Prostate-specific membrane antigen expression in hepatocellular carcinoma,cholangiocarcinoma, and liver cirrhosis

BACKGROUNDPrimary liver cancer includes three subtypes: Hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (CCA), and combined hepatocellular carcinoma. Patients with primary liver cancer experienced poor prognosis and high mortality, so early detection of liver cancer and improved management of metastases are both key strategies to reduce the death toll from liver cancer. Prostate-specific membrane antigen (PSMA) expression in the tumor-associated neovasculature of nonprostate malignancies including liver cancer has been reported recently, but conclusive evidence of PSMA expression based on the pathological type of liver cancer remains limited.AIMTo study the expression of PSMA in HCC, CCA, and liver cirrhosis.METHODSA total of 446 formalin-fixed paraffin-embedded (FFPE) liver tumor and liver cirrhosis tissue samples were obtained retrospectively from the Pathology Department of Tongji Hospital. Immunohistochemistry was used to detect PSMA expression in these 446 FFPE liver biopsy specimens (213 HCC, 203 CCA, and 30 liver cirrhosis). The tumor compartment and the associated neovascular endothelium were separately analyzed. PSMA expression was examined by two certified pathologists, and the final results were presented in a 4-point scoring system (0-3 points). Correlation between PSMA expression and clinicopathological information was also assessed.RESULTSPSMA was expressed primarily in the neovascular endothelium associated with tumors. The positive rate of PSMA staining in HCC was significantly higher than that in CCA (86.8% vs 79.3%; P = 0.001) but was only 6.6% in liver cirrhosis (P = 0.000). HCC cases had more 3-score PSMA staining than CCA had (89/213, 41.8% vs 35/203, 17.2%; P = 0.001). PSMA expression correlated positively with the stage and grade of HCC and CCA. In both liver cancer subtypes, there were more PSMA⁺ cases in stages III–V diseases than in stages I and II. High staining intensity of PSMA was more frequently observed in liver cancers at high grade and advanced stage. There was no significant association of PSMA expression with sex, age, region, α-fetoprotein, hepatitis B surface antigen, or tumor size in both tumor subtypes.CONCLUSIONNeovascular PSMA may be a promising marker to differentiate HCC from liver cirrhosis and a prognostic marker for anti-tumor angiogenesis therapy for HCC.     

Annexin A2 silencing inhibits invasion,migration, and tumorigenic potential of hepatoma cells

AIM: To investigate the effects of Annexin A2 (ANXA2) silencing on invasion, migration, and tumorigenic potential of hepatoma cells. METHODS: Human hepatoma cell lines [HepG2, SMMC-7721, SMMC-7402, and MHCC97-H, a novel human hepatocellular carcinoma (HCC) cell line with high metastasis potential] and a normal hepatocyte cell line(LO2) were used in this study. The protein and mRNA expression levels of ANXA2 were analysed by western blotting and real-time polymerase chain reaction, re-spectively. The intracellular distribution profile of ANXA2 expression was determined by immunofluorescence and immunohistochemistry. Short hairpin RNA target-ing ANXA2 was designed and stably transfected into MHCC97-H cells. Cells were cultured for in vitro analy-ses or subcutaneously injected as xenografts in mice for in vivo analyses. Effects of ANXA2 silencing on cell growth were assessed by cell counting kit-8 (CCK-8) as-say (in vitro ) and tumour-growth assay (in vivo ), on cell cycling was assessed by flow cytometry and propidium iodide staining (in vitro ), and on invasion and migration potential were assessed by transwell assay and wound-healing assay, respectively (both in vitro ). RESULTS: The MHCC97-H cells, which are known to have high metastasis potential, showed the highest lev-el of ANXA2 expression among the four HCC cell types examined; compared to the LO2 cells, the MHCC97-H expression level was 8-times higher. The ANXA2 expres-sion was effectively inhibited (about 80%) by ANXA2-specific small hairpin RNA (shRNA). ANXA2 expression in the MHCC97-H cells was mainly localized to the cel-lular membrane and cytoplasm, and some localization was detected in the nucleus. Moreover, the proliferation of MHCC97-H cells was obviously suppressed by shR-NA-mediated ANXA2 silencing in vitro , and the tumour growth inhibition rate was 38.24% in vivo . The per-centage of MHCC97-H cells in S phase dramatically de-creased (to 27.76%) under ANXA2-silenced conditions. Furthermore, ANXA2-silenced MHCC97-H cells showed lower invasivenes     

肝细胞癌热休克蛋白70过表达与自发性癌细胞凋亡

目的探讨肝细胞癌（hepatocellularcarcinoma,HCC)热休克蛋白70（heatshockproteins70,HSP70）的表达及其与自发性癌细胞凋亡的关系。方法采用免疫组化SP法和原位末端转移酶标记法（TUNEL）检测68例HCC手术标本中HSP70表达和细胞凋亡指数,以癌旁肝组织作为对照。结果HCC和癌旁组织中HSP70阳性率分别为71%和28%,过表达分别为53%和21%,两组之间差异有非常显著意义（P＜0.01),HSP70阳性率和凋亡指数有正相关关系（r＝0.8765,P＜0.05),两者都随HCC组织学分级增高而增加。结论HCC组织中存在HSP70过表达和自发性癌细胞凋亡,两者正相关性机理尚不明了,可能是HCC生物学恶性行为的标志。     

Expression and prognostic significance of gastric-specific annexin A10 in diffuse- and intestinal-type gastric carcinoma

Background and Aims: Annexin A10 (ANXA10) and its liver‐specific short isoform (ANXA10S) had tissue‐restricted expression. The downregulation of ANXA10S is correlated with tumor progression and poor prognosis in hepatocellular carcinoma. The aim of the present study was to validate the tissue distribution and explore the role of the ANXA10 protein expression in gastric carcinoma. Methods: We examined the ANXA10 protein expression in human and animal tissues and 356 resected primary gastric carcinomas, using specific mouse and rabbit polyclonal antibodies, by immunohistochemical staining. Results: The ANXA10 protein is a nuclear protein specifically expressed in fetal and adult gastric mucosa and Brunner's gland across species, including humans, minipigs, woodchucks, and mice, and is commonly lost in gastric mucosa with intestinal metaplasia. The ANXA10 protein was expressed in 43.5% (155 cases) of gastric carcinomas; 74.2% (98/132) in the diffuse‐type gastric carcinoma (DGC), 73.7% (28/38) in the mixed‐type gastric carcinoma, and significantly lower in the intestinal‐type gastric carcinoma (IGC) and indeterminate groups, 16.8% (28/167) and 5.3% (1/19), respectively (P < 1 × 10^?8). IGC with ANXA10 expression was correlated with a higher stage (P = 0.049), particularly higher in stage IIIA/IIIB/IV IGC than lower‐stage (IA/IB/II) tumors (P = 0.005), but was not correlated with age, sex, and nodal status. In contrast, DGC with ANXA10 expression was associated with younger age, female patients, and importantly, lower tumor stage and lymph node metastasis (P = 0.007, P = 0.065, P = 0.024, and P = 0.0014, respectively). Moreover, DGC with ANXA10 expression had a better 5‐year patient survival (P = 0.0048), whereas IGC with ANXA10 expression had a lower 5‐year survival (P = 0.034). Conclusions: The ANXA10 protein expression is a novel marker of gastric differentiation, and is differentially expressed in IGC and DGC, with opposite prognostic significance.     

基质金属蛋白酶及组织抑制剂在肝癌中的表达及与预后的关系

目的：探讨基质金属蛋白酶（MMPs)及其组织抑制剂（TIMPs）在肝癌中的表达及其意义。方法：应用免疫组化、Northern印迹杂交及图像分析技术对人肝细胞癌（HCC）、肝癌细胞株7721、全反式维甲酸处理的7721细胞（RA－7721）和正常人肝细胞株L－02作MMP－1、2、9和TIMP－2的表达分析。结果;肝癌细胞浆内可表达MMP－1、2和9,但癌内阴性组5年生存率明显高于相应的阳性组（P＜0．05）。体外MMP－9mRNA在7721细胞表达明显高于RA－7721以及L－02细胞,而TIMP－2mRNA的表达与MMP－9相反,MMP－2mRNA在7721细胞中的表达仅略高于L－02细胞。结论：HCC组织内MMP－1和9的表达与患者的预后密切相关;癌细胞高表达MMP－9、低表达TIMP－2,可能是肝癌细胞浸润、转移的主要基础,而MMP-2并无重要作用。     

HOXB13 facilitates hepatocellular carcinoma progression by activating AKT/mTOR signaling pathway

Introduction and ObjectivesHepatocellular carcinoma (HCC) is one of the sixth most common malignancies worldwide and is accompanied by high mortality. Homeobox B13 (HOXB13) has been shown to be involved in the development of various cancers. This study aimed to investigate the role of HOXB13 in HCC progression.Materials and MethodsThe expression of HOXB13 in HCC tumor tissues was analyzed using qRT-PCR and immunohistochemical staining . After overexpression or downregulation of HOXB13 in HCC cell lines, cell proliferation was detected by CCK8 assay and Ki67 staining and cell invasion ability were tested by transwell assay. Western blot assay was applied to analyze the effect of HOXB13 on related signaling pathways. In addition, the role of HOXB13 on HCC in vivo was explored using a HCC mouse model. IF and WB were performed to detect cell proliferation, apoptosis and related protein expression in mice tumor tissues.ResultsThe results showed that the expression of HOXB13 was significantly increased in HCC tissues compared with adjacent tissues and positively correlated with the tumor stage and survival of HCC patients. Overexpression of HOXB13 promoted the proliferation and invasion of HCC cells and up-regulated the protein expression of AKT, mTOR and MMP2. In contrast, the downregulation of HOXB13 resulted in the opposite results. In vivo experiments, HOXB13 significantly promoted tumor growth in mice bearing HCC by promoting cell proliferation and inhibiting cell apoptosis.ConclusionsThis study suggested that HOXB13 can facilitate HCC progression by activation of the AKT/mTOR signaling pathway. HOXB13 may be a novel target for HCC therapy.     

Cloning and expression of MXR7 gene in human HCC tissue

AIM To clone and identify the whole cDNA of MXR7 gene and to find out its expression in human HCC, and normal tissues.METHODS The DNA primers were designed and synthesized according to the whole cDNA sequence of MXR7 gene. The cDNA of human HCC was taken as the template while the cDNA of MXR7 gene was synthesized by polymerase chain reaction (PCR). Recombinant DNA conforming to reading frame was constructed by connecting purified PCR product of the cDNA of MXR7 gene with expression vector pGEX-5X-1 of fusion protein. The plasmid MXR7/pGEX-5X-1 was identified by sequencing. Using 32P labeled MXR7 cDNA as probe, MXR7 mRNA expression was detected by Northern blot analysis in 12 different human normal tissues, 7 preoperatively untreated non-liver tumor tissues, 30 preoperatively untreated HCC, the paracancerous liver tissues and 12 normal liver tissues samples.RESULTS Restriction enzyme and sequence analysis confirmed that the insertion sequence in vector pGEX-5X-1 was the same as the cDNA sequence of MXR7 gene. Northern blot analysis showed no expression of MXR7 mRNA in 12 kinds of normal human tissues including liver, 7 tumor tissues in other sites and 12 normal liver tissues, the frequencies of MXR7 mRNA expression in HCC and paracancerous liver tissues were 76.6% and 13.3%, respectively.The frequency of MXR7 mRNA expression in HCC without elevation of serum AFP and in HCC ＜5cm was 90% (9/10) and 83.3% (5/6),respectively.CONCLUSION MXR7 mRNA is highly expressed in human HCC, which is specific and occurs at an early stage of HCC, suggesting MXR7 mRNA can be a tumor biomarker for HCC. The detection of MXR7 mRNA expression in the biopsied liver tissue is helpful in discovering early subclinical liver cancer in those with negative serum AFP.     

Expression of intercellular adhesive molecule1 in liver cancer tissues and liver cancer metastasis

AIM: To study the relationship between intercellular adhesive molecule-1 (ICAM-1) and liver cancer metastasis and to search for factors to predict metastasis of liver cancer.METHODS: ICAM-1 expression in fresh tissues of normal liver and hepatocellular cancer (HCC) was examined by immunoperoxidase staining. The expression of ICAM-1 in human hepatoma, tumor surrounding tissues and normal livers were semiquantitatively analyzed by Dot immuno blot. Tissue ICAM-1 expression at mRNA level was detected by Northern blot.RESULTS: All 6 cases of normal liver samples were negative in anti-ICAM-1 immunohistochemical staining, 80.0% (36/45) of HCC presented various ICAM-1 expression. The number of positive cells was a little higher in large tumors, tumors with intact capsule and metastasis, but there was no significant difference. Two cases with cancer embolus also had high ICAM-1 expression. ICAM-1 concentration in HCC (13.43 ± 0.09) was higher than that in tumor surrounding tissues (5.89 ± 0.17, P < 0.01) and normal livers (4.27 ± 0.21, P < 0.01). It was also higher in metastasis group (20.24 ± 0.30) than in nonmetastasis group (10.23 ± 0.12, P < 0.05). Northern blot analysis revealed that ICAM-1 expression at mRNA level was also higher in HCC and cancer embolus than that in tumor surrounding tissues and normal livers.CONCLUSION: Tissue ICAM-1 could indicate the growth and metastasis of HCC, and may be an index that can predict liver cancer metastasis.     

Overexpression of EphA2, MMP‐9, and MVD‐CD34 in hepatocellular carcinoma: Implications for tumor progression and prognosis

Aim: To investigate the expression of erythropoietin‐producing hepatocellular (Eph)A2 receptor, matrix metalloproteinase (MMP)‐9, and angiogenesis in hepatocellular carcinoma (HCC), in order to reveal their expression correlations with tumor invasion, metastasis, and prognosis. Methods: From January 2000 to June 2003, 129 specimens of resected tumors from the patients with HCC were obtained. Corresponding pericarcinomatous liver tissues were also obtained and selected as a control group. Expressions of EphA2, MMP‐9, and CD34 were detected with immunohistochemical staining. Microvascular density (MVD) was calculated with counting of CD34‐positive vascular endothelial cells. Results: The expressions of EphA2, MMP‐9, and MVD in the HCC tissues were significantly higher than those in the pericarcinomatous liver tissues (P < 0.01). Statistical analysis showed there were significant correlations between the expressions of EphA2, MMP‐9 and MVD in some classicclinicopathological parameters (i.e. tumor nodule, vein invasion, tumor, node, metastasis stages, extrahepatic metastasis; P < 0.05). The correlation between EphA2 and MMP‐9 expression was positive (r = 0.625, P = 0.011). Tumor MVD was closely associated with EphA2 (r = 0.281, P = 0.01) and MMP‐9 (r = 0.319, P < 0.01) expressions. In particular, EphA2, MMP‐9, and MVD expressions levels were found to be independent prognostic factors after HCC resection. Conclusions: Overexpressions of EphA2 and MMP‐9 relate to tumor progression, metastasis, and prognosis in HCC. The present study suggests that EphA2 is associated with key mediators of angiogenesis and invasion.     

MT1M and MT1G promoter methylation as biomarkers for hepatocellular carcinoma

AIM:To investigate the potential of promoter methylation of two tumor suppressor genes(TSGs)as biomarkers for hepatocellular carcinoma(HCC).METHODS:A total of 189 subjects were included in this retrospective cohort,which contained 121 HCC patients without any history of curative treatment,37 patients with chronic hepatitis B(CHB),and 31 normal controls(NCs).DNA samples were extracted from 400μL of serum of each subject and then modified using bisulfite treatment.Methylation of the promoters of the TSGs(metallothionein1M,MT1M;and metallothionein 1G,MT1G)was determined using methylation-specific polymerase chain reaction.The diagnostic value of combined MT1M and MT1G promoter methylation was evaluated using the area under the receiver operating characteristic curves.RESULTS:Our results indicated that the methylation status of serum MT1M(48.8%,59/121)and MT1G(70.2%,85/121)promoters in the HCC group was significantly higher than that in the CHB group(MT1M 5.4%,2/37,P<0.001;MT1G 16.2%,6/37,P<0.001)and NC group(MT1M 6.5%,2/31,P<0.001;MT1G 12.9%,4/27,P<0.001).Aberrant serum MT1M promoter methylation gave higher specificity to discriminate HCC from CHB(94.6%)and NCs(93.5%),whereas combined methylation of serum MT1M and MT1G promoters showed higher diagnostic sensitivity(90.9%),suggesting that they are potential markers for noninvasive detection of HCC.Furthermore,MT1M promoter methylation was positively correlated with tumor size(rs=0.321,P<0.001),and HCC patients with both MT1M and MT1G promoter methylation tended to show a higher incidence of vascular invasion or metastasis(P=0.018).CONCLUSION:MT1M and MT1G promoter methylation may be used as serum biomarkers for noninvasive detection of HCC.     

SIRT3 expression in hepatocellular carcinoma and its impact on proliferation and invasion of hepatoma cells

ObjectiveTo observe expression of SIRT3 in normal liver tissue, cirrhotic tissue and hepatocellular carcinoma (HCC) tissues, and to explore the significance of SIRT3 in primary HCC.MethodsSIRT3 expression was detected in 10 normal cases, 30 cases with, 30 HCC cases by immunohistochemical and Western-blotting method.ResultsImmunohistochemical assay showed that the SIRT3 positive expression rates were 100.0% (10/10), 96.7% (29/30) and 60.0% (18/30), respectively in normal group, paracancer group and HCC group. And the SIRT3 expression in HCC group was significantly lower than in normal group and paracancer group (P<0.05). Western-blotting showed the SIRT3 expression in cancer tissue was 0.29±0.07, significantly lower than that in paracancer group and normal group (P<0.05). SIRT3 expression was related to the differentiation degree and portal vein tumor thrombus (P<0.05).ConclusionsAbnormal expression of SIRT3 is closely related to the biological behavior of primary HCC.     

Garcinia Cambogia attenuates diet-induced adiposity but exacerbates hepatic collagen accumulation and inflammation

AIM: To investigate long-term effects of Garcinia Cambogia (GC), weight-loss supplement, on adiposity and non-alcoholic fatty liver disease in obese mice. METHODS: Obesity-prone C57BL/6J mice were fed a high-fat diet (HFD, 45 kcal% fat) with or without GC (1%, w/w) for 16 wk. The HFD contained 45 kcal% fat, 20 kcal% protein and 35 kcal% carbohydrate. They were given free access to food and distilled water, and food consumption and body weight were measured daily and weekly, respectively. Data were expressed as the mean ± SE. Statistical analyses were performed using the statistical package for the social science software program. Student’s t test was used to assess the differences between the groups. Statistical significance was considered at P < 0.05. RESULTS: There were no significant changes in body weight and food intake between the groups. However, the supplementation of GC significantly lowered visceral fat accumulation and adipocyte size via inhibition of fatty acid synthase activity and its mRNA expression in visceral adipose tissue, along with enhanced enzymatic activity and gene expression involved in adipose fatty acid β-oxidation. Moreover, GC supplementation resulted in significant reductions in glucose intolerance and the plasma resistin level in the HFD-fed mice. However, we first demonstrated that it increased hepatic collagen accumulation, lipid peroxidation and mRNA levels of genes related to oxidative stress (superoxide dismutase and glutathione peroxidase) and inflammatory responses (tumor necrosis factor-α and monocyte chemoattractant protein-1) as well as plasma alanine transaminase and aspartate transaminase levels, although HFD-induced hepatic steatosis was not altered. CONCLUSION: GC protects against HFD-induced obesity by modulating adipose fatty acid synthesis and β-oxidation but induces hepatic fibrosis, inflammation and oxidative stress.     

Identification of Annexin A1 protein expression in human gastric adenocarcinoma using proteomics and tissue microarray

AIM:To study the differential expression of Annexin A1(ANXA1)protein in human gastric adenocarcinoma.This study was also designed to analyze the relationship between ANXA1 expression and the clinicopathological parameters of gastric carcinoma.METHODS:Purified gastric adenocarcinoma cells(GAC)and normal gastric epithelial cells(NGEC)were obtained from 15 patients with gastric cancer by laser capture microdissection.All of the peptide specimens were labeled as18O/16O after trypsin digestion.Differential protein expressions were quantitatively identified between GAC and NGEC by nanoliter-reverse-phase liquid chromatography-mass/mass spectrometry(nanoRPLC-MS/MS).The expressions of ANXA1 in GAC and NGEC were verified by western blot analysis.The tissue microarray containing the expressed ANXA1 in 75 pairs of gastric carcinoma and paracarcinoma specimens was detected by immunohistochemistry(IHC).The relationship between ANXA1 expression and clinicopathological parametes of gastric carcinoma was analyzed.RESULTS:A total of 78 differential proteins were identified.Western blotting revealed that ANXA1 expression was significantly upregulated in GAC(2.17/1,P<0.01).IHC results showed the correlations between ANXA1protein expression and the clinicopathological parameters,including invasive depth(T stage),lymph node metastasis(N stage),distant metastasis(M stage)and tumour-lymph node metastasis stage(P<0.01).However,the correlations between ANXA1 protein expression and the remaining clinicopathological parameters,including sex,age,histological differentiation and the size of tumour were not found(P>0.05).CONCLUSION:The upregulated ANXA1 expression may be associated with carcinogenesis,progression,invasion and metastasis of GAC.This protein could be considered as a biomarker of clinical prognostic prediction and targeted therapy of GAC.     

RING finger and WD repeat domain 3 regulates proliferation and metastasis through the Wnt/β-catenin signalling pathways in hepatocellular carcinoma

BACKGROUNDHepatocellular carcinoma (HCC) exhibits high invasiveness and mortality rates, and the molecular mechanisms of HCC have gained increasing research interest. The abnormal DNA damage response has long been recognized as one of the important factors for tumor occurrence and development. Recent studies have shown the potential of the protein RING finger and WD repeat domain 3 (RFWD3) that positively regulates p53 stability in response to DNA damage as a therapeutic target in cancers. AIMTo investigate the relationship between HCC and RFWD3 in vitro and in vivo and explored the underlying molecular signalling transduction pathways. METHODS RFWD3 gene expression was analyzed in HCC tissues and adjacent normal tissues. Lentivirus was used to stably knockdown RFWD3 expression in HCC cell lines. After verifying the silencing efficiency, Celigo/cell cycle/apoptosis and MTT assays were used to evaluate cell proliferation and apoptosis. Subsequently, cell migration and invasion were assessed by wound healing and transwell assays. In addition, transduced cells were implanted subcutaneously and injected into the tail vein of nude mice to observe tumor growth and metastasis. Next, we used lentiviral-mediated rescue of RFWD3 shRNA to verify the phenotype. Finally, the microarray, ingenuity pathway analysis, and western blot analysis were used to analyze the regulatory network underlying HCC. RESULTSCompared with adjacent tissues, RFWD3 expression levels were significantly higher in clinical HCC tissues and correlated with tumor size and TNM stage (P < 0.05), which indicated a poor prognosis state. RFWD3 silencing in BEL-7404 and HCC-LM3 cells increased apoptosis, decreased growth, and inhibited the migration in shRNAi cells compared with those in shCtrl cells (P < 0.05). Furthermore, the in vitro results were supported by the findings of the in vivo experiments with the reduction of tumor cell invasion and migration. Moreover, the rescue of RFWD3 shRNAi resulted in the resumption of invasion and metastasis in HCC cell lines. Finally, gene expression profiling and subsequent experimental verification revealed that RFWD3 might influence the proliferation and metastasis of HCC via the Wnt/β-catenin signalling pathway.CONCLUSIONWe provide evidence for the expression and function of RFWD3 in HCC. RFWD3 affects the prognosis, proliferation, invasion, and metastasis of HCC by regulating the Wnt/β-catenin signalling pathway.     

Chromosome 14 transfer and functional studies identify a candidate tumor suppressor gene,Mirror image polydactyly 1, in nasopharyngeal carcinoma

Chromosome 14 allelic loss is common in nasopharyngeal carcinoma (NPC) and may reflect essential tumor suppressor gene loss in tumorigenesis. An intact chromosome 14 was transferred to an NPC cell line using a microcell-mediated chromosome transfer approach. Microcell hybrids (MCHs) containing intact exogenously transferred chromosome 14 were tumor suppressive in athymic mice, demonstrating that intact chromosome 14 NPC MCHs are able to suppress tumor growth in mice. Comparative analysis of these MCHs and their derived tumor segregants identified 4 commonly eliminated tumor-suppressive CRs. Here we provide functional evidence that a gene, Mirror-Image POLydactyly 1 (MIPOL1), which maps within a single 14q13.1–13.3 CR and that hitherto has been reported to be associated only with a developmental disorder, specifically suppresses in vivo tumor formation. MIPOL1 gene expression is down-regulated in all NPC cell lines and in ≈63% of NPC tumors via promoter hypermethylation and allelic loss. SLC25A21 and FOXA1, 2 neighboring genes mapping to this region, did not show this frequent down-regulated gene expression or promoter hypermethylation, precluding possible global methylation effects and providing further evidence that MIPOL1 plays a unique role in NPC. The protein localizes mainly to the nucleus. Re-expression of MIPOL1 in the stable transfectants induces cell cycle arrest. MIPOL1 tumor suppression is related to up-regulation of the p21(WAF1/CIP1) and p27(KIP1) protein pathways. This study provides compelling evidence that chromosome 14 harbors tumor suppressor genes associated with NPC and that a candidate gene, MIPOL1, is associated with tumor development.