Comparison between oral and enteral tube refeeding in hyperlipidemic acute pancreatitis.

OBJECTIVE: Hyperlipidemic acute pancreatitis (HLAP) remains one of the major digestive emergencies with increasing health risks. Oral refeeding tolerant (ORT) and enteral tube feeding tolerant (ETFT) are commonly used for nutritional management in HLAP. However, the differences between ORT and ETFT are yet to be characterized. PATIENTS AND METHODS: This study included consecutive patients admitted to the Ordos Central Hospital between January 2019 and April 2023, with predefined inclusion criteria. RESULTS: A total of 335 HLAP patients were recruited according to the inclusion criteria. 268 patients were diagnosed with moderately severe acute pancreatitis (MSAP), of which 193 were in the OFT group and 75 in the ETFT group. In the ETFT group, abdominal pain and abdominal distension were significantly higher than that in the OFT group. No significant result was identified in the laboratory data. However, the OFT group showed a higher hospitalization and cost, as well as exocrine insufficiency and newly onset diabetes, than the ETFT group. CONCLUSIONS: Based on the incidence of HLAP retrieved in this study, MSAP is the major type with increasing clinical value. From the nutritional management sense, patients who received OFT showed higher hospitalization and cost, as well as lower exocrine insufficiency and newly onset diabetes.

TCF19 aggravates the malignant progression of colorectal cancer by negatively regulating WWC1.

OBJECTIVE: The aim of this study was to clarify the role of TCF19 in influencing the malignant progression of colorectal cancer (CRC) by negatively regulating WWC1. PATIENTS AND METHODS: Relative expression levels of TCF19 and WWC1 in CRC tissues and cells were detected by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). The prognosis of CRC patients was assessed by the Kaplan-Meier method. Meanwhile, the correlation between TCF19 and pathological indexes of CRC patients was evaluated. Regulatory effects of TCF19/WWC1 on viability, colony formation ability, and migration in HT29 and HCT-8 cells were evaluated. Finally, rescue experiments were conducted to elucidate a negative feedback loop of TCF19/WWC1 in influencing the progression of CRC. RESULTS: TCF19 was significantly up-regulated in CRC, while WWC1 was down-regulated. High-level TCF19 or low-level WWC1 indicated worse survival of CRC patients. Besides, TCF19 expression level was positively correlated with the occurrence of distant metastasis in CRC. Silence of TCF19 significantly attenuated proliferative and migratory capacities of HT29 cells. However, overexpression of TCF19 yielded the opposite trends in HCT-8 cells. WWC1 expression was negatively regulated by TCF19 in CRC tissues. In addition, knockdown of WWC1 abolished the regulatory effect of TCF19 on CRC cells. CONCLUSIONS: TCF19 is closely correlated with the occurrence of distant metastasis and poor prognosis of CRC. Furthermore, it aggravates the malignant progression of CRC via negatively regulating WWC1.

TEAD1/4 exerts oncogenic role and is negatively regulated by miR-4269 in gastric tumorigenesis.

TEA domain (TEAD) transcription factors are key components of the Hippo-YAP1 signaling pathway, but their functional role and regulatory mechanisms remain unclear. This study aims to comprehensively explore the expression pattern and functional role of TEAD family in gastric carcinogenesis and investigate its regulation by microRNAs (miRNAs). The mRNA and protein expression of TEAD family were examined by quantitative reverse transcription-PCR (qRT-PCR) and western blot. Their functional roles were determined by in vitro and in vivo studies. The clinicopathological association of TEAD4 in gastric cancer (GC) was studied using immunohistochemistry on tissue microarray. The prediction of miRNAs, which potentially target TEAD1/4, was performed by TargetScan and miRDB. The regulation of TEAD1/4 by miRNAs was confirmed by qRT-PCR, western blot and luciferase assays. TEAD1/4 were overexpressed in GC cell lines and primary GC tissues. Knockdown of TEAD1/4 induced a significant anticancer effect in vitro and in vivo. TEAD1 was confirmed to be a direct target of miR-377-3p and miR-4269, while TEAD4 was negatively regulated by miR-1343-3p and miR-4269. Among them, miR-4269 was the most effective inhibitor of TEAD1/4. Ectopic expression of these miRNAs substantiated their tumor-suppressive effects. In primary GC tumors, downregulation of miR-4269 was associated with poor disease-specific survival and showed a negative correlation with TEAD4. TEAD1 and TEAD4 are oncogenic factors, whose aberrant activation are, in part, mediated by the silence of miR-377-3p, miR-1343-3p and miR-4269. For the first time, the nuclear accumulated TEAD4 and downregulated miR-4269 are proposed to serve as novel prognostic biomarkers in GC.

Dexmedetomidine regulate the malignancy of breast cancer cells by activating α2-adrenoceptor/ERK signaling pathway.

OBJECTIVE: Breast cancer is one of the most aggressive and pervasive cancers identified in females. Dexmedetomidine (Dex) is an efficient anesthetic used in surgery. Our study aimed to explore the role of Dex in the malignancy of breast cancer cells in vitro and in vivo. Further, we investigate the molecular mechanism involved in the function of Dex on breast cancer cells. MATERIALS AND METHODS: The methyl thiazolyl tetrazolium (MTT) assay was applied to detect cell proliferation. The migration and invasion capacity of MDA-MB-231 cells was tested by wound healing assay and transwell assay. Western blot analysis was performed to quantify the protein expression levels of α2-adrenoceptor and ERK. RESULTS: The proliferation, migration and invasion ability of MDA-MB-231 cells was gradually increased after treatment of Dex in a dose-dependent manner in vitro. In addition, Dex could significantly elevate the volume and weight of xenotransplant tumor in vivo. Furthermore, Dex up-regulated the protein level of a2-adrenoceptor and consistently enhanced the phosphorylation of ERK without changing the total level of it. Similarity, over-expression of a2-adrenoceptor via its agonist Clonidine could mimic the function of Dex on breast cancer. CONCLUSIONS: These data suggest that Dex could promote the proliferation, migration and invasion of breast cancer cells through the activation of α2B-adrenoceptor /ERK signaling.

Tramadol regulates proliferation, migration and invasion via PTEN/PI3K/AKT signaling in lung adenocarcinoma cells.

OBJECTIVE: Tramadol is used mainly for the treatment of moderate to severe chronic cancer pain. However, the effect of tramadol on lung cancer remains unclear. Therefore, it is important to explore the mechanism accounting for the function of tramadol on lung cancer. MATERIALS AND METHODS: We investigated the effects of tramadol on the proliferation, migration and invasion in human lung adenocarcinoma cells in vitro by CCK-8 assay, wound healing assay and Transwell assay, respectively. We also explored the potential mechanism of tramadol on lung cancer cells by Western blotting. RESULTS: A549 and PC-9 cells were incubated with 2 µM tramadol for different time (0, 7, 14 and 28 d). The in vitro experiments showed that tramadol treatment significantly inhibited cell proliferation, migration and invasion in a time-dependent manner. Moreover, administration of tramadol suppressed tumor growth in vivo. The data also revealed that tramadol could up-regulate the protein expression level of PTEN and consistently inhibit the phosphorylation level of PI3K and Akt, whereas the total level of PI3K and Akt remain unchanged. CONCLUSIONS: These findings indicated that tramadol inhibited proliferation, migration and invasion of human lung adenocarcinoma cells through elevation of PTEN and inactivation of PI3K/Akt signaling.

Separating the wheat from the chaff: systematic identification of functionally relevant noncoding variants in ADHD.

Attention deficit hyperactivity disorder (ADHD) is a highly heritable psychiatric condition with negative lifetime outcomes. Uncovering its genetic architecture should yield important insights into the neurobiology of ADHD and assist development of novel treatment strategies. Twenty years of candidate gene investigations and more recently genome-wide association studies have identified an array of potential association signals. In this context, separating the likely true from false associations ('the wheat' from 'the chaff') will be crucial for uncovering the functional biology of ADHD. Here, we defined a set of 2070 DNA variants that showed evidence of association with ADHD (or were in linkage disequilibrium). More than 97% of these variants were noncoding, and were prioritised for further exploration using two tools-genome-wide annotation of variants (GWAVA) and Combined Annotation-Dependent Depletion (CADD)-that were recently developed to rank variants based upon their likely pathogenicity. Capitalising on recent efforts such as the Encyclopaedia of DNA Elements and US National Institutes of Health Roadmap Epigenomics Projects to improve understanding of the noncoding genome, we subsequently identified 65 variants to which we assigned functional annotations, based upon their likely impact on alternative splicing, transcription factor binding and translational regulation. We propose that these 65 variants, which possess not only a high likelihood of pathogenicity but also readily testable functional hypotheses, represent a tractable shortlist for future experimental validation in ADHD. Taken together, this study brings into sharp focus the likely relevance of noncoding variants for the genetic risk associated with ADHD, and more broadly suggests a bioinformatics approach that should be relevant to other psychiatric disorders.

Tramadol inhibits proliferation, migration and invasion via α2-adrenoceptor signaling in breast cancer cells.

OBJECTIVE: The aim of this study was to examine the function of tramadol on cell proliferation, migration and invasion in breast cancer cells in vitro, and to evaluate the effect of tramadol in vivo. Further, we explore the mechanism accounting for the role of tramadol on breast cancer cells. MATERIALS AND METHODS: Cell proliferation was detected by the methyl thiazolyl tetrazolium (MTT) assay. Wound healing assay and transwell assay was applied to quantify the migration and invasion ability of MDA-MB-231 cells. The expression of endogenous α2-adrenoceptor and ERK was measured by Western blotting. RESULTS: Tramadol at a clinical dose of up to 2 µM significantly inhibited the proliferation, migration and invasion in a time-dependent manner from day 0 to 28 in vitro. Moreover, tramadol suppressed the growth of xenotransplant tumor in vivo markedly. Furthermore, the protein levels of α2-adrenoceptor and phosphorylated ERK were decreased by tramadol, whereas the expression of total ERK remained unchanged. In addition, downregulation of α2-adrenoceptor by yohimbine could mimic the effect of tramadol treatment. CONCLUSIONS: Collectively, we demonstrated that tramadol could inhibit proliferation, migration and invasion of breast cancers via inactivating α2-adrenoceptor signaling pathway. Our data provide the experimental fundamental for further investigation of the anti-cancer effect of tramadol in breast cancer cells.

MiR-26b suppresses tumor cell proliferation, migration and invasion by directly targeting COX-2 in lung cancer.

OBJECTIVE: Lung cancer, including non-small cell lung cancer (NSCLC), is the leading cause of cancer-related mortality worldwide. Despite recent advances in clinical and experimental oncology, the prognosis of patients with NSCLC still remains poor and the average survival time of patients suffer from lung cancer is low. Therefore, the potential mechanism accounting for the tumorigenesis of NSCLC is still needed to be explored. MATERIALS AND METHODS: A lentiviral vector over-expressing miR-26b in A549 lung cancer cells was constructed. Cell proliferation, migration and invasion analysis were measured by cell counting kit (MTT), would healing assay and Transwell assay. Direct target of miR-26b in A549 cells was examined using bioinformatics and Luciferase assay. RESULTS: Herein, we found that over-expression of miR-26b significantly inhibited the proliferation, migration and invasion of A549 lung cancer cell in vitro and suppressed the growth of established tumors in vivo. By using bioinformatics, we found that COX-2 (Cyclooxygenase-2) is one of the potential targets of miR-26b. Moreover, miR-26b was found to negatively regulate COX-2 protein level by directly targeting its 3'UTR. In addition, depletion of endogenous COX-2 by the specific siRNA could mimic the function of miR-26b overexpression. CONCLUSIONS: Taken together, our results demonstrate that miR-26b could suppress lung cancer cells proliferation, migration and invasion by directly negative regulation of COX-2. MiR-26b could serve as a novel potential marker for NSCLC therapy.

MicroRNA-181a-mediated downregulation of AC9 protein decreases intracellular cAMP level and inhibits ATRA-induced APL cell differentiation.

AC9 is one of the adenylate cyclase (AC) isoforms, which catalyze the conversion of ATP to cAMP, an important second messenger. We previously found that the integration of cAMP/PKA pathway with nuclear receptor-mediated signaling was required during all-trans retinoic acid (ATRA)-induced maturation of acute promyelocytic leukemia (APL) cells. Here we showed that AC9 could affect intracellular cAMP level and enhance the trans-activity of retinoic acid receptor. Knockdown of AC9 in APL cell line NB4 could obviously inhibit ATRA-induced differentiation. We also demonstrated that miR-181a could decrease AC9 expression by targeting 3'UTR of AC9 mRNA, finally controlling the production of intracellular cAMP. The expression of miR-181a itself could be inhibited by CEBPα, probably accounting for the differential expression of miR-181a in NB4 and ATRA-resistant NB4-R1 cells. Moreover, we found that AC9 expression was relatively lower in newly diagnosed or relapsed APL patients than in both complete remission and non-leukemia cases, closely correlating with the leukemogenesis of APL. Taken together, our studies revealed for the first time the importance of miR-181a-mediated AC9 downregulation in APL. We also suggested the potential value of AC9 as a biomarker in the clinical diagnosis and treatment of leukemia.

Somatostatin receptor 1, a novel EBV-associated CpG hypermethylated gene, contributes to the pathogenesis of EBV-associated gastric cancer.

BACKGROUND: Somatostatin receptor 1 (SSTR1) was preferentially methylated in Epstein-Barr virus (EBV)-positive gastric cancer using promoter methylation array. We aimed to analyse the epigenetic alteration and biological function of SSTR1 in EBV-associated gastric cancer (EBVaGC). METHODS: Promoter methylation was examined by combined bisulphite restriction analysis (COBRA) and pyrosequencing. The biological functions of SSTR1 were evaluated by loss- and gain-of-function assays. RESULTS: Promoter hypermethylation of SSTR1 was detected in EBV-positive gastric cancer cell lines (AGS-EBV) with SSTR1 transcriptional silence, but not in EBV-negative gastric cancer cell lines with SSTR1 expression. Expression level of SSTR1 was restored in AGS-EBV by exposure to demethylating agent. Moreover, methylation level of SSTR1 was significantly higher in EBV-positive primary gastric cancers compared with EBV-negative gastric cancers (P=0.004). Knock-down of SSTR1 in gastric cancer cell lines (AGS and BGC823) increased cell proliferation and colony formation ability, and promoted G1 to S-phase transition, enhanced cell migration and invasive ability. In contrast, ectopic expression of SSTR1 in gastric cancer cell lines (MKN28 and MGC803) significantly suppressed cell growth in culture conditions and reduced tumour size in nude mice. The tumour suppressive effect of SSTR1 was associated with upregulation of cyclin-dependent kinase inhibitors (p16, p15, p27 and p21); downregulation of oncogenes (MYC and MDM2), key cell proliferation and pro-survival regulators (PI3KR1, AKT, BCL-XL and MET); and inhibition of the migration/invasion-related genes (integrins, MMP1 (matrix metallopeptidase 1), PLAUR (plasminogen activator urokinase receptor) and IL8 (interleukin 8)). CONCLUSION: Somatostatin receptor 1 is a novel methylated gene driven by EBV infection in gastric cancer cells and acts as a potential tumour suppressor.

Desferrioxamine induces leukemic cell differentiation potentially by hypoxia-inducible factor-1 alpha that augments transcriptional activity of CCAAT/enhancer-binding protein-alpha.

We reported recently that cobalt chloride-simulated hypoxia and mild hypoxia modified the differentiation of human acute myeloid leukemic (AML) cells, probably acting via a hypoxia-inducible factor-1 alpha (HIF-1 alpha)-dependent mechanism. In this study, we investigated the effect of desferrioxamine (DFO), an iron chelator with 'hypoxia-mimetic' activity, on the differentiation of AML cells. The results showed that DFO at nontoxic concentrations induced the differentiation of AML cell lines NB4 and U937, as assessed by morphological criteria and differentiation-associated antigens. DFO-induced differentiation parallel to the rapid accumulation of HIF-1 alpha protein in these two cell lines. Of importance, the transient transfection of HIF-1 alpha cDNA induced U937 cells to develop the differentiation-related alterations such as growth arrest and increased CD11b expression. Furthermore, the inducible expression of chromosome translocation t(8;21)-generated leukemogenic AML1-ETO fusion gene attenuated DFO-induced differentiation of U937 cells with the decrease of CCAAT/enhancer-binding protein alpha (C/EBP alpha), a critical factor for granulocytic differentiation. Using immunoprecipitation and luciferase reporter assay, HIF-1 alpha was also shown to interact physically with and to increase the transcriptional activity of C/EBP alpha. Taken together, these results provided novel evidence for a role of HIF-1 alpha in AML cell differentiation, and suggested that C/EBP alpha might be a downstream effector for HIF-1 alpha-mediated differentiation.

Clinical and cytogenetic features of 508 Chinese patients with myelodysplastic syndrome and comparison with those in Western countries.

Myelodysplastic syndrome (MDS) is a clonal hematopoietic stem cell disorder characterized by ineffective hematopoiesis and leukemia progression. Racial differences may exist on clinical pictures and the molecular events leading to MDS, which are heterogeneous. To better define the clinical and cytogenetic features in Chinese patients, a retrospective multicentric study was performed in 508 MDS cases. Compared with Western countries, Chinese patients showed younger age (median: 49 vs 65-73 years), lower percentages of RARS (2.8 vs 6.6-15.3%), and CMML (5.2 vs 11.7-30.6%). Cytogenetically, among 367 cases with evaluable data, abnormal karyotypes were found in 136 cases, including 56 numerical and 80 structural changes. Incidences of single chromosome 5 and 7 abnormalities were lower than those in Western countries (2.2 vs 17.8-42.5%). However, complex cytogenetic aberrations and chromosome translocations were frequently observed and related to poor prognosis. Both multiple chromosome deletions and translocations were detected in advanced subtypes (RAEB and RAEB-T). Analysis of 200 cases revealed a higher incidence of hepatitis-B-virus infection than that in non-MDS population (21.00 vs 9.75%). This study further confirmed: (1) different genetic/environmental backgrounds between Asian and Western MDS populations; (2) a strong predictive value of cytogenetic abnormalities on disease outcome and involvement of genomic instability in leukemia clone development.

Constitutional activation of IL-6-mediated JAK/STAT pathway through hypermethylation of SOCS-1 in human gastric cancer cell line.

The interleukin-mediated Janus kinase (JAK)/STAT pathway plays a crucial role in carcinogenesis. Recently, increased STAT3 activity was found in hepatocellular carcinoma and multiple myeloma in which there was silencing of SOCS-1 (suppressor of cytokine signalling-1) by gene promoter hypermethylation. We investigated the expression level of interleukin-6 (IL-6) and SOCS-1 in gastric cancer cell lines. Expression of SOCS-1 correlated with IL-6 level in most of the cell lines, except for AGS cells in which SOCS-1 was absent despite a high level of IL-6 production. Methylation analysis by methylation-specific polymerase chain reaction and bisulphite sequencing revealed that CpG island of SOCS-1 was densely methylated in AGS cells. Demethylation treatment by 5'aza-deoxycytidine restored SOCS-1 expression and also suppressed constitutive STAT3 phosphorylation in AGS cells. Moreover, methylation of SOCS-1 was detected in 27.5% (11 of 40) of primary gastric tumours samples, 10% (one of 10) of adjacent noncancer tissues but not in any (zero of nine) normal gastric mucosa. Methylation of SOCS-1 also correlated with the loss of mRNA expression in some primary gastric cancers. In conclusion, this is the first report to demonstrate that hypermethylation of SOCS-1 led to gene silencing in gastric cancer cell line and primary tumour samples. Downregulation of SOCS-1 cooperates with IL-6 in the activation of JAK/STAT pathway in gastric cancer.

Rapid induction of cAMP/PKA pathway during retinoic acid-induced acute promyelocytic leukemia cell differentiation.

The second messenger cyclic adenosine monophosphate (cAMP) plays an important role in cell proliferation, differentiation and apoptosis. In the present work, we evaluated the cAMP signaling in acute promyelocytic leukemia (APL) cells in the context of differentiation induced by all-trans retinoic acid (ATRA). There was a marked increase in the intracellular cAMP level within a few minutes after treatment with ATRA in APL cell line NB4 and fresh APL cells, whereas no such phenomenon was observed in NB4-R1 cells that are resistant to ATRA-induced maturation. In addition, the basal level of intracellular cAMP was lower in NB4-R1 than in NB4 cells. Mechanistic study showed that this induction of cAMP was mediated through the activation of adenylate cyclase. Moreover, we found that cAMP-dependent protein kinase (PKA) activity was quickly upregulated in parallel in ATRA-treated NB4 cells, and the phosphorylation of RARalpha by PKA could increase its transactivation effect. Use of H-89, an inhibitor of PKA, could partially suppress the transcriptional expression of ATRA target genes and ATRA-induced differentiation of APL cells. Taken together, we suggested a crosstalk between ATRA-induced cytosolic pathway and nuclear pathway in APL cell differentiation.

Cobalt chloride and low oxygen tension trigger differentiation of acute myeloid leukemic cells: possible mediation of hypoxia-inducible factor-1alpha.

Cellular and systemic O(2) concentrations are tightly regulated to maintain delicate oxygen homeostasis. Although the roles of hypoxia in solid tumors have been widely studied, few studies were reported regarding the possible effects of hypoxia on leukemic cells. Here, we showed for the first time that low concentrations of cobalt chloride (CoCl(2)), a hypoxia-mimicking agent, and 2-3% O(2) triggered differentiation of various subtypes of human acute myeloid leukemic (AML) cell lines, including NB4, U937 and Kasumi-1 cells, respectively, from M3, M5 and M2b-type AML, but CoCl(2) did not modulate AML subtype-specific fusion proteins promyelocytic leukemia-retinoic acid receptor alpha (PML-RARalpha) and AML1-ETO. Treatment with CoCl(2) also induced primary leukemic cells from some AML patients to undergo differentiation. Similar to what occurs in solid tumor cells, CoCl(2)-mimicked hypoxia also increased the level of hypoxia-inducible factor (HIF)-1alpha protein and its DNA-binding activity in leukemic cells. The CoCl(2) induction of HIF-1alpha protein and its DNA-binding activity were inhibited by 3-morpholinosydnonimine, which also blocked CoCl(2)-induced cell differentiation in leukemic cells. These results provide an insight into a possible link of hypoxia or HIF-1alpha and leukemic cell differentiation, and are possibly of significance to explore clinical potentials of hypoxia or hypoxia-mimicking agents and novel target-based drugs for differentiation therapy of leukemia.

Arsenic trioxide-induced mitotic arrest and apoptosis in acute promyelocytic leukemia cells.

Arsenic trioxide (As(2)O(3)), an effective drug for the treatment of acute promyelocytic leukemia (APL), can induce apoptosis and partial differentiation in APL cells in vitro and in vivo. However, As(2)O(3) also induces apoptosis in cancer cells other than APL with complex mechanisms, which seem to be cell type dependent. In this study, we report that APL cells (NB4 cell line) are arrested at early mitotic phase before the collapse of mitochondrial transmembrane potential (Deltavarphi(m)) and apoptosis after treatment with pharmacological concentrations (1.0-2.0 micro M) of As(2)O(3). We have also made the following new discoveries: (1) 0.5 micro M As(2)O(3) that fails to induce apoptosis has no effects on cell cycle distribution. (2) With inhibition of As(2)O(3)-induced Deltavarphi(m) collapse and apoptosis, dithiothreitol also effectively inhibits As(2)O(3)-induced mitotic arrest, suggesting that both As(2)O(3)-induced apoptosis and mitotic arrest involve proteins with thiol groups. (3) 1.5 mM caffeine that relieves cells from G(2)/M arrest also inhibits As(2)O(3)-induced Deltavarphi(m) collapse and apoptosis, (4) 1.0 micro M As(2)O(3) increases the expression of both cyclin B(1) and hCDC20 whereas it inhibits Tyr15 phosphorylation of p34(cdc2). In conclusion, our results strongly support that there is a tight link between As(2)O(3)-induced apoptosis and mitotic arrest, the latter being one of common mechanisms for As(2)O(3)-induced apoptosis in cancer cells.

Nasopharyngeal carcinoma in situ (NPCIS)--pathologic and clinical perspectives.

BACKGROUND: Dysplasia or carcinoma in situ lesions (NPCIS) of the nasopharynx have rarely been reported. The prevalence, biologic behavior, and the transformation period of the pure preinvasive lesions have not been fully explained. METHODS: All cases of NPCIS were retrospectively reviewed during the period between 1990 and 2000. The clinical features of all cases were studied. The biopsy samples were examined using light microscopy and in situ hybridization (ISH) for EBV-encoded RNA (EBER). The sera taken before and after the transformation were analyzed for anti-viral capsid antigen (VCA) EBV titers and circulating cell-free EBV DNA concentration. RESULTS: Three cases of NPCIS were identified. Two of the three cases subsequently developed into invasive NPC after initial presentation. The interval of transformation varied from 40 to 48 months. In all three cases, the specimens showed abnormal findings on light microscopy and positive staining for EBER. Elevated anti-VCA titers were present in two of the preinvasive lesions. No cell-free EBV DNA was detected in the sera of these patients during the preinvasive phase of the disease. CONCLUSIONS: Preinvasive NPC is a rare but distinct entity. Its transformation period can be as long as 4 to 5 years. Elevated anti-VCA titers, in the presence of abnormal cells on light microscopy, should alert the pathologist to perform ISH EBER studies to diagnose this rare condition.

Inverse association between cyclooxygenase-2 overexpression and microsatellite instability in gastric cancer.

This study examined the association between cyclooxygenase-2 (COX-2) overexpression and microsatellite instability (MSI) in gastric cancer. COX-2 expression was assessed by immunohistochemistry and scored in a semi-quantitative manner whereas MSI status was characterized by nine microsatellite markers. The clinicopathological features of cancers including survival data were analyzed. Of the 109 gastric cancers studied, COX-2 overexpression and high level of MSI (MSI-H) was detected in 64.2 and 22.0% cases respectively. Gastric tumors with MSI-H phenotypes had significantly lower level of COX-2 expression levels when compared to MSI-L and MSS tumors (P=0.002). Moreover, COX-2 overexpression was associated with tumor invasion beyond submucosa (P=0.045) and there was a trend favoring better survival in gastric cancers without COX-2 overexpression (P=0.07). The results from this study suggest that gastric cancer with microsatellite instability or COX-2 overexpression present with diverse clinicopathological features.