Avery A. Sandberg

Rearrangement of the MLL Gene in Acute Lymphoblastic and Acute Myeloid Leukemias with 11q23 Chromosomal Translocations

BACKGROUND Translocations involving chromosome band 11q23 are very frequent in both acute lymphoblastic and acute myeloid leukemias and are the most common genetic alteration in infants with leukemia. In all age groups and all phenotypes of leukemia, an 11q23 translocation carries a poor prognosis. A major question has been whether one or several genes on band 11q23 are implicated in these leukemias. Previously, we identified the chromosomal breakpoint region in leukemias with the common 11q23 translocations and subsequently cloned a gene named MLL that spans the 11q23 breakpoint. METHODS We isolated a 0.74-kb BamHI fragment from a complementary DAN (cDNA) clone of the MLL gene. To determine the incidence of MLL rearrangements in patients with 11q23 abnormalities, we analyzed DNA from 61 patients with acute leukemia, 3 cell lines derived from such patients, and 20 patients with non-Hodgkins lymphoma and 11q23 aberrations. RESULTS The 0.74-kb cDNA probe detected DNA rearrangements in the MLL gene in 58 of the patients with leukemia, in the 3 cell lines, and in 3 of the patients with lymphoma. All the breaks occurred in an 8.3-kb breakpoint cluster region within the MLL gene. The probe identified DNA rearrangements in all 48 patients with the five common 11q23 translocations involving chromosomes 4, 6, 9, and 19, as well as in 16 patients with uncommon 11q23 aberrations. Twenty-one different chromosomal breakpoints involving the MLL gene were detected. CONCLUSIONS MLL gene rearrangements were detected with a single probe and a single restriction-enzyme digest in all DNA samples from patients with the common 11q23 translocations as well as in 16 patients or cell lines with other 11q23 anomalies. The ability to detect an MLL gene rearrangement rapidly and reliably, especially in patients with limited material for cytogenetic analysis, should make it possible to identify patients who have a poor prognosis and therefore require aggressive chemotherapy or marrow transplantation.

Hereditary nonpolyposis colorectal cancer (Lynch syndromes I and II). I. Clinical description of resource.

Hereditary nonpolyposis colorectal cancer (HNPCC) is comprised of the following: (1) the cancer family syndrome (CFS), or Lynch syndrome II, which shows early‐onset proximal colonic cancer predominance and other associated extracolonic adenocarcinomas, particularly endometrial carcinoma; and (2) hereditary site‐specific colon cancer (HSSCC), or Lynch syndrome I, which shows all of the same characteristics, except for extracolonic cancer. Nine families with CFS and two with HSSCC provided the resource that was tested for biomarkers (see companion article). All families were meticulously evaluated for genealogy and cancer verification. Biologic specimens were obtained during field visits to areas of closest geographic proximity to the families. Cancer education and recommendations for surveillance/management were provided to patients and their physicians. Additionally, 40 families (about 3000 individuals) with either CFS or HSSCC have been ascertained. Syndrome cancers were restricted to direct‐line relatives as opposed to nonbloodline relatives, arguing against involvement of environmntal factors. One documented clinical feature was a predilection for proximal versus distal colonic cancer in both CFS and HSSCC kindreds. This has important clinical significance in that it clarifies the need for instituting effective surveillance earlier to detect the predominantly proximal colonic cancers.

TRANSCORTIN: A CORTICOSTEROID-BINDING PROTEIN OF PLASMA. II. LEVELS IN VARIOUS CONDITIONS AND THE EFFECTS OF ESTROGENS *

Evidence for the existence in human plasma of a protein with high affinity for the binding of corticosteroids, which we have named transcortin, has been recently published from several laboratories (1-5). Even though the concentration of transcortin is considerably lower than that of albumin, the former binds cortisol approximately 6,000 times as strongly as does the latter (5). Therefore, under physiological conditions most of the plasma cortisol has been shown to be bound to transcortin. Transcortin appears to be saturated at plasma levels of cortisol of approximately 30 to 40 ug. per cent (4-5). Some of the characteristics of the corticosteroid-binding protein have been described by Daughaday (2, 6), Bush (3), Upton and Bondy (4) and ourselves (5). In a previous paper we reported a method for measuring the binding capacity of transcortin in plasma and showed it to be increased in the plasma of pregnant women (5). Since the concentration of transcortin may play an important role in the metabolism and biological effects of cortisol, it appeared worthwhile to ascertain the transcortin capacity in several clinical states. Data are presented in this paper on the transcortin binding capacity in the plasma of newborn infants and their mothers; in normal children of various ages; in patients with cirrhosis of the liver; in patients with miscellaneous diseases; and following the administration of estrogenic substances.

Cytogenetic studies of adipose tissue tumors. II. Recurrent reciprocal translocation t(12;16)(q13;p11) in myxoid liposarcomas

Detailed chromosome studies, briefly reported previously, from short-term cultures of tumor cells from myxoid liposarcomas are reported. A common reciprocal translocation, t(12;16)(q13;p11), was found in three cases and a complex t(1;12;16)(p11;q13;p11) in the fourth one. This nonrandom primary change, not described before in solid tumors, could characterize the myxoid form of liposarcoma. The involvement of a closely located breakpoint on chromosome #12 in a reciprocal t(3;12)(q28;q14) described in a lipoma in the previous article of this series, suggests a common basis in the biological process of proliferation of tumors sharing a common histogenesis.

Convention on nomenclature for DNA cytometry

Abstract The Committee on Nomenclature of the Society for Analytical Cytology presents guidelines for the analysis of DNA content by cytometry. These guidelines cover staining of DNA, cytogenetic and cytometric terminology, DNA index, resolution of measurements, and cytometric standards.

Chromosomes and causation of human cancer and leukemia. XXVI. Banding studies in acute lymphoblastic leukemia (ALL)

Chromosomes were studied in the bone marrow cells of 101 patients with acute lymphoblastic leukemia (ALL) hospitalized at or attending the clinics of Roswell Park Memorial Institute (RPMI) between January, 1968, and December, 1976. Aneuploidy was observed in about 50% (54/101) of the cases. Two cases were hypodiploid and the remaining were either pseudo or hyperdiploid. The frequency of abnormalities and the chromosomal numbers were similar to those of 106 cases studied in our laboratory prior to 1968. Of 50 recently unselected cases of ALL in whom Q‐ and G‐banded karyotypes were attempted, 31 were successfully analyzed with these techniques. The banding patterns revealed 16 cases to have chromosome abnormalities and four of these to have a similar abnormality, i.e., partial deletion of the long arm of chromosome #6: two cases had a 6q‐ with additional abnormalities and two had 6q‐ as the sole karyotypic abnormality. The breakpoint in chromosome #6 seemed to involve a segment from q21 to q25. An isochromosome of the long arm of #7, i(7q), was observed in two cases, two additional #21 chromosomes were observed in five cases and, except for the Y, all other chromosomes participated in the karyotypic changes encountered in the 16 cases in which banding analyses were performed. Banding analysis has afforded the first reliable approach towards ascertaining karyotypic evolution in ALL, which was achieved in eight cases of the present study. The chromosomes contributing to this karyotypic evolution were distributed widely. Thus, all chromosomes except the Y participated in numerical and/or structural karyotypic changes. Even though nonrandom chromosome changes may occur early in ALL, the pristine prototypic picture of the karyotypes in ALL is often obfuscated by successive chromosomal changes and hyperdiploidy by the time the karyotypes are analyzed in this condition. Further cytogenetic studies are required, with special attention to karyotypic evolution, in order to uncover the significance of chromosomal changes in early and late ALL.

Prognostic Importance of Cytogenetic Abnormalities in Patients with Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia is recognized as having a variable prognosis, but its staging has depended exclusively on anatomical sites of involvement and the presence or absence of anemia and thrombocytopenia. The recent availability of techniques permitting cytogenetic analysis of malignant B lymphocytes led us to examine the karyotypic abnormalities in chronic lymphocytic leukemia and to correlate them with clinical stage, progression of disease, and survival. Of 53 patients with metaphases adequate for study who were followed for a minimum of one year, 21 (40 per cent) had abnormal karyotypes, of which trisomy 12 was the most frequent (25 per cent). Abnormal karyotypes were found to be significant correlates of advanced clinical stage (P less than 0.005) and of shortened survival (P less than 0.05). We conclude that cytogenetic analysis provides useful clinical and prognostic information in patients with chronic lymphocytic leukemia.

The cytogenetics of solid tumors. Relation to diagnosis, classification and pathology

This overview discusses the chromosome changes in solid tumors and how recent advancements in techniques have yielded results which at least qualitatively are similar to those obtained in the leukemias, i.e., that consistent and recurrent chromosome changes characterize most tumors adequately examined and that tumor entities consist of cytogenetically defined and unique subsets. Thus, the findings point to a similar application of the chromosome changes in tumors in their classification, diagnosis and causation.

Characterization of a New Primary Human Pancreatic Tumor Line

A primary human pancreatic tumor line (BxPC-3) has been established from a biopsy specimen of a histologically confirmed adenocarcinoma of the body of the pancreas. Tumorigenicity was proven by xenograft in athymic nude mice. Upon re-establishment of tumor xenografts in tissue culture, the epithelial tumor cells retained their original morphology. Histopathologically, the tumors grown in nude mice exhibited the original characteristics of the primary adenocarcinoma in the patient, producing traceable mucin and displaying moderately well to poorly differentiated adenocarcinomas with occasional lymphocytic infiltrations at the tumor peripheries. Furthermore, the tumor xenografts differentially expressed carcinoembryonic antigen, human pancreas cancer-associated antigen, and human pancreas-specific antigen. Karyotyping and glucose-6-phosphate dehydrogenase isoenzyme characterization revealed that this tumor line was of human origin and devoid of HeLa cell contamination. The BxPC-3 tumor line has been maintained for more than four years in our laboratory and represents a valuable model for primary human pancreatic cancer.

Six-year follow-up of the clinical significance of karyotype in acute lymphoblastic leukemia

To evaluate the importance of pretreatment karyotype in predicting long-term outcome in acute lymphoblastic leukemia (ALL), we performed a follow-up study of the 329 patients from the Third International Workshop on Chromosomes in Leukemia. Living patients have now been followed a minimum of 6 years. Patients were divided into ten groups according to pretreatment karyotype: no abnormalities, one of the following structural abnormalities [the Philadelphia chromosome, rearrangements involving 8q24, t(4;11), 14q+, 6q-] or, in the remaining cases, modal number (less than 46, 46, 47-50, greater than 50). As previously reported for achievement and duration of complete remission, and overall survival, disease-free survival differed significantly (p less than 0.001) among chromosome groups for both adults and children. Among children, karyotype was an independent prognostic factor for predicting disease-free survival. Because of the long follow-up, we now have been able to utilize statistical models to estimate the percentage of patients cured, according to karyotype alone and combined with other risk factors. Adults with the highest likelihood of cure (21-33%) were those patients with FAB-L1, a leukocyte count of 50,000/microliters or less, and one of the following chromosome groups: greater than 50, 47-50, 6q-, or normal. In children these same characteristics were associated with the highest percentage of cure (58-71% cured). In addition, we identified several groups of children with less than 15% chance of cure who clearly need to be treated as high-risk patients at diagnosis. Future studies of patients who have received risk-adapted therapy based on these chromosome data are needed to determine if more intensive treatment will improve the outlook of patients with cytogenetically unfavorable types of ALL.