It is now widely accepted that human neoplasms arise as a result of a sequence of mutations affecting the structure of genes involved in growth control. In humans, indirect measurements based on age dependent tumor incidence predict that, on average, the accumulation of 5 to 6 different steps is needed to initiate tumor formation. These mutations do not appear to be random, in that certain neoplasms show prediction for structural aberrations in specific genes. In thyroid tumors, some of gene abnormalities were found. The point mutations of ras oncogenes, predominantly H-ras codon 12, are found in 20-25% of follicular adenomas and papillary carcinomas. Recently, the gene rearrangements of the oncogenes trk and ret were identified in the DNA from papillary carcinomas. About 25% of papillary carcinomas contained an introchromosomal (10q) gene rearrangement involving the tyrosine kinase domain of the ret oncogene with an unknown amino-terminal sequence. The mutations of trk and/or ret were not observed in other thyroid neoplastic phenotypes. In medullary thyroid carcinoma, which is a tumor of the parafollicular, calcitonin-secreting C cell of the thyroid, approximately 20% of patients have autosomal dominant inherited forms. Germ line abnormalities on chromosome 10 are linked to at least one type of genetic medullary thyroid carcinoma (MEN type 2a). In the present time, the person who has the abnormality of gene causing MEN type 2a is able to detect by using DNA marker before the onset of tumor.

Neuroblastoma is a disease with wide spectrum clinically For the evaluation of the biological specificity of this tumor, we examined the expression of Ha-ras p21. The Ha-ras p21 detected in tumor cells showed a statistically significant association with the non-progressed tumor at the diagnosis and the favourable outcome of the patients. The association of Ha-ras p21 with their clinical outcome was closer than those of N-myc amplification. However, the complementary analyses of both Ha-ras p21 and N-myc gene seemed to provide more precise informations relating the patient's care.

A HPV16DNA integrated in a human cancer cell line of the uterine cervix (QG-U) was isolated and cloned. Three kinds of cells (mouse Balb/3T3, Detroit 551 and human keratinocyte) were co-transfected with HPV16DNA and neo DNA with calcium phosphate co-precipitates. Selection of the Transformants and their characteristics were examined. Transformants of mouse Balb/3T3 cells were able to be obtained about 2 weeks after co-transfection. HPV16DNA was integrated in the transformants. The most characteristic change observed in the transformants was the ability to proliferate in serum-free medium. In contrast, two kinds of human diploid cells (Detroit 551 and human keratinocyte) were not transformed by transfection, and ceased growing at almost the same time as nontransfected cells. These results indicate that HPV-DNA transformants are easily selected in cell lines rodents but selection of transformants from human diploid cells is relatively difficult.

The inherited cancer-inducing disease familial polyposis coli (FPC) provides an excellent model not only for studying tumor progression in colorectal cancer but also for elucidating molecular mechanisms in general oncogenesis. This paper reviewed recent remarkable progresses of molecular mechanisms in colorectal tumorigenesis. This is concerned with the various kinds of genetic alterations that accumulate in the development from normal mucosa to adenoma, and then to adenocarcinoma in comparison with FPC and sporadic cases. This review included also information on the localization of FPC major gene. These observations indicate that in cases of colorectal tumorigenesis several genetic alterations may be involved, including activation of K-ras gene, deregulated expression of c-myc gene or c-fos gene and inactivation of tumor suppressor genes such as p53 and DCC genes, as well as the loss of heterozygosity. The observation suggest that adenomas will have undergone several gene or chromosome mutations before reaching to the fully malignant state. Therefore, DNA diagnosis for colorectal tumors in the clinical level may contribute to more accurate prognosis and better results for further therapy.

Retinoblastoma is a malignant tumor that arises in the eyes of children at a frequency of about 1 in 15,000 live births in Japan. Thirty to 40 percent of the patients with retino-blastoma have a heritable predisposition to this tumor. This predisposition is determined by a germinal mutation in the RB gene, which was located at q14 region of chromosome 13 and isolated in 1986. Retinoblastoma will develop in about 90 percent of the persons who carry a mutated RB allele. Thus, it is necessary to develop diagnostic tests that can identify persons who have inherited the mutation. To this end, RBcDNA clones or several polymorphic markers which link to the RB gene have been identified and used for the diagnosis of retinoblastoma predisposition and five RFLP markers within the RB gene have been shown to be useful (Wiggs et al. 1988). Recently we have developed a simple, rapid method for detecting aberrations of RBmRNA including single nucleotide substitutions directly, using polymerase chain reaction-single strand conformation polymorphism analysis (PCR-SSCP) in combination of reverse transcriptase (RT) reaction (RT-PCR-SSCP). For this analysis, we obtain mRNA from 10 ml of peripheral blood and entire procedure including time for isolating mRNA can be completed within 48 hours. By this way we could detect a point mutation of RB gene transcript in peripheral blood cells from two of eight hereditary retinoblastoma patients. We conclude that it is practicable and clinically useful to use this RT-PCR-SSCP analysis of RB gene transcript for direct determination of the risk of retinoblastoma.

The human papillomavirus detection and oncogenes amplifications were studied on DNAs from fifteen cervical cancers. We detected HPV16 and HPV18 using Southern blot hybridization and polymerase chain reaction (PCR) technique. The positive subjects of HPVs were eight cases (53%) observed by Southern blot hybridization and fourteen cases (93%) by PCR technique. The gene amplifications of oncogenes (c-myc and N-myc) were analysed by slot-blot method and were observed in c-myc but not in N-myc. The "LARGE" gene amplification (more than five fold) in c-myc was observed in one case (7%) and the "SMALL" gene amplifications (less than five fold) were observed in six cases (40%) in human cervical cancers. Although one of five cases (20%) with HPV16 was present c-myc gene amplification, all of three cases (100%) with HPV18 were found c-myc gene amplifications. In two out of three cases obtained more than three fold c-myc gene amplifications, HPV were not detectable. It is suggested that the negative correlation between gene amplification and numbers of HPV copies exist in advanced cervical cancers.

The cellular DNA content of lung cancer were measured by flow cytometry on 223 paraffin-embedded specimens prepared from resected lung carcinomas. According to the histological type of lung cancer, the mean values for the DNA Index were 1.41 in adenocarcinoma, 1.39 in squamous cell carcinoma, 1.33 in large cell carcinoma and 1.84 in small cell carcinoma. The DNA Index of small cell carcinoma was thus slightly higher than that of the other histological types, without statistically significant difference. Of 223 lung carcinoma cases, 131 (59.1%) were DNA aneuploidy and 92 (40.9%) were DNA diploidy. DNA aneuploidy was found in 56.1% of adenocarcinomas, 59.5% of squamous cell carcinomas, 53.3% of large cell carcinomas and 100% of small cell carcinomas. According to the staging of the lung cancer, the mean values of the DNA Index were 1.40 in stage I, 1.46 in stage II, 1.36 in stage IIIA, 1.48 in stage IIIB and 1.48 in stage IV. No statistically significant differences were found among these stages. DNA aneuploidy was found in 57.1% of stage I, 57.9% of stage II, 54.7% of stage IIIA, 60.0% of stage IIIB and 75.0% of stage IV. The correlation of DNA content with survival were investigated in 94 cases with stage I non-small cell carcinoma which underwent absolute curative resection. Of 94 cases, the 5-year survival rate of 40 cases with DNA diploidy was 81.1% and a mean survival time 111 months, while this one of the remaining 54 with DNA aneuploidy was 58.4% and a mean survival time 80 months.(ABSTRACT TRUNCATED AT 250 WORDS)

This report described a familial recurrent cardiac myxoma involving mother and daughter. The mother, at 27 year of age, had developed recurrent multiple myxomas in both left and right atrium and right ventricle 4 years after surgical excision of left atrial myxoma. Excision was successful and remains well without signs of recurrence 9 years postoperatively. In an asymptomatic 13-year-old daughter, a recurrent left atrial myxoma was found 3 years after the excision of right atrial myxoma by echocardiographic follow-up at 6 month intervals. Excision of left atrial myxoma was performed and histology showed the essentially the same findings as primary myxoma without signs of malignancy. From an experience of this familial recurrent myxoma and a review of 38 cases of 17 familial cardiac myxoma, it is recommended that wide excision of tumor including surrounding tissues, thorough search for multiple heterotopic tumors at surgery, close postoperative echocardiographic follow-up for at least 5 years, and examination of skin and breast tumor, and endocrine disorder for "complex" myxoma.

Two cases of childhood acute nonlymphocytic leukemia (ANLL) with 21 trisomy as a sole cytogenetic change are reported. The first case was a 4-year-old boy with FAB-M5a. 47, XY, +21 was found in 7 of 12 metaphases at diagnosis and in all 15 metaphases examined at relapse 4 years and 3 months later. The second case was a 14-year-old boy with FAB-M1, all 20 cells examined showed 21 trisomy at diagnosis. His peripheral blood in remission revealed normal male karyotype. Although 21 trisomy is relatively common in ANLL of children, 21 trisomy as a sole anomaly is extremely rare, and to our knowledge, only 2 cases (19 included adult cases) have previously been reported.

The characteristics of a new human clear cell sarcoma (CCSa) cell line, HS-MM, established from the pleural effusion in a 39-year-old man with lung metastasis, have been morphologically studied in vitro and in vivo. HS-MM cells growing on a cover-slip were round or spindle in shape with round nuclei containing extremely prominent nucleoli. Heterotransplantation of the cells into nude mice was easily succeeded following tumor development. Light microscopically, HS-MM cells, both in vitro and in vivo, were positive for anti-S-100 protein and anti-melanoma specific antibodies with immunostain, but no melanin pigment was detected in them. Ultrastructurally, the cells had round euchromatin-rich nuclei with large nucleoli revealing conspicuous nucleolonema, and contained a few mitochondria, rough endoplasmic reticulum and lysosomal dense bodies, besides a large amount of glycogen, but no melanosome in their cytoplasm. HS-MM cells retained and fully expressed morphologically unique characteristics as a CCSa, compatible with amelanotic type of malignant melanoma also. This cell line, HS-MM, therefore, proves to be extremely useful for clinicopathological studies on a CCSa.

The 2.9kb Sac I fragment (EJ2.9), which lacks the previously reported promoter/enhancers of the activated human c-H-ras-1, was used to study the interaction with the tumor virus promoter/enhancers or with the activated c-myc. When EJ2.9 constructs linked to the viral promoter/enhancers or to a viral enhancer even in the antisense orientation was transfected to the mouse cells, 16-39% of the foci induced with those linked in the sense orientation were formed. Further, the transforming activity decreased dramatically when the deletion was introduced from the upstream Sac I site to the 61 bases (-61) upstream of translational initiation codon, but the deletions to -144 did not significantly change the activity. Cotransfections with the activated c-myc were found also to enhance the transforming activity of EJ2.9 constructs either with or without the LTR linked in the antisense orientation. The transfected ras and myc were expressed as 1.2 and 2.5kb mRNAs, respectively, in each transformant. The in vitro mutagenesis suggested that the c-myc protein was involved in the enhancement. These results raise the possibility that the viral enhancers activate a cryptic promoter (s) within the region between -1 and -144 of p21 initiation codon by interacting with the region between -61 and -144 and that the c-myc protein also activates the same or different cryptic promoter(s) within the intron 0 or noncoding region of exon I, thus leading to the enhancement of the EJ2.9 transforming activity.

Retinoblastoma gene has been cloned, and gene product has been characterized precisely. Recently, Wilms' tumor gene has been cloned, and interestingly, its expression was found in genitourinary system, suggesting that anomaly of this system was due to WT gene itself. Molecular analysis performed in colon cancer suggested that several tumor suppressor genes were involved in carcinogenesis and progression of this tumor. These findings revealed that tumor suppressor genes were involved in the development of adult cancer as well as childhood embryonal tumors. Chromosome abnormalities and tumor suppressor gene in childhood cancer are reviewed and referred to future prospects.

A new tumor cell line MEC was established from pleural effusion of a patient of cholaginocarcinoma. In tissue culture, the cell line grew in the sheet of variant cells and showed the epithelial-like pattern. Histologically, the cell line almost showed the same pattern as those in bile and preural effusion from the patient. Electron microscopic observation of this cell line showed the irregular microvilli on the surface of the cell and the desmosome between cells. The doubling time of the cell line was 40.8 hours. Chromosome counts ranged from 61 to 86. The cell line had 9 marker chromosomes and some variant chromosomes. The cell line was transplanted into the subcutaneous of nude mice and formed the tumor. It showed the moderately differentiated tubular adenocarcinoma the same pattern as the primary tumor. We have recognized the producing and releasing of CA19-9 in the serum from the tumor bearing nude mouse and supernate of the medium as the serum from the patient. The presentation of CA19-9 in the cytosol of the cell line and the tumor cells of nude mouse was recognized in Avidin-Biotin-Peroxidase Complex in immunoloperoxidase techniques. The cell line can grow in serum-free medium. On September, 1990, the cell line has been maintained from 70 passages during about 800 days.

Recently, a new and simple method of PCR has been developed and its application is extending widely including clinical research. We are using this method to detect various activated oncogenes within clinical samples from hematological malignancies. We now attempt to use these results as supporting evidences in clinical diagnosis. Here we report several successful results we have obtained through the study of activated RAS oncogenes.