A 68-year-old man with acute myelogenous leukemia (M2) was induced to complete remission by chemotherapy consisting of BH-AC and ACM-A on the 180th hospital day. Prior to therapy, chromosome analysis revealed 46, XY, del(5)(q22q33). No additional chromosome abnormalities were noted. Though 5q- was first associated with a preleukemic state, it is now known to be found in several different hematological disease. It has been suggested that patients with only a 5q- abnormality might have a better prognosis than those with a 5q- plus additional chromosome abnormalities. 5q- usually results from an interstitial deletion with break and fusion points at 5q11 or 12, 5q14 or 15, 5q22 and 5q33 or 35. The c-fms oncogene is located in the vicinity of band 5q34, so that a chromosome break at 5q33 or 34 may play an important role in the hematological disorders with 5q- chromosome abnormality.

Methotrexate (MTX) is extensively used, both as single agent and in combination regimens, for the treatment of human choriocarcinoma. However, development of resistance to MTX occurs frequently following continued administration, resulting in the failure of chemotherapy. Thus, the present study was undertaken to explore the mechanisms acquiring MTX resistance in choriocarcinoma cells. Seven MTX-resistant sublines were selected stepwise from two human choriocarcinoma cell lines (HCCM and CCl). The development of resistance to MTX was associated with an impaired transport of MTX into the cell and a ten-fold increase of dihydrofolate reductase (DHFR) activity. The former mechanism was responsible for cells resistant to the low MTX concentration. An increase in DHFR activity has been observed in cells resistant to 10(-6) M MTX concentration. Southern blot analysis of DNA from parent and resistant lines demonstrated the 8.7-fold amplification of the DHFR gene in the line resistant to 10(-7) M MTX concentration. Thus, the gene amplification preceded an increase of DHFR activity. Those results suggested that amplification of DHFR gene led the increase of DHFR m-RNA and of DHFR protein, providing the MTX resistance of human choriocarcinoma cells. The incidence of double-minute chromosomes (DMS) in metaphasic cells paralleled with the resistant MTX concentrations. Since DMS were also present in cells not showing DHFR gene amplification, however, mechanisms other than DHFR gene amplification was responsible for the de novo synthesis of DMS.

By means of a 5-bromodeoxyuridine incorporation and acridine orange fluorescence staining method together with 3H-thymidine autoradiography, I studied the chronology of X chromosome replication in newly formed cell hybrids between the hypoxanthine phosphoribosyl transferase-deficient OTF9-63 murine embryonal carcinoma cell and the female rat thymocyte. Most near-tetraploid hybrid cells retained all chromosomes from both parents including one mouse X and two rat X chromosomes throughout the period of this study. Data showing changes in the chronology of X chromosome replication obtained here were indicative of reactivation of the inactive X chromosome from the rat thymocyte, and de novo X-inactivation of one or two X chromosomes. The extinction of lymphocyte phenotypes from the hybrids and their subsequent differentiation to the cell type resembling endoderm found in the peri-implantation mouse embryo were apparently in parallel with the above changes. These data thus demonstrated that there is a close causal correlation between the X-inactivation process and the cell differentiation.

HLA was studied in 35 patients with gliomas (20 anaplastic gliomas, 11 astrocytomas, 2 ependymomas, 2 oligodendrogliomas) and 38 volunteers who served as controls, by using the microdroplet lymphocyte cytotoxicity test. Phenotype frequency (PF), gene frequency (GF) and relative risk (RR) of each HLA antigen were studied statistically with the chi 2-test, where corrected P (CP) less than 0.05 was considered significant. Concerning HLA-B antigens, either Bw 61 or Bw 62 was found in 45.7% of the patients and the both in 14.3%. HLA-Bw 61 had a tendency to increase in the patients (PF = 0.46, GF = 0.27, RR = 7.16, chi 2 = 9.64, P less than 0.002, CP less than 0.064). Contrary to HLA-B antigens, HLA-DRw 6 was absent in the patient (chi 2 = 8.3379, P less than 0.004, CP less than 0.04). No relation between HLA and histological types was found. HLA has its genetic locus on the short brachium of the 6th chromosome and complement C2, C4, properdin, etc are considered to link HLA. Immunoregulatory genes (Ir genes), immunosuppressive genes (Is genes), disease susceptibility genes and disease resistant genes are also considered to link HLA, especially HLA-B, D loci. Although diseases are multifactorial, according to our report, the incidence of HLA-Bw 61 is higher, while that of HLA-DRw 6 is lower in patients with glioma. These phenomena seem very interesting considering the previous evidence that HLA has a close relation between disease susceptibility and immunological competence.(ABSTRACT TRUNCATED AT 250 WORDS)

The ability of macrophages to induce drug-resistant mutants was studied in an in vitro, macrophage-tumor cell coculture system utilizing the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus as measured by resistance to 6-thioguanine. Tumor cells of the metastatic mouse mammary tumor line 66 were sensitive to macrophage induction of thioguanine resistance as shown by an increase in the frequency of thioguanine resistant variants which arose following macrophage coculture to levels at least 5 to 10 fold above the spontaneous frequency. This increased frequency was not seen in a series of related, generally nonmetastatic lines. Detection of increased numbers of variants depended upon the macrophage to tumor cell ratio, with 50:1 or greater being necessary. The activity of the macrophages was dependent upon their activation stage. The induction of drug-resistant variants could be inhibited by oxygen radical scavengers. The basis for the emergence of thioguanine resistant cells appeared to be induction of new variants rather than selection of pre-existing resistant cells from the parental population since thioguanine sensitive and resistant cells were equally sensitive to macrophage mediated toxicity. In 6 of the 6 macrophage-induced variants tested, resistance was associated with loss of HGPRT activity. The reverse mutation frequency rate at the HGPRT locus in 5 macrophage-induced variants was low and similar to that of a stable, ethyl methanesulfonate-induced thioguanine resistant line, suggesting that macrophage induction of thioguanine resistance was the result of a true mutation, rather than an epigenetic event. Macrophages isolated directly from growing mammary tumors, as well as activated peritoneal macrophages, were capable of inducing thioguanine resistance in line 66 cells.

The limits of FCM detection of nuclear DNA aneuploidy were determined by simulation of the relationship between the coefficient of variation (CV) and DNA difference of two populations using a microcomputer. Under ideal conditions, the minimal DNA difference necessary for a bimodal peak is almost twice the CV. When the DNA difference is below the value, a single peak with a large CV and/or a shoulder is formed. Cases with a larger CV than expected in a single population should be practically treated as a population mixed with the near-diploid line.

A new human carcinoma cell line (HEC-1), which was derived from low differentiated adenocarcinoma of the endometrium, has been established. Cells from tumor tissues grown in athymic mice were cultured in minimal essential medium supplemented with 20% fetal calf serum. Contaminated mouse fibroblasts were removed from the culture by the absorption of anti-mouse serum. Continuous cell growth (doubling time: 51.6 hrs) could be observed during 64 passages. The cultured cells appeared monolayer and the cellular arrangement was a pavement-like pattern. The morphology of cells was analogous to the one of adenocarcinoma cells. The modal number of chromosomes of the original tumor cells were 46. The t. dic (1; 16)(p21; q24) marker which had been identified as the clonal abnormality in the original tumor cells, was also observed consistently in cultured cells, though the loss of chromosome 19 was disappeared during the passage. This suggested that the rearrangements of the long arm of chromosome 1 played an important role for the endometrial carcinogenesis.

Cytogenetic studies were performed on endometrial specimens of four patients with hyperplasia. Six with adenocarcinoma and one with mixed mesodermal tumor. All 65 cells obtained from hyperplasia specimens excluding one cell, had a normal female karyotype. However, cells from five adenocarcinoma specimens had chromosomal abnormalities, though a specimen of a well differentiated adenocarcinoma showed a normal karyotype. A few numerical abnormalities which were clonal in origin, were noted in one case each. Three kinds of structural abnormalities involving chromosomes 1 were identified as clonal in origin; del (1) (p21), t. dic(1; 16) (p21; q24), and i (lq). Since carcinoma cells had two chromosomes 1 of normal morphology, the presence of the marker chromosome led to the partial trisomy or tetrasomy of the long arm of a chromosome 1, being characteristic of cells from adenocarcinoma of the endometrium. A successively transplantable tumor has been produced from a poorly differentiated carcinoma cells with the t. dic (1; 16) (p21; q24) marker chromosome. Histological and chromosomal examinations were performed in cells from the passage 1, 4 and 5 tumors in order to explore the role of this marker played in the formation of the endometrial carcinoma. Though the degree of differentiation status of tumor cells had been changed during transplantations, the t. dic (1; 16) (p21; q24) marker were observed consistently among these cells. This suggested that the rearrangement of chromosome 1 was not produced as a result of genetic instability due to tumor progression, but rather specifically associated with the endometrial carcinogenesis. None of karyotypic changes excluding the marker and the tetraploid was responsible for these phenotypic changes.

A case of familial occurrence of intracerebral cavernous angioma is reported. The patients were a mother and her eldest son, a 48-year-old woman and a 28-year-old man, respectively. The mother, a hypovascular mass in the right frontal lobe was excised surgically, and in the son a well demarcated mass in the left temporal lobe was extirpated. Pathological examination in each case revealed cavernous angioma. Familial occurrence of intracerebral cavernous angioma is extremely rare. In the literature, 8 cases of familial occurrence have been reported, including our case, and in three out of the 8 cases the lesions were histologically confirmed. To our knowledge, this is the first case in Japan in which the diagnosis was established by surgical specimen. Of 17 cases in 8 family lines, multiple occurrence was observed in 7 cases. The clinical manifestations of the disease appear mostly in a form of adult epilepsy or intracerebral hematoma, and rarely sudden death associated with intracerebral hematoma. At present, CT scanning is widely used for diagnosis of the disease, and the lesions are surgically curable if they are located at the accessible sites. Although there has been no evidence of genetic basis, it is interesting that there is familial occurrence. From this point of view, we should carefully check the family tree of such patients.