Gene Expression Profiling Identified High-mobility Group AT-hook (HMGA2) as Being Frequently Upregulated in Esophageal Squamous Cell Carcinoma

Background: Esophageal cancer is one of the most deadly malignancies worldwide and esophageal squamous cell carcinoma (ESCC) is the most frequent type. Methods: We identified up-regulated genes from gene expression profiles of HKESC-4 cell line, its parental tumor tissues, non-tumoral esophageal epithelia and lymph nodes with metastatic carcinoma using Human Genome U133 Plus 2.0 microarray. Results: Four genes [High-mobility group AT-hook 2 (HMGA2), paternally expressed 10 (PEG10), SH3 and multiple ankyrin repeat domains 2 (SHANK2) and WNT1 inducible signaling pathway protein 3 (WISP3)] were selected for further validation with real-time quantitative polymerase chain reaction (qPCR) in a panel of ESCC cell lines and clinical specimens. HMGA2 was found to be overexpressed in the panel of ESCC cell lines tested. By using immunohistochemistry, HMGA2 was found to be up-regulated in 70% of ESCC tissues (21 out of 30 cases). Conclusion: This study demonstrates successful use of gene microarray to identify and reveal HMGA2 as a novel and consistently overexpressed gene in ESCC cell lines and clinical samples.published_or_final_versio

Anti-cancer effects of a novel quinoline derivative 83b1 on human esophageal squamous cell carcinoma through Down-Regulation of COX-2 mRNA and PGE2

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Inactivation mechanisms and growth suppressive effects of p16INK4a in Asian esophageal squamous carcinoma cell lines

The inactivation mechanisms and functional role of p16INK4a in three Asian esophageal squamous cell carcinoma (ESCC) cell lines were investigated by polymerase chain reaction (PCR) amplification, DNA sequencing, methylation-specific PCR analysis, reverse transcription-PCR, Western blotting, and colony formation assays. The p16INK4a was inactivated by promoter hypermethylation in all three cell lines, a homozygous deletion of exons 2 and 3, and a frameshift deletion on exon 1, leading to transcriptional silencing or the production of mutant p16INK4a protein. Two ESCC cell lines transfected with wild type p16INK4a show significantly reduced cell growth properties. The results of the present studies support the suppressive role of p16INK4a in ESCC development. (C) 2003 Elsevier Ltd. All rights reserved

The inhibitory effect of Gleditsia sinensis on cyclooxygenase-2 expression in human esophageal squamous cell carcinoma

The anti-cancer effects of the anomalous fruit extract of Gleditsia sinensis (GSE) attributed to its apoptotic activity, telomerase inhibition and anti-angiogenesis in a panel of solid and non-solid tumor cell lines including esophageal squamous cell carcinoma (ESCC) have been intensively investigated by us in previous studies. Cyclooxygenase-2 (COX-2) has been well described as another promising target of cancer therapy for ESCC, and novel therapeutic agents are still being sought which target COX-2 expression. However, the anti-cancer effect of GSE through the suppression of COX-2 expression has not been previously investigated. In the present study, the anti-cancer effects of GSE on eight ESCC cell lines (KYSE 30, KYSE 150, KYSE 450, KYSE 510, KYSE 520, HKESC-3, HKESC-4 and SLMT-1) of Chinese and Japanese origins were first studied by MTS cytotoxicity assays. The effects of GSE on COX-2 expression levels and on the housekeeping form COX-1 were also investigated by multiplex RT-PCR analysis. Moreover, the anti-proliferative effect of GSE on KYSE 510 was also studied by anchorage-independent clonogenicity assay in soft agar. The results showed that GSE induced a dose- and time-dependent cytotoxicity on all of the eight ESCC cell lines and caused positive anti-proliferative action on KYSE 510 in the anchorage-independent clonogenicity assay, suggesting that GSE suppressed the in vitro growth of the ESCC cell lines. More importantly, the MRNA expression levels of COX-2, but not COX-1, in all of the ESCC cell lines were suppressed by GSE in a dose-dependent fashion. The overall results of the present study show that the anti-cancer effect of GSE on the ESCC cell lines is associated with the suppression of COX-2 expression, but not COX-1. Our findings also open a new chapter for the future advancement of GSE as a novel anticancer agent or as an adjuvant of traditional cancer treatments.link_to_subscribed_fulltex

Clonality of lymphomas at multiple sites in SJL mice

SJL mice are an inbred strain of mice with a high incidence of spontaneous lymphomas of B-cell type often involving multiple abdominal organs, and are therefore a useful model for studying the clonal relationship among lymphomas at multiple sites. Thirteen SJL mice with wail-developed tumors were killed at a median age of 56 weeks. Autopsy samples were taken from various enlarged lymphoid organs, and the histologic appearance of lymphomas was recorded. Using rearrangements of immunoglobulin genes (heavy and κ-light chain genes) and integration patterns of murine leukemia virus as clonal markers, 7 of the 13 informative mice showed complete clonal identity among the different sites selected from each mouse; 5 of 13 mice demonstrated at least one shared clonal band with one or more markers being different among the different sites. The histologic appearance of the lymphomas from the various sites was found to be heterogeneous, even when there was clonal identity. These findings suggest that SJL lymphomas in multiple sites within one mouse are usually derived from a single clone but may show development of subclones within a major clonal population, thus supporting the notion that clonal evolution is a common event in the course of development of lymphoid neoplasia.link_to_subscribed_fulltex

Detection of genetic alterations in esophageal squamous cell carcinomas and adjacent normal epithelia by comparative DNA fingerprinting using inter-simple sequence repeat PCR

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Progression of spontaneous lymphomas in SJL mice: Monitoring in vivo clonal evolution with molecular markers in sequential splenic samples

SJL mice are an inbred strain with a high incidence of spontaneous lymphomas of the B-cell type. We used molecular markers of clonality to study the process of tumor progression of SJL lymphomas in vivo. This was accomplished at time intervals ranging from 2 to 116 days by initial partial splenectomy (biopsy) followed by spleen sampling at the time of killing (autopsy). Immunoglobulin heavy chain (IgH) gene rearrangement and murine leukemia virus (MuLV) proviral integration patterns were used to study the clonal identities of the sequential tumor pairs in 11 informative mice by Southern blot hybridization. Of these 11 mice, 5 showed the same number of IgH gene rearrangement bands in the matched biopsy-autopsy samples, indicating the persistence of the original lesions. In 2 of 11 mice, a decrease in the number of IgH gene rearrangement bands was seen, consistent with a process of clonal selection in the original oligoclonal population. Another 2 of 11 mice showed an increase in the IgH gene rearrangement bands, indicating the emergence of either a new unrelated clone or, less likely, a subclone with secondary IgH gene rearrangement. The remaining two mice showed differences between the patterns in biopsy and autopsy samples, as assessed by IgH gene rearrangement and the proviral integration analysis. This finding suggests that the biopsied tumor had regressed and new clones had emerged. Tumor development was also associated with an increase in the number of clonal MuLV insertions in all mice except one, in which no non-germline integration band was detected. Of 11 mice, 5 showed an increase in the extent of tumor involvement by microscopic examination of the biopsy and autopsy samples; 3 showed a decrease, whereas 2 showed no change. A change in tumor morphology toward a more dedifferentiated appearance was found in only 1 of 11 mice. Overall, the results did not show a single paradigm that tumor progression followed, rather they indicated a complex and dynamic process of clonal evolution, which is likely to be a major feature of lymphoma progression in vivo.link_to_subscribed_fulltex

Functional investigation of tumor suppressive role of chromosome 9 in esophageal squamous cell carcinoma

Background: Esophageal carcinoma (EC) is a very deadly disease, but its molecular basis for tumorigenesis is still largely unknown. The microcell chromosome transfer technique is useful to functionally validate the presence of tumor suppressor genes (TSGs). Early studies indicate there might be important TSGs for EC on chromosome 9. Our study found the LOH frequency of chromosome 9 was very high and three commonly deleted regions were observed at 9p23 –22, 9q13 –22.3, and 9q34 , which suggest the probable locations of TSGs on chromosome 9 involved in esophageal tumorigenesis. Methods: Transfer of chromosome 9 into the highly tumorigenic EC cell line, SLMT-1S1, was accomplished by the method of microcell-mediated chromosome transfer (MMCT). Hybrid cells and their corresponding tumor segregants were studied for the ability to form tumors in a nude mouse model and 33 microsatellite markers were used to detect critical regions associated with their tumor suppression. Results: Comparison of the tumor suppressive hybrid cell lines and their paired tumor segregants, showed some critical regions were non-randomly eliminated, including the 9q22 .1 and 9q22 .3 regions. Conclusions: These results indicate several chromosome 9q regions may contain important TSGs for EC. These functional complementation experiments are expected to map the putative TSGs of EC