Risk factors for glioma in adults: a case-control study in northeast China

A case-control study of risk factors for glioma in adults was carried out in Heilongjiang province in northeast China. Between September 1989 and May 1995, 218 histologically confirmed cases of glioma requiring surgery for tumor removal (139 astrocytoma glioma and 79 other glioma) and 436 controls with non-neoplastic and non-neurological disease were recruited and personally interviewed in the wards of six major hospitals. Controls were matched by sex, age, and area of residence. Occupational, lifestyle, and medical information was obtained through a standardized questionnaire. Use of liquor was associated with cancer risk. Compared with males who never drank liquor, males with total lifetime liquor consumption of less than 1000 liters had an adjusted odds ratio (OR) of 1.60 (95% CI: 0.89-2.88) and for more than 1000 liters, 2.73 (95% CI: 1.06-7.08). Statistically significant associations were also found for diseases related to the brain (OR: 5.75; 95% CI: 1.08-30.47) and trauma to the head requiring medical attention (OR: 4.09; 95% CI: 2.51-10.31). Increased consumption of vegetables and of fruit were each associated with decreased glioma risk. Compared with lowest quartile intake, adjusted risks associated with highest quartile intake were 0.51 (95% CI: 0.29-0.89) for total vegetables and 0.28 (95% CI: 0.16-0.51) for total fruit.

B lymphocytes induce the formation of follicular dendritic cell clusters in a lymphotoxin alpha-dependent fashion

Lymphotoxin (LT)alpha is expressed by activated T cells, especially CD4(+) T helper type 1 cells, and by activated B and natural killer cells, but the functions of this molecule in vivo are incompletely defined. We have previously shown that follicular dendritic cell (FDC) clusters and germinal centers (GCs) are absent from the peripheral lymphoid tissues of LTalpha-deficient (LTalpha-/-) mice. LTalpha-/- mice produce high levels of antigen-specific immunoglobulin (Ig)M, but very low levels of IgG after immunization with sheep red blood cells. We show here that LTalpha-expressing B cells are essential for the recovery of primary, secondary, and memory humoral immune responses in LTalpha-/- mice. It is not necessary for T cells to express LTalpha to support these immune functions. Importantly, LTalpha-expressing B cells alone are essential and sufficient for the formation of FDC clusters. Once these clusters are formed by LTalpha-expressing B cells, then LTalpha-deficient T cells can interact with B cells to generate GCs and productive class-switched antibody responses. Thus, B cells themselves provide an essential signal that induces and maintains the lymphoid microenvironment essential for GC formation and class-switched Ig responses.

[Mechanism for the formation of F-V curve configuration analysed with tangent time constant and wave-speed theory in normal adolescents]

To understand the distribution of F-V curve configuration and the characteristics of tangent time constant (tau t), and to explore the mechanical mechanism for the formation of F-V curve configuration, we measured the tau t of high, mid, low lung volumes (tau t75, tau t50, tau t25) from F-V curves in 728 normal adolescents aged 8-19. The results showed that the distribution of the concave type was the highest among 4 types of F-V curve configuration with a range of 40%-70%. Its tau t features were tau t75 > tau t50 > tau t25 and magnitude of tau t75 > 1s. Then the concave type and its tau t features were called "adolescent fashion". Contrastedly, the distribution of the convex type was the lowest, only 4%-22%. The mechanical mechanism responsible for the formation of the concave type was analysed with the wave-speed theory. During the growth of adolescents, the lung elastic pressure and driving pressure increase with age. The diameters of airways increase, especially those of the peripheral airways with profuse branches. These changes lead to a decrease of resistance. Therefore, the critical flow (Vc) or wave-speed flow (Vmax) of peripheral airways is raised, and the flow there-in could hardly be limited. Thus the choke point (CP) will stay in trachea for a longer period, leading to the elongation of the plateau towards the tail or the concavity of the curve towards the volume axis and hence the formation of the concave type.

Negative regulation of granulocytic differentiation in the myeloid precursor cell line 32Dcl3 by ear-2, a mammalian homolog of Drosophila seven-up, and a chimeric leukemogenic gene, AML1/ETO

The polyomavirus enhancer binding protein 2alphaB (AML1/PEBP2alphaB/Cbfa2) plays a pivotal role in granulocyte colony-stimulating factor (G-CSF)-mediated differentiation of a myeloid progenitor cell line, 32Dc13. In this article, we report the identification of a PEBP2alphaB interacting protein, Ear-2, an orphan member of the nuclear hormone receptor superfamily that directly binds to and can inhibit the function of PEBP2alphaB. Ear-2 is expressed in proliferating 32Dc13 cells in presence of interleukin 3 but is down-regulated during differentiation induced by G-CSF. Interestingly, AML1/ETO(MTG8), a leukemogenic chimeric protein can block the differentiation of 32Dc13 cells, which is accompanied by the sustained expression of ear-2. Overexpression of Ear-2 can prevent G-CSF-induced differentiation, strongly suggesting that ear-2 is a key negative regulator of granulocytic differentiation. Our results indicate that a dynamic balance existing between PEBP2alphaB and Ear-2 appears to determine the choice between growth or differentiation for myeloid cells.

Effect of TGF-beta 1 on PDGF receptors expression in human scar fibroblasts

This study examined the effect of exogenous TGF -beta1 on platelet derived growth factor alpha and beta (PDGF-alpha, beta) receptor expression in human dermal fibroblasts derived from both normal cutaneous tissues (normal skin [NSk]) and (normal scar [NSc]) and abnormal scar (keloid). TGF-beta and PDGF are present in the early phases of wound healing and are implicated in tissue fibrosis. In this study, replicate samples of NSk, NSc and keloid fibroblasts were grown to subconfluency in DMEM/10% FBS followed by replacement of media with DMEM/0.1%FBS for 24 hrs. One group of cells (NSk, NSc and keloid) were exposed to 10 ng/mL of exogenous TGF-beta1 for 24 hours, while the other group was used as control with no exposure to exogenous TGF-beta1. RadioImmunoBinding assays, Western and Northern blot analysis were performed to examine both PDGF-alpha and PDGF-beta receptor expression at the transcriptional and post-transcriptional levels. cDNA receptor probes were synthesized using polymerase chain reaction (PCR) with selected primer sets derived from published sequences. Beta-actin probe was used as a control to confirm that the same quantity of RNA was used for each experimental condition. TGF-beta1 was found to upregulate the expression of PDGF-alpha receptor for keloid fibroblasts but not for NSk or NSc fibroblasts. No effect was observed for TGF-beta 1 on PDGF-beta receptor expression for any of the cell lines examined.

Temperature dependence of outer hair cell nonlinear capacitance

The temperature dependence of outer hair cell motility-related gating current and capacitance was evaluated under whole-cell voltage clamp. Temperature change caused a shift of these voltage-dependent functions along the voltage axis, with a decrease in temperature causing a negative shift in the voltage at peak capacitance (Vpkcm) of 19.2 mV per 10 degrees C. Gating current kinetics showed only mild temperature dependence, the Q10 being about 1.5. Temperature is speculated to affect outer hair cell (OHC) mechanical gain and frequency response by alterations in lateral membrane viscoelastic properties. Such temperature-dependent effects on the OHC may mediate known temperature effects on in vivo cochlear physiology.

[Pathogenetic study of femoral head necrosis caused by cortical steroid]

OBJECTIVE

To study cortical steroid caused femoral head necrosis.

METHODS

We designed an experimental animal model of femoral head necrosis through cortical steroid administration. Lipid analyses of blood samples were made and examined specimens from livers and femoral heads were studied with HE, TEM methods.

RESULTS

Cortical steroid resulted in dearrangement of fat metabolism, lipid change of liver and hyperlipemia.

CONCLUSION

The pathogenesis of femoral head necrosis is due to fatty degeneration of osteocytes.

Distinct roles of lymphotoxin alpha and the type I tumor necrosis factor (TNF) receptor in the establishment of follicular dendritic cells from non-bone marrow-derived cells

In mice deficient in either lymphotoxin alpha (LT-alpha) or type I tumor necrosis factor receptor (TNFR-I), organized clusters of follicular dendritic cells (FDC) and germinal centers (GC) are absent from the spleen. We investigated the role of LT-alpha and TNFR-I in the establishment of spleen FDC and GC structure by using reciprocal bone marrow (BM) transfer. When LT-alpha-deficient mice were reconstituted with wild-type BM, FDC organization and the ability to form GC were restored, indicating that the LT-alpha-expressing cells required to establish organized FDC are derived from BM. The role of LT-alpha in establishing organized FDC structure was further investigated by the transfer of complement receptor 1 and 2 (CR1/2)-deficient BM cells into LT-alpha-deficient mice. Organized FDC were identified with both the FDC-M1 and anti-CR1 monoclonal antibodies in these BM-chimeric mice, indicating that these cells were derived from the LT-alpha-deficient recipient. Thus, expression of LT-alpha in the BM-derived cells, but not in the non-BM-derived cells, is required for the maturation of FDC from non-BM precursor cells. In contrast, when TNFR-I-deficient mice were reconstituted with wild-type BM, they showed no detectable FDC clusters or GC formation. This indicates that TNFR-I expression on non-BM-derived cellular components is necessary for the establishment of these lymphoid structures. TNFR-I-deficient BM was able to restore FDC organization and GC formation in LT-alpha-deficient mice, indicating that formation of these structures does not require TNFR-I expression on BM-derived cells. The data in this study demonstrate that FDC organization and GC formation are controlled by both LT-alpha-expressing BM-derived cells and by TNFR-I-expressing non-BM-derived cells.

The Electronic Spectrum of Gaseous CoO in the Visible Region

Laser excitation spectra of gaseous CoO have been recorded using Doppler-limited intracavity spectroscopy and supersonic jet-cooled molecular beam methods. As seen in the molecular beam spectra there are nearly 100 bands arising from the X4Delta7/2 spin component of the ground state in the wavelength region 430-720 nm. All of them are very strongly red-degraded and most of them are perturbed. 59Co hyperfine broadenings or splittings have been observed in many. The bands can be arranged into five electronic transitions, together with a considerable number of "extra" bands induced by perturbations; two of the excited electronic states are 4Phi, while the other three, which lie within 1700 cm-1, are 4Delta. Semi-empirical calculations have been carried out for the 4Delta excited states, using exchange integrals transferred from the TiO and VO spectra; the predicted energies, spin-orbit structures, and relative intensities in absorption are consistent with the assignment of all three 4Delta states to the same electron configuration, (4ssigma)1(3ddelta)3(3dpi)2(3dsigma)1. It seems that there are extensive interactions between the excited 4Delta states, because only one of them gives rise to a recognizable, though irregular, long vibrational progression in absorption. The other two progressions die out abruptly and unexpectedly after three or four members, presumably as a result of interference effects; however, wavelength-resolved fluorescence studies, together with calculations of the Franck-Condon overlap integrals to the various vibrational levels of the ground state, show that the upper state progressions reappear following a region of confused absorption. All of the excited states show highly irregular variations of their vibrational intervals and rotational constants with the vibrational quantum number, v. The wavelength-resolved fluorescence spectra give evidence for new low-lying electronic states of CoO at 3038, 5989, and 9105 cm-1; based on its vibrational frequency the 3038 cm-1 state is possibly the sigmadelta4pi2 B4Sigma- state. Copyright 1997 Academic Press. Copyright 1997Academic Press

[Analysis of the mechanism on the formation of configuration of F-V curves with tangent time constant in adult humans]

The tangent time constants at high, mid, low lung volumes (tau t75, tau t50, tau t25) were measured from F-V curves of 258 normal adults aged 20-49. The configurations of F-V curves were classified into the plateau, linear, convex and concave types. In terms of distribution ratio, the convex type increased with age, but the concave type decreased with age. The top of F-V curve was chiefly determined by the length of magnitude of tau t75. The magnitude of tau t75 was the longest for the concave type; its top fell down slowly with the formation of a blant round shape. The magnitude of tau t75 of convex type was the shortest; its top fell down rapidly and formed a peak shape. The mid portion of the curve was determined by the length of tau t50 and the height of V50. The tau t50 was longer and V50 was higher in the plateau and concave types, so that the mid portion fell down slowly to form a plateau or to be concave to the volume axis. While tau t50 was shorter and V50 was lower in the convex and linear types, the mid portion became convex to the volume axis or formed a linear shape. The configuration of the tail was determined by tau t25 and V25. The long tau t25 and high V25 in the plateou type implied the extension of plateau to the low lung volumes. While tau t25 in theother 3 types was shorter. However, V25 was higher in the concave type, thus it made the tail fall down fast and become concave to the volume axis. The V25 was lower in the convex type with the tail convex to the volume axis. The height of V25 in the linear type was between the concave and convex ones with the tail falling in a linear fashion.

[The expression of tumor suppressor gene p53 and Rb gene in nasopharyngeal carcinoma]

In order to observe the relation of tumor supperssor gene p53 and Rb gene to nasopharyngeal carcinoma, we investigated p53 gene mutations in exon 7-8 in 33 cases of nasopharygeal carcinoma (NPC), using single-strand conformation ploymorphism analysis of PCR (PCR-SSCP). The data showed p53 mutations in 7 of 33 specimens at exon 8 (21.2%). No mutation in exon 7 was detected. Analysis of Rb gene in NPC tissues by southern blot revealed the deletion and loss of activity of Rb gene in 11 of 13 cases (86.6%). Our results suggest that Rb gene and p53 gene are closely associated with the tumorigenesis of NPC.

Developed, binary, image processing in a dual-channel, optical, real-time morphological processor

A developed, binary, image-processing technique is proposed, and a dual-channel, optical, real-time morphological processor is developed. Nine binary image processings can be realized fully in parallel. The measures for compensating scale and rotation distortion for pattern recognition are provided. Some applications of optical, morphological binary image processing are studied and experimental results are listed.

A novel transcript encoding an N-terminally truncated AML1/PEBP2 alphaB protein interferes with transactivation and blocks granulocytic differentiation of 32Dcl3 myeloid cells

The gene AML1/PEBP2 alphaB encodes the alpha subunit of transcription factor PEBP2/CBF and is essential for the establishment of fetal liver hematopoiesis. Rearrangements of AML1 are frequently associated with several types of human leukemia. Three types of AML1 cDNA isoforms have been described to date; they have been designated AML1a, AML1b, and AML1c. All of these isoforms encode the conserved-Runt domain, which harbors the DNA binding and heterodimerization activities. We have identified a new isoform of the AML1 transcript, termed AML1 deltaN, in which exon 1 is directly connected to exon 4 by alternative splicing. The AML1 deltaN transcript was detected in various hematopoietic cell lines of lymphoid to myeloid cell origin, as revealed by RNase protection and reverse transcriptase PCR analyses. The protein product of AML1 deltaN lacks the N-terminal region of AML1, including half of the Runt domain, and neither binds to DNA nor heterodimerizes with the beta subunit. However, AML1 deltaN was found to interfere with the transactivation activity of PEBP2, and the molecular region responsible for this activity was identified. Stable expression of AML1 deltaN in 32Dcl3 myeloid cells blocked granulocytic differentiation in response to granulocyte colony-stimulating factor. These results suggest that AML1 deltaN acts as a modulator of AML1 function and serves as a useful tool to dissect the functional domains in the C-terminal region of AML1.

Lymphotoxin-alpha (LTalpha) supports development of splenic follicular structure that is required for IgG responses

LTalpha-deficient (LTalpha-/-) mice show altered splenic microarchitecture. This includes loss of normal B cell-T cell compartmentalization, of follicular dendritic cell (FDC) clusters, and of ability to form germinal centers (GC). LTalpha-/- mice immunized with sheep red blood cells (SRBC) produced high levels of antigen-specific IgM but no IgG in either primary or secondary responses, demonstrating failure of Ig class switching. This inability to switch to IgG could have been due to the altered splenic microarchitecture in these mice. Alternatively, it could have been due directly to a requirement for LTalpha expression by lymphocytes cooperating in the antibody response. To investigate this, we performed reciprocal spleen cell transfers. When irradiated LTalpha-/- mice were reconstituted with wild-type splenocytes and immunized immediately with SRBC, splenic microarchitecture remained disturbed and there was no IgG response. In contrast, when irradiated wild-type animals received splenocytes from LTalpha-/- mice, follicle structure and a strong IgG response were retained. These data indicate that LTalpha-deficient B cells and T cells have no intrinsic defect in ability to generate an IgG response. Rather, the altered microenvironment characteristic of LTalpha-/- mice appears to result in impaired ability to switch to a productive IgG response. To investigate whether prolonged expression of LTalpha could alter the structure and function of spleen follicles, reciprocal bone marrow (BM) transplantation was performed. Six weeks after reconstitution of LTalpha-/- mice with wild-type BM, spleen follicle structure was partially restored, with return of FDC clusters and GC. B cell/T cell compartmentalization remained abnormal and white pulp zones were small. This was accompanied by restoration of IgG response to SRBC. Reconstitution of wild-type mice with LTalpha-/- BM resulted in loss of FDC clusters and GC, and loss of the IgG response, although compartmentalized B cell and T cell zones were largely retained. Thus, defective IgG production is not absolutely associated with abnormal B cell and T cell compartmentalization. Rather, expression of LTalpha supports the maturation of spleen follicle structure, including the development and maintenance of FDC clusters, which supports Ig class switching and an effective IgG response.

[Study of PEFV curves in 520 normal middle-aged and old humans]

Partial expiratory flow-volume(PEEV) curves and other pulmonary functions were performed for 520 (20-86 yr) normal midde-aged and old humans. The regression equations of V at FRC (VFRC, volume corrected VFRC (VFRC/FVC), flows at various lung volumes (V75, V50, V25) and specific time constants (S tau 75, S tau 50, S tau 25) were built with multiple stepwise regression analysis. VFRC decreased with increase of age, but after correction with FVC, the correlation of VFRC/FVC with age decreased. The regressions were tested with substitution of parameters with normal persons and proved to be correct. This study suggests that PEFV curve with convenient method has theoretical and practical significance.

Independent signals regulate development of primary and secondary follicle structure in spleen and mesenteric lymph node

Lymphotoxin-alpha-deficient (LT-alpha-/-) mice manifest congenital absence of lymph nodes (LNs) and Peyer's patches and disturbed spleen follicle structure. The splenic white pulp areas show loss of discrete T and B lymphocyte zones, of follicular dendritic cell (FDC) clusters, and of germinal centers (GCs). Tumor necrosis factor receptor I-deficient (TNFR-I-/-) mice show similar absence of FDC clusters and GCs but retain segregation of T and B cell zones. Rarely are mesenteric LNs found in LT-alpha-/- mice. These mesenteric LNs show segregation of T and B cell zones similar to wild-type mice. In contrast, mesenteric LNs in TNFR-I-/- mice manifest grossly disturbed organization of T and B cells. Both LT-alpha-/- and TNFR-I-/- mice lacked FDC clusters in LNs and spleen. Interestingly, although both LT-alpha-/- and TNFR-I-/- mice that had been immunized with sheep red blood cells failed to form GCs in the spleen, they both developed GC-like clusters of peanut agglutinin-positive (PNA+) cells in their LNs. Furthermore, when lethally irradiated recombination activating gene (RAG)-1-deficient (RAG-1(-/-)) mice that had received spleen cells from LT-alpha-/- mice were immunized with sheep red blood cells, they failed to generate PNA+ clusters in the reconstituted spleen but showed robust PNA+ clusters in the reconstituted LNs. These data demonstrate that the signals that regulate the development of distinct T and B cell zones as well as the signals that regulate B cell activation to produce clusters of PNA+ cells differ between the spleen and LNs.

Endodontic treatment of an unusual mandibular second molar

A case involving unusual pulpal morphology due to fusion or gemination was treated by conservative endodontic treatment. Clinically, the involved mandibular second molar had an enlarged clinical crown and an extra cusp with a deep carious lesion. Careful negotiation, instrumentation and obturation of the root canal system led to successful treatment.

[Apoptosis-antagonizing protein Bcl-2 expression, distribution in non-Hodgkin's lymphoma and its clinical significance]

OBJECTIVE

Apoptosis-antagonizing protein Bcl-2 expression, distribution in non-Hodgkin's lymphoma (NHL) and its clinical significance were studied.

METHODS

Four-stage peroxidase antiperoxidase complex (PAP) method was applied to comparatively investigate the expression and distribution of Bcl-2 protein in formalin-fixed, paraffin-embedded lymph node tissue comprising 12 cases of reactive follicular hyperplasia and 71 cases of NHL.

RESULTS

(1) Bcl-2 protein was detected in 93.0% cases of NHL with T- or B-lymphocytic phenotype. (2) Bcl-2 protein was restricted in centrocytes but not in centroblasts in 8 of 9 cases of NHL stemed from germinal centers. (3) A significant increase in Bcl-2 protein expression was found in 5 of 10 cases of diffuse large B-lymphocytic NHL showing plasmacytoid differentiation. (4) In 7 cases of follicular NHL the neoplastic nodules were strongly labeled for Bcl-2 protein and only scattered positive cells were seen in its periphery; On the contrary, in reactive lymphoid follicles Bcl-2 protein was predominantly anchored in mantle zones whereas germinal center cells were unstained.

CONCLUSION

(1) Bcl-2 protein is expressed in NHL of T- or B-cell origin. (2) Bcl-2 protein expression appears to be associated with differentiation stages of NHL. (3) Immunohistochemical staining for Bcl-2 protein conduces to differentiate between reactive and neoplastic follicles.

[An analysis of acute leukemia cells TfR expression in children]

There are a lot of transferrin receptors on the acute leukemia cells. We used the method of "Receptor Radioligand Assay" to determine the numbers of TfR binding sites on leukemia cells from 20 child patients with acute lymphocyte leukemia (ALL) and 9 with acute myeloid leukemia (AML). The results showed the numbers of TfR binding sites of AML cells were higher than those of ALL cells, and the numbers of complete remission group were lower than those of dead or relapse group. This indicated there might be a relationship between the TfR expression and the prognosis.

Infiltration of eosinophils into the asthmatic airways caused by interleukin 5

Interleukin (IL)-5 is thought to play an important role in asthmatic bronchial mucosal inflammation and is a potential therapeutic target. To investigate the effect of IL-5 on the infiltration of eosinophils in airway in vivo, we compared eosinophil counts and their activation status in airways without and after the topical instillation of recombinant human IL-5. Eight subjects with mild atopic asthma underwent initial bronchoscopy during which control bronchoalveolar lavage (BAL) fluid as well as bronchial mucosa were obtained, and at the same time, normal saline and IL-5 were administered to two sublobar segments separately. The second bronchoscopy were carried out and samples from challenged sites were taken 24 h later. It was found that the total eosinophils (BMK-13+ cells) and the activated eosinophils (EG2+ cells) in bronchial mucosa, the eosinophil numbers in BAL fluid, as well as eosinophil cationic protein (ECP) in BAL fluid from saline-challenged segments were not different from those in unchallenged segments. However, a significant eosinophilia was observed in bronchial mucosa and BAL fluid from IL-5-challenged sites. Eosinophil activation, as assessed by secretion of ECP, was also increased significantly in bronchial mucosa and BAL fluid. The results strongly suggested that IL-5 is capable of inducing eosinophil infiltration into the asthmatic airways, as well as the activation of infiltrating eosinophils.

[Rapidly expanded skin tube studied by histological and stereological observations]

In order to investigate the histological and stereological change of the rapidly expanded skin tube, 15 Japanese Long Ear Rabbits were divided into 3 groups: (1) Rapid expansion group, injecting once a day for 7 days; (2) Routine expansion group, injecting every 3 days for 21 days and (3) Control group, no expander implanted. The results showed that: in the rapid expansion group, the thickness of the epidermis and dermis were both increased, fibroblast proliferation was active, a large amount of new capillaries was observed, the collagen fiber was in loose type, and the mitochondria and rough endoplasmic net of epithelial cell were increased. In the routine expansion group, similar changes were observed. The vascular density and volume fraction were significantly higher in rapid expansion group than those in the control group (P < 0.05). It was concluded that the rapid expansion of skin tube was feasible.

[Expression of metastasis-suppressor gene nm23H1 product in nasopharyngeal carcinoma]

Using the specific monoclonal antibody of nm23H1 gene product and the immunohistochemical technique, we studied the expression of DNPK/nm23H1 and its correlation with lymph-node metastasis in nasopharyngeal carchnoma (NPC). The results revealed that, in a total of 31 cases of NPC, 13 showed positive expression with a positive rate of 41.9%. Among 21 cases of NPC with no lymph-node metastasis, 11 (52.3%) showed positive expression while only 20% (2/10) of those with lymph-node metastasis were positive, and there was significant difference between them (P < 0.01). Meantime the expression was very low or not detectable in the cancerous cells of the match lymph-node metastasis and all 10 cases showed negative expression. Statistical significant difference was found between the group of NPC with no metastasis and the group of lymph-node metastasis (P < 0.01). The above results indicated that high expression of DNPK/nm23H1 existed in the group of NPC with no metastasis while low expression existed in those with metastasis and lymph-node metastasis. It suggests that the expression of nm23H1 is inversely associated with lymph-node metastasis. The DNPK/nm23H1 may play a role in polymerization of microtubulin protein and participate in the process of cancer metastasis.