HT1080 cells, the mobility was efficiently inhibited. Furthermore, in a metastasis assay, NME1L-expressing cells did not colonize the lung. Based on these results, NME1L is a potent antimetastatic protein and may be a useful weapon in the fight against cancers.

Upregulation of KCa3.1 K(+) channel in mesenteric lymph node CD4(+) T lymphocytes from a mouse model of dextran sodium sulfate-induced inflammatory bowel disease.

The intermediate-conductance Ca(2+)-activated K(+) channel KCa3.1/KCNN4 plays an important role in the modulation of Ca(2+) signaling through the control of the membrane potential in T lymphocytes. Here, we study the involvement of KCa3.1 in the enlargement of the mesenteric lymph nodes (MLNs) in a mouse model of inflammatory bowel disease (IBD). The mouse model of IBD was prepared by exposing male C57BL/6J mice to 5% dextran sulfate sodium for 7 days. Inflammation-induced changes in KCa3.1 activity and the expressions of KCa3.1 and its regulators in MLN CD4(+) T lymphocytes were monitored by real-time PCR, Western blot, voltage-sensitive dye imaging, patch-clamp, and flow cytometric analyses. Concomitant with an upregulation of KCa3.1a and nucleoside diphosphate kinase B (NDPK-B), a positive KCa3.1 regulator, an increase in KCa3.1 activity was observed in MLN CD4(+) T lymphocytes in the IBD model. Pharmacological blockade of KCa3.1 elicited the following results: 1) a significant decrease in IBD disease severity, as assessed by diarrhea, visible fecal blood, inflammation, and crypt damage of the colon and MLN enlargement compared with control mice, and 2) the restoration of the expression levels of KCa3.1a, NDPK-B, and Th1 cytokines in IBD model MLN CD4(+) T lymphocytes. These findings suggest that the increase in KCa3.1 activity induced by the upregulation of KCa3.1a and NDPK-B may be involved in the pathogenesis of IBD by mediating the enhancement of the proliferative response in MLN CD4(+) T lymphocyte and, therefore, that the pharmacological blockade of KCa3.1 may decrease the risk of IBD.

Regulation of Nm23-H1 and cell invasiveness by Kaposi's sarcoma-associated herpesvirus.

The Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS), and the induction of an invasive cellular phenotype by KSHV following de novo infection is an important pathogenic component mediating tumor progression. The metastasis suppressor gene known as Nm23-H1 regulates tumor cell invasiveness, but whether KSHV itself regulates Nm23-H1 expression or subcellular localization, and whether this impacts cell invasiveness, has not been established. We found that KSHV increases expression and nuclear translocation of Nm23-H1 and that nuclear translocation of Nm23-H1 is regulated by the KSHV-encoded latency-associated nuclear antigen (LANA). Moreover, activation of the Ras-BRaf-MAPK (mitogen-activated protein kinase) signal transduction pathway, secretion of promigratory factors associated with this pathway, and cell invasiveness are dependent on KSHV regulation of Nm23-H1. Finally, induction of cytoplasmic overexpression of Nm23-H1 using a pharmacologic inhibitor of DNA methylation reduced KSHV-associated Ras-BRaf-MAPK pathway activation and suppressed KSHV-induced invasiveness. These data provide the first evidence for KSHV regulation of Nm23-H1 as a mechanism for KSHV induction of an invasive cellular phenotype and support the potential utility of targeting Nm23-H1 as a therapeutic approach for the treatment of KS.

Diva/BclB regulates differentiation by inhibiting NDPKB/Nm23H2-mediated neuronal differentiation in PC-12 cells.

BACKGROUND: Diva (death inducer binding to vBcl-2 and Apaf-1)/BclB is a Bcl-2 family member, which is known for its function in apoptosis. Diva/BclB has been shown to interact with NDPKB/Nm23H2, which is involved in cellular differentiation. Thus far, there has been no direct evidence of Diva/BclB having a role in differentiation. In the present study, we investigated the expression of Diva/BclB and NDPKB/Nm23H2 during differentiation in PC-12 cell line. RESULTS: Our results show that after differentiation, Diva/BclB expression was decreased and reciprocally, NDPKB/Nm23H2 expression was increased and it translocated into the nucleus. Overexpression of NDPKB/Nm23H2 promoted PC-12 neuronal differentiation by increasing neurite outgrowth and arresting cell cycle progression. There was a concurrent downregulation of Diva/Boo when NDPKB/Nm23H2 was overexpressed, which mirrors the effect of NGF on PC-12 cell differentiation. Overexpression of Diva/BclB did not change the expression level of NDPKB/Nm23H2, but inhibited its nuclear localization. Cells that overexpressed Diva/BclB presented a decreased percentage of differentiated cells and average neurite length was shortened. This was due to an increase in the formation of Diva/BclB and NDPKB/Nm23H2 complexes as well as Diva/BclB and ß-tubulin complexes. Concomitantly, there was a decrease in formation of NDPKB/Nm23H2 and ß-tubulin complexes. Overexpression of Diva/BclB also resulted in a higher percentage of S-phase cells. CONCLUSION: Our results showed a novel role for Diva/BclB in neuronal differentiation. Its downregulation during neuronal differentiation may be necessary to allow NDPKB/Nm23H2 and ß-tubulin interaction that promotes NDPKB/Nm23H2 mediated differentiation.

Prognostic impact of nm23-H1 and PCNA expression in pathologic stage I non-small cell lung cancer.

INTRODUCTION: The purpose of this study was to evaluate the value of nm23-H1 and proliferating cell nuclear antigen (PCNA) expression as well as other confirmed prognostic factors in predicting the clinical outcome after definitive surgery of pathologic stage I non-small cell lung cancer (NSCLC). METHODS: Four hundred fifty-two consecutive and non-selected patients who underwent definitive surgery for stage I NSCLC were included in this study. Formalin-fixed paraffin-embedded specimens were stained for nm23-H1 and PCNA, the correlation between the staining and its clinicopathological parameters, and its prognostic power were analyzed statistically. RESULTS: Of the 452 patients studied, 320 cases (70.8%) were high expression for nm23-H1. A total of 182 carcinomas (40.3%) were PCNA high expression tumors. PCNA expression correlated with serum CEA level (P < 0.001), and differentiation (P < 0.001). In univariate analysis by log-rank test, serum CEA level, pT stage, differentiation, nm23-H1 expression, and PCNA expression were significant prognostic factors (P = 0.037, 0.021, <0.001, 0.042, and 0.014, respectively). In multivariate analysis, pT stage and nm23-H1 expression maintained its independent prognostic influence on overall survival (P = 0.041 and 0.003, respectively). CONCLUSIONS: nm23-H1 may be a good biomarker to be applied in clinic to predict the prognosis of patients with completely resected pathologic stage I NSCLC.

Expressions of nucleoside diphosphate kinase (nm23) in tumor tissues are related with metastasis and length of survival of patients with hepatocellular carcinoma.

OBJECTIVE: To evaluate the relationship of expressions of nucleoside diphosphate kinase (nm23) and proliferating cell nuclear antigen (PCNA), as well as apoptosis, with the prognosis of HCC patients by analyzing their pathological and clinical data. METHODS: The expressions of nm23 and PCNA were analyzed by immunohistochemistry and the apoptotic phenomena were detected by TUNEL technique in the liver samples from 43 HCC tissues, 39 para-neoplastic tissues, and 10 normal tissues. The mean apoptosis index (AI) and proliferative index (PI) in individual sample were calculated. RESULTS: As shown by the detection, 32.6% of carcinomas had negative nm23 signal in tumor tissues, whereas all para-neoplastic and normal tissues had positive nm23. The AI in nm23 positive HCC was significantly higher than that in nm23 negative one, with statistical difference (P<0.05). Furthermore, the expressions of nm23, and the values of AI and PI were contrastively analyzed with some main pathological and clinical data of HCC. It revealed that HCC with extrahepatic metastasis showed remarkable correlation with the negative nm23 (P=0.013) and higher PI values of HCC (P=0.015). The disease-free survival in HCC patients with negative nm23 expression was significantly poorer than that in patients with positive nm23 expression. CONCLUSIONS: These data suggest that expressions of nm23 protein in tumor tissues are correlated with occurrences of metastasis and length of survival of the HCC patients, which may be an indicator for their prognosis.

Clinical significance of altered nm23-H1, EGFR, RB and p53 expression in bilharzial bladder cancer.

BACKGROUND: Clinical characterization of bladder carcinomas is still inadequate using the standard clinico-pathological prognostic markers. We assessed the correlation between nm23-H1, Rb, EGFR and p53 in relation to the clinical outcome of patients with muscle invasive bilharzial bladder cancer (MI-BBC). METHODS: nm23-H1, Rb, EGFR and p53 expression was assessed in 59 MI-BBC patients using immunohistochemistry and reverse transcription (RT-PCR) and was correlated to the standard clinico-pathological prognostic factors, patient's outcome and the overall survival (OS) rate. RESULTS: Overexpression of EGFR and p53 proteins was detected in 66.1% and 35.6%; respectively. Loss of nm23-H1and Rb proteins was detected in 42.4% and 57.6%; respectively. Increased EGFR and loss of nm23-H1 RNA were detected in 61.5% and 36.5%; respectively. There was a statistically significant correlation between p53 and EGFR overexpression (p < 0.0001), nm23 loss (protein and RNA), lymph node status (p < 0.0001); between the incidence of local recurrence and EGFR RNA overexpression (p= 0.003) as well as between the incidence of metastasis and altered Rb expression (p = 0.026), p53 overexpression (p < 0.0001) and mutation (p = 0.04). Advanced disease stage correlated significantly with increased EGFR (protein and RNA) (p = 0.003 & 0.01), reduced nm23-H1 RNA (p = 0.02), altered Rb (p = 0.023), and p53 overexpression (p = 0.004). OS rates correlated significantly, in univariate analysis, with p53 overexpression (p = 0.011), increased EGFR (protein and RNA, p = 0.034&0.031), nm23-H1 RNA loss (p = 0.021) and aberrations of > or = 2 genes. However, multivariate analysis showed that only high EGFR overexpression, metastatic recurrence, high tumor grade and the combination of > or = 2 affected markers were independent prognostic factors. CONCLUSION: nm23-H1, EGFR and p53 could be used as prognostic biomarkers in MI-BBC patients. In addition to the standard pathological prognostic factors, a combination of these markers (> or = 2) has synergistic effects in stratifying patients into variable risk groups. The higher is the number of altered biomarkers, the higher will be the risk of disease progression and death.

CD44v6, MMP-7 and nuclear Cdx2 are significant biomarkers for prediction of lymph node metastasis in primary gastric cancer.

The aim of this study was to examine the expression of CD44v6, CD54, Cdx2, CXCL5, Cyclin B1, MMP-7, nm23, RCAS1 and Survivin in primary gastric cancer and to investigate whether these molecules were useful in predicting the lymph node status. They were selected as candidates for indicators of lymph node metastasis from various kinds of cancer-associated genes reported previously. In 135 cases of radically resected primary gastric adenocarcinoma, we investigated the association between the expression of these molecules and clinocopathologic factors by immunohistochemistry. The results revealed that the expression of CD44v6 and MMP-7 were significantly associated with lymph node status. By contrast, nuclear Cdx2 expression was found to be inversely correlated with lymph node metastasis. Moreover, multivariate analysis demonstrated that CD44v6, MMP-7 and nuclear Cdx2 were independent predictors for lymph node status. In conclusion, our results suggest that positive expression of both CD44v6 and MMP-7, and negative expression of nuclear Cdx2 may serve as powerful predictors of lymph node metastasis in gastric cancer. Combined evaluation of these markers could be further useful to predict lymph node status clinically.

Effect of verapamil on the expression of EGFR and NM23 in A549 human lung cancer cells.

Despite the advances in the detection and treatment of lung cancer, the overall 5-year survival is only 10-20%. Accumulating evidence suggests that verapamil, a calcium channel antagonist, is a potential anticancer agent. Epidermal growth factor receptor (EGFR) is a key therapeutic target in many types of cancer, whereas nm23 is a putative metastasis suppressor gene. In this study, the effect of verapamil on the expression of nm23 and EGFR in A549 human lung cancer cells was investigated by quantitative real-time reverse transcription-polymerase reaction and immunohistochemical assays. The expression of EGFR and nm23 was also determined in lung cancer patients. Verapamil significantly reduced EGFR expression at both the mRNA and protein levels in A549 cells (p < 0.01). Verapamil also significantly increased the protein levels of nm23 in these cells (p < 0.01), although the mRNA levels of nm23 were not changed after verapamil treatment. Furthermore, the expression of EGFR in human lung cancer tissues was significantly higher than in normal lung tissues (p < 0.001). However, the expression of nm23 was not different between lung cancer and normal tissues. Our data suggest that verapamil may regulate the expression of EGFR and nw23 in lung cancer cells by transcriptional and post-transcriptional levels, respectively. EGFR may be a promising therapeutic molecular target for lung cancer treatment using verapamil and/or chemotherapeutic agents.

Genetic polymorphisms of metastasis suppressor gene NME1 and breast cancer survival.

PURPOSE: Ample evidence supports an important role of tumor metastasis suppressor genes in cancer metastatic processes. We evaluated the association of genetic polymorphisms of metastasis suppressor gene NME1 with breast cancer prognosis in a follow-up study of patients with primary breast cancer and further investigated the functions of these polymorphisms. EXPERIMENTAL DESIGN: NME1 genotypes were analyzed in a cohort of 1,134 breast cancer patients recruited as part of the Shanghai Breast Cancer Study who were followed for a median of 7.1 years. In vitro biochemical analyses were carried out to examine the function of NME1 gene polymorphisms. RESULTS: Single nucleotide polymorphisms (SNP) in the promoter region of the NME1 gene were found to be associated with breast cancer prognosis. Patients carrying the C allele in rs16949649 were associated with higher breast cancer-specific mortality [hazard ratio (HR), 1.4; 95% confidence interval (95% CI), 1.1-1.9] compared with those carrying the wild-type allele, and the association was more evident in patients with an early-stage cancer (HR, 1.7; 95% CI, 1.2-2.5). SNP rs2302254 was also associated with breast cancer prognosis, and the association was statistically significant for the risk of breast cancer relapse, metastasis, and death (HR, 1.3; 95% CI, 1.0-1.6). In vitro biochemical analyses showed that minor alleles in rs2302254 and rs3760468, which is in strong linkage disequilibrium with rs16949646, altered nuclear proteins binding capacity and reduced NME1 promoter activity, supporting the results from an association study of these SNPs with breast cancer survival. CONCLUSION: Promoter polymorphisms in the NME1 gene may alter its expression and influence breast cancer survival.

Immunohistochemical analysis of nm23 protein expression in thyroid papillary carcinoma and follicular neoplasm.

INTRODUCTION: We aimed at assessing the significance of nm23 gene expression in papillary and follicular carcinomas, the two most common differentiated thyroid carcinomas. MATERIALS AND METHODS: During a cross-sectional study, 173 paraffin blocks, including 131 papillary thyroid carcinomas, 12 follicular carcinomas and 30 follicular adenomas were stained with nm23 marker by immunohistochemistry method. Cytoplasmic staining in more than 10% of the tumor cells was considered as positive, and alpha<0.05 was established as the level of statistical significance for the evaluation of the correlation between nm23 expression and age, sex, tumor size, vascular /capsular invasion and lymph node involvement. RESULTS: nm23 was positive in 40% of the follicular adenoma, 67.2% of the papillary carcinoma and 66.7% of the follicular carcinoma. p value was more than 0.05 in the assessment of the relationship between nm23 and all of the above-mentioned parameters in differentiated thyroid carcinomas. nm23 expression did not significantly differentiate between follicular adenoma and carcinoma. CONCLUSION: According to our results, there is no relationship between nm23 immunoreactivity and age or sex of the patients. Also, nm23 cannot be considered as a useful marker for the evaluation of invasion in differentiated thyroid carcinomas or in distinctions between follicular adenoma and carcinoma.

Nm23-H1 expression of metastatic tumors in the lymph nodes is a prognostic indicator of oral squamous cell carcinoma.

We recently reported that low Nm23-H1 expression of primary oral squamous cell carcinoma (OSCC) was correlated with the occurrence of lymphatic metastasis. However, little is known about whether Nm23-H1 level of metastatic tumors in the cervical lymph nodes is reduced in comparison with primary oral cancers and its significance for patients' prognosis. By immunohistochemistry, we analyzed the Nm23-H1 expression in 52 pairs of OSCC specimens from primary oral cancers and their metastatic lymph nodes. Western blot analysis further confirmed the immunohistochemical interpretation. To verify the effects of Nm23-H1 on cell migration and invasion, we established several stable clones derived from a human OSCC cell line (SAS) by knockdown and overexpression. Wound-healing closure, transwell migration and invasion assays were performed to determine cell motility, migratory and invasive activities. Western blot analysis was carried out to evaluate cyclin A expression of OSCC cells with the altered Nm23-H1 levels following knockdown and overexpression. By immunohistochemistry, Nm23-H1 expression of metastatic lymph nodes was significantly lower than that of their primary oral cancers, supporting a role of Nm23-H1 in metastasis suppression. Negative Nm23-H1 interpretation of OSCC specimens, in either primary oral cancers or metastatic lymph nodes, indicated a poor survival outcome of patients. On the basis of in vitro studies of Nm23-H1 knockdown and overexpression, we demonstrated an inverse correlation between Nm23-H1 expression and the invasiveness of OSCC cells. Moreover, we observed the concomitant reduction in Nm23-H1 and cyclin A levels of metastatic tumors in both results of in vitro OSCC cells and ex vivo tumor specimens.

A clinicopathological study of nm23-H1 expression in classical Hodgkin's lymphoma.

BACKGROUND: We carried out immunohistochemistry to examine the expression of nm23-H1 in Hodgkin and Reed-Sternberg cells in patients with classical Hodgkin's lymphoma (CHL). PATIENTS AND METHODS: We evaluated 128 patients with CHL [87 patients with nodular sclerosis (NS) and 41 patients with mixed cellularity (MC)] for CD15, CD20, Ki-67, EBER, TIA-1, and nm23-H1 by immunohistochemistry. RESULTS: CD15 was expressed in 79%, CD20 in 11%, Ki-67 in 93%, EBER in 34%, TIA-1 in 11%, and nm23-H1 in 60% of the CHL patients. NS patients showed a significantly higher rate of nm23-H1 expression than MC patients (P < 0.001). The serum nm23-H1 level was significantly higher in patients with positive nm23 expression. Univariate analysis showed that stage IV, poor performance status, low hemoglobin level, low serum albumin level, age of 45 years or older, TIA-1-positive status, and nm23-H1-positive status were associated with significantly shorter progression-free survival. Multivariate analysis with these factors showed TIA-1 and cytoplasmic nm23-H1 expression to be significant and independent prognostic factors. CONCLUSIONS: Our results indicate that nm23-H1 expression is a prognostic factor for CHL and that it is as important as serum nm23-H1, both of which are useful for planning the treatment strategy.

Biophytum sensitivum (L.) DC inhibits tumor cell invasion and metastasis through a mechanism involving regulation of MMPs, prolyl hydroxylase, lysyl oxidase, nm23, ERK-1, ERK-2, STAT-1, and proinflammatory cytokine gene expression in metastatic lung tissue.

Biophytum sensitivum is a traditional oriental herbal medicine that is known for its immunostimulatory and antitumor effects. Tumor metastasis is the most important cause of cancer death. Although B sensitivum was shown to inhibit metastasis, the mechanism underlying this action is not well understood. In the present report, the authors had studied the effect of B sensitivum on the invasion and motility of B16F-10 melanoma cells and investigate the regulatory effect on the expression of matrix metalloproteases (MMPs), prolyl hydoxylase, lysyl oxidase, nm23, extracellular signal-regulated kinase (ERK)-1, ERK-2, signal transducer and activator of transcription (STAT)-1, and proinflammatory cytokines in metastatic tumor-bearing lungs. B sensitivum inhibited the invasion and motility of B16F-10 cells in a dose-dependent manner. B sensitivum inhibited the expression of MMP-2 and MMP-9, whereas it activated STAT-1 expression in metastatic tumor-bearing lungs. Similarly, inhibition of prolyl hydroxylase, lysyl oxidase, ERK-1, ERK-2, and vascular endothelial growth factor (VEGF) expression but activation of nm23 by B sensitivum was observed in metastatic tumor-bearing lungs. B sensitivum treatment also downregulated the expression of tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, and granulocyte monocyte-colony stimulating factor in metastatic tumor-bearing lungs. In B16F-10 cells, B sensitivum also inhibited the production of proinflammatory cytokines. Overall, the results indicate that B sensitivum exhibits antimetastatic effects through the inhibition of invasion and motility. The results also suggest that MMPs, prolyl hydroxylase, lysyl oxidase, nm23, ERKs, VEGF, STAT, and proinflammatory cytokines are critical regulators of the B sensitivum-mediated antimetastatic effect.

NM23 downregulation and lysophosphatidic acid receptor EDG2/lpa1 upregulation during myeloid differentiation of human leukemia cells.

The NM23 gene is overexpressed in many hematological malignancies and its overexpression predicts poor treatment outcomes. NM23 overexpression is thought to suppress myeloid differentiation of leukemia cells, but the molecular mechanism is unknown. In breast cancer cells, the lysophosphatidic acid (LPA) receptor EDG2/lpa1 was downregulated by NM23-H1 overexpression, and this reciprocal expression pattern was associated with suppressed or induced cell motility/metastasis. Here, we examined the relationship between EDG2 and NM23 expression during myeloid differentiation of leukemia cells. NM23 expression decreased and EDG2 expression increased during all-trans retinoic acid (ATRA)-induced myeloid differentiation of HL-60, NB4, and THP-1 leukemia cells. Moreover, this inverse correlation was more evident when myeloid differentiation was enhanced by ellagic acid, an inhibitor of NM23 activity. In contrast, there was no inverse correlation between EDG2 and NM23 expression during erythroid differentiation of HEL and K562 cells. ATRA plus LPA enhanced the motility of leukemia cells as well as breast cancer cells in an EDG2-dependent manner. These results suggest a common molecular mechanism between myeloid differentiation of leukemia cells and migration of breast cancer cells depending on NM23 and EDG2 expression levels.

Expression of nm23-H1 in uveal melanoma.

Uveal melanoma (UM) is the most common malignant intraocular tumor in adults. Despite the high accuracy of clinical diagnosis and advances in local treatment, more than 50% of UM patients develop metastasis within 10 years of initial diagnosis. NM23 is one of the human metastasis suppressor genes. Reduced nm23-H1 expression is correlated with high metastatic potential in many different cancers. The purpose of this study is to investigate the expression of nm23-H1 in UM and its potential value as a prognostic marker. Immunostaining of nm23-H1 was verified in five human UM cell lines with different metastatic potentials. The expression level of nm23-H1 mRNA was evaluated with one-step quantitative real-time PCR. The invasion ability of the cell lines was assessed before and after silencing nm23-H1 with small interference RNA. Thirty-two cases of paraffin-embedded specimens of human UM were immunostained with nm23-H1 monoclonal antibody. The immunostaining was evaluated in a semiquantitative fashion based on extent and intensity. The real-time PCR results of five human UM cell lines showed that expression of nm23-H1 was higher in cell lines with low metastatic potential compared with those with high metastatic potential (P<0.05). The invasive ability of the UM cell lines increased after silencing nm23-H1 expression with small interference RNA (P<0.05). The immunostaining of nm23-H1 was cytoplasmic in all cell lines and UM patients samples. The increased immunostaining intensity of nm23-H1 in patients' samples was associated with better survival rate (Kaplan-Meier test P=0.0097). The expression of nm23-H1 was not correlated with other prognostic factors. It can be concluded that nm23-H1 may be a prognostic marker to predict the survival rate of UM patients and it has the potential to identify high-risk patients.

Meta-Analysis of the Relationship between NM23 Expression to Gastric Cancer Risk and Clinical Features.

The prognostic value of reduced NM23 expression for gastric cancer (GC) patients is still contradictory. Thus, we conducted a meta-analysis to quantitatively evaluate the association of NM23 expression with GC risk and clinical features by analyzing 27 publications. The result of our meta-analysis indicated that NM23 expression is markedly reduced in gastric cancer tissues (OR = 3.15; 95% CI = 1.97-5.03; P < 0.001). Furthermore, NM23 expression was negatively correlated with N stage, TNM stage, and histological grade. However, NM23 expression was not correlated with T stage, lymphatic invasion, vascular invasion, and 5-year overall survival rate. In conclusion, reduced NM23 expression correlated with gastric cancer risk, but its association with GC clinical features remains inconclusive. Therefore, large-scale and well-designed studies, which use uniform antibody and criterion of NM23 positive expression, are required to further validate the role of the NM23 in predicting GC progression.

p18 inhibits reprogramming through inactivation of Cdk4/6.

Pluripotent stem cells (PSCs), including embryonic and induced pluripotent stem cells (iPSCs), show atypical cell cycle regulation characterized by a high proliferation rate and a shorter G1 phase compared with somatic cells. The mechanisms by which somatic cells remodel their cell cycle to achieve the high proliferation rate of PSCs during reprogramming are unclear. Here we identify that the Ink4 protein p18, which is expressed at high levels in somatic cells but at low levels in PSCs, is a roadblock to successful reprogramming. Mild inhibition of p18 expression enhances reprogramming efficiency, while ectopic expression of p18 completely blocks reprogramming. Mechanistic studies show that expression of wild-type p18, but not a p18(D68N) mutant which cannot inhibit Cdk4/6, down-regulates expression of Cdk4/6 target genes involved in DNA synthesis (TK, TS, DHFR, PCNA) and cell cycle regulation (CDK1 and CCNA2) and thus inhibits reprogramming. These results indicate that p18 blocks reprogramming by targeting Cdk4/6-mediated cell cycle regulation. Taken together, our results define a novel pathway that inhibits somatic cell reprogramming, and provide a new target to enhance reprogramming efficiency.

The association of nm23-H1 expression with a poor prognosis in patients with peripheral T-cell lymphoma, not otherwise specified.

nm23-H1 was originally identified as a protein that is expressed at a lower than usual level in metastatic cancer cells. The nm23 genes play critical roles in cellular proliferation, differentiation, oncogenesis, and tumor metastasis. Peripheral T-cell lymphoma (PTCL) is relatively rare, accounting for only 10% to 15% of non-Hodgkin's lymphomas. We examined whether nm23-H1 is a prognostic factor of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). PTCL is more aggressive and has a poorer prognosis than diffuse large B-cell lymphoma. nm23-H1 was positive in 44.1% of PTCL-NOS patients. nm23-H1 expression was not correlated with age, performance status (PS), lactate dehydrogenase (LDH) level, or stage. The nm23-H1-positive group had significantly shorter overall survival (OS). OS was significantly shorter in patients with the following clinicopathologic features: age ＞ 60 years, PS of 2-4, LDH ＞ normal, bone marrow involvement, or nm23-H1-positive lymphoma. The nm23-H1 protein may be an important prognostic factor in PTCL-NOS. Because our results suggest that nm23-HI is produced by lymphoma cells, we expect to see the development of new treatments targeting nm23 overexpression.