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The chromosomal aberrations underlying the development of resistance to fluoropyrimidines have not yet been identified. To characterise the genomic changes that induce the development of resistance to fluoropyrimidines, we used comparative genomic hybridisation (CGH) to analyse and compare the parent DLD-1 human colorectal cancer cell line and two cell lines, DLD-1/5-FU and DLD-1/FdUrd, which were resistant to 5-fluorouracil (5-FU) and 5-fluoro-2'-deoxyuridine (FdUrd), respectively. Both resistant cell lines showed a genetic aberration derived from the parental cell line DLD-1. Losses of 3p and 3q were also detected as additional genetic changes in the two resistant cell lines. Both resistant cell lines showed decreased orotate phosphoribosyltransferase (OPRT) activity, which is associated with the activity of the uridine monophosphate (UMP) synthase gene (3q13). These results suggested that the loss of 3q might be a genetic change responsible for the decreased OPRT activity and fluoropyrimidine cytotoxic response in cancer cells. Amplification of 18p11.2-p11.3 containing the thymidine synthase (TS) gene (18p11.32) was observed only in the DLD-1/FdUrd-resistant cell line, which overexpresses TS. These findings suggested that 18p amplification represents a genetic change associated with the overexpression of the TS protein. Our results indicate that chromosomal aberrations identified by CGH could explain, at least in part, acquired fluoropyrimidine resistance.

The metastasis suppressor gene nm23 located on chromosome 17 might be one of the targets in deletions of chromosome 17. In this study, we analyzed the expression of nm23 and chromosome 17 aberrations in gastric cancer and assessed their clinicopathological and prognostic significance. In 103 gastric cancer patients, we examined nm23 expression by immunohistochemistry and detected chromosome 17 aberrations by fluorescence in situ hybridization. There was a significant difference in the expression of nm23 among differentiated histologic types (well > moderately > poorly) (p < 0.01). Negative expression of nm23 correlated with depth of invasion (p < 0.01), lymph node metastasis (p < 0.05), lymphatic invasion (p < 0.05), venous invasion (p < 0.05), poor prognosis (p < 0.05), and chromosome 17 loss (p < 0.05). Chromosome 17 aberrations broadly correlated with clinicopathological variables and were associated with poor prognosis (p < 0.05). Univariate analyses identified nm23 (p < 0.05), chromosome 17 aberrations (p < 0.05), tumor size (p < 0.01), depth of invasion (p < 0.0001), lymph node metastasis (P < 0.001), hepatic metastasis (p < 0.01), peritoneal dissemination (p < 0.01), and lymphatic invasion (p < 0.01) as significant prognostic factors. Multivariate analysis showed that expression of nm23 and chromosome 17 aberrations were not independent prognostic indicators. Our results indicate that negative expression of nm23 and chromosome 17 numerical aberrations correlate with tumor progression and poor prognosis but are not independent prognostic indicators.

Background: Aberrations in chromosome 17 are important in carcinogenesis. We recently reported that numerical aberrations in chromosome 17 were associated with tumor progression in gastric cancer. The aim of this study was to determine the biological characteristics of gastric tumor cells with chromosome 17 numerical aberrations., Methods: Gastric tumor sections (n = 105) and metastatic lymph nodes (n = 16) were stained simultaneously for PCNA (proliferating cell nuclear antigen) and chromosome 17 centromere. Cancers were classified as follows: Group 1: PCNA(+) and numerical chromosomal aberration(+); Group 2: PCNA(-) and numerical chromosomal aberration(+); Group 3: PCNA(+) and numerical chromosomal aberration(-); and Group 4: PCNA(-) and numerical chromosomal aberration(-)., Results: The frequency of Group 1 cells correlated with lymphatic invasion (P < .0001), lymph node metastasis (P < .0001), and venous invasion (P < .01). The frequency of these cells in gastric lesions was lower than in metastatic lymph nodes (P < .01). Logistic regression analysis identified the depth of invasion followed by the frequency of Group 1 cells were two of the most significant independent factors that could predict lymph node metastasis and lymphatic invasion., Conclusions: The frequency of gastric tumor cells positive for PCNA and chromosome 17 numerical aberrations may be an indicator of the metastatic potential of gastric cancers.

We investigated the correlation between the frequency of numerical aberrations of chromosome 17 and clinicopathological features of gastric cancer. The copy number of chromosome 17 was examined with fluorescence in-situ hybridization (FISH) in frozen specimens from 100 primary gastric cancers. Chromosomal numerical aberrations were diagnosed as chromosomal loss (single signal) or gain (triple or more signals), in each cell. The frequency of numerical aberrations of chromosome 17 correlated significantly with the depth of invasion (P < 0.01), lymph node metastasis (P < 0.0001), lymphatic invasion (P < 0.001), and venous invasion (P < 0.01). Numerical aberrations of chromosome 17 were associated with lymph node metastasis in 32 early gastric cancers. Multiple regression analysis identified the depth of invasion and numerical aberrations of chromosome 17 as independent significant determinants of lymph node metastasis. Our findings suggest that alterations in chromosome 17 may be linked with tumor progression in primary gastric cancer. Our results also indicate that numerical aberrations of chromosome 17 detected by FISH provide important information about the malignant potential (in particular, lymph node metastasis) of primary gastric cancer.

The incidence of non-familial multiple primary cancer in colorectal cancer patients has increased in recent years in Japan. To clarify the characteristic genetic aberrations in such multiple cancers, we examined structural chromosomal aberrations by fluorescence in situ hybridization, using chromosome 17-specific and p53 cosmid DNA probes. We established short-term cultures of 78 surgical specimens and were able to obtain observable metaphase spreads in 23 single colorectal cancer specimens and in 6 colorectal cancer specimens from patients with double primary cancers. The frequency of chromosome 17 and/or p53 locus translocation was significantly greater in tumors with double cancer than in single colorectal cancers (P < 0.05 and P < 0.01, respectively). These aberrations in double cancers frequently appeared even at an early Dukes' stage (A and B) of colorectal carcinoma. Our results suggest that translocation of chromosome 17 and the p53 locus may be specific genetic events probably associated with carcinogenesis of multiple primary cancers in colorectal cancer.

Fluorescence in situ hybridization with biotinylated repetitive DNA probe specific for the centromeric region of chromosome 17 (p17H8: Oncor) was applied to suspended nuclei which were isolated by Shutte's method from formalin-fixed paraffin-embedded tissue. The tissues were obtained from surgically resected specimens from nine patients with non-small cell lung carcinoma. The isolated nuclei were prepared with 0.05% pepsin/0.1NHCl for 15 minutes at 37 degrees C. Subsequently, these were immersed in 70% acetic acid for 10 seconds at room temperature. After heat denature with hybridization mixture which contained 3 mu 1 DNA probe for 10 minutesat 70 degrees C, 1 x 10(6) nuclei were incubated overnight at 37 degrees C. After washing with 60% formamide/2 x SSC, the hybridized probes were labeled by FITC conjugated avidin. A number of centromeric signals of chromosome 17 wasevaluated by fluorescence microscopy (BH-2, Olympus). Furthermore, a probe-related FITC intensity was quantified using flow cytometry (FACScan, Becton Dickinson). As the results, there was good correlation between a relative fluorescence intensity determined by flow cytometry and a relative fluorescence signal by fluorescence microscopy (p < 0.05).

Numerical chromosome aberrations by interphase cytogenetic analysis have been reported in a few samples of colorectal neoplasms. No studies have defined a distinct relationship between these aberrations and clinicopathological features. To investigate the chromosome aberrations as a marker of invasiveness or prognosis, we conducted an interphase cytogenetic study using fluorescence in situ hybridization and examined 142 colorectal neoplasms consisting of 15 adenomas and 127 cancers. The target chromosomes were chromosomes 11 and 17. We also evaluated the nuclear DNA content as detected by flow cytometry, analyzed the relationship between the frequency of aneusomy and clinicopathological features, and examined the survival rate in these patients. The loss of chromosome 11 was observed in 31% of adenomas, whereas in cancers DNA aneuploidy was observed in 63% of cases, a gain of chromosome 17 was observed in 63% of cases, and a gain of chromosome 11 was observed in 42% of cases. Numerical chromosome aberrations in diploid DNA were also observed. Increased depth of invasion (>/=T3) and advanced Dukes' stage (>/=B) of malignant tumors were associated with a higher frequency of a gain of chromosome 11 (P < 0.01 and P < 0.05, respectively). Increased depth of invasion (>/=T2) in cancers was associated with a higher frequency of a gain of chromosome 17 (P < 0.05). Multivariate analysis of postoperative survival showed that a loss or gain of chromosome 11 was independently associated with a poor prognosis (P < 0.05). Numerical chromosome aberrations appear prior to the alteration of nuclear DNA content as detected by flow cytometry and influence the progression of colorectal cancers. Aneusomy of chromosome 11 is associated with poor postoperative prognosis of primary colorectal cancers.

We studied the relationship between DNA index, numerical abberation of chromosome 17 and alterations of the p53 gene in 23 non-small cell lung cancers. Diploid and aneuploid cells from 23 non-small cell lung cancer with DNA aneuploidy were flow sorted into each cell population using FACStar(plus). They were examined by PCR-SSCP analysis for p53 mutation and by microsatellite analysis for loss of heterozygosity at TP53 locus (17p13.1). They were also analyzed by FISH for copy number of chromosome 17. p53 mutations were found in aneuploid cells from the 11 cases (48%). Among them, 8 cases were informative at TP53 locus, and all showed loss of heterozygosity. Aneuploid cells from 16 cases exhibited gain of chromosome 17 copy number in FISH analysis. DNA index was significantly associated with th mean copy number of chromosome 17, suggesting that the number of chromosome 17 changed with DNA index. There were no associations between p53 mutation and DNA index or mean copy number of chromosome 17. In some cases, we also analyzed structural abberation of short arm of chromosome 17 by FISH using p53-cosmid (17p13.1) and Distal 17p (17p13.3-ptel) probes. The p53 gene located on the increased chromosome 17 was lost due to point mutation or deletion of 17p.

To investigate the characteristics of the numerical chromosome aberrations in liver metastasis of colorectal cancers, fluorescence in situ hybridization (FISH) for chromosomes 8, 18, 14/22, and 20 was performed in 18 specimens of primary regions and 18 of metastatic regions in liver metastasis of colorectal cancers compared with 15 of non-liver metastatic cancers. Among these numerical aberrations, the gain of chromosome 20, especially copy numbers exceeding three, was frequently observed in primary and metastatic cancers. Among these numerical aberrations, the gain of chromosome 20, especially copy numbers exceeding three, was frequently observed in primary and metastatic regions of liver metastasis groups compared with that of the non-liver metastasis group (P < 0.05). The incidences of gain of chromosome 20 in both regions of the liver metastasis group were higher than that of the non-liver metastasis group (P < 0.05). The gain of chromosome 20 is a frequent aberration in primary and metastatic regions in patients with liver metastatic colorectal cancers and may be available as a genetic marker for the diagnosis or prediction of liver metastasis.

Numerical aberration of chromosome 17 of 14 cases of colorectal carcinoma with multiple primary cancer (: multiple cancer) was compared with that of 35 cases of colorectal carcinoma without any other cancer (: single cancer). Fluorescence in situ hybridization with p17H8 was performed on touch smear from fresh materials. The proportion of aneusomy 17 (NCAI: numerical chromosome aberration index) in multiple cancers was significantly higher than that of single cancers (37.7 +/- 10.5% VS 46.1 +/- 8.0%; p < 0.01). Although NCAI of single cancers conformed to cancer progression (26.1 +/- 4.7% in Dukes A, 33.1 +/- 7.1% in Dukes B, 39.9 +/- 6.9% in Dukes C, and 45.7 +/- 12.0% in Dukes D), that of multiple cancers was high in all stages (44.7 +/- 7.3%, 44.4 +/- 6.8%, 50.4 +/- 11.2%, and 49.6 +/- 5.6%, respectively). Furthermore, the multiple numerical aberration of chromosome 17 in multiple cancers was more often than that of single cancers (64.3% VS 22.9%; p < 0.01).

Quantitative analysis by fluorescence in situ hybridization (FISH) on thin paraffin-embedded tissue sections, using specific probes for chromosomes 11, 17, and 18 was employed in various morphological types of early and advanced colorectal cancer to clarify tumor cytogenetics. The chromosome index (CI) was calculated as a quantitative measure of the chromosome copy number. Compared with the CI of normal epithelium, the CI of chromosome 11 in villous components of adenomas or polypoid early cancers was decreased, while the CI in flat type or advanced colorectal cancers, conversely, was increased (P < 0.05). The CI of chromosome 17 in villous components of adenomas and all cancers was higher than that of normal epithelium (P < 0.05), but the differences were not significant. In protruding advanced cancers, the CI of chromosome 18 was significantly decreased (P < 0.01) compared to the CI of normal epithelium. There was no significant chromosomal heterogeneity between the superficial and the deepest layer in each cancer. In mucosa adjacent to sessile and flat type cancers, the CI of chromosome 17 was significantly higher than the CI in normal epithelium or adenomas (P < 0.05). These results suggest that numerical chromosome aberrations are associated with the histological type of adenoma and the morphological diversity of cancer in the colorectum, and that chromosome 17 abnormality occurs in mucosa adjacent to sessile and flat cancers.

Fluorescence in situ hybridization (FISH) is an easy and efficient means of measuring numerical chromosome aberrations in the interphase nuclei of solid tumors; however, the correlation between numerical chromosome aberrations and the clinical stage of solid tumors remains unknown. Thus, in the present study, we investigated the relationship between numerical chromosome aberrations and clinicopathologic features in colorectal adenocarcinomas. FISH was applied to surgically resected colorectal cancer samples from 45 patients to evaluate the numerical aberrations of chromosomes 11 and 17. The mean age of the patients was 65.1 years, and they comprised 13 women and 32 men. According to Dukes' classification, 5 patients were categorized as stage A, 21 as stage B, 10 as stage C, and 9 as stage D. Histologically, 18 of the samples were lymph node metastasis-positive. FISH revealed numerical aberrations of chromosome 11 in 27 out of the 45 patients (60%), and those with a lower chromosome 11 number had a significantly lower incidence of lymph node metastasis (P < 0.05). Chromosome 17 proved to have numerical abnormalities in 33 of the 45 patients (73%), and those with a higher chromosome 17 number had more DNA aneuploidy (P < 0.005). This is the first report to reveal the relationship between monosomy 11 and lymph node metastasis in colorectal adenocarcinomas.