Biomedical subjects

J Isola

Publications and source records attributed to J Isola.

At least 73 records · Page 4Linked to original sources

PubMed1997

Increased cell proliferation activity and decreased cell death are associated with the emergence of hormone-refractory recurrent prostate cancer.

The tumour growth kinetics (cell proliferation and apoptosis) of ten hormone-refractory locally recurrent prostate cancers were compared with their matched untreated primary tumour specimens. All recurrent tumours had a higher cell proliferation activity, as defined by Ki-67 immunohistochemistry, than corresponding primary tumours from the same patients. The mean cell proliferation activity in recurrences (13.5 +/- 3.8 per cent) was over two times higher (P < 0.0001) than that in primary tumours (5.5 +/- 2.4 per cent), suggesting that cell clones which progress during androgen withdrawal are actively stimulated to proliferate. The mean percentage of apoptotic cells, as estimated by the in situ end-labelling technique, was 5.4 +/- 4.7 per cent in untreated primary tumours, whereas it was 2.3 +/- 1.5 per cent in locally recurrent tumours (P = 0.05). In all but two cases, the apoptotic index was lower in recurrent than in corresponding primary tumours, suggesting that recurrent prostate carcinomas are able to avoid apoptosis in the androgen-deprived environment. In conclusion, the clinical progression of prostate cancer during androgen withdrawal is associated with increased cell proliferation and decreased apoptosis.

Antineoplastic Agents, Hormonal↗

PubMed1997

Genetic aberrations in pediatric acute lymphoblastic leukemia by comparative genomic hybridization.

Classical cytogenetic analysis plays an important role in the diagnosis and classification of childhood acute lymphoblastic leukemia (ALL). However, poor in vitro growth of the malignant cells and suboptimal quality of metaphase spreads may sometimes cause false-negative findings (normal karyotype). We used comparative genomic hybridization (CGH) to study whether this new method is able to detect and characterize genetic aberrations not detected by karyotyping. CGH showed clonal genetic aberrations in 8 of 13 cases, most of which showed gains of several chromosomes, indicating hyperdiploidy. The sensitivity of CGH was sufficient to detect a small interstitial deletion of 6q. One karyotypically complex case was resolved by CGH showing a high-level amplification of DNA sequences originating from the 12p12-13. Interphase fluorescence in situ hybridization (FISH) analyses confirmed the CGH findings in 2 cases, validating the accuracy of CGH. In conclusion, CGH experiments established the known fact that hyperdiploidy is the most common finding in pediatric ALLs and that CGH may detect aberrations that are not seen in the G-banded karyotype. CGH was also able to further characterize genetic aberrations such as gene amplification, which is occasionally involved in pediatric ALL as well as in other leukemias.

Child↗

PubMed1997

Effect of age on the survival of breast cancer patients.

Despite numerous studies, the effect of patient age on the prognosis of breast cancer is still uncertain. The aim of this study was to assess the influence of age on long-term relative survival, to control the results for the extent of disease at diagnosis and assess the association between biological markers and age of the patients. A population-based survival study was made to assess the 5- and 10-year relative survival. All 17,856 female breast cancer patients diagnosed in Finland and reported to the Finnish Cancer Registry in 1977-1986 were included. The results were controlled for the extent of the disease. The markers of biological aggressiveness of tumours and patients' age were correlated in a prospectively collected subset of 2107 patients from the Tampere University area. The relative 5-year and 10-year survival rates (RSRs) were highest in women 46-50 years of age, whereas there was no significant difference between younger and older age groups. No consistent survival trends were observed among the age groups in local, node-negative disease, whereas in node-positive disease the 10-year relative survival was best for women 41-45 years (49%) and poorest in women over 75 years (35%). The youngest age groups were significantly more often oestrogen receptor-negative, but only small differences were observed for S-phase fraction and progesterone receptor positivity.

Adolescent↗

PubMed1997

Androgen receptor gene amplification in a recurrent prostate cancer after monotherapy with the nonsteroidal potent antiandrogen Casodex (bicalutamide) with a subsequent favorable response to maximal androgen blockade.

OBJECTIVE: We recently found amplification of the androgen receptor (AR) gene in approximately 30% of locally recurrent prostate carcinomas from patients treated by conventional androgen deprivation (castration) therapy, whereas none of the untreated primary prostate tumors showed this amplification. This suggests that AR gene amplification was selected during androgen deprivation therapy. The present case study represents our initial approach to evaluate the role that AR amplification may play in therapy resistance after other forms of endocrine therapy. MATERIAL AND METHODS: Specimens from both a primary and a subsequent locally recurrent tumor were studied for amplification of the AR gene by fluorescence in situ hybridization from a prostate cancer patient who experienced tumor progression after monotherapy with the potent antiandrogen bicalutamide (Casodex, a trade mark, the property of Zeneca Ltd). RESULTS AND CONCLUSIONS: High-level amplification of the AR gene was found in the recurrent tumor, whereas no evidence of amplification was found in the primary tumor. After recurrence, the patient first received chemotherapy (ifosfamide) for 15 weeks with no response, followed by maximal androgen blockade (MAB). The latter therapy resulted in a favorable short-term response. This case study has the following implications which warrant further research: (1) AR amplification may be selected not only by castration but also by therapy with a competitive peripheral androgen-receptor-blocking agent, and (2) recurrent tumors with AR amplification may be particularly likely to benefit from MAB as a second-line therapy.

Adenocarcinoma↗

PubMed1997

Genetic changes in intraductal breast cancer detected by comparative genomic hybridization.

Ductal carcinoma in situ (DCIS) is considered a direct precursor of invasive ductal breast cancer (IDC). We combined tissue microdissection and comparative genomic hybridization to identify genetic changes in five DCIS lesions with no invasion and in two that were adjacent to IDC. Extensive genetic changes characterized pure DCIS cases with gains of 1q, 6q, 8q, and Xq as well as losses of 17p and chromosome 22 being most often involved. Except for the Xq gain, these changes are also common to IDC. Separate analysis of DCIS and IDC components in the same tumor revealed an almost identical pattern of genetic changes in one case, whereas substantial differences were found in another. We conclude that many of the common genetic changes in IDC may take place before development of invasive growth. However, a simple linear progression model may not always account for the DCIS-IDC transition.

Breast Neoplasms↗

PubMed1997

Optimizing DOP-PCR for universal amplification of small DNA samples in comparative genomic hybridization.

The standard comparative genomic hybridization (CGH) protocol relies on availability of macroscopic tumor samples, which do not contain too much interfering normal cells. Recently, CGH after universal amplification of genomic DNA with degenerate oligonucleotide primed PCR (DOP-PCR) has been used to detect genetic aberrations in microdissected tumor specimens. However, owing to the technical difficulties, CGH results of only few microdissected samples have so far been published. We have developed an improved protocol for DOP-PCR, which includes direct incorporation of fluorochrome-conjugated nucleotides into the PCR product. Among the four polymerase enzymes tested. ThermoSequenase gave the best yield, with PCR products ranging from 100-4,000 bp. A two-step PCR-procedure was used, consisting of a preamplification with low stringency conditions followed by amplification in more stringent conditions. The method was first validated by hybridizing DOP-PCR-amplified normal DNA against nick-translated reference DNA, which showed uniform amd even hybridization result for all chromosomes. Comparison of DOP-PCR CGH to conventional CGH in MCF-7 breast cancer cell line further indicated that genetic aberrations can be reliable detected after DOP-PCR amplification. The sensitivity of the DOP-PCR-CGH was tested by serial dilution of MCF-7 DNA. Fifty picograms of sample DNA (corresponding roughly to two MCF-7 cells) was sufficient for high quality CGH. Experiments with cells microdissected from intraductal breast cancer demonstrated that carcinoma cells from 1 to 2 ducts were sufficient for a successful DOP-PCR CGH analysis. We conclude that the improved DOP-PCR-CGH protocol provides a powerful tool to study genetic aberrations in different histological subpopulations of malignant as well as precancerous lesions. DOP-PCR also improves the success rate of conventional paraffin-block CGH, because a poor quality or a too low yield of extracted DNA can be compensated by universal DNA amplification by DOP-PCR.

DNA, Neoplasm↗

PubMed1997

P53 accumulation, deoxyribonucleic acid ploidy and progression of bladder cancer.

PURPOSE: The alterations in deoxyribonucleic acid (DNA) ploidy and p53 expression during progression of bladder cancer were determined. MATERIALS AND METHODS: p53 Expression and DNA ploidy were studied in 51 patients with transitional cell carcinoma of the bladder (mean followup 5 years). Of 29 primarily superficial tumors (stages Ta and T1) 17 became subsequently invasive (greater than stage T2) within an average of 4 years (group 2) and 12 recurred superficially with no sign of progression during a mean followup of 10.8 years (group 1). Of the patients 22 had metastatic disease (group 3). Samples of tumors at diagnosis and recurrence or progression were analyzed by immunohistochemistry and flow cytometry. RESULTS: p53 Accumulation was detected at diagnosis in 29 of the 51 patients (57%), including 3 of 12 (25%) in group 1, 5 of 17 (29%) in group 2 and 14 of 22 (64%) in group 3. The p values for the differences between groups 1 and 3, and 2 and 3 were 0.07 and 0.054, respectively. Abnormal DNA contents were noted in 3 of 12 (25%), 11 of 17 (65%) and 16 of 22 (73%) patients in groups 1 to 3, respectively, and the differences between groups 1 and 2, and 1 and 3 were statistically significant. Using these 2 genetic markers, we found genetic progression to be uncommon in groups 1 and 3, whereas in group 2 an initially negative p53 staining became positive at invasion into the muscle in 5 of 12 patients (42%). CONCLUSIONS: The tumors in patients with superficial recurrences are mostly diploid and negative for p53, and those with metastasis are nondiploid and positive for p53 from the beginning, while further genetic progression is uncommon. However, p53 tends to accumulate frequently when the tumor begins to invade the muscle. There seems to be a need for caution against under staging an apparent stage T1 tumor that is positive for p53.

Carcinoma, Transitional Cell↗

PubMed1997

Accumulation of genetic changes is associated with poor prognosis in grade II astrocytomas.

Unexpectedly aggressive clinical course of some grade II astrocytomas is a diagnostic dilemma for routine histopathology. Because increasing tumor malignancy is a consequence of progressive accumulation of chromosomal alterations, we investigated whether aggressive behavior of grade II astrocytomas could be predicted by the number and type of gross chromosomal aberrations. We used comparative genomic hybridization to analyze 11 grade II astrocytomas with typical (good, n = 7) or poor (n = 4) prognosis. The results were also compared with a reference material of 13 grade III-IV astrocytomas and nine established cell lines. We found a median of two aberrations (range 0 to 4) in tumors with good prognosis and of 15.5 changes (range 8 to 28) in tumors with poor prognosis. Chromosomal gains were present in both groups, whereas chromosomal losses were frequent in tumors with poor prognosis (median 9.5, range 3 to 14) but rare in tumors with good prognosis (range 0 to 2). All chromosomal gains were also found in the high-grade astrocytoma group and the majority of them in cell lines. Chromosomal losses in grade II astrocytomas with poor prognosis were very similar to those in grade III-IV astrocytomas and cell lines. We conclude that an early accumulation of genetic changes in grade II astrocytomas is closely associated with poor patient prognosis, suggesting diagnostic use for comparative genomic hybridization in characterization of grade II astrocytomas.

Adolescent↗

PubMed1996

Evaluation of camera requirements for comparative genomic hybridization.

Comparative genomic hybridization (CGH) is based on quantitative digital image analysis of fluorescence intensities from metaphase chromosomes. High-quality CCD cameras are commonly used for image acquisition, but the minimal requirements of CCD cameras have not been determined. We first evaluated minimal camera requirements by artificially reducing spatial and dynamic resolution of images produced by a scientific-grade CCD camera (Xillix MicroImager). The results showed that reduction of dynamic resolution from 4,096 to 256 gray levels (12-bit image transformed to an 8-bit image) had negligible effect on CGH profiles and no effect on their interpretation. Similarly, CGH profiles obtained from spatially reduced images (from 1,340 x 1,035 to 670 x 517 pixels) were virtually identical to those obtained from the original image. For a practical test, we compared two 8-bit frame integrating video-rated CCD cameras (Cohu 4910 and Photometrics ImagePoint) to the Xillix Micro-Imager in a real CGH setting. Images collected from the same metaphase cells with all three cameras resulted in the identification of the same genetic changes in the samples studied. We conclude that requirements for camera resolution in CGH analysis are not stringent, and therefore that low-priced video-rated cameras capable of frame integration are sufficient for comparative genomic hybridization.

DNA↗

PubMed1996

Independent amplification and frequent co-amplification of three nonsyntenic regions on the long arm of chromosome 20 in human breast cancer.

DNA amplification at 20q13.2 is common in breast cancer, correlates with poor prognosis, and may reflect location of an important oncogene. Recently, other regions along 20q were also found to undergo amplification. Here, amplification levels and patterns of co-amplification were analyzed by interphase fluorescence in situ hybridization at 14 loci along 20q in 146 uncultured breast carcinomas and 14 cell lines. Three regions were independently amplified in uncultured tumors: RMC20C001 region at 20q13.2 (highly amplified in 9.6% of the cases), PTPN1 region 3 Mb proximal (6.2%), and AIB3 region at 20q11 (6.2%). Co-amplifications involving two or three of these regions were seen in 11 of the 19 highly amplified tumors. The results suggest that three distinct nonsyntenic regions along 20q may be important and that complex chromosomal rearrangements underlie their frequent co-amplification in breast cancer.

Breast Neoplasms↗

PubMed1996

Detection of germline BRCA1 mutations in breast cancer patients by quantitative messenger RNA in situ hybridization.

Mutations in the breast cancer susceptibility gene 1 (BRCA1) may account for one half of all familial breast cancers. Because of the wide spectrum of different germline mutations, identification of BRCA1 mutation carriers using current techniques is laborious and difficult. The majority of the identified mutations, however, lead to aberrant expression of the gene product in tumor tissue, potentially allowing the detection of BRCA1-linked breast cancers using simple histochemical techniques. We performed quantitative mRNA in situ hybridization analysis on archival paraffin-embedded tumor specimens from 25 patients with characterized germline BRCA1 mutations or linkage and from 29 patients with sporadic breast cancers. BRCA1 mRNA levels were invariably low in tumors from BRCA1 mutation carriers. Normal breast epithelium surrounding the BRCA1 tumors showed higher mRNA levels than the tumor tissue, indicating that the low mRNA levels were due to somatic inactivation of the wild-type BRCA1 allele in the tumor tissue. The expression levels in the sporadic tumors were, on average, six times higher than in the BRCA1 tumors (P < 0.0001). The difference allowed identification of BRCA1-mutated and sporadic tumors with more than 95% specificity and sensitivity. We conclude that the analysis of BRCA1 gene expression by mRNA in situ hybridization may be useful in screening for patients with BRCA1-linked breast cancer.

Adult↗

PubMed1996

c-erbB-2 in astrocytomas: infrequent overexpression by immunohistochemistry and absence of gene amplification by fluorescence in situ hybridization.

Recent studies suggest that aberrations of c-erbB-2 may be involved in astrocytic brain tumours. We screened immunohistochemically c-erbB2 protein (p185) expression in 94 astrocytic grade 1-4 neoplasms of the brain. The amplification of the c-erbB-2 oncogene was investigated in protein overexpression cases by dual colour fluorescence in situ hybridisation (FISH). p185 overexpression was correlated with p53 and epidermal growth factor receptor (EGFR) expression, as well as with clinicopathological features. Only two anaplastic (grade 3) astrocytomas and one glioblastoma (grade 4) showed overexpression of p185 protein by immunohistochemistry (monoclonal MAb1 antibody TA250), whereas none of the grade 1-2 astrocytomas was positive. Interestingly, the expression of p185 was confined solely to the cytoplasm of neoplastic astrocytic cells and not to the cell membranes as found in malignancies with amplification of the c-erbB-2 oncogene. Two of the three overexpression cases were also positive by EGFR. No amplification of the c-erbB-2 gene was observed by FISH in the three tumours with immunohistochemical p185 overexpression or seven weakly positive/negative tumours. In conclusion, our results suggest that p185 overexpression is infrequent in astrocytomas, that it is of no important diagnostic or prognostic value and that c-erbB-2 oncogene amplification is not seen in the few cases in which there is overexpression.

Adolescent↗

PubMed1996

Loss of estrogen receptor in recurrent breast cancer is associated with poor response to endocrine therapy.

PURPOSE: Up to 30% to 40% of metastases from hormone receptor-positive primary breast cancer do not respond to endocrine therapy. We studied how often hormone receptor status changes between primary and recurrent tumors and whether such a change might explain unresponsiveness to endocrine therapy. PATIENTS AND METHODS: Primary breast cancer samples and matched asynchronous recurrences were studied from 50 patients who had not received any adjuvant therapy. Estrogen receptor (ER) and progesterone receptor (PR) status was determined immunohistochemically from histologically representative formalin-fixed paraffin-embedded tumor samples. ER status was ascertained by mRNA in situ hybridization. RESULTS: Thirty-five (70%) of 50 primary tumors were positive for ER and 30 (60%) for PR. Hormone receptor status of the recurrent tumor differed from that of the primary tumor in 18 cases (36%). Discordant cases were due to the loss of ER (n = 6), loss of PR (n = 6), or loss of both receptors (n = 6). Receptor-negative primary tumors were always accompanied by receptor-negative recurrences. Among 27 patients with ER-positive primary tumors, loss of ER was a significant predictor (P = .0085) of poor response to subsequent endocrine therapy. Only one of eight patients (12.5%) with lost ER expression responded to tamoxifen therapy, whereas the response rate was 74% (14 of 19) for patients whose recurrent tumors retained ER expression. CONCLUSION: Loss of ER expression in recurrent breast cancer should be considered as a cause for poor response to endocrine therapy in primarily ER-positive patients. We conclude that analysis of recurrent tumor samples may improve the predictive value of ER and PR assays.

Adult↗

PubMed1996

Expression of topoisomerase IIalpha is associated with rapid cell proliferation, aneuploidy, and c-erbB2 overexpression in breast cancer.

The role of molecular markers predicting the response to cytotoxic chemotherapy is not established. A potential predictive factor, topoisomerase IIalpha, is a target for certain cytotoxic drugs, and its concentration has been shown to correlate with chemosensitivity in vitro. We evaluated expression of topo IIalpha immunohistochemically in 230 breast cancer samples and studied its association with known clinicopathological factors and factors previously shown to predict response to cytotoxic drugs. Topo IIalpha protein expression was found in 0.6 to 39.4% (10.6 +/- 7.9%, mean +/- SD) of breast carcinoma cells, whereas expression was undetectable in nonmalignant breast epithelium. Topo IIalpha protein expression correlated well with semi-quantitative mRNA in situ hybridization (P = 0.007). A significant association was found between the proportion of topo-IIalpha-positive cells and low estrogen and progesterone receptor content (P<0.0001), high grade (P<0.0001), DNA aneuploidy (P=0.003), and c-erbB-2 oncoprotein overexpression (P<0.0001). Topo IIalpha expression was not associated with clinical variables, such as age of the patient, primary tumor size, or axillary nodal status. A highly significant linear correlation was found between topo IIalpha and tumor proliferation rate (S-phase fraction, r=0.46; P<0.0001). Because hormone receptors, grade, and ploidy are associated with tumor proliferation rate, topo IIalpha expression was adjusted for S-phase fraction to reveal the proliferation-independent clinopathological associations. According to the analysis of co-variance, only aneuploidy (P=0.0003) and c-erb-2 overexpression (P=0.01) were associated with proliferation-adjusted expression of topo IIalpha. In conclusion, the close association of Topo IIalpha with other potential predictive factors (tumor proliferation rate, c-erbB-2 oncoprotein) suggests that topo IIalpha, having a defined role as a target for cytotoxic drugs, may be a valuable predictor of response to chemotherapy.

Adult↗

PubMed1996

Macrophages contain 92-kd gelatinase (MMP-9) at the site of degenerated internal elastic lamina in temporal arteritis.

Inflammation precedes erosion and rupture of atherosclerotic atheromas and aneurysms. Inflammatory infiltrates of macrophages have been shown to secrete proteolytic enzymes, including matrix metalloproteinases (MMPs), that weaken the arterial wall. The effect of inflammation on arterial structure and remodeling can be studied in primary vascular inflammatory diseases such as in temporal arteritis. We examined the 72-kd gelatinase (MMP-2) and the 92-kd gelatinase (MMP-9) in inflamed and uninvolved temporal arteries from 10 patients with temporal arteritis and 5 controls by immunohistochemistry. The substrates of these enzymes, type IV collagen and elastin, were detected by immunohistochemistry and histochemical staining, respectively. Both diseased and normal artery specimens had moderate staining for immunoreactive MMP-2. Temporal arteritis specimens had clearly enhanced immunostaining for MMP-9 compared with normal arteries. MMP-9 was specifically localized to macrophages in regions of internal elastic lamina disruption, which may thus be of pathological significance.

Aged↗

PubMed1995

Aggressiveness of screen-detected breast cancers.

It is not clear whether screening for breast cancer works as public health policy and whether early indicators of effect predict an ultimate reduction in mortality. The malignant potentials of 248 breast cancers detected by the screening service in Finland were compared with those of 490 control cancers diagnosed before the screening service was established. Aggressiveness was assessed by DNA flow cytometry and clinical status by cancer size and node involvement. After the first screening round, the results of DNA flow cytometry were the same in cancers diagnosed by screening and in controls; these findings are consistent with the hypothesis that the biological aggressiveness of breast cancer remains constant as the cancer progresses. The proportion of patients with node-negative and small T1 cancers after the first screening was higher among the screened population than among controls, indicating earliness of diagnosis among those screened. Cancers diagnosed in the first round had a low malignant potential, as indicated by the DNA flow-cytometry and by clinical stage. Lower aggressiveness of cancers found by screening than of control cancers would indicate overdiagnosis or length-biased sampling, but not earliness of diagnosis. Screening with mammography is practised as a public-health policy in Finland. The results predict that the mortality reduction found in randomised trials can be repeated with a screening service.

Aged↗

PubMed1995

Prognostic effect of timing of operation in relation to menstrual phase of breast cancer patient--fact or fallacy.

The effects of the timing of operation in relation to menstrual phase and hormone receptor protein positivity and concentration of the 5 year survival of 267 premenopausal women with operable breast cancer were evaluated. The patients were treated in the Tampere University Hospital Area in 1980-87, and information about menstrual cycle was recorded before the operation. Patients operated on during the luteal phase (days 15-32) had a trend towards a better survival rate (80.4%) than those treated in the follicular phase (days 1-14) (75.9%), but the difference did not reach statistical significance (P = 0.079). There was a small difference in the positivity and concentration of hormone receptor proteins, depending on the phase of the menstrual cycle. A more sensitive analysis found a statistically significant linear association between survival and day since last menstrual period (LMP) which was not totally accounted for by the variation in hormone receptor levels during the menstrual cycle or other main prognostic factors (P = 0.018 by Cox's multivariate regression analysis when LMP was used as a continuous variable). One possible mechanism for the effect of timing can be that physiological changes related to different phases of menstrual cycle unfavourably affect the quality of diagnostic and/or treatment procedures. Variation in the lag between the diagnostic confirmation and the operation of the patient affects the evaluation of such an effect and may account for the inconsistent results reported so far.

Breast Neoplasms↗

PubMed1995

Stromal cell cathepsin D expression and long-term survival in breast cancer.

Breast cancers with an increased level of cathepsin D in tumour tissue extract have been found to have poor prognosis, but studies performed with immunohistochemistry have produced variable results. We analysed 213 primary invasive breast cancers for cathepsin D expression from archival tissue with immunohistochemistry. The minimum follow-up of the patients still alive was 26 years. Women with ductal cancer that lacked cathepsin D expression in stromal macrophage-like cells had a 75% 5 year and 55% 30 year survival rate as compared with only a 40% 5 year and 20% 30 year survival rate if stromal cells expressed cathepsin D (P = 0.0003), whereas cathepsin D expression of cancer cells was associated with neither survival nor the several prognostic factors investigated. Stromal cell cathepsin D was more often present in the ductal than in the lobular histological type (80% vs 54%, P = 0.002), and its expression was strongly associated particularly with a high cell proliferation rate. However, in a multivariate analysis stromal cell cathepsin D expression did not have independent influence on survival in the entire series. We conclude that high stromal cell cathepsin D expression is associated with a poor short- and long-term outcome in breast cancer.

Adult↗