A single-molecule counting approach for convenient and ultrasensitive measurement of restriction digest efficiencies.

Restriction endonucleases play a central role in the microbial immune system against viruses and are widely used in DNA specific cleavage, which is called restriction digestion, for genetic engineering. Herein, we applied digital cell-free protein synthesis as an easy-to-use orthogonal readout means to assess the restriction digest efficiency, a new application of digital bioassays. The digital counting principle enabled an unprecedentedly sensitive trace analysis of undigested DNA at the single-molecule level in a PCR-free manner. Our approach can quantify the template DNA of much lower concentrations that cannot be detected by ensemble-based methods such as gold-standard DNA electrophoresis techniques. The sensitive and quantitative measurements revealed a considerable variation in the digest efficiency among restriction endonucleases, from less than 70% to more than 99%. Intriguingly, none of them showed truly complete digestion within reasonably long periods of reaction time. The same rationale was extended to a multiplexed assay and applicable to any DNA-degrading or genome-editing enzymes. The enzyme kinetic parameters and the flanking sequence-dependent digest efficiency can also be interrogated with the proposed digital counting method. The absolute number of residual intact DNA molecules per microliter was concluded to be at least 107, drawing attention to the residual issue of genetic materials associated with the interpretation of nucleases' behaviors and functions in daily genetic engineering experiments.

Establishment and characterization of human malignant lymphoma cell line derived from uterine cervix.

Human uterine cervical malignant lymphoma (B-cell type) was cultured and the cell line (HIUML) was newly established. The HIUML cells were round in shape and had a tendency to make floating clusters. The cells had a smooth surface or protrusion on the margin of the cytoplasm, and proliferate in floatation. The population doubling time was about 32 hours and 42 or more passages were successfully observed in two years. The HIUML cells were not transplantable into nude mice but were successfully done in the cheek pouch of hamster with formation of malignant lymphoma. Epstein-Barr virus was detected in the HIUML cells.

Establishment and characterization of human glioblastoma cell line (HUBT-n).

We succeeded in primary culture of 3 in 4 cases of glioblastomas. The long-term passage cultures were not done from the primary cultures of original tumor, but glioblastoma cell line (HUBT-n) was established from a xenograft of nude mouse. This line grew well without interruption for 4 years and was subcultivated over 120 times. The cells were spindle like or round in shape and neoplastic and pleomorphic features contained glial fibrillar acid protein (GFAP) and S-100 protein and grew multilayering without contact inhibition. A bough-shaped long projection was noted from a small cell. One of the characteristics of the HUBT-n cells was existence of well developed intermediate filaments in their cytoplasm. The cells proliferated rapidly, and the population doubling time was about 32 hours. The chromosome number showed a narrow distribution of diploid range. Abnormal constitution was observed in all cells by G-band karyotyping. The culture cells were easily transplanted into the subcutis of nude mouse and produced the tumor resembling the original tumor.

Establishment and characterization of a human malignant choroids plexus papilloma cell line (HIBCPP).

A cell line designated "HIBSPP" was established from a human malignant choroids plexus papilloma of 29-year-old Japanese woman. This line grew well without interruption for 3 years and was subcultivated over 70 times. The cells were spindle, oval, and polygonal in shape, and neoplastic and pleomorphic features, a jigsaw puzzle-like arrangement, multilayering and forming papillary structures without contact inhibition. The cells proliferated slowly, and the population doubling time was about 69 hours. The chromosome number showed a wide distribution of aneuploidy. The mode was in the hypotetraploid range, and many marker chromosomes were observed. The culture cells were easily transplanted into the subcutis of nude mice and produced the tumor resembling the original tumor.

Establishment and characterization of a human thyroid carcinoma cell line (HOTHC) producing colony stimulating factor.

A cell line designated HOTHC was established from an anaplastic carcinoma (giant cell type) of the thyroid gland of 80-year-old woman. The HOTHC line grew rapidly in multilayer without contact inhibition, and more than 120 serial passages were made within 27 months. The cells were spindle or polygonal in shape and revealed neoplastic and pleomorphic features. These cells were characterized as containing coloid droplets and poorly developed rough-endoplasmic reticulum in the cytoplasm. Doubling time was about 24 hours and plating efficiency was about 70%. The karyotype exhibits hyperploidy and marker chromosomes, and the modal chromosome number ranged between 77-90. The HOTHC cells were transplanted into the subcutis of BALB/c nude mice and produced anaplatic carcinomas (giant cell type) resembling the original tumor. The HOTHC cells produced colony stimulating factor (CSF) and caused granulocytosis in the mice.

Establishment and characterization of a human gestational choriocarcinoma cell line (HOCC).

Human gestational choriocarcinoma cell line (HOCC) was established from the mouse graft of choriocarcinoma. The HOCC cells were spindle or polygonal in shape and multi-nucleated giant cells, showing neoplastic and pleomorphic features. The cell proliferated stably, and the population doubling time was about 32 hours. The chromosome numbers showed a wide distribution of aneuploidy, the mode was in hypertriploid range and the marker chromosomes were recognized in the several generations. Heterotransplantation was easy, and subcutaneous transplantation of 1 X 10(7) cells in nude mouse formed a tumor composed of choriocarcinoma. It is most noteworthy characteristic of the cell line that it produced human chorionic gonadotropin (hCG) in an in vitro culture system and in vivo in nude mice.

Biological characteristics of cultured cells derived from various types of human brain tumors.

We placed in culture brain tumors from 45 cases (7 cases of astrocytoma, 2 from oligodendrogliomas, 2 glioblastomas, 2 ependymomas, 13 meningiomas, 6 pituitary adenomas, 5 neurinomas, a malignant lymphoma, a choroid plexus papilloma, and 6 metastatic tumors) and succeeded in making a primary culture from 33, and maintained 17 in vitro over a considerable period of time (greater than three months). In the early period of the primary cultures, the astrocytoma cells had cytoplasmic processes which contacted each other, the oligodendroglioma cells were small and spindle-shaped, the glioblastoma cells were neoplastic with pleopmorphic features and possessed cytoplasmic processes, the ependymoma cells formed a rosette-like cell arrangement, the meningioma cells were spindle- or round-shaped cells and characterized as forming psammoma bodies, the pituitary adenoma cells were round- or oval-shaped cells and produced growth hormone (GH), adenocorticoid tropic hormone (ACTH), prolactin, or other hypophyseal hormones, the choroid plexus papilloma cells were round-or polygonal and showed a papillary cell arrangement, the neurinoma cells were spindle- or fibrous-shaped cells, and the malignant lymphoma cells were round and formed cell aggregates floating in the culture medium.

Histogenesis of carcinosarcoma and establishment of leiomyosarcoma cell line (HTMMT) derived from human uterine carcinosarcoma.

A cell line designated HTMMT was established from the human uterine carcinosarcoma (composed of leiomyosarcoma and adenocarcinoma) of a 66-year-old Japanese woman. The cell line grew well and 83 serial passages were successively done within 24 months. The cell line contained spindle- or fibrous-shaped cells that revealed neoplastic and pleomorphic features, and multipled rapidly without contact inhibition. These cells were characterized as possessing myofibrils. The karyotype exhibited hyperploidy and the chromosome number was ranged from 87 to 100. The cells were transplanted into an immune-depressed hamster cheek pouch or into nude mouse skin, but produced no tumors. We supported the combination theory for the histogenesis of the carcinosarcoma.

Establishment and characterization of human uterine cervical epidermoid carcinoma cell line HHUS containing HPV 59 DNA.

The cell line designated HHUS was established from human uterine cervical keratinizing squamous cell carcinoma. The HHUS cell line was subcultivated more than 70 times within 3 years. The cultured cells, polygonal or spindle, with neoplastic and pleomorphic features, appeared epithelial in shape, with a pavement-like arrangement and grew in multi-layers without contact inhibition. The chromosome number was varied from 40 to 88, and the modal number was stable in diploid range. The cultured cells produced keratinizing squamous cell carcinomas by heterotransplantation into the subcutis of nude mice. The HHUS cells were characterized as producing large amounts of SCC, in vitro and possessing HPV-59 DNA genomes.

In vitro culture of various typed meningiomas and characterization of a human malignant meningioma cell line (HKBMM).

We placed on culture the 13 cases of meningiomas, succeeded in making a primary culture of 10 cases and maintained 5 cases in vitro over considerable period of time (over three month), and one cell line derived from a malignant meningioma were established. In the early period of the primary culture, meningioma cells were spindle- or round-shaped cells. In the case of psammomatous type, the cultured cells were characterized as forming psammoma bodies. A cell line designated "HKBMM" was established from a human malignant meningioma occurred from frontal lobe. This line grew well without interruption for 5 years and was subcultivated over 120 times. The cells were spindle and fibrous in shape, and neoplastic and pleomorphic features, and multilayering without contact inhibition. The cells proliferated rapidly, and the population doubling time was about 29 hours. The chromosome number showed a wide distribution of aneuploidy. The mode was in the diploid range. The culture cells were easily transplanted into the subcutis of nude mice and produced the tumor resembling the original tumor.

Establishment and characterization of a human malignant mesothelioma cell line (HMMME).

A cell line designated "HMMME" was established from the pleural fluids of a malignant mesothelioma patient. This line grew well without interruption for 12 years and was subcultured over 200 times. The cells were spindle and roundish in shape and displayed a monolayer sheet in an epithelial pavement cell arrangement. They were neoplastic, had pleomorphic features, and easily formed multilayering without contact inhibition. The cell cytoplasm was strongly positive against anti-vimentin, anti-calretinin and anti-pan-keratin, but negative against anti-BerEP4. The cells proliferated rapidly, and the population doubling time was about 42 hours. Their chromosome number showed a wide distribution of aneuploidy with a mode in the diploid range; many marker chromosomes were observed. The cultured cells were easily transplanted into the subcutaneous of nude mice and produced a tumor classified as a malignant mesothelioma.

Establishment and characterization of a lymphoepithelial-like carcinoma cell line (HUUCLEC) derived from the human uterine cervix.

A cell line designated HUUCLEC was established from a human uterine cervical lymphoepithelial carcinoma obtained from a 61-year-old Japanese woman. The cell line has grown slowly without interruption and serial passages were successively carried out 60 times within 3 years. The cultured cells were spindle or round in shape, showing anaplastic and pleomorphic features, a pavement cell arrangement and multilayering without contact inhibition. The population doubling time of the HUUCLEC line was 72 hours while the chromosomal number varied widely and showed aneuploidy. The modal chromosomal number was stable at the triploid range and marker chromosomes were present; the Ebstein-Barr virus was absent in the cultured cells.

Establishment and characterization of two squamous cell carcinoma cell lines (HYVC and HMVC) derived from vulva.

Two cell lines, HYVC and HMVC, were established from cultures of the squamous cell carcinoma removed from the vulva of females of 37 and 46 years old, respectively. These cell lines were very similar in their biological characteristics, such as morphology (polygonal), growth pattern (32-43 hr of population doubling time, 50-25% of plating efficiency), heterotransplantability (1 x 10(7) cells produced squamous cell carcinomas in the nude mice), genetics (75-78 of modal chromosomal number), and producing the tumor markers (SCC and TPA). The HPV-DNA was not detected in either the HYVC or HMVC lines by using L1-PCR methods, however, it was detected in the HYVC using E6/E7-PCR.