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Biomedical subjects

F Mitelman

Publications and source records attributed to F Mitelman.

At least 91 records · Page 5Linked to original sources

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↗

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↗

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↗

Additional evidence of a variant translocation t(12;22) with EWS/CHOP fusion in myxoid liposarcoma: clinicopathological features.

It is well established that the majority of myxoid/round cell liposarcomas (LPS) are characterized by a reciprocal translocation t(12;16)(q13;p11) which at the molecular level results infusion of the CHOP and FUS/TLS genes. It is assumed that functional characterization of these genes may provide insight into the molecular pathogenesis of this tumour type. This study describes two new cases of myxoid/round cell LPS having a t(12;22). By reverse transcription-polymerase chain reaction (RT-PCR) it has been shown that this leads to fusion between the CHOP and EWS genes, thus indicating involvement of the EWS gene, at least occasionally, in yet another sarcoma type. Combining these two cases with two others which were recently similarly characterized at the molecular level, their clinicopathological features have been compared with cases having the more usual t(12;16). It was not possible to identify any clinical or pathological differences between these molecular genetic subsets. The relevance or significance of these gene fusion products in myxoid/round cell LPS remains to be determined.

Adult↗

Deletions of CDKN1B and ETV6 in acute myeloid leukemia and myelodysplastic syndromes without cytogenetic evidence of 12p abnormalities.

Seventy-nine acute myeloid leukemias (AML) and myelodysplastic syndromes without cytogenetic evidence of 12p aberrations were investigated by fluorescence in situ hybridization with probes for ETV6 and CDKN1B (previously called TEL and KIP1, respectively) to ascertain whether abnormalities of these genes are frequently undetected by standard chromosome banding analyses and, if so, whether they are associated with specific karyotypic patterns and morphologic features. One of sixty cytogenetically aberrant myeloid malignancies, an AML with a complex karyotype including del(5q) and del(20q), showed a hemizygous interstitial deletion of the ETV6 and CDKN1B loci. No concomitant rearrangement of the other ETV6 allele was detected. Two of nineteen cytogenetically normal AML displayed a hemizygous interstitial deletion involving CDKN1B, but not ETV6. Thus, cryptic deletions of these genes seem to be rare in cytogenetically abnormal myeloid malignancies without 12p aberrations (2%), whereas they may be more frequent in karyotypically normal AML (10%). Furthermore, the present findings show that the deletions may be narrow, not including the ETV6 gene, and indirectly suggest that CDKN1B, or a closely located genomic segment, is the target of 12p deletions.

Acute Disease↗

Variable FHIT transcripts in non-neoplastic tissues.

We used nested reverse transcriptase PCR to investigate the expression of the FHIT gene, a presumptive tumor suppressor gene located in chromosomal band 3p 14.2, in non-neoplastic samples. Multiple transcripts of the FHIT gene were found in peripheral blood lymphocytes, skeletal muscle, and liver of healthy individuals, as well as in a cell line derived from isynovial tissue. The data indicate that variable splicing of the FHIT transcript, leading to deletions of exons and thus anomalous or absent FHIT protein production, occurs frequently in non-neoplastic tissues. Hence, the finding of multiple nonfunctional FHIT transcripts is not tumor-specific and cannot be used as a genetic marker of neoplasia.

Acid Anhydride Hydrolases↗

Clonal CD5-positive B lymphocytes in myelodysplastic syndrome with systemic vasculitis and trisomy 8.

Bone marrow and peripheral blood from a myelodysplastic syndrome (MDS) patient with trisomy 8 and associated systemic vasculitis was investigated for clonal lymphoid lineage involvement using simultaneous metaphase and interphase fluorescence in situ hybridization (FISH) and immunocytochemistry with antibodies against CD13 (granulocytic), glycophorin A (GPA, erythroid), and the lymphocytic antigens CD3. CD5, CD20, and CD22. Trisomy 8 was detected in 55% of CD13+, 40% of GPA+, 6% of CD5+, and 5% of CD20/22+, but not in CD3+ cells. In a complementary experiment using interphase FISH on bone marrow cells sorted by flow cytometry, 13% of CD5/CD19 double-positive cells (76% purity) were found to be trisomic. The results indicate the existence of a small CD5-positive B-lymphoid clone as part of the MDS process in this patient. Since CD5/19-positive cells have been proposed to be autoantibody producing, this finding might be a clue to the pathogenesis underlying the propensity for MDS patients to develop immune-mediated complications.

B-Lymphocytes↗

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↗

Clinical significance of cytogenetic findings in solid tumors.

Chromosome analysis of solid tumors is becoming an increasingly useful tool to help establish a correct diagnosis and to provide prognostically important information. Characteristic karyotypic patterns in terms of degree of cytogenetic complexity and type of nonrandom abnormalities may help to distinguish neoplasia from a nonneoplastic lesion and to differentiate between a benign and a malignant tumor. More importantly, the presence of a specific or pathognomonic change may confirm or refute a suspected diagnosis, provide an alternative, unsuspected diagnosis, and trace the origin of a metastasis. Presently, specific cytogenetic abnormalities may be of substantial, and sometimes decisive, help in four groups of differential diagnostic dilemmas: (1) Benign vs. malignant epithelial tumors of the kidney, thyroid gland, salivary glands, and ovary; (2) Benign vs. malignant mesenchymal tumors of adipose and muscle tissue; (3) Differentiation between various malignant bone and soft tissue tumors: and (4) Diagnosis of undifferentiated small-cell round-cell tumors. In addition to the diagnostic value, karyotypic findings may provide prognostic information. Thus, the presence of an abnormal clone and/or complex rearrangements is a poor prognostic sign in, e.g., carcinomas of the ovary, prostate, bladder, colon, and pancreas. Furthermore, characteristic cytogenetic aberrations are now known to be valuable prognostic parameters in malignant melanoma, malignant fibrous histiocytoma, germ cell tumors, neuroblastoma, and squamous cell carcinoma of the head and neck region. Many of the correlation analyses are preliminary, but they all point in the same direction, namely that cytogenetic studies will soon play the same essential role in the management of patients with solid tumors as they do today in hematologic oncology.

Chromosome Aberrations↗

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↗

Translocations between the long arms of chromosomes 1 and 5 in hematologic malignancies are strongly associated with neoplasms of the myeloid lineages.

The clinical, morphologic, and cytogenetic features of two hematologic malignancies--one acute myeloid leukemia with minimal differentiation (AML-MO) and one therapy-related myelodysplastic syndrome (MDS)--with unbalanced translocations between 1q and 5q are reported. The translocations resulted in loss of 5q material in both cases and gain of 1q in the MDS. A compilation of previously published hematologic malignancies with translocations involving the long arms of chromosomes 1 and 5 revealed a total of 23 cases--11 with unbalanced and 12 with balanced t(1;5)--with the following morphologies: 11 AML, three MDS, two Philadelphia-positive chronic myeloid leukemias, three chronic myeloproliferative disorders, three acute lymphoblastic leukemias, and one chronic lymphocytic leukemia. Four patients had received chemotherapy including alkylating agents for a previous malignancy and one had been exposed to thorotrast. Among the 14 patients for whom survival data exist, all except three have died. The t(1;5) was found as the sole abnormality in six cases, whereas it was apparently secondary--occurring in a subclone or together with the well-known primary abnormalities t(8;21), t(9;22), and t(15;17)--in nine cases. The breakpoints in 1q varied from 1q11 to 1q43, with a clustering to 1q21-23, and the 5q breaks occurred in 5q11 to 5q35, mainly in the distal 5q3 region. The unbalanced 1;5 translocations resulted in gain of 1q material in eight of the 11 cases, 1q21-1qter being duplicated in four of them, and in loss of 5q, most often the 5q3 region, in 10 of the neoplasms. We conclude that translocations between 1q and 5q, although cytogenetically heterogeneous, are associated with hematologic malignancies of the myeloid lineages and with previous mutagenic exposure, and that t(1;5) seems to confer a poor prognosis.

Antineoplastic Combined Chemotherapy Protocols↗

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↗

A breakpoint map of recurrent chromosomal rearrangements in human neoplasia.

Cytogenetic studies over the past few decades have revealed clonal chromosomal aberrations in almost 27,000 human neoplasms. Many of these neoplasia-associated chromosomal abnormalities have been characterised at the molecular level, revealing previously unknown genes that are closely associated with the tumorigenic process. Information on chromosome changes in neoplasia is growing rapidly, making it difficult to identify all recurrent chromosomal aberrations. We have developed a computer program to ascertain, for the first time, all recurrent structural abnormalities in all haematological malignancies and solid tumours published up to June 1996. Out of 26,523 cases, a total of 215 balanced and 1,588 unbalanced recurrent aberrations were identified among 75 different neoplastic disorders. Our compilation of all recurrent balanced and unbalanced neoplasia-associated rearrangements should help in directing future efforts aimed at identifying the molecular mechanisms involved in tumorigenesis.

Chromosome Aberrations↗

Deletion of chromosome arm 3p in hematologic malignancies.

Cytogenetic aberrations resulting in deletion of 3p are common in solid tumors, indicating the presence of tumor suppressor genes (TSG) on this chromosome arm. The present study was undertaken to investigate 3p loss in hematologic disorders. Ten acute myeloid leukemias (AML), two myelodysplastic syndromes (MDS), one Philadelphia chromosome-positive chronic myeloid leukemia (CML), three acute lymphoblastic leukemias (ALL), one chronic lymphoproliferative disorder (CLD), and three non-Hodgkin's lymphomas (NHL) with abnormalities leading to 3p deletions were identified, constituting 2.9% of AML, 0.7% of MDS, 1.0% of CML with changes in addition to t(9;22), 1.5% of ALL, 4.2% of CLD, and 1.1% of NHL with cytogenetic abnormalities analyzed at our Department. Among 19042 karyotypically aberrant published cases, 1.2% of 6260 AML, 1.3% of 2285 MDS, 0.8% of 840 chronic myeloproliferative disorders (CMD), 0.7% of 1894 CML with additional aberrations to t(9;22), 0.6% of 3589 ALL 2.4% of 1602 CLD, 4.5% of 178 Hodgkin disease (HD), and 3.1% of 2394 NHL displayed partial loss of 3p (0.6-4.5%; P < 0.001); the majority occurring together with other abnormalities. The frequencies of 3p loss did not differ significantly among the MDS, ALL, and CLD morphologic subgroups, between B and T cell ALL, CLD, and NHL, among low-, intermediate-, and high-grade NHL, or between therapy-related MDS and de novo MDS, whereas the incidence of 3p deletions was higher in treatment-associated AML (P < 0.001) than in de novo AML and varied among the AML FAB groups (P < 0.001). The most frequently deleted chromosome bands were 3p25 in AML, 3p26 in MDS, 3p14 in CMD, 3p25, 3p23, and 3p21 in CML, 3p26 and 3p25 in ALL, 3p26 and 3p25 in CLD, 3p26 in HD, and 3p26 in NHL. These deletion hot spots are more distal than those reported in most solid tumor types, suggesting that different TSG are involved in hematologic malignancies and solid neoplasms.

Chromosome Aberrations↗

Characteristic sequence motifs at the breakpoints of the hybrid genes FUS/CHOP, EWS/CHOP and FUS/ERG in myxoid liposarcoma and acute myeloid leukemia.

We have sequenced the breakpoint regions in one acute myeloid leukemia (AML) with t(16;21)(p11;q22) resulting in the formation of a FUS/ERG hybrid gene and in four myxoid liposarcomas (MLS), three of which had the translocation t(12;16) (q13;p11) and a FUS/CHOP fusion gene and one with t(12;22;20)(q13;q12;q11) and an EWS/CHOP hybrid gene. The breakpoints were localized to intron 7 of FUS, intron 1 of CHOP, an intronic sequence of ERG and intron 7 of EWS. In two MLS cases with t(12;16) and in the AML, the breaks in intron 7 of FUS had occurred close to each other, a few nucleotides downstream from a TG dinucleotide repeat region. The break in the two MLS had occurred in the same ATGGTG hexamer and in the AML 40 nucleotides upstream from the hexamer. The third case of t(12;16) MLS had a break upstream and near a TC-dinucleotide repeat region and a sequence similar to the chi bacterial recombination element was found to flank the breakpoint. In the MLS with the EWS/ CHOP hybrid gene, the break in intron 7 of EWS had occurred close to an Alu sequence. Similarly, in all 4 MLS, the breaks in intron 1 of CHOP were near an Alu sequence. No Alu or other repetitive sequences were found 250 bp upstream or downstream from the break in the ERG intron involved in the AML case. In the AML, the MLS with ESW/CHOP and in one MLS with FUS/CHOP there were one, two and six, respectively, nucleotide identity between the contributing germline sequences in the breakpoint. In the other two MLS cases, two and three extra nucleotides of unknown origin were inserted between the FUS and CHOP sequences. At the junction and/or in its close vicinity, identical oligomers, frequently containing a trinucleotide TGG, were found in both partner genes. Our data thus show that all four genes-FUS, EWS, CHOP and ERG-contain characteristic motifs in the breakpoint regions which may serve as specific recognition sites for DNA-binding proteins and have functional importance in the recombination events taking place between the chromosomes. Different sequence motifs may, however, play a role in each individual case.

Acute Disease↗

Childhood acute lymphoblastic leukaemia with ider(21)(q10)t(12;21)(p12;q22): a new recurrent abnormality showing ETV6/CBFA2 fusion.

The cytogenetically unidentifiable t(12;21)(p12:q22), resulting in ETV6/CBFA2 fusion, is the most frequent chromosomal aberration in childhood acute lymphoblastic leukaemia ALL). We report a variant, ider(21)(q10)t(12:21)(p12;q22), which was shown to contain double ETV6/CBFA2 fusions by fluorescence in situ hybridization. This is the second case of such an ider(21) in childhood ALL, suggesting that it is a new recurrent abnormality. Since the ider(21) is cytogenetically indistinguishable from i(21)(q10) and idic(21)(p11), changes associated with similar clinical features as the t(12;21), i.e. pre-B-cell ALL and age 1-10 years, we suggest that all ALL displaying these changes should be tested for ETV6/CBFA2 fusion transcript.

Child↗

Prognostic implications of cytogenetic findings in kidney cancer.

OBJECTIVE: To evaluate the prognostic impact of cytogenetic findings in renal cell carcinoma (RCC). PATIENTS AND METHODS: Tumour cytogenetics, histomorphology, DNA ploidy and S-phase fraction, stage, size, and grade were related to survival in 50 consecutive patients with RCC. The mean follow-up was 3.9 years (median 4.2, range 0-8.8). RESULTS: The predictive probability for recurrence-free survival at 5 years (5-year RFS) for all 50 patients was 0.54. There was a significant association between the degree of cytogenetic complexity and survival, in that patients with five or less aberrations had a better prognosis than those with more than five changes (5-year RFS 0.71 and 0.43, respectively; P < 0.05). Patients with del(8p)/-8, +12, and +20 had a significantly worse prognosis compared with those without these aberrations. Of the well-known prognostic variables grade and stage, the former was far better for predicting prognosis. A Spearman correlation test showed a significant covariation of grade with the S-phase fraction, T-stage, and cytogenetic complexity. CONCLUSION: The degree of cytogenetic complexity and recurrent cytogenetic abnormalities affect the prognosis in RCC, although grade was the most reliable independent prognostic factor predicting disease recurrence.

Carcinoma, Renal Cell↗