Allelic loss of chromosome region 3p21 is one of the most frequent events in the development of human cancers including lung, breast and bladder cancer. 1-3 A gene called RASSF1 has been discovered recently in this chromosome region. 4 One of the splice variants of this gene, RASSF1A, is inactivated frequently in many cancers including lung, breast and bladder by promoter hypermethylation. 5,6 Therefore both genetic and epigenetic alterations appeared to be involved in the RASSF1A inactivation. Furthermore, re-expression experiment in lung and renal cell carcinoma found that RASSF1A suppressed tumor growth in soft agar assay and in nude mice model. 5,7 These studies suggest that RASSF1A function as a tumor suppressor gene. Based on the presence of the RAS association domain in protein of RASSF1A, it is suggested that it exerts its function through RAS-mediated pathway. 4 More recently, RASSF1A is found to exert its effect by binding with novel RAS effector, Nore1 and MTS1. 8,9 Bladder cancer is the 6th most common cancer in the world. 10 Transitional cell carcinoma comprising the majority of bladder cancer, displays the multiple metachronous or synchronous features. Bladder cancer patients need a long-term follow-up with repeated urine cytology and cystoscopy for monitoring. 11 Conventional urine cytology has been the standard method for cancer detection. The sensitivity is low, however, especially for low grade transitional cell carcinoma (TCC). Therefore, a more sensitive and non-invasive method is required for cancer detection. We have reported previously that promoter hypermethylation of four cancer-related genes can be detected in voided urine of bladder cancer patients and appears to be more sensitive than conventional cytology in cancer detection. 12 In our study, we investigate the frequency of LOH in 3p21 regions and methylation status of RASSF1A in bladder cancer tissues. We also investigate the feasibility of detecting methylation of RASSF1A in voided urine and its potential role as tumor marker for bladder cancer. MATERIAL AND METHODS Tissues samplesForty bladder tumor tissues samples from transurethral resection specimens (8 frozen samples and 32 paraffin-embedded samples) were obtained at the Prince of Wales Hospital. Paraffin-embedded tissues from 6 samples of carcinoma in situ and 6 samples of normal urothelium from individuals without bladder cancer were also included. The clinical pathological data for all the tissue samples are summarized in Table I. Three human bladder cancer cell lines (T24, UMUC3 and J82) were obtained from American Type Culture Collection (Rockville, MD). Urine samplesPaired voided urine samples were collected from 14 patients ( Table I). The urine samples were spun down and the urine sediments were subjected to subsequent analysis. The corresponding urine samples were also subjected to conventional urine cytology examination by an experienced pathologist without knowledge of the methylation results. In Addition, 10 normal voided urine sediments from age-and gender-match c...
An analysis of gene expression profiles obtained from cervical cancers was performed to find those genes most aberrantly expressed. Total RNA was prepared from 29 samples of cervical squamous cell carcinoma and 18 control samples, and hybridized to Affymetrix oligonucleotide microarrays with probe sets complementary to over 20,000 transcripts. Unsupervised hierarchical clustering of the expression data readily distinguished normal cervix from cancer. Supervised analysis of gene expression data identified 98 and 139 genes that exhibited >2-fold upregulation and >2-fold downregulation, respectively, in cervical cancer compared to normal cervix. Several of the genes that were differentially regulated included SPP1 (Osteopontin), CDKN2A (p16), RPL39L, Clorf1, MAL, p11, ARS and NICE-1. These were validated by quantitative RT-PCR on an independent set of cancer and control specimens. Gene Ontology analysis showed that the list of differentially expressed genes included ones that were involved in multiple biological processes, including cell proliferation, cell cycle and protein catabolism. Immunohistochemical staining of cancer specimens further confirmed differential expression of SPP1 in cervical cancer cells vs. nontumor cells. In addition, 2 genes, CTGF and RGS1 were found to be upregulated in late stage cancer compared to early stage cancer, suggesting that they might be involved in cancer progression. The pathway analysis of expression data showed that the SPP1, VEGF, CDC2 and CKS2 genes were coordinately differentially regulated between cancer and normal. The present study is promising and provides potential new insights into the extent of expression differences underlying the development and progression of cervical squamous cell cancer. This study has also revealed several genes that may be highly attractive candidate molecular markers/targets for cervical cancer diagnosis, prognosis and therapy. ' 2005 Wiley-Liss, Inc.
Aberrant expression and altered function of transcription factors (TFs) have vital roles in many aspects of tumor development and progression. In this study, we investigated the functional significance of a TF, Yin Yang1 (YY1) in tumorigenesis of endometrioid endometrial carcinoma (EEC). We demonstrated that YY1 is upregulated in EEC cell lines and primary tumors; and its expression is associated with tumor stages. Depletion of YY1 inhibits EEC cell proliferation and migration both in vitro and in vivo, whereas overexpression of YY1 promotes EEC cell growth. These results suggest that YY1 functions as an oncogenic factor in EEC. Transcriptome analysis revealed a significant effect of YY1 on critical aspects of EEC tumorigenesis through inhibition of APC expression. Further mechanistic investigation uncovered a new epigenetic silencing mode of APC by YY1 through recruitment of EZH2 and trimethylation of histone 3 lysine 27 on its promoter region. Moreover, YY1 overexpression was found to be a consequence of miR-193a-5p downregulation through direct miR-193a-5p-YY1 interplay. Our results therefore establish a novel miR-193a-5p-YY1-APC axis, which contributes to EEC development, and may serve as future intervention target.
Emerging evidence shows that the efficacy of chemotherapeutic drugs is reliant on their capability to induce immunogenic cell death (ICD), thus transforming dying tumor cells into antitumor vaccines. We wanted to uncover potential therapeutic strategies that target ovarian cancer by having a better understanding of the standard-ofcare chemotherapy treatment. Here, we showed in ovarian cancer that paclitaxel induced ICD-associated damage-associated molecular patterns (DAMP, such as CALR exposure, ATP secretion, and HMGB1 release) in vitro and elicited significant antitumor responses in tumor vaccination assays in vivo. Paclitaxel-induced TLR4 signaling was essential to the release of DAMPs, which led to the activation of NF-kB-mediated CCL2 transcription and IkappaB kinase 2-mediated SNARE-dependent vesicle exocytosis, thus exposing CALR on the cell surface. Paclitaxel induced endoplasmic reticulum stress, which triggered protein kinase R-like ER kinase activation and eukaryotic translation initiation factor 2a phosphorylation independent of TLR4. Paclitaxel chemotherapy induced T-cell infiltration in ovarian tumors of the responsive patients; CALR expression in primary ovarian tumors also correlated with patients' survival and patient response to chemotherapy. These findings suggest that the effectiveness of paclitaxel relied upon the activation of antitumor immunity through ICD via TLR4 and highlighted the importance of CALR expression in cancer cells as an indicator of response to paclitaxel chemotherapy in ovarian cancer.
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