p34<Superscript>cdc2</Superscript> expression is an independent indicator for lymph node metastasis in colorectal carcinoma

Purpose The significance of p34^cdc2 expression in human tumors has not been fully explained. The aim of the current study was to elucidate the clinicopathologic significance of immunohistochemical p34^cdc2 expression in carcinoma of the colon and rectum.Methods The immunohistochemical expression of p34^cdc2 was examined in 90 consecutive colorectal tumor cases, and p34^cdc2 expression and the clinicopathologic features of the patients and their tumors were compared.Results Lymph node metastasis was significantly more frequent in tumors expressing p34^cdc2 (47.8%, 11 of 23 tumors) than in tumors not expressing p34^cdc2 (22.4%, 15 of 67 tumors; P=0.020). Multivariate analysis demonstrated that tumor depth (P=0.008) and p34^cdc2 expression (P=0.022) were independently associated with lymph node metastases of colorectal carcinomas.Conclusions The immunohistochemical expression of p34^cdc2 is independently associated with lymph node metastasis in colorectal carcinoma.     

Clinicopathologic significance of expression of cyclooxygenase-2 in human esophageal squamous cell carcinoma

BACKGROUND/AIMS: The focus of studies on cyclooxygenase-2 (COX2) have been on its ability to mediate the biological behavior of human tumors including tumorigenesis, tumor progression, apoptosis and differentiation. The aim of the current study was to elucidate a further finding on the clinicopathologic significance of immunohistochemical expression of COX2 in esophageal squamous cell carcinoma. METHODOLOGY: The immunohistochemical expression of COX2 was examined for 68 specimens of esophageal squamous cell carcinoma (ESCC) and the correlation of COX2 expression with clinicopathologic features was examined. COX2 immunoreactivity was weak in 27 (40%) and strong in 41 (60%) of the carcinomas. RESULTS: The proportion of poorly differentiated SCCs among tumors with a strong expression of COX2 (34%, 14 of 41) was significantly higher than among tumors with a weak expression of COX2 (19%, 3 of 14, p = 0.02). The depth of the tumors (p = 0.0004), lymph node metastasis (p = 0.009) and the stage of the tumors (p = 0.001) were advanced significantly more progressively in ESCCs with a strong COX2 expression. Moreover, survival was significantly reduced (p = 0.02) among patients with strong COX2 expression when compared with the COX2 weak group. CONCLUSIONS: This study showed that strong expression of COX2 was correlated with tumor progression and poor differentiation in ESCC.     

Nuclear to cytoplasmic shift of p33<Superscript>ING1b</Superscript> protein from normal oral mucosa to oral squamous cell carcinoma in relation to clinicopathological variables

Purpose p33^ING1b, as a candidate tumour suppressor gene, has been found to be expressed a proportion of oral squamous cell carcinomas (OSCCs), however, its clinicopathological significance is not studied yet. Our aim was to investigate association of p33^ING1b expression with clinicopathological variables and particularly interesting new cysteine–histidine rich protein (PINCH) in OSCCs. Methods p33^ING1b expression was immumohistochemically examined in 20 normal oral mucosa specimens and 49 OSCCs. Results Normal squamous cells showed only p33^ING1b nuclear expression (no cytoplasmic expression), with a rate of 90% positive cases. While 24% of OSCCs appeared cytoplasmic expression (11 of them with weak nuclear staining) and the rest tumours (76%) were negative for p33^ING1b. Furthermore, the cases having lymph node metastasis showed a higher frequency of positive cytoplasmic expression than those without metastasis (P = 0.03). The p33^ING1b cytoplasmic expression was positively related to PINCH expression (P = 0.04), the cases positive for both proteins had a high rate of the metastasis (P = 0.03). Conclusions The transfer of p33^ING1b protein from the nucleus to the cytoplasm may result in loss of normal cellular function of the protein, which might play a role in the tumourigenesis and metastasis of OSCCs.     

Significance of immunohistochemical over-expression of CD44v6 as an indicator of malignant potential in esophageal squamous cell carcinoma

Purpose The aim of the current study was to find out a clinicopathologic significance of CD44v6 over-expression in esophageal squamous cell carcinoma (ESCC), which has not been elucidated fully.Methods Immunohistochemical expression of CD44v6 was examined for 81 ESCCs. Correlation of CD44 over-expression with the clinicopathologic features were investigated.Results Thirty-eight ESCCs (46.9%) had over-expression of CD44v6. The proportions of the incidence of lymph node metastasis (P=0.039), lymphatic permeation (P=0.003), and blood vessel invasion (P=0.037) in ESCCs with over-expression of CD44v6 were significantly higher than those in ESCCs without over-expression of CD44v6. The stage of the tumor in ESCCs with over-expression of CD44v6 was significantly more advanced (P=0.045). Survival rates of patients with ESCC with over-expression of CD44v6 were significantly worse (P=0.0005). Moreover, CD44v6 over-expression (P=0.048) as well as blood vessel invasion (P=0.014) and stage of the tumor (P=0.010) were factors independently associated with the unfavorable prognosis of the patients with ESCC.Conclusions Over-expression of CD44v6 can be an indicator of the malignant potential of ESCC.     

Survival Stratification Panel of Colorectal Carcinoma with Combined Expression of Carcinoembryonic Antigen,Matrix Metalloproteinases-2, and p27<Superscript>kip1</Superscript>

Purpose The prognosis varies greatly in colorectal carcinoma patients, even in the same stage. We examined the association between the expression of matrix metalloproteinases-2, carcinoembryonic antigen, p27^kip1, and clinicopathologic features in patients with colorectal carcinoma to identify a possible panel of tumor markers in predicting prognosis of colorectal carcinoma. Methods The expressions of three individual markers in 127 colorectal carcinoma cases were analyzed by immunohistochemistry method. Univariate and multivariate analysis were performed to analyze the expression with the disease-free survival time in colorectal carcinoma. Results High expression of matrix metalloproteinases-2, carcinoembryonic antigen, and low expression of p27^kip1 were related to poor prognosis in univariate analysis (P = 0.0002; P < 0.0001; P = 0.0008). The expression of matrix metalloproteinases-2, carcinoembryonic antigen, p27^kip1, and tumor differentiation were independent prognostic factors for disease-free survival by Cox regression analysis. The coexpression panel of matrix metalloproteinases-2, carcinoembryonic antigen, and p27^kip had significant prognostic value in all patients (P_AB = 0.0103; P_BC = 0.0068; P_CD = 0.0117). Multivariate analysis with Cox regression reveals that coexpression of matrix metalloproteinases-2, carcinoembryonic antigen, and p27^kip1 were independent prognostic factors as tumor differentiation in colorectal carcinoma. In different stages, coexpression tumor markers functioned in Stages II and III but not in the 19 cases of Stage I. The reason might be the number of patients was too small. Conclusions The results of this study provided further evidence that the combination of tumor markers of matrix metalloproteinases-2, carcinoembryonic antigen, and p27^kip1 was more informative than any single tumor marker alone for the disease-free survival stratification of colorectal carcinoma. Coexpression of matrix metalloproteinases-2, carcinoembryonic antigen, and p27^kip1 might be a useful survival stratification panel for clinical management. Supported by the Research fund of the Beijing Municipal Science & Technology Commission (Grant H020920030390); Beijing New Star Project on Science & Technology (Grant 2006B55). Poster presentation at Digestive Disease Week, Los Angeles, California, May 20 to 25, 2006.     

Alteration of the <Emphasis Type="Italic">p14</Emphasis><Superscript><Emphasis Type="Italic">ARF</Emphasis></Superscript> gene and p53 status in human hepatocellular carcinomas

Background The INK4a/ARF locus encodes p16^INK4a and p14^ARF, both of which are crucial for two tumor suppressor pathways, retinoblastoma (RB)/p16^INK4a and p53/ARF. Inactivation of RB/p16^INK4a was frequently reported, but alterations of the p14^ARF gene in hepatocellular carcinoma (HCC) in the Japanese population have been insufficiently analyzed.Methods To determine the role of p53/ARF alteration in hepatocarcinogenesis, we examined 44 HCCs for mRNA expression, deletion, mutation, and promoter hypermethylation of the p14^ARF gene; alterations of p53 were also analyzed in the same series of HCCs.Results Homozygous deletion, spanning from exon 1 to exon 2, was found in 1 HCC mutations within exon 2 were found in 2 HCCs, but no promoter hypermethylation was detected. All 3 HCCs with p14^ARF alteration were well differentiated. Twelve of the 44 HCCs (27.2%) showed immunohistochemical evidence of p53 alteration; however, only 1 of the tumors with p53 alteration was well differentiated. TaqMan polymarase chain reaction (PCR) indicated that the expression of p14^ARF in HCCs was higher than in that in all but three of the corresponding non-tumorous tissues (P < 0.0001), and increased expression of p14^ARF seemed to be associated with poorly differentiated phenotype. Absence of p14^ARF expression was seen in only one HCC, with homozygous deletion of the p14^ARF gene.Conclusions Compared with p53 alteration, p14^ARF alteration does not occur frequently, but may play a role in a subset of Japanese HCCs in the early stage of hepatocarcinogenesis. On the other hand, overexpression of p14^ARF was frequently observed in HCC, especially in poorly differentiated tumors, probably reflecting oncogenic stimuli in these tumors.     

Role of the Na~+/K~+/2Cl~- cotransporter NKCC1 in cell cycle progression in human esophageal squamous cell carcinoma

AIM:To investigate the role of Na+/K+/2Cl-cotransporter 1(NKCC1)in the regulation of genes involved in cell cycle progression and the clinicopathological significance of its expression in esophageal squamous cell carcinoma(ESCC).METHODS:An immunohistochemical analysis was performed on 68 primary tumor samples obtained from ESCC patients that underwent esophagectomy.NKCC1expression in human ESCC cell lines was analyzed by Western blotting.Knockdown experiments were conducted using NKCC1 small interfering RNA,and the effects on cell cycle progression were analyzed.The gene expression profiles of cells were analyzed by microarray analysis.RESULTS:Immunohistochemical staining showed that NKCC1 was primarily found in the cytoplasm of carcinoma cells and that its expression was related to the histological degree of differentiation of SCC.NKCC1 was highly expressed in KYSE170 cells.Depletion of NKCC1in these cells inhibited cell proliferation via G2/M phase arrest.Microarray analysis identified 2527 genes with altered expression levels in NKCC1depleted KYSE170.Pathway analysis showed that the top-ranked canonical pathway was the G2/M DNA damage checkpoint regulation pathway,which involves MAD2L1,DTL,BLM,CDC20,BRCA1,and E2F5.CONCLUSION:These results suggest that the expression of NKCC1 in ESCC may affect the G2/M checkpoint and may be related to the degree of histological differentiation of SCCs.We have provided a deeper understanding of the role of NKCC1 as a mediator and/or a biomarker in ESCC.     

<Emphasis Type="Italic">p16</Emphasis><Superscript><Emphasis Type="Italic">INK4A</Emphasis></Superscript> Alterations are accompanied by aberrant protein immunostaining in endometrial carcinomas

Purpose To date, the significance of p16^INK4A tumor suppressor gene inactivation in sporadic endometrial cancer (EC) has only rarely been described. In this study, we examined the alteration type and frequency of gene alterations [point mutations, aberrant promoter methylation and loss of heterozygosity (LOH)] in 50 sporadic ECs, and correlated the genetic findings with the immunohistochemical expression of the p16^INK4A protein and the classical clinicopathological features.Methods Gene mutations were detected by PCR-SSCP-sequencing analysis, promoter hypermethylation by methylation-specific PCR (MSP), and LOH by PCR of the STS-marker c5.1.Results In total, p16^INK4A alterations were found in 14 of 50 (28%) sporadic ECs. In six (12%) cases, two alterations occurred simultaneously. Partial p16^INK4A deletions were found in four of 50 (8%) samples. There was one missense mutation (codon 70; CCCGCC) and one frameshift mutation (1-bp deletion in exon 2). Only 2 of 47 (4.2%) tumors exhibited aberrant promoter methylation. An allelic loss was detected in 12 of 50 (24%) carcinomas with a higher incidence in advanced endometrial carcinomas than in early-stage uterine tumors. p16^INK4A alterations were generally accompanied by gene silencing, confirmed by aberrant protein immunostaining (r=-0.442; P=0.001). There was a significant difference in the frequency of p16^INK4A alterations between early (stage I; 18%) and advanced (stages II–IV; 58%) ECs (P=0.022). One case showed complete protein loss, but absence of genetic alterations.Conclusions Our data indicate that p16^INK4A inactivation plays a role in the tumorigenesis of the subset of sporadic ECs, particularly in cases exhibiting an aggressive clinical behavior. We demonstrate that p16^INK4A methylation can act efficiently and similarly to other genetic alterations as one of the two necessary hits according to the Knudson two-hit hypothesis of tumor suppressor gene inactivation.     

Anticancer effects of suberoylanilide hydroxamic acid in esophageal squamous cancer cells in vitro and in vivo

The effects of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, have not been studied in esophageal squamous cell cancer (ESCC). Cell viability assay; flow cytometry for cell cycle and annexin V apoptosis assays; assays for cell migration, invasion, and adhesion to extracellular matrix (ECM); and immunoblotting and immunofluorescence staining were performed in three ESCC cell lines. Tumor xenograft with semiquantitative immunohistochemistry was used to study the effects of SAHA in vivo. SAHA effectively inhibited growth of ESCC cells with half‐inhibitory concentrations (IC₅₀) ranging from 2.6 to 6.5 μmol/L. SAHA restored acetylation of histone 3 lysine 9 (H3K9Ac) and histone 4 lysine 12 (H4K12Ac) with an induction of G1 or G2 cell cycle arrest and apoptosis. Expression of cell cycle checkpoint regulatory proteins including cyclin‐dependent kinases (CDKs) and cyclins was decreased, whereas expression of cell cycle suppressors, p21, p27, and Rb was increased in ESCC cells after SAHA treatment. SAHA inhibited migration, invasion, and ECM adhesion in ESCC cells with an induction of E‐cadherin expression. SAHA significantly inhibited growth of ESCC tumors with increased expression of p21, p27, Rb, and E‐cadherin while decreasing expression of CDK4 and cyclin D1 within the murine tumors. In conclusion, SAHA had antigrowth activity against ESCC cells in vitro and in vivo while inhibiting cell migration, cell invasion, and ECM adhesion, suggesting its potential as an epigenetic therapeutic agent for ESCC.     

Immunohistochemical study of nuclear factor‐κB expression in esophageal squamous cell carcinoma: prognostic significance and sensitivity to treatment with 5‐FU

Nuclear factor‐κB (NF‐κB) is expressed in many types of cancers. It has been suggested that the expression of NF‐κB is associated with poor prognosis and resistance to chemoradiation therapies. This study evaluated the relationship between the expression of NF‐κB and the prognosis and sensitivity of esophageal squamous cell carcinoma (ESCC) to chemotherapy. One hundred and nine ESCC specimens, from patients who had undergone radical esophagectomy, were divided into two groups depending on the expression of NF‐κB. Surgical data and prognosis were compared between the two groups. NF‐κB‐positive tumors were detected in 61.5% of the cases. In 69 patients with stage II and III disease, 41 patients who were NF‐κB‐positive showed poor survival. The sensitivity of esophageal squamous cell carcinoma cell lines to 5‐fluorouracil (5‐FU) was analyzed by their NF‐κB expression, and the effect of 5‐FU was evaluated on the proliferation and activity of two cell lines of cultured ESCCs expressing NF‐κB. ESCCs with activated NF‐κB had poor sensitivity to 5‐FU. These results suggest that the increased expression of NF‐κB is associated with poor prognosis in patients with ESCC. NF‐κB may be a target for ESCC therapy because of its selective expression in this type of cancer.     

Over-expression of p53 protein in esophageal squamous cell carcinoma of women

BACKGROUND/AIMS: Most physicians naturally accept the etiological aspect that the incidence of esophageal squamous cell carcinoma (ESCC) is excessively more frequent in men than that in women. However, a definitely scientific confirmation to explain it has not been found. In the current study, we investigated the relationship between gender and p53 over-expression, which might resolve the difference between the genders in the mechanism for carcinogenesis in ESCC. METHODOLOGY: Immunohistochemical expression of p53 was examined for 134 ESCCs, and the correlation of the gender with the clinicopathologic features and over-expression of p53 was compared. RESULTS: The proportion of p53 over-expression in women was 23.8% (5 out of 21) and this incidence proportion was significantly lower than that in men (48.7%, 55 out of 113; p=0.031). CONCLUSIONS: This biological modulation might be correlated with the lower incidence of ESCC in women.     

Cortactin overexpression in the esophageal squamous cell carcinoma and its involvement in the carcinogenesis

SUMMARY.  The aim of this study is to examine whether dysregulated expression of cortactin occurs in esophageal squamous cell carcinoma (ESCC) and is involved in the development of ESCCs. An immunohistochemistry study for cortactin expression was performed on 46 pairs of surgically resected non-tumor and ESCC tumor tissues and murine tumors of esophagi induced by a carcinogen. The results show increased cortactin expression in 20 and in 22 to a lesser extent, out of a total 46 ESCC tumor tissues. Increased cortactin was also detected in the premalignant lesions, the early stage dysplasia and carcinoma in situ , of ESCC tumor tissues. Differential polymerase chain reaction results showed slight increases in the EMS1 gene only in two of 10 ESCC tumor tissues, suggesting that EMS1 gene amplification is not the only mechanism for cortactin overexpression. In the mouse model induced by treatment with 4-nitroquinoline 1-oxide and arecoline, increased cortactin was detected in the epithelia with hyperkeratosis, papillomas, and ESCCs with invasion into the submucosa, respectively. Overall, we observed cortactin overexpression in early and late stages of human ESCCs and carcinogen-induced murine ESCCs, suggesting a role for cortactin in esophageal carcinogenesis.     

Nuclear BAG-1 expression is a biomarker of poor prognosis in esophageal squamous cell carcinoma

Apoptosis is one of the critical biological factors that correlate with the biological behavior of malignant tumors including cancer progression and clinical outcome. The present study was performed to clarify the clinical implications of BAG-1, a bcl-2 binding protein in esophageal squamous cell carcinoma (ESCC). Seventy-one cases with ESCC were investigated. Immunohistochemical study of BAG-1 was performed on resected specimens. The expression pattern of BAG-1 in nuclei and/or cytoplasm was analyzed and correlated with TNM classification, vessel invasion, survival period after surgery. BAG-1 expression in the nuclei was related to the depth of tumor invasion (P = 0.0381) but not to any other clinicopathologic parameters. The cytoplasmic staining pattern of BAG-1 exhibited no correlation with clinicopathologic parameters. Univariate analysis (P < 0.05), but not multivariate analysis, revealed significantly poor prognosis for ESCC cases exhibiting positive nucleic staining for BAG-1. Our data suggests that BAG-1 expression in the nuclei of ESCC plays an important role in tumor development and may be useful for predicting the prognosis after surgery.     

p21<Superscript>WAF1/CIP1</Superscript> is more effective than p53 in growth suppression of mouse renal carcinoma cell line Renca in vitro and in vivo

Purpose Although there are many controversial reports about the effect of p53 and p21^WAF1/CIP1 overexpression in different human tumor cells, the p53 gene is shown to be a more effective candidate for cancer gene therapy because of its more pronounced ability to induce apoptosis. In the present study, we present the effect of p53 and p21^WAF1/CIP1 overexpression on mouse renal carcinoma cells in vitro and in vivo.Methods p53 and p21^WAF1/CIP1 genes were introduced into Renca cells using adenoviral vectors (Ad5CMV-p53 and Ad5CMV-p21). The induction of apoptosis was measured using Annexin V assay and DNA fragmentation analysis. The expression of proteins was examined using immunocytochemistry and Western blot methods. The ability of adenoviral vectors to inhibit tumorigenicity of Renca cells, as well as the growth of pre-established tumors was measured.Results In vitro growth assays revealed higher growth suppression after Ad5CMV-p21 infection. Although both vectors induced apoptosis, Ad5CMV-p53 was slightly more efficient. In vivo studies in Balb/c mice, demonstrated that tumorigenicity was completely suppressed by Ad5CMV-p21. Besides this, Ad5CMV-p21 significantly inhibited the growth of established tumors, while Ad5CMV-p53 did not.Conclusions These data suggest that p21^WAF1/CIP1 is a more potent growth suppressor than p53 of mouse tumor cells Renca. The divergent responses of tumor cells to p21^WAF1/CIP1 overexpression could be due to various networks that differ between species.     

Correlation of p53, MDM2 and p14ARF protein expression in human esophageal squamous cell carcinoma

Purpose  

To determine the interrelationships of p53, MDM2, and p14^ARF protein expression in primary esophageal squamous cell carcinoma (ESCC) and their prognostic value in ESCC.     

Association of mu‐opioid receptor expression with lymph node metastasis in esophageal squamous cell carcinoma

The mu‐opioid receptor (MOR), a membrane‐bound G protein‐coupled receptor, is the main target for opioids in the nervous system. MOR1 has been found in several types of cancer cells and reported to be involved in tumor progression and metastasis. However, the expression and clinical significance of MOR1 in esophageal squamous cell carcinoma (ESCC) remain unclear. In our study, the expression of MOR1 was confirmed in ESCC cell lines (KYSE180, KYSE150, and EC109) by Western blot. MOR1 was also detected on tissue microarrays of ESCC samples in 239 cases using immunohistochemical staining. We found that MOR1 was mainly located in the cytoplasm and occasionally occurred in the membrane or nucleus of ESCC cells. Moreover, results indicated that MOR1 expression in the cytoplasm was associated with lymph node metastasis (R = 0.164, P = 0.008, Kendall's tau‐b‐test). No more associations were found between MOR1 expression status and other clinical parameters. However, no statistical significant differences were found between MOR1 expression in the cytoplasm, nucleus/membrane, and the overall survival of ESCC patients (P = 0.848; P = 0.167; P = 0.428, respectively, log‐rank test). Our results suggest that the cytoplasmic MOR1 may be a high‐risk factor for lymph node metastasis of ESCC patients. We also hypothesize that MOR1 agonists used in ESCC patients should be prudent, and opioid receptor antagonists may be novel therapeutic drugs for ESCC patients.     

Squamous cell carcinoma in Barrett's esophagus: field effect versus metastasis

Barrett's esophagus (BE) is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). Risk factors for EAC overlap with those for esophageal squamous cell carcinoma (ESCC), but ESCC is surprisingly rare in BE. We report two cases of ESCC directly surrounded by BE. Both patients had a previous medical history of cancers, i.e., head and neck squamous cell carcinomas, and were using alcohol and smoking tobacco. Using immunohistochemistry for p63, CK5, CK7, and CDX2, it was confirmed that these carcinomas were pure squamous cell carcinomas, and not EACs or esophageal adenosquamous carcinomas arising from BE. Using TP53 mutation and loss of heterozygosity analysis, we established that the ESCCs in BE were not metastases of the previously diagnosed head and neck squamous cell carcinomas but de novo primary ESCCs. This study shows the strength of molecular analysis as an adjunct to the histopathologic diagnosis for distinguishing between metastases of prior cancers and primary cancers. Furthermore, these cases imply that presence of BE is not protective with regards to developing ESCC in the lower one third of the esophagus. We suggest that their ESCCs arose from islets of squamous epithelium in BE.     

Expression and prognostic relevance of p21WAF1 in stage III esophageal squamous cell carcinoma

The prognostic effect of p21^WAF1 expression on esophageal squamous cell carcinoma patients is controversial. Further clarifying the effect of this protein is beneficial for optimizing the patient outcomes. In the current study, we investigated the expression of p21^WAF1 protein in 189 specimens of stage III ESCC by immunohistochemistry. As shown by the Kaplan–Meier curve, the overall survival rate of the positive‐expression group was significantly higher than that of the negative‐expression group (P < 0.05). No significant correlation was observed between p21^WAF1 expression and clinicopathological parameters in terms of gender, age, tumor location, tumor grade, pathological stage, and number of regional lymph node metastases (P > 0.05). We concluded that p21^WAF1 played an intricate role in the tumorigenesis and development of ESCC. p21^WAF1 could serve as a positive prognostic predictor for stage III ESCC patients.     

Production of matrix metalloproteinase-9 by cord blood CD34<Superscript>+</Superscript> cells and its role in migration

The transmigration of hematopoietic progenitor cells is a crucial step in the homing of transplanted stem cells into bone marrow (BM) microenvironment; however, the molecular basis for this is not fully understood. Matrix metalloproteinases (MMPs), which are implicated in the migration of leukocytes, are important in degrading components of extracellular matrix molecules. In this study, using zymographic analysis and enzyme-linked immunosorbent assay (ELISA), we investigated the production of MMP-9 in CD34⁺ cells from cord blood (CB) and BM, compared their spontaneous migration across a reconstituted basement membrane-coated filter in transwell, and studied the role of MMP-9 in the transmigration. Zymography and ELISA showed that MMP-9 is produced by freshly isolated CD34⁺ stem/progenitor cells obtained from CB. CB CD34⁺ cells showed significantly higher migrational capacity than BM CD34⁺ cells (p=0.008). Furthermore, the migrational ability of CB CD34⁺ cells over the extracellular matrix (ECM) was significantly inhibited by the inhibitor of MMP, o-phenanthroline and anti-MMP-9 monoclonal antibody (73.3±11.8% and 37.5±10.4% inhibition, respectively). Our results strengthen the potential role of MMP-9 in the higher migrational capacity of CB CD34⁺ cells, which may be beneficial to homing of these cells to the BM environment.     

Effects of hyper- and hypothyroidism on acetylcholinesterase, (Na<Superscript>+</Superscript>, K<Superscript>+</Superscript>)- and Mg <Superscript><Emphasis Type="Bold">2+</Emphasis></Superscript>-ATPase activities of adult rat hypothalamus and cerebellum

Thyroid hormones (THs) are recognized as key metabolic hormones, and the metabolic rate increases in hyperthyroidism, while it decreases in hypothyroidism. The aim of this work was to investigate how changes in metabolism induced by THs could affect the activities of acetylcholinesterase (AChE), (Na⁺, K⁺)- and Mg²⁺-ATPase in the hypothalamus and the cerebellum of adult rats. Hyperthyroidism was induced by subcutaneous administration of thyroxine (25μg/100 g body weight) once daily for 14 days, while hypothyroidism was induced by oral administration of propylthiouracil (0.05%) for 21 days. All enzyme activities were evaluated spectrophotometrically in the homogenated brain regions of 10 three-animal pools. Neither hyper-, nor hypothyroidism had any effect on the examined hypothalamic enzyme activities. In the cerebellum, hyperthyroidism provoked a significant decrease in both the AChE (−23%, p < 0.001) and the Na⁺, K⁺-ATPase activities (−26%, p < 0.001). Moreover, hypothyroidism had a similar effect on the examined enzyme activities: AChE (−17%, p < 0.001) and Na⁺, K⁺-ATPase (−27%, p < 0.001). Mg²⁺-ATPase activity was found unaltered in both the hyper- and the hypothyroid brain regions. In conclusion: neither hyper-, nor hypothyroidism had any effect on the examined hypothalamic enzyme activities. In the cerebellum, hyperthyroidism provoked a significant decrease in both the AChE and the Na⁺, K⁺-ATPase activities. The decreased (by the THs) Na⁺, K⁺-ATPase activities may increase the synaptic acetylcholine release, and thus, could result in a decrease in the cerebellar AChE activity. Moreover, the above TH-induced changes may affect the monoamine neurotransmitter systems.