Phase II study of flutamide in the treatment of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a male predominant disease and may be an androgen-dependent or androgen-responsive tumor. This Phase 11 study was designed to investigate the clinical activity and toxicity of flutamide in the treatment of patients with advanced HCC.

METHODS

Thirty-two patients with measurable advanced HCC were studied. Flutamide, 750 mg per day, was administered orally for 8 weeks. Ten patients died before repeat tumor measurements could be performed.

RESULTS

Twenty-two patients were evaluable for response and toxicities. There were no complete responses nor partial responses. Nine of 22 patients (41%) had stable disease and 13 patients (59%) had progressive disease. Serum alpha-fetoprotein was reduced in three patients. The median survival was 10 weeks (range, one to 35 weeks). Toxicities were minimal and tolerable.

CONCLUSIONS

Flutamide is not effective in the treatment of advanced HCC. Clinically, HCC may not be an androgen-responsive tumor. Other new methods of treatment of HCC warrants future clinical investigations.

Serum cytokine level fluctuations in chemotherapy-induced myelosuppression

We have reported that serum granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) levels rise in patients with chemotherapy-induced myelosuppression. The aim of the present study was to determine whether other cytokines that function at different hematopoietic stages also fluctuate during chemotherapy-induced myelosuppression and whether the extent of cytokine level fluctuations correlate with myelosuppression severity. Fifteen patients participated in the study. Serum levels of stem cell factor (SCF), interleukin (IL)-1 alpha, IL-6, IL-3, granulocyte-macrophage CSF (GM-CSF) and G-CSF were analyzed before chemotherapy and during the myelosuppressive stage and correlations between cytokine levels and myelosuppression severity were examined. The results showed that both serum G-CSF and IL-6 levels rose in patients with chemotherapy-induced myelosuppression. The prechemotherapy serum G-CSF and IL-6 levels correlated well with their respective elevated levels during the myelosuppressive stage. The myelosuppression severity also correlated well with the extent of serum G-CSF level elevation. The serum IL-6 and G-CSF levels during the myelosuppressive stage correlated significantly. Serum SCF levels did not fluctuate significantly during myelosuppression, and IL-1, IL-3 and GM-CSF were rarely detected in serum even after chemotherapy. In the present study, the roles of IL-1 alpha, SCF, IL-3 and GM-CSF chemotherapy-induced myelosuppression were not clear.

Elevation of serum IL-6 levels in patients with acute bacterial infection

BACKGROUND

Serum cytokine levels have been reported to elevate in acute bacterial infection, but the relationship of differential elevation in cytokine levels to patients' clinical parameters and prognosis remains controversial. The present study was designed to evaluate whether serum interleukin-1 alpha (IL-1 alpha) and IL-6 levels were raised in patient with acute bacterial infection, and were correlated with patients clinical parameters.

METHODS

Thirty patients, aged from 20 to 91 years, calling our emergency room with clinical evidence of acute bacterial infection and marked leukocytosis, were enrolled in this study. Sera were collected immediately and analyzed for IL-1 alpha and IL-6 levels with Enzyme-Linked Immunosorbent Assay (ELISA) method.

RESULTS

All patients with acute bacterial infection had measurable higher levels of serum IL-6 than normal volunteers. Patients with higher serum IL-6 level were more likely to have fever, though without statistical significance (p = 0.09). Serum IL-6 levels did not correlate significantly with positive blood culture result, septic shock, or fatal outcome. Serum IL-1 alpha levels were below minimal detectable concentrations in all patients checked.

CONCLUSIONS

Serum IL-6 levels were elevated in patients with acute bacterial infection, and were possibly associated with the occurrence of fever. IL-1 alpha played no obvious role as systemic effector molecule in acute bacterial infection in our study.

The prognostic value of serum cytokine levels in patients with acute infections

BACKGROUND

Elevation of serum cytokine level, especially tumor necrosis factor-alpha (TNF-alpha) and granulocyte-colony stimulating factor (G-CSF), has been reported in acute bacterial infection. Elevation of serum TNF-alpha level upon patients' admission has also been reported to correlate with the fatal outcome.

METHODS

The present study is to evaluate, in addition to TNF-alpha and G-CSF, whether serum stem cell factor (SCF), interleukin-3 (IL-3) and granulocyte-macrophage-CSF (GM-CSF) levels to see if they were also elevated in patients with acute bacterial infection. It also tries to evaluate whether different degree of elevation of cytokine levels had any relationship to patients' clinical parameter, including fatality. Correlation between different kinds of cytokines was also studied.

RESULTS

Patients with bacterial growth in blood culture had higher level of serum G-CSF. Higher level of serum TNF-alpha was significantly associated with the occurrence of septic shock, but not of fatal outcome. Low serum G-CSF and high serum SCF level were significantly associated with fatal outcome; however, all the patients still had serum SCF levels within normal range. GM-CSF and IL-3 play no obvious role as systemic effector molecule in acute bacterial infection.

CONCLUSIONS

Higher levels of serum TNF-alpha are associated with the occurrence of septic shock. Low serum G-CSF levels are significantly associated with fatal outcome. Routine monitoring of serum G-CSF level in patients with severe infection in order to supplement recombinant G-CSF can possibly help patients to overcome the disaster.

Leukemoid reaction resulting from multiple cytokine production in metastatic mucoepidermoid carcinoma with central necrosis

We report a male patient with metastatic high-grade mucoepidermoid carcinoma and associated leukemoid reaction. The patient was transferred to our hospital due to persistent spiking fever, marked granulocytosis, and suspected liver abscess. After thorough bacteriological studies, including cultures of blood and material aspirated from the "liver abscess", no evidence of infection was documented. The patient suffered from persistent spiking fever for more than 4 weeks in spite of empirical antibiotic treatment, and repeated aspiration of the presupposed liver abscess. He underwent exploratory laparotomy for intended surgical evacuation of the liver abscess and bacteriological diagnosis. The operative findings were compatible with metastatic carcinoma with multiple liver and retroperitoneal lymph node involvement and tumor necrosis. The pathology report indicated high-grade mucoepidermoid carcinoma. Immunohistochemistry showed positive staining for interleukin-1 alpha (IL-1 alpha) and IL-6. Elevation of cytokine levels in the necrotic tumor fluid, including IL-1 alpha, IL-6, granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor was confirmed by ELISA test. This case shows that multiple cytokine production from a metastatic tumor and its central necrotic area in the liver can produce a febrile leukemoid reaction mimicking a pyogenic liver abscess.

Renal cell carcinoma. Cytogenetic analysis of tumors and cell lines

Successful cytogenetic analysis was performed on 27 samples from 25 patients with RCC, including 7 of 11 tumors studied and 20 cell lines. Clonal chromosomal abnormalities were detected in all 27 samples. The most frequently involved chromosomes were 7, 1, 3, 9, and the Y (20, 17, 17, 14, and 10 cases, respectively). Polysomy 7 or rearrangement of 7q was seen in 80% (20/25) of the patients, and loss or rearrangement of 3p was seen in 48% (12/25); of the latter, four patients had loss of the whole chromosome and 10 patients had deletions or translocations involving 3p, with breakpoints at either 3p11-14 or 3p21-23 (5/7 translocation breakpoints were at 3p21-23). Loss of the sex chromosomes was seen in 15 patients, including -Y in 10/22 males. Other clonal changes included structural abnormalities of chromosome 1 centromere and the long arm, breakpoints at or near the centromere of chromosome 9 (10 patients), polysomy 16, monosomy 17, polysomy 20, and monosomy 22. With the exception of chromosome 3p loss, which was primarily confined to the nonpapillary cases, no specific clonal abnormality was noted for any particular subtype of RCC. Trisomy or tetrasomy 7 and -Y were seen in all subtypes of renal cell carcinoma.

Elevation of serum interleukin-6 levels before peak of serum granulocyte colony-stimulating factor level in chemotherapy-induced myelosuppressive patients

The aim of this study was to ascertain whether any cytokines that function in earlier stages of hematopoiesis also fluctuate in conjunction with granulocyte colony-stimulating factor (G-CSF) in chemotherapy-induced myelosuppression. A total of seven patients were studied. All patients received 3 days of intravenous injection of combination chemotherapy. Patients' absolute neutrophil count (ANC), platelet count, serum G-CSF, interleukin-6 (IL-6), IL-3, and IL-1 alpha were monitored before chemotherapy, and then daily or every other day thereafter during the entire treatment course until the ANC returned to normal. The results showed very obvious elevation of serum IL-6 level before or concurrent with the elevation of serum G-CSF levels at the neutrophil nadir in all seven patients. The rise of IL-6 also correlated with nadir platelet levels in six of seven patients. The finding of serum IL-6 elevation was statistically significant both in neutropenic and thrombocytopenic stages. Serum IL-3 level was below minimum detectable concentrations in all seven patients. Serum IL-1 alpha was below minimum detectable concentration in six patients and demonstrated no obvious fluctuation in the remaining patient. Therefore, the present study demonstrated the chronological time sequence of cytokine fluctuation, IL-6 peak before G-CSF, in chemotherapy-induced myelosuppression. According to this finding, when cytokines are used for prevention of myelosuppression or for acceleration of its recovery, it may be logical to use a combination of cytokines in sequence, such as IL-6 initially followed by G-CSF.

Molecular genetic characterization of neuroendocrine lung cancer cell lines

Small cell lung cancers express neuroendocrine (NE) cell features, while most non-SCLC tumors lack these features. We studied the cytogenetic and genetic alterations in cell lines derived from three unusual subtypes of lung cancer: including carcinoids, non-small cell lung cancers expressing NE properties (NSCLC-NE) and extrapulmonary small cell cancers (ExPuSC) and compared them with those of SCLC and NSCLC lines. Our studies included: cytogenetic studies, restriction fragment length polymorphism (RFLP) analyses with 8 probes spanning commonly deleted loci on chromosomes 3p, 13q and 17p, retinoblastoma gene product (RB) expression, and mutations in the ras and p53 genes. We also summarize previously published data on in vitro chemosensitivity patterns and MDRl gene expression. Our studies demonstrate that all three of the NE cell subtypes have their own distinctive genotypes and phenotypes, each having some similarities and dissimilarities with SCLC and NSCLC.

Metastatic nasopharyngeal carcinoma with epidural spinal cord compression: report of an unusual and catastrophic event

Nasopharyngeal carcinoma (NPC) with epidural metastasis of spinal cord has rarely been reported. We present an NPC patient with epidural spinal cord compression due to metastasis. In spite of emergent radiotherapy and large dose decadron treatment, this patient still had severe sequela of paraplegia and incontinence. The epidemiology, clinical findings, diagnosis, treatment and outcome of this metastatic epidural tumor compression were discussed.

Sequential analysis of 43 patients with non-Hodgkin's lymphoma: clinical correlations with cytogenetic, histologic, immunophenotyping, and molecular studies

Few reports correlating specific cytogenetic abnormalities with distinct subtypes of lymphoma have performed serial studies at diagnosis and at tumor recurrence or progression. In our file of 325 cytogenetically analyzed non-Hodgkin's lymphoma (NHL) patients studied over the past decade, 43 had serial biopsies, 39 of whom had at least two successful preparations; of the 43, nine had one and 32 had two or more cytogenetically abnormal specimens. In this study, we correlated cytogenetic, histopathologic, molecular, and clinical parameters. Patients with low-grade lymphomas were as likely as patients with intermediate- or high-grade lymphomas to acquire new chromosomal abnormalities with time (16 of 23 patients as compared with 7 of 16; P2 = .11, chi 2 test). In four patients, originally diagnosed indolent disease progressed to aggressive disease; all had t(14;18), all gained additional chromosomal abnormalities with disease progression, and three of the four expressed abnormalities associated with disease progression and/or short survival: der(18), +7, and/or +12. Cytogenetic results from early disease were compared with those obtained later in disease: in the t(14;18) group, the most common abnormalities were +7 (eight patients) and der(18) (five patients), both seen later in disease. The most common abnormalities in patients without t(14;18) were 6q deletions; they were seen in both early and late disease and were associated with significantly shorter survivals (P2 = .0014) compared with all patients without 6q deletions. Secondary chromosomal abnormalities, observed after at least one previous abnormal study, were seen in 19 of 22 t(14;18) patients and in 11 of 21 patients without t(14;18) and were associated with a poor survival (P2 = .13) compared with patients without any secondary chromosomal abnormalities. Chromosome 1 abnormalities were seen in almost half of the patients and were observed in initial specimens and early in disease as well as late in disease and as secondary abnormalities; 1q involvement was more frequent than 1p (15 versus eight patients) and was significantly associated with poor survival only in patients with intermediate-/high-grade disease; the most common breakpoints were 1q21-q22 (nine patients) and 1p36 (six patients). Breakpoints at 2q21 and 3q27-q29 were limited to patients with t(14;18) and were almost exclusively secondary in nature. Molecular studies in 24 of our patients showed discrepancies with the cytogenetic results in only three patients: two had t(14;18) but no molecular rearrangements while two patients had no visible t(14;18) but were positive for major breakpoint region (MBR) rearrangement. The presence of MBR or minor breakpoint cluster (MCR) rearrangement had no apparent effect on survival.(ABSTRACT TRUNCATED AT 400 WORDS)

Cytogenetic study of two cases with lymphoma of mucosa-associated lymphoid tissue

Cytogenetic studies have been reported in fewer than 20 patients with lymphoma of mucosa associated lymphoid tissue (MALT). Two patients with this disease at the Clinical Center, National Institutes of health had numerical and structural chromosome abnormalities, including +12 in both cases. The clonal karyotypes observed were 48-49,XX,t(2;8)(q33;p23), +3, -10,del(10)(q23), +12, +18 [cp] and 47,X,-X,i(6p), +7, +inv(12)(p13q13). Review of cytogenetic studies from published data showed that all cases of MALT lymphoma reported to date also have both numerical and structural chromosome abnormalities, the most frequent being numerical involvement of chromosomes 3, 7, and 12. Identification of a clonal abnormality can help establish the diagnosis when differential diagnosis includes atypical hyperplasia. Although trisomy 12 has been associated with a poor prognosis in B-cell chronic lymphocytic lymphoma (B-CLL), both these patients with MALT lymphoma have had long survival: 8 and 11 years, respectively.

Examination of human tumors for rhoA mutations

rhoA encodes a ras-related GTP-binding protein that is thought to play a role in cytoskeletal organization. Recent evidence has suggested both that rhoA could act either as a dominant oncogene, since transfection of both normal and activated rho genes confer a transformed phenotype on fibroblast cells in culture, or as a recessive tumor suppressor gene, by virtue, in part, of its chromosomal location at 3p21, a site deleted in many human malignancies. In either case, a role for rhoA in the oncogenesis of human tumors would be supported by the finding of rhoA mutations in tumors. We therefore examined human tumors and cell lines for mutations in the protein coding regions of rhoA by RNAase protection analysis. We first examined the expression of rhoA in renal cell carcinoma cell lines in which 3p21 was heterozygously deleted or retained. We found no evidence for rhoA mutations in these specimens. We also examined RNA from lung, breast, colon or ovarian tumors and also found no evidence of activating rhoA mutations. Furthermore, there was no relation between the level of rhoA mRNA expression and the presence or absence of 3p21 deletions in the renal cell carcinoma specimens. Thus, although rhoA has transforming potential in vitro, there is no evidence that it is activated by mutation in human malignancies, or that it could act as a tumor suppressor gene in tumors in which 3p21 is deleted.

Chromosome studies in HTLV-I, -II, and HIV-1, -2 cell lines infected in vivo and in vitro

HTLV-I, II and HIV-1, 2 are T-cell tropic viruses, all belonging to the retrovirus family. These viruses are transmitted horizontally by intimate contact or through blood products. The study of chromosomal changes in these T cells may enhance our understanding of the nature and mechanism of these viral infections. However, because of the cytopathic effect of these viruses on T cells, the direct observation of abnormalities in these cells is sometimes difficult. We performed chromosomal analysis on six HTLV-I cell lines from patients with HTLV-I-positive leukemia/lymphoma, one HTLV-I variant cell line, and two HTLV-II-positive cell lines. The results of these studies were compared with the findings in an earlier (published) study of direct preparations and short-term cultures of cells from 11 HTLV-I-positive NIH patients. Our study also included cytogenetic analysis of seven established cell lines and six normal peripheral bloods infected in vitro with the HTLV-IIIB strain of HIV-1 (five cell lines and six bloods) or HIV-2 (two lines); all were studied both before and after viral infection. The results showed that all six HTLV-I cell lines and the variant cell line had multiple chromosomal changes: three lines had deletions of chromosome 6, with breakpoints between q21 and q25. Nine of the 11 NIH patients with HTLV-I had clonal abnormalities, and six of these nine had chromosome 6 deletions with breakpoints ranging from band q11 to band q23. The high incidence of 6q involvement may be of considerable significance in this clinical subgroup of HTLV-I patients. The two HTLV-II cell lines were established from patients suffering from HTLV-II infection. Both of these cell lines had translocations of chromosome 21 at p11, and both had extra copies of chromosome 20; no known oncogenes or receptors are located on these two chromosomes. Chromosome 17 was the chromosome most frequently involved (three lines) in the five HIV-1-infected cell lines, followed by chromosomes 3 and 21; it is of interest that NGL (also known as C-ERBB2 or NEU oncogene), CD7 (a lymphocyte antigen), HTLV-1 receptor, NGFR (nerve growth factor receptor), and MIC6 are all cell surface antigens coded by genes on chromosome 17q. No specific chromosome abnormalities were found in the normal blood samples infected with HIV-1, and no unique chromosome changes were noted in the two cell lines infected with HIV-2; however, the infected H9 line had a chromosome 17 abnormality, a translocation involving band 17p11.

Significance of chromosomal changes in patients of different age groups with acute leukemia

Chromosome abnormalities have been observed in about 50% of patients with acute leukemia. There have been several published reports which emphasized the chromosomal changes in relation to the age of the patient and the morphologic type of acute leukemia. All observations suggest that there are both age related similarities and differences. The karyotype is an important independent prognostic factor in acute leukemia; however, age alone (especially above age 70) is the single most important factor for a poor prognosis.

Cytogenetic studies in subgroups of rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood and accounts for 10% of all solid tumors in children. There are three different histologic forms of this tumor: embryonal (RMS-E), alveolar (RMS-A), and primitive (RMS-P). Among these, the embryonal form has responded well to chemotherapy. Identification of the correct subtype is important for both the management and treatment of this malignancy. However, the histopathologic classification of RMS is sometimes difficult and distinguishing between the embryonic and primitive forms can present a diagnostic dilemma. Chromosomal abnormalities have been observed in all subtypes. We present the cytogenetic findings in six cases of RMS or related sarcoma. All four cases with RMS-A had both numerical and structural abnormalities in the tumor and involved bone marrow specimens. Three patients had a common marker, t(2;13)(q37;q14), and one patient had a variant marker involving 13q14, t(1;13) (p36;q14), and double minutes (dmin). The single embryonal RMS patient had modal chromosome numbers in the hypertriploid range and extensive structural abnormalities; the t(2;13) was not present, but translocation of 13q to both 1q and 2p was observed, der(1)t(1;13)(q21;q14) and der(2)t(2;13)(p25;q14). The patient with primitive type RMS had a hypodiploid line with several markers, including a complex translocation involving chromosomes 5 and 13 with a breakpoint at 13q14, and t(11;12)(q24;q12), a chromosome marker heretofore found only in Ewing's sarcoma and related tumors. This patient had atypical RMS with mixed neural and myogenic elements. The significance of these chromosomal markers and their importance in the characterization of childhood tumors are discussed, along with a review of the literature.

Absence of hereditary p53 mutations in 10 familial leukemia pedigrees

Germline p53 mutations have been identified in the Li-Fraumeni syndrome but the role of such mutations in familial leukemia is not established. The p53 gene was examined by single-strand conformation polymorphism analysis of exons 4-8 in 10 families with multiple members affected with leukemia. The diagnoses included acute and chronic leukemias and Hodgkin's disease. Identified in two families were p53 mutations that were nonhereditary. These included a 2-bp deletion in exon 6 found in the lymphoblast DNA of one child whose sibling, cousin, and several adult relatives had acute leukemia. The other nonhereditary p53 mutation was a transition at codon 248 (CGG to CAG, arginine to glutamine) found in the lymphoblasts of a patient with a preleukemic syndrome and acute lymphoblastic leukemia (ALL) whose brother is a long-term survivor of ALL. Thus, p53 mutations were found to occur in two families but both were nonhereditary. Moreover, in the remaining eight families no p53 mutation was identified in the regions of p53 where most mutations have been found in other cancers. Although p53 mutations sometimes may be present, they do not appear to be a primary event responsible for hereditary susceptibility to familial leukemia. This study suggests involvement of other genes or mechanisms.

T-cell lymphoblastic lymphoma with eosinophilia associated with subsequent myeloid malignancy

Three patients with T-cell lymphoblastic lymphoma and peripheral blood eosinophilia are reported. At the time of diagnosis, all patients had lymphadenopathy, and one had a mediastinal mass. Lymph node biopsies revealed lymphoblastic lymphoma admixed with a variable number of mature eosinophils. Immunophenotypic studies demonstrated that each lymphoma had an immature T-cell immunophenotype. Bone marrow biopsies were hypercellular with myeloid hyperplasia and eosinophilia but were negative for lymphoma. All patients received multiagent chemotherapy; one patient achieved a complete remission, and two patients had partial remissions. All patients subsequently developed a myeloid malignancy. Two died of acute myeloid leukemia within 18 months of the diagnosis of lymphoblastic lymphoma. The third patient relapsed with a lymphoma that had histologic and immunophenotypic features of both T-cell lymphoblastic lymphoma and granulocytic sarcoma and also developed a poorly defined myeloproliferative disorder. These findings suggest that T-cell lymphoblastic lymphoma associated with eosinophilia may represent a distinct clinico-pathologic entity with a high risk of subsequent myeloid neoplasia.

Hereditary and acquired p53 gene mutations in childhood acute lymphoblastic leukemia

The p53 gene was examined in primary lymphoblasts of 25 pediatric patients with acute lymphoblastic leukemia by the RNase protection assay and by single strand conformation polymorphism analysis in 23 of 25 cases. p53 mutations were found to occur, but at a low frequency (4 of 25). While all four mutations were identified by single strand conformation polymorphism, the comparative sensitivity of RNase protection was 50% (2 of 4). Heterozygosity was retained at mutated codons in 3 of 4 cases. One pedigree was consistent with the Li-Fraumeni syndrome, and bone marrow from both diagnosis and remission indicated a germline G to T transversion at codon 272 (valine to leucine). Although members of another family were affected with leukemia, a 2-bp deletion in exon 6 was nonhereditary. The other two nonhereditary p53 mutations included a T to G transversion at codon 270 (phenylalanine to cysteine) and a G to C transversion at codon 248 (arginine to proline). These data support the role of both hereditary and acquired p53 mutations in the pathogenesis and/or progression of some cases of childhood acute lymphoblastic leukemia.

Nonrandom structural and numerical chromosome changes in non-small-cell lung cancer

Cytogenetic studies were performed on 27 tumor cell lines (most of which were derived from metastatic lesions) and four fresh malignant pleural and pericardial effusions from 30 patients with non-small-cell lung cancer (non-SCLC). Many clonal structural (deletions and nonreciprocal translocations) and numerical abnormalities were found in each specimen. Statistical analysis revealed these changes were nonrandomly distributed among the chromosomes. A statistically significant number of chromosomal breakpoints were seen in regions 1q1, 1q3, 3p1, 3p2, 3q1, 3q2, 7q1, 13p1, 14p1, 15p1, and 17q1 when the regions were compared to the total haploid complement. In addition, when a given region was compared to other regions within the same chromosome, statistically significant numbers of breakpoints were noted for regions 1q3, 5q1, 7q1, 13p1, 14p1, 15p1, 16q2, 17q1, and 21p1. Specific chromosome bands showing the most frequent involvement in structural abnormalities were (in descending order) 3p14.2, 3q21, 19q13, 11p15, 1q11, 7q11, 1q21, 3p23, and 3p21. The breakpoints indicate areas to look for new dominant oncogenes activated by translocations, while the areas of deletions and loss of material by nonreciprocal translocations highlight areas to search for recessive oncogenes. These cytogenetic studies represent strong evidence that multiple genetic lesions are associated with the development of metastatic lung cancer, and provide a roadmap to search for new genes involved in the pathogenesis of lung cancer.

Induction of topoisomerase II gene expression in human lymphocytes upon phytohemagglutinin stimulation

The carboxyl-terminal one-third of human topoisomerase II polypeptide expressed in Escherichia coli was used as antigen to generate polyclonal antibodies in rabbits. With the use of antiserum, DNA topoisomerase II levels of phytohemagglutinin-stimulated human lymphocytes were measured by immunoblotting. Our results showed that the increase in intracellular topoisomerase II level paralleled the entry of cells into proliferation. We also found that the increase in the topoisomerase II level resulted from an increase in the amount of topoisomerase II mRNA. The time course study indicated that the appearance of topoisomerase II mRNA was first observed at 36 h after phytohemagglutinin stimulation. The maximal level of topoisomerase II mRNA was seen at 45 h after stimulation. The same RNA blot was rehybridized with a thymidine kinase probe. The maximal level of thymidine kinase mRNA was observed at 39 h after phytohemagglutinin stimulation. In a comparison of the time course of topoisomerase II gene expression with that of [3H]thymidine incorporation and thymidine kinase gene expression, it was found that the expression of the topoisomerase II gene was later than the onset of DNA replication. Thus, this study suggests that topoisomerase I, which is constantly expressed throughout the cell cycle, might participate in the initiation of DNA replication, while topoisomerase II is involved in solving the DNA topological problems accompanying DNA strand separation during DNA replication.

Cytogenetic studies of esophageal carcinoma cell lines

Although the incidence of cancer of the esophagus is low in the United States, the prognosis of patients with this malignancy is poor, especially when metastases exist. More research concerning the biological characteristics of this tumor is necessary to permit more effective treatment and to determine the etiology. We successfully studied cytogenetically 14 short- and long-term cell lines derived from esophageal carcinoma to determine whether these tumors have nonrandom, unique chromosomal abnormalities. Our results showed that the tumor cells had chromosome numbers clustering around a modal number that varied according to the cell line. The presence in the primary explant of extensive numerical and structural abnormalities involving every chromosome including the sex chromosomes indicate that these abnormalities occur early in the malignant cells. The chromosomes most frequently involved in the structural abnormalities were 1, 9, and 11, each occurring in 13 of the 14 lines, and of three found in 12 of the 14 lines. The major aberrations resulted in deletions of portions of these chromosomes. The most frequent breakpoints for these abnormalities occurred at 3p14, 11q11q12; and 9q11q12 as well as in the centromeric regions of all the acrocentric chromosomes. Another unusual chromosomal marker found in three lines (HCE-1, HCE-3, and HCE-5) was a homogeneously staining region (HSR) that occurred as an extension on 11q12.

Retention of chromosome 3 in extrapulmonary small cell cancer shown by molecular and cytogenetic studies

In small cell lung carcinoma, one of the short arms of chromosome 3 is typically lost. To investigate chromosome 3 in extrapulmonary small cell carcinoma, we used DNA probes that detect restriction-fragment-length polymorphisms at loci on 3p. These probes were used to study DNA extracted from tumors and normal tissues and/or tumor cell lines from five patients with extrapulmonary small cell cancer. Tumor DNA from four of the five patients with extrapulmonary small cell cancer retained heterozygosity at loci on 3p. Cytogenetic studies of the tumor cell lines established from these four patients showed retention of both short arms of chromosome 3. We conclude that the loss of genetic material from 3p observed in small cell lung cancer is not typical in extrapulmonary small cell cancer.