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S Heim

Publications and source records attributed to S Heim.

At least 73 records · Page 4Linked to original sources
PubMed1998

Cytogenetic heterogeneity in a second primary radiation-induced bladder carcinoma: ten karyotypically unrelated clones.

Cytogenetic analysis of a transitional cell carcinoma (TCC) of the bladder, the tumor having developed 32 years after the patient received pelvic irradiation and interstitial radium implantation for an endometrial carcinoma, revealed the presence of 10 cytogenetically abnormal, unrelated clones. Although the tumor was poorly differentiated, all clones were pseudo- or near-diploid with rather simple balanced or unbalanced structural rearrangements or both. The chromosomes involved in structural changes more than once were chromosomes 8, 9, and 11, which were rearranged in three clones, and chromosomes 3 and 17, both rearranged in two clones. No previous TCC of the bladder with cytogenetically unrelated clones has been reported, nor has any such radiation-induced tumor with chromosomal abnormalities been described. The distinct karyotypic and clonal pattern of the case presented here is probably indicative of a carcinogenic field effect due to the previous pelvic irradiation. Postradiation bladder carcinomas thus seem to be distinct cytogenetically in addition to their known unique etiological and clinical features.

Aged↗
PubMed1998

Cytogenetic comparison of primary tumors and lymph node metastases in breast cancer patients.

Chromosome banding analysis of primary tumors and axillary lymph node metastases from 10 breast cancer patients revealed abnormal karyotypes in all samples with cytogenetic similarities between the primary tumor and the metastasis in all informative pairs. Although karyotypically unrelated clones were also found in the lymph node samples, they were less numerous than in the primary tumors, indicating that there was more genetic heterogeneity among the neoplastic cells in the primary than in the secondary tumors. On the other hand, some of the clones had become more complex in the metastases as a result of clonal evolution, and by and large these metastatic breast cancer cases had more karyotypic anomalies than do unselected primary breast carcinomas. Among the aberrations occurring more frequently, and that consequently may predispose to disease spread, were losses of chromosomes 17 and 22 and homogeneously staining regions, a cytogenetic sign of gene amplification.

Adult↗
PubMed1998

Cytogenetic analysis shows that carcinosarcomas of the breast are of monoclonal origin.

Carcinosarcoma of the breast is a rare biphasic neoplasm composed of a carcinomatous component contiguous or admixed with a pleomorphic spindle cell component. The issues of the histogenesis and clonal composition of carcinosarcomas have long been debated. We present the first cytogenetic characterization of mammary carcinosarcomas by analysis of eight tumor samples from two patients with this disease. In the first case, the same karyotypically complex clone, as well as evidence of clonal evolution, was found in samples from three separate areas of the primary tumor. The analysis of one intramammary and one axillary lymph node metastasis from the same patient, both showing only the sarcomatous tumor component, also revealed the common complex stemline and one of the two sidelines found in the primary tumor. The carcinosarcoma of the second patient contained six complex but karyotypically related clones unevenly distributed among the three samples examined. From this case, cells belonging to the carcinomatous and sarcomatous tumor components were separated by differential sedimentation and culturing in specific growth media. Analysis of both fractions showed largely the same karyotype, although one of the subclones was restricted to the epithelial component. Our findings indicate that the epithelial and mesenchymal components of mammary carcinosarcomas are both part of the neoplastic parenchyma and that they have evolved from a single common stem cell, in agreement with the hypothesis that the tumors are of monoclonal origin.

Breast Neoplasms↗
PubMed1998

Chromosome abnormalities in squamous cell carcinoma of the urethra.

Cytogenetic analysis of short-term cultured cells from a urethral squamous cell carcinoma showed the tumor to have an abnormal, karyotypically complex near-diploid clone as well as its near-tetraploid duplicate. This is the first urethral carcinoma with chromosomal abnormalities to be reported. Chromosomes Y, 2, 3, 4, 6, 7, 8, 11, and 20 were all involved in numerical and/or structural rearrangements. Of particular interest was the fact that no rearrangements of chromosomes 9 and 17, both almost ubiquitously involved in transitional cell carcinoma of the urinary tract, were seen.

Aged↗
PubMed1997

Fluorescence in situ hybridization of old G-banded and mounted chromosome preparations.

An improved method for fluorescence in situ hybridization (FISH) investigation of old, previously G-banded, mounted chromosome preparations with chromosome specific painting probes and centromere-specific probes is described. Before hybridization, the slides are incubated in xylene until the coverslips detach spontaneously; any mechanical manipulation will jeopardize the results. The success of chromosome painting is improved by excluding the regular RNase treatment step prior to hybridization. Additional changes compared with standard FISH protocols are that the 2 x SSC step is omitted, that the amount of added probe is increased approximately 2.5 times, and that the amplification of signals is performed twice. The applicability of the method, which allows double painting with two differently labeled probes using two differently fluorescing colors, was tested on 11 cases involving different chromosome abnormalities and different types of material, including short-term cultures of epithelial and mesenchymal tumors, blood, leukemic bone marrow, and long-term cultures of a cell line derived from an epithelial tumor. Success was achieved even with chromosome preparations that were several years old.

Chromosome Aberrations↗
PubMed1997

Cytogenetic findings in metastases from colorectal cancer.

Eighteen tumor samples from 11 patients with metastatic colorectal cancer were cytogenetically analyzed after short-term culturing. Of the 13 metastases examined, 11 were from lymph nodes, 1 from the peritoneum and 1 from the lung. In 5 of the 11 patients, matched samples from the primary tumor and lymph node metastases were analyzed. Cytogenetic similarities between the primary and secondary lesions were found in all 5 cases, indicating that many of the chromosomal aberrations presumably occurred before disease spreading took place. Compared with the primaries, the metastases appeared to exhibit decreased clonal heterogeneity but, concurrently, an increase in the karyotypic complexity of individual clones. Among the aberrations recurrently found in metastatic lesions were del(1)(p34), i(17)(q10), -18, -Y, -21, +7 and +20, all of which have been seen repeatedly in previous series of primary colorectal carcinomas, and del(10)(q22) and add(16)(p13), which so far have not been associated with primary tumors and which may play a particular pathogenetic role in the metastatic process.

Adenocarcinoma↗
PubMed1997

Cytogenetic analysis of inverted nasal papillomas and demonstration of genetic convergence during in vitro passaging.

Three inverted nasal papillomas were cytogenetically investigated after short-term culture. Two of the cases were characterized by a single abnormal clone with t(1;8)(p36;q11) and trisomy 7, respectively, whereas the third papilloma showed extreme cytogenetic heterogeneity: of 852 analyzed cells, 329 belonged to 36 unrelated clones, 344 had non-clonal changes, and 179 had a normal chromosome constitution. The polyclonal papilloma was further analyzed during in vitro passage of 3 lines (L1-L3) cultured independently since initiation of the primary cultures and found to have 6, 16 and 6 unrelated clones at analysis of primary cultures. At passage 1, each line was further subdivided into 2 sub-lines (L1A and B, L2A and B, and L3A and B), which were cultured separately until the cells spontaneously stopped dividing. After 4 to 7 passages, each sub-line was dominated (83-98% of the cells) by a single clone. The cell populations that took over the cultures were the same within each set of sub-lines (A and B lines), demonstrating that clonal overgrowth in vitro is not random. The difference in clonal selection among the L1-L3 lines further shows that genetic convergence during in vitro growth in stable conditions is dependent not only on the clones' ability to adapt to the culture conditions, but also on the nature of the neighboring cells with which they collaborate and compete.

Aged↗
PubMed1997

Clonal chromosome aberrations accumulate with age in upper aerodigestive tract mucosa.

Short-term cultured non-neoplastic upper aerodigestive tract (UAT) mucosa samples from 36 patients with squamous cell carcinoma of the head and neck (SCC) and 53 patients with benign UAT disorders were cytogenetically analyzed. The cell cultures were divided into two series: in series A, cells were cultured in a medium stimulating outgrowth of mesenchymal cells; whereas the cultured cells in series B were of epithelial morphology. Series A was further subdivided into three different age groups (< or = 15 years, 16-59 years, and > or = 60 years) of non-SCC patients and one SCC group. Series B was composed of two groups; one with and one without SCC. Among the non-SCC patients in series A, there was an increase with age in the frequency of cells/sample with numerical and structural chromosomal changes as well as in the incidence of clonal chromosomal aberrations. No differences could, however, be detected between cancer patients and age-matched controls. In series B, the frequency of cells/sample with numerical changes and the incidence of clonal numerical aberrations were significantly higher among SCC patients. Three main conclusions could be drawn. First, the frequencies of clonal and non-clonal chromosome aberrations in UAT mucosa were age dependent. Second, the cytogenetic support for the validity of the field cancerization hypothesis was restricted to increased levels of numerical chromosome changes in epithelial cell cultures from cancer patients. Third, clonal chromosome aberrations, including autosomal and sex chromosome aneuploidies as well as structural rearrangements, are not restricted to neoplastic mucosal cells.

Adolescent↗
PubMed1997

Heterodisulfide reductase from methanol-grown cells of Methanosarcina barkeri is not a flavoenzyme.

Heterodisulfide reductase from methanol-grown cells of Methanosarcina barkeri (MbHdrDE) is a membrane-bound enzyme composed of a 46-kDa subunit MbHdrD and a 23-kDa subunit MbHdrE. The enzyme has been shown to contain 0.6 mol heme and 20 mol Fe/S per mol heterodimer. In addition, substoichiometric amounts of FAD, thought to be an essential component of the active enzyme, were detected. We have now obtained preparations of active heterodisulfide reductase in high yields completely devoid of a flavin. Cloning and sequencing of the genes encoding MbHdrD and MbHdrE, which were found to form a transcription unit hdrED, revealed that both subunits also lack an FAD-binding motif. MbHdr thus differs from heterodisulifde reductase from Methanobacterium thermoautotrophicum (MtHdr), which is a flavo iron-sulfur protein composed of the subunits MtHdrA (80 kDa), MtHdrB (36 kDa) and MtHdrC (21 kDa), the subunit HdrA harboring the flavin-binding site. Sequence comparisons revealed that the N-terminal third of MbHdrD, which contained two sequence motifs for [4Fe-4S] clusters, is similar to MtHdrC and that the C-terminal two thirds of MbHdrD are similar to MtHdrB. Thus, MbHdrD and MtHdrC are structurally equivalent subunits. MbHdrE shows sequence similarity to b-type cytochromes, in agreement with the finding that this subunit contains a heme. These and other results indicate that MbHdrD harbors the active site of heterodisulfide reduction and that a flavin is not involved in catalysis. Since MbHdrD contains only iron-sulfur clusters, a mechanism of disulfide reduction involving one electron rather than two electron-transfer reactions has to be considered such as operative in ferredoxin :thioredoxin reductases from chloroplasts and cyanobacteria.

Amino Acid Sequence↗
PubMed1997

The reciprocal translocation t(9;16)(q22;p13) is a primary chromosome abnormality in basal cell carcinomas.

The reciprocal translocation t(9;16)(q22;p13) was identified in three short-term cultured basal cell carcinomas (BCCs). The t(9;16) was the sole anomaly in one clone in two tumors and was accompanied by a second change that also affected the long arm of chromosome 9 in the third. In addition, other cytogenetically unrelated abnormal clones were also found in all three BCCs. The identification of t(9;16)(q22;p13) as a primary chromosomal abnormality in a subset of BCCs (we found it in 3 of 22 tumors) is especially intriguing against the background that the PTCH gene, which when mutated in the germ line presumably gives rise to the autosomal dominant basal cell nevus or Gorlin's syndrome, maps to chromosome band 9q22. None of the genes rearranged in the BCC-specific t(9;16)(q22;p13) translocation have been identified, but we hypothesize that the translocation represents the cytogenetic corollary of a tumorigenic recombination of PTCH with an as yet unknown gene in 16p13. If so, this would be the first time that a tumor suppressor gene causally involved in a hereditary cancer is shown to be frequently rearranged through a specific translocation in sporadic carcinomas of the same type.

Aged↗
PubMed1997

Karyotypic abnormalities in fibroadenomas of the breast.

Short-term cultures of 50 fibroadenomas of the breast were cytogenetically analyzed. Nine tumors were found to display clonal chromosome aberrations. One had multiple, cytogenetically unrelated clones, whereas the others had a single abnormal clone each. Four cases had one balanced translocation as the sole anomaly, and one had a complex intrachromosomal rearrangement of chromosome 3, leading to loss of 3p material. One fibroadenoma had a single numerical aberration, and one had supernumerary ring chromosomes. The remaining 2 cases had both numerical and structural aberrations. The only recurrent alterations were trisomy 20 and rearrangement of chromosome arm 1p. The finding of similar chromosomal aberrations in fibroadenomas and carcinomas suggests that women with karyotypically abnormal fibroadenomas may have an increased risk of developing subsequent breast cancer. If so, different chromosome anomalies might have different pathogenetic and/or prognostic significance.

Adolescent↗
PubMed1997

Discrimination between multicentric and multifocal breast carcinoma by cytogenetic investigation of macroscopically distinct ipsilateral lesions.

Whether macroscopically distinct carcinomas in the same breast are clonally related (multifocal breast carcinoma) or unrelated (multicentric breast carcinoma) is no longer only a scientific-pathological issue but, because different therapeutic strategies may be preferable for cases with intramammary metastatic disease compared with cases of multiple primary breast carcinomas, one that may have profound clinical implications. We studied the evolutionary relationship among macroscopically distinct, ipsilateral breast carcinomas by cytogenetic analysis of 26 tumorous lesions from 12 patients. Sixteen of the 26 foci (62%) were found to contain clonal chromosome abnormalities. Two carcinoma foci were karyotypically abnormal in each of seven patients. Four of these cases had an evolutionarily related, cytogenetically abnormal clone in the two lesions from the same breast, whereas the remaining three cases had completely different clonal karyotypic aberrations in the separate foci. These results, together with our previous findings in five other informative cases, show that multiple, synchronous breast tumors sometimes arise through intramammary spreading of a single primary carcinoma, whereas on other occasions they are the result of the simultaneous emergence of pathogenetically independent carcinomas within the breast. In the total material, an association was seen between the proximity of the foci and the likelihood of them being karyotypically related.

Breast Neoplasms↗
PubMed1997

Cytogenetic findings in phyllodes tumors of the breast: karyotypic complexity differentiates between malignant and benign tumors.

Clonal karyotypic abnormalities were detected in short-term cell cultures from six phyllodes tumors of the breast. Whereas all five benign tumors had simple chromosomal changes, the highly malignant one had a near-triploid stemline, indicating that karyotypic complexity is a marker of malignancy in phyllodes tumors. Interstitial deletions of the short arm of chromosome 3, del(3)(p12p14) and del(3)(p21p23),were the only aberrations in two benign tumors. Cytogenetic polyclonality was detected in three benign tumors: two had cytogenetically unrelated clones, whereas the third had three different, karyotypically related cell populations as evidence of clonal evolution. The finding of clonal chromosome abnormalities in both the epithelial and connective tissue components of the phyllodes tumors indicates that they are genuinely biphasic, that is, that both components are part of the neoplastic parenchyma.

Breast Neoplasms↗
PubMed1997

Cytogenetic analysis of several pseudomyxoma peritonei lesions originating from a mucinous cystadenoma of the appendix.

Epithelial proliferative lesions of the appendix are rare and have never been studied cytogenetically. We present the chromosomal banding analysis of four successfully short-term cultured samples from pseudomyxoma peritonei lesions originating from a cystadenoma of the appendix. All four sample contained clonal chromosome abnormalities. In three of them, the clone 46,XX,der(6)?del(6)(q16q21)?del(6)(q27) was found, whereas a clone with the karyotype 46,XX,t(2;17)(p21;p13),t(6;12)(p21;q13),t(12;15)(q24;q15) was detected in the fourth sample. Our findings support the view that pseudomyxoma peritonei originates by spreading from a primary mucinous neoplasm of an intraperitoneal organ rather than through mucinous metaplasia or multifocal primary neoplastic transformation of the peritoneum.

Adult↗
PubMed1997

Cytogenetic polyclonality in tumors of the breast.

Cytogenetically unrelated clones are found in half of all carcinomas of the breast and also in the epithelial fraction of many benign breast tumors. The chromosomal aberrations thus detected are clearly nonrandom and appear to be the same as those often seen in other tumors as sole karyotypic anomalies. Clonal chromosome abnormalities are not found in histologically normal breast tissue. Cytogenetically unrelated clones may be found in both primary tumors and secondary lesions, be it within the same breast (multifocal carcinomas), in the contralateral breast (bilateral carcinomas), or in lymph node or other metastases. The aberrations are present in topologically separate tumor domains and may confer on the cells that harbor them different types of cancer-specific behavior, such as the ability to metastasize and invade locally. Whereas the available evidence thus strongly indicates that the cells carrying clonal karyotypic aberrations all are part of the neoplastic parenchyma, it is less certain whether cytogenetic polyclonality actually signifies a multicellular tumor origin, although we think that this is the explanation that best accommodates the cytogenetic data. But even if it should eventually be shown that the seemingly unrelated clones have some submicroscopic tumorigenic mutation in common, the observed karyotypic heterogeneity is remarkable and goes far beyond what one has become accustomed to from most other tumor types. To understand how the various clones interact during mammary carcinogenesis will be a major task in future breast cancer research.

Breast Neoplasms↗
PubMed1997

A subgroup of breast carcinomas is cytogenetically characterized by trisomy 12.

Chromosome analysis of short-term cultured breast carcinoma cells revealed trisomy 12 in four cases. In one tumor it was the only abnormality. The second case showed cytogenetic polyclonality, but the mainline had +12 as the sole change. In the remaining two tumors, trisomy 12 was part of more complex karyotypes. These findings, especially when coupled with similar information on previously published cases, show that gain of chromosome 12 is a recurrent and sometimes early event in breast carcinogenesis.

Aged↗
PubMed1997

Cytogenetic comparisons of synchronous carcinomas and polyps in patients with colorectal cancer.

Thirty tumorous lesions from seven patients with colorectal cancer were short-term cultured and cytogenetically analysed: 16 non-adenomatous polyps, six adenomas, seven carcinomas, including one in polyp, and one lymph node metastasis. Clonal chromosome aberrations were found in 20 samples in 100% of the carcinomas, in 100% of the adenomas and in 37.5% of the non-adenomatous polyps, i.e. all ten lesions with a normal karyotype were histologically diagnosed as hyperplastic polyps. Although adenomas and carcinomas shared several karyotypic features, two chromosome aberrations, der(8;17)(q10;q10) and -14, were found in carcinomas but not in adenomas, indicating that they might be specifically associated with carcinoma development in the large bowel mucosa. The karyotypic similarity seen between the malignant and benign tumours in the same patient, and also sometimes among non-malignant polyps in the same case, indicates that these microscopically distinct lesions may be part of a single neoplastic clonal expansion.

Adenoma↗