Adult T-cell leukemia: structures and expression of the p53 gene

Experiments were undertaken to investigate a genetic event involved in leukemogenesis in adult T-cell leukemia (ATL). For this purpose, the p53 gene was chosen for study, since alteration of the gene has been found in a wide variety of human cancers. Structures and expression of the p53 gene in ATL cells were investigated by Southern and Northern blot analyses and a polymerase-chain-reaction single-strand conformation-polymorphism (PCR-SSCP) analysis. Either subtle alterations of the p53 gene or the absence of detectable level of p53 mRNA were found in 2 of 3 acute ATL cell lines and 2 of 12 acute ATL fresh samples. In contrast, no mutation was detected in 4 cases with less aggressive types of ATL (3 chronic and 1 smoldering ATL cases). Mutations found in acute ATL cells occurred in regions highly conserved in evolution and all the cells carrying p53 mutation showed loss of the other p53 allele. These results suggests that alteration of the p53 gene may contribute to progression of the disease in some cases of ATL.

p53 gene mutations in gastric cancer metastases and in gastric cancer cell lines derived from metastases

Structural alterations of the p53 gene were investigated in tissue specimens of gastric and cervical cancers and in cell lines of gastric, esophageal, and cervical cancers, by polymerase chain reaction-single-strand conformation polymorphism analysis. Two of the four gastric cancer metastases and four of the eight cell lines originally established from gastric cancer metastases were found to have p53 gene alterations in the exon 5 to 11 region; point mutations and amino acid replacements were detected in a liver and an ovary metastasis at exon 7, in the TMK1 and MKN1 cell lines at exon 5, and in the OKAJIMA cell line at exon 10. The normal allele was not found in these cell lines. In the KATO-III cell line, gross deletion and rearrangement of the p53 gene were noted. However, no p53 mutations were identified in 19 primary lesions of gastric cancer, suggesting that the p53 gene abnormality preferentially occurs in the advanced stages of gastric cancer. In contrast to the gastric cancer, none of the 13 esophageal cancer cell lines, including two cell lines established from metastases, and none of the four cervical cancer cell lines showed any aberration in exons 5 to 11 of the p53 gene. During the course of the study, a novel polymorphism in intron 7 of the p53 gene was found, which can be recognized by restriction enzyme digestions of the polymerase chain reaction product.

Newly established uterine cervical carcinoma cell line with co-amplification of human papillomavirus DNA and c-myc gene

A new human tumor cell line, NCC-c-CX-1 (CX-1), was established from a uterine cervical cancer xenografted in nude mice. This cell line harbored approximately 50 to 100 copies of human papillomavirus (HPV) type 18 DNA per haploid genome, and contained about 16-fold-amplified c-myc gene with rearrangement. These genomic alterations found in CX-1 cells were also present in both primary tumor and xenografted tumor. Histopathologically, original and xenografted tumors were poorly differentiated cancer and were characterized by neuroendocrine features such as positive neuron-specific enolase and chromogranin A by immunohistochemistry and abundant neurosecretory-type granules in the cytoplasm by electron microscopy. However, the established cell line had lost the neuroendocrine features. This cervical cancer cell line may be a useful model for studying cervical carcinogenesis, especially the interaction between HPV and c-myc oncogene.

Allelic loss on chromosome 17p and p53 mutations in human endometrial carcinoma of the uterus

To understand the involvement of allelic losses and inactivation of tumor suppressor genes for the development of endometrial carcinoma of the uterus (EC), 24 cases of EC were examined for loss of heterozygosity (LOH) using a total of 57 polymorphic DNA markers covering all 23 pairs of chromosomes. LOH was observed at 27 loci on 10 different chromosomes, i.e., chromosomes 1, 3, 6, 11, 13, 15, 17, 18, 20, and 21, but was not detected at loci on chromosomes 4, 5, 7, 9, 10, 12, 14, 16, and X. It was observed only in seven of 24 cases, and the other 19 cases did not show LOH at any loci examined, including five cases of tumors with a high proportion of adenomatous hyperplasia. Among seven tumors with LOH at one or more loci, five tumors showed LOH at loci on the short arm of chromosome 17. Furthermore, mutations of the p53 gene, which is located on the short arm of chromosome 17, were detected in three of these 24 tumors by a polymerase chain reaction-single strand conformation polymorphism analysis and subsequent DNA sequencing. In two of these three tumors, p53 mutations were accompanied by the loss of wild-type p53 alleles. These results suggest that inactivation of the p53 gene is involved in the development of EC as in the case of several other types of human cancers.

Frequent allelic losses and mutations of the p53 gene in human ovarian cancer

The p53 gene on chromosome 17p is considered to be a tumor suppressor gene, and frequent mutations of the p53 gene have been found in a wide variety of human cancers. We examined 31 ovarian cancers for allelic losses and mutations of the p53 gene by polymerase chain reaction-single strand conformation polymorphism analysis as well as restriction fragment length polymorphism analysis. Allelic loss of the p53 gene was detected in 16 of 20 cases (80%). Mutations were detected in 9 of 31 cases (29%): 2 cases in exon 4; 5 cases in exons 5-6; and 2 cases in exons 7-8. In 8 of 9 cases, p53 mutations were accompanied by losses of the normal allele. These alterations of the p53 gene were commonly detected from stage I to stage IV. These results suggest that alterations of the p53 gene play an important role in the development of human ovarian cancers.

Acceleration of superoxide production from leukocytes in trauma patients

Superoxide (O2-) and granulocyte elastase (GE) from neutrophils mediate host defense and tissue injury in inflammation. To determine alterations in leukocyte function after trauma, O2- production and GE secretion from neutrophils were studied in trauma patients (n = 20) and healthy controls (n = 15). The priming effect of tumor necrosis factor (TNF), interleukin-1 alpha (IL-1 alpha), and lipopolysaccharide (LPS) on O2- or GE release also was evaluated. Superoxide production (nmole/10 minutes) was elevated significantly in trauma patients at days 0 (9.5 +/- 4.8), 1 (14.2 +/- 7.3), and 3 (12.2 +/- 5.9) and returned to control levels (4.2 +/- 1.6) by day 7. There was no difference in GE secretion between trauma patients and healthy controls. Incubation of neutrophils with TNF induced release of both O2- and GE. Superoxide production was induced by TNF at concentrations at or greater than 10(-11) mol/L. Granulocyte elastase secretion was induced in a time- and dose-dependent manner by TNF at concentrations between 10(-10) and 10(-7) mol/L. In contrast IL-1 alpha and LPS did not potentiate O2- or GE release. These results suggest that neutrophil O2- production increases acutely in trauma. Tumor necrosis factor may mediate this O2- and GE production by neutrophils involved in the inflammatory response.

Relation between nucleolar size and growth characteristics in small cell lung cancer cell lines

Relationships among cytological features, doubling time, S-phase percentage, expression of myc-family oncogenes, DNA ploidy and biochemical properties were studied in thirteen small cell lung cancer cell lines. Six cell lines that grew slowly (average doubling time 99 h) and had lower S-phase percentages (average 32%) showed inconspicuous nucleoli (average area of 1.5 microns 2), and the remaining seven cell lines that grew quickly (average doubling time 45 h) and had higher S-phase percentages (average 44%) showed large and prominent nucleoli (average area of 6.1 microns 2). DNA index value obtained from flow cytometric DNA histograms showed that all cell lines except for H-69 cell line displayed aneuploidy. Ribbon-like cell arrangements were observed in the 7 cell lines that grew quickly, and in 1 cell line that grew slowly. Biochemically, six slow-growing cell lines and four fast-growing cell lines showed high levels of aromatic L-amino acid decarboxylase activity, while in the remaining three fast-growing cell lines its level was low. A high level of c-myc or N-myc oncogene expression was observed in all 7 cell lines that grew quickly, but not in any of the 6 cell lines that grew slowly. It appears that small cell lung cancer cell lines that grow quickly can be expected to have large nucleoli and ribbon-like cell arrangements and to express high levels of myc-family oncogenes, and that nucleolar size is a good indicator for growth characteristics.

Chromosomal localization of putative tumor-suppressor genes in several human cancers

Restriction-fragment-length polymorphism analysis was performed on several different types of human cancers, including carcinoma of the uterine cervix, neuroblastoma, hepatocellular carcinoma, pheochromocytoma, stomach cancer, and small-cell lung carcinoma (SCLC), to determine the chromosomal loci of putative tumor-suppressor genes in each type of tumor because less of heterozygosity (LOH) is supposed to unmask the recessive mutation of tumor-suppressor gene in the remaining allele. Chromosomal loci showing frequent LOH differed among these tumors, suggesting that there are several tumor-suppressor genes in the human genome and that critical genes for the development of each type of tumor are different. In some cases LOH was observed in the early stage of tumor such as chromosome 3p loss in carcinoma of the uterine cervix, and in other cases it was observed only in the advanced stage of tumor such as chromosomes 4 and 16q loss in hepatocellular carcinoma. These results suggest that there are two different types of tumor-suppressor genes: one is the gene whose inactivation is responsible for malignant transformation of a normal cell and the other is the gene whose inactivation is responsible for the progression of a tumor cell. In SCLC, LOH at three different chromosomal loci, 3p, 13q, and 17p, was simultaneously observed in nearly 100% of tumors. It was observed even in stage I tumors and an untreated tumor, and it occurred prior to N-myc amplification. These results may imply that at least six genetic alterations are necessary to convert a normal cell into a fully malignant cancer cell in SCLC.

Resistance to anticancer drugs in NIH3T3 cells transfected with c-myc and/or c-H-ras genes

NIH3T3 cells transfected with c-H-ras and/or c-myc genes were examined for differences in drug sensitivity. The five transfectants used were N8, NIH3T3-nm-1, pT22-3-nm-2, pP1-4 and pT22-3. They were transfected with pKOneo alone, pKOneo and c-myc, pKOneo and c-myc plus activated c-H-ras, normal c-H-ras and activated c-H-ras genes, respectively. The IC50s of cisplatin, 4-hydroperoxycyclophosphamide, adriamycin, melphalan, and CPT-11 were significantly higher for NIH3T3-nm-1 abd pT22-3-nm-2 than for the parental NIH3T3 and N8 cells. Transfection with normal and activated C-H-ras oncogenes only led to increases in the IC50s of alkylating agents. There was no significant difference between the IC50s of N8 and those of NIH3T3 parental cells to any of these anticancer agents. These results strongly suggest that the expression of the c-myc gene plays a role in the acquisition of drug resistance. The c-myc gene may therefore provide us with an important clue in determining the mechanism of drug resistance.

Point mutation of the p53 gene resulting in splicing inhibition in small cell lung carcinoma

The p53 gene is functionally inactivated mostly by point mutations resulting in amino acid substitutions in a wide variety of human cancers. We found a novel mutation of the p53 gene in a small cell lung carcinoma cell line, Lu-143. One of the allelic p53 genes was lost accompanied by loss of heterozygosity for chromosome 17. In the remaining allelic p53 gene, there was a single-base substitution of G to T at position 1 within the splice donor site of intron 7, and the mutated intron was not spliced out during the mRNA maturation process. As a result of this mutation, larger sized p53 mRNA was expressed and no p53 specific protein was detected in this cell line. These results suggest that mutations causing splicing abnormalities are one of the molecular mechanisms for the p53 gene inactivation in human cancer.

Variable mutations of the RB gene in small-cell lung carcinoma

Loss of heterozygosity for chromosome 13q including the RB locus is a common genetic alteration in small-cell lung carcinoma (SCLC) as well as in retinoblastoma. We examined the RB cDNA sequences of exon 13 to 18 and exon 19 to 23 in 9 SCLC cell lines to detect mutations which cause inactivation of the remaining allele of the RB gene. Internal deletions of RB cDNA were observed in 3 of the 9 SCLC cell lines. In the Lu-24 cell line, a 114 base pairs (bp) deletion corresponding to exon 22 was due to abnormal splicing, which probably resulted from a two-base mutation within genomic exon 22, and aberrant 105 kilodaltons RB protein was detected by immunoprecipitation analysis. A base pair deletion within exon 20 in the Lu-135 cell line and a 1 bp deletion within exon 23 in the Lu-141 cell line were due to the deletions of the corresponding genomic DNA, and each deletion resulted in formation of a premature termination codon. These results indicate that both alleles of the RB genes are inactivated in SCLC by several different mechanisms, including small deletion, mutation and chromosomal loss.

Allele loss on chromosome 16 associated with progression of human hepatocellular carcinoma

Loss of heterozygosity on chromosome 16 is a common genetic alteration in human hepatocellular carcinoma (HCC). To clarify the pathogenetic significance of allele loss on chromosome 16, we performed restriction fragment length polymorphism analysis of 70 surgically resected tumors by using 15 polymorphic DNA markers for chromosome 16. Loss of heterozygosity on chromosome 16 was detected in 36 (52%) of 69 informative cases, and the common region of allele loss in these 36 tumors was located between the HP locus (16q22.1) and the CTRB locus (16q22.3-q23.2). These losses occurred more frequently in HCCs of poor differentiation, of larger size, and with metastasis, whereas they were not detected in HCC at the earliest stage. In addition, these losses were not associated with presence or absence of hepatitis B virus DNA integration or hepatitis C virus infection. These results show that loss of heterozygosity on chromosome 16 is a late event occurring after hepatocarcinogenesis and strongly suggest that this phenomenon is involved in enhancement of tumor aggressiveness during progression of HCC.

Selection of radioresistant cells by vitamin A deficiency in a small cell lung cancer cell line

Radiation sensitivity of a human small cell lung cancer cell line, Lu-134-B cells, cultured in serum-supplemented medium and of cells transferred to and cultured in delipidized serum-supplemented (vitamin A-deficient) medium was studied. The cells cultured in serum-supplemented medium showed the phenotype of classic small cell lung cancer sensitive to radiation, while cells transferred to delipidized serum-supplemented medium showed partial squamous cell differentiation and became resistant to radiation. These results suggest that some small cell lung cancer cells in vitro change their morphology and radiosensitivity depending on the culture conditions. The change in radiosensitivity was reproducible, and was not reversible by culture of the radioresistant cells in delipidized serum-supplemented medium with addition of retinoic acid (vitamin A-sufficient medium) for two months, although squamous cells disappeared. Acquisition of radioresistancy was considered to occur as the result of clonal selective growth in delipidized medium of a minor cell population in the original cell culture, based on a study of chromosome number. It was also found that there was no association of myc-family oncogenes with the changes of radiosensitivity in this cell line.

Isolation of an amplified DNA sequence in stomach cancer

By use of the in-gel DNA renaturation method, the presence of amplified DNA sequences was demonstrated in KATO-III, a cell line established from a signet ring cell carcinoma of the stomach. A DNA fragment from one of these amplified regions in KATO-III cells was cloned and designated SAM0.2; the locus containing the SAM0.2 fragment was referred to as SAM. The SAM locus was shown to be amplified not only in KATO-III cells, but also in three of 24 surgical specimens of stomach cancers and in two of 13 xenografts of human stomach cancers, all of these specimens being poorly differentiated adenocarcinoma or mucinous adenocarcinoma of the stomach. The SAM locus was not amplified in 14 cell lines of cancers of other organs or in 42 surgical specimens of lung cancers.

Frequent expression of receptors for granulocyte-macrophage colony-stimulating factor on human nonhematopoietic tumor cell lines

Receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF) were identified on 9 of 35 (26%) human nonhematopoietic tumor cell lines including non-small cell lung cancer, stomach cancer, colon cancer, and osteosarcoma cells. GM-CSF receptors distributed on these human tumor cells were low affinity types with an equilibrium dissociation constant of 1.5-10.0 nM. Cross-linking studies revealed that the molecular weights of the low affinity GM-CSF receptors were 65-85 kilodaltons. The high affinity receptors identified on hematopoietic cells were not detected on human nonhematopoietic tumor cells which we studied, and we could detect no effects of GM-CSF on cell growth of these tumor cells.

[The effect of L-threo-DOPS on P-300 in parkinsonism]

The P-300 has been recently utilized as an objective electrophysiological index of cognitive function in some neurological disease. Hansch et al first described prolonged latency for the P-300 component in Parkinson disease patients and suggested these measures reflects a common, disrupted aspect of cognitive function in this disease. This cognitive disorder may be caused not only from the dysfunction of dopaminergic system but from non-dopaminergic lesions such as norepinephrine ones. On the other hand, L-threo-DOPS, a non-physiological precursor of norepinephrine, has been used for the treatment of some neurological illness such as the freezing phenomenon in Parkinsonism. In the present study we investigate the effect of L-threo-DOPS on cognitive function in Parkinsonism by measuring P-300 component succeedingly. Twenty-four patients, i.e. 19 cases of Parkinson disease (PD), 3 Juvenile Parkinsonism (JP) and 2 cerebrovascular Parkinsonism, are studied. The latencies of P-300 are significantly shortened after treatment of DOPS compared with those of the previous treatment and placebo administration respectively (p less than 0.05, p less than 0.01). The main factors which have influence upon these shortened latencies are analyzed multivariate analysis. The factor analysis and principal component analysis suggest three main factors such as DOPS, age (onset of age), and duration of illness. The patients' groups are divided into three by cluster analysis. The most effective group mainly consists of JP. The least effective one mainly consists of older, long-duration Parkinson disease patients. And there is another group which consists of younger, short-duration PD cases with moderate effect of DOPS. This tendency seems to suggest the different pathological findings between JP and PD. It is postulated that L-threo-DOPS would raise the level of attention and arousal mediated by norepinephrine neuronal system which may improve the cognitive disorder in Parkinsonism.

[Vestibular ataxia caused by meningeal carcinomatosis]

A 74-year-old man developed progressive deafness and unsteady gait two years after gastrectomy for a gastric cancer. Neurological examination revealed an alert and intelligent Japanese male in no acute distress. The optic fundi were normal. The pupils and the extraocular muscles were normal, however, horizontal nystagmus was noted in right and left gaze. He showed marked bilateral deafness, and loss of caloric response bilaterally. No muscle atrophy nor weakness was noted. His gait was wide-based and ataxic. Tandem gait was impossible. Romberg sign was present. No cerebellar ataxia was noted in the finger-to-nose or the heel-to-knee test. No adiadochokinesis was noted. Hyperextensibility was noted in the lower extremities. Deep reflexes were normal in the upper limbs, and diminished in the lower extremities. Sensation was intact. He showed the jumbling phenomenon, and the disturbance of the righting reflex in the tilt-table examination. Neuroradiological as well as laboratory studies were unremarkable except for the high titer of CEA in the CSF. Four months after his admission, malignant tumor cells were found in the CSF. It seemed likely that he had completely lost bilateral vestibular and auditory functions caused by meningeal carcinomatosis. His disturbance of gait and station was apparently similar to cerebellar ataxic gait, however, he did not have limb ataxia. The cranial CT scans failed to show cerebellar atrophy. It was our impression that his motor disturbance was in all likelihood caused by the bilateral loss of vestibular functions, i.e., vestibular ataxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Introduction of normal chromosome 3p modulates the tumorigenicity of a human renal cell carcinoma cell line YCR

It has been suggested that loss and/or mutational inactivation of a gene or genes on the short arm of chromosome 3 (3p) may play a crucial role in the development of human renal cell carcinoma (RCC). If it is correct, the normal allele may carry suppressor activity for a tumor-associated phenotype(s). In order to test the hypothesis, we introduced a single chromosome containing 3p into a human renal cell carcinoma cell line YCR via microcell fusion, and examined tumorigenicity in nude mice and in vitro growth-properties. The following chromosomes derived from normal human fibroblasts were transferred to YCR or 6-thioguanine-resistant YCR cells: t(X;3) consisting of Xpter greater than Xq26::3p12 greater than 3pter, X, pSV2neo-tagged chromosome 11, and 3/t consisting of pSV2neo-tagged 3p and unknown segments. The introduction of t(X;3) or 3/t resulted in suppression of tumorigenicity or modulation of tumor-growth rate, whereas transfer of other chromosomes, i.e., X and 11, had no effect on tumorigenicity or tumor-growth rate of the cells. In vitro growth properties, i.e., cell-growth in medium containing 1% or 10% serum, growth in soft-agar and saturation density, were not correlated with the tumor-growth. In addition, the tumor-growth rate of 6-thioguanine-resistant segregants which have lost the t(X;3) became similar to that of the parental YCR cells. Thus, the introduction of 3p modulated at least the tumor-growth, indicating the presence on the 3p of a putative tumor-suppressor gene(s) for human RCC.

Frequent loss of heterozygosity on chromosomes 16 and 4 in human hepatocellular carcinoma

By restriction fragment length polymorphism analysis, we examined loss of heterozygosity at 34 loci on 23 chromosomes in 35 surgically resected human hepatocellular carcinomas. Allele losses at the HP locus on chromosome 16q22 and at the MT2P1 locus on chromosome 4p11-q21 were detected in 57% (8/14) and 50% (8/16) of cases, respectively. Loss of heterozygosity on chromosomes 16q and 4 occurred simultaneously in 4 of 7 informative cases for both loci, and seemed to be important in the development of human hepatocellular carcinoma irrespective of the presence of hepatitis B virus infection. In contrast, the incidence of allele loss was low at the other loci, e.g., chromosome 1p, 3p, 11p, 13q or 17p, where one allele is frequently lost in other cancers.

Expression of granulocyte and granulocyte-macrophage colony-stimulating factors by human non-hematopoietic tumor cells

The expression of granulocyte colony-stimulating factor (G-CSF) mRNA was studied in human non-hematopoietic tumors, including 18 cases of lung cancers 10 cases of stomach cancers, three cases of glioblastomas, and one case each of breast phyllode sarcoma, thyroid cancer, and hepatocellular carcinoma. Northern blot analysis detected G-CSF mRNA in two of the lung cancer cases, in one of the glioblastoma cases, and in both the breast phyllode sarcoma and hepatocellular carcinoma cases. Since G-CSF receptors were not detected on the tumor cells by 125I-G-CSF binding assay, G-CSF autocrine loop are probably not involved in the growth of these G-CSF-producing tumors. Interestingly, granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA was concomitantly expressed in most of these G-CSF-producing tumors. No major gene deletions or rearrangements of G-CSF and GM-CSF genes were demonstrated by Southern blot analysis in the tumors expressing G-CSF and GM-CSF mRNAs except for one of the glioblastomas (G3) in which one chromosome 17 allele was deleted. Although the mechanism of the concomitant expression of G-CSF and GM-CSF mRNA is unknown, relatively high frequency of this phenomenon suggests the presence of common transcriptional factors acting on regulatory regions of G-CSF and GM-CSF genomes.

Role of leukocytes in reperfusion injury of skeletal muscle after partial ischemia

These experiments evaluated the leukocyte as a potential source of oxygen free radical (OFR) generation during reperfusion injury in post-ischemic skeletal muscle. The infrarenal aorta of heparinized Sprague-Dawley rats was clamped for 90 min, declamped, and reperfused for 60 min. Hindlimb muscle resting transmembrane potential difference (Em) and high-energy phosphate content were determined at base line, during ischemia, and on reperfusion. Four groups were studied: a control group, a second group receiving superoxide dismutase and catalase (SOD + CAT) on declamping, a third group receiving dimethylmyleran (DMM) 7 days before the experiment to obtain a selective leukopenia (white blood cells = 1,210 +/- 144/mm3, neutrophils = 1.2%), and a fourth group pretreated with allopurinol (ALLO). During the ischemic period, resting Em was significantly depolarized (-78.6 +/- 0.5 mV from -90.3 +/- 0.3; P less than 0.05) in the control group, whereas creatine phosphate (CP) was depleted and ATP maintained. Data collected during the ischemic phase of the three other groups were similar to the control group (P = NS). On reperfusion, persistent depolarization of resting Em was observed despite restoration of muscle CP content in the control and ALLO groups (-75.4 and -77.0 mV, respectively). In contrast, significant repolarization of resting Em was noted after reperfusion in the SOD + CAT and DMM groups (-86.5 and -88.6 mV, respectively). These data implicate leukocyte-generated OFR as mediators of reperfusion-associated cellular membrane injury in postischemic skeletal muscle.