Expression of circadian clock genes and proteins in urothelial cancer is related to cancer-associated genes

Background: The purpose of this study was to evaluate invasive and metastatic potential of urothelial cancer by investigating differential expression of various clock genes/proteins participating in the 24 h circadian rhythms and to compare these gene expressions with transcription of other cancer-associated genes. Methods: Twenty seven paired samples of tumour and benign tissue collected from patients who underwent cystectomy were analysed and compared to 15 samples of normal bladder tissue taken from patients who underwent cystoscopy for benign prostate hyperplasia (unrelated donors). Immunohistochemical analyses were made for clock and clock-related proteins. In addition, the gene-expression levels of 22 genes (clock genes, casein kinases, oncogenes, tumour suppressor genes and cytokeratins) were analysed by real-time quantitative PCR (qPCR). Results: Considerable up- or down-regulation and altered cellular distribution of different clock proteins, a reduction of casein kinase1A1 (CSNK1A1) and increase of casein kinase alpha 1 E (CSNK1E) were found. The pattern was significantly correlated with simultaneous up-regulation of stimulatory tumour markers, and a down-regulation of several suppressor genes. The pattern was mainly seen in aneuploid high-grade cancers. Considerable alterations were also found in the neighbouring bladder mucosa. Conclusions: The close correlation between altered expression of various clock genes and common tumour markers in urothelial cancer indicates that disturbed function in the cellular clock work may be an important additional mechanism contributing to cancer progression and malignant behaviour.publishedVersio

Electrophysiological properties of ethylnitrosourea-induced, neoplastic neurogenic rat cell lines cultured in vitro and in vivo

A comparative analysis was performed on the electrophysiological properties of 11 neoplastic neurogenic cell culture lines and five other cell lines of different origin (HV1C, rat bile duct carcinoma; BICR/M1 RK , rat mammary tumor; HeLa, human cervix carcinoma; 3T3, mouse embryo; REe, rat embryo). Neurogenic lines were derived either from N-ethyl-N-nitrosourea-induced neoplasms of the nervous system or from cultured fetal rat brain cells that had undergone neoplastic transformation in vitro after exposure to Nethyl-N-nitrosourea in vivo. Electrical membrane excitability was lacking in all neurogenic cells analyzed. Their membrane potential and input resistance values were similar to those of the nonneurogenic lines. Intercellular ionic coupling was consistently observed between cells of a fibroblastoid shape or cells bearing multiple cytoplasmic processes (i.e., all neurogenic lines HV1C, BICR/M1RK , and 3T3). Epithelioid cells (i.e., HeLa, REe, an NV1C subpopulation, and a GV1C1 variant) showed no such intercellular communication. In vivo monolayer cultures on glass coverslips were obtained by a modified i.p. diffusion chamber technique. Under these conditions, the cells (with the exception of a glioma-derived cell line) retained the morphological appearance and electrophysiological properties observed in vitro

Molecular and cellular mechanisms in nervous system-specific carcinogenesis by N-ethyl-N-nitrosourea

A single pulse of N-ethyl-N-nitrosourea (ENU), applied to BDIX rats during the perinatal age, specifically results in a high incidence of neuroectodermal neoplasms in the central and peripheral nervous system (NS). The pronounced sensitivity of the developing NS suggests a dependence of the carcinogenic effect on the proliferative and/or differentiative state of the target cells at the time of the ENU pulse. The specificity of ENU for the NS cannot be due to tissue variations in the degree of carcinogen-cell interactions, since the reactive, electrophilic ethyl cation is produced by rapid, nonenzymatic decomposition of ENU indiscriminately in all tissues. Correspondingly, the initial molar fractions of ethylated purine bases are similar in the DNA of "high-risk" (perinatal brain) and "low-risk" tissues (e.g., liver; adult brain). However, while the respective half lives in DNA of N7-ethylguanine and N3-ethyladenine show only minor differences for both types of tissues, the mutagenic ethylation product 06-ethylguanine is removed from brain DNA very much more slowly than from the DNA of other tissues. Together with their high rate of DNA replication during the perinatal age, the incapacity of rat brain cells for enzymatic elimination of 06-alkylguanine from their DNA could account for an increased probability of neoplastic conversion, and hence for the NS specificity of ENU in the rat

Nervous-system-specific carcinogenesis by ethylnitrosourea in the rat: molecular and cellular aspects

A lead in the search for cellular determinants favoring neoplastic transformation may be provided by the pronounced tissue specificity of the oncogenic effect of certain carcinogens which do not require enzymatic metabolic activation, i.e., in cases where this specificity cannot be due to tissue differences in the activity of enzymes involved in the formation of the ultimate reactants. A carcinogen that fulfills this condition is the ethylating agent N-ethyl-N-nitrosourea (EtNU). Alkylation of nucleic acid constituents by N-nitroso compounds in relation to mutagenesis and carcinogenesis has received considerable attention recently

Long-term survival from adenocarcinoma of the esophagus after transthoracic and transhiatal esophagectomy

Background: The effects of transthoracic or transhiatal esophagectomy on the long-term survival of patients who had adenocarcinoma of the esophagus were compared, as were factors applicable in preoperative stratification of patient treatment. Methods: A cohort of 147 consecutive patients with adenocarcinoma of the esophagus was evaluated for esophagectomy between 1984 and 2000. The patients were followed prospectively and observed survival rates of patients with a transthoracic or transhiatal approach to esophagectomy were compared by standardized mortality ratio (SMR) and relative mortality ratio (RMR) using the expected survival of a matched Norwegian population. Results: A R0 resection was performed by transthoracic (n = 33) or a transhiatal (n = 55) esophagectomy in 88 (60%) patients with a median age of 61 (range: 35–77) and 70 (42–88) years, respectively (P <0.001). Tumor stages and other possible risk factors were similar in the two groups. Transthoracic or transhiatal esophagectomy resulted in a median survival time of 20.5 (95% confidence interval (CI): 10.4–57.6) and 16.4 (10.6–28.7) months, respectively. The respective survival rates were 31.2% and 27.8% by 5 years, and 21.3% and 16.6% by 10 years with an overall RMR of 1.14 (P = 0.63). Median survival time in the absence or presence of lymph node metastases was 74.0 (95% CI: 17.5–166.4) and 10.7 (7.9–14.9) months. The corresponding survival rates by 10 years with non-involved or involved nodes were 48.9% and 3.8% respectively (RMR 2.22, P = 0.007). Patients with a pT1-tumor were few and the survival rate was not very different from that of the general population (SMR = 1.7, 95% CI: 0.7–4.1). The median survival time of patients with a pT2-tumor was 30.4 (95% CI: 9.0–142) months and with a pT3-tumor 14 (9.2–16.4) months. The survival rates by 10 years among patients with a pT1 tumor were 57.0% (95% CI: 14.9–78.9), pT2 33.3% (11.8–52.2), and pT3 7.1% (1.9–15.5). The relative mortality for T3 stages compared to T1 stages was statistically significant (RMR = 3.22, P = 0.024). Conclusion: Transthoracic and transhiatal esophagectomy are both effective approaches for treatment of adenocarcinoma of the esophagus and survival of more than 10 years can be expected without adjuvant chemotherapy. However, increasing depth of tumor invasion and lymph node metastases reduce life expectancy

Expression of circadian clock genes and proteins in urothelial cancer is related to cancer-associated genes

Background: The purpose of this study was to evaluate invasive and metastatic potential of urothelial cancer by investigating differential expression of various clock genes/proteins participating in the 24 h circadian rhythms and to compare these gene expressions with transcription of other cancer-associated genes. Methods: Twenty seven paired samples of tumour and benign tissue collected from patients who underwent cystectomy were analysed and compared to 15 samples of normal bladder tissue taken from patients who underwent cystoscopy for benign prostate hyperplasia (unrelated donors). Immunohistochemical analyses were made for clock and clock-related proteins. In addition, the gene-expression levels of 22 genes (clock genes, casein kinases, oncogenes, tumour suppressor genes and cytokeratins) were analysed by real-time quantitative PCR (qPCR). Results: Considerable up- or down-regulation and altered cellular distribution of different clock proteins, a reduction of casein kinase1A1 (CSNK1A1) and increase of casein kinase alpha 1 E (CSNK1E) were found. The pattern was significantly correlated with simultaneous up-regulation of stimulatory tumour markers, and a down-regulation of several suppressor genes. The pattern was mainly seen in aneuploid high-grade cancers. Considerable alterations were also found in the neighbouring bladder mucosa. Conclusions: The close correlation between altered expression of various clock genes and common tumour markers in urothelial cancer indicates that disturbed function in the cellular clock work may be an important additional mechanism contributing to cancer progression and malignant behaviour